WO2014113558A1 - Methods and compositions for diagnosis and prognosis of renal injury and renal failure - Google Patents

Abstract

The present invention relates to methods and compositions for monitoring, diagnosis, prognosis, and determination of treatment regimens in subjects suffering from or suspected of having a renal injury. In particular, the invention relates to using a measured urine concentration of one or more of TIMP2 and IGFBP7 in combination with one or more of a measured serum creatinine and a measured urine output, which results are correlated to the renal status of the subject, and can be used for diagnosis, prognosis, risk stratification, staging, monitoring, categorizing and determination of further diagnosis and treatment regimens in subjects suffering or at risk of suffering from an injury to renal function, reduced renal function, and/or acute renal failure.

Description

METHODS AND COMPOSITIONS FOR DIAGNOSIS AND PROGNOSIS OF

RENAL INJURY AND RENAL FAILURE

[0001] The present application claims priority to U.S. Provisional Application No. 61/753,723 filed January 17, 2013, which is hereby incorporated in its entirety including all tables, figures, and claims.

BACKGROUND OF THE INVENTION

[0002] The following discussion of the background of the invention is merely provided to aid the reader in understanding the invention and is not admitted to describe or constitute prior art to the present invention.

[0003] The kidney is responsible for water and solute excretion from the body. Its functions include maintenance of acid-base balance, regulation of electrolyte

concentrations, control of blood volume, and regulation of blood pressure. As such, loss of kidney function through injury and/or disease results in substantial morbidity and mortality. A detailed discussion of renal injuries is provided in Harrison's Principles of Internal Medicine, 17^th Ed., McGraw Hill, New York, pages 1741-1830, which are hereby incorporated by reference in their entirety. Renal disease and/or injury may be acute or chronic. Acute and chronic kidney disease are described as follows (from Current Medical Diagnosis & Treatment 2008, 47^th Ed, McGraw Hill, New York, pages 785-815, which are hereby incorporated by reference in their entirety): "Acute renal failure is worsening of renal function over hours to days, resulting in the retention of nitrogenous wastes (such as urea nitrogen) and creatinine in the blood. Retention of these substances is called azotemia. Chronic renal failure (chronic kidney disease) results from an abnormal loss of renal function over months to years".

[0004] Acute renal failure (ARF, also known as acute kidney injury, or AKI) is an abrupt (typically detected within about 48 hours to 1 week) reduction in glomerular filtration. This loss of filtration capacity results in retention of nitrogenous (urea and creatinine) and non-nitrogenous waste products that are normally excreted by the kidney, a reduction in urine output, or both. It is reported that ARF complicates about 5% of hospital admissions, 4-15% of cardiopulmonary bypass surgeries, and up to 30% of intensive care admissions. ARF may be categorized as prerenal, intrinsic renal, or postrenal in causation. Intrinsic renal disease can be further divided into glomerular, tubular, interstitial, and vascular abnormalities. Major causes of ARF are described in the following table, which is adapted from the Merck Manual, 17^th ed., Chapter 222, and which is hereby incorporated by reference in their entirety:

Type Risk Factors

ingestion, myeloma protein, myoglobin

Ureteral obstruction Intrinsic: Calculi, clots, sloughed renal tissue, fungus ball, edema, malignancy, congenital defects; Extrinsic: Malignancy, retroperitoneal fibrosis, ureteral trauma during surgery or high impact injury

Bladder obstruction Mechanical: Benign prostatic hyperplasia, prostate

cancer, bladder cancer, urethral strictures, phimosis, paraphimosis, urethral valves, obstructed indwelling urinary catheter; Neurogenic: Anticholinergic drugs, upper or lower motor neuron lesion

[0005] In the case of ischemic ARF, the course of the disease may be divided into four phases. During an initiation phase, which lasts hours to days, reduced perfusion of the kidney is evolving into injury. Glomerular ultrafiltration reduces, the flow of filtrate is reduced due to debris within the tubules, and back leakage of filtrate through injured epithelium occurs. Renal injury can be mediated during this phase by reperfusion of the kidney. Initiation is followed by an extension phase which is characterized by continued ischemic injury and inflammation and may involve endothelial damage and vascular congestion. During the maintenance phase, lasting from 1 to 2 weeks, renal cell injury occurs, and glomerular filtration and urine output reaches a minimum. A recovery phase can follow in which the renal epithelium is repaired and GFR gradually recovers. Despite this, the survival rate of subjects with ARF may be as low as about 60%.

[0006] Acute kidney injury caused by radiocontrast agents (also called contrast media) and other nephrotoxins such as cyclosporine, antibiotics including

aminoglycosides and anticancer drugs such as cisplatin manifests over a period of days to about a week. Contrast induced nephropathy (CIN, which is AKI caused by radiocontrast agents) is thought to be caused by intrarenal vasoconstriction (leading to ischemic injury) and from the generation of reactive oxygen species that are directly toxic to renal tubular epithelial cells. CIN classically presents as an acute (onset within 24-48h) but reversible (peak 3-5 days, resolution within 1 week) rise in blood urea nitrogen and serum creatinine.

[0007] A commonly reported criteria for defining and detecting AKI is an abrupt (typically within about 2-7 days or within a period of hospitalization) elevation of serum creatinine. Although the use of serum creatinine elevation to define and detect AKI is well established, the magnitude of the serum creatinine elevation and the time over which it is measured to define AKI varies considerably among publications. Traditionally, relatively large increases in serum creatinine such as 100%, 200%, an increase of at least 100% to a value over 2 mg/dL and other definitions were used to define AKI. However, the recent trend has been towards using smaller serum creatinine rises to define AKI. The relationship between serum creatinine rise, AKI and the associated health risks are reviewed in Praught and Shlipak, Curr Opin Nephrol Hypertens 14:265-270, 2005 and Chertow et al, J Am Soc Nephrol 16: 3365-3370, 2005, which, with the references listed therein, are hereby incorporated by reference in their entirety. As described in these publications, acute worsening renal function (AKI) and increased risk of death and other detrimental outcomes are now known to be associated with very small increases in serum creatinine. These increases may be determined as a relative (percent) value or a nominal value. Relative increases in serum creatinine as small as 20% from the pre-injury value have been reported to indicate acutely worsening renal function (AKI) and increased health risk, but the more commonly reported value to define AKI and increased health risk is a relative increase of at least 25%. Nominal increases as small as 0.3 mg/dL, 0.2 mg/dL or even 0.1 mg/dL have been reported to indicate worsening renal function and increased risk of death. Various time periods for the serum creatinine to rise to these threshold values have been used to define AKI, for example, ranging from 2 days, 3 days, 7 days, or a variable period defined as the time the patient is in the hospital or intensive care unit. These studies indicate there is not a particular threshold serum creatinine rise (or time period for the rise) for worsening renal function or AKI, but rather a continuous increase in risk with increasing magnitude of serum creatinine rise.

[0008] One study (Lassnigg et all, J Am Soc Nephrol 15: 1597-1605, 2004, hereby incorporated by reference in its entirety) investigated both increases and decreases in serum creatinine. Patients with a mild fall in serum creatinine of -0.1 to -0.3 mg/dL following heart surgery had the lowest mortality rate. Patients with a larger fall in serum creatinine (more than or equal to -0.4 mg/dL) or any increase in serum creatinine had a larger mortality rate. These findings caused the authors to conclude that even very subtle changes in renal function (as detected by small creatinine changes within 48 hours of surgery) seriously effect patient's outcomes. In an effort to reach consensus on a unified classification system for using serum creatinine to define AKI in clinical trials and in clinical practice, Bellomo et al, Crit Care. 8(4):R204-12, 2004, which is hereby incorporated by reference in its entirety, proposes the following classifications for stratifying AKI patients:

"Risk": serum creatinine increased 1.5 fold from baseline OR urine production of <0.5 ml/kg body weight/hr for 6 hours;

"Injury": serum creatinine increased 2.0 fold from baseline OR urine production <0.5 ml/kg/hr for 12 h;

"Failure": serum creatinine increased 3.0 fold from baseline OR creatinine >355 μιηοΐ/ΐ (with a rise of >44) or urine output below 0.3 ml/kg/hr for 24 h or anuria for at least 12 hours;

And included two clinical outcomes:

"Loss": persistent need for renal replacement therapy for more than four weeks.

"ESRD": end stage renal disease— the need for dialysis for more than 3 months.

[0009] These criteria are called the RIFLE criteria, which provide a useful clinical tool to classify renal status. As discussed in Kellum, Crit. Care Med. 36: S141-45, 2008 and Ricci et al., Kidney Int. 73, 538-546, 2008, each hereby incorporated by reference in its entirety, the RIFLE criteria provide a uniform definition of AKI which has been validated in numerous studies.

More recently, Mehta et al, Crit. Care 11 :R31 (doi: 10.1186.cc5713), 2007, hereby incorporated by reference in its entirety, proposes the following similar classifications for stratifying AKI patients, which have been modified from RIFLE:

"Stage I": increase in serum creatinine of more than or equal to 0.3 mg/dL (> 26.4 μιηοΙ/L) or increase to more than or equal to 150% (1.5-fold) from baseline OR urine output less than 0.5 mL/kg per hour for more than 6 hours;

"Stage Π": increase in serum creatinine to more than 200% (> 2-fold) from baseline OR urine output less than 0.5 mL/kg per hour for more than 12 hours;

"Stage III": increase in serum creatinine to more than 300% (> 3-fold) from baseline OR serum creatinine > 354 μιηοΙ/L accompanied by an acute increase of at least 44 μιηοΙ/L OR urine output less than 0.3 mL/kg per hour for 24 hours or anuria for 12 hours.

[0010] The CIN Consensus Working Panel (McCollough et al, Rev Cardiovasc Med. 2006;7(4):177-197, hereby incorporated by reference in its entirety) uses a serum creatinine rise of 25% to define Contrast induced nephropathy (which is a type of AKI). Although various groups propose slightly different criteria for using serum creatinine to detect AKI, the consensus is that small changes in serum creatinine, such as 0.3 mg/dL or 25%, are sufficient to detect AKI (worsening renal function) and that the magnitude of the serum creatinine change is an indicator of the severity of the AKI and mortality risk.

[0011] Although serial measurement of serum creatinine over a period of days is an accepted method of detecting and diagnosing AKI and is considered one of the most important tools to evaluate AKI patients, serum creatinine is generally regarded to have several limitations in the diagnosis, assessment and monitoring of AKI patients. The time period for serum creatinine to rise to values (e.g., a 0.3 mg/dL or 25% rise) considered diagnostic for AKI can be 48 hours or longer depending on the definition used. Since cellular injury in AKI can occur over a period of hours, serum creatinine elevations detected at 48 hours or longer can be a late indicator of injury, and relying on serum creatinine can thus delay diagnosis of AKI. Furthermore, serum creatinine is not a good indicator of the exact kidney status and treatment needs during the most acute phases of AKI when kidney function is changing rapidly. Some patients with AKI will recover fully, some will need dialysis (either short term or long term) and some will have other detrimental outcomes including death, major adverse cardiac events and chronic kidney disease. Because serum creatinine is a marker of filtration rate, it does not differentiate between the causes of AKI (pre-renal, intrinsic renal, post-renal obstruction,

atheroembolic, etc) or the category or location of injury in intrinsic renal disease (for example, tubular, glomerular or interstitial in origin). Urine output is similarly limited, Knowing these things can be of vital importance in managing and treating patients with AKI.

[0012] These limitations underscore the need for better methods to detect and assess AKI, particularly in the early and subclinical stages, but also in later stages when recovery and repair of the kidney can occur. Furthermore, there is a need to better identify patients who are at risk of having an AKI.

BRIEF SUMMARY OF THE INVENTION

[0013] It is an object of the invention to provide methods and compositions for evaluating renal function in a subject. As described herein, a measured urine concentration of one or more of TIMP2 and IGFBP7 in combination with a measured concentration of one or more of serum creatinine and urine output are correlated to the renal status of the subject, and can be used for diagnosis, prognosis, risk stratification, staging, monitoring, categorizing and determination of further diagnosis and treatment regimens in subjects suffering or at risk of suffering from an injury to renal function, reduced renal function, and/or acute renal failure (also called acute kidney injury).

Preferred combinations include urine TIMP2 x urine IGFBP7 x serum creatinine; urine TIMP2 x urine IGFBP7 / urine output; urine TIMP2 x urine IGFBP7 x serum creatinine / urine output; urine TIMP2 x serum creatinine; urine TIMP2 / urine output; urine TIMP2 x serum creatinine / urine output; urine IGFBP7 x serum creatinine; urine IGFBP7 / urine output; and urine IGFBP7 x serum creatinine / urine output.

[0014] The kidney injury markers of the present invention may be used, individually or in panels comprising a plurality of kidney injury markers, for risk stratification (that is, to identify subjects at risk for a future injury to renal function, for future progression to reduced renal function, for future progression to ARF, for future improvement in renal function, etc.); for diagnosis of existing disease (that is, to identify subjects who have suffered an injury to renal function, who have progressed to reduced renal function, who have progressed to ARF, etc.); for monitoring for deterioration or improvement of renal function; and for predicting a future medical outcome, such as improved or worsening renal function, a decreased or increased mortality risk, a decreased or increased risk that a subject will require renal replacement therapy (i.e., hemodialysis, peritoneal dialysis, hemofiltration, and/or renal transplantation, a decreased or increased risk that a subject will recover from an injury to renal function, a decreased or increased risk that a subject will recover from ARF, a decreased or increased risk that a subject will progress to end stage renal disease, a decreased or increased risk that a subject will progress to chronic renal failure, a decreased or increased risk that a subject will suffer rejection of a transplanted kidney, etc.

[0015] In a first aspect, the present invention relates to methods for evaluating renal status in a subject. These methods comprise determining a measured urine concentration of one or more of TIMP2 and IGFBP7 in combination with one or more of a measured concentration of serum creatinine and a measured urine output, the results of which are correlated to the renal status of the subject. This correlation to renal status may include correlating the assay result(s) to one or more of risk stratification, diagnosis, prognosis, staging, classifying and monitoring of the subject as described herein. Thus, the present invention utilizes one or more kidney injury markers of the present invention for the evaluation of renal injury.

[0016] In certain embodiments, the methods for evaluating renal status described herein are methods for risk stratification of the subject; that is, assigning a likelihood of one or more future changes in renal status to the subject. In preferred risk stratification embodiments, these methods comprise determining a subject's risk for a future injury to renal function by combining the assay result(s) into a single "risk value" which is then correlated to a likelihood of such a future injury to renal function. The resulting risk value is preferably a "positive going" kidney injury marker, whereby an increased likelihood of suffering a future injury to renal function is assigned to the subject when the measured concentration is above a threshold, relative to a likelihood assigned when the measured concentration is below the threshold. In other preferred risk stratification embodiments, these methods comprise determining a subject's risk for future reduced renal function, determining a subject's likelihood for a future improvement in renal function, determining a subject's risk for progression to ARF, and/or determining a subject's outcome risk. In such risk stratification embodiments, preferably the likelihood or risk assigned is that an event of interest is more or less likely to occur within 180 days of the time at which the body fluid sample is obtained from the subject. In particularly preferred embodiments, the likelihood or risk assigned relates to an event of interest occurring within a shorter time period such as 18 months, 120 days, 90 days, 60 days, 45 days, 30 days, 21 days, 14 days, 7 days, 5 days, 96 hours, 72 hours, 48 hours, 36 hours, 24 hours, 12 hours, or less. A risk at 0 hours of the time at which the body fluid sample is obtained from the subject is equivalent to diagnosis of a current condition. Preferred risk values are calculated as urine TIMP2 x urine IGFBP7 x serum creatinine; urine TIMP2 x urine IGFBP7 / urine output; urine TIMP2 x urine IGFBP7 x serum creatinine / urine output; urine TIMP2 x serum creatinine; urine TIMP2 / urine output; urine TIMP2 x serum creatinine / urine output; urine IGFBP7 x serum creatinine; urine IGFBP7 / urine output; and urine IGFBP7 x serum creatinine / urine output.

[0017] In preferred risk stratification embodiments, the subject is selected for risk stratification based on the pre-existence in the subject of one or more known risk factors for prerenal, intrinsic renal, or postrenal ARF. For example, a subject undergoing or having undergone major vascular surgery, coronary artery bypass, or other cardiac surgery; a subject having pre-existing congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, glomerular filtration below the normal range, cirrhosis, serum creatinine above the normal range, or sepsis; or a subject exposed to NSAIDs, cyclosporins, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin are all preferred subjects for monitoring risks according to the methods described herein. This list is not meant to be limiting. By "pre-existence" in this context is meant that the risk factor exists at the time the body fluid sample is obtained from the subject. In particularly preferred embodiments, a subject is chosen for risk stratification based on an existing diagnosis of injury to renal function, reduced renal function, or ARF.

[0018] In preferred diagnostic embodiments, these methods comprise determining a subject's current renal function by combining the assay result(s) into a single "diagnostic value" which is then correlated to a likelihood of a particular diagnosis. The resulting diagnostic value is preferably a "positive going" kidney injury marker, whereby an increased likelihood of a diagnosis is assigned to the subject when the measured concentration is above a threshold, relative to a likelihood assigned when the measured concentration is below the threshold. In preferred diagnostic embodiments, these methods comprise diagnosing the occurrence or nonoccurrence of an injury to renal function, diagnosing the occurrence or nonoccurrence of reduced renal function, diagnosing the occurrence or nonoccurrence of ARF, diagnosing a subject as being in need of renal replacement therapy, and/or diagnosing a subject as being in need of renal transplantation. Preferred diagnostic values are calculated as urine TIMP2 x urine IGFBP7 x serum creatinine; urine TIMP2 x urine IGFBP7 / urine output; urine TIMP2 x urine IGFBP7 x serum creatinine / urine output; urine TIMP2 x serum creatinine; urine TIMP2 / urine output; urine TIMP2 x serum creatinine / urine output; urine IGFBP7 x serum creatinine; urine IGFBP7 / urine output; and urine IGFBP7 x serum creatinine / urine output.

[0019] In still other embodiments, the methods for evaluating renal status described herein are methods for monitoring a renal injury in the subject; that is, assessing whether or not renal function is improving or worsening in a subject who has suffered from an injury to renal function, reduced renal function, or ARF. In preferred monitoring embodiments, these methods comprise determining a subject's current renal function by combining the assay result(s) into a single "monitoring value" which is then correlated to a likelihood of a particular clinical outcome. The resulting monitoring value is preferably a "positive going" kidney injury marker, whereby a decreased likelihood of a improvement is assigned to the subject when the measured concentration is above a threshold, relative to a likelihood assigned when the measured concentration is below the threshold. Preferred monitoring values are calculated as urine TIMP2 x urine IGFBP7 x serum creatinine; urine TIMP2 x urine IGFBP7 / urine output; urine TIMP2 x urine IGFBP7 x serum creatinine / urine output; urine TIMP2 x serum creatinine; urine TIMP2 / urine output; urine TIMP2 x serum creatinine / urine output; urine IGFBP7 x serum creatinine; urine IGFBP7 / urine output; and urine IGFBP7 x serum creatinine / urine output.

[0020] In preferred monitoring embodiments, these methods comprise monitoring renal status in a subject suffering from reduced renal function, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of a change in renal status in the subject. In yet other preferred monitoring embodiments, these methods comprise monitoring renal status in a subject suffering from acute renal failure, and the assay result(s) is/are correlated to the occurrence or nonoccurrence of a change in renal status in the subject. In other additional preferred monitoring embodiments, these methods comprise monitoring renal status in a subject at risk of an injury to renal function due to the pre-existence of one or more known risk factors for prerenal, intrinsic renal, or postrenal ARF, and the assay result(s) is/are correlated to the occurrence or

nonoccurrence of a change in renal status in the subject.

[0021] In still other embodiments, the methods for evaluating renal status described herein are methods for classifying a renal injury in the subject; that is, determining whether a renal injury in a subject is prerenal, intrinsic renal, or postrenal; and/or further subdividing these classes into subclasses such as acute tubular injury, acute

glomerulonephritis acute tubulointerstitial nephritis, acute vascular nephropathy, or infiltrative disease; and/or assigning a likelihood that a subject will progress to a particular RIFLE stage. In preferred classification embodiments, these methods comprise determining whether a renal injury in a subject is prerenal, intrinsic renal, or postrenal; and/or further subdividing these classes into subclasses such as acute tubular injury, acute glomerulonephritis acute tubulointerstitial nephritis, acute vascular nephropathy, or infiltrative disease; and/or assigning a likelihood that a subject will progress to a particular RIFLE stage, and the assay result(s) is/are correlated to the injury classification for the subject. For example, the measured concentration may be compared to a threshold value, and when the measured concentration is above the threshold, a particular classification is assigned; alternatively, when the measured concentration is below the threshold, a different classification may be assigned to the subject.

[0022] A variety of methods may be used by the skilled artisan to arrive at a desired threshold value for use in these methods. For example, the threshold value may be determined from a population of normal subjects by selecting a concentration

representing the 75th, 85th, 90th, 95th, or 99th percentile of a kidney injury marker measured in such normal subjects. Alternatively, the threshold value may be determined from a "diseased" population of subjects, e.g., those suffering from an injury or having a predisposition for an injury (e.g., progression to ARF or some other clinical outcome such as death, dialysis, renal transplantation, etc.), by selecting a concentration representing the 75th, 85th, 90th, 95th, or 99th percentile of a kidney injury marker measured in such subjects. In another alternative, the threshold value may be determined from a prior measurement of a kidney injury marker in the same subject; that is, a temporal change in the level of a kidney injury marker in the subject may be used to assign risk to the subject.

[0023] The foregoing discussion is not meant to imply, however, that the kidney injury markers of the present invention must be compared to corresponding individual thresholds. Methods for combining assay results can comprise the use of multivariate logistical regression, loglinear modeling, neural network analysis, n-of-m analysis, decision tree analysis, calculating ratios of markers, etc. This list is not meant to be limiting. In these methods, a composite result which is determined by combining individual markers may be treated as if it is itself a marker; that is, a threshold may be determined for the composite result as described herein for individual markers, and the composite result for an individual patient compared to this threshold.

[0024] The ability of a particular test to distinguish two populations can be established using ROC analysis. For example, ROC curves established from a "first" subpopulation which is predisposed to one or more future changes in renal status, and a "second" subpopulation which is not so predisposed can be used to calculate a ROC curve, and the area under the curve provides a measure of the quality of the test.

Preferably, the tests described herein provide a ROC curve area greater than 0.5, preferably at least 0.6, more preferably at least 0.7, still more preferably at least 0.8, even more preferably at least 0.9, and most preferably at least 0.95. [0025] In certain aspects, the measured concentration of one or more kidney injury markers, or a composite of such markers, may be treated as continuous variables. For example, any particular concentration can be converted into a corresponding probability of a future reduction in renal function for the subject, the occurrence of an injury, a classification, etc. In yet another alternative, a threshold that can provide an acceptable level of specificity and sensitivity in separating a population of subjects into "bins" such as a "first" subpopulation (e.g., which is predisposed to one or more future changes in renal status, the occurrence of an injury, a classification, etc.) and a "second" subpopulation which is not so predisposed. A threshold value is selected to separate this first and second population by one or more of the following measures of test accuracy: an odds ratio greater than 1, preferably at least about 2 or more or about 0.5 or less, more preferably at least about 3 or more or about 0.33 or less, still more preferably at least about 4 or more or about 0.25 or less, even more preferably at least about 5 or more or about 0.2 or less, and most preferably at least about 10 or more or about 0.1 or less; a specificity of greater than 0.5, preferably at least about 0.6, more preferably at least about 0.7, still more preferably at least about 0.8, even more preferably at least about 0.9 and most preferably at least about 0.95, with a corresponding sensitivity greater than 0.2, preferably greater than about 0.3, more preferably greater than about 0.4, still more preferably at least about 0.5, even more preferably about 0.6, yet more preferably greater than about 0.7, still more preferably greater than about 0.8, more preferably greater than about 0.9, and most preferably greater than about 0.95;

a sensitivity of greater than 0.5, preferably at least about 0.6, more preferably at least about 0.7, still more preferably at least about 0.8, even more preferably at least about 0.9 and most preferably at least about 0.95, with a corresponding specificity greater than 0.2, preferably greater than about 0.3, more preferably greater than about 0.4, still more preferably at least about 0.5, even more preferably about 0.6, yet more preferably greater than about 0.7, still more preferably greater than about 0.8, more preferably greater than about 0.9, and most preferably greater than about 0.95;

at least about 75% sensitivity, combined with at least about 75% specificity;

a positive likelihood ratio (calculated as sensitivity/(l -specificity)) of greater than 1, at least about 2, more preferably at least about 3, still more preferably at least about 5, and most preferably at least about 10; or a negative likelihood ratio (calculated as (1 -sensitivity )/specificity) of less than 1, less than or equal to about 0.5, more preferably less than or equal to about 0.3, and most preferably less than or equal to about 0.1.

The term "about" in the context of any of the above measurements refers to +/- 5% of a given measurement.

[0026] Multiple thresholds may also be used to assess renal status in a subject. For example, a "first" subpopulation which is predisposed to one or more future changes in renal status, the occurrence of an injury, a classification, etc., and a "second"

subpopulation which is not so predisposed can be combined into a single group. This group is then subdivided into three or more equal parts (known as tertiles, quartiles, quintiles, etc., depending on the number of subdivisions). An odds ratio is assigned to subjects based on which subdivision they fall into. If one considers a tertile, the lowest or highest tertile can be used as a reference for comparison of the other subdivisions. This reference subdivision is assigned an odds ratio of 1. The second tertile is assigned an odds ratio that is relative to that first tertile. That is, someone in the second tertile might be 3 times more likely to suffer one or more future changes in renal status in comparison to someone in the first tertile. The third tertile is also assigned an odds ratio that is relative to that first tertile.

[0027] In certain embodiments, the assay method is an immunoassay. Antibodies for use in such assays will specifically bind a full length kidney injury marker of interest, and may also bind one or more polypeptides that are "related" thereto, as that term is defined hereinafter. Numerous immunoassay formats are known to those of skill in the art.

Preferred body fluid samples are selected from the group consisting of urine, blood, serum, saliva, tears, and plasma. In the case of those kidney injury markers which are membrane proteins as described hereinafter, preferred assays detect soluble forms thereof.

[0028] The foregoing method steps should not be interpreted to mean that the kidney injury marker assay result(s) is/are used in isolation in the methods described herein. Rather, additional variables or other clinical indicia may be included in the methods described herein. For example, a risk stratification, diagnostic, classification, monitoring, etc. method may combine the assay result(s) with one or more variables measured for the subject selected from the group consisting of demographic information (e.g., weight, sex, age, race), medical history (e.g., family history, type of surgery, pre-existing disease such as aneurism, congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, or sepsis, type of toxin exposure such as NSAIDs, cyclosporins, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin), clinical variables (e.g., blood pressure, temperature, respiration rate), risk scores (APACHE score, PREDICT score, TIMI Risk Score for UA/NSTEMI, Framingham Risk Score, risk scores of Thakar et al. (J. Am. Soc. Nephrol. 16: 162-68, 2005), Mehran et al. (J. Am. Coll. Cardiol. 44: 1393-99, 2004), Wijeysundera et al. (JAMA 297: 1801-9, 2007), Goldstein and Chawla (Clin. J. Am. Soc. Nephrol. 5: 943-49, 2010), or Chawla et al. (Kidney Intl. 68: 2274-80, 2005)), a glomerular filtration rate, an estimated glomerular filtration rate, a urine production rate, a serum or plasma creatinine concentration, a urine creatinine concentration, a fractional excretion of sodium, a urine sodium concentration, a urine creatinine to serum or plasma creatinine ratio, a urine specific gravity, a urine osmolality, a urine urea nitrogen to plasma urea nitrogen ratio, a plasma BUN to creatnine ratio, a renal failure index calculated as urine sodium / (urine creatinine / plasma creatinine), a serum or plasma neutrophil gelatinase (NGAL) concentration, a urine NGAL concentration, a serum or plasma cystatin C concentration, a serum or plasma cardiac troponin concentration, a serum or plasma BNP concentration, a serum or plasma NTproBNP concentration, and a serum or plasma proBNP concentration. Other measures of renal function which may be combined with one or more kidney injury marker assay result(s) are described hereinafter and in Harrison's Principles of Internal Medicine, 17^th Ed., McGraw Hill, New York, pages 1741-1830, and Current Medical Diagnosis & Treatment 2008, 47^th Ed, McGraw Hill, New York, pages 785-815, each of which are hereby incorporated by reference in their entirety.

[0029] When more than one marker is measured, the individual markers may be measured in samples obtained at the same time, or may be determined from samples obtained at different (e.g., an earlier or later) times. The individual markers may also be measured on the same or different body fluid samples. For example, one kidney injury marker may be measured in a serum or plasma sample and another kidney injury marker may be measured in a urine sample. In addition, assignment of a likelihood may combine an individual kidney injury marker assay result with temporal changes in one or more additional variables. [0030] In various related aspects, the present invention also relates to devices and kits for performing the methods described herein. Suitable kits comprise reagents sufficient for performing an assay for at least one of the described kidney injury markers, together with instructions for performing the described threshold comparisons.

[0031] In certain embodiments, reagents for performing such assays are provided in an assay device, and such assay devices may be included in such a kit. Preferred reagents can comprise one or more solid phase antibodies, the solid phase antibody comprising antibody that detects the intended biomarker target(s) bound to a solid support. In the case of sandwich immunoassays, such reagents can also include one or more detectably labeled antibodies, the detectably labeled antibody comprising antibody that detects the intended biomarker target(s) bound to a detectable label. Additional optional elements that may be provided as part of an assay device are described hereinafter.

[0032] Detectable labels may include molecules that are themselves detectable (e.g., fluorescent moieties, electrochemical labels, eel (electrochemical luminescence) labels, metal chelates, colloidal metal particles, etc.) as well as molecules that may be indirectly detected by production of a detectable reaction product (e.g., enzymes such as horseradish peroxidase, alkaline phosphatase, etc.) or through the use of a specific binding molecule which itself may be detectable (e.g., a labeled antibody that binds to the second antibody, biotin, digoxigenin, maltose, oligohistidine, 2,4-dintrobenzene, phenylarsenate, ssDNA, dsDNA, etc.).

[0033] Generation of a signal from the signal development element can be performed using various optical, acoustical, and electrochemical methods and instruments well known in the art. Examples of detection modes include fluorescence, radiochemical detection, reflectance, absorbance, amperometry, conductance, impedance,

interferometry, ellipsometry, etc. In certain of these methods, the solid phase antibody is coupled to a transducer (e.g., a diffraction grating, electrochemical sensor, etc) for generation of a signal, while in others, a signal is generated by a transducer that is spatially separate from the solid phase antibody (e.g., a fluorometer that employs an excitation light source and an optical detector). This list is not meant to be limiting. Antibody-based biosensors may also be employed to determine the presence or amount of analytes that optionally eliminate the need for a labeled molecule. DETAILED DESCRIPTION OF THE INVENTION

[0034] The present invention relates to methods and compositions for diagnosis, differential diagnosis, risk stratification, monitoring, classifying and determination of treatment regimens in subjects suffering or at risk of suffering from injury to renal function, reduced renal function and/or acute renal failure through measurement of one or more kidney injury markers. In various embodiments, a measured urine concentration of one or more of TIMP2 and IGFBP7 in combination with a measured concentration of one or more of serum creatinine and urine output are correlated to the renal status of the subject. Preferred combinations include urine TIMP2 x urine IGFBP7 x serum creatinine; urine TIMP2 x urine IGFBP7 / urine output; urine TIMP2 x urine IGFBP7 x serum creatinine / urine output; urine TIMP2 x serum creatinine; urine TIMP2 / urine output; urine TIMP2 x serum creatinine / urine output; urine IGFBP7 x serum creatinine; urine IGFBP7 / urine output; and urine IGFBP7 x serum creatinine / urine output. In these expressions, the operators "x" and "/" indicate multiplication and division, respectively. Other methods of combining assay results/clinical indicia can comprise the use of multivariate logistical regression, loglinear modeling, neural network analysis, n-of-m analysis, decision tree analysis, etc. This list is not meant to be limiting.

[0035] For purposes of this document, the following definitions apply:

[0036] As used herein, an "injury to renal function" is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, still more preferably within 48 hours, even more preferably within 24 hours, and most preferably within 12-18 hours) measurable reduction in a measure of renal function. Such an injury may be identified, for example, by a decrease in glomerular filtration rate or estimated GFR, a reduction in urine output, an increase in serum creatinine, an increase in serum cystatin C, a requirement for renal replacement therapy, etc. "Improvement in Renal Function" is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) measurable increase in a measure of renal function. Preferred methods for measuring and/or estimating GFR are described hereinafter.

[0037] As used herein, "reduced renal function" is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) reduction in kidney function identified by an absolute increase in serum creatinine of greater than or equal to 0.1 mg/dL (> 8.8 μιηοΙ/L), a percentage increase in serum creatinine of greater than or equal to 20% (1.2-fold from baseline), or a reduction in urine output (documented oliguria of less than 0. 5 ml/kg per hour).

[0038] As used herein, "acute renal failure" or "ARF' is an abrupt (within 14 days, preferably within 7 days, more preferably within 72 hours, and still more preferably within 48 hours) reduction in kidney function identified by an absolute increase in serum creatinine of greater than or equal to 0.3 mg/dl (> 26.4 μιηοΐ/ΐ), a percentage increase in serum creatinine of greater than or equal to 50% (1. 5-fold from baseline), or a reduction in urine output (documented oliguria of less than 0.5 ml/kg per hour for at least 6 hours). This term is synonymous with "acute kidney injury" or "AKI."

[0039] As used herein, the terms "Metalloproteinase inhibitor 2" or "TIMP2" refer to one or more polypeptides present in a biological sample that are derived from the Metalloproteinase inhibitor 2 precursor. The human precursor sequence (Swiss-Prot P16035 (SEQ ID NO: 1)) is as follows:

10 20 30 40 50 6 0

MGAAARTLRL ALGLLLLATL LRPADACSCS PVHPQQAFCN ADWIRAKAV SEKEVDSGND

70 80 90 100 110 120

IYGNPIKRIQ YEIKQIKMFK GPEKDIEFIY TAPSSAVCGV SLDVGGKKEY LIAGKAEGDG

130 140 150 16 0 170 180

KMHITLCDFI VPWDTLSTTQ KKSLNHRYQM GCECKITRCP MIPCYISSPD ECLWMDWVTE

190 200 210 220

KNINGHQAKF FACIKRSDGS CAWYRGAAPP KQEFLDIEDP

[0040] The following domains have been identified in Metalloproteinase inhibitor 2:

Residues Length Domain ID

1 -26 26 Signal peptide

27-220 194 Metalloproteinase inhibitor 2

[0041] As used herein, the terms "Insulin-like growth factor-binding protein 7" or "IGFBP7" refer to one or more polypeptides present in a biological sample that are derived from the Insulin-like growth factor-binding protein 7 precursor. The human precursor sequence (Swiss-Prot Q16270 (SEQ ID NO: 2)) is as follows: 10 20 30 40 50 60

MERPSLRALL LGAAGLLLLL LPLSS S S S SD TCGPCEPASC PPLPPLGCLL GETRDACGCC

70 80 90 100 110 120

PMCARGEGEP CGGGGAGRGY CAPGMECVKS RKRRKGKAGA AAGGPGVSGV CVCKSRYPVC

130 140 150 160 170 180

GSDGTTYPSG CQLRAASQRA ESRGEKAI TQ VSKGTCEQGP S IVTPPKD IW NVTGAQVYLS

190 200 210 220 230 240

CEVI GIPTPV LIWNKVKRGH YGVQRTELLP GDRDNLAIQT RGGPEKHEVT GWVLVSPLSK

250 26 0 270 280

EDAGEYECHA SNSQGQASAS AKI TWDALH E IPVKKGEGA EL

[0001] The following domains have been identified in Insulin- like growth factor- binding protein 7:

Residues Length Domain ID

1-26 26 Signal peptide

27-282 256 Insulin-like growth factor-binding protein 7

[0042] As used herein, the term "relating a signal to the presence or amount" of an analyte reflects the following understanding. Assay signals are typically related to the presence or amount of an analyte through the use of a standard curve calculated using known concentrations of the analyte of interest. As the term is used herein, an assay is "configured to detect" an analyte if an assay can generate a detectable signal indicative of the presence or amount of a physiologically relevant concentration of the analyte.

Because an antibody epitope is on the order of 8 amino acids, an immunoassay configured to detect a marker of interest will also detect polypeptides related to the marker sequence, so long as those polypeptides contain the epitope(s) necessary to bind to the antibody or antibodies used in the assay. The term "related marker" as used herein with regard to a biomarker such as one of the kidney injury markers described herein refers to one or more fragments, variants, etc., of a particular marker or its biosynthetic parent that may be detected as a surrogate for the marker itself or as independent biomarkers. The term also refers to one or more polypeptides present in a biological sample that are derived from the biomarker precursor complexed to additional species, such as binding proteins, receptors, heparin, lipids, sugars, etc. [0043] In this regard, the skilled artisan will understand that the signals obtained from an immunoassay are a direct result of complexes formed between one or more antibodies and the target biomolecule (i.e., the analyte) and polypeptides containing the necessary epitope(s) to which the antibodies bind. While such assays may detect the full length biomarker and the assay result be expressed as a concentration of a biomarker of interest, the signal from the assay is actually a result of all such "immunoreactive" polypeptides present in the sample. Expression of biomarkers may also be determined by means other than immunoassays, including protein measurements (such as dot blots, western blots, chromatographic methods, mass spectrometry, etc.) and nucleic acid measurements (mRNA quatitation). This list is not meant to be limiting.

[0044] The term "positive going" marker as that term is used herein refer to a marker that is determined to be elevated in subjects suffering from a disease or condition, relative to subjects not suffering from that disease or condition. The term "negative going" marker as that term is used herein refer to a marker that is determined to be reduced in subjects suffering from a disease or condition, relative to subjects not suffering from that disease or condition.

[0045] The term "subject" as used herein refers to a human or non-human organism. Thus, the methods and compositions described herein are applicable to both human and veterinary disease. Further, while a subject is preferably a living organism, the invention described herein may be used in post-mortem analysis as well. Preferred subjects are humans, and most preferably "patients," which as used herein refers to living humans that are receiving medical care for a disease or condition. This includes persons with no defined illness who are being investigated for signs of pathology.

[0046] Preferably, an analyte is measured in a sample. Such a sample may be obtained from a subject, or may be obtained from biological materials intended to be provided to the subject. For example, a sample may be obtained from a kidney being evaluated for possible transplantation into a subject, and an analyte measurement used to evaluate the kidney for preexisting damage. Preferred samples are body fluid samples.

[0047] The term "body fluid sample" as used herein refers to a sample of bodily fluid obtained for the purpose of diagnosis, prognosis, classification or evaluation of a subject of interest, such as a patient or transplant donor. In certain embodiments, such a sample may be obtained for the purpose of determining the outcome of an ongoing condition or the effect of a treatment regimen on a condition. Preferred body fluid samples include blood, serum, plasma, cerebrospinal fluid, urine, saliva, sputum, and pleural effusions. In addition, one of skill in the art would realize that certain body fluid samples would be more readily analyzed following a fractionation or purification procedure, for example, separation of whole blood into serum or plasma components.

[0048] The term "diagnosis" as used herein refers to methods by which the skilled artisan can estimate and/or determine the probability ("a likelihood") of whether or not a patient is suffering from a given disease or condition. In the case of the present invention, "diagnosis" includes using the results of an assay, most preferably an immunoassay, for a kidney injury marker of the present invention, optionally together with other clinical characteristics, to arrive at a diagnosis (that is, the occurrence or nonoccurrence) of an acute renal injury or ARF for the subject from which a sample was obtained and assayed. That such a diagnosis is "determined" is not meant to imply that the diagnosis is 100% accurate. Many biomarkers are indicative of multiple conditions. The skilled clinician does not use biomarker results in an informational vacuum, but rather test results are used together with other clinical indicia to arrive at a diagnosis. Thus, a measured biomarker level on one side of a predetermined diagnostic threshold indicates a greater likelihood of the occurrence of disease in the subject relative to a measured level on the other side of the predetermined diagnostic threshold.

[0049] Similarly, a prognostic risk signals a probability ("a likelihood") that a given course or outcome will occur. A level or a change in level of a prognostic indicator, which in turn is associated with an increased probability of morbidity (e.g., worsening renal function, future ARF, or death) is referred to as being "indicative of an increased likelihood" of an adverse outcome in a patient.

[0050] Marker Assays

[0051] In general, immunoassays involve contacting a sample containing or suspected of containing a biomarker of interest with at least one antibody that specifically binds to the biomarker. A signal is then generated indicative of the presence or amount of complexes formed by the binding of polypeptides in the sample to the antibody. The signal is then related to the presence or amount of the biomarker in the sample. Numerous methods and devices are well known to the skilled artisan for the detection and analysis of biomarkers. See, e.g., U.S. Patents 6,143,576; 6, 113,855; 6,019,944; 5,985,579; 5,947,124; 5,939,272; 5,922,615; 5,885,527; 5,851 ,776; 5,824,799; 5,679,526; 5,525,524; and 5,480,792, and The Immunoassay Handbook, David Wild, ed. Stockton Press, New York, 1994, each of which is hereby incorporated by reference in its entirety, including all tables, figures and claims.

[0052] The assay devices and methods known in the art can utilize labeled molecules in various sandwich, competitive, or non-competitive assay formats, to generate a signal that is related to the presence or amount of the biomarker of interest. Suitable assay formats also include chromatographic, mass spectrographic, and protein "blotting" methods. Additionally, certain methods and devices, such as biosensors and optical immunoassays, may be employed to determine the presence or amount of analytes without the need for a labeled molecule. See, e.g., U.S. Patents 5,631,171 ; and 5,955,377, each of which is hereby incorporated by reference in its entirety, including all tables, figures and claims. One skilled in the art also recognizes that robotic instrumentation including but not limited to Beckman ACCESS®, Abbott AXSYM®, Roche

ELECSYS®, Dade Behring STRATUS® systems are among the immunoassay analyzers that are capable of performing immunoassays. But any suitable immunoassay may be utilized, for example, enzyme-linked immunoassays (ELISA), radioimmunoassays (RIAs), competitive binding assays, and the like.

[0053] Antibodies or other polypeptides may be immobilized onto a variety of solid supports for use in assays. Solid phases that may be used to immobilize specific binding members include include those developed and/or used as solid phases in solid phase binding assays. Examples of suitable solid phases include membrane filters, cellulose- based papers, beads (including polymeric, latex and paramagnetic particles), glass, silicon wafers, microparticles, nanoparticles, TentaGels, AgroGels, PEGA gels, SPOCC gels, and multiple-well plates. An assay strip could be prepared by coating the antibody or a plurality of antibodies in an array on solid support. This strip could then be dipped into the test sample and then processed quickly through washes and detection steps to generate a measurable signal, such as a colored spot. Antibodies or other polypeptides may be bound to specific zones of assay devices either by conjugating directly to an assay device surface, or by indirect binding. In an example of the later case, antibodies or other polypeptides may be immobilized on particles or other solid supports, and that solid support immobilized to the device surface. [0054] Biological assays require methods for detection, and one of the most common methods for quantitation of results is to conjugate a detectable label to a protein or nucleic acid that has affinity for one of the components in the biological system being studied. Detectable labels may include molecules that are themselves detectable (e.g., fluorescent moieties, electrochemical labels, metal chelates, etc.) as well as molecules that may be indirectly detected by production of a detectable reaction product (e.g., enzymes such as horseradish peroxidase, alkaline phosphatase, etc.) or by a specific binding molecule which itself may be detectable (e.g., biotin, digoxigenin, maltose, oligohistidine, 2,4- dintrobenzene, phenylarsenate, ssDNA, dsDNA, etc.).

[0055] Preparation of solid phases and detectable label conjugates often comprise the use of chemical cross-linkers. Cross-linking reagents contain at least two reactive groups, and are divided generally into homofunctional cross-linkers (containing identical reactive groups) and heterofunctional cross-linkers (containing non-identical reactive groups). Homobifunctional cross-linkers that couple through amines, sulfhydryls or react non- specifically are available from many commercial sources. Maleimides, alkyl and aryl halides, alpha-haloacyls and pyridyl disulfides are thiol reactive groups. Maleimides, alkyl and aryl halides, and alpha-haloacyls react with sulfhydryls to form thiol ether bonds, while pyridyl disulfides react with sulfhydryls to produce mixed disulfides. The pyridyl disulfide product is cleavable. Imidoesters are also very useful for protein-protein cross-links. A variety of heterobifunctional cross-linkers, each combining different attributes for successful conjugation, are commercially available.

[0056] In certain aspects, the present invention provides kits for the analysis of the described kidney injury markers. The kit comprises reagents for the analysis of at least one test sample which comprise at least one antibody that a kidney injury marker. The kit can also include devices and instructions for performing one or more of the diagnostic and/or prognostic correlations described herein. Preferred kits will comprise an antibody pair for performing a sandwich assay, or a labeled species for performing a competitive assay, for the analyte. Preferably, an antibody pair comprises a first antibody conjugated to a solid phase and a second antibody conjugated to a detectable label, wherein each of the first and second antibodies that bind a kidney injury marker. Most preferably each of the antibodies are monoclonal antibodies. The instructions for use of the kit and performing the correlations can be in the form of labeling, which refers to any written or recorded material that is attached to, or otherwise accompanies a kit at any time during its manufacture, transport, sale or use. For example, the term labeling encompasses advertising leaflets and brochures, packaging materials, instructions, audio or video cassettes, computer discs, as well as writing imprinted directly on kits.

[0057] Antibodies

[0058] The term "antibody" as used herein refers to a peptide or polypeptide derived from, modeled after or substantially encoded by an immunoglobulin gene or

immunoglobulin genes, or fragments thereof, capable of specifically binding an antigen or epitope. See, e.g. Fundamental Immunology, 3rd Edition, W.E. Paul, ed., Raven Press, N.Y. (1993); Wilson (1994; J. Immunol. Methods 175:267-273; Yarmush (1992) J. Biochem. Biophys. Methods 25:85-97. The term antibody includes antigen-binding portions, i.e., "antigen binding sites," (e.g., fragments, subsequences, complementarity determining regions (CDRs)) that retain capacity to bind antigen, including (i) a Fab fragment, a monovalent fragment consisting of the VL, VH, CL and CHI domains; (ii) a F(ab')2 fragment, a bivalent fragment comprising two Fab fragments linked by a disulfide bridge at the hinge region; (iii) a Fd fragment consisting of the VH and CHI domains; (iv) a Fv fragment consisting of the VL and VH domains of a single arm of an antibody, (v) a dAb fragment (Ward et al., (1989) Nature 341 :544-546), which consists of a VH domain; and (vi) an isolated complementarity determining region (CDR). Single chain antibodies are also included by reference in the term "antibody."

[0059] Antibodies used in the immunoassays described herein preferably specifically bind to a kidney injury marker of the present invention. The term "specifically binds" is not intended to indicate that an antibody binds exclusively to its intended target since, as noted above, an antibody binds to any polypeptide displaying the epitope(s) to which the antibody binds. Rather, an antibody "specifically binds" if its affinity for its intended target is about 5-fold greater when compared to its affinity for a non-target molecule which does not display the appropriate epitope(s). Preferably the affinity of the antibody will be at least about 5 fold, preferably 10 fold, more preferably 25-fold, even more preferably 50-fold, and most preferably 100-fold or more, greater for a target molecule than its affinity for a non-target molecule. In preferred embodiments, Preferred antibodies bind with affinities of at least about 10⁷ M^"1, and preferably between about 10⁸ M^"1 to about 10⁹ M^"1, about 10⁹ M^"1 to about 10¹⁰ M^"1, or about 10¹⁰ M^"1 to about 10¹² M^"1 . [0060] Affinity is calculated as ¾ = k_0ff/k_on (k_cff is the dissociation rate constant, K_on is the association rate constant and K_d is the equilibrium constant). Affinity can be determined at equilibrium by measuring the fraction bound (r) of labeled ligand at various concentrations (c). The data are graphed using the Scatchard equation: r/c = K(n-r): where r = moles of bound ligand/mole of receptor at equilibrium; c = free ligand concentration at equilibrium; K = equilibrium association constant; and n = number of ligand binding sites per receptor molecule. By graphical analysis, r/c is plotted on the Y-axis versus r on the X-axis, thus producing a Scatchard plot. Antibody affinity measurement by Scatchard analysis is well known in the art. See, e.g., van Erp et al., J. Immunoassay 12: 425-43, 1991 ; Nelson and Griswold, Comput. Methods Programs Biomed. 27: 65-8, 1988.

[0061] The term "epitope" refers to an antigenic determinant capable of specific binding to an antibody. Epitopes usually consist of chemically active surface groupings of molecules such as amino acids or sugar side chains and usually have specific three dimensional structural characteristics, as well as specific charge characteristics.

Conformational and nonconformational epitopes are distinguished in that the binding to the former but not the latter is lost in the presence of denaturing solvents.

[0062] Numerous publications discuss the use of phage display technology to produce and screen libraries of polypeptides for binding to a selected analyte. See, e.g, Cwirla et al, Proc. Natl. Acad. Sci. USA 87, 6378-82, 1990; Devlin et al, Science 249, 404-6, 1990, Scott and Smith, Science 249, 386-88, 1990; and Ladner et al, U.S. Pat. No.

5,571,698. A basic concept of phage display methods is the establishment of a physical association between DNA encoding a polypeptide to be screened and the polypeptide. This physical association is provided by the phage particle, which displays a polypeptide as part of a capsid enclosing the phage genome which encodes the polypeptide. The establishment of a physical association between polypeptides and their genetic material allows simultaneous mass screening of very large numbers of phage bearing different polypeptides. Phage displaying a polypeptide with affinity to a target bind to the target and these phage are enriched by affinity screening to the target. The identity of polypeptides displayed from these phage can be determined from their respective genomes. Using these methods a polypeptide identified as having a binding affinity for a desired target can then be synthesized in bulk by conventional means. See, e.g., U.S. Patent No. 6,057,098, which is hereby incorporated in its entirety, including all tables, figures, and claims. [0063] The antibodies that are generated by these methods may then be selected by first screening for affinity and specificity with the purified polypeptide of interest and, if required, comparing the results to the affinity and specificity of the antibodies with polypeptides that are desired to be excluded from binding. The screening procedure can involve immobilization of the purified polypeptides in separate wells of microtiter plates. The solution containing a potential antibody or groups of antibodies is then placed into the respective microtiter wells and incubated for about 30 min to 2 h. The microtiter wells are then washed and a labeled secondary antibody (for example, an anti-mouse antibody conjugated to alkaline phosphatase if the raised antibodies are mouse antibodies) is added to the wells and incubated for about 30 min and then washed. Substrate is added to the wells and a color reaction will appear where antibody to the immobilized polypeptide(s) are present.

[0064] The antibodies so identified may then be further analyzed for affinity and specificity in the assay design selected. In the development of immunoassays for a target protein, the purified target protein acts as a standard with which to judge the sensitivity and specificity of the immunoassay using the antibodies that have been selected. Because the binding affinity of various antibodies may differ; certain antibody pairs (e.g., in sandwich assays) may interfere with one another sterically, etc., assay performance of an antibody may be a more important measure than absolute affinity and specificity of an antibody.

[0065] While the present application describes antibody-based binding assays in detail, alternatives to antibodies as binding species in assays are well known in the art. These include receptors for a particular target, aptamers, etc. Aptamers are oligonucleic acid or peptide molecules that bind to a specific target molecule. Aptamers are usually created by selecting them from a large random sequence pool, but natural aptamers also exist. High-affinity aptamers containing modified nucleotides conferring improved characteristics on the ligand, such as improved in vivo stability or improved delivery characteristics. Examples of such modifications include chemical substitutions at the ribose and/or phosphate and/or base positions, and may include amino acid side chain functionalities.

[0066] Assay Correlations [0067] The term "correlating" as used herein in reference to the use of biomarkers refers to comparing the presence or amount of the biomarker(s) in a patient to its presence or amount in persons known to suffer from, or known to be at risk of, a given condition; or in persons known to be free of a given condition. Often, this takes the form of comparing an assay result in the form of a biomarker concentration to a predetermined threshold selected to be indicative of the occurrence or nonoccurrence of a disease or the likelihood of some future outcome.

[0068] Selecting a diagnostic threshold involves, among other things, consideration of the probability of disease, distribution of true and false diagnoses at different test thresholds, and estimates of the consequences of treatment (or a failure to treat) based on the diagnosis. For example, when considering administering a specific therapy which is highly efficacious and has a low level of risk, few tests are needed because clinicians can accept substantial diagnostic uncertainty. On the other hand, in situations where treatment options are less effective and more risky, clinicians often need a higher degree of diagnostic certainty. Thus, cost/benefit analysis is involved in selecting a diagnostic threshold.

[0069] Suitable thresholds may be determined in a variety of ways. For example, one recommended diagnostic threshold for the diagnosis of acute myocardial infarction using cardiac troponin is the 97.5th percentile of the concentration seen in a normal population. Another method may be to look at serial samples from the same patient, where a prior "baseline" result is used to monitor for temporal changes in a biomarker level.

[0070] Population studies may also be used to select a decision threshold. Reciever Operating Characteristic ("ROC") arose from the field of signal dectection therory developed during World War II for the analysis of radar images, and ROC analysis is often used to select a threshold able to best distinguish a "diseased" subpopulation from a "nondiseased" subpopulation. A false positive in this case occurs when the person tests positive, but actually does not have the disease. A false negative, on the other hand, occurs when the person tests negative, suggesting they are healthy, when they actually do have the disease. To draw a ROC curve, the true positive rate (TPR) and false positive rate (FPR) are determined as the decision threshold is varied continuously. Since TPR is equivalent with sensitivity and FPR is equal to 1 - specificity, the ROC graph is sometimes called the sensitivity vs (1 - specificity) plot. A perfect test will have an area under the ROC curve of 1.0; a random test will have an area of 0.5. A threshold is selected to provide an acceptable level of specificity and sensitivity.

[0071] In this context, "diseased" is meant to refer to a population having one characteristic (the presence of a disease or condition or the occurrence of some outcome) and "nondiseased" is meant to refer to a population lacking the characteristic. While a single decision threshold is the simplest application of such a method, multiple decision thresholds may be used. For example, below a first threshold, the absence of disease may be assigned with relatively high confidence, and above a second threshold the presence of disease may also be assigned with relatively high confidence. Between the two thresholds may be considered indeterminate. This is meant to be exemplary in nature only.

[0072] In addition to threshold comparisons, other methods for correlating assay results to a patient classification (occurrence or nonoccurrence of disease, likelihood of an outcome, etc.) include decision trees, rule sets, Bayesian methods, and neural network methods. These methods can produce probability values representing the degree to which a subject belongs to one classification out of a plurality of classifications.

[0073] Measures of test accuracy may be obtained as described in Fischer et al, Intensive Care Med. 29: 1043-51 , 2003, and used to determine the effectiveness of a given biomarker. These measures include sensitivity and specificity, predictive values, likelihood ratios, diagnostic odds ratios, and ROC curve areas. The area under the curve ("AUC") of a ROC plot is equal to the probability that a classifier will rank a randomly chosen positive instance higher than a randomly chosen negative one. The area under the ROC curve may be thought of as equivalent to the Mann-Whitney U test, which tests for the median difference between scores obtained in the two groups considered if the groups are of continuous data, or to the Wilcoxon test of ranks.

[0074] As discussed above, suitable tests may exhibit one or more of the following results on these various measures: a specificity of greater than 0.5, preferably at least 0.6, more preferably at least 0.7, still more preferably at least 0.8, even more preferably at least 0.9 and most preferably at least 0.95, with a corresponding sensitivity greater than 0.2, preferably greater than 0.3, more preferably greater than 0.4, still more preferably at least 0.5, even more preferably 0.6, yet more preferably greater than 0.7, still more preferably greater than 0.8, more preferably greater than 0.9, and most preferably greater than 0.95; a sensitivity of greater than 0.5, preferably at least 0.6, more preferably at least 0.7, still more preferably at least 0.8, even more preferably at least 0.9 and most preferably at least 0.95, with a corresponding specificity greater than 0.2, preferably greater than 0.3, more preferably greater than 0.4, still more preferably at least 0.5, even more preferably 0.6, yet more preferably greater than 0.7, still more preferably greater than 0.8, more preferably greater than 0.9, and most preferably greater than 0.95; at least 75% sensitivity, combined with at least 75% specificity; a ROC curve area of greater than

0.5, preferably at least 0.6, more preferably 0.7, still more preferably at least 0.8, even more preferably at least 0.9, and most preferably at least 0.95; an odds ratio different from

1, preferably at least about 2 or more or about 0.5 or less, more preferably at least about 3 or more or about 0.33 or less, still more preferably at least about 4 or more or about 0.25 or less, even more preferably at least about 5 or more or about 0.2 or less, and most preferably at least about 10 or more or about 0.1 or less; a positive likelihood ratio (calculated as sensitivity/(l- specificity)) of greater than 1, at least 2, more preferably at least 3, still more preferably at least 5, and most preferably at least 10; and or a negative likelihood ratio (calculated as (l-sensitivity)/specificity) of less than 1, less than or equal to 0.5, more preferably less than or equal to 0.3, and most preferably less than or equal to 0.1

[0075] Additional clinical indicia may be combined with the kidney injury marker assay result(s) of the present invention. These include other biomarkers related to renal status. Examples include the following, which recite the common biomarker name, followed by the Swiss-Prot entry number for that biomarker or its parent: Actin (P68133); Adenosine deaminase binding protein (DPP4, P27487); Alpha-l-acid glycoprotein 1 (P02763); Alpha- 1 -microglobulin (P02760); Albumin (P02768); Angiotensinogenase (Renin, P00797); Annexin A2 (P07355); Beta-glucuronidase (P08236); B-2- microglobulin (P61679); Beta-galactosidase (P16278); BMP-7 (P18075); Brain natriuretic peptide (proBNP, BNP-32, NTproBNP; PI 6860); Calcium-binding protein Beta (SlOO-beta, P04271); Carbonic anhydrase (Q16790); Casein Kinase 2 (P68400); Ceruloplasmin (P00450); Clusterin (P10909); Complement C3 (P01024); Cysteine-rich protein (CYR61, 000622); Cytochrome C (P99999); Epidermal growth factor (EOF, P01133); Endothelin-1 (P05305); Exosomal Fetuin-A (P02765); Fatty acid-binding protein, heart (FABP3, P05413); Fatty acid-binding protein, liver (P07148); Ferritin (light chain, P02793; heavy chain P02794); Fructose- 1,6-biphosphatase (P09467); GRO-alpha (CXCL1, (P09341); Growth Hormone (P01241); Hepatocyte growth factor (P14210); Insulin-like growth factor I (P01343); Immunoglobulin G; Immunoglobulin Light Chains (Kappa and Lambda); Interferon gamma (P01308); Lysozyme (P61626); Interleukin- lalpha (P01583); Interleukin-2 (P60568); Interleukin-4 (P60568); Interleukin-9 (P15248); Interleukin-12p40 (P29460); Interleukin-13 (P35225); Interleukin-16 (Q14005); LI cell adhesion molecule (P32004); Lactate dehydrogenase (P00338); Leucine Aminopeptidase (P28838); Meprin A-alpha subunit (Q16819); Meprin A-beta subunit (Q16820); Midkine (P21741); MIP2-alpha (CXCL2, P19875); MMP-2 (P08253); MMP-9 (P14780); Netrin-1 (095631); Neutral endopeptidase (P08473); Osteopontin (P10451); Renal papillary antigen 1 (RPA1); Renal papillary antigen 2 (RPA2); Retinol binding protein (P09455); Ribonuclease; SlOO calcium-binding protein A6 (P06703); Serum Amyloid P Component (P02743); Sodium/Hydrogen exchanger isoform (NHE3, P48764); Spermidine/spermine Nl-acetyltransferase (P21673); TGF-Betal (P01137); Transferrin (P02787); Trefoil factor 3 (TFF3, Q07654); Toll-Like protein 4 (000206); Total protein; Tubulointerstitial nephritis antigen (Q9UJW2); Uromodulin (Tamm-Horsfall protein, P07911).

[0076] For purposes of risk stratification, Adiponectin (Q15848); Alkaline phosphatase (P05186); Aminopeptidase N (P15144); CalbindinD28k (P05937); Cystatin C (P01034); 8 subunit of FIFO ATPase (P03928); Gamma-glutamyltransferase (P19440); GSTa (alpha-glutathione-S-transferase, P08263); GSTpi (Glutathione-S-transferase P; GST class-pi; P09211); IGFBP-1 (P08833); IGFBP-2 (P18065); IGFBP-6 (P24592); Integral membrane protein 1 (Itml, P46977); Interleukin-6 (P05231); Interleukin-8 (P10145); Interleukin-18 (Q14116); IP- 10 (10 kDa interferon-gamma-induced protein, P02778); IRPR (IFRD1, 000458); Isovaleryl-CoA dehydrogenase (IVD, P26440); I- TAC/CXCL11 (014625); Keratin 19 (P08727); Kim-1 (Hepatitis A virus cellular receptor 1, 043656); L-arginine:glycine amidinotransferase (P50440); Leptin (P41159); Lipocalin2 (NGAL, P80188); MCP-1 (P13500); MIG (Gamma-interferon-induced monokine Q07325); MIP-la (P10147); MIP-3a (P78556); MIP-lbeta (P13236); MIP-ld (Q16663); NAG (N-acetyl-beta-D-glucosaminidase, P54802); Organic ion transporter (OCT2, 015244); Osteoprotegerin (014788); P8 protein (060356); Plasminogen activator inhibitor 1 (PAI-1, P05121); ProANP(l-98) (P01160); Protein phosphatase 1- beta (PPI-beta, P62140); Rab GDI-beta (P50395); Renal kallikrein (Q86U61 ); RTl.B-1 (alpha) chain of the integral membrane protein (Q5Y7A8); Soluble tumor necrosis factor receptor superfamily member 1A (sTNFR-I, P19438); Soluble tumor necrosis factor receptor superfamily member IB (sTNFR-II, P20333); Tissue inhibitor of metalloproteinases 3 (TIMP-3, P35625); uPAR (Q03405) may be combined with the kidney injury marker assay result(s) of the present invention.

[0077] Other clinical indicia which may be combined with the kidney injury marker assay result(s) of the present invention includes demographic information (e.g., weight, sex, age, race), medical history (e.g., family history, type of surgery, pre-existing disease such as aneurism, congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, or sepsis, type of toxin exposure such as NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin), clinical variables (e.g., blood pressure, temperature, respiration rate), risk scores (APACHE score, PREDICT score, TIMI Risk Score for UA/NSTEMI, Framingham Risk Score), a urine total protein measurement, a glomerular filtration rate, an estimated glomerular filtration rate, a urine production rate, a serum or plasma creatinine concentration, a renal papillary antigen 1 (RPA1)

measurement; a renal papillary antigen 2 (RPA2) measurement; a urine creatinine concentration, a fractional excretion of sodium, a urine sodium concentration, a urine creatinine to serum or plasma creatinine ratio, a urine specific gravity, a urine osmolality, a urine urea nitrogen to plasma urea nitrogen ratio, a plasma BUN to creatnine ratio, and/or a renal failure index calculated as urine sodium / (urine creatinine / plasma creatinine). Other measures of renal function which may be combined with the kidney injury marker assay result(s) are described hereinafter and in Harrison's Principles of Internal Medicine, 17^th Ed., McGraw Hill, New York, pages 1741- 1830, and Current Medical Diagnosis & Treatment 2008, 47^th Ed, McGraw Hill, New York, pages 785-815, each of which are hereby incorporated by reference in their entirety.

[0078] Combining assay results/clinical indicia in this manner can comprise the use of multivariate logistical regression, loglinear modeling, neural network analysis, n-of-m analysis, decision tree analysis, etc. This list is not meant to be limiting.

[0079] Diagnosis of Acute Renal Failure

[0080] As noted above, the terms "acute renal (or kidney) injury" and "acute renal (or kidney) failure" as used herein are defined in part in terms of changes in serum creatinine from a baseline value. Most definitions of ARF have common elements, including the use of serum creatinine and, often, urine output. Patients may present with renal dysfunction without an available baseline measure of renal function for use in this comparison. In such an event, one may estimate a baseline serum creatinine value by assuming the patient initially had a normal GFR. Glomerular filtration rate (GFR) is the volume of fluid filtered from the renal (kidney) glomerular capillaries into the Bowman's capsule per unit time. Glomerular filtration rate (GFR) can be calculated by measuring any chemical that has a steady level in the blood, and is freely filtered but neither reabsorbed nor secreted by the kidneys. GFR is typically expressed in units of ml/min:

Urine Concentration x Urine Flow

GFR

P tsrn a Co ncentr alio n

[0081] By normalizing the GFR to the body surface area, a GFR of approximately 75-100 ml/min per 1.73 m² can be assumed. The rate therefore measured is the quantity of the substance in the urine that originated from a calculable volume of blood.

[0082] There are several different techniques used to calculate or estimate the glomerular filtration rate (GFR or eGFR). In clinical practice, however, creatinine clearance is used to measure GFR. Creatinine is produced naturally by the body

(creatinine is a metabolite of creatine, which is found in muscle). It is freely filtered by the glomerulus, but also actively secreted by the renal tubules in very small amounts such that creatinine clearance overestimates actual GFR by 10-20%. This margin of error is acceptable considering the ease with which creatinine clearance is measured.

[0083] Creatinine clearance (CCr) can be calculated if values for creatinine's urine concentration (Uc_r)_> urine flow rate (V), and creatinine's plasma concentration (Ρ&) are known. Since the product of urine concentration and urine flow rate yields creatinine's excretion rate, creatinine clearance is also said to be its excretion rate (UQ-XV) divided by its lasma concentration. This is commonly represented mathematically as:

Commonly a 24 hour urine collection is undertaken, from empty-bladder one morning to the contents of the bladder the following morning, with a comparative blood test then taken: 24-h.oui νοΐτοπΐ

Pa- x 24 x Qdmins

To allow comparison of results between people of different sizes, the CCr is often corrected for the body surface area (BSA) and expressed compared to the average sized man as ml/min/1.73 m2. While most adults have a BSA that approaches 1.7 (1.6-1.9), extremely obese or slim patients should have their CCr corrected for their actual BSA:

[0084] The accuracy of a creatinine clearance measurement (even when collection is complete) is limited because as glomerular filtration rate (GFR) falls creatinine secretion is increased, and thus the rise in serum creatinine is less. Thus, creatinine excretion is much greater than the filtered load, resulting in a potentially large overestimation of the GFR (as much as a twofold difference). However, for clinical purposes it is important to determine whether renal function is stable or getting worse or better. This is often determined by monitoring serum creatinine alone. Like creatinine clearance, the serum creatinine will not be an accurate reflection of GFR in the non-steady-state condition of ARF. Nonetheless, the degree to which serum creatinine changes from baseline will reflect the change in GFR. Serum creatinine is readily and easily measured and it is specific for renal function.

[0085] For purposes of determining urine output on a mL/kg/hr basis, hourly urine collection and measurement is adequate. In the case where, for example, only a cumulative 24-h output was available and no patient weights are provided, minor modifications of the RIFLE urine output criteria have been described. For example, Bagshaw et ah, Nephrol. Dial. Transplant. 23: 1203-1210, 2008, assumes an average patient weight of 70 kg, and patients are assigned a RIFLE classification based on the following: <35 mL/h (Risk), <21 mL/h (Injury) or <4 mL/h (Failure).

[0086] Selecting a Treatment Regimen

[0087] Once a diagnosis is obtained, the clinician can readily select a treatment regimen that is compatible with the diagnosis, such as initiating renal replacement therapy, withdrawing delivery of compounds that are known to be damaging to the kidney, kidney transplantation, delaying or avoiding procedures that are known to be damaging to the kidney, modifying diuretic administration, initiating goal directed therapy, etc. The skilled artisan is aware of appropriate treatments for numerous diseases discussed in relation to the methods of diagnosis described herein. See, e.g., Merck Manual of Diagnosis and Therapy, 17th Ed. Merck Research Laboratories, Whitehouse Station, NJ, 1999. In addition, since the methods and compositions described herein provide prognostic information, the markers of the present invention may be used to monitor a course of treatment. For example, improved or worsened prognostic state may indicate that a particular treatment is or is not efficacious.

[0088] One skilled in the art readily appreciates that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The examples provided herein are representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention.

[0089] Example 1: Contrast-induced nephropathy sample collection

[0090] The objective of this sample collection study is to collect samples of plasma and urine and clinical data from patients before and after receiving intravascular contrast media. Approximately 250 adults undergoing radiographic/angiographic procedures involving intravascular administration of iodinated contrast media are enrolled. To be enrolled in the study, each patient must meet all of the following inclusion criteria and none of the following exclusion criteria:

Inclusion Criteria

males and females 18 years of age or older;

undergoing a radiographic / angiographic procedure (such as a CT scan or coronary intervention) involving the intravascular administration of contrast media;

expected to be hospitalized for at least 48 hours after contrast administration.

able and willing to provide written informed consent for study participation and to comply with all study procedures.

Exclusion Criteria

renal transplant recipients;

acutely worsening renal function prior to the contrast procedure; already receiving dialysis (either acute or chronic) or in imminent need of dialysis at enrollment;

expected to undergo a major surgical procedure (such as involving cardiopulmonary bypass) or an additional imaging procedure with contrast media with significant risk for further renal insult within the 48 hrs following contrast administration;

participation in an interventional clinical study with an experimental therapy within the previous 30 days;

known infection with human immunodeficiency virus (HIV) or a hepatitis virus.

[0091] Immediately prior to the first contrast administration (and after any pre- procedure hydration), an EDTA anti-coagulated blood sample (10 mL) and a urine sample (10 mL) are collected from each patient. Blood and urine samples are then collected at 4 (±0.5), 8 (±1), 24 (±2) 48 (±2), and 72 (±2) hrs following the last administration of contrast media during the index contrast procedure. Blood is collected via direct venipuncture or via other available venous access, such as an existing femoral sheath, central venous line, peripheral intravenous line or hep-lock. These study blood samples are processed to plasma at the clinical site, frozen and shipped to Astute Medical, Inc., San Diego, CA. The study urine samples are frozen and shipped to Astute Medical, Inc.

[0092] Serum creatinine is assessed at the site immediately prior to the first contrast administration (after any pre-procedure hydration) and at 4 (±0.5), 8 (±1), 24 (±2) and 48 (±2) ), and 72 (±2) hours following the last administration of contrast (ideally at the same time as the study samples are obtained). In addition, each patient's status is evaluated through day 30 with regard to additional serum and urine creatinine measurements, a need for dialysis, hospitalization status, and adverse clinical outcomes (including mortality).

[0093] Prior to contrast administration, each patient is assigned a risk based on the following assessment: systolic blood pressure <80 mm Hg = 5 points; intra-arterial balloon pump = 5 points; congestive heart failure (Class III-IV or history of pulmonary edema) = 5 points; age >75 yrs = 4 points; hematocrit level <39 for men, <35 for women = 3 points; diabetes = 3 points; contrast media volume = 1 point for each 100 mL; serum creatinine level >1.5 g/dL = 4 points OR estimated GFR 40-60 mL/min/1.73 m² = 2 points, 20-40 mL/min/1.73 m² = 4 points, < 20 mL/min/1.73 m² = 6 points. The risks assigned are as follows: risk for CIN and dialysis: 5 or less total points = risk of CIN - 7.5%, risk of dialysis - 0.04%; 6-10 total points = risk of CIN - 14%, risk of dialysis - 0.12%; 11-16 total points = risk of CIN - 26.1%, risk of dialysis - 1.09%; >16 total points = risk of CIN - 57.3%, risk of dialysis - 12.8%.

[0094] Example 2: Cardiac surgery sample collection

[0095] The objective of this sample collection study is to collect samples of plasma and urine and clinical data from patients before and after undergoing cardiovascular surgery, a procedure known to be potentially damaging to kidney function.

Approximately 900 adults undergoing such surgery are enrolled. To be enrolled in the study, each patient must meet all of the following inclusion criteria and none of the following exclusion criteria:

Inclusion Criteria

males and females 18 years of age or older;

undergoing cardiovascular surgery;

Toronto/Ottawa Predictive Risk Index for Renal Replacement risk score of at least 2 (Wijeysundera et al, JAMA 297: 1801-9, 2007); and

able and willing to provide written informed consent for study participation and to comply with all study procedures.

Exclusion Criteria

known pregnancy;

previous renal transplantation;

acutely worsening renal function prior to enrollment (e.g., any category of

RIFLE criteria);

already receiving dialysis (either acute or chronic) or in imminent need of dialysis at enrollment;

currently enrolled in another clinical study or expected to be enrolled in another clinical study within 7 days of cardiac surgery that involves drug infusion or a therapeutic intervention for AKI;

known infection with human immunodeficiency virus (HIV) or a hepatitis virus. [0096] Within 3 hours prior to the first incision (and after any pre-procedure hydration), an EDTA anti-coagulated blood sample (10 mL), whole blood (3 mL), and a urine sample (35 mL) are collected from each patient. Blood and urine samples are then collected at 3 (±0.5), 6 (±0.5), 12 (±1), 24 (±2) and 48 (±2) hrs following the procedure and then daily on days 3 through 7 if the subject remains in the hospital. Blood is collected via direct venipuncture or via other available venous access, such as an existing femoral sheath, central venous line, peripheral intravenous line or hep-lock. These study blood samples are frozen and shipped to Astute Medical, Inc., San Diego, CA. The study urine samples are frozen and shipped to Astute Medical, Inc.

[0097] Example 3: Acutely ill subject sample collection

[0098] The objective of this study is to collect samples from acutely ill patients. Approximately 1900 adults expected to be in the ICU for at least 48 hours will be enrolled. To be enrolled in the study, each patient must meet all of the following inclusion criteria and none of the following exclusion criteria:

Inclusion Criteria

males and females 18 years of age or older;

Study population 1 : approximately 300 patients that have at least one of:

shock (SBP < 90 mmHg and/or need for vasopressor support to maintain MAP > 60 mmHg and/or documented drop in SBP of at least 40 mmHg); and

sepsis;

Study population 2: approximately 300 patients that have at least one of:

IV antibiotics ordered in computerized physician order entry (CPOE) within 24 hours of enrollment;

contrast media exposure within 24 hours of enrollment;

increased Intra-Abdominal Pressure with acute decompensated heart failure; and severe trauma as the primary reason for ICU admission and likely to be hospitalized in the ICU for 48 hours after enrollment;

Study population 3: approximately 300 patients expected to be hospitalized through acute care setting (ICU or ED) with a known risk factor for acute renal injury (e.g. sepsis, hypotension/shock (Shock = systolic BP < 90 mmHg and/or the need for vasopressor support to maintain a MAP > 60 mmHg and/or a documented drop in SBP > 40 mmHg), major trauma, hemorrhage, or major surgery); and/or expected to be hospitalized to the ICU for at least 24 hours after enrollment;

Study population 4: approximately 1000 patients that are 21 years of age or older, within 24 hours of being admitted into the ICU, expected to have an indwelling urinary catheter for at least 48 hours after enrollment, and have at least one of the following acute conditions within 24 hours prior to enrollment:

(i) respiratory SOFA score of > 2 (Pa02/Fi02 <300), (ii) cardiovascular SOFA score of > 1 (MAP < 70 mm Hg and/or any vasopressor required).

Exclusion Criteria

known pregnancy;

institutionalized individuals;

previous renal transplantation;

known acutely worsening renal function prior to enrollment (e.g., any category of RIFLE criteria);

received dialysis (either acute or chronic) within 5 days prior to enrollment or in imminent need of dialysis at the time of enrollment;

known infection with human immunodeficiency virus (HIV) or a hepatitis virus;

meets any of the following:

(i) active bleeding with an anticipated need for > 4 units PRBC in a day;

(ii) hemoglobin < 7 g/dL;

(iii) any other condition that in the physician's opinion would contraindicate drawing serial blood samples for clinical study purposes;

meets only the SBP < 90 mmHg inclusion criterion set forth above, and does not have shock in the attending physician's or principal investigator's opinion;

[0099] After obtaining informed consent, an EDTA anti-coagulated blood sample (10 mL), a serum blood sample (0-3 mL) and a urine sample (25-50 mL) are collected from each patient. Blood and urine samples are then collected at 4 (+ 0.5) and 8 (+ 1) hours after contrast administration (if applicable); at 12 (± 1), 24 (± 2), 36 (± 2), 48 (± 2), 60 (± 2), 72 (± 2), and 84 (± 2) hours after enrollment, and thereafter daily up to day 7 or day 14 while the subject is hospitalized. Blood is collected via direct venipuncture or via other available venous access, such as an existing femoral sheath, central venous line, peripheral intravenous line or hep-lock. These study blood samples are processed to plasma and serum at the clinical site, frozen and shipped to Astute Medical, Inc., San Diego, CA. The study urine samples are frozen and shipped to Astute Medical, Inc.

[00100] Example 4. Immunoassay format

[0100] Analytes are measured using standard sandwich enzyme immunoassay techniques. A first antibody which binds the analyte was immobilized on a nitrocellulose test strip. A fluorescently-conjugated second antibody which binds the analyte was added to the test sample, and the mixtire allowed to traverse the nitrocellulose strip in a lateral flow fashion, thereby forming sandwich complexes with the analyte (if present) and the first antibody. Fluorescence in proportion to the amount of analyte present in the sample was detected using a fluorometer. =An analyte concentration was assigned to the test sample by comparison to a standard curve determined from the analyte standards.

[0101] Units for the concentrations reported in the following data tables are as follows: Insulin- like growth factor-binding protein 7 - ng/mL, Metalloproteinase inhibitor 2 - ng/mL.

[0102] In the case of those kidney injury markers which are membrane proteins as described herein, the assays used in these examples detect soluble forms thereof.

[0103] Example 5. Apparently Healthy Donor and Chronic Disease Patient

Samples

[0104] Human urine samples from donors with no known chronic or acute disease ("Apparently Healthy Donors") were purchased from two vendors (Golden West Biologicals, Inc., 27625 Commerce Center Dr., Temecula, CA 92590 and Virginia Medical Research, Inc., 915 First Colonial Rd., Virginia Beach, VA 23454). The urine samples were shipped and stored frozen at less than -20° C. The vendors supplied demographic information for the individual donors including gender, race (Black /White), smoking status and age.

[0105] Human urine samples from donors with various chronic diseases ("Chronic Disease Patients") including congestive heart failure, coronary artery disease, chronic kidney disease, chronic obstructive pulmonary disease, diabetes mellitus and

hypertension were purchased from Virginia Medical Research, Inc., 915 First Colonial Rd., Virginia Beach, VA 23454. The urine samples were shipped and stored frozen at less than -20 degrees centigrade. The vendor provided a case report form for each individual donor with age, gender, race (Black/White), smoking status and alcohol use, height, weight, chronic disease(s) diagnosis, current medications and previous surgeries.

[0106] Example 6. Use of Kidney Injury Markers for evaluating renal status in patients

[0107] Patients from the intensive care unit (ICU) were enrolled in the following study. Each patient was classified by kidney status as non-injury (0), risk of injury (R), injury (I), and failure (F) according to the maximum stage reached within 7 days of enrollment as determined by the RIFLE criteria. EDTA anti-coagulated blood samples (10 mL), serum blood samples (3 mL), and urine samples (25-30 mL) were collected from each patient at enrollment, 4 (+ 0.5) and 8 (+ 1) hours after contrast administration (if applicable); at 12 (+ 1), 24 (+ 2), 36 (+ 2), 48 (+ 2), 60 (± 2), 72 (± 2), and 84 (± 2) hours after enrollment hours after enrollment, and thereafter daily up to day 7 to day 14 while the subject is hospitalized. Insulin-like growth factor-binding protein 7 and

Metalloproteinase inhibitor 2 were each measured by the NephroCheck Test (Astute Medical, Inc., San Diego, CA) in the urine samples. Serum samples were shipped to an independent laboratory for creatinine analysis using methods based on the Jaffe reaction. Serum creatinine is reported in units of mg/dL in the tables below. Urine flow and patient weight were recorded at the clinical sites. Weight adjusted urine output is reported in units of mL/kg/h for the time of sample collection.

[0108] Two cohorts were defined to represent a "diseased" and a "normal" population. While these terms are used for convenience, "diseased" and "normal" simply represent two cohorts for comparison (say RIFLE 0 vs RIFLE R, I and F; RIFLE 0 vs RIFLE R; RIFLE 0 and R vs RIFLE I and F; etc.). The time "prior max stage" represents the time at which a sample is collected, relative to the time a particular patient reaches the lowest disease stage as defined for that cohort, binned into three groups which are +/- 12 hours. For example, "24 hr prior" which uses 0 vs R, I, F as the two cohorts would mean 24 hr (+/- 12 hours) prior to reaching stage R (or I if no sample at R, or F if no sample at R or I). [0109] A receiver operating characteristic (ROC) curve was generated for each biomarker measured and the area under each ROC curve (AUC) is determined. Patients in Cohort 2 were also separated according to the reason for adjudication to cohort 2 as being based on serum creatinine measurements (sCr), being based on urine output (UO), or being based on either serum creatinine measurements or urine output. Using the same example discussed above (0 vs R, I, F), for those patients adjudicated to stage R, I, or F on the basis of serum creatinine measurements alone, the stage 0 cohort may include patients adjudicated to stage R, I, or F on the basis of urine output; for those patients adjudicated to stage R, I, or F on the basis of urine output alone, the stage 0 cohort may include patients adjudicated to stage R, I, or F on the basis of serum creatinine measurements; and for those patients adjudicated to stage R, I, or F on the basis of serum creatinine measurements or urine output, the stage 0 cohort contains only patients in stage 0 for both serum creatinine measurements and urine output. Also, in the data for patients adjudicated on the basis of serum creatinine measurements or urine output, the adjudication method which yielded the most severe RIFLE stage is used.

[0110] The ability to distinguish cohort 1 from Cohort 2 was determined using ROC analysis. SE is the standard error of the AUC, n is the number of sample or individual patients ("pts," as indicated). Standard errors are calculated as described in Hanley, J. A., and McNeil, B.J., The meaning and use of the area under a receiver operating

characteristic (ROC) curve. Radiology (1982) 143: 29-36; p values are calculated with a two-tailed Z-test. An AUC < 0.5 is indicative of a negative going marker for the comparison, and an AUC > 0.5 is indicative of a positive going marker for the comparison.

[0111] Various threshold (or "cutoff) concentrations were selected, and the associated sensitivity and specificity for distinguishing cohort 1 from cohort 2 are determined. OR is the odds ratio calculated for the particular cutoff concentration, and 95% CI is the confidence interval for the odds ratio.

[0112] Table 1: Comparison of marker levels in samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0) and in samples collected from subjects at 0, 24 hours, and 48 hours prior to reaching stage R, I or F in Cohort 2. Insulinlike growth factor-binding protein 7 and Metalloproteinase inhibitor 2 were measured in urine. Insulin-like growth factor-binding protein 7

Metalloproteinase inhibitor 2

Weight Adjusted Urine Output

Insulin-like growth factor-binding protein 7 / (Weight Adjusted Urine Output)

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 59.4 298 59.4 106 59.4 92.9

Average 52600 397000 52600 214000 52600 172000

Stdev 638000 2620000 638000 1960000 638000 1250000 p(t-test) 1.7E-7 0.0078 0.077

Min 0.929 1.89 0.929 2.22 0.929 3.01

Max 1.26E7 2.66E7 1.26E7 2.15E7 1.26E7 9700000 n (Samp) 2069 408 2069 223 2069 107 n (Patient) 273 408 273 223 273 107 sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 87.7 259 87.7 154 87.7 127

Average 79400 420000 79400 767000 79400 497000

Stdev 922000 3270000 922000 4670000 922000 2730000 p(t-test) 2.5E-4 1.6E-8 9.2E-4

Min 0.929 2.58 0.929 2.22 0.929 4.41

Max 2.49E7 2.88E7 2.49E7 3.83E7 2.49E7 1.67E7 n (Samp) 3862 145 3862 93 3862 61 n (Patient) 515 145 515 93 515 61

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Sens 4 79% 58% 85% 48% 46% 51% 42% 41% 43% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 152 248 154 152 248 154 152 248 154 Sens 5 71% 50% 78% 38% 30% 39% 35% 25% 32% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 244 412 248 244 412 248 244 412 248 Sens 6 58% 28% 65% 21% 19% 25% 16% 15% 16% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.3 1.7 1.1 1.8 1.1 1.6 0.86 1.8 0.86 p Value 0.34 0.13 0.73 0.023 0.86 0.059 0.63 0.20 0.63 95% CI of 0.76 0.85 0.57 1.1 0.52 0.98 0.46 0.73 0.46 OR Quart2 2.3 3.4 2.2 2.9 2.2 2.7 1.6 4.2 1.6

OR Quart 3 3.5 2.8 3.6 2.3 1.8 2.5 1.1 2.4 0.95 p Value 1.8E-7 0.0020 8.1E-6 6.4E-4 0.065 2.0E-4 0.76 0.039 0.88 95% CI of 2.2 1.4 2.1 1.4 0.96 1.5 0.61 1.0 0.52 OR Quart3 5.7 5.2 6.4 3.7 3.4 4.0 2.0 5.5 1.8

OR Quart 4 20 6.1 28 3.9 2.4 4.0 2.0 2.5 1.8 p Value 0 2.3E-9 0 2.8E-9 0.0054 1.9E-9 0.011 0.027 0.037 95% CI of 13 3.4 17 2.5 1.3 2.6 1.2 1.1 1.0 OR Quart4 31 11 47 6.0 4.4 6.4 3.4 5.8 3.0

Metalloproteinase inhibitor 2 / (Weight Adjusted Urine Output)

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Average 2710 65900 2710 7190 2710 7260

Stdev 32100 897000 32100 85600 32100 52500 p(t-test) 4.5E-4 0.11 0.18

Min 0.0558 0.114 0.0558 0.182 0.0558 0.181

Max 579000 1.71E7 579000 1210000 579000 449000 n (Samp) 2509 370 2509 215 2509 100 n (Patient) 331 370 331 215 331 100

Insulin-like growth factor-binding protein 7 X Serum Creatinine sCr or UO Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 42.6 111 42.6 65.8 42.6 57.8

Average 57.1 165 57.1 90.6 57.1 73.5

Stdev 56.2 177 56.2 94.3 56.2 59.2 p(t-test) 6.2E-112 1.7E-15 0.0028

Min 2.00 9.20 2.00 9.29 2.00 12.8

Max 765 1820 765 845 765 337 n (Samp) 2355 411 2355 230 2355 110 n (Patient) 274 411 274 230 274 110 sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 51.2 176 51.2 102 51.2 74.2

Average 71.3 238 71.3 154 71.3 110

Stdev 73.0 234 73.0 172 73.0 88.1 p(t-test) 7.1E-121 6.0E-26 1.7E-5

Min 2.00 9.20 2.00 11.0 2.00 14.9

Max 973 1820 973 1020 973 453 n (Samp) 4314 152 4314 99 4314 68 n (Patient) 517 152 517 99 517 68

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 44.5 111 44.5 68.3 44.5 58.2

Average 60.4 170 60.4 100 60.4 95.0

Stdev 60.9 187 60.9 119 60.9 102 p(t-test) 2.6E-109 2.0E-17 4.4E-8

Min 2.00 10.0 2.00 9.29 2.00 12.8

Max 869 1820 869 991 869 589 n (Samp) 2822 370 2822 220 2822 103 n (Patient) 330 370 330 220 330 103

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Cutoff 4 63.3 77.4 66.3 63.3 77.4 66.3 63.3 77.4 66.3 Sens 4 73% 78% 72% 51% 65% 52% 45% 47% 48% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 80.5 99.6 85.3 80.5 99.6 85.3 80.5 99.6 85.3 Sens 5 65% 74% 62% 40% 51% 40% 30% 37% 35% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 112 145 118 112 145 118 112 145 118 Sens 6 49% 58% 47% 25% 30% 25% 18% 24% 22% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.6 1.9 1.6 2.1 1.2 1.7 1.6 3.8 1.0 p Value 0.067 0.19 0.092 0.0032 0.67 0.039 0.15 0.018 1.0 95% CI of 0.97 0.74 0.93 1.3 0.52 1.0 0.84 1.3 0.53 OR Quart2 2.6 4.7 2.6 3.5 2.8 2.8 3.1 11 1.9

OR Quart 3 3.5 2.6 3.5 2.4 2.2 2.1 2.1 5.3 1.3 p Value 3.8E-8 0.033 1.7E-7 4.6E-4 0.037 0.0022 0.025 0.0022 0.36 95% CI of 2.2 1.1 2.2 1.5 1.0 1.3 1.1 1.8 0.72 OR Quart3 5.5 6.2 5.6 3.9 4.7 3.4 3.9 16 2.4

OR Quart 4 14 18 13 4.9 5.7 4.2 2.9 7.2 2.2 p Value 0 1.6E-13 0 1.6E-11 4.7E-7 3.1E-10 6.5E-4 2.4E-4 0.0064 95% CI of 9.5 8.4 8.5 3.1 2.9 2.7 1.6 2.5 1.2 OR Quart4 22 39 20 7.7 11 6.5 5.2 20 3.8

Metalloproteinase inhibitor 2 X Serum Creatinine

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 2.09 5.26 2.09 3.18 2.09 2.89

Average 2.91 8.01 2.91 5.18 2.91 10.5

Stdev 3.28 9.48 3.28 10.6 3.28 42.2 p(t-test) 6.0E-89 3.3E-14 1.5E-18

Min 0.120 0.481 0.120 0.414 0.120 0.600

Max 51.2 69.5 51.2 118 51.2 348 n (Samp) 2822 370 2822 220 2822 103 n (Patient) 330 370 330 220 330 103

Insulin-like growth factor-binding protein 7 X Serum Creatinine / (Weight Adjusted Urine Output)

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Cutoff 3 48.2 42.4 68.9 15.8 21.9 17.8 11.8 25.6 10.7 Sens 3 90% 90% 90% 90% 90% 90% 90% 92% 91% Spec 3 57% 40% 65% 26% 25% 27% 20% 28% 18%

Cutoff 4 77.4 130 81.0 77.4 130 81.0 77.4 130 81.0 Sens 4 85% 73% 86% 53% 57% 58% 46% 47% 47% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 112 199 119 112 199 119 112 199 119 Sens 5 76% 59% 79% 47% 40% 47% 36% 34% 37% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 188 364 202 188 364 202 188 364 202 Sens 6 61% 47% 64% 27% 25% 28% 18% 17% 21% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.3 1.8 1.3 1.6 1.6 1.7 0.64 2.4 0.89 p Value 0.35 0.20 0.46 0.070 0.24 0.058 0.22 0.098 0.73 95% CI of 0.72 0.74 0.63 0.96 0.73 0.98 0.32 0.85 0.46 OR Quart2 2.5 4.2 2.7 2.7 3.6 3.0 1.3 6.9 1.7

OR Quart 3 4.4 4.0 4.5 2.3 2.2 2.3 1.5 4.1 1.00 p Value 4.2E-8 5.5E-4 1.5E-6 8.3E-4 0.037 0.0016 0.19 0.0052 1.00 95% CI of 2.6 1.8 2.4 1.4 1.0 1.4 0.82 1.5 0.52 OR Quart3 7.5 8.7 8.3 3.8 4.7 3.9 2.6 11 1.9

OR Quart 4 30 12 36 5.2 4.7 6.1 2.3 4.5 2.4 p Value 0 1.5E-11 0 2.0E-12 1.3E-5 1.8E-13 0.0035 0.0026 0.0017 95% CI of 18 5.9 20 3.3 2.3 3.8 1.3 1.7 1.4 OR Quart4 49 25 63 8.3 9.3 9.8 3.9 12 4.2

Metalloproteinase inhibitor 2 X Serum Creatinine / (Weight Adjusted Urine Output)

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 n (Patient) 514 143 514 93 514 59

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 2.01 14.5 2.01 4.82 2.01 3.54

Average 2180 35400 2180 3530 2180 4960

Stdev 26400 353000 26400 37800 26400 34800 p(t-test) 5.2E-6 0.49 0.31

Min 0.0191 0.0807 0.0191 0.133 0.0191 0.0985

Max 548000 6330000 548000 485000 548000 270000 n (Samp) 2428 368 2428 213 2428 99 n (Patient) 330 368 330 213 330 99

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only p Value 0 2.1E-11 0 6.1E-11 4.3E-4 1.4E-11 0.0027 0.0022 0.0033 95% CI of 16 5.3 19 2.8 1.6 3.0 1.4 1.7 1.3 OR Quart4 43 21 61 6.6 5.1 7.4 4.2 10 4.0

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Sens 1 70% 70% 70% 70% 71% 70% 71% 71% 71% Spec 1 66% 58% 69% 41% 37% 44% 41% 38% 37%

Cutoff 2 0.191 0.159 0.238 0.0908 0.103 0.103 0.0788 0.128 0.0676 Sens 2 80% 81% 80% 80% 81% 80% 80% 81% 81% Spec 2 49% 37% 56% 29% 27% 32% 26% 32% 22%

Cutoff 3 0.0835 0.0769 0.118 0.0497 0.0610 0.0507 0.0448 0.0507 0.0369 Sens 3 90% 90% 90% 90% 91% 90% 90% 90% 90% Spec 3 27% 21% 36% 17% 17% 17% 15% 14% 12%

Cutoff 4 0.386 0.488 0.381 0.386 0.488 0.381 0.386 0.488 0.381 Sens 4 66% 59% 70% 36% 47% 40% 39% 39% 45% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 0.556 0.702 0.554 0.556 0.702 0.554 0.556 0.702 0.554 Sens 5 53% 53% 57% 27% 34% 28% 27% 36% 29% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 0.919 1.20 0.938 0.919 1.20 0.938 0.919 1.20 0.938 Sens 6 38% 35% 39% 15% 23% 17% 13% 19% 16% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.3 1.5 1.6 1.4 1.2 1.3 0.95 1.3 0.69 p Value 0.18 0.22 0.071 0.095 0.63 0.27 0.88 0.45 0.26 95% CI of 0.88 0.80 0.96 0.94 0.62 0.83 0.52 0.63 0.36 OR Quart2 2.0 2.8 2.5 2.2 2.2 2.0 1.8 2.8 1.3

OR Quart 3 2.4 1.7 3.4 1.5 1.1 1.8 1.5 1.5 1.1 p Value 3.6E-6 0.077 5.9E-8 0.063 0.74 0.0081 0.17 0.27 0.77 95% CI of 1.7 0.94 2.2 0.98 0.59 1.2 0.85 0.72 0.61 OR Quart3 3.6 3.2 5.2 2.2 2.1 2.7 2.6 3.1 1.9

OR Quart 4 7.2 5.2 9.9 2.0 2.3 2.2 1.7 2.2 1.7 p Value 0 1.1E-9 0 8.8E-4 0.0044 2.0E-4 0.048 0.026 0.041 95% CI of 5.1 3.1 6.6 1.3 1.3 1.4 1.0 1.1 1.0 OR Quart4 10 8.8 15 2.9 4.0 3.2 3.0 4.4 2.9

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 X

Serum Creatinine

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Stdev 1.05 7.80 1.05 3.15 1.05 1.46 p(t-test) 5.1E-61 1.3E-18 0.0041

Min 0.00240 0.0152 0.00240 0.0185 0.00240 0.0178

Max 31.2 64.2 31.2 20.2 31.2 10.4 n (Samp) 4314 152 4314 99 4314 68 n (Patient) 517 152 517 99 517 68

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 0.133 0.610 0.133 0.233 0.133 0.239

Average 0.309 1.70 0.309 0.935 0.309 1.60

Stdev 0.658 3.51 0.658 4.52 0.658 7.48 p(t-test) 8.8E-74 7.8E-11 7.8E-17

Min 0.00240 0.0120 0.00240 0.0116 0.00240 0.0182

Max 14.6 38.0 14.6 64.1 14.6 62.2 n (Samp) 2822 370 2822 220 2822 103 n (Patient) 330 370 330 220 330 103

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

OR Quart 3 3.8 1.8 3.8 2.1 1.5 2.3 1.8 2.4 1.2 p Value 8.8E-9 0.13 5.6E-8 0.0012 0.25 5.6E-4 0.046 0.081 0.64 95% CI of 2.4 0.83 2.4 1.4 0.76 1.4 1.0 0.90 0.63 OR Quart3 6.1 3.9 6.2 3.4 2.9 3.8 3.3 6.1 2.1

OR Quart 4 15 12 15 3.3 3.3 3.9 2.2 4.9 2.1 p Value 0 2.1E-13 0 1.1E-7 6.6E-5 5.1E-9 0.0055 4.0E-4 0.0072 95% CI of 9.8 6.0 9.3 2.1 1.8 2.5 1.3 2.0 1.2 OR Quart4 23 22 23 5.0 5.9 6.1 4.0 12 3.6

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 /

(Weight Adjusted Urine Output)

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

AUC 0.81 0.70 0.84 0.62 0.60 0.64 0.59 0.60 0.58

SE 0.014 0.025 0.013 0.021 0.031 0.021 0.030 0.039 0.030

P 0 1.3E-15 0 1.7E-8 9.0E-4 8.9E-11 0.0017 0.012 0.0066 nCohort 1 2069 3862 2509 2069 3862 2509 2069 3862 2509 nCohort 2 408 145 370 223 93 215 107 61 100

Cutoff 1 0.632 0.427 0.888 0.143 0.179 0.182 0.135 0.212 0.109 Sens 1 70% 70% 70% 70% 71% 70% 70% 70% 70% Spec 1 77% 57% 83% 45% 39% 50% 43% 42% 38%

Cutoff 2 0.354 0.248 0.507 0.0822 0.0794 0.0934 0.0522 0.156 0.0432 Sens 2 80% 80% 80% 80% 81% 80% 80% 80% 80% Spec 2 65% 45% 72% 33% 25% 35% 26% 36% 23%

Cutoff 3 0.137 0.0797 0.208 0.0448 0.0512 0.0435 0.0205 0.0240 0.0217 Sens 3 90% 90% 90% 90% 90% 90% 91% 90% 90% Spec 3 44% 25% 52% 24% 20% 23% 14% 12% 15%

Cutoff 4 0.438 0.791 0.446 0.438 0.791 0.446 0.438 0.791 0.446 Sens 4 77% 60% 82% 46% 45% 49% 43% 44% 43% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 0.754 1.33 0.752 0.754 1.33 0.752 0.754 1.33 0.752 Sens 5 68% 50% 73% 31% 30% 33% 30% 31% 31% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 1.39 2.74 1.42 1.39 2.74 1.42 1.39 2.74 1.42 Sens 6 54% 34% 59% 20% 20% 23% 18% 16% 19% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.4 1.4 1.4 1.7 0.83 1.6 0.71 1.9 0.60 p Value 0.25 0.32 0.28 0.028 0.60 0.084 0.31 0.15 0.14 95% CI of 0.81 0.72 0.76 1.1 0.42 0.94 0.36 0.80 0.31 OR Quart2 2.3 2.7 2.6 2.7 1.7 2.6 1.4 4.5 1.2

OR Quart 3 3.3 2.2 3.7 2.2 1.5 2.4 1.5 2.1 1.1 p Value 2.1E-7 0.014 1.9E-6 8.9E-4 0.23 1.9E-4 0.20 0.077 0.77 95% CI of 2.1 1.2 2.1 1.4 0.79 1.5 0.82 0.92 0.61 OR Quart3 5.2 4.0 6.3 3.4 2.7 3.9 2.6 5.0 1.9

OR Quart 4 16 5.5 23 3.1 1.9 3.5 2.0 2.7 1.7 p Value 0 2.8E-9 0 4.5E-7 0.027 5.5E-8 0.010 0.019 0.052 95% CI of 11 3.1 14 2.0 1.1 2.2 1.2 1.2 1.00 OR Quart4 25 9.6 37 4.7 3.4 5.4 3.5 6.0 2.9

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 X

Serum Creatinine / (Weight Adjusted Urine Output)

sCr or UO Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 n (Patient) 272 404 272 221 272 105 sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 0.218 1.62 0.218 0.723 0.218 0.422

Average 292 20000 292 8510 292 2780

Stdev 4050 214000 4050 54800 4050 18500 p(t-test) 2.1E-8 9.5E-17 4.3E-5

Min 0.000381 0.00282 0.000381 0.00221 0.000381 0.00635

Max 151000 2550000 151000 486000 151000 141000 n (Samp) 3742 143 3742 93 3742 59 n (Patient) 514 143 514 93 514 59

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 0.133 1.63 0.133 0.379 0.133 0.266

Average 157 13600 157 517 157 460

Stdev 2080 200000 2080 6290 2080 3250 p(t-test) 9.4E-4 0.060 0.17

Min 0.000381 0.00161 0.000381 0.00419 0.000381 0.00257

Max 58400 3800000 58400 89500 58400 26200 n (Samp) 2428 368 2428 213 2428 99 n (Patient) 330 368 330 213 330 99

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Sens 6 58% 46% 61% 25% 22% 24% 22% 24% 24% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.1 1.3 1.1 1.5 1.4 1.4 0.89 2.4 0.80 p Value 0.77 0.53 0.73 0.086 0.35 0.19 0.73 0.081 0.51 95% CI of 0.61 0.57 0.57 0.94 0.68 0.84 0.46 0.90 0.42 OR Quart2 2.0 3.0 2.2 2.5 3.0 2.4 1.7 6.2 1.5

OR Quart 3 4.1 3.1 4.0 2.1 1.9 2.4 1.6 2.7 1.00 p Value 1.3E-8 0.0023 1.3E-6 0.0018 0.066 5.3E-4 0.11 0.039 1.00 95% CI of 2.5 1.5 2.3 1.3 0.96 1.5 0.90 1.1 0.54 OR Quart3 6.7 6.3 7.0 3.4 3.9 3.8 2.9 6.9 1.8

OR Quart 4 22 9.8 28 3.9 3.5 4.4 2.1 3.9 2.0 p Value 0 1.2E-11 0 1.4E-9 1.5E-4 2.0E-10 0.0081 0.0031 0.014 95% CI of 14 5.1 16 2.5 1.8 2.8 1.2 1.6 1.1 OR Quart4 35 19 46 6.0 6.7 6.9 3.7 9.6 3.4

Serum Creatinine

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 n (Patient) 331 378 331 226 331 108

Serum Creatinine / (Weight Adjusted Urine Output)

sCr or UO Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Min 0.0159 0.0673 0.0159 0.0760 0.0159 0.0645

Max 154000 130000 154000 119000 154000 80000 n (Samp) 2010 404 2010 222 2010 105 n (Patient) 272 404 272 222 272 105 sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 0.863 2.17 0.863 1.54 0.863 1.31

Average 767 3560 767 3300 767 3260

Stdev 8440 29400 8440 18500 8440 19300 p(t-test) 0.0011 0.0060 0.029

Min 0.0159 0.102 0.0159 0.0920 0.0159 0.170

Max 180000 330000 180000 119000 180000 140000 n (Samp) 3758 143 3758 94 3758 59 n (Patient) 514 143 514 94 514 59

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 0.616 2.53 0.616 1.33 0.616 1.03

Average 687 3150 687 563 687 1420

Stdev 8520 18600 8520 6100 8520 10000 p(t-test) 2.5E-5 0.83 0.41

Min 0.0159 0.0673 0.0159 0.0760 0.0159 0.0645

Max 230000 214000 230000 80000 230000 80000 n (Samp) 2437 369 2437 214 2437 99 n (Patient) 330 369 330 214 330 99

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Sens 5 75% 54% 76% 45% 38% 47% 30% 29% 32% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 1.96 3.20 2.07 1.96 3.20 2.07 1.96 3.20 2.07 Sens 6 59% 37% 62% 28% 22% 29% 16% 20% 21% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 0.77 1.6 0.86 2.1 2.0 1.9 1.4 2.0 1.0 p Value 0.42 0.26 0.70 0.0075 0.087 0.024 0.30 0.16 1.0 95% CI of 0.41 0.72 0.41 1.2 0.90 1.1 0.72 0.75 0.50 OR Quart2 1.5 3.3 1.8 3.6 4.5 3.3 2.9 5.4 2.0

OR Quart 3 4.0 2.7 4.9 2.4 2.9 2.3 2.4 3.6 1.9 p Value 1.5E-8 0.0056 4.3E-8 0.0011 0.0056 0.0028 0.0060 0.0064 0.052 95% CI of 2.5 1.3 2.8 1.4 1.4 1.3 1.3 1.4 1.00 OR Quart3 6.4 5.4 8.7 4.1 6.3 3.9 4.6 8.9 3.4

OR Quart 4 22 8.5 29 6.3 4.7 6.6 2.8 3.4 2.5 p Value 0 4.0E-11 0 6.3E-14 2.9E-5 4.0E-14 0.0011 0.0092 0.0030 95% CI of 14 4.5 17 3.9 2.3 4.0 1.5 1.4 1.4 OR Quart4 34 16 50 10 9.8 11 5.3 8.5 4.5

[0113] Table 2: Comparison of marker levels in samples collected from Cohort 1

(patients that did not progress beyond RIFLE stage 0 or R) and in samples collected from subjects at 0, 24 hours, and 48 hours prior to reaching stage I or F in Cohort 2. Insulinlike growth factor-binding protein 7 and Metalloproteinase inhibitor 2 were measured in urine.

Insulin-like growth factor-binding protein 7

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 n (Patient) 621 61 621 56 621 44

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 70.5 153 70.5 86.3 70.5 81.2

Average 85.4 176 85.4 120 85.4 98.3

Stdev 62.6 112 62.6 89.6 62.6 73.0 p(t-test) 5.2E-68 1.5E-9 0.083

Min 10.0 20.0 10.0 20.0 10.0 20.0

Max 600 600 600 600 600 438 n (Samp) 4633 165 4633 127 4633 72 n (Patient) 526 165 526 127 526 72

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only p Value 8.9E-16 4.6E-5 3.0E-13 2.2E-8 7.5E-5 1.0E-6 0.022 0.0012 0.30 95% CI of 6.4 2.4 6.5 3.2 2.6 2.7 1.1 2.0 0.72 OR Quart4 21 12 25 11 17 9.8 3.7 17 2.9

Metalloproteinase inhibitor 2

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Sens 1 70% 70% 70% 71% 71% 70% 71% 70% 71% Spec 1 69% 61% 68% 45% 54% 46% 39% 48% 38%

Cutoff 2 3.88 2.96 3.90 2.39 2.21 2.64 2.17 2.55 2.05 Sens 2 80% 80% 80% 80% 80% 80% 81% 82% 81% Spec 2 59% 40% 58% 32% 26% 37% 28% 33% 25%

Cutoff 3 2.88 2.28 2.90 1.73 1.73 1.87 0 1.63 0 Sens 3 90% 90% 90% 91% 93% 91% 100% 91% 100% Spec 3 41% 28% 41% 19% 18% 21% 0% 16% 0%

Cutoff 4 4.66 4.88 4.73 4.66 4.88 4.73 4.66 4.88 4.73 Sens 4 68% 66% 68% 42% 59% 40% 38% 50% 31% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 5.69 5.98 5.80 5.69 5.98 5.80 5.69 5.98 5.80 Sens 5 63% 61% 62% 32% 52% 30% 30% 43% 21% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 7.33 7.82 7.63 7.33 7.82 7.63 7.33 7.82 7.63 Sens 6 48% 41% 48% 21% 43% 17% 20% 20% 17% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.9 1.2 3.0 1.4 0.60 1.8 1.6 1.5 1.5 p Value 0.098 0.78 0.019 0.21 0.32 0.071 0.15 0.44 0.24 95% CI of 0.89 0.39 1.2 0.82 0.22 0.95 0.84 0.53 0.76 OR Quart2 4.1 3.5 7.7 2.5 1.6 3.3 3.1 4.2 3.0

OR Quart 3 3.8 1.5 5.5 1.8 1.1 2.2 1.3 1.2 1.3 p Value 2.1E-4 0.44 1.5E-4 0.036 0.83 0.0087 0.40 0.78 0.48 95% CI of 1.9 0.53 2.3 1.0 0.47 1.2 0.68 0.39 0.64 OR Quart3 7.7 4.2 13 3.1 2.6 4.0 2.6 3.5 2.6

OR Quart 4 14 6.7 20 2.9 2.9 3.1 2.0 3.7 1.4 p Value 1.3E-15 1.7E-5 1.3E-12 4.9E-5 0.0035 1.1E-4 0.027 0.0046 0.38 95% CI of 7.4 2.8 8.7 1.7 1.4 1.7 1.1 1.5 0.68 OR Quart4 27 16 45 4.7 6.1 5.5 3.8 9.2 2.7

Weight Adjusted Urine Output

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Stdev 1.41 2.29 1.41 0.542 1.41 1.05 p(t-test) 0.27 0.0013 0.069

Min 1.00E-5 1.00E-5 1.00E-5 1.00E-5 1.00E-5 1.00E-5

Max 21.5 16.7 21.5 3.00 21.5 6.00 n (Samp) 4661 58 4661 55 4661 41 n (Patient) 617 58 617 55 617 41

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 0.919 0.270 0.919 0.538 0.919 0.719

Average 1.39 0.333 1.39 0.890 1.39 1.19

Stdev 1.54 0.414 1.54 1.55 1.54 1.24 p(t-test) 3.1E-18 4.8E-4 0.28

Min 1.00E-5 1.00E-5 1.00E-5 1.00E-5 1.00E-5 1.00E-5

Max 21.5 4.67 21.5 15.8 21.5 5.71 n (Samp) 3986 164 3986 121 3986 73 n (Patient) 525 164 525 121 525 73

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

OR Quart 3 2.6 1.4 5.0 3.3 5.4 2.9 1.8 2.2 1.2 p Value 0.033 0.39 0.037 6.9E-4 0.0075 0.0056 0.070 0.14 0.61 95% CI of 1.1 0.62 1.1 1.6 1.6 1.4 0.95 0.77 0.61 OR Quart3 6.3 3.4 23 6.5 19 6.3 3.3 6.4 2.3

OR Quart 4 27 3.2 86 6.7 8.8 7.4 1.8 3.6 1.6 p Value 0 0.0028 4.2E-10 6.9E-9 3.6E-4 2.5E-8 0.070 0.011 0.16 95% CI of 13 1.5 21 3.5 2.7 3.7 0.95 1.3 0.84 OR Quart4 58 6.7 350 13 29 15 3.3 9.8 3.0

Insulin-like growth factor-binding protein 7 / (Weight Adjusted Urine Output)

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

SE 0.017 0.039 0.017 0.025 0.040 0.027 0.032 0.046 0.035

P 0 4.3E-8 0 2.1E-14 2.0E-8 l.lE-11 0.0019 7.6E-5 0.072 nCohort 1 3691 4641 3970 3691 4641 3970 3691 4641 3970 nCohort 2 191 57 163 139 54 121 87 41 72

Cutoff 1 270 148 324 94.7 138 94.7 69.2 100 59.7 Sens 1 70% 70% 71% 71% 70% 70% 70% 71% 71% Spec 1 87% 66% 89% 57% 63% 56% 48% 53% 42%

Cutoff 2 189 74.2 226 63.8 69.8 66.1 32.7 87.1 27.6 Sens 2 80% 81% 80% 81% 81% 80% 80% 80% 81% Spec 2 78% 45% 82% 45% 43% 45% 27% 49% 23%

Cutoff 3 128 35.9 155 34.4 55.0 40.2 18.3 25.4 17.5 Sens 3 90% 91% 90% 91% 91% 90% 91% 90% 90% Spec 3 67% 25% 72% 28% 36% 31% 16% 19% 15%

Cutoff 4 142 171 146 142 171 146 142 171 146 Sens 4 88% 65% 91% 55% 65% 54% 44% 56% 36% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 204 254 209 204 254 209 204 254 209 Sens 5 77% 54% 82% 46% 48% 45% 32% 46% 28% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 330 428 344 330 428 344 330 428 344 Sens 6 62% 35% 66% 25% 33% 25% 18% 29% 14% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 2.0 1.6 1.5 2.3 3.4 2.0 0.64 1.00 0.75 p Value 0.26 0.41 0.66 0.027 0.067 0.088 0.26 1.00 0.45 95% CI of 0.60 0.52 0.25 1.1 0.92 0.90 0.30 0.29 0.35 OR Quart2 6.7 4.9 9.0 4.9 12 4.5 1.4 3.5 1.6

OR Quart 3 6.1 2.4 10 3.4 4.4 3.9 1.6 2.2 1.3 p Value 8.2E-4 0.099 0.0018 8.1E-4 0.022 3.4E-4 0.13 0.14 0.41 95% CI of 2.1 0.85 2.4 1.7 1.2 1.8 0.87 0.77 0.68 OR Quart3 18 6.9 44 6.9 15 8.1 3.0 6.4 2.5

OR Quart 4 46 6.5 79 7.8 9.5 7.0 1.9 4.0 1.4 p Value 5.4E-14 9.9E-5 8.8E-10 1.6E-9 2.1E-4 6.4E-8 0.033 0.0053 0.26 95% CI of 17 2.5 20 4.0 2.9 3.5 1.1 1.5 0.76 OR Quart4 120 17 320 15 31 14 3.5 11 2.8

Metalloproteinase inhibitor 2 / (Weight Adjusted Urine Output)

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 4.27 11.7 4.27 10.9 4.27 9.27

Average 3820 344000 3820 83900 3820 104000

Stdev 46500 2280000 46500 472000 46500 479000 p(t-test) 1.2E-23 1.2E-17 5.7E-23

Min 0.0558 0.0718 0.0558 0.670 0.0558 0.248

Max 1220000 1.71E7 1220000 3240000 1220000 2680000 n (Samp) 4641 57 4641 54 4641 41 n (Patient) 617 57 617 54 617 41

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 3.73 24.7 3.73 8.20 3.73 4.87

Average 4260 159000 4260 26800 4260 24800

Stdev 51700 1410000 51700 295000 51700 166000 p(t-test) 9.2E-12 6.7E-4 0.0020

Min 0.0558 0.257 0.0558 0.156 0.0558 0.210

Max 1290000 1.71E7 1290000 3240000 1290000 1340000 n (Samp) 3970 163 3970 121 3970 72 n (Patient) 525 163 525 121 525 72

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

95% CI of 0.19 0.17 0.14 0.76 0.77 0.97 0.50 0.29 0.49

OR Quart2 2.4 2.0 7.1 2.9 6.4 4.2 2.0 3.5 2.1

OR Quart 3 4.4 1.9 9.7 2.1 1.8 2.6 1.6 2.6 1.3 p Value 0.0011 0.18 0.0023 0.019 0.29 0.0081 0.16 0.068 0.40

95% CI of 1.8 0.74 2.2 1.1 0.60 1.3 0.84 0.93 0.68

OR Quart3 11 4.7 42 3.9 5.4 5.2 3.0 7.4 2.6

OR Quart 4 31 4.8 81 5.0 5.9 5.7 1.9 3.6 1.5 p Value 2.2E-16 1.7E-4 7.6E-10 2.1E-8 2.5E-4 1.4E-7 0.040 0.011 0.25

95% CI of 13 2.1 20 2.9 2.3 3.0 1.0 1.3 0.76

OR Quart4 69 11 330 8.8 15 11 3.5 9.8 2.9

Insulin-like growth factor-binding protein 7 X Serum Creatinine

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

AUC 0.85 0.88 0.83 0.72 0.81 0.70 0.67 0.78 0.62

SE 0.018 0.028 0.020 0.024 0.035 0.027 0.032 0.042 0.036

P 0 0 0 0 0 6.0E-14 2.6E-7 2.8E-11 6.2E-4 nCohort 1 4155 5178 4425 4155 5178 4425 4155 5178 4425 nCohort 2 190 61 162 144 55 125 87 44 70

Cutoff 1 100 142 101 62.2 114 60.2 53.9 94.2 51.4 Sens 1 70% 70% 70% 70% 71% 70% 70% 70% 70% Spec 1 82% 88% 80% 62% 82% 59% 55% 75% 51%

Cutoff 2 69.7 91.2 70.3 45.5 73.5 45.4 42.5 70.9 42.2 Sens 2 80% 80% 80% 81% 80% 80% 80% 82% 80% Spec 2 67% 74% 66% 46% 65% 45% 42% 63% 41%

Cutoff 3 55.6 62.3 52.1 34.9 52.8 33.6 28.4 37.5 28.4 Sens 3 90% 90% 90% 90% 91% 90% 91% 91% 90% Spec 3 56% 57% 52% 34% 49% 32% 26% 33% 26%

Cutoff 4 74.4 82.5 76.9 74.4 82.5 76.9 74.4 82.5 76.9 Sens 4 78% 85% 78% 61% 76% 58% 52% 75% 44% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 96.0 107 99.7 96.0 107 99.7 96.0 107 99.7 Sens 5 71% 75% 70% 50% 73% 44% 34% 55% 27% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 135 156 145 135 156 145 135 156 145 Sens 6 57% 69% 54% 35% 55% 27% 23% 41% 19% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 4.7 >3.0 4.4 3.3 0.50 4.1 2.0 1.00 1.9 p Value 0.015 <0.34 0.022 0.0055 0.42 0.0022 0.13 1.00 0.19 95% CI of 1.4 >0.31 1.2 1.4 0.091 1.7 0.81 0.20 0.74 OR Quart2 16 na 15 7.8 2.7 10.0 5.0 5.0 4.7

OR Quart 3 11 >10 9.2 5.4 2.0 5.6 4.2 2.3 3.9 p Value 9.8E-5 <0.028 2.8E-4 4.4E-5 0.26 1.1E-4 6.6E-4 0.22 0.0013 95% CI of 3.2 >1.3 2.8 2.4 0.60 2.4 1.8 0.60 1.7 OR Quart3 35 na 30 12 6.7 14 9.7 9.1 9.0

OR Quart 4 54 >50 44 12 11 11 5.4 11 3.3 p Value 8.8E-12 <l.lE-4 l .OE-10 5.5E-10 7.3E-6 2.8E-8 4.4E-5 1.0E-4 0.0055 95% CI of 17 >6.9 14 5.4 3.8 4.7 2.4 3.2 1.4 OR Quart4 170 na 140 26 30 25 12 35 7.8

Metalloproteinase inhibitor 2 X Serum Creatinine

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 2.60 12.3 2.60 8.26 2.60 5.40

Average 3.74 27.2 3.74 16.7 3.74 8.58

Stdev 4.54 57.8 4.54 30.0 4.54 13.2 p(t-test) 1.3E-118 5.7E-67 9.5E-12

Min 0.120 1.40 0.120 0.534 0.120 0.600

Max 69.5 374 69.5 189 69.5 88.4 n (Samp) 5178 61 5178 55 5178 44 n (Patient) 620 61 620 55 620 44

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 2.40 7.35 2.40 3.93 2.40 3.17

Average 4.04 11.8 4.04 8.75 4.04 7.98

Stdev 14.6 11.8 14.6 21.9 14.6 28.2 p(t-test) 3.2E-11 4.8E-4 0.028

Min 0.120 0.840 0.120 0.481 0.120 0.516

Max 549 63.3 549 213 549 236 n (Samp) 4425 162 4425 125 4425 70 n (Patient) 525 162 525 125 525 70

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only p Value 0.011 0.21 0.0072 0.0081 1.0 0.0097 0.033 0.74 0.095 95% CI of 1.5 0.45 1.7 1.3 0.25 1.3 1.1 0.33 0.88 OR Quart2 18 36 33 5.2 4.0 5.5 6.2 4.7 5.3

OR Quart 3 12 5.0 15 3.0 2.0 3.1 3.9 1.3 3.6 p Value 3.7E-5 0.14 1.9E-4 0.0020 0.26 0.0024 0.0013 0.74 0.0027 95% CI of 3.7 0.58 3.7 1.5 0.60 1.5 1.7 0.34 1.6 OR Quart3 39 43 64 5.9 6.7 6.3 9.1 4.7 8.4

OR Quart 4 52 53 64 7.0 10 6.2 5.1 7.6 3.3 p Value 1.5E-11 8.5E-5 6.1E-9 2.2E-9 1.2E-5 1.3E-7 8.6E-5 1.4E-4 0.0055 95% CI of 17 7.3 16 3.7 3.6 3.1 2.3 2.7 1.4 OR Quart4 160 380 260 13 28 12 12 22 7.8

Insulin-like growth factor-binding protein 7 X Serum Creatinine / (Weight Adjusted Urine Output)

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

AUC 0.90 0.81 0.91 0.74 0.79 0.72 0.65 0.73 0.61

SE 0.015 0.035 0.016 0.025 0.037 0.027 0.033 0.045 0.036

P 0 0 0 0 2.9E-15 6.7E-16 8.7E-6 2.5E-7 0.0019 nCohort 1 3574 4492 3847 3574 4492 3847 3574 4492 3847 nCohort 2 187 57 159 137 54 119 85 41 70

Cutoff 1 305 200 370 100 168 95.6 62.3 97.7 45.5 Sens 1 70% 70% 70% 70% 70% 71% 71% 71% 70% Spec 1 91% 79% 92% 68% 74% 65% 54% 61% 44%

Cutoff 2 182 109 203 58.3 128 54.9 32.2 74.6 25.7 Sens 2 80% 81% 81% 80% 81% 81% 80% 80% 80% Spec 2 83% 63% 83% 52% 68% 49% 36% 53% 30%

Cutoff 3 111 52.0 139 24.6 25.3 24.2 14.8 41.1 14.8 Sens 3 90% 91% 91% 91% 91% 91% 91% 90% 90% Spec 3 71% 43% 75% 30% 26% 29% 20% 37% 20%

Cutoff 4 108 140 114 108 140 114 108 140 114 Sens 4 91% 74% 93% 69% 78% 65% 52% 56% 49% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 164 212 174 164 212 174 164 212 174 Sens 5 82% 67% 86% 55% 61% 50% 34% 51% 30% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 272 390 307 272 390 307 272 390 307 Sens 6 72% 56% 73% 31% 46% 24% 25% 41% 21% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 2.5 3.0 2.0 2.4 0.50 1.8 1.4 1.0 1.6 p Value 0.27 0.18 0.57 0.039 0.42 0.17 0.41 1.0 0.30 95% CI of 0.49 0.61 0.18 1.0 0.091 0.79 0.62 0.20 0.67 OR Quart2 13 15 22 5.5 2.7 4.1 3.2 5.0 3.6

OR Quart 3 11 4.5 15 3.2 3.3 2.8 2.4 4.4 2.1 p Value 0.0011 0.054 0.0085 0.0047 0.038 0.0080 0.019 0.022 0.063 95% CI of 2.6 0.98 2.0 1.4 1.1 1.3 1.2 1.2 0.96 OR Quart3 48 21 120 7.1 10 6.1 5.1 15 4.7

OR Quart 4 95 21 160 12 9.0 8.2 3.8 7.5 3.2 p Value 1.8E-10 3.0E-5 3.9E-7 5.1E-11 3.4E-5 4.3E-9 2.0E-4 0.0011 0.0028 95% CI of 23 5.0 23 5.6 3.2 4.0 1.9 2.2 1.5 OR Quart4 380 86 1200 24 25 16 7.7 25 6.8

Metalloproteinase inhibitor 2 X Serum Creatinine / (Weight Adjusted Urine Output)

sCr or UO Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Max 1340000 6330000 1340000 5510000 1340000 1740000 n (Samp) 3574 187 3574 137 3574 85 n (Patient) 490 187 490 137 490 85 sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 3.21 18.8 3.21 14.8 3.21 9.46

Average 3150 286000 3150 122000 3150 247000

Stdev 39200 1490000 39200 762000 39200 1390000 p(t-test) 4.5E-35 1.7E-21 1.3E-29

Min 0.0191 0.149 0.0191 0.418 0.0191 0.221

Max 1340000 9440000 1340000 5510000 1340000 8840000 n (Samp) 4492 57 4492 54 4492 41 n (Patient) 616 57 616 54 616 41

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 2.66 29.7 2.66 7.01 2.66 5.01

Average 3450 101000 3450 46300 3450 29300

Stdev 42800 660000 42800 505000 42800 211000 p(t-test) 3.4E-18 2.0E-6 2.5E-5

Min 0.0191 0.180 0.0191 0.124 0.0191 0.0903

Max 1340000 6330000 1340000 5510000 1340000 1740000 n (Samp) 3847 159 3847 119 3847 70 n (Patient) 524 159 524 119 524 70

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 13.4 17.9 15.0 13.4 17.9 15.0 13.4 17.9 15.0 Sens 6 70% 51% 70% 31% 46% 29% 22% 34% 17% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.5 2.0 2.0 1.7 0.60 2.1 1.5 1.3 1.3 p Value 0.66 0.42 0.57 0.16 0.48 0.063 0.32 0.74 0.53 95% CI of 0.25 0.37 0.18 0.82 0.14 0.96 0.67 0.34 0.57 OR Quart2 9.0 11 22 3.5 2.5 4.7 3.4 4.7 3.0

OR Quart 3 12 5.5 14 2.4 1.8 3.3 2.4 2.3 1.9 p Value 8.5E-4 0.026 0.010 0.013 0.29 0.0019 0.019 0.18 0.098 95% CI of 2.8 1.2 1.9 1.2 0.60 1.5 1.2 0.69 0.89 OR Quart3 50 25 110 4.7 5.4 7.0 5.1 7.4 4.1

OR Quart 4 95 21 170 6.9 7.6 7.3 3.7 5.8 2.8 p Value 1.7E-10 3.0E-5 3.7E-7 7.7E-10 2.2E-5 3.4E-8 2.8E-4 0.0012 0.0048 95% CI of 24 5.0 23 3.7 3.0 3.6 1.8 2.0 1.4 OR Quart4 390 86 1200 13 19 15 7.5 17 5.9

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Max 80.6 103 80.6 70.5 80.6 23.3 n (Samp) 4633 165 4633 127 4633 72 n (Patient) 526 165 526 127 526 72

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 X Serum Creatinine

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Cutoff 3 0.170 0.243 0.170 0.0773 0.0984 0.0773 0.0404 0.105 0.0400 Sens 3 90% 90% 90% 90% 91% 90% 91% 91% 90% Spec 3 51% 57% 50% 30% 31% 29% 17% 33% 17%

Cutoff 4 0.332 0.386 0.348 0.332 0.386 0.348 0.332 0.386 0.348 Sens 4 78% 72% 80% 56% 73% 54% 44% 66% 37% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 0.487 0.580 0.518 0.487 0.580 0.518 0.487 0.580 0.518 Sens 5 69% 69% 70% 44% 64% 38% 33% 52% 29% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 0.831 0.998 0.934 0.831 0.998 0.934 0.831 0.998 0.934 Sens 6 59% 62% 57% 28% 49% 23% 21% 39% 16% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 5.7 >6.0 4.7 2.5 1.8 2.7 1.7 2.3 1.7 p Value 0.0054 <0.097 0.015 0.011 0.37 0.012 0.15 0.22 0.18 95% CI of 1.7 >0.72 1.3 1.2 0.51 1.2 0.82 0.60 0.78 OR Quart2 20 na 16 5.0 6.0 5.8 3.7 9.1 3.7

OR Quart 3 11 >13 8.5 3.3 1.5 4.2 2.0 2.7 2.0 p Value 6.0E-5 <0.013 4.8E-4 7.1E-4 0.53 1.2E-4 0.058 0.15 0.072 95% CI of 3.5 >1.7 2.6 1.6 0.42 2.0 0.98 0.71 0.94 OR Quart3 37 na 28 6.4 5.3 8.8 4.2 10 4.3

OR Quart 4 52 >43 45 6.8 9.7 6.4 3.3 8.8 2.3 p Value 1.5E-11 <2.0E-4 9.4E-11 4.2E-9 1.6E-5 3.2E-7 7.1E-4 3.7E-4 0.027 95% CI of 17 >6.0 14 3.6 3.5 3.1 1.6 2.7 1.1 OR Quart4 160 na 140 13 27 13 6.4 29 4.9

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 /

(Weight Adjusted Urine Output)

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 n (Samp) 4641 57 4641 54 4641 41 n (Patient) 617 57 617 54 617 41

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 0.266 4.40 0.266 0.649 0.266 0.375

Average 492 88600 492 1890 492 5340

Stdev 8570 844000 8570 20700 8570 39800 p(t-test) 4.9E-11 0.099 4.7E-5

Min 0.00112 0.00514 0.00112 0.00726 0.00112 0.00439

Max 344000 1.03E7 344000 228000 344000 335000 n (Samp) 3970 163 3970 121 3970 72 n (Patient) 525 163 525 121 525 72

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

OR Quart 4 35 6.7 75 5.1 5.1 5.3 2.0 3.8 1.4 p Value 7.5E-15 1.6E-5 1.5E-9 3.5E-8 2.9E-4 5.1E-7 0.030 0.0076 0.32 95% CI of 14 2.8 18 2.9 2.1 2.8 1.1 1.4 0.72 OR Quart4 86 16 300 9.2 12 10 3.6 10 2.7

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 X

Serum Creatinine / (Weight Adjusted Urine Output)

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only nCohort 2 187 57 159 137 54 119 85 41 70

Cutoff 1 1.43 0.962 1.61 0.274 0.635 0.237 0.138 0.360 0.103 Sens 1 70% 70% 70% 70% 70% 71% 71% 71% 70% Spec 1 89% 78% 88% 59% 70% 55% 43% 58% 37%

Cutoff 2 0.956 0.501 1.16 0.156 0.326 0.167 0.0763 0.229 0.0744 Sens 2 80% 81% 81% 80% 81% 81% 80% 80% 80% Spec 2 83% 65% 84% 47% 56% 47% 33% 49% 32%

Cutoff 3 0.492 0.158 0.548 0.0537 0.0537 0.0719 0.0321 0.0926 0.0321 Sens 3 90% 91% 91% 91% 91% 91% 91% 90% 90% Spec 3 71% 41% 72% 28% 24% 31% 20% 32% 20%

Cutoff 4 0.468 0.632 0.492 0.468 0.632 0.492 0.468 0.632 0.492 Sens 4 91% 75% 93% 62% 72% 58% 46% 56% 43% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 0.812 1.10 0.888 0.812 1.10 0.888 0.812 1.10 0.888 Sens 5 82% 67% 85% 48% 61% 44% 35% 56% 30% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 1.62 2.57 1.88 1.62 2.57 1.88 1.62 2.57 1.88 Sens 6 66% 54% 67% 29% 48% 24% 24% 37% 20% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 3.0 3.5 3.0 1.8 0.50 1.8 1.8 1.3 2.1 p Value 0.18 0.12 0.34 0.11 0.33 0.13 0.13 0.74 0.063 95% CI of 0.61 0.73 0.31 0.87 0.12 0.83 0.83 0.34 0.96 OR Quart2 15 17 29 3.8 2.0 3.9 4.0 4.7 4.7

OR Quart 3 11 3.5 17 3.0 1.7 3.3 2.3 2.3 1.8 p Value 0.0011 0.12 0.0057 0.0020 0.32 0.0012 0.027 0.18 0.16 95% CI of 2.6 0.73 2.3 1.5 0.61 1.6 1.1 0.69 0.79 OR Quart3 48 17 130 5.9 4.6 6.7 4.9 7.4 4.1

OR Quart 4 94 21 160 7.2 6.0 6.2 3.5 5.8 2.9 p Value 1.9E-10 2.5E-5 4.4E-7 1.4E-9 5.6E-5 1.2E-7 5.7E-4 0.0012 0.0057 95% CI of 23 5.1 22 3.8 2.5 3.2 1.7 2.0 1.4 OR Quart4 380 88 1100 14 14 12 7.1 17 6.3

Serum Creatinine

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Sens 3 90% 91% 91% 93% 93% 93% 91% 91% 92% Spec 3 28% 55% 26% 20% 17% 19% 20% 40% 19%

Cutoff 4 0.900 0.930 0.900 0.900 0.930 0.900 0.900 0.930 0.900 Sens 4 64% 82% 62% 53% 72% 51% 49% 66% 47% Spec 4 73% 70% 71% 73% 70% 71% 73% 70% 71%

Cutoff 5 1.02 1.10 1.08 1.02 1.10 1.08 1.02 1.10 1.08 Sens 5 59% 78% 55% 42% 62% 37% 40% 57% 36% Spec 5 80% 81% 80% 80% 81% 80% 80% 81% 80%

Cutoff 6 1.30 1.39 1.35 1.30 1.39 1.35 1.30 1.39 1.35 Sens 6 41% 70% 35% 29% 55% 25% 23% 34% 25% Spec 6 91% 90% 90% 91% 90% 90% 91% 90% 90%

OR Quart 2 2.6 1.5 2.4 1.5 0.33 1.2 1.6 0.75 1.7 p Value 0.0012 0.66 0.0046 0.18 0.18 0.64 0.21 0.71 0.18 95% CI of 1.5 0.25 1.3 0.83 0.067 0.63 0.77 0.17 0.78 OR Quart2 4.7 9.0 4.3 2.8 1.6 2.2 3.3 3.4 3.7

OR Quart 3 1.6 4.0 1.5 1.7 2.2 1.6 1.6 2.8 1.6 p Value 0.16 0.079 0.21 0.084 0.12 0.12 0.21 0.082 0.24 95% CI of 0.84 0.85 0.80 0.93 0.82 0.89 0.77 0.88 0.73 OR Quart3 3.0 19 2.9 3.0 5.7 2.8 3.3 8.7 3.6

OR Quart 4 8.5 28 6.6 4.4 6.3 3.2 3.6 6.6 3.4 p Value 2.2E-15 3.8E-6 5.4E-12 2.8E-8 3.1E-5 1.2E-5 1.1E-4 4.6E-4 8.5E-4 95% CI of 5.0 6.8 3.8 2.6 2.7 1.9 1.9 2.3 1.6 OR Quart4 14 120 11 7.4 15 5.4 6.9 19 6.9

Serum Creatinine / (Weight Adjusted Urine Output)

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 0.784 4.30 0.784 1.60 0.784 1.19

Average 819 5610 819 1430 819 2780

Stdev 9040 29400 9040 15600 9040 17300 p(t-test) 2.4E-8 0.48 0.075

Min 0.0159 0.150 0.0159 0.0498 0.0159 0.0753

Max 230000 280000 230000 170000 230000 130000 n (Samp) 3863 160 3863 119 3863 72 n (Patient) 524 160 524 119 524 72

[0114] Table 3: Comparison of the maximum marker levels in samples collected from Cohort 1 (patients that did not progress beyond RIFLE stage 0) and the maximum values in samples collected from subjects between enrollment and 0, 24 hours, and 48 hours prior to reaching stage F in Cohort 2. Insulin-like growth factor-binding protein 7 and Metalloproteinase inhibitor 2 were measured in urine.

Insulin-like growth factor-binding protein 7

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only nCohort 2 53 34 31 48 31 29 33 25 17

Cutoff 1 165 162 201 167 167 142 134 151 134 Sens 1 72% 71% 71% 71% 71% 72% 73% 72% 71% Spec 1 71% 58% 80% 72% 61% 56% 53% 53% 52%

Cutoff 2 130 129 134 134 151 120 118 124 118 Sens 2 81% 82% 81% 81% 81% 83% 82% 80% 82% Spec 2 51% 41% 52% 53% 53% 44% 45% 38% 44%

Cutoff 3 118 114 118 118 118 97.1 94.1 94.1 68.2 Sens 3 91% 91% 90% 92% 90% 93% 91% 92% 94% Spec 3 45% 32% 44% 45% 36% 26% 25% 19% 11%

Cutoff 4 165 193 167 165 193 167 165 193 167 Sens 4 72% 59% 74% 71% 58% 69% 55% 52% 53% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 194 224 201 194 224 201 194 224 201 Sens 5 62% 50% 71% 56% 42% 59% 42% 36% 41% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 239 278 247 239 278 247 239 278 247 Sens 6 51% 41% 58% 40% 32% 45% 30% 28% 35% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 3.2 1.7 2.6 2.4 2.0 1.7 1.3 1.3 1.5 p Value 0.086 0.48 0.27 0.21 0.42 0.47 0.73 0.71 0.65 95% CI of 0.85 0.40 0.48 0.60 0.37 0.40 0.33 0.29 0.25 OR Quart2 12 7.2 14 9.7 11 7.4 4.9 6.1 9.3

OR Quart 3 2.8 3.1 1.0 4.0 6.5 1.3 2.1 2.4 2.0 p Value 0.13 0.091 1.0 0.038 0.016 0.70 0.24 0.21 0.42 95% CI of 0.73 0.83 0.14 1.1 1.4 0.29 0.61 0.60 0.37 OR Quart3 11 12 7.3 15 30 6.2 7.3 9.4 11

OR Quart 4 18 6.3 14 13 7.0 6.8 4.8 3.9 4.3 p Value 5.0E-6 0.0039 4.8E-4 5.7E-5 0.011 0.0031 0.0075 0.041 0.070 95% CI of 5.2 1.8 3.2 3.7 1.6 1.9 1.5 1.1 0.89 OR Quart4 61 22 62 44 32 24 15 14 21

Metalloproteinase inhibitor 2

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Average 7.98 33.7 7.98 31.6 7.98 23.0

Stdev 5.31 56.0 5.31 50.4 5.31 42.3 p(t-test) 1.6E-21 1.7E-21 3.4E-12

Min 1.64 1.20 1.64 1.20 1.64 1.20

Max 56.2 225 56.2 189 56.2 189 n (Samp) 518 34 518 31 518 25 n (Patient) 518 34 518 31 518 25

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 6.07 16.6 6.07 13.9 6.07 10.3

Average 7.15 20.0 7.15 16.3 7.15 12.5

Stdev 5.03 16.1 5.03 14.8 5.03 8.78 p(t-test) 1.1E-21 6.9E-13 6.2E-5

Min 1.62 3.76 1.62 3.76 1.62 1.20

Max 56.2 79.0 56.2 79.0 56.2 32.4 n (Samp) 331 31 331 29 331 17 n (Patient) 331 31 331 29 331 17

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

OR Quart2 3.1 6.1 5.0 9.7 13 5.1 3.6 6.1 4.0

OR Quart 3 1.4 2.0 0.33 2.8 2.6 1.3 1.2 0.99 1.0 p Value 0.55 0.32 0.34 0.14 0.27 0.70 0.75 0.99 1.0 95% CI of 0.44 0.50 0.033 0.72 0.49 0.29 0.36 0.20 0.20 OR Quart3 4.7 8.3 3.2 11 13 6.2 4.2 5.0 5.1

OR Quart 4 13 8.1 10 15 11 7.8 4.1 5.5 3.2 p Value 7.1E-7 9.1E-4 2.2E-4 1.7E-5 0.0016 0.0014 0.0090 0.0085 0.087 95% CI of 4.6 2.3 3.0 4.4 2.5 2.2 1.4 1.5 0.84 OR Quart4 35 28 36 52 47 27 12 19 12

Weight Adjusted Urine Output

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

AUC 0.24 0.34 0.16 0.24 0.34 0.17 0.34 0.39 0.28

SE 0.040 0.052 0.045 0.042 0.055 0.047 0.054 0.061 0.072

P 5.5E-11 0.0027 2.3E-14 1.7E-9 0.0036 2.4E-12 0.0026 0.067 0.0025 nCohort 1 273 515 331 273 515 331 273 515 331 nCohort 2 53 34 31 48 31 29 33 25 17

Cutoff 1 0.500 0.609 0.275 0.463 0.541 0.235 0.542 0.547 0.532 Sens 1 72% 71% 71% 71% 71% 72% 73% 72% 71% Spec 1 0% 5% 0% 0% 3% 0% 1% 3% 1%

Cutoff 2 0.333 0.532 0.235 0.244 0.524 0.112 0.521 0.541 0.442 Sens 2 81% 82% 81% 81% 81% 83% 82% 80% 82% Spec 2 0% 3% 0% 0% 3% 0% 1% 3% 0%

Cutoff 3 0.117 0.450 0.0625 0.107 0.450 0.0952 0.442 0.460 0.143 Sens 3 91% 91% 90% 92% 90% 93% 91% 92% 94% Spec 3 0% 2% 0% 0% 2% 0% 0% 2% 0%

Cutoff 4 4.00 3.50 4.00 4.00 3.50 4.00 4.00 3.50 4.00 Sens 4 17% 26% 10% 19% 29% 10% 24% 32% 18% Spec 4 72% 70% 71% 72% 70% 71% 72% 70% 71%

Cutoff 5 5.20 4.28 5.30 5.20 4.28 5.30 5.20 4.28 5.30 Sens 5 13% 24% 10% 15% 26% 10% 18% 28% 18% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 7.06 6.20 7.18 7.06 6.20 7.18 7.06 6.20 7.18 Sens 6 4% 6% 0% 4% 6% 0% 6% 8% 0% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 0.53 0.36 1.0 0.42 0.12 1.0 0.61 0.27 0.66 p Value 0.28 0.14 0.99 0.17 0.047 1.0 0.40 0.11 0.65 95% CI of 0.17 0.094 0.20 0.12 0.015 0.20 0.19 0.056 0.11 OR Quart2 1.7 1.4 5.1 1.4 0.97 5.1 1.9 1.3 4.0

OR Quart 3 0.42 0.49 0.33 0.42 0.61 0.33 0.35 0.56 0.66 p Value 0.16 0.25 0.34 0.17 0.40 0.34 0.13 0.36 0.65 95% CI of 0.12 0.14 0.033 0.12 0.19 0.033 0.089 0.16 0.11 OR Quart3 1.4 1.7 3.2 1.4 1.9 3.2 1.4 2.0 4.0

OR Quart 4 6.2 2.6 11 5.1 2.3 9.4 2.5 1.8 3.6 p Value 1.4E-5 0.029 1.9E-4 1.2E-4 0.062 4.3E-4 0.050 0.24 0.057 95% CI of 2.7 1.1 3.1 2.2 0.96 2.7 1.0 0.68 0.96 OR Quart4 14 6.2 37 12 5.5 33 6.2 4.7 14

Insulin-like growth factor-binding protein 7 / (Weight Adjusted Urine Output)

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 317 477 317 477 317 400

Average 516000 4770000 516000 2390000 516000 2970000

Stdev 2370000 1.34E7 2370000 8500000 2370000 9410000 p(t-test) 4.2E-9 9.3E-4 1.0E-4

Min 13.9 80.5 13.9 103 13.9 66.2

Max 2.49E7 6.00E7 2.49E7 3.83E7 2.49E7 3.83E7 n (Samp) 515 34 515 31 515 25 n (Patient) 515 34 515 31 515 25

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 224 3430 224 1860 224 972

Average 304000 7390000 304000 5940000 304000 2670000

Stdev 1520000 1.67E7 1520000 1.63E7 1520000 9340000 p(t-test) 5.0E-13 2.8E-9 1.6E-4

Min 14.1 7.84 14.1 7.84 14.1 7.84

Max 1.26E7 5.86E7 1.26E7 5.86E7 1.26E7 3.83E7 n (Samp) 331 31 331 29 331 17 n (Patient) 331 31 331 29 331 17

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only p Value 0.72 0.17 0.56 0.47 0.99 0.57 0.75 0.74 1.0 95% CI of 0.20 0.064 0.044 0.39 0.24 0.044 0.32 0.21 0.14 OR Quart2 3.0 1.6 5.5 7.4 4.1 5.6 4.8 3.0 7.3

OR Quart 3 2.6 1.9 0.49 3.7 2.3 0.49 1.5 1.4 0.49 p Value 0.081 0.22 0.57 0.056 0.17 0.57 0.52 0.56 0.57 95% CI of 0.89 0.68 0.044 0.97 0.70 0.044 0.42 0.44 0.044 OR Quart3 7.9 5.3 5.6 14 7.8 5.6 5.7 4.6 5.6

OR Quart 4 9.7 2.7 19 15 3.8 17 5.5 1.9 6.8 p Value 9.7E-6 0.050 1.0E-4 1.7E-5 0.023 1.7E-4 0.0033 0.28 0.014 95% CI of 3.6 1.0 4.3 4.4 1.2 3.9 1.8 0.61 1.5 OR Quart4 27 7.1 81 52 12 74 17 5.7 31

Metalloproteinase inhibitor 2 / (Weight Adjusted Urine Output)

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

AUC 0.79 0.66 0.86 0.77 0.66 0.84 0.69 0.58 0.77

SE 0.039 0.052 0.043 0.041 0.055 0.046 0.053 0.061 0.068

P 5.7E-14 0.0021 0 3.8E-11 0.0045 1.5E-13 3.5E-4 0.18 6.4E-5 nCohort 1 273 515 331 273 515 331 273 515 331 nCohort 2 53 34 31 48 31 29 33 25 17

Cutoff 1 19.5 18.5 95.7 19.5 18.5 33.1 11.3 11.3 19.3 Sens 1 72% 71% 71% 71% 71% 72% 73% 72% 71% Spec 1 81% 60% 95% 81% 60% 89% 56% 37% 80%

Cutoff 2 11.5 11.3 48.2 11.3 11.3 22.9 6.22 8.38 16.5 Sens 2 81% 82% 81% 81% 81% 83% 82% 80% 82% Spec 2 57% 37% 93% 56% 37% 83% 30% 26% 74%

Cutoff 3 6.00 5.99 9.98 5.99 5.99 6.54 5.18 5.18 6.22 Sens 3 91% 91% 90% 92% 90% 93% 91% 92% 94% Spec 3 27% 17% 49% 27% 17% 31% 23% 14% 30%

Cutoff 4 15.0 25.7 15.0 15.0 25.7 15.0 15.0 25.7 15.0 Sens 4 79% 50% 87% 75% 48% 86% 67% 40% 82% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 19.1 38.7 19.3 19.1 38.7 19.3 19.1 38.7 19.3 Sens 5 72% 38% 84% 71% 42% 83% 58% 32% 71% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 33.8 88.5 37.9 33.8 88.5 37.9 33.8 88.5 37.9 Sens 6 58% 29% 81% 52% 32% 66% 36% 20% 41% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 0.64 0.49 3.0 0.79 0.79 3.1 1.2 0.79 2.0 p Value 0.50 0.32 0.34 0.73 0.73 0.34 0.75 0.74 0.57 95% CI of 0.17 0.12 0.31 0.20 0.21 0.31 0.32 0.21 0.18 OR Quart2 2.4 2.0 30 3.1 3.0 30 4.8 3.0 23

OR Quart 3 1.2 1.5 1.0 1.2 1.4 1.0 1.0 1.4 2.0 p Value 0.77 0.43 1.0 0.76 0.56 1.0 1.0 0.56 0.57 95% CI of 0.38 0.53 0.062 0.36 0.44 0.062 0.24 0.44 0.18 OR Quart3 3.7 4.4 16 4.2 4.6 16 4.2 4.6 23

OR Quart 4 9.8 2.9 36 10 3.2 32 6.3 1.9 14 p Value 1.9E-6 0.034 5.4E-4 5.7E-6 0.028 7.7E-4 0.0014 0.28 0.013 95% CI of 3.8 1.1 4.7 3.8 1.1 4.3 2.0 0.61 1.7 OR Quart4 25 7.6 270 28 9.1 250 20 5.7 110

Insulin-like growth factor-binding protein 7 X Serum Creatinine

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 115 420 115 341 115 285

Average 150 490 150 419 150 314

Stdev 126 340 126 270 126 207 p(t-test) 5.4E-34 5.6E-24 1.6E-9

Min 7.34 66.8 7.34 66.8 7.34 66.8

Max 973 1420 973 1100 973 950 n (Samp) 517 34 517 31 517 25 n (Patient) 517 34 517 31 517 25

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 99.8 446 99.8 386 99.8 247

Average 133 628 133 483 133 259

Stdev 115 576 115 442 115 171 p(t-test) 9.0E-33 4.5E-24 2.3E-5

Min 7.34 97.4 7.34 64.2 7.34 33.7

Max 869 2490 869 1820 869 687 n (Samp) 330 31 330 29 330 17 n (Patient) 330 31 330 29 330 17

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

95% CI of 0.45 0.31 >0.18 0.14 0.18 0.061 0.18 0.18 0.061 OR Quart2 38 29 na 7.2 22 16 23 22 16

OR Quart 3 7.5 2.0 >4.2 3.7 2.0 5.2 8.7 6.2 4.1 p Value 0.063 0.57 <0.20 0.11 0.57 0.14 0.044 0.092 0.21 95% CI of 0.90 0.18 >0.46 0.75 0.18 0.59 1.1 0.74 0.45 OR Quart3 62 22 na 19 22 45 71 52 37

OR Quart 4 80 35 >34 33 32 28 30 18 12 p Value 2.1E-5 5.5E-4 <6.3E-4 3.3E-6 7.5E-4 0.0012 0.0010 0.0055 0.018 95% CI of 11 4.6 >4.5 7.5 4.3 3.7 3.9 2.3 1.6 OR Quart4 600 260 na 140 240 220 230 140 98

Metalloproteinase inhibitor 2 X Serum Creatinine

sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

AUC 0.88 0.86 0.89 0.87 0.85 0.87 0.79 0.79 0.78

SE 0.031 0.041 0.038 0.034 0.044 0.043 0.048 0.055 0.068

P 0 0 0 0 1.8E-15 0 2.8E-9 2.2E-7 4.8E-5 nCohort 1 274 517 330 274 517 330 274 517 330 nCohort 2 53 34 31 48 31 29 33 25 17

Cutoff 1 9.84 12.1 14.3 9.77 9.80 12.6 6.38 7.11 7.47 Sens 1 72% 71% 71% 71% 71% 72% 73% 72% 71% Spec 1 92% 90% 94% 92% 85% 94% 73% 68% 80%

Cutoff 2 7.73 8.45 7.87 7.68 8.45 7.87 4.91 6.38 5.21 Sens 2 81% 82% 81% 81% 81% 83% 82% 80% 82% Spec 2 82% 76% 82% 82% 76% 82% 58% 61% 59%

Cutoff 3 5.14 5.14 6.02 3.79 5.74 3.63 3.63 4.61 2.70 Sens 3 91% 91% 90% 92% 90% 93% 91% 92% 94% Spec 3 62% 49% 66% 41% 55% 35% 38% 42% 19%

Cutoff 4 6.07 7.47 6.38 6.07 7.47 6.38 6.07 7.47 6.38 Sens 4 85% 85% 87% 83% 84% 86% 76% 68% 76% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 7.26 9.01 7.47 7.26 9.01 7.47 7.26 9.01 7.47 Sens 5 83% 79% 87% 81% 74% 86% 64% 64% 71% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 9.13 12.9 10.2 9.13 12.9 10.2 9.13 12.9 10.2 Sens 6 75% 68% 74% 73% 65% 76% 58% 48% 53% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.5 3.0 1.0 0.65 2.0 0.49 0.99 3.0 0.49 p Value 0.66 0.34 1.0 0.64 0.57 0.56 0.99 0.34 0.56 95% CI of 0.24 0.31 0.062 0.11 0.18 0.044 0.19 0.31 0.043 OR Quart2 9.2 29 16 4.0 22 5.5 5.0 29 5.5

OR Quart 3 4.3 3.0 2.0 2.1 4.1 0.49 2.1 5.2 0.49 p Value 0.072 0.34 0.57 0.31 0.21 0.56 0.32 0.14 0.56 95% CI of 0.88 0.31 0.18 0.50 0.45 0.044 0.50 0.59 0.043 OR Quart3 21 29 23 8.6 37 5.5 8.5 45 5.5

OR Quart 4 38 33 38 22 29 17 9.1 18 7.4 p Value 1.3E-6 6.5E-4 4.4E-4 1.1E-6 0.0011 1.8E-4 5.8E-4 0.0055 0.010 95% CI of 8.7 4.4 5.0 6.3 3.8 3.8 2.6 2.3 1.6 OR Quart4 160 250 280 74 220 73 32 140 34

Insulin-like growth factor-binding protein 7 X Serum Creatinine / (Weight Adjusted Urine Output)

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Cutoff 3 113 113 427 102 319 242 102 102 72.3 Sens 3 91% 91% 90% 92% 90% 93% 91% 92% 94% Spec 3 37% 23% 83% 32% 58% 66% 32% 19% 19%

Cutoff 4 253 447 265 253 447 265 253 447 265 Sens 4 85% 74% 90% 85% 71% 86% 76% 56% 76% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 351 805 380 351 805 380 351 805 380 Sens 5 81% 56% 90% 79% 52% 83% 61% 40% 71% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 646 1840 744 646 1840 744 646 1840 744 Sens 6 68% 29% 87% 58% 29% 79% 39% 16% 53% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.0 0.24 0 0.66 0 0 1.0 0 0 p Value 1.0 0.21 na 0.65 na na 1.0 na na 95% CI of 0.20 0.027 na 0.11 na na 0.20 na na OR Quart2 5.1 2.2 na 4.0 na na 5.1 na na

OR Quart 3 2.1 2.3 0.49 2.9 4.3 1.5 2.1 2.6 1.5 p Value 0.31 0.17 0.57 0.13 0.027 0.66 0.31 0.11 0.66 95% CI of 0.50 0.70 0.044 0.73 1.2 0.24 0.50 0.79 0.24 OR Quart3 8.6 7.8 5.6 11 16 9.2 8.7 8.5 9.2

OR Quart 4 26 5.7 20 20 5.9 16 9.1 2.9 6.7 p Value 2.2E-7 0.0020 7.4E-5 2.0E-6 0.0058 2.5E-4 5.8E-4 0.076 0.015 95% CI of 7.6 1.9 4.5 5.8 1.7 3.6 2.6 0.89 1.5 OR Quart4 89 17 85 69 21 69 32 9.3 31

Metalloproteinase inhibitor 2 X Serum Creatinine / (Weight Adjusted Urine Output)

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 7.38 332 7.38 196 7.38 53.5

Average 12800 1210000 12800 554000 12800 399000

Stdev 65500 2700000 65500 1400000 65500 1350000 p(t-test) 5.5E-15 1.2E-11 3.3E-7

Min 0.348 0.563 0.348 0.563 0.348 0.563

Max 548000 9440000 548000 5510000 548000 5510000 n (Samp) 330 31 330 29 330 17 n (Patient) 330 31 330 29 330 17

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

Sens 3 91% 91% 90% 92% 90% 93% 91% 92% 94% Spec 3 49% 38% 31% 47% 38% 25% 19% 14% 25%

Cutoff 4 1.28 1.59 1.28 1.28 1.59 1.28 1.28 1.59 1.28 Sens 4 77% 68% 81% 75% 65% 72% 61% 56% 59% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 1.61 2.11 1.66 1.61 2.11 1.66 1.61 2.11 1.66 Sens 5 72% 50% 74% 62% 45% 62% 52% 40% 53% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 2.19 2.99 2.36 2.19 2.99 2.36 2.19 2.99 2.36 Sens 6 55% 44% 58% 44% 39% 45% 36% 32% 41% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.0 1.0 0.32 1.3 1.5 0.33 0.74 0.66 0.49 p Value 1.0 1.0 0.33 0.71 0.65 0.34 0.70 0.65 0.57 95% CI of 0.24 0.20 0.033 0.29 0.25 0.033 0.16 0.11 0.044 OR Quart2 4.1 5.0 3.2 6.2 9.2 3.2 3.4 4.0 5.6

OR Quart 3 2.7 2.4 1.3 4.5 5.3 2.4 2.4 2.8 2.6 p Value 0.10 0.21 0.70 0.025 0.033 0.21 0.16 0.14 0.26 95% CI of 0.81 0.61 0.29 1.2 1.1 0.61 0.71 0.71 0.49 OR Quart3 9.0 9.5 6.2 16 25 9.8 8.2 11 14

OR Quart 4 15 8.1 9.8 14 8.9 7.2 5.2 4.3 4.9 p Value 1.7E-6 9.1E-4 3.2E-4 2.6E-5 0.0041 0.0021 0.0048 0.028 0.046 95% CI of 4.9 2.3 2.8 4.1 2.0 2.1 1.7 1.2 1.0 OR Quart4 43 28 34 49 39 26 16 15 23

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 X

Serum Creatinine

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2 n (Samp) 517 34 517 31 517 25 n (Patient) 517 34 517 31 517 25

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 0.588 5.68 0.588 4.59 0.588 2.09

Average 1.02 12.2 1.02 7.59 1.02 3.41

Stdev 1.52 13.3 1.52 8.54 1.52 3.08 p(t-test) 6.6E-38 1.4E-28 7.2E-9

Min 0.0244 0.438 0.0244 0.355 0.0244 0.0404

Max 14.6 53.4 14.6 31.2 14.6 10.6 n (Samp) 330 31 330 29 330 17 n (Patient) 330 31 330 29 330 17

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

OR Quart 4 >81 32 >34 >71 >29 >31 32 >19 14 p Value <2.0E-5 7.8E-4 <6.3E-4 <3.6E-5 <0.0010 <9.5E-4 8.4E-4 <0.0043 0.013 95% CI of >11 4.2 >4.5 >9.4 >3.9 >4.0 4.2 >2.5 1.7 OR Quart4 na 240 na na na na 240 na 110

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 /

(Weight Adjusted Urine Output)

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only nCohort 2 53 34 31 48 31 29 33 25 17

Cutoff 1 3.62 3.55 16.1 3.55 3.55 5.84 1.82 1.84 2.96 Sens 1 72% 71% 71% 71% 71% 72% 73% 72% 71% Spec 1 82% 67% 95% 82% 67% 89% 68% 52% 77%

Cutoff 2 1.94 1.48 5.84 2.47 1.48 3.45 0.829 0.998 1.82 Sens 2 81% 82% 81% 81% 81% 83% 82% 80% 82% Spec 2 69% 44% 89% 75% 44% 79% 40% 31% 66%

Cutoff 3 0.778 0.704 2.63 0.778 0.778 0.829 0.242 0.242 0.778 Sens 3 91% 91% 90% 92% 90% 93% 91% 92% 94% Spec 3 37% 23% 75% 37% 25% 40% 12% 7% 37%

Cutoff 4 2.10 4.14 2.15 2.10 4.14 2.15 2.10 4.14 2.15 Sens 4 79% 59% 90% 81% 61% 90% 70% 48% 76% Spec 4 70% 70% 70% 70% 70% 70% 70% 70% 70%

Cutoff 5 3.24 7.73 3.49 3.24 7.73 3.49 3.24 7.73 3.49 Sens 5 75% 41% 84% 73% 42% 79% 55% 32% 65% Spec 5 80% 80% 80% 80% 80% 80% 80% 80% 80%

Cutoff 6 5.84 18.6 7.04 5.84 18.6 7.04 5.84 18.6 7.04 Sens 6 57% 29% 77% 52% 32% 66% 30% 20% 47% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.7 0.39 2.0 1.7 0.74 2.0 0.99 0.74 2.0 p Value 0.48 0.27 0.57 0.47 0.70 0.57 0.98 0.70 0.57 95% CI of 0.39 0.075 0.18 0.39 0.16 0.18 0.24 0.16 0.18 OR Quart2 7.3 2.1 22 7.4 3.4 23 4.1 3.4 23

OR Quart 3 3.2 2.3 2.0 2.9 2.3 3.1 1.3 2.3 2.0 p Value 0.086 0.13 0.57 0.13 0.17 0.34 0.73 0.17 0.57 95% CI of 0.85 0.78 0.18 0.73 0.70 0.31 0.33 0.70 0.18 OR Quart3 12 6.8 23 11 7.8 30 4.9 7.8 23

OR Quart 4 20 3.5 36 17 4.1 31 6.3 2.3 14 p Value 1.7E-6 0.019 5.4E-4 7.9E-6 0.015 9.5E-4 0.0014 0.17 0.013 95% CI of 5.9 1.2 4.7 4.9 1.3 4.0 2.0 0.70 1.7 OR Quart4 70 9.7 270 58 13 230 20 7.8 110

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 X

Serum Creatinine / (Weight Adjusted Urine Output)

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 1.42 9.33 1.42 9.35 1.42 4.97

Average 1940 290000 1940 110000 1940 137000

Stdev 10700 877000 10700 465000 10700 517000 p(t-test) 2.1E-13 1.4E-7 3.6E-9

Min 0.0182 0.242 0.0182 0.242 0.0182 0.242

Max 151000 3800000 151000 2550000 151000 2550000 n (Samp) 514 34 514 31 514 25 n (Patient) 514 34 514 31 514 25

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 0.867 84.7 0.867 42.1 0.867 9.72

Average 911 359000 911 189000 911 51300

Stdev 5220 853000 5220 580000 5220 146000 p(t-test) 1.2E-13 5.2E-9 6.1E-10

Min 0.0182 0.0134 0.0182 0.0134 0.0182 0.0134

Max 58400 2640000 58400 2500000 58400 486000 n (Samp) 330 31 330 29 330 17 n (Patient) 330 31 330 29 330 17

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

95% CI of 0.29 0.027 0.062 0.20 0.034 0.061 0.29 0.088 0.061 OR Quart2 6.2 2.2 16 5.1 3.2 16 6.3 2.7 16

OR Quart 3 1.4 1.5 2.0 2.1 2.8 4.1 1.0 1.5 3.0 p Value 0.70 0.52 0.57 0.31 0.14 0.21 1.0 0.53 0.34 95% CI of 0.29 0.42 0.18 0.50 0.72 0.45 0.20 0.42 0.31 OR Quart3 6.2 5.5 23 8.6 11 37 5.1 5.5 30

OR Quart 4 27 6.7 38 21 7.1 30 10 3.5 14 p Value 1.4E-7 6.3E-4 4.4E-4 1.3E-6 0.0019 9.8E-4 2.6E-4 0.034 0.013 95% CI of 8.0 2.3 5.0 6.1 2.1 4.0 3.0 1.1 1.7 OR Quart4 94 20 280 72 25 230 36 11 110

Serum Creatinine

sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

AUC 0.85 0.87 0.85 0.80 0.83 0.80 0.74 0.76 0.71

SE 0.034 0.040 0.044 0.040 0.046 0.050 0.051 0.057 0.072

P 0 0 2.2E-15 1.6E-14 1.3E-12 3.1E-9 2.1E-6 6.8E-6 0.0033 nCohort 1 275 518 331 275 518 331 275 518 331 nCohort 2 53 34 31 48 31 29 33 25 17

Cutoff 1 1.44 1.58 1.45 1.20 1.36 1.44 0.980 1.09 0.980 Sens 1 74% 71% 71% 71% 71% 72% 76% 72% 71% Spec 1 88% 88% 86% 81% 82% 85% 63% 66% 60%

Cutoff 2 1.09 1.19 1.15 0.970 1.09 0.970 0.880 0.990 0.800 Sens 2 83% 82% 81% 81% 81% 83% 82% 84% 82% Spec 2 72% 73% 74% 62% 66% 59% 48% 57% 39%

Cutoff 3 0.890 0.890 0.900 0.750 0.910 0.590 0.660 0.880 0.590 Sens 3 91% 94% 90% 92% 90% 93% 91% 92% 94% Spec 3 49% 45% 52% 37% 51% 17% 28% 44% 17%

Cutoff 4 1.04 1.10 1.10 1.04 1.10 1.10 1.04 1.10 1.10 Sens 4 83% 82% 81% 75% 77% 76% 67% 68% 65% Spec 4 70% 70% 72% 70% 70% 72% 70% 70% 72%

Cutoff 5 1.20 1.30 1.33 1.20 1.30 1.33 1.20 1.30 1.33 Sens 5 75% 79% 74% 71% 71% 72% 58% 56% 65% Spec 5 81% 80% 80% 81% 80% 80% 81% 80% 80%

Cutoff 6 1.54 1.70 1.58 1.54 1.70 1.58 1.54 1.70 1.58 Sens 6 64% 68% 65% 60% 52% 66% 39% 32% 35% Spec 6 90% 90% 90% 90% 90% 90% 90% 90% 90%

OR Quart 2 1.7 3.0 0.99 0.99 3.0 0.66 1.7 3.0 1.5 p Value 0.47 0.34 0.99 0.99 0.34 0.65 0.47 0.34 0.65 95% CI of 0.39 0.31 0.14 0.24 0.31 0.11 0.39 0.31 0.25 OR Quart2 7.4 30 7.2 4.1 30 4.0 7.4 29 9.3

OR Quart 3 2.1 3.0 2.0 2.1 4.1 1.0 1.7 6.2 0.49 p Value 0.31 0.34 0.42 0.25 0.21 1.0 0.47 0.094 0.57 95% CI of 0.50 0.31 0.37 0.60 0.45 0.20 0.39 0.73 0.044 OR Quart3 8.6 30 11 7.2 37 5.1 7.4 52 5.6

OR Quart 4 24 33 15 12 27 8.8 8.7 17 6.2 p Value 4.4E-7 6.3E-4 3.5E-4 7.2E-6 0.0013 6.4E-4 8.0E-4 0.0069 0.021 95% CI of 7.0 4.5 3.4 4.1 3.6 2.5 2.5 2.2 1.3 OR Quart4 82 250 65 37 200 31 31 130 29

Serum Creatinine / (Weight Adjusted Urine Output)

sCr only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 2.36 5.82 2.36 4.57 2.36 3.87

Average 4820 30600 4820 18800 4820 23200

Stdev 21200 93900 21200 66700 21200 73800 p(t-test) 3.2E-6 0.0037 5.6E-4

Min 0.104 0.407 0.104 0.407 0.104 0.407

Max 180000 421000 180000 330000 180000 330000 n (Samp) 514 34 514 31 514 25 n (Patient) 514 34 514 31 514 25

UO only Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage

Cohort 1 Cohort 2 Cohort 1 Cohort 2 Cohort 1 Cohort 2

Median 1.60 21.6 1.60 14.4 1.60 4.65

Average 4090 57700 4090 35800 4090 14800

Stdev 21400 128000 21400 97900 21400 44500 p(t-test) 5.4E-11 2.6E-6 0.063

Min 0.104 0.469 0.104 0.469 0.104 0.469

Max 230000 431000 230000 431000 230000 170000 n (Samp) 330 31 330 29 330 17 n (Patient) 330 31 330 29 330 17

Ohr prior to AKI stage 24hr prior to AKI stage 48hr prior to AKI stage sCr or UO sCr only UO only sCr or UO sCr only UO only sCr or UO sCr only UO only

95% CI of 0.24 0.24 0.044 0.16 0.50 0.044 0.24 0.60 0.043 OR Quart2 4.1 4.1 5.6 3.4 8.4 5.5 4.2 9.4 5.5

OR Quart 3 1.8 1.8 0 2.4 2.0 0.99 2.1 1.7 1.5 p Value 0.35 0.36 na 0.16 0.32 0.99 0.24 0.48 0.66 95% CI of 0.51 0.51 na 0.71 0.50 0.14 0.61 0.39 0.24 OR Quart3 6.5 6.3 na 8.2 8.4 7.2 7.4 7.2 9.2

OR Quart 4 17 5.4 20 13 5.9 16 5.1 3.5 6.1 p Value 4.9E-7 0.0030 7.4E-5 6.1E-6 0.0058 2.5E-4 0.0052 0.062 0.021 95% CI of 5.6 1.8 4.5 4.2 1.7 3.6 1.6 0.94 1.3 OR Quart4 50 16 85 38 21 69 16 13 28

[0115] Table 4: Comparison of marker levels in samples collected within 12 hours of reaching stage R from Cohort 1 (patients that reached, but did not progress beyond,

RIFLE stage R) and from Cohort 2 (patients that reached RIFLE stage I or F). Insulinlike growth factor-binding protein 7 and Metalloproteinase inhibitor 2 were measured in urine.

Insulin-like growth factor-binding protein 7

OR Quart4 7.9 7.2 7.3

Metalloproteinase inhibitor 2

OR Quart4 8.5 7.3 6.2

Weight Adjusted Urine Output

OR Quart4 6.8 2.7 13

Insulin-like growth factor-binding protein 7 / (Weight Adjusted Urine Output)

Metalloproteinase inhibitor 2 / (Weight Adjusted Urine Output)

OR Quart4 9.6 5.1 11

Insulin-like growth factor-binding protein 7 X Serum Creatinine

At Enrollment

OR Quart4 10 11 10

Metalloproteinase inhibitor 2 X Serum Creatinine

OR Quart4 9.3 15 8.3

Insulin-like growth factor-binding protein 7 X Serum Creatinine / (Weight Adjusted Urine Output)

Metalloproteinase inhibitor 2 X Serum Creatinine / (Weight Adjusted Urine Output)

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 X Serum Creatinine

OR Quart4 12 15 7.8

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 / (Weight Adjusted Urine Output)

OR Quart4 11 6.5 12

Insulin-like growth factor-binding protein 7 X Metalloproteinase inhibitor 2 X Serum Creatinine / (Weight Adjusted Urine Output)

OR Quart4 15 11 11

Serum Creatinine

OR Quart4 5.8 9.7 4.8

Serum Creatinine / (Weight Adjusted Urine Output)

OR Quart4 14 14 12

[0116] While the invention has been described and exemplified in sufficient detail for those skilled in this art to make and use it, various alternatives, modifications, and improvements should be apparent without departing from the spirit and scope of the invention. The examples provided herein are representative of preferred embodiments, are exemplary, and are not intended as limitations on the scope of the invention.

Modifications therein and other uses will occur to those skilled in the art. These modifications are encompassed within the spirit of the invention and are defined by the scope of the claims.

[0117] It will be readily apparent to a person skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention.

[0118] All patents and publications mentioned in the specification are indicative of the levels of those of ordinary skill in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.

[0119] The invention illustratively described herein suitably may be practiced in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein. Thus, for example, in each instance herein any of the terms "comprising", "consisting essentially of and "consisting of may be replaced with either of the other two terms. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention that in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.

[0120] Other embodiments are set forth within the following claims.

Claims

We claim:

1. A method for evaluating renal status in a subject, comprising:

determining a measured value for one or more of a urine TIMP2 concentration and a urine IGFBP7 concentration;

determining a measured value for one or more of a serum creatinine concentration and a urine output;

combining the measured values obtained into a single value to provide an assay result; and

correlating the assay result to the renal status of the subject, wherein said correlation step comprises correlating the assay result(s) to one or more of diagnosis, risk stratification, prognosis, classifying and monitoring of the renal status of the subject.

2. A method according to claim 1 , wherein said correlation step comprises correlating the assay result to prognosis of the renal status of the subject.

3. A method according to claim 1, wherein said correlating step comprises assigning a likelihood of one or more future changes in renal status to the subject based on the assay result.

4. A method according to claim 3, wherein said one or more future changes in renal status comprise one or more of a future injury to renal function, future reduced renal function, future improvement in renal function, and future acute renal failure (ARF).

5. A method according to one of claims 1-4, wherein the single value is calculated as urine TIMP2 x urine IGFBP7 x serum creatinine; urine TIMP2 x urine IGFBP7 / urine output; urine TIMP2 x urine IGFBP7 x serum creatinine / urine output; urine TIMP2 x serum creatinine; urine TIMP2 / urine output; urine TIMP2 x serum creatinine / urine output; urine IGFBP7 x serum creatinine; urine IGFBP7 / urine output; or urine IGFBP7 x serum creatinine / urine output.

6. A method according to one of claims 1-5, wherein the correlation step comprises correlating the assay result to a diagnosis of acute renal failure or an injury to renal function.

7. A method according to one of claims 1-5, wherein the correlation step comprises correlating the assay result to a likelihood of a clinical outcome related to a renal injury suffered by the subject.

8. A method according to one of claims 1-5, wherein the correlation step comprises correlating the assay result to a likelihood of one or more future changes in renal status occurring within 30 days of the time at which the body fluid sample is obtained from the subject.

9. A method according to claim 8, wherein the likelihood of one or more future changes in renal status is that an event of interest is more or less likely to occur within a period selected from the group consisting of 21 days, 14 days, 7 days, 5 days, 96 hours, 72 hours, 48 hours, 36 hours, 24 hours, and 12 hours.

10. A method according to one of claims 1-9, wherein the subject is selected for evaluation of renal status based on the pre-existence in the subject of one or more known risk factors for prerenal, intrinsic renal, or postrenal ARF.

11. A method according to one of claims 1-9, wherein the subject is selected for evaluation of renal status based on an existing diagnosis of one or more of congestive heart failure, preeclampsia, eclampsia, diabetes mellitus, hypertension, coronary artery disease, proteinuria, renal insufficiency, glomerular filtration below the normal range, cirrhosis, serum creatinine above the normal range, sepsis, injury to renal function, reduced renal function, or ARF, or based on undergoing or having undergone major vascular surgery, coronary artery bypass, or other cardiac surgery, or based on exposure to NSAIDs, cyclosporines, tacrolimus, aminoglycosides, foscarnet, ethylene glycol, hemoglobin, myoglobin, ifosfamide, heavy metals, methotrexate, radiopaque contrast agents, or streptozotocin.

12. A method according to one of claims 1-9, wherein said correlating step comprises assessing whether or not renal function is improving or worsening in a subject who has suffered from an injury to renal function, reduced renal function, or ARF based on the assay result.

13. A method according to one of claims 1-9, wherein said method is a method of assigning a risk of the future occurrence or nonoccurrence of an injury to renal function in said subject.

14. A method according to one of claims 1-9, wherein said method is a method of assigning a risk of the future occurrence or nonoccurrence of reduced renal function in said subject.

15. A method according to one of claims 1-9, wherein said method is a method of assigning a risk of the future occurrence or nonoccurrence of a need for dialysis in said subject.

16. A method according to one of claims 1-9, wherein said method is a method of assigning a risk of the future occurrence or nonoccurrence of acute renal failure in said subject.

17. A method according to one of claims 1-9, wherein said method is a method of assigning a risk of the future occurrence or nonoccurrence of a need for renal replacement therapy in said subject.

18. A method according to one of claims 1-9, wherein said method is a method of assigning a risk of the future occurrence or nonoccurrence of a need for renal

transplantation in said subject.

19. A method according to one of claims 1-9, wherein said one or more future changes in renal status comprise one or more of a future injury to renal function, future reduced renal function, future improvement in renal function, and future acute renal failure (ARF) within 72 hours of the time at which the body fluid sample is obtained.

20. A method according to one of claims 1-9, wherein said one or more future changes in renal status comprise one or more of a future injury to renal function, future reduced renal function, future improvement in renal function, and future acute renal failure (ARF) within 48 hours of the time at which the body fluid sample is obtained.

21. A method according to one of claims 1-9, wherein said one or more future changes in renal status comprise one or more of a future injury to renal function, future reduced renal function, future improvement in renal function, and future acute renal failure (ARF) within 24 hours of the time at which the body fluid sample is obtained.

22. A method according to one of claims 1-9, wherein the subject is in RIFLE stage 0 or R.

23. A method according to claim 22, wherein the subject is in RIFLE stage 0, and said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage R, I or F within 72 hours.

24. A method according to claim 23, wherein the subject is in RIFLE stage 0, and said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage I or F within 72 hours.

25. A method according to claim 23, wherein the subject is in RIFLE stage 0, and said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 72 hours.

26. A method according to claim 22, wherein the subject is in RIFLE stage 0 or R, and said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage I or F within 72 hours.

27. A method according to claim 26, wherein the subject is in RIFLE stage 0 or R, and said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 72 hours.

28. A method according to claim 22, wherein the subject is in RIFLE stage R, and said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage I or F within 72 hours.

29. A method according to claim 28, wherein the subject is in RIFLE stage R, and said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 72 hours.

30. A method according to one of claims 1-9, wherein the subject is in RIFLE stage 0, R, or I, and said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 72 hours.

31. A method according to claim 30, wherein the subject is in RIFLE stage I, and said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 72 hours.

32. A method according to claim 23, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage R, I or F within 48 hours.

33. A method according to claim 24, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage I or F within 48 hours.

34. A method according to claim 25, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 48 hours.

35. A method according to claim 26, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage I or F within 48 hours.

36. A method according to claim 27, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 48 hours.

37. A method according to claim 28, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage I or F within 48 hours.

38. A method according to claim 29, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 48 hours.

39. A method according to claim 30, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 48 hours.

40. A method according to claim 31 , wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 48 hours.

41. A method according to claim 23, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage R, I or F within 24 hours.

42. A method according to claim 24, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage I or F within 24 hours.

43. A method according to claim 25, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 24 hours.

44. A method according to claim 26, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage I or F within 24 hours.

45. A method according to claim 27, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 24 hours.

46. A method according to claim 28, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage I or F within 24 hours.

47. A method according to claim 29, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 24 hours.

48. A method according to claim 30, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 24 hours.

49. A method according to claim 31, wherein said correlating step comprises assigning a likelihood that the subject will reach RIFLE stage F within 24 hours.

50. A method according to one of claims 1-9, wherein the subject is not in acute renal failure.

51. A method according to one of claims 1-9, wherein the subject has not experienced a 1.5 -fold or greater increase in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained.

52. A method according to one of claims 1-9, wherein the subject has a urine output of at least 0.5 ml/kg/hr over the 6 hours preceding the time at which the body fluid sample is obtained.

53. A method according to one of claims 1-9, wherein the subject has not experienced an increase of 0.3 mg/dL or greater in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained.

54. A method according to one of claims 1-9, wherein the subject (i) has not experienced a 1.5 -fold or greater increase in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained, (ii) has a urine output of at least 0.5 ml/kg/hr over the 6 hours preceding the time at which the body fluid sample is obtained, and (iii) has not experienced an increase of 0.3 mg/dL or greater in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained.

55. A method according to one of claims 1-9, wherein the subject has not experienced a 1.5 -fold or greater increase in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained.

56. A method according to one of claims 1-9, wherein the subject has a urine output of at least 0.5 ml/kg/hr over the 6 hours preceding the time at which the body fluid sample is obtained.

57. A method according to one of claims 1-9, wherein the subject (i) has not experienced a 1.5 -fold or greater increase in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained, (ii) has a urine output of at least 0.5 ml/kg/hr over the 12 hours preceding the time at which the body fluid sample is obtained, and (iii) has not experienced an increase of 0.3 mg/dL or greater in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained.

58. A method according to one of claims 1-9, wherein said correlating step comprises assigning one or more of: a likelihood that within 72 hours the subject will (i) experience a 1.5 -fold or greater increase in serum creatinine (ii) have a urine output of less than 0.5 ml/kg/hr over a 6 hour period, or (iii) experience an increase of 0.3 mg/dL or greater in serum creatinine.

59. A method according to claim 58, wherein said correlating step comprises assigning one or more of: a likelihood that within 48 hours the subject will (i) experience a 1.5 -fold or greater increase in serum creatinine (ii) have a urine output of less than 0.5 ml/kg/hr over a 6 hour period, or (iii) experience an increase of 0.3 mg/dL or greater in serum creatinine.

60. A method according to claim 58, wherein said correlating step comprises assigning one or more of: a likelihood that within 24 hours the subject will (i) experience a 1.5 -fold or greater increase in serum creatinine (ii) have a urine output of less than 0.5 ml/kg/hr over a 6 hour period, or (iii) experience an increase of 0.3 mg/dL or greater in serum creatinine.

61. A method according to claim 58, wherein said correlating step comprises assigning a likelihood that within 72 hours the subject will experience a 1.5-fold or greater increase in serum creatinine.

62. A method according to claim 58, wherein said correlating step comprises assigning a likelihood that within 72 hours the subject will have a urine output of less than 0.5 ml/kg/hr over a 6 hour period.

63. A method according to claim 58, wherein said correlating step comprises assigning a likelihood that within 72 hours the subject will experience an increase of 0.3 mg/dL or greater in serum creatinine.

64. A method according to claim 58, wherein said correlating step comprises assigning a likelihood that within 48 hours the subject will experience a 1.5-fold or greater increase in serum creatinine.

65. A method according to claim 58, wherein said correlating step comprises assigning a likelihood that within 48 hours the subject will have a urine output of less than 0.5 ml/kg/hr over a 6 hour period.

66. A method according to claim 58, wherein said correlating step comprises assigning a likelihood that within 48 hours the subject will experience an increase of 0.3 mg/dL or greater in serum creatinine.

67. A method according to claim 58, wherein said correlating step comprises assigning a likelihood that within 24 hours the subject will experience a 1.5-fold or greater increase in serum creatinine.

68. A method according to claim 58, wherein said correlating step comprises assigning a likelihood that within 24 hours the subject will have a urine output of less than 0.5 ml/kg/hr over a 6 hour period.

69. A method according to claim 58, wherein said correlating step comprises assigning a likelihood that within 24 hours the subject will experience an increase of 0.3 mg/dL or greater in serum creatinine.

70. A method according to one of claims 1-9, wherein the subject has not experienced a 2-fold or greater increase in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained.

71. A method according to one of claims 1-9, wherein the subject has a urine output of at least 0.5 ml/kg/hr over the 12 hours preceding the time at which the body fluid sample is obtained.

72. A method according to one of claims 1-9, wherein the subject (i) has not experienced a 2-fold or greater increase in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained, (ii) has a urine output of at least 0.5 ml/kg/hr over the 2 hours preceding the time at which the body fluid sample is obtained, and (iii) has not experienced an increase of 0.3 mg/dL or greater in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained.

73. A method according to one of claims 1-9, wherein the subject has not experienced a 3 -fold or greater increase in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained.

74. A method according to one of claims 1-9, wherein the subject has a urine output of at least 0.3 ml/kg/hr over the 24 hours preceding the time at which the body fluid sample is obtained, or anuria over the 12 hours preceding the time at which the body fluid sample is obtained.

75. A method according to one of claims 1-9, wherein the subject (i) has not experienced a 3-fold or greater increase in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained, (ii) has a urine output of at least 0.3 ml/kg/hr over the 24 hours preceding the time at which the body fluid sample is obtained, or anuria over the 12 hours preceding the time at which the body fluid sample is obtained, and (iii) has not experienced an increase of 0.3 mg/dL or greater in serum creatinine over a baseline value determined prior to the time at which the body fluid sample is obtained.

76. A method according to one of claims 1-9, wherein said correlating step comprises assigning one or more of: a likelihood that within 72 hours the subject will (i) experience a 2-fold or greater increase in serum creatinine (ii) have a urine output of less than 0.5 ml/kg/hr over a 12 hour period, or (iii) experience an increase of 0.3 mg/dL or greater in serum creatinine.

77. A method according to claim 76, wherein said correlating step comprises assigning one or more of: a likelihood that within 48 hours the subject will (i) experience a 2-fold or greater increase in serum creatinine (ii) have a urine output of less than 0.5 ml/kg/hr over a 6 hour period, or (iii) experience an increase of 0.3 mg/dL or greater in serum creatinine.

78. A method according to claim 76, wherein said correlating step comprises assigning one or more of: a likelihood that within 24 hours the subject will (i) experience a 2-fold or greater increase in serum creatinine, or (ii) have a urine output of less than 0.5 ml/kg/hr over a 6 hour period.

79. A method according to claim 76, wherein said correlating step comprises assigning a likelihood that within 72 hours the subject will experience a 2-fold or greater increase in serum creatinine.

80. A method according to claim 76, wherein said correlating step comprises assigning a likelihood that within 72 hours the subject will have a urine output of less than 0.5 ml/kg/hr over a 6 hour period.

81. A method according to claim 76, wherein said correlating step comprises assigning a likelihood that within 48 hours the subject will experience a 2-fold or greater increase in serum creatinine.

82. A method according to claim 76, wherein said correlating step comprises assigning a likelihood that within 48 hours the subject will have a urine output of less than 0.5 ml/kg/hr over a 6 hour period.

83. A method according to claim 76, wherein said correlating step comprises assigning a likelihood that within 24 hours the subject will experience a 2-fold or greater increase in serum creatinine.

84. A method according to claim 76, wherein said correlating step comprises assigning a likelihood that within 24 hours the subject will have a urine output of less than 0.5 ml/kg/hr over a 6 hour period.

85. A method according to one of claims 1-9, wherein said correlating step comprises assigning one or more of: a likelihood that within 72 hours the subject will (i) experience a 3-fold or greater increase in serum creatinine, or (ii) have a urine output of less than 0.3 ml/kg/hr over a 24 hour period or anuria over a 12 hour period.

86. A method according to claim 85, wherein said correlating step comprises assigning one or more of: a likelihood that within 48 hours the subject will (i) experience a 3-fold or greater increase in serum creatinine, or (ii) have a urine output of less than 0.3 ml/kg/hr over a 24 hour period or anuria over a 12 hour period.

87. A method according to claim 85, wherein said correlating step comprises assigning one or more of: a likelihood that within 24 hours the subject will (i) experience a 3-fold or greater increase in serum creatinine, or (ii) have a urine output of less than 0.3 ml/kg/hr over a 24 hour period or anuria over a 12 hour period.

88. A method according to claim 85, wherein said correlating step comprises assigning a likelihood that within 72 hours the subject will experience a 3-fold or greater increase in serum creatinine.

89. A method according to claim 85, wherein said correlating step comprises assigning a likelihood that within 72 hours the subject will have a urine output of less than 0.3 ml/kg/hr over a 24 hour period or anuria over a 12 hour period.

90. A method according to claim 85, wherein said correlating step comprises assigning a likelihood that within 48 hours the subject will experience a 3-fold or greater increase in serum creatinine.

91. A method according to claim 85, wherein said correlating step comprises assigning a likelihood that within 48 hours the subject will have a urine output of less than 0.3 ml/kg/hr over a 24 hour period or anuria over a 12 hour period.

92. A method according to claim 85, wherein said correlating step comprises assigning a likelihood that within 24 hours the subject will experience a 3-fold or greater increase in serum creatinine.

93. A method according to claim 85, wherein said correlating step comprises assigning a likelihood that within 24 hours the subject will have a urine output of less than 0.3 ml/kg/hr over a 24 hour period or anuria over a 12 hour period.

94. A system for evaluating biomarker levels, comprising:

one or more reagents selected from the group consisting of a reagent which specifically binds TIMP2 and a reagent which specifically binds IGFBP7; and

an assay instrument configured to receive a urine sample and contact the one or more reagents with the urine sample and to generate one or more measured values resulting from binding of TIMP2 and/or IGFBP7 to a respective specific binding reagent in the one or more reagents, the measured values indicative of a TIMP2 concentration and/or a IGFBP7 concentration,

wherein the assay instrument is further configured to receive entry of, or determine, one or more measured values for one or more of a serum creatinine concentration and a urine output, and

wherein the assay instrument combines the measured values obtained by the instrument into a single value to provide an assay result.

95. A system according to claim 94, wherein the one or more reagents are selected from the group consisting of an antibody which specifically binds TIMP2 and an antibody which specifically binds IGFBP7.

96. A system according to claim 95, wherein assay instrument comprises an assay device and an assay device reader, wherein the one or more reagents are immobilized at one or more predetermined locations within the assay device, wherein the assay device is configured to receive the urine sample such that the urine sample contacts the one or more predetermined locations, and wherein the assay device reader interrogates the one or more predetermined locations to generate the measured values indicative of a TIMP2 concentration and/or a IGFBP7 concentration.

97. The system of one of claims 94-96, wherein the single value is calculated as urine TIMP2 x urine IGFBP7 x serum creatinine; urine TIMP2 x urine IGFBP7 / urine output; urine TIMP2 x urine IGFBP7 x serum creatinine / urine output; urine TIMP2 x serum creatinine; urine TIMP2 / urine output; urine TIMP2 x serum creatinine / urine output; urine IGFBP7 x serum creatinine; urine IGFBP7 / urine output; or urine IGFBP7 x serum creatinine / urine output.