WO2011090943A1

WO2011090943A1 - Removal of pathological albumin from a subject's plasma

Info

Publication number: WO2011090943A1
Application number: PCT/US2011/021550
Authority: WO
Inventors: Yukihiko Nose; Wadi N. Suki; Kazuhide Ohta; Junji Takaba; Hiroshi Miyamoto
Original assignee: Baylor College Of Medicine; Otsuka Pharmaceutical Co., Ltd.
Priority date: 2010-01-22
Filing date: 2011-01-18
Publication date: 2011-07-28
Also published as: TW201138924A

Abstract

The present invention provides methods and systems of removing pathological albumin from a subject's plasma. Such methods generally comprise: (1) the addition of an anticoagulating agent to the subject's plasma, where the anti-coagulating agent associates with the pathological albumin to form a cryo-reactive albumin; (2) separating the subject's plasma from the subject's blood to form a plasma solution; (3) cooling the plasma solution to a temperature sufficient to form cryoaggregates and cryogels that comprise cryo- reactive albumins; and (4) filtering the cooled down plasma solution through a plasma fractionation filter membrane. In various embodiments, the methods of the present invention also comprise a step of (5) warming the plasma solution to a temperature higher than about 35?C, where the warming occurs before re-infusion. In various embodiments, the methods of the present invention also comprise a hemodialysis step.

Description

TITLE

REMOVAL OF PATHOLOGICAL ALBUMIN FROM A SUBJECT'S PLASMA

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Patent Application No. 61/297,488, filed on January 22, 2010, the entirety of which is incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] This invention was not funded by any federally sponsored research grants.

BACKGROUND OF THE INVENTION

[0003] Diseases that are associated with elevated levels of pathological albumins present many health-related, financial and societal issues. For instance, one of the causes of diabetic complications is considered to be the increased level of glycated albumin (GA) in a patient's plasma. Accordingly, there is a need for the development of novel methods and systems for treating diseases associated with pathological albumins (including diabetes).

BRIEF SUMMARY OF THE INVENTION

[0004] In some embodiments, the present invention provides methods of removing pathological albumin (e.g., glycated albumin) from a subject's plasma. Such methods generally comprise: (1) the addition of an anti-coagulating agent (e.g., heparin) to the subject's plasma, where the anti- coagulating agent associates with the pathological albumin to form a cryo-reactive albumin; (2) separating the subject's plasma from the subject's blood to form a plasma solution; (3) cooling the plasma solution to a temperature sufficient to form cryoaggregates and cryogels that comprise cryo-reactive albumins (e.g., temperatures lower than about 10 °C); and (4) filtering the cooled down plasma solution through a plasma fractionation filter membrane (e.g., a plasma fractionation filter membrane with a pore size of about 0.05 μηι to about 0.2 μιη and a surface area larger than about 0.8 m²). In this step, the plasma fractionation filter membrane retains the cryogels and the cryoaggregates (containing cryo-reactive albumins) and releases the remaining plasma solution.

[0005] The methods of the present invention can also comprise a step for warming the plasma solution (desirably to a temperature higher than about 35 °C) before re-infusion to subjects. In general, the cooled plasma should be warmed prior to returning to the patient (desirably to temperatures higher than 35°C). Such warming up can be essential to safe procedures. In some embodiments, such warming occurs after the filtering step (i.e., step 4). [0006] The methods of the present invention have various additional embodiments. For instance, in some embodiments, the adding of the anti-coagulating agent (i.e., step 1) occurs by intravenous administration of the anti-coagulating agent to the subject prior to the plasma separating step (i.e., step 2). In some embodiments, the plasma separating step involves at least one of (1) filtering the subject's blood through a plasma separation filter membrane; and/or (2) the utilization of a centrifugal method in order to separate the plasma from whole blood. In various embodiments, the cooling of the plasma solution (i.e., step 3) comprises passing the plasma solution through a cooling chamber (e.g., a cooling chamber connected to a heat exchanger). In some embodiments, the warming step (i.e., a warming step after step 4) comprises passing the plasma solution through a warming chamber (step 4). Furthermore, the methods of the present invention may occur on-line or off-line.

[0007] Further embodiments of the present invention pertain to systems for removing pathological albumin from a patient's plasma in accordance with the methods of the present invention. In some embodiments, such systems are generally referred to as cryo-reactive albumin removal apheresis (CRARA) systems. In various embodiments, such systems comprise (1) a plasma separator (either membrane and/or centrifugal) for separating plasma from whole blood; (2) a cooler for cooling the plasma to a temperature sufficient to form cryogels and cryoaggregates; (3) a filter for separating the cryogels and cryoaggregates from the plasma; and (4) a warmer for warming the plasma.

[0008] As set forth in more detail below, the methods and systems of the present invention provide numerous improvements in treating various conditions and diseases in various subjects. For instance, in some embodiments, the methods and systems of the present invention may be used to treat human beings suffering from diabetes. In addition, it is envisioned that the methods and systems of the present invention can provide various improved therapies for various other diseases, including, without limitation, autoimmune diseases, renal failure, atherosclerosis, cardiomyopathy, and chronic respiratory failure.

BRIEF DESCRIPTION OF THE FIGURES

[0009] In order that the manner in which the above recited and other advantages and objects of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof, which are illustrated in the appended Figures. Understanding that these Figures depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope, the invention will be described with additional specificity and detail through the use of the accompanying Figures in which:

[0010] FIGURE 1. Provides a schematic illustration of an exemplary cryo-reactive albumin removal apheresis (CRARA) system that can be used in conjunction with the methods of the present invention to remove pathological albumin from a subject's plasma.

[0011] FIGURE 2 illustrates various aspects of cryogels and croyaggregates.

[0012] FIG. 2A illustrates the effect of reduced temperatures on plasma turbidity (i.e., temperatures at or below 30°C).

[0013] FIG. 2B illustrates various components associated with a cryogel that is formed when a plasma solution is cooled down (e.g., to temperatures lower than 4°C).

[0014] FIG. 2C illustrates particle size distribution in cooled down plasma. As indicated, particle sizes increase with lower temperatures.

[0015] FIGURE 3 illustrates various additional pathological albumin removal systems that can be utilized in accordance with various embodiments of the present invention.

[0016] FIGURE 4 shows experimental results pertaining to the in vitro removal of glycated albumin from the plasma of diabetic renal failure patients. In these experiments, the plasma samples were cooled down to temperatures near 0°C and filtered through a 0.2 μιη filter membrane.

[0017] FIGURE 5 shows the percentage decrease of various macromolecules that were removed from the plasma of non-ischemic cardiomyopathic patients by cryoaggregate filtration. The results show approximately 40% reduction in IgG3, IgM, and fibrinogen levels. The results also show approximately 37% reduction in T-cholesterol levels and approximately 20% reduction in albumin levels (Alb). [0018] FIGURE 6 illustrates a comparison of the cryoaggregation of albumin and globulin at different temperatures. The chart illustrates that the cryoaggregation of albumin is more effective at lower temperatures (i.e., temperatures between about 0°C to about 10°C). In contrast, the cryoaggregation of globulin is more effective at higher temperatures (i.e., temperatures between about 10°C to about 30°C).

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0019] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention, as claimed. In this application, the use of the singular includes the plural, the word "a" or "an" means "at least one", and the use of "or" means "and/or", unless specifically stated otherwise. Furthermore, the use of the term "including", as well as other forms, such as "includes" and "included", is not limiting. Also, terms such as "element" or "component" encompass both elements or components comprising one unit and elements or components that comprise more than one unit unless specifically stated otherwise.

[0020] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. All documents, or portions of documents, cited in this application, including, but not limited to, patents, patent applications, articles, books, and treatises, are hereby expressly incorporated herein by reference in their entirety for any purpose. In the event that one or more of the incorporated literature and similar materials defines a term in a manner that contradicts the definition of that term in this application, this application controls.

[0021] Modified forms of albumins are associated with many types of diseases (herein referred to as pathological albumins). For instance, one of the causes of diabetic complications in the kidneys, eyes, legs and circulatory systems are considered to be the increased level of glycated albumin (GA) in patients' plasma. In general, the patients develop diabetic complications when more than about 20% of patients' plasma albumin levels are converted to GA.

[0022] In fact, GA is recognized as a reliable marker for monitoring glycemic control, particularly in patients with end stage renal disease. For instance, it was demonstrated that diabetic patients with end stage renal disease that had high GA levels (> 29%) did not survive more than seven years. In contrast, 20% of patients with low GA levels (<29 %) survived longer than 10 years. See Fuk oka et al, "Glycated albumin levels predict long-term survival in diabetic patients undergoing haemodialysis." Nephrology. 2008 (13):278-283.

[0023] Furthermore, diseases associated with elevated levels of pathological albumins present many health-related, financial and societal implications. For instance, diabetic patients suffer from many diabetic complications, including damage to the eyes, kidneys, nervous system, heart and circulatory system. Unfortunately, many of these complications become the cause of death for these diabetic patients.

[0024] As an example, one of the most expensive complications for diabetic patients is kidney failure. At this time, approximately 1.5 million patients are on dialysis worldwide. More than half of these patients (particularly in Japan) have diabetes-induced kidney failures. To maintain these diabetic patients alive only on dialysis may cost at least $40 billion. In addition, many patients on dialysis develop eye and leg circulation failures that may eventually result in loss of eyesight and/or limbs.

[0025] Moreover, new cases of diabetes (especially Type 2 diabetes) are increasing at a significant rate. For instance, about 285 million suffer from diabetes worldwide. Furthermore, according to the American Diabetic Association, about 1.3 million people are diagnosed with diabetes each year in the United States. Therefore, it is estimated that there will be approximately 438 million diabetic patients in the world by 2030.

[0026] Not surprisingly, approximately 12% of all worldwide medical care costs (~$340 billion) are spent on diabetic therapy at this time. Accordingly, the above-mentioned problems present a need for the development of novel methods and systems for treating diseases associated with pathological albumin (including diabetes).

[0027] Various embodiments of the present invention provide methods of treating diseases that are associated with pathological albumin (e.g., diabetes). Such methods generally involve the removal of pathological albumin (e.g., glycated albumin) from a subject's plasma. In particular, such methods generally comprise: (1) the addition of an anti-coagulating agent (e.g., heparin) to the subject's plasma, where the anti-coagulating agent associates with the pathological albumin to form a cryo-reactive albumin; (2) separating the subject's plasma from the subject's blood to form a plasma solution; (3) cooling the plasma solution to a temperature sufficient to form cryoaggregates and cryogels that contain the cryo-reactive albumin (e.g., lower than about 10 °C); and (4) filtering the cooled down plasma solution through a plasma fractionation filter membrane (e.g., a plasma fractionation filter membrane with a pore size of about 0.05 μιη to about 0.2 μιη and a surface area larger than about 0.8 m ). The methods of the present invention can also comprise warming the plasma solution, desirably to a temperature higher than about 35 °C, prior to re-infusion into a patient.

[0028] In further embodiments, the methods of the present invention also comprise a hemodialysis of the subject's plasma. In some embodiments, the hemodialysis occurs after the aforementioned steps 1-4. The methods of the present invention may occur on-line (i.e., while a system is connected to a patient) or off-line (i.e., in-vitro or while the system is disconnected from a patient).

[0029] Further embodiments of the present invention pertain to systems for removing pathological albumin from a patient's plasma. In some embodiments, such systems are generally referred to as cryo-reactive albumin removal apheresis (CRARA) systems. In various embodiments, such systems generally comprise: (1) a plasma separator for separating plasma from whole blood; (2) a cooler for cooling the plasma to a temperature sufficient to form cryogels and cryoaggregates; (3) a filter for separating the cryogels and cryoaggregates from the plasma; and a (4) warmer for warming the plasma. In additional enbodiments, the systems of the present invention may also comprise (5) a hemodialysis system for further plasma purification.

[0030] As set forth in more detail below, the previously available apheresis systems that cooled down plasma below 30°C were aiming to remove pathological globulin groups from patients. In contrast, the systems and methods of the present invention are aiming to remove pathological albumin molecules that are cryo-reactive from a patient's plasma. In fact, prior systems attempted to keep albumin molecules in the patients' plasma.

[0031] A specific example of a CRARA system in accordance with some embodiments of the present invention is shown as CRARA system 10 in FIG. 1 This system generally comprises a plasma separator 14 with a filter 15; a cooler 18; a filter 24 with a pore size of about 0.05-0.2 μιη and a surface area of larger than 0.8 m ; a warmer 28; and an optional hemodialysis system 32. Cooler 18 and warmer 28 are optionally associated with heat exchangers 20 and 29, respectively. In addition, the various components of the system are in fluid communication with each other and with patient 11 via a tubing network (i.e., tubings 12, 16, 22, 26 and 30-31). As well known by persons of ordinary skill in the art, CRARA system 10 may also be associated with various pumps, valves and other mechanical devices to facilitate fluid flow between the different components and tubing networks.

[0032] A specific method of operating CRARA system 10 will now be described in detail as an exemplary embodiment of the claimed methods of removing pathological albumins from a subject's plasma. In this embodiment, heparin is first intravenously administered to patient 11, desirably at dose levels of about 200 units per kg of body weight of the patient. Without being bound by theory, it is envisioned that heparin associates with the pathological albumin in the patient's blood to form a cryo-reactive albumin.

[0033] After the completion of heparin administration, the patient is connected to CRARA system 10 via tubings 12 and 31. The CRARA system is then actuated, thereby resulting in the extra-corporeal pumping out of the patient's whole blood to plasma separator 14 via tubing 12.

[0034] Thereafter, plasma separator 14 utilizes filter 15 to separate the whole blood into a plasma solution containing the cryo-reactive albumin, and a non-plasma solution containing other blood components (e.g., red blood cells, platelets, and leukocytes). Next, the non-plasma solution flows back into patient 11 via tubing 31. The plasma solution containing the cryo- reactive albumin flows into cooler 18 via tubing 16.

[0035] Thereafter, cooler 18 utilizes heat exchanger 20 to cool the plasma solution to a temperature lower than about 10 °C. This results in the formation of cryoaggregates and cryogels that contain cryo-reactive albumin (typically, cryoreactive albumins form cryoaggregates at 4-10°C and cryogels at 0-4°C). Thereafter, the cooled down plasma solution flows to filter 24. The plasma fractionation filter membrane in filter 24 retains the cryogels and the cryoaggregates containing the cryo-reactive albumin. In addition, the plasma fractionation filter membrane releases the remaining plasma solution to warmer 28 through tubing 26.

[0036] Subsequently, warmer 28 utilizes heat exchanger 29 to warm the plasma solution to about 35°C -40 °C. The warmed plasma solution then flows back into patient 11 through tubings 30 and 31. Optionally, the warmed plasma solution may also flow into hemodialysis system 32 for additional treatment before flowing back into patient 11. [0037] In some embodiments, the aforementioned treatment may occur within the framework of five sessions for three hours in ten days. Other treatments regimens can also be envisioned by persons of ordinary skill in the art.

[0038] Applicants re-assert that the above-described method and system in FIG. 1 constitutes a specific embodiment of the present invention. Other embodiments of such methods and systems can be envisioned by a person of ordinary skill in the art. For instance, Applicants note that plasma separator 14 in FIG. 1 is a filtration unit with filter 15. However, in other embodiments, plasma separator 14 may be a centrifuge -based plasma separator.

[0039] Various other embodiments of the methods and systems of the present invention will now be discussed with more elaboration below as non-limiting examples.

[0040] Association of Pathological Albumins with Anti-coagulating Agents

[0041] As used herein, pathological albumins refer to modified forms of albumin that are associated with one or more diseases. In some embodiments, the pathological albumin is a glycated albumin (GA). In some embodiments, GA is associated with various types of diabetes. In fact, GA is a very reactive albumin. Together with heparin, it forms a conjugated glycated albumin when the blood is cooled down below 30°C. Other forms of pathological albumins can also be envisioned by persons of ordinary skill in the art.

[0042] A person of ordinary skill in the art will also recognize that various methods exist for the removal of pathological albumins from the subject's plasma. Such methods generally involve the association of the pathological albumin with one or more anti-coagulating agents. Without being bound by theory, it is envisioned that many pathological albumins become more cryo- reactive when they become associated with anti-coagulating agents. As described in more detail below, the formed cryo-reactive albumins can then be removed from the plasma by cooling the plasma.

[0043] A person of ordinary skill in the art will also recognize that various anti-coagulating agents may be used to associate with pathological albumins to form cryo-reactive albumins. In some embodiments, the anti-coagulating agent is heparin. In other embodiments, the anti- coagulating agent may be a heparin-like molecule, such as a heparin derivative (e.g., low molecular weight heparin). In other embodiments, the anti-coagulating agent may be Coumadin, acenocoumarol, phenprocoumon, and/or phenindione.

[0044] There are also various methods of associating pathological albumins in a subject's plasma with one or more anti-coagulating agents to form cryo-reactive albumins. In some embodiments, the association occurs by intravenously administering an effective amount of an anti-coagulating agent, such a heparin, to a subject's whole blood. In the case of heparin, effective amounts of anti-coagulant administration can include about 100 units to about 200 units per kg of the subject's body weight.

[0045] Other methods of associating pathological albumins in a subject's plasma with one or more anti-coagulating agents can also be envisioned by persons of ordinary skill in the art. For instance, in some embodiments, the anti-coagulant may be associated with the pathological albumin after a subject's whole blood is extracted from the subject. In other embodiments, the association may occur after the plasma is separated from the whole blood.

[0046] Plasma Separation Methods

[0047] As used herein, plasma separation refers to one or more methods of separating a subject's plasma from other components in the subject's whole blood (e.g., red blood cells, leukocytes and platelets). Various methods may be used to accomplish this task, as known by persons of ordinary skill in the art. For instance, in some embodiments, plasma separation occurs by centrifugation of the whole blood, in accordance with methods well known in the art.

[0048] In more preferred embodiments, plasma separation occurs by the filtration of the whole blood. In such embodiments, various filtration membranes can be used for the plasma separation step. In particular, filters of the present invention may be any type common in the art. In various embodiments, the filters are comprised of a microfiber medium.

[0049] Various materials can also be used for forming the filters. In various embodiments, the materials include polyester, polypropylene, polyamide, polyethylene and the like. In some embodiments, the materials are preferably hydrophobic polypropylene and polyesters (e.g., polyethylene terephthalate). [0050] The filters used to separate plasma from whole blood can also have various pore sizes. For instance, in some embodiments, the plasma separation filter membranes may have a pore size that ranges from about 0.1 μιη to about 0.5 μιη. Other suitable filter pore sizes can also be envisioned by persons of ordinary skill in the art.

[0051] A person of ordinary skill in the art will also recognize that the plasma separation step can occur in various structures and devices. For instance, as shown in FIG. 1 and described above, plasma separation in some embodiments can occur in a plasma separator 14 that comprises a filter 15 for separating the plasma solution from the whole blood and transporting it to a cooler.

[0052] Plasma Cooling Methods

[0053] In general, it desirable to cool the separated plasma solution to a temperature that is suitable for forming cryoaggregates and cryogels. The terms cryoaggregates and cryogels are well-known to persons of ordinary skill in the art. The terms are also discussed in more detail in U.S. Pat. No. 12/864,290.

[0054] In general, when a plasma solution is cooled below about 30°C, the plasma forms cryoaggregates. As illustrated in FIG. 2A, such cryoaggregates are generally characterized by turning a clear yellowish colored plasma to a white and milky solution. Furthermore, when the plasma is cooled below about 4°C, the plasma forms cryogels. Exemplary components of cryogels are illustrated in FIG. 2B. As shown in FIG. 2C, the molecular sizes of the aggregated molecules in the plasma become larger as the temperature decreases during cryoaggregation and cryogel formation.

[0055] However, Applicants notes that suitable temperatures for the formation of cryogels and cryoaggregates can vary depending on environmental conditions, such as pressure. Generally, such temperatures are less than about 10 °C. In more specific embodiments, such temperatures may range from about 10 °C to about 0 °C. In more specific embodiments, the temperature is about 4 °C. [0056] In some embodiments, the cooling down of the plasma to a temperature lower than about 10°C in the presence of the formed cryo-reactive albumins results in their association with the formed cryoaggregates and cryogels. Accordingly, the removal of both the cryoaggregates and the cryogels at such temperatures can effectively eliminate substantial amounts of cryoreactive albumins from a subject's plasma.

[0057] A person of ordinary skill in the art will also recognize that various methods exist for cooling a plasma solution. In some embodiments, the cooling may occur by passing the plasma solution through a cooling chamber, such as cooler 18 shown in FIG. 1. In further embodiments, the cooling chamber may be associated with a heat exchanger, such as heat exchanger 20 shown in FIG. 1. In additional embodiments, the heat exchanger may be an electrical device that associates the cooling chamber with a cooling fluid, such as liquid nitrogen, water, or other fluids. In further embodiments, the cooling chamber may be associated with ice, dry ice, liquid nitrogen, water, or other cooling fluids in the presence or absence of a heat exchanger.

[0058] Plasma Filtration Methods

[0059] In general, the plasma filtration methods of the present invention aim to separate the cooled plasma from the formed cryoaggregates and cryogels in the plasma solution. This in turn removes the pathological albumins that are associated with the cryogels and the cryoaggregates from the plasma solution. A person of ordinary skill in the art will also recognize that various plasma filtration methods exist.

[0060] In general, the plasma filtration methods of the present invention utilize plasma fractionation filter membranes that have pore sizes sufficient to retain cryogels and cryoaggregates that were derived from cooled down plasma solutions. Suitable plasma fractionation filter membranes have been described above. In some embodiments, the plasma fractionation filter membrane has a pore size that ranges from about 0.01 μιη to about 0.5 μιη. In more preferred embodiments, the plasma fractionation filter membrane has a pore size that ranges from about 0.05 μιη to about 0.2 μιη. In another preferred embodiment, the membrane has a pore size of about 0.2 μιη. Other suitable plasma fractionation filter membrane pore sizes can also be envisioned by persons of ordinary skill in the art. [0061] Furthermore, the filters can have various surfaces areas. In a preferred embodiment, the filter has a surface area larger than about 0.8 m . In more preferred embodiments, the filter has a surface area larger than about 0.8 m and a pore size of about 0.2 μιη.

[0062] As set forth in more detail below, the filtered plasma solution can be returned to a subject directly after warming or after further treatment (e.g., hemodialysis).

[0063] Plasma Warming Methods

[0064] In general, it desirable to warm the plasma solution after filtration to a temperature that is suitable for re-entry to the subject's circulatory system. Generally, such temperatures are more than about 30 °C. In more preferred embodiments, such temperatures may range from about 35 °C to about 40 °C.

[0065] A person of ordinary skill in the art will also recognize that various methods exist for warming the plasma solution. In some embodiments, the warming may occur by passing the plasma solution through a warming chamber, such as warmer 28 shown in FIG. 1. In further embodiments, the warming chamber may be associated with a heat exchanger, such as heat exchanger 29 shown in FIG. 1. In additional embodiments, the heat exchanger may be an electrical device that associates the warming chamber with a warming fluid, such as water or other fluids. In further embodiments, the warming chamber may be associated with water or other warming fluids without association with a heat exchanger.

[0066] Applicants also note that many embodiments of the present invention may not utilize a plasma warming method. For instance, in some embodiments, the plasma temperature may be warmed to a suitable temperature by simple incubation at room temperature for a desired amount of time.

[0067] Hemodialysis Methods

[0068] As used herein, hemodialysis methods generally refer to dialysis methods for removing waste products from a patient's circulatory system, as known by persons of ordinary skill in the art. Various embodiments of the present invention may utilize hemodialysis methods. Accordingly, many systems of the present invention may be coupled to a hemodialysis system, such as in cases where a patient is already suffering from kidney failure.

[0069] Suitable hemodialysis systems that can be used with the methods and systems of the present invention, include, without limitation, hemodialysis systems manufactured by Braun (e.g., Braun Dialog+® Hemodialysis System); and hemodialysis systems manufactured by Renal Solutions, Inc. (e.g., The Allient® Sorbent Hemodialysis System). Other suitable hemodialysis systems can also be envisioned by persons of ordinary skill in the art.

[0070] In various embodiments, the hemodialysis may occur before, during or after the removal of pathological albumin from a plasma solution. For instance, in some embodiments, the hemodialysis occurs after the cooled down plasma solution is filtered and warmed, as described previously. In other embodiments, the hemodialysis may occur after the cooled down plasma solution is filtered, but before it is warmed.

[0071] In some embodiments, hemodialysis procedures necessitate providing heparin and also exteriorizing blood outside of the body, which might cool the blood down below 35°C. Under such conditions, cryoaggregation of the plasma would be able to occur accidentally (along with the heparinized cryoreactive albumins). Furthermore, occlusion of the small diameter arteriole in the patient should be able to cause loss of eye sight or legs of these dialysis patients. Thus, under such circumstances, it may be desirable to remove the cryo-reactive albumin in accordance with the methods of the present invention before initiating the hemodialysis.

[0072] In some embodiments, Applicants envision that the combination of CRARA therapy and hemodialysis online should be able to avoid many diabetic complications and provide therapeutic effects for patients. Desirably, CRARA therapy should occur before the end stage of kidney failure that would necessitate hemodialysis.

[0073] Pathological Albumin Removal Systems

[0074] Further embodiments of the present invention pertain to systems for removing pathological albumin from a patient's plasma. In some embodiments, such systems are generally referred to as cryo-reactive albumin removal apheresis (CRARA) systems. In further embodiments, such systems may also be referred to as pressure and temperature controlled apheresis therapy (PAT CAT) systems. Such systems may also be off-line automatic plasma purifier for exchange transfusion (Off-LAPPET) systems.

[0075] Regardless of designation, the systems of the present invention in various embodiments generally comprise: (1) a plasma separator for separating plasma from whole blood; (2) a cooler for cooling the plasma to a temperature sufficient to form cryogels and cryoaggregates; (3) a filter for separating the cryogels and cryoaggregates from the plasma; and a (4) warmer for warming the plasma. In additional embodiments the systems of the present invention may further comprise a (5) hemodialysis system.

[0076] The systems of the present invention may also be associated with various components for controlling fluid flow, pressure, and temperature. For instance, in some embodiments, it may be essential to utilize pressure controllers to maintain the transmembrane pressure of the plasma separator systems near 0 mmHg or below about 50 mmHg. Such low pressure ranges may be required to maintain effective plasma separation in some embodiments. On the other hand, the transmembrane pressures of the plasma fractionator maintains the transmembrane pressure below 300 mmHg.

[0077] In various embodiments, blood pumps may be used to properly control the extracorporeal blood flow. Typically, such extracorporeal blood flow rates are maintained at less than about 100 ml/min. However, other extracorporeal blood flow rates can also be achieved in other embodiments.

[0078] Equipment available for use in various embodiments of the present invention can be widely varied. Specific examples mentioned herein are not to be construed as limiting, as would be understood by one of ordinary skill in the art. For example, in general, any blood pump can be used. Examples of blood pumps include roller pump, systolic pumps, a reciprocating pump, double-action pump, suction pump, piston pump, kinetic pump, and/or the like. In various embodiments, blood may be removed from a patient at a rate of up to 100 ml/min. However, any rate acceptable in the art field can be used with various embodiments of the present invention.

[0079] A suitable CRARA system for removing pathological albumins is shown in FIG. 1. The components of this CRARA system were previously described in detail. Other suitable pathological albumin removal systems can also be envisioned by persons of ordinary skill in the art.

[0080] For instance, another embodiment of a proposed pathological albumin removal system is illustrated in FIG. 3A. As shown, pathological albumin removal system 150 comprises a patient 100 (not shown) or other source of fluid containing plasma, a heparin infusion pump 110, a first blood pump 120, a plasma filter 130, a second blood pump (for separated plasma) 140, a third blood pump 155, a harvested plasma bag 145 or storage container, and a purified plasma bag 160 or storage container. In various embodiments, the aforementioned components are connected via tubing or pipes, such as tube 103, tube 195, tube 190, and tube 180. Multiple pressure and/or temperature readings are capable of being taken at various locations along the tubes. In an embodiment, there is a pressure instrument at site 122, a second pressure instrument at site 124, a third pressure instrument at site 165, and a fourth pressure instrument at site 167.

[0081] In an embodiment, a first blood pump 120 withdraws blood from patient 100 (not shown) through tube 103. Pressure instrument 122 may be coupled to first blood pump 120 such that the rate of first blood pump 120 can be controlled by the pressure in tube 103 and/or pressure in tube 195. If needed, heparin can be infused to the withdrawn blood from heparin pump 110. The withdrawn blood is then conveyed along tube 195 across pressure instrument 124 and into plasma separator 130 where plasma is filtered from the other components of the subject's blood.

[0082] In various embodiments, the pressure entering plasma filter 130 is such that it will not clog the filter. As previously described for the plasma filter (130), it is important in some embodiments to keep the transmembrane pressure of the plasma fractionation filter membrane at a suitable pressure. As such, P2 and P3 pressure instruments are utilized in some embodiments to maintain the transmembrane pressure of the filter membrane. For instance, in some embodiments, the transmembrane pressure of the plasma fractionation filter membrane should not exceed 300 mmHg.

[0083] The separated plasma solution is then conveyed along tube 190 to a harvested plasma bag 145. A second blood pump 140 can also be used to pump the plasma solution into a harvested plasma bag 145, if needed or desired. Harvested plasma bag 145 is then taken off-line for further processing, such as for plasma cooling to form cryogels and cryoaggregates followed by filtration, as previously described.

[0084] For instance, in some embodiments, the harvested plasma bag 145 from FIG. 3A is removed from system 150 and connected to system 200 shown in FIG. 3B as plasma bag 220. Cryoaggregate pump 260 pumps the plasma solution across a cooling unit 250 where the temperature of the plasma solution is reduced to below 10°C to commence the formation of cryoaggregates and cryogels. The cooled plasma solution is then fed to at least one filter 240 wherein the cryoaggregates and cryogels are separated. The tubing network then conveys the purified plasma solution from filter 240 to the purified plasma bag 210.

[0085] The processed plasma may then be re-connected into system 150 shown in FIG. 3A as purified plasma bag 160 and re-infused to patient 100. In particular, the purified plasma stream is pumped from purified plasma bag 160 by the third blood pump 155 back to patient 100, where it can be re-infused.

[0086] Applicants note that FIG. 3 illustrates an off line CRARA method and system. In particular, in this embodiment, the patient's plasma (containing cryo-reactive albumin) is placed in plasma bag 145 and processed in vitro. The purified plasma is then re-infused into the patient.

[0087] However, Applicants also note that the CRARA system in FIG. 3 can be established as an on-line system by combining the systems shown in FIGS. 3A and 3B. Another on-line CRARA system was previously shown in FIG. 1 and described in detail. In various embodiments, such on-line systems provide a simpler system for removal of pathological albumin from a patient's plasma. Nonetheless, since many apheresis centers utilize centrifugation to separate plasma, off-line CRARA systems are also applicable systems.

[0088] Applications

[0089] From the detailed description above, a person of ordinary skill in the art will recognize that the methods and systems of the present invention provide numerous improvements in treating various conditions and diseases in various subjects. For instance, in some embodiments, the methods and systems of the present invention may be used to treat human beings suffering from various types of diabetes (e.g., Type 1 diabetes, Type 2 diabetes, diabetes mellitus, juvenile diabetes, and gestational diabetes).

[0090] In addition, it is envisioned that the methods and systems of the present invention can provide various improved therapies for various other diseases that may be associated with complication from diabetes. Examples of such diseases include, without limitation, autoimmune diseases, renal failure, atherosclerosis, cardiomyopathy, and chronic respiratory failure.

[0091] In fact, Applicants envision that effective removal of pathological albumin from diabetic patients' plasma should be able to reduce or eliminate microvascular complications that occur in end stage diabetic patients. Such complications may include diabetic nephropathy. The complications may also include diabetic retinopathy and neuropathy that lead to circulatory failure in patients.

[0092] Other applications of the methods and systems of the present invention include possible removal of pathological albumin for the prevention of auto-immune diseases, such as rheumatoid arthritis. By way of background, when rheumatoid arthritis patients were subjected to cryogel filtration (cryofiltration), approximately 20% of albumin was removed at the first session of therapy. However, for the second and the third sessions, there was no removal of albumin (unpublished data). Thus, with cryofiltration, administration of albumin was not necessary, because albumin was not removed after the second therapy. This albumin in existence for rheumatoid arthritis patients was not glycated albumin (GA), as increased in diabetic patients. Nonetheless, for the treatment of rheumatoid arthritis patients, it is essential to remove not only pathological globulin, but also pathological albumin.

[0093] It would also be anticipated that the methods and systems of the present disclosure can be utilized to treat various vascular complications associated with diabetic diseases, including kidney failures. In some embodiments, Applicants envision that CRARA therapy of less than 5 sessions should be able to keep the diabetic patient complication free for longer than four years when blood sugar is controlled properly..

[0094] Additional Embodiments

[0095] From the above invention, a person of ordinary skill in the art will recognize that the methods and systems of the present invention can have numerous additional embodiments. Reference will now be made to more specific embodiments of the present invention and experimental results that provide support for such embodiments. However, Applicants note that the invention below is for exemplary purposes only and is not intended to limit the scope of the claimed invention in any way.

[0096] EXAMPLES

Additional details about the experimental aspects of the above-described studies are discussed in the subsections below.

[0097] Example 1: In vitro GA removal from the plasma of diabetic renal failure patients.

[0098] Heparinized plasma samples from 16 diabetic renal failure patients and 5 non-diabetic patients were collected and cooled down to about 4 °C. The collected plasma samples were then filtered in vitro through a 0.2 μιη filter. The GA levels of the treated plasma were then analyzed. The results are shown in FIG. 4.

[0099] The results show that cryo-reactive glycated albumin was effectively removed by the above-described heparinization and cooling process. In other embodiments, Applicants also envision that effective GA removal can be established when the plasma is cooled down to temperatures of about 5+5 °C. Applicants also envision effective GA removal when CRARA filters with 0.05-0.2 μιη pore sizes are used .

[00100] Example 2. Cryoaggregate filtration of the plasma of non-ischemic cardiomyopathic patients

[00101] The aim of this trial was to remove pathological macromolecules from cardiomyopathic patients by cryoaggregate filtration. This method aimed primarily to remove pathological globulin, not albumin. Plasma samples from four patients with non-ischemic cardiomyopathy were collected and cooled down to about 10-15 °C. The collected plasma was then filtered in vitro through a 0.02-0.03 μιη filter. The levels of various macromolecules were then analyzed. The results are shown in FIG. 5.

[00102] In particular, the results show approximately 40% reduction in IgG3, IgM, and fibrinogen levels. The results also show approximately 37% reduction in T-cholesterol levels. However, the results only show approximately 20% reduction in albumin levels (Alb). Without being bound by theory, Applicants envision that such a low albumin removal rates in these samples was because the albumin in the samples did not constitute pathological albumin, as defined in the present invention (e.g., glycated albumin). Thus, this experiment demonstrates that the methods and systems of the present invention are more effective in removing pathological albumins (i.e., glycated albumins) than non-pathological albumins (at least in some embodiments).

[00103] Summary

[00104] By way of background, approximately 30 years ago, double filtration plasmapheresis was introduced. This apheresis method removed any molecules in the plasma that were larger than albumin. At around the same time, cryofiltration (one type of double filtration plasmapheresis) was introduced by Malchesky, P. and Nose, Y. This technology was patented and used for the treatment of auto-immune diseases, particularly malignant rheumatoid arthritis.

[00105] During the same time period, thermofiltration and other methods of removing pathological molecules (including cryoaggregate filtration) were introduced. For instance, thermofiltration was effectively used for hyperlipedmia patients. Likewise, cryoaggregate filtration was used for cardiomyopathic patients (both non-ischemic and ischemic). However, during that time period, no one recognized the existence of pathological albumins, particularly in diabetic patients. Furthermore, no one was aware of the therapeutic effects of removing such pathological albumins, especially in diabetic patients.

[00106] Rather, prior double filtration systems and methods were attempting to keep albumin molecules in the patients and instead remove pathological globulins. Most of the prior methods and systems accomplished this task by cooling down plasma samples to temperatures between about 10°C-30°C.

[00107] As described above, molecular sizes of cryoaggregates become larger when the cooled down temperatures are lowered. See FIG. 2C. Since the size of albumin is smaller compared with that of globulin, the lower temperatures (5+5 °C) for the removal of cryoreactive albumins are necessary compared with the removal of cryoreactive globulins (20+10 °C). See FIG. 6. Thus, the conditions utilized in the prior systems would not have been able to remove pathological albumins that become cryo-reactive. Table 1 below provides a comparison of the old procedures with the new procedures described above.

Table 1. Differences between old and new plasma treatment procedures. The old procedures are indicated with an asterix (*)

[00108] In further contrast to the prior systems, the methods and systems of the present invention remove not only cryoaggregates formed at lower temperatures, but also cryogels. Furthermore, the above-described systems and methods of the present invention aim to remove pathological albumin molecules that are cryo-reactive and exist in a patient's plasma. In some embodiments, the systems of the present invention remove such pathological albumins from the plasma of diabetic patients.

[00109] Without further elaboration, it is believed that one skilled in the art can, using the description herein, utilize the present invention to its fullest extent. The embodiments described herein are to be construed as illustrative and not as constraining the remainder of the invention in any way whatsoever. While the preferred embodiments have been shown and described, many variations and modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the invention. Accordingly, the scope of protection is not limited by the description set out above, but is only limited by the claims, including all equivalents of the subject matter of the claims. The inventions of all patents, patent applications and publications cited herein are hereby incorporated herein by reference, to the extent that they provide procedural or other details consistent with and supplementary to those set forth herein.

Claims

CLAIMS What is claimed is:

1. A method of removing pathological albumin from a subject's plasma, wherein the method comprises: adding an anti-coagulating agent to the subject's plasma, wherein the anti-coagulating agent associates with the pathological albumin to form a cryo-reactive albumin; separating the subject's plasma from the subject's blood to form a plasma solution; cooling the plasma solution to a temperature sufficient to form cryoaggregates and cryogels, wherein the formed cryoaggregates and cryogels comprise cryo-reactive albumin; and filtering the cooled down plasma solution through a plasma fractionation filter membrane, wherein the plasma fractionation filter membrane retains the cryogels and the cryoaggregates and releases the remaining plasma solution.

2. The method of claim 1, wherein the pathological albumin comprises glycated albumin.

3. The method of claim 1, wherein the anti-coagulating agent is heparin.

4. The method of claim 1, wherein the adding of the anti-coagulating agent occurs by intravenous administration of the anti-coagulating agent to the subject prior to the separating step.

5. The method of claim 4, wherein the anti-coagulating agent is heparin, and wherein heparin is intravenously administered to the subject at a dose higher than about 100 units/kg of the subject's body weight.

6. The method of claim 1, wherein the separating comprises filtering the subject's blood through a filter membrane.

7. The method of claim 1, wherein the separating comprises a centrifugation of the subject's blood.

8. The method of claim 1, wherein the cooling of the plasma solution comprises cooling the plasma solution to a temperature lower than about 10 °C.

9. The method of claim 1, wherein the cooling of the plasma solution comprises passing the plasma solution through a cooling chamber.

10. The method of claim 1, wherein the plasma fractionation filter membrane has a pore size of about 0.05 μιη to about 0.2 μιη.

11. The method of claim 1, wherein the plasma fractionation filter membrane has a surface area larger than about 0.8 m .

12. The method of claim 1, further comprising warming the plasma solution to a temperature higher than about 35 °C, wherein the warming occurs before re-infusion of the plasma solution.

13. The method of claim 1, further comprising a hemodialysis of the subject's plasma.

14. The method of claim 1, wherein the subject is a human being suffering from diabetes.

15. The method of claim 1, wherein the method is off-line.

16. The method of claim 1, wherein the method is on-line.

17. A system for removing pathological albumin from a patient's plasma, wherein the system comprises: a plasma separator for separating plasma from whole blood; a cooler for cooling the plasma to a temperature sufficient to form cryogels and cryoaggregates; and a filter for separating the cryogels and cryoaggregates from the plasma.

18. The system of claim 17, further comprising a warmer for warming the plasma.

19. The system of claim 17, further comprising a hemodialysis system.

20. The system of claim 17, wherein the filter has a pore size of about 0.05 μιη to about 0.2 μιη.

21. The system of claim 17, wherein the filter has a surface area larger than about 0.8 m .