Method and apparatus for removing viral contaminants from a body fluid

A method for treating a body fluid to at least substantially inactivate viral contaminants that may be present therein is provided. The method includes the steps of: providing a body fluid; adding to the body fluid a viral inactivating agent to create a resultant product; and passing the resultant product through a column including material having an affinity for the viral inactivating agent.

BACKGROUND OF THE INVENTION
 The present invention relates generally to the collection and therapeutic
 use of body fluids. More specifically, the present invention relates to
 methods and devices for attempting to substantially reduce or eliminate
 potential viral contaminants and other pathogens in body fluids, such as
 blood.
 Of course, in a wide variety of therapies, such as transfusions and
 transplants, body fluids, especially blood components, such as red blood
 cells, platelets, plasma, and bone marrow, are infused from one or more
 individuals into a patient. Although such therapies provide treatments,
 many of which are life saving, and cannot otherwise be provided, due to
 the transmission of infectious diseases, there may be potential risks to
 such therapies.
 For example, it is known that blood can carry infectious agents, such as
 hepatitis virus, human immune deficiency virus (an etiological agent for
 AIDS), cytomegalovirus, Epstein Barr virus, and herpes virus. Although
 screening methods exist to identify blood that may include such viruses,
 current screening methods do not assure that every blood unit that
 contains such a virus is identified.
 For example, in this regard, one of the difficulties in testing blood
 components for viral contamination, such as HIV, is that many current
 diagnostic tests are based on an identification of antibodies. Therefore,
 a contaminated blood component will only exhibit a positive test if it
 includes antibodies for the virus, e.g., anti-HIV. With respect to
 intracellular viral infections, an individual may not generate antibodies
 immediately upon infection. Rather, there is a window period that extends
 from the initial infection of the patient with a virus to the generation
 of antibodies. When an individual is in this window period, diagnostic
 tests that are based on antibodies will not identify the individual, or
 the blood unit, as being infected. But, even though the antibodies are not
 present, the blood unit can still transmit an infection.
 With respect to HIV infection, it is believed that this window period can
 extend from approximately six weeks up to 48 months. During this time
 period, an individual who has been infected with HIV and accordingly,
 whose blood will transmit same, will register a negative antibody
 response. Currently used screening methods will not identify as
 contaminated a blood unit from an individual who is infected with HIV, but
 who has not generated anti-HIV.
 In order to address the limitations of current diagnostic techniques and
 also to deal with the concern of transmission of viral contaminants and
 other pathogens to a patient receiving a transfusion, recent attention has
 focussed on the development of viral inactivating agents. It is envisioned
 that these viral inactivation agents would be added to the body fluid
 prior to the body fluid being administered to the patient.
 For example, a number of photoactive agents that have antiviral action have
 been explored. These photoactive agents are generally agents that upon
 activation with light will inactivate or destroy pathogens, e.g., a virus
 that may be present. Such photoactive agents include: psoralens;
 porphyrins; phthalocyanines; and dyes, such as methylene blue. See, for
 example, U.S. Pat. Nos.: 4,748,120; 4,878,891; 5,120,649; and German
 Patent Application No. DE 39 30 510 A1 (Mohr).
 Although such agents provide promise for the treatment of body fluids to
 eliminate the concern of viral contamination, there may be regulatory, as
 well as possible other concerns with respect to such agents. Of course,
 the resultant body fluid to which the anti-viral agent is added will be
 infused into a patient. Therefore, it is imperative that the agent does
 not create toxicity issues or other in vivo concerns.
 With respect to photoactive agents, a still further issue is that upon
 activation of the agent and interaction of the agent with a virus, other
 products may be generated. For example, methylene blue is a photoactive
 agent that has been shown to have efficacy in inactivating viral
 contamination in plasma. Although methylene blue has been, through
 exhaustive testing, shown to have no toxicity concerns, upon
 photoactivation of methylene blue, photoproducts are generated.
 Specifically, Azure A and B are generated upon photoactivation of
 methylene blue. The in vivo effect of these products has not been as well
 studied as methylene blue in patients and therefore they raise regulatory
 issues and in vivo concerns.
 There therefore is a need for an improved method and system for treating a
 body fluid to substantially reduce, if not eliminate, viral contaminants
 that may be present therein.
 SUMMARY OF THE INVENTION
 The present invention provides a method of treating a body fluid to
 substantially inactivate viral contaminants that may be present therein.
 Pursuant to the method, to a body fluid is added a viral inactivation
 agent. The resultant product is then passed through a container, e.g.,
 column including a material having an affinity for the viral inactivating
 agent. This allows the column to remove excess viral inactivating agent.
 Additionally, other products, e.g. photoproducts, that may be generated
 upon addition of the viral inactivation agent or any activation thereof
 are also eliminated. The body fluid can then be infused into a patient
 without regulatory or toxicity concerns.
 To this end, in an embodiment, the present invention provides a method for
 treating a body fluid to at least substantially inactivate viral
 contaminants that may be present comprising the steps of: providing a body
 fluid; adding to the body fluid a viral inactivating agent to create a
 resultant product; and passing the resultant product through a column
 including material having an affinity for the viral inactivating agent.
 In an embodiment, the material includes charcoal.
 In an embodiment, the column is an ion exchange column.
 In an embodiment, the material includes neural macroporous polymeric beads
 with a high surface area for absorbing organics from aqueous solutions.
 In an embodiment, the viral inactivating agent is a light activated agent.
 In an embodiment, the viral inactivating agent is chosen from the group
 consisting of: porphyrins; psoralens; phthalocyanines; and dyes.
 The present invention also provides a method for treating a blood product
 comprising the steps of: providing a blood product; adding to the blood
 product a light activated viral inactivating agent to create a resultant
 product; irradiating the resultant product with light of a sufficient
 wavelength to activate the viral inactivating agent to create a further
 product; passing the further product through a column having an affinity
 for the viral inactivating agent; and collecting a product that passes
 through the column.
 In an embodiment, the blood product includes platelets and the viral
 inactivating agent is a psoralen.
 In an embodiment, the blood product includes plasma and the viral
 inactivating agent includes methylene blue.
 In an embodiment, the column also has an affinity for photoproducts
 generated by irradiating the resultant product.
 The present invention also provides a method for providing a blood product
 to a patient comprising the steps of: collecting a blood product from a
 donor; adding to the blood product a light activated viral inactivation
 agent; irradiating the blood product and light activated viral
 inactivation agent with light of a sufficient wavelength to activate the
 viral inactivation agent to create a resultant product; passing the
 resultant product through a column having an affinity for the viral
 inactivation agent; collecting a resultant blood product that passes
 through the column; and administering the resultant blood product to a
 patient.
 An advantage of the present invention is that it provides an improved
 method for treating a body fluid to at least substantially inactivate
 viral contaminants that may be therein.
 Another advantage of the present invention is that it provides a method for
 inactivating or eliminating pathogens from blood or its components before
 they are infused into a patient.
 Furthermore, an advantage of the present invention is that it provides a
 system that allows viral inactivating agents to be added to a body fluid
 before the fluid is infused into a patient and eliminate toxicity or
 regulatory concerns.
 Still further, an advantage of the present invention is that it provides a
 method for eliminating photoproducts from a system that adds a photoactive
 agent to a body fluid.
 Moreover, an advantage of the present invention is that it prevents any
 post thaw photoactivation of excess photoactivated agents.
 Another advantage of the present invention is that it allows normal plasma
 color for treated plasma.
 Additional features and advantages of the present invention are described
 in, and will be apparent from, the detailed description of the presently
 preferred embodiments and from the drawings.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
 The present invention provides a method and apparatus for use in treating a
 body fluid, such as blood, to reduce or eliminate viral contaminations
 that may be present therein. It is believed that the present invention can
 be used with a variety of viral inactivating agents. Such agents include,
 without limitation, photoinactivation agents, such as psoralens,
 porphyrins, dyes, such as methylene blue, phthalocyanines, phenothiazines,
 hypericin, and other compounds that are activated by light.
 As has been suggested in the art, a photoactive viral inactivating agent
 would be added to a body fluid, such as blood prior to the blood being
 infused into a patient. The resultant blood product including the
 photoactive agent then would be activated by light of a suitable
 wavelength. Of course, if desired, other viral inactivating agents that
 are not based on activation through light can be utilized in the present
 invention.
 Pursuant to the present invention, as illustrated in FIG. 1, a container 10
 will be provided including, for example, a blood component 11. The blood
 component have added thereto a viral inactivation agent 13.
 For example, it is known to collect whole blood in a blood pack. Typically,
 whole blood is then separated into its component parts. After the blood is
 separated into the respective components, using a system such as the
 Optipress.RTM. system marketed by affiliates of Baxter International, the
 blood component can be added to the container 10 including the viral
 inactivation agent. For example, methylene blue can be added to the plasma
 component. Of course, if desired, whole blood can be treated with a viral
 inactivation process. Likewise, if desired, a separate container is not
 required and the viral inactivation agent can be added to the container in
 which the component is stored.
 The container 10 will include a fluid line 12 that will be coupled to a
 column 14. As used herein, column refers broadly to a chamber or device
 that includes material that will remove specific compounds or entities.
 Accordingly, column includes cartridges, containers, and other means for
 housing such material.
 Pursuant to the present invention, the column 14 will include materials
 having an affinity for the viral inactivation agent and photoproducts
 generated thereby. The column will include an inlet 16 allowing product to
 flow into an interior 18 defined by the housing 20. In an embodiment,
 porous plates (not illustrated) are located at each end 26 and 28,
 respectively, of the interior 18 of the housing 20. The porous plates
 allow the body fluid to flow through an affinity matrix located therein.
 The resultant product then flows out of the cartridge 14 through the
 outlet 34.
 In use, after the container containing the blood product and viral
 inactivation agent is activated by light of an appropriate wavelength, the
 resultant product flows through fluid line 12 and into the affinity column
 14. The affinity column 14 will remove excess viral inactivation agents,
 as well as photoproducts. For example, with respect to methylene blue,
 excess methylene blue will be removed, as well as Azure A and B. The
 resultant blood product will then flow through fluid line 36 to a
 container 38. The blood can be stored in the container 38 and then infused
 into a patient.
 To allow selective flow through the fluid line 12, breakable cannulas, as
 are known in the art, can be provided. Of course, other means for allowing
 selective flow through the fluid line 12 can be provided.
 It should be noted that although in the illustrated embodiment the
 cartridge 14 is a separate and distinct component from the container 10, a
 unitary structure can be provided. In this regard, the column can be
 integral with the container or coupled thereto as an outlet port of the
 container.
 The material used for the matrix in the affinity column 14 can comprise a
 variety of different materials. For example, charcoal, an ion exchange
 resin, or biobeads can be used. As used herein, the term "biobeads" refers
 to neural macroporous polymeric beads with a high surface area for
 adsorbing organics from aqueous solutions. Biobeads can vary in their
 hydrophilic and hydrophobic polarities. The range of believed useful
 properties of biobeads for the present invention is as follows: polarity
 (non-polar to intermediate polarity); Dipole Moment (0.1 to 3.0); bead
 size (30 to 2000 .mu.m); average pore diameter (45 to 300 angstroms); bead
 surface area (150 to 1,600 sq. meters/gram dry bead). It has been found
 that biobeads available from Biorad Laboratories, 2000 Alfred Nobel Drive,
 Hercules, CA 94547 under the name Macro-Prep.RTM. t-butyl HIC function
 satisfactorily to remove methylene blue and methylene blue photoproducts
 Azure A and B.
 By way of example, and not limitation, examples of the present invention
 will now be given:
 EXAMPLE NO. 1
 Removal studies were performed on 4'-aminomethyl-4,5', 8-trimethyl psoralen
 (AMT). Specifically, three studies were performed, two using activated
 charcoal columns and one using an ion exchange column. The charcoal
 columns each consisted of 5.3 grams of activated charcoal obtained from a
 commercial water purification device. The ion exchange column consisted of
 less than 8.2 grams of Biorad AG 50W-X8 cation exchange resin.
 One unit (80 mL) of plasmalyte platelets containing 40 ug/mL of AMT was
 passed through the first charcoal filter at a rate of about 30 mL/min.
 This column removed 86% of the AMT as measured by HPLC. Platelet loss
 going through the column was 6%. Total protein was reduced by 33%. The
 platelet morphology score dropped from 355 to 315.
 A second charcoal column was tested at a flow rate of about 5 mL/min. This
 column removed "100% " of the AMT as measured by HPLC. Platelet loss was
 14%. Total protein increased by 14%. The platelet morphology score was
 unchanged by the column (200).
 It is clear from these data that the activated charcoal can remove
 significant amounts of the AMT drug. The removal is inversely proportional
 to flow rate. The charcoal also appears to remove about one third of the
 plasma protein and 6-7% of the platelets. At the reduced flow rate (higher
 drug removal) the platelet morphology score dropped appreciably. We did
 not see any "fines" coming off the charcoal column.
 The ion exchange column clearly removed significant amounts of AMT at low
 flow rate, but not as much as the charcoal. This column did not appear to
 remove any plasma protein and platelet loss was higher than with the
 charcoal. The platelets did not appear to be affected by the ion exchange
 resin.
 EXAMPLE NO. 2
 In this example, two more AMT removal studies were performed using
 biobeads, one with 5.5 grams of 100-200 mesh biobeads and the other with
 7.5 grams of 20-50 mesh biobeads.
 One unit (50-60 mL) of platelets (in lactated ringers) containing about 20
 ug/mL of AMT was pumped through each column at a rate of 7 mL/min. Both
 columns removed all measurable AMT, but the 20-50 mesh column material
 yielded a "cleaner" HPLC output. The platelet loss for the 100-200 mesh
 column was 40% and for the 20-50 mesh was 28%. Total protein was reduced
 by 13% in the 100-200 mesh column and by 32% in the 20-50 mesh. The
 platelet morphology for the 100-200 mesh column was unchanged passing
 through the column at 355, and for the 20-50 mesh column the morphology
 changed from 130 to 115. It should be noted that the unit of platelets
 used for the 20-50 mesh biobead column had low platelet counts, bad
 platelet morphology and low protein content. The columns did not appear to
 shed any "fines", nor did the beads swell.
 The biobeads removed AMT as well as the activated charcoal tested in
 Example No. 1.
 EXAMPLE NO. 3
 The following method was performed on ten units of fresh frozen plasma,
 which had been thawed using an Instacool plasma thawer. An approximately
 12 ml sample was collected from each unit as an untreated control sample
 and aliquoted into tubes for testing. The tubes were labeled with the
 protocol number, the sample letter and untreated. These units were stored
 frozen (-80.degree. C..+-.10.degree. C.) until analyzed.
 Treated Samples
 The following procedure was performed on ten units of fresh frozen plasma,
 which had been thawed using the Instacool plasma thawer. An approximately
 12 ml untreated sample was removed from each unit, aliquoted and stored
 frozen (-80.degree. C..+-.10.degree. C.) until testing. Each unit was
 sterile connected and added to a container containing methylene blue.
 These units were labeled K-T. Each methylene blue treatment bag (PL732)
 was wrapped with aluminum foil and placed on a rotator (Scientific
 Products Multipurpose rotator Model 151) at room temperature and mix
 end-over-end at 40-60 rpm for 60 minutes. After mixing, the units were
 kept in aluminum foil and at room temperature prior to irradiation.
 An approximately 16 ml pretreatment sample was removed from each unit and
 divided into a 4 ml aliquot for methylene blue testing. Prior to
 irradiation of the plasma units, the light output delivered by the
 irradiation box was measured. The light output was recorded. The methylene
 blue plasma mixture was irradiated with the LED light source. The LED
 light source was placed on top of a horizontal rotator at a speed of 60
 rpm. All units were irradiated with red light for 8 J/cm.sup.2 exposure.
 The start and stop times were noted.
 An approximately 16 ml post treatment sample was removed from each unit and
 divided into a 4 ml aliquot for methylene blue testing. The remaining
 plasma in each plasma unit was passed through a methylene blue removal
 cartridge in the removal set of FIG. 1 with a plasma expresser. The
 removal cartridge included biobeads obtained from Biorad Laboratories and
 sold under the name Macro-Prep.RTM. t-butyl HIC. An approximately 16 ml
 post removal sample was aseptically removed from each unit and divided
 into a 4 ml aliquot for methylene blue testing.
 The following data was generated. FIGS. 2-9 graphically illustrate the
 data.
 TABLE 1
 Removal of Methylene Blue (MB) in ug/ml With Biobead Column
 1 uM = .374 ug/ml post post
 Test Sample untreated pretreatment treatment removal
 MB K NT 0.308 0.39 NRQ
 MB L NT 0.316 0.365 NRQ
 MB M NT 0.409 0.363 NRQ
 MB N NT 0.368 0.329 NRQ
 MB O NT 0.419 0.353 NRQ
 MB P NT 0.401 0.348 NRQ
 MB Q NT 0.422 0.306 NRQ
 MB R NT 0.426 0.409 NRQ
 MB S NT 0.43 0.344 NRQ
 MB T NT 0.292 0.384 NRQ
 *NRQ = No recoverable quantity
 TABLE 2
 Effect of Column Removal of Methylene Blue on Prothrombin Time
 post post
 Test Sample untreated pretreatment treatment removal
 PT K 12 12 12.2 13.8
 PT L 11.9 11.8 12.4 11.9
 PT M 12.2 12.5 13.7 13.7
 PT N 11.5 11.5 11.8 11.4
 PT O 12.2 12.1 15.1 12.1
 PT P 13.6 12.5 13.4 12.5
 PT Q 11.7 12.1 13.8 12.1
 PT R 11.6 13.2 15.8 13.7
 PT S 11.8 12.1 13.8 13.2
 PT T 11.7 14.2 13.1 11.8
 AVG 12.02 12.4 13.51 12.62
 SD 0.603 0.782 1.249 0.900
 TABLE 2
 Effect of Column Removal of Methylene Blue on Prothrombin Time
 post post
 Test Sample untreated pretreatment treatment removal
 PT K 12 12 12.2 13.8
 PT L 11.9 11.8 12.4 11.9
 PT M 12.2 12.5 13.7 13.7
 PT N 11.5 11.5 11.8 11.4
 PT O 12.2 12.1 15.1 12.1
 PT P 13.6 12.5 13.4 12.5
 PT Q 11.7 12.1 13.8 12.1
 PT R 11.6 13.2 15.8 13.7
 PT S 11.8 12.1 13.8 13.2
 PT T 11.7 14.2 13.1 11.8
 AVG 12.02 12.4 13.51 12.62
 SD 0.603 0.782 1.249 0.900
 TABLE 4
 Effect of Column Removal on Factor IX
 post post
 Test Sample untreated pretreatment treatment removal
 Factor IX K 117 92 94 96
 Factor IX L 100 87 76 87
 Factor IX M 61 59 60 54
 Factor IX N 79 75 81 69
 Factor IX O 68 75 72 65
 Factor IX P 70 63 45 51
 Factor IX Q 71 67 64 55
 Factor IX R 72 59 70 68
 Factor IX S 88 88 87 71
 Factor IX T 84 82 76 66
 AVG 81 74.7 72.5 68.2
 SD 16.964 12.338 13.986 14.227
 TABLE 4
 Effect of Column Removal on Factor IX
 post post
 Test Sample untreated pretreatment treatment removal
 Factor IX K 117 92 94 96
 Factor IX L 100 87 76 87
 Factor IX M 61 59 60 54
 Factor IX N 79 75 81 69
 Factor IX O 68 75 72 65
 Factor IX P 70 63 45 51
 Factor IX Q 71 67 64 55
 Factor IX R 72 59 70 68
 Factor IX S 88 88 87 71
 Factor IX T 84 82 76 66
 AVG 81 74.7 72.5 68.2
 SD 16.964 12.338 13.986 14.227
 TABLE 6
 Effect of Column Removal on Factor VII
 post post
 Test Sample untreated pretreatment treatment removal
 Factor VII K 103 95 92 104
 Factor VII L 129 119 119 116
 Factor VII M 63 57 57 61
 Factor VII N 87 84 82 93
 Factor VII O 89 85 89 90
 Factor VII P 59 63 50 60
 Factor VII Q 86 70 72 80
 Factor VII R 63 55 55 61
 Factor VII S 74 66 64 99
 Factor VII T 92 90 87 95
 AVG 84.5 78.4 76.7 85.9
 SD 21.324 20.001 21.250 19.723
 TABLE 6
 Effect of Column Removal on Factor VII
 post post
 Test Sample untreated pretreatment treatment removal
 Factor VII K 103 95 92 104
 Factor VII L 129 119 119 116
 Factor VII M 63 57 57 61
 Factor VII N 87 84 82 93
 Factor VII O 89 85 89 90
 Factor VII P 59 63 50 60
 Factor VII Q 86 70 72 80
 Factor VII R 63 55 55 61
 Factor VII S 74 66 64 99
 Factor VII T 92 90 87 95
 AVG 84.5 78.4 76.7 85.9
 SD 21.324 20.001 21.250 19.723
 TABLE 8
 Effect of Column Removal on Fibrinogen
 post post
 Test Sample untreated pretreatment treatment removal
 Fibrinogen K 341 290 276 281
 Fibrinogen L 308 285 261 248
 Fibrinogen M 250 235 204 185
 Fibrinogen N 377 345 318 329
 Fibrinogen O 285 273 248 252
 Fibnnogen P 200 189 149 137
 Fibrinogen Q 308 284 212 214
 Fibrinogen R 273 248 223 235
 Fibrinogen S 241 244 196 191
 Fibrinogen T 299 266 257 255
 AVG 288.2 265.9 234.4 232.7
 SD 50.861 41.162 47.664 53.994
 TABLE 8
 Effect of Column Removal on Fibrinogen
 post post
 Test Sample untreated pretreatment treatment removal
 Fibrinogen K 341 290 276 281
 Fibrinogen L 308 285 261 248
 Fibrinogen M 250 235 204 185
 Fibrinogen N 377 345 318 329
 Fibrinogen O 285 273 248 252
 Fibnnogen P 200 189 149 137
 Fibrinogen Q 308 284 212 214
 Fibrinogen R 273 248 223 235
 Fibrinogen S 241 244 196 191
 Fibrinogen T 299 266 257 255
 AVG 288.2 265.9 234.4 232.7
 SD 50.861 41.162 47.664 53.994
 TABLE 10
 Effect of Column Treatment of Control
 Samples on Fibrinogen, Factor V and Factor VII
 Sample Fibrinogen Factor V Factor VII
 Reference 200-400 50-150% 65-135%
 range mg/dl
 A untreated 281 82 95
 B untreated 249 114 144
 C untreated 202 79 103
 D untreated 302 62 76
 E untreated 399 87 71
 F untreated 233 96 82
 G untreated 279 93 87
 H untreated 263 58 113
 I untreated 299 60 80
 J untreated 240 111 98
 AVG 274.7 84.2 94.9
 SD 53.614 20.077 21.584
 TABLE 10
 Effect of Column Treatment of Control
 Samples on Fibrinogen, Factor V and Factor VII
 Sample Fibrinogen Factor V Factor VII
 Reference 200-400 50-150% 65-135%
 range mg/dl
 A untreated 281 82 95
 B untreated 249 114 144
 C untreated 202 79 103
 D untreated 302 62 76
 E untreated 399 87 71
 F untreated 233 96 82
 G untreated 279 93 87
 H untreated 263 58 113
 I untreated 299 60 80
 J untreated 240 111 98
 AVG 274.7 84.2 94.9
 SD 53.614 20.077 21.584
 TABLE 12
 Effect of Column Treatment of Control Samples on
 Prothrombin and Activated Partial Thromboplastin Time (APTT)
 Prothrombin APTT
 Sample Time (sec) (sec)
 Reference
 range
 A untreated 12.3 30.7
 B untreated 11.6 30.8
 C untreated 12 31.5
 D untreated 12.1 31
 E untreated 11.7 28.4
 F untreated 12.4 27.1
 G untreated 11.7 25.1
 H untreated 12.5 28
 I untreated 12.9 28.2
 J untreated 11.5 26.5
 AVG 12.07 28.7
 SD 0.455 2.179
 After flowing through the cartridge less than 4 nanograms/ml of methylene
 blue and photoproducts were present in the blood. It should be noted that
 prior to removal, the blood unit contained 400 nanograms/ml methylene
 blue. By way of example for a 70 Kg man receiving 2 liters of methylene
 blue treated fresh frozen plasma he would receive, after removal pursuant
 to the present invention, 114 ng/Kg of methylene blue. This amounts to
 1/44,000that of normal intravenous clinical dose. This reduced level
 effectively eliminates any toxicity concerns.
 As illustrated in FIGS. 2-9, except for with respect to Factor XI, the
 removal step does not remove components from the plasma. FIGS. 2-9
 illustrate, graphically content of specific components in: reference
 plasma; post-thaw; pretreatment; post treatment; and post removal.
 Specifically, FIGS. 2-9 graphically illustrate, content of: Fibrinogen;
 Factor V; Factor VII; Factor VII:C; Factor IX; Factor XI; prothrombin; and
 activated partial thromboplastin time, respectively. As illustrated, the
 method of the present invention can be used without destroying the
 therapeutic benefits of the blood to be transfused.
 It should be understood that various changes and modifications to the
 presently preferred embodiments described herein will be apparent to those
 skilled in the art. Such changes and modifications can be made without
 departing from the spirit and scope of the present invention and without
 diminishing its attendant advantages. It is therefore intended that such
 changes and modifications be covered by the appended claims.