U.S. patent application number 10/295772 was filed with the patent office on 2003-08-14 for method for extending the useful shelf-life of refrigerated red blood cells by nutrient supplementation.
Invention is credited to Bitensky, Mark W., Yoshida, Tatsuro.
Application Number | 20030153074 10/295772 |
Document ID | / |
Family ID | 23298102 |
Filed Date | 2003-08-14 |
United States Patent
Application |
20030153074 |
Kind Code |
A1 |
Bitensky, Mark W. ; et
al. |
August 14, 2003 |
Method for extending the useful shelf-life of refrigerated red
blood cells by nutrient supplementation
Abstract
There is provided methods and compositions for the storage of
red blood cells. The compositions are metabolic supplements which
are preferably added to refrigerated red blood cells suspended in
an additive solution. Red blood cells are preferably stored under
conditions of oxygen-depletion. Metabolic compositions comprises
pyruvate, inosine, adenine, and optionally dibasic sodium phosphate
and/or monobasic sodium phosphate.
Inventors: |
Bitensky, Mark W.; (Waban,
MA) ; Yoshida, Tatsuro; (West Newton, MA) |
Correspondence
Address: |
Paul D. Greeley, Esq.
Ohlandt, Greeley, Ruggiero & Perle, L.L.P.
10th Floor
One Landmark Square
Stamford
CT
06901-2682
US
|
Family ID: |
23298102 |
Appl. No.: |
10/295772 |
Filed: |
November 15, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60332409 |
Nov 16, 2001 |
|
|
|
Current U.S.
Class: |
435/374 ;
422/40 |
Current CPC
Class: |
A61P 43/00 20180101;
A01N 1/02 20130101; A01N 1/0226 20130101 |
Class at
Publication: |
435/374 ;
422/40 |
International
Class: |
C12N 005/00; C12N
005/02 |
Claims
What is claimed is:
1. A method for the storage of red blood cells comprising: adding a
metabolic supplement at least once to red blood cells; and storing
said red blood cell under refrigeration.
2. A method according to claim 1, wherein said red blood cells are
packed red blood cells or suspended red blood cells in an additive
solution.
3. A method according to claim 1, wherein said red blood cells are
refrigerated at the time the metabolic supplement is added.
4. A method according to claim 1, further comprising first adding
an additive solution to said red blood cells forming a suspension
of red blood cells.
5. A method according to claim 4, wherein said additive solution is
selected from the group consisting of AS-3, EAS61, OFAS1, OFAS3,
and mixture thereof.
6. A method according to claim 1, further comprising storing said
red blood cells under oxygen-depleted refrigeration.
7. A method according to claim 2, further comprising mixing whole
blood with an anticoagulant solution, concentrating the whole blood
cells from said whole blood and separating the plasma thereby
creating a mass of packed red blood cells.
8. A method according to claim 1, wherein said metabolic supplement
comprises pyruvate, inosine, adenine and optionally dibasic sodium
phosphate and/or monobasic sodium phosphate.
9. A method for extending the storage life of refrigerated packed
red blood cells which comprises adding a metabolic supplement to
said refrigerated packed red blood cells.
10. A method for extending the storage life of refrigerated red
blood cells comprising: adding a first solution to packed red blood
cells; storing said red blood cells in oxygen-depleted
refrigeration; and adding a second solution to said red blood
cells.
11. A method according to claim 10, wherein said first solution is
an additive solution.
12. A method according to claim 10, wherein said additive solution
is selected from the group consisting of AS-3, EAS61, OFAS1, and
OFAS3.
13. A method according to claim 10, wherein said second solution is
a metabolic supplement.
14. A method according to claim 13, wherein said metabolic
supplement comprises pyruvate, inosine, adenine and optionally
dibasic sodium phosphate and/or monobasic sodium phosphate.
Description
[0001] This application claims priority from U.S. Provisional
Application No. 60/332,409, filed Nov. 16, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to the preservation of blood
in liquid form. More particularly, the present invention relates to
enhancement of the shelf-life of oxygen-depleted refrigerated
storage of red blood cells. Still more particularly, compositions
and methodology involving nutrient or metabolic supplementation of
red blood cells stored in liquid form in oxygen-depleted
refrigeration are provided. This invention was made with partial
support by the United States Office of Naval Research, Contract No.
N00014-98-1-0451. The Government has certain rights in the
invention.
DESCRIPTION OF THE PRIOR ART
[0003] By way of background, currently the supplies of liquid blood
are limited by storage. Stored blood expires after about 42 days of
refrigerated storage. Red blood cells may, for example, be stored
under refrigeration at a temperature above freezing (4.degree. C.)
as packed blood cell preparations. Red blood cells may be
concentrated from whole blood with separation of the liquid blood
component (plasma). Expired blood cannot be used and is discarded.
There are periodic shortages of blood that occur due to donation
fluctuation, emergencies and other factors. The logistics of blood
supply and distribution impact the military, especially during
times of combat, and remote hospitals or medical facilities. There
is currently a need for the storage of autologous blood to avoid
the significant risks of infection associated with non-autologous
donor blood. Patients currently cannot collect and store with
current technology enough autologous blood for certain pre-planned
surgeries, including hip replacement, organ transplantation and the
like.
[0004] Storage of frozen blood is known in the art but such frozen
blood has limitations. For a number of years, frozen blood has been
used by blood banks and the military for certain high-demand and
rare types of blood. However, frozen blood is difficult to handle.
It must be thawed which makes it impractical for emergency
situations. Once blood is thawed, it must be used within 24
hours.
[0005] U.S. Pat. No. 4,769,318 to Hamasaki et al. is directed to
additive solutions for blood preservation and activation. U.S. Pat.
No. 5,624,794 to Bitensky et al. and also U.S. Pat. No. 6,162,396
to Bitensky et al. are directed to the storage of red blood cells
under oxygen-depleted conditions. U.S. Pat. No. 5,789,151 to
Bitensky et al. is directed to blood storage additive
solutions.
[0006] Additive solutions for blood preservation and activations
are known in the art. For example, Rejuvesol (available from enCyte
Corp., Braintree, Mass.) is add to blood after cold storage (i.e.,
4.degree. C.) just prior to transfusion or prior to freezing (i.e.,
at -80.degree. C. with glycerol) for extended storage.
[0007] In light of current technology, there still remains a
long-felt need for the extension of the useful shelf-life of stored
liquid blood, especially for extension technology that is
relatively inexpensive, easy to handle, and that provides
significantly extended long-term storage.
[0008] Accordingly, it is an object of the present invention to
provide a method for extended storage of red blood cells.
[0009] It is another object of the present invention to provide
nutrient or metabolic supplements useful with the storage of red
blood cells.
[0010] Another object of the present invention to provide a method
for extending the storage of red blood cells using oxygen-free
additive solutions and oxygen removal.
[0011] These and other objects and advantages of the present
invention and equivalents thereof, are achieved by the methods and
compositions of the present invention described herein and manifest
in the appended claims.
SUMMARY OF THE INVENTION
[0012] The present invention provides methods and compositions for
extending the useful shelf-life of red blood cells. The method of
the invention comprises adding a metabolic supplement to packed red
blood cells, adding an additive solution, preferably an oxygen-free
additive solution, to said red blood cells, and storing said red
blood cells at a temperature above freezing, preferably 4.degree.
C., under conditions of oxygen-depletion. Metabolic supplement
compositions of the invention comprise pyruvate, inosine, adenine,
monobasic and dibasic phosphate salts at a pH from about 5 to about
8. Rejuvesol, or modification thereof, may be used as a metabolic
supplement solution. Oxygen depletion may be effected by flushing
the red blood cells with an inert gas as described with oxygen
depleted refrigerated storage in U.S. Pat. No. 5,624,794 and U.S.
Pat. No. 6,162,396. Preferred oxygen-free additive solutions
comprise modifications of EAS61 (Hess et al., Transfusion 40:
1007-1011), and OFAS1 (U.S. Pat. No. 5,789,151). A preferred
oxygen-free additive solution is OFAS3. The present invention
extends the useful shelf life of refrigerated packed red blood
cells from the current approximately 6 week limit to about 12 to
about 20 weeks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows the effect of pH and oxygen depletion on
cellular ATP levels of red blood cells in OFAS3.
[0014] FIG. 2 shows the effect of pH and oxygen depletion on the
percentage of red blood cells exposing phosphotidylserine in
OFAS3.
[0015] FIG. 3 shows the effect of pH and oxygen depletion on red
blood cell hemolysis in OFAS3.
[0016] FIG. 4 shows the effect on red blood cell ATP levels of
metabolic supplements added at different pH's in the presence or
absence of oxygen.
[0017] FIG. 5 shows the effect on red blood cell 2,3-DPG levels of
metabolic supplements added at different pH's in the presence or
absence of oxygen.
[0018] FIG. 6 shows the effect on the percentage of red blood cells
exposing phosphotidylserine of addition of metabolic supplements at
different pH's in the presence and absence of oxygen.
[0019] FIG. 7 shows the effect on vesicle protein production of red
blood cells of addition of metabolic supplements at different pH's
in the presence or absence of oxygen.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In its most general form, the present invention provides
methods and compositions extending the useful shelf life of
refrigerated red blood cells. The present invention more than
doubles the useful shelf life of red blood cells and overcomes
current limitations in the blood industry by providing longer and
less perishable blood supplies.
[0021] Metabolic supplementation is used commercially. For example,
Rejuvesol is indicated for use at 37.degree. C. and a 1 hour
rejuvenation of stored blood just prior to transfusion or just
prior to freezing in glycerol. The present invention describes
addition of metabolic supplement during refrigerated storage
combined with the use of oxygen free additive solution (i.e.,
OFAS3) and oxygen removal. With this approach, unprecedented
results have been obtained. For example, red blood cell storage
well beyond the current 6-week limit for 12 or up to 20 weeks at
4.degree. C. with levels of 2-3 DPG and ATP that are above those
found in freshly drawn blood. A rationale for this efficacy is
suggested or inferred from the fact that in the cold, earlier
enzymatic steps of the glycolytic pathway are more seriously
impaired than the later enzymatic steps. Thus, by bypassing the
earlier enzymatic steps of glycolysis with the addition of
metabolic intermediates that directly feed or serve as substrates
for the later enzymatic steps, we have been able to significantly
boost the production of ATP and 2-3 DPG. The fact that these
substrates readily traverse the erythrocyte membrane at cold
temperature (i.e., 4.degree. C.) is clearly demonstrated by the
experimental results obtained which are presented herein. The use
of Rejuvesol in its current formulation does incur the need for a
simple wash step prior to transfusion.
[0022] Metabolic supplementation of the invention is effected at
least once, preferably during oxygen-depleted refrigerated storage
(i.e., 4.degree.) of red blood cells (c.f., U.S. Pat. Nos.
5,624,794; 6,162,396), along with oxygen-free additive solution,
preferably OFAS3 or modification thereof. Blood units are not
warmed. EAS61 and OFAS1 are additive solutions known in the
art.
[0023] Metabolic supplement is added to refrigerated red blood
cells. A first addition is made within 6-10 weeks of storage. A
second addition is optionally added within 11-20 weeks of
storage.
[0024] Metabolic supplement solution composition is presented in
Table 1.
1 TABLE 1 Concentration Ingredient (g/unit of addition) Na pyruvate
0.1-2.0 Inosine 0.5-3.0 Adenine 0.01-1.0 Na phosphate dibasic 0-2.0
Na phosphate monobasic 0-2.0 pH 5.5-8.0
[0025] The concentrations, given in mM units, of various blood
additive solutions are presented in Table 2.
2 TABLE 2 Ingredient AS-3 AS-1 OFAS1 EAS61 OFAS3 Adenine 2.2 2 2 2
2 Dextrose 61 122 110 110 110 Mannitol -- 42 65 55 55 NaCl 70 154
-- 26 26 Na citrate 20 -- 20 13 -- Citric acid 2 -- -- -- --
Na.sub.2HPO.sub.4 -- -- -- 12 12 NaH.sub.2PO.sub.4 20 -- 20 -- --
pH 7.2* 8.3 6.5* vol. added 200 250 200 200 (mL) final Hct
.about.40 .about.35 .about.40 .about.40 *pH adjusted with NaOH
[0026] Preferred concentration ranges of OFAS3 are presented in
Table 3.
3 TABLE 3 Ingredient Range (mM) Adenine 0.5-4.0 Dextrose 50-150
Mannitol 20-70 NaCl 0-100 NaH.sub.2PO.sub.4 2-20 NH.sub.4Cl 0-30 pH
5.5-7.7 mL added 100-300
[0027] Final Hct 30-50
[0028] The following Examples are illustrative of the invention and
are not intended to be limitative thereof.
EXAMPLE 1
OFAS3: Effect of pH and Oxygen Depletion on Cellular ATP Levels
[0029] Results of experimentation to determine the effect of pH and
oxygen depletion on cellular ATP levels with blood samples
containing oxygen-free additive solution (OFAS3) are presented in
FIG. 1. Each point on the graph is the average of 6 subjects. For
comparative purposes, AS1 and AS3, the current U.S. standard
additive solution, serve as a control. There is a large variability
in the values between different test subjects. In order to see the
effect of pH, P values-(t-test for paired two samples for means)
were calculated and are presented in Table 4.
4TABLE 3 Pairwise Test of ATP Values (For Oxygen Depleted Storage
at Various pH's) Time P(T < = t) one-tail P(T < = t) one-tail
(Days) pH 6.5 vs. pH 8.3 pH 6.5 vs. pH 7.4 9 0.002 0.007 13 0.032
0.327 20 0.008 0.116 28 0.001 0.104 41 0.072 0.072 49 0.023 0.111
66 0.008 0.149 83 0.007 0.147 99 0.008 0.388
[0030] Although there are large subject to subject variations in
ATP levels, there are significant differences between pH 6.5 and pH
8.3. These data show that oxygen depletion further enhances ATP
levels as much as 33% by week 3 and 38% by week 14. The increase in
ATP levels is dramatically enhanced when red blood cells are stored
in oxygen depleted conditions. The best result was obtained with
additive solution (OFAS3) at pH 6.5 with oxygen depletion.
EXAMPLE 2
OFAS3: Effect of pH and Oxygen Depletion on % of Cells Exposing
Phosphotidylserine
[0031] Results of experimentation to determine the effect of pH and
oxygen depletion on the % of red blood cells exposing
phosphotidylserine with samples containing oxygen-free additive
solution (OFAS3) are presented in FIG. 2. Data were obtained by
flow cytometer measurements using FITC-Annexin IV probe. Each point
on the graph is the average of 6 subjects. There is a significant
reduction in exposed phosphotidylserine after 10 weeks when pH 8.3
and pH 6.5 blood samples, both oxygen depleted, are compared.
EXAMPLE 3
OFAS3: Effect of pH and Oxygen Depletion on Red Blood Cell
Hemolysis
[0032] Results of experimentation to determine the effect of pH and
oxygen depletion on red blood cell hemolysis with blood samples
containing oxygen-free additive solution (OFAS3) are presented in
FIG. 3. Each point on the graph is the average of 6 subjects. Three
different pH's were tested, pH 6.5, pH 7.4, and pH 8.3, with
control cultures that were not oxygen-depleted. At week 16, the pH
6.5 oxygen-depleted refrigerated red blood cell storage system has
the lowest extent of hemolysis.
EXAMPLE 4
Addition of Metabolic Supplements During Refrigerated
Oxygen-Depleted Red Blood Cell Storage: Effect of Metabolic
Supplements Added at Different pH's in the Presence or Absence of
Oxygen on Cellular ATP Levels
[0033] Results of experimentation to determine the effect of
addition of metabolic supplements added during refrigerated,
oxygen-depleted storage of red blood cells at different pH's in the
presence or absence of oxygen on cellular ATP levels, are
graphically presented in FIG. 4. Two different pH's were tested, pH
6.5 and pH 8.3, with control cultures that are not oxygen depleted.
Metabolic supplement, Rejuvesol, was added to cultures as indicated
by the arrows in FIG. 4, which correspond approximately to
additions during cold storage at 9, 14, and 21 weeks respectively.
These data show that ATP levels are significantly increased each
time the cold fuel/metabolic supplement is added. The highest ATP
levels are sustained with pH 6.5 additive solution under oxygen
depleted conditions. ATP levels are sustained near or above day 0
values throughout 22 weeks of storage with the additions of cold
fuel.
EXAMPLE 5
Addition of Metabolic Supplements During Refrigerated
Oxygen-Depleted Red Blood Cell Storage: Effect of Metabolic
Supplements Addition at different pH's in the Presence and Absence
of Oxygen on Cellular 2,3-DPG Levels
[0034] Results of experimentation to determine the effect of
addition of metabolic supplements during refrigerated,
oxygen-depleted red blood cell storage in the presence or absence
of oxygen on cellular 2,3-DPG levels, are presented in FIG. 5. Each
point on the graph is the average of 6 subjects. Two different pH's
were evaluated, pH 6.5 and pH 8.3. Control cultures are not
oxygen-depleted. Metabolic supplement, Rejuvesol, was added at the
time indicated by the arrows, which correspond approximately to 8,
14, and 20 weeks respectively. These data show that oxygen
depletion elevates 2,3-DPG levels significantly at the start of
storage, without addition of metabolic supplements. Addition of
metabolic supplements increases 2.3-DPG levels slowly at 4.degree.
C., and keeps these levels well above day 0 values, thus enhancing
oxygen delivery capacity of the transfused blood.
EXAMPLE 6
Addition of Metabolic Supplements During Refrigerated
Oxygen-Depleted Red Blood Cell Storage: Effect of Metabolic
Supplements Addition at different pH's in the Presence and Absence
of Oxygen on the % of Red Blood Cells Exposing
Phosphotidylserine
[0035] Results of experimentation to determine the effect of
addition of metabolic supplements during refrigerated,
oxygen-depleted red blood cell storage in the presence or absence
of oxygen on the percent of red blood cells exposing
phosphotidylserine are presented in FIG. 6. Data were obtained from
measurements by flow cytometer using FITC-Annexin IV probe. Each
point on the graph represents the average of 6 subjects. Two
different pH's were evaluated, pH 6.5 and pH 8.3, with metabolic
supplement, Rejuvesol, added at the time indicted by the arrows
which correspond to additions at approximately 8.6, 14, and 20
weeks. Control cultures are not oxygen-depleted. Phosphotidylserine
is gradually exposed during refrigerated (4.degree. C.). However,
addition of metabolic supplements reverses this exposure. This
experiment has been repeated three times with similar results. The
lowest levels of exposure were seen with pH 6.5 storage buffer with
oxygen depletion.
EXAMPLE 7
Addition of Metabolic Supplements During Refrigerated
Oxygen-Depleted Red Blood Cell Storage: Effect of Metabolic
Supplements Addition at different pH's in the Presence and Absence
of Oxygen on Vesicle Production
[0036] Results of experimentation to determine the effect of
addition of metabolic supplements during refrigerated,
oxygen-depleted red blood cell storage in the presence or absence
of oxygen on the vesicle production are presented in FIG. 7. Each
point on the graph represents the average of 6 subjects. Two
different pH's were evaluated, pH 6.5 and pH 8.3, with metabolic
supplement, Rejuvesol, added at the time indicted by the arrows
which correspond to additions at approximately 8.6, 14, and 20
weeks respectively. Control cultures are not oxygen-depleted. It is
known that refrigerated red blood cells shed vesicles during
storage. Addition of metabolic supplements slows vesicle
production. In the system comprising metabolic supplementation
during oxygen-depleted refrigerated storage with oxygen-free
additive solution, the additive solution OFAS3 was shown to be the
most effective of such additives.
EXAMPLE 8
Twenty-Four-Hour In Vivo Post Transfusion Survival of Stored Red
Cell Units
[0037] Eight normal subjects each donated a unit of whole blood via
a standard, manual method on two separate occasions approximately 8
weeks apart. Subject requirements were the same as those that apply
for allogeneic blood donors as established by 21 CFR640.3 and the
Standards of the American Association of Blood Banks. These units
were processed via centrifugation to yield packed red cells via a
"soft spin" technique (2000 g*3 min) following holding at room
temperature for 1-2 hours, and 200 mL of an experimental additive
solution OFAS3 were added (Table 2) to yield a final hematocrit of
35-45%. These and all other manipulations of units involving
addition of solutions or sampling were accomplished via a sterile
connection device.
[0038] The test units were stored in an anaerobic environment
following multiple flushes to minimize the oxygen content of each
unit using highly purified Ar and H.sub.2 Following completion of
sampling, the test units were made anaerobic following the
procedure provided by the sponsor. Briefly, the units were
transferred to a 2000 mL transfer bag using the SCD. Sputtering
grade argon was introduced into the unit via a 0.22 micron filter
until the transfer bag was completely filled with gas/blood and
rotated 10 min at room temperature. Following this hold period, the
gas was expelled through the same 0.22 micron filter using a plasma
expressor and a vacuum line. This procedure was repeated 6 times,
and the unit was transferred to a standard PL146 red cell storage
bag with an Ar flush. The unit was then placed in an anaerobic
culture jar and 3 exchanges of the contents of the jar were
performed with Ar, the last consisting of 2 parts Ar, 1 part
scientific grade H.sub.2 before the jar was placed in a monitored
4.degree. C. refrigerator. When subsequent samples were taken via
the SCD, the storage jar again underwent gas replacement prior to
the unit being placed back in the refrigerator. Jars were flushed
weekly with Ar if no sampling occurred in that week. Control units
were stored in the same refrigerator without altering their gaseous
environment.
[0039] After 7 weeks of storage, test units underwent a metabolic
supplementation using a licensed solution (Rejuvesol, Cytosol
Laboratories, Braintree, Mass.); test units underwent an additional
metabolic supplementation at 11 weeks (if recoveries to date
indicated that continued storage was warranted, vida infra) The
contents of the bottle of metabolic supplement were aspirated via
needle and syringe and injected via a sampling port into a plastic
transfer bag that had been previously flushed with Ar and to which
had already been attached a 0.22 micron filter. The solution was
then transferred to the unit by sterile docking, and the unit was
promptly returned to refrigerated storage (without repeating the
gas exchange procedure and without incubation or washing).
[0040] Control units were utilized for radiolabeling and autologous
reinfusion at 10 weeks; test units were continued in the protocol
so long as the prior radiolabeled recovery suggested the continued
viability of the cells. In addition, for a radiolabeled recovery to
be conducted, the ATP must have been at least 50% of the Day 0
value, and the hemolysis must have been no more than 3.0% at the
preceding sampling.
[0041] Radiolabe]ing to allow for determination or in vivo red cell
recovery` was conducted according to published procedures [J. Nucl.
Med. 1975; 16:435-7] 10-20 .mu.CiNa.sub.2.sup.51CrO.sub.4 (Bracco,
Princeton, N.J.) were added to a 10 mL aliquot of the unit's cells
for 30 min. at room temperature followed by a single double-volume
saline wash. [Blood 1871; 38:378-86; Transfusion 1984; 24:109-14]
(Prior to labelling, cells from test units were washed four times
with a double volume saline wash to remove remaining constituents
of the rejuvenation solution.) These cells were injected
simultaneously with fresh autologous red cells that had been
labeled with 10-20 .mu.Ci .sup.99mTc pertechnetate after "tinning"
to determine the subject's red cell volume; [Dave, R. J., Wallacae,
M. e., eds. Diagnostic and investigational uses of radiolabeled
blood elements. Arlington: American Association of Blood Banks,
1987] labeled cells were washed once with 40 mL ice-cold saline.
Reinfusions were conducted promptly after labeling, and labeled
cells were kept on ice until then, Samples were taken from 5 to 30
min. and then at 24 h to determine circulating radioactivity. Red
cell volumes were determined by single and double label calculation
methods after correction for counting interference and .sup.99mTc
label elution prior to injection Results of a 24-hr in vivo post
tranfusion survival study of stored red cell units are presented in
Table 5. Hemolysis remained below 1% through 14 weeks of storage.
The maximum noted was 1.75% at 16 weeks in one unit.
5TABLE 5 volunteer A B C D E F G n Average std dev single layer 10
wks test 73.9 74.2 69.6 72.5 64.6 81.9 90.3 7 75.3 8.4 12 wks test
69.9 66.9 71.6 74.3 78.05 84.6 6 74.2 6.3 14 wks test 65.6 61.7
58.3 79.6 74.2 78.8 6 69.7 9.1 16 wks test 69.7 75.1 2 72.4 3.8 10
wks control 71.7 78.5 66.6 56.8 77.6 73.8 78.0 7 71.9 7.9 double
label 10 wks test 82.6 83.5 76.7 78.6 62.1 82.0 96.0 7 80.2 10.1 12
wks test 67.1 68.3 78.4 75.0 80.8 86.0 6 75.9 7.3 14 wks test 64.8
63.6 57.1 78.7 79.6 76.0 6 70.0 9.4 16 wks test 79.2 74.2 2 76.7
3.5 10 wks control 72.4 79.7 68.2 49.7 74.5 69.7 73.7 7 69.7 9.6
Note: 12-week data for subjects F and G are linearly extrapolated
from 10 and 14 week data Test units: Packed red cells were stored
under oxygen depleted conditions at 4C in OFAS3 storage solution. #
At weeks 7 and 11, metabolic supplements were added at 4C. Control
units: Packed red cells were stored in OFAS3 storage solution at 4C
without oxygen depletion or metablic supplement additions.
[0042] Although the present invention describes in detail certain
embodiments, it is understood that variations and modifications
exist known to those skilled in the art that are within the
invention. Accordingly, the present invention is intended to
encompass all such alternatives, modifications and variations that
are within the scope of the invention as set forth in the following
claims.
* * * * *