a.
FDA approval for the extension of frozen storage of red blood cells:
One of the things we hope to accomplish is to persuade the FDA to
allow for longer frozen storage of red blood cells. The FDA
has approved the frozen storage of red blood cells for up to 10 years.
However, our laboratory has provided data to the Navy Blood Program
Office and Armed Services Blood Program Office which shows that red
blood cells can be frozen for up to 37 years with no significant damage.
FDA is currently reviewing our submission for extension of the frozen
red blood cell storage and a decision is expected soon.
Military
significance: The Department of Defense currently has more
than 60,000 units of frozen red blood cells stockpiled. Several
thousand of these frozen red blood cell units are nearing the 10-year
outdate. FDA-approval of an extension in the acceptable period
for frozen storage of red blood cells will save the Department of
Defense the cost of replacing these high-quality frozen red blood
cells.
Civilian
significance: Like DOD, some civilian facilities
have also stockpiled frozen red blood cells for use in emergency
shortages and approval of this extension will also save them the
costs of replacing these red cells.
b.
FDA approval of a closed, automated system to glycerolize (freeze)
and deglycerolize (wash) red blood cells: Also as part of our
frozen red blood cell program, we have evaluated a new automated machine,
the Haemonetics Model 215, which the FDA considers a 'closed' system.
The term 'closed' means that there is no potential for bacterial contamination
to occur during the red blood cell freezing and washing procedures.
The current systems are considered 'open', and have the potential
for bacterial contamination occurring during either the freezing or
washing procedure, and the FDA has determined that these previously
frozen red blood cells can be stored for only 24 hours following thawing
and washing. The need for the limited 24-hour post-wash storage
period with the current systems is understandable. If the red
blood cells did become contaminated during the freezing or washing
procedures, the longer they are stored in the refrigerator following
washing, the better the chance the bacteria could repopulate and cause
a transfusion reaction. However, this limited post-wash
storage period requires that frozen red blood cells be thawed and
washed only when the need to use them within the 24 hour period is
certain. The new 'closed' system eliminates the potential for
bacterial contamination. Data provided to FDA by our laboratory
as part of a multi-center study have shown that red blood cells processed
using the Haemonetics 215 closed system can be stored for up to 15
days following washing with acceptable results. Based on these
data, the FDA has approved the Haemonetics 215 system with post-wash
storage of previously frozen red blood cells for 14 days following
washing. It is expected that this extension will result in an
increased use of frozen red blood cells in both the civilian and military
communities.
Military
significance: The Department of Defense currently
stockpiles frozen red blood cells for use in emergency situations.
This new, automated system will not only allow for increased post-wash
storage but will also increase productivity. Because the new
system is automated, 1 technician can operate 8 to 10 machines at
1 time.
Civilian
significance: Approval of a closed, automated system
with an extended post-wash storage period will simplify the use
of frozen red blood cells allowing civilian centers to use frozen
red blood cells for inventory control. This is especially
important in light of the recent American Red Cross blood shortages.
The
NBRL is attempting to obtain FDA approval for frozen platelets.
Platelets, the cells in the blood which are used to stop bleeding,
can be stored at room temperature for no more than 5 days. Platelets
cannot be stored in the refrigerator at 4 C because they undergo shape
changes that reduce their survival following transfusion. The
disadvantage of the warmer room temperature storage is that it increases
the risks of bacterial contamination. Our laboratory began evaluating
methods to freeze platelets in 1972. From that time to the present,
we have developed a relatively simple procedure to freeze platelets
with a chemical called dimethyl sulfoxide (DMSO) which allows for
frozen storage of the platelets at -80 C for up to 2 years.
The data we have obtained using this platelet freezing method have
been submitted to FDA and we are currently awaiting their response.
We are currently developing a method where we remove most of the DMSO
before the platelets are frozen, thereby eliminating the washing step
after freezing. This would significantly simplify the procedure
for use by the civilian and military communities.
Military
significance: The limited 5-day liquid storage period
does not allow enough time for the platelets to be collected at
fixed facilities and transported to the field. The Department
of Defense currently has stockpiled more than 60,000 units of frozen
red blood cells. Once our platelet program is FDA approved,
frozen platelets can be stockpiled along with frozen red blood cells.
The military would then be ensured of a supply of platelets adequate
for their needs.
Civilian
significance: Platelet availability in the civilian
community is also affected by their limited storage period.
Single-donor platelets are expensive to collect and a method is
needed to preserve them when quantities are high.
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