Currently, apheresis platelets are stored at room temperature and have a shelf life of 5 days which makes them susceptible to bacterial contamination and numerous platelet storage lesions. Platelet additive solutions, collection systems, and storage bags may also affect the shelf life of platelets.
Here is Dr. Slichter who led this study:
“One of the major limitations in transfusion medicine is the extremely short storage time of platelets, so we undertook this study to try and determine if platelets would store better in an additive solution then they stored in plasma.”
The research team used three different apheresis systems to collect the platelets in either plasma or Plasmalyte, which is a platelet additive solution. In addition, two different types of storage bags were compared.
When using the Haemonetics collection system and bags to collect platelets in Plasmalyte, researchers could extend platelet storage to 13 days verses only 7 days with Trima collected platelets. Haemonetic collected platelets had a recovery rate of 65% and a survival rate of 55% compared to autologous fresh platelets. This is very close to meeting the FDA storage requirements. While recoveries and survival rates decreased by about half just by switching the type of storage bag used for platelets stored in Plasmalyte, the type of bag did not matter when platelets were stored in plasma.
Dr. Slichter summarizes: “I think the key points are that we can do extended platelet storage under conditions yet to be optimized, but it’s clearly possible. The other major finding is that the lifespan of the platelet is not intrinsic to the cell because in vivo the platelets live 8-9 days.”
While fresh radiolabeled autologous platelets had a lifespan of 8-9 days, the research team found that platelet viability could be extended to almost 18 days by first storing platelets in vitro for 13 days.
This study shows that we may be able to increase the storage time of platelets. Future studies are needed to evaluate bacterial contamination and confirm the best collection systems and bags.
We’ll be back with another edition of Transfusion News on February 15th. Thanks for joining us.
Slichter S, Corson J, Jones MK, Christoffel T, Pellham E, Bailey SL, Bolgiano D: Exploratory studies of extended storage of apheresis platelets in a platelet additive solution (PAS). Blood 2014;123:271-280.