The U.S. Food and Drug Administration recently approved cold storage of platelets for up to 14 days for the treatment of actively bleeding patients when conventional platelets are not available. Platelets have been stored at room-temperature since studies in the late 60s showed that cold-stored platelets are rapidly cleared from circulation post-transfusion. However, more recent data on the effectiveness of cold-stored platelets are unclear. To evaluate the function of platelets stored for the maximum duration at cold and room temperatures, Kogler et al. randomized ten healthy adults for a crossover study. Volunteers, treated with acetylsalicylic acid (to block endogenous platelet aggregation) were transfused with autologous platelets stored for either 7 days at room temperature or 14 days in cold storage; platelet function/aggregation and lipid metabolites were measured. A second round of platelet transfusions with alternative maximum storage conditions allowed study volunteers to also serve as controls. Cold-stored platelets were unable to restore platelet function at 1, 4 or 24-hours post-transfusion; room temperature-stored platelets, however, reversed platelet inhibition significantly better at 1 and 24 hours compared to cold-stored platelets (p<0.02 for both). In addition, cold-stored platelets were more procoagulant (as measured by increased thrombin generation) than room temperature-stored platelets one hour after transfusion. Lipid metabolites (which serve as critical mediators of platelet function) were variable after storage in bags and post-transfusion, but concentrations of different metabolites were found to predict the aggregation of either cold- or room temperature-stored platelets. Ongoing clinical trials will help determine the effectiveness of room temperature-stored platelets in bleeding patients.
References:
- Kogler VJ, Miles JA, Özpolat T, Lawrence Bailey S, et al. Platelet dysfunction reversal with cold-stored vs room temperature–stored platelet transfusions. Blood 2024; 143(20); 2073-2088.
- Reddoch-Cardenas KM and MA Meledeo. Platelets: let’s chill until more data arrive. Blood 2024; 143(20); 2019-2020.
