Effect of storage of platelet concentrates in PAS-B, PAS-C, or plasma on transfusion reactions.

Background: Reports on the clinical consequences of longer storage time of platelet concentrates are contradictory. The objective of this study was to assess whether longer storage times are associated with a higher risk of transfusion reactions.

Study Design And Methods: We gathered storage times of pooled platelet concentrates related to transfusion reactions reported to the national hemovigilance office from 2004 to 2015. These were combined with storage times of platelet concentrates in the reference population to compare incidences of transfusion-associated circulatory overload, transfusion-related acute lung injury, allergic reactions, febrile nonhemolytic reactions, and "other" reactions between storage time categories.

Results: A total of 567,053 platelet concentrates and 1870 transfusion reactions were analyzed. Among platelet additive solution (PAS)-B platelet recipients, the odds ratio of a storage time of 4 to 5 days compared to 1 to 3 days was 1.60 (95% confidence interval [CI], 1.17-2.18) for allergic, and 1.47 (1.09-1.98) for febrile reactions. For PAS-C platelet recipients, the odds ratio for allergic reactions was 3.78 (95% CI, 1.31-10.9) for 4 to 5 days, and 4.57 (95% CI, 1.57-13.4) for 6- to 7-day-old platelets when compared to 1- to 3-day-old units. In all other studied reaction types, no statistically significant association was observed in platelets in plasma, PAS-B, and PAS-C.

Conclusions: In plasma platelets, longer storage time was not associated with a higher incidence of transfusion reactions. In PAS platelets, longer storage time was associated with higher transfusion reaction incidences, in particular for allergic reactions with both PAS fluids and febrile reactions with PAS-B. This indicates that the effect of storage time is different for different reaction types and depends on the storage fluid.