Restoration of in vitro responses in platelets stored in plasma

Conventional platelet storage in a blood bank is up to 5 days at room tempe rature in plasma. I We investigated the optimal medium for assessing the qu ality of stored platelets by comparing in vitro test responses after resusp ension in autologous plasma prepared from platelet-rich plasma after 5 days of storage at room temperature, autologous plasma stored cell-free for 5 d ays at room temperature, or autologous plasma stored cell-free for 5 days a t -20 degrees C. Five-day-old platelets were prepared from aliquots of the same unit and resuspended in 1 of the 3 plasma preparations. The platelet-p lasma mixtures were monitored for changes in pH, mean platelet volume, hypo tonic shock response, P-selectin expression, and aggregation. There were st atistically significant differences between platelets resuspended in origin al plasma and platelets resuspended in either plasma stored cell-free at ro om temperature or frozen, with regard to hypotonic shock response, agonist- induced aggregation, and P-selectin expression. Plasma stored with platelet s for 5 days yielded inferior platelet function test responses when? compar ed with plasma stored cell-free at room temperature or frozen. Therefore, f or direct comparison of platelet responses following novel storage methods, the resuspending plasma should be stored under the same conditions as the control platelet unit.