COAGULATION-FACTOR ACTIVATION IN STORED PLATELET CONCENTRATES IS MODULATED BY THE PLATELETS

To assess alterations in coagulation proteins in stored platelet conce ntrates, we used a series of platelet parameters and measures of coagu lation activation to compare samples collected before unit donation, d uring the processing of platelet concentrates (PC) fi om CPDA-1 blood. and in storage up to 5 days as well as stored platelet-poor plasma ( PPP). Storage-dependent increases in activated pal-tial thromboplastin time and prothrombin time were seen in both PC and PPP. However, FVII , FXI, FXII, kallikrein activity and prothrombin F1,2 levels remained unchanged in stored PC. Surprisingly, in stored PPP, significant alter ations in FXII, FVII, kallikrein and prothrombin F1.2 levels were seen . Platelet morphology and surface marker studies demonstrated platelet activation during storage. These data suggest that the presence of pl atelets in the CLX storage container partially suppresses coagulation activation at significant cost to platelet viability.