Quantification of platelet activation status by analyzing P-selectin expression

Platelet activation status (PAS) is used for characterizing quality and fun ction of platelets in various experimental and clinical settings. In this s tudy, we created a set of platelet populations differing in PAS, using stim ulation of platelets with thrombin in a wide range of concentrations, and a nalyzed a number of how cytometric parameters, which characterize PAS by me asuring P-selectin (CD62) expression. We found that PAS of a platelet popul ation depends significantly on the specific parameters used for detecting C D62 expression and can differ several fold. We revealed the parameters whic h are more sensitive for distinguishing the differences between populations with similar low and similar high PAS. Selection of valid and sensitive fl ow cytometric parameters for PAS evaluation and distinguishing the differen ces between platelet populations with similar PAS can serve for diagnosis o f platelet-associated disorders and monitoring their course and therapeutic interventions. (C) 2000 Academic Press.