Platelets and platelet function testing in children

Platelets play key roles in hemostasis as well as in the pathogenesis of arterial thrombosis. This review summarizes current knowledge of the physiology of pediatric platelets; similarities and differences with platelets from adults are discussed with regards to platelet characteristics, adhesion, activation and secretion, and aggregation. A number of tests of platelet function are reviewed: aggregometry; PFA-100; flow cytometry; and VerifyNow, as well as a test of global hemostasis, thrombelastography. The applications, advantages and shortcomings of these tests in children are described, including their use for monitoring the effects of antiplatelet drugs, which has been done almost exclusively in adult patients.