EDTA-dependent pseudothrombocytopenia: clinical aspects and laboratory tests

EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) is a phenomenon caused by EDTA-dependent anti-platelet antibody. This antibody induces platelet agglutination in vitro, resulting in a decrease in platelet counts. It is necessary for clinicians to consider the possible presence of PTCP in cases of patients having low platelet counts without any hemorrhagic tendency. In this article, we describe some aspects of EDTA-PTCP including, (1) characteristics of platelet agglutination, (2)possible mechanisms for antibody production, (3) several methods to determine the true platelet number, and also (4) a few similar phenomena induced by antibodies independent of EDTA.