Platelet activation as a potential mechanism of GP IIb/IIIa inhibitor-induced thrombocytopenia

Abstract

The blockade of the platelet integrin glycoprotein (GP) IIb/IIIa has proved to be an effective antiplatelet therapy. Profound thrombocytopenia has repeatedly been described as an adverse effect in patients treated with GP IIb/IIIa inhibitors, but its mechanism has not been elucidated yet. With use of flow cytometry, the activation status of platelets was monitored in 26 patients presenting with acute myocardial infarction who were treated with the GP IIb/IIIa inhibitor abciximab alone or in combination with the fibrinolytic agent reteplase. Fibrinogen and PAC-1 (a GP IIb/IIIa activation-specific monoclonal antibody) binding, as well as P-selectin expression on unstimulated platelets were con..