THROMBOCYTOPENIA CORRECTED BY WARFARIN IN ANTIPHOSPHOLIPID SYNDROME

We describe a case of antiphospholipid associated thrombocytopenia in which warfarin, but not heparin, normalized the platelet count. System ic lupus erythematosus was present in association with chorea, mitral valve stenosis, and renal thrombotic microangiopathy. No evidence of p latelet consumption was detected. Low dose aspirin, pulse methylpredni solone, intravenous gammaglobulin, and cyclophosphamide also partially elevated the platelet count. Platelet activation, measured by P selec tin assay, was not present during warfarin or aspirin therapy, suggest ing that platelet activation may have been decreased by these treatmen ts. We discuss possible mechanisms for correction of thrombocytopenia in antiphospholipid syndrome by warfarin.