A Circulating Anticoagulant Directed against Antihaemophilic Globulin (Factor VIII) Combined with Thrombocytopenia

Abstract

SummaryA circulating anticoagulant directed against factor VIII (antihaemophilic globulin) is described which developed in association with thrombocytopenia in an otherwise apparently healthy woman. Inactivation of factor VIII by this inhibitor was shown to be progressive and temperature dependent. The circulating anticoagulant was not species specific and produced temporary factor VIII deficiency when injected into dogs. Administration of large doses of corticosteroids to the patient did not affect the factor VIII inhibitor and resulted only in a temporary increase in the platelet counts. In the course of subsequent immunosuppressive treatment with azathioprine, the inhibitor disappeared and clinical symptoms improved, whereas thrombocytopenia persisted.