Platelet function in classic (AHF-deficiency) hemophilia: report of a case with defective platelet function.

C LASSIC HEMOPHILIA ( Hemophilia A) is a hereditary hemorrhagic disorder characterized by low to absent levels of anti-hemophiliac globulin ( AHF, Factor VIII ) . The bleeding time and other measurements of platelet function are usually described as normal. We have recently studied a patient with severe AHF-deficient hemophilia who has repeatedly developed a prolonged bleeding time and other signs of platelet dysfunction associated with a severe AHF inhibitor. Because of our interest in this patient, platelet function studies were performed on six other patients with classic hemophilia. In this paper the results of these studies are presented and the possible mechanisms involved in the defective platelet function seen in the original patient are discussed.