Evaluation of Qualitative Platelet Disorders in Patients with Hemophilia.

The hemophilias are inherited disorders of the coagulation system with no apparent effects on primary hemostasis. However, bleeding times and platelet aggregation have been reported as abnormal. These observations have been ascribed to undiagnosed Von Willebrand’s Disease (VWD), effects of factor replacement, or drugs. We evaluated three patients with hemophilia including one patient with factor VIII deficiency, one with factor VIII and inhibitor, and one factor IX who had persistent bleeding despite their standard treatment. Initial evaluation of primary hemostasis demonstrated abnormal bleeding time and or platelet function analysis (PFA-100). VWD antigen and ristocetin cofactor were normal. Electron microscopy demonstrated alpha and or delta granule storage pool deficiency. Careful review of all drugs the patients were on did not explain this finding. Repeat evaluation of one patient over time demonstrated persistence of abnormal function. Treatment with DDAVP(Desmopressin) normalized in vitro function in 2 patients. After documentation of these abnormalities, two patients were treated with DDAVP with or without platelets as well as factor replacement or in face of inhibitors FEIBA or FVIIa. Clinical improvement was seen in the 2 patients after this intervention. A prospective study of our hemophilia population has been initiated with the goal of documenting the frequency of storage pool deficiency, the importance of the disorder to bleeding episodes and treatment response, and to determine whether this is inherited or acquired.