Platelet function and immunologic parameters in von Willebrand's disease following cryoprecipitate and factor VIII concentrate infusion.

Results of functional and immunologic tests of factor VIII and of platelet function were followed in two patients with severe von Willebrand's disease who were given cryoprecipitate during preparation for surgery. Initial correction of factor VIII coagulant activity was found to persist from 48 to 72 hours. Correction of immunologically measured factor VIII persisted for 48 hours and correlated with the patients' platelet response to ristocetin aggregation. Bleeding times were corrected for only 6 to 8 hours and showed fairly good correlation with the ristocetin aggregation factor, as suggested by Weiss. The administration of commercial factor VIII concentrate corrected all parameters except the bleeding time and the ristocetin aggregation factor measurement.