The von Willebrand Syndrome

Abstract

Five patients with an original diagnosis of von Willebrand''s disease are described because their levels of factor VIII related protein, ristocetin-induced platelet aggregation and/or family studies differed from the main group of patients with classical von Willebrand''s disease. Two had normal levels of factor VIII related protein with reduced ristocetin aggregation when this was tested in platelet rich plasma. In one patient this was due to a plasma defect and in the other to a platelet abnormality. After cryoprecipitate infusion all abnormal tests were corrected in both patients. The 1st patient failed to show a secondary rise of factor VIII but the 2nd showed a secondary rise of both factor VIII and factor VIII related protein. The other 3 cases, who were all severely affected, were separated from the main group as none of their families were segregating for classical von Willebrand''s disease. The term von Willebrand''s disease should be confined to patients who have reduced factor VIII related protein and ristocetin aggregation. Von Willebrand''s syndrome should be used for the various sub-groups that are emerging.