Platelets and Factor VIII in von Willebrand's Disease

To the Editor: In his excellent review, Jaffe¹ asks, “What happens to the factor VIII antigen content of the two platelet pools when patients with von Willebrand's disease of severe degree are given transfusions of plasma factor VIII?” We have performed in vitro and in vivo studies to answer his question. Immunofluorescent staining of platelets of patients with von Willebrand's disease incubated with normal plasma indicated that factor VIII antigen did not become platelet bound unless aggregation was induced by ristocetin.² Likewise, platelets obtained from such patients after cryoprecipitate infusion showed minimal or no staining before but intense staining. No extract is available for articles shorter than 400 words.