Abstract

A patient with acquired von Willebrand disease and gastrointestinal telangiectasia is described. He presented with the recent onset of spontaneous hemorrhage and demonstrated a prolonged bleeding time, reduced factor VIII coagulant (FVIII:C), and undetectable factor VIII-related antigen (FVIIIR:AG) and ristocetin cofactor (FVIIIR:WF). Following transfusion of cryoprecipitate, there was a smaller than expected immediate increase in FVIII:C, FVIIIR:WF and FVIIIR:AG, with a rapid return to baseline levels and no secondary increase in FVIII:C. An inhibitor could be demonstrated in the patient's plasma which markedly decreased the level of FVIIIR:AG in normal plasma whereas it only weakly decreased the activity of FVIIIR:WF and FVIII:C. The inhibitor was contained in the immunoglobulin G(IgG) fraction of plasma and lacked precipitating properties. This inhibitor demonstrates a specificity not previously seen in spontaneous antifactor VIII antibodies. Our report also demonstrates that ristocetin-induced agglutination of platelets is not always the most sensitive method for detecting an inhibitor in acquired von Willebrand disease.