Idiopathic immune-mediated acquired von Willebrand's disease in a patient with angiodysplasia: Demonstration of an unusual inhibitor causing a functional defect and rapid clearance of von Willebrand factor

A case of idiopathic immune-mediated von Willebrand's disease (AvWD) associ ated angiodysplasia and recurrent lower gastrointestinal bleeding is report ed. Coagulation parameters at presentation were activated partial thrombopl astin time of 41 sec, bleeding time >15 min, factor VIII procoagulant activ ity, 5%; von Willebrand factor antigen (WF:Ag) 5%, and vWf:ristocetirn cofa ctor activity 11% sodium dodecyl sulfate-agarose gel electrophoresis patter n of plasma vWF showed a pattern similar to type II vWD. An in vitro inhibi tor against vWF in the immunoglobulin (Ig)G fraction of the patient's plasm a was demonstrated vWF parameters showed a short-lived increase after 1-dea mino-8-D-arginine vasopressin (DDAVP) administration. The patient's bleedin g episodes were initially managed adequately with cryoprecipitate replaceme nt therapy and DDAVP, to which she became refractory, No significant improv ement was achieved following the institution of immunosuppressive therapy i n the form of high-dose steroids and cyclophosphamide. She was then treated with intravenous immunoglobulin (IvIg) to which she showed an adequate res ponse in terms of her clinical situation and her hemostatic parameters. The patient is on maintenance treatment with repeated courses of IvIg based on vWF parameter monitoring, To our knowledge, this is the third reported ass ociation between idiopathic immune-mediated AvWD and angiodysplasia. (C) 19 99 Wiley-Liss, Inc.