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) associated angiodysplasia and recurrent lower gastrointestinal bleeding is reported. Coagulation parameters at presentation were activated partial thromboplastin time of 41 sec, bleeding time >15 min, factor VIII procoagulant activity, 5%; von Willebrand factor antigen (WF:Ag) 5%, and vWF:ristocetirn cofactor activity 11% sodium dodecyl sulfate-agarose gel electrophoresis pattern of plasma vWF showed a pattern similar to type II vWD. An in vitro inhibitor against vWF in the immunoglobulin (Ig)G fraction of the patient's plasma was demonstrated vWF parameters showed a short-lived increase after 1-deamino-8-D-arginine vasopressin (DDAVP) administration. The patient's bleeding episodes were initially managed adequately with cryoprecipitate replacement therapy and DDAVP, to which she became refractory. No significant improvement was achieved following the institution of immunosuppressive therapy in the form of high-dose steroids and cyclophosphamide. She was then treated with intravenous immunoglobulin (IvIg) to which she showed an adequate response 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 association between idiopathic immune-mediated AvWD and angiodysplasia.