A Prolonged Treatment Response in Acquired Von Willebrand Syndrome.

Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder. We report herein a case of AVWS due to a monoclonal gammopathy of undetermined significance, in which a transient but prolonged response to a treatment by intravenous immunoglobulin (IVIG) was observed. The diagnosis was fortuitously made in a preoperative setting for neurosurgery, after biological exploration of an isolated prolonged activated partial thromboplastin time. AVWS was confirmed by an accelerated clearance of an infused plasma-derived von Willebrand factor (VWF) concentrate. High doses of IVIG were used to perform the neurosurgery. Fifty-four days after IVIG, the patient was still responding to treatment with normal levels of factor VIII and VWF.