[A case of chronic inflammatory demyelinating polyradiculoneuropathy concomitant with acquired von Willebrand syndrome].

We report a case of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) concomitant with acquired von Willebrand syndrome. A 33-year-old man developed motor and sensory polyneuropathy with electrophysiological conduction slowing. At this time, M-protein was absent He was diagnosed with CIDP and received intravenous immunoglobulin and subsequent oral corticosteroids, which resulted in almost complete remission for over 10 years. At the age of 44, he presented with chronic anemia. Laboratory tests and colonoscopy revealed that he had acquired von Willebrand syndrome with monoclonal gammopathy of undetermined significance (IgG lambda type) and colon cancer. Bleeding symptoms were.resolved with intravenous immunoglobulin, but not with supplementation of factor VIII. Shortly after successful excision of the cancer, CIDP and acquired von Willebrand syndrome simultaneously recurred. Intravenous immunoglobulin produced rapid improvement of both neurological and hematological abnormalities. Concurring CIDP and acquired von Willebrand syndrome in the present case may indicate that the conditions have a partly common immunological background including monoclonal gammopathy and a potential common autoantibody-mediated mechanism. Alternatively, dysfunction of von Willebrand factor may increase blood-nerve barrier permeability, inducing the recurrence of CIDP.