Acquired factor V inhibitor complicated by Hashimoto's thyroditis, primary biliary cirrhosis and membranous nephropathy.

A 59-year-old man diagnosed as having Hashimoto's thyroditis, primary biliary cirrhosis (PBC) and membranous nephropathy (MN) showed consciousness disturbance, convulsions of the upper part of his body, and rapid progression of anemia, which seemed to be derived from subdural and retroperitoneal hemorrhage, respectively. He had been diagnosed as having eosinophilia about 6 weeks before the attack. Coagulation tests revealed a prolonged activated partial thromboplastin time and prothrombin time, which could not be normalized by mixing with normal plasma. Factor V (FV) activity was severely decreased and the purified immunoglobulin G of the patient inhibited normal plasma FV activity in a dose-dependent manner, suggesting the presence of antibody-mediated circulating inhibitors specific for FV. Treatment with steroids and azathioprine as well as plasmapheresis led to improvement of his clinical symptoms, normalization of the coagulation tests, and disappearance of eosinophilia. However, the inhibitor reappeared about 7 months later in association with eosinophilia, which was also improved by steroid therapy. To our knowledge, this is the first report of the co-existence of these three kinds of immune-mediated disorders, and the first report concerning the association between acquired FV inhibitors and PBC with MN. A new unknown immune mechanism, which causes eosinophilia, may be involved in the development of the FV inhibitor in this patient.