A Case with Severe Bleeding Caused by the Acquired Factor VIII Inhibitor

An 81-year-old woman with no history of coagulation disorder was admitted due to swelling and pain in the right thigh. Computed tomography (CT) and magnetic resonance imaging (MRI) showed hemorrhaging in the muscles of the right thigh. Abdominal CT during hospitalization retroperitoneal bleeding. Laboratory examination revealed rapidly progressive anemia, prolonged activated partial thromboplastin time (aPTT), markedly decreased factor VIII activity, and positive factor VIII inhibitor titer. She was diagnosed with coagulopathy due to spontaneously acquired factor VIII inhibitor. Her bleeding did not respond to the infusion of factor VIII concentrate, but was successfully treated by activated prothrombin complex concentrate (aPCC) and PCC. To reduce the production of factor VIII inhibitor, an immunosuppressive regimen, including prednisone and cyclophosphamide, was started. Inhibitor titer gradually decreased and no further bleeding occurred, but the patient died of sepsis caused by a nosocomial airway and urinary tract infection. This suggests that the dose of immunosuppressive drugs should be lower than in the ordinary regimen in such elderly patients.