[Elderly patient with acquired hemophilia A with IX・XI and XII factor decline].

Acquired hemophilia is a rare bleeding diathesis caused by autoantibodies against clotting factor VIII. Many cases are associated with autoimmune disease, malignancy and an elderly status. Acquired hemophilia is very rare, with a reported annual incidence of 1.48/million/y. However, it is necessary to consider this rare disease when encountering bleeding of unknown cause in elderly patients. An 84-year-old woman was referred to our hospital with subcutaneous bleeding and anemia. The patient had severe anemia and a prolonged activated partial prothrombin time (APTT). Despite the administration of red blood cell transfusions, the decline in hemoglobin continued. Since the activity of coagulation factor VIII was <1%, and the level of inhibitor against coagulation factor VIII (509 BU/ml) was >5 BU/ml, the patient was diagnosed with acquired hemophilia. No underlying diseases were found, and we concluded that this case was idiopathic. Although she was treated with prednisolone at a dose of 40 mg per day, the bleeding tendency did not improve. Therefore, she was given activated prothrombin complex concentrates (APCC) for four days. The subcutaneous bleeding and Hb decline stopped, and the dose of prednisolone was gradually reduced. The patient's clotting function and clinical course were satisfactory, and she was discharged on the 64th day. An early diagnosis and optimal treatment are critical for treating acquired hemophilia. The development of a bleeding tendency related to the appearance of coagulation factor VIII inhibitor is serious in many patients. Therefore, recognizing this disease and providing prompt management are necessary.