Abstract
Acquired hemophilia is a life-threatening bleeding disorder by the development of autoantibody against factor VIII. The therapeutic approach relies on steroid, cyclophosphamide and/or cyclosporine. A 64-year-old man was referred to our hospital with extensive hematoma in both psoas muscles, severe anemia of 6.8 g/dl, prolonged activated partial thromboplastin time over 200 seconds, and factor VIII coagulation activity (FVIII: C) of 1.9%. A factor VIII inhibitor was detected at 118 Bethesda units (BU). The diagnosis of acquired hemophilia was made in the absence of a detectable cause. The inhibitor was IgG with a subclass of IgG4 and reacted with 72 kDa fragment of factor VIII light chain. Steroid pulse therapy following steroid treatment resulted in the resolution of acquired hemophila with marked and prolonged efficacy.
