[Acquired hemophilia A treated with rituximab. Report of one case]

We report a 54-year-old male presenting with a history or recurrent nose bleeds and ecchymoses. The coagulation study showed a prolonged partial thromboplastin time, a factor VIII of 8% and a high inhibitor titer (193 Bethesda units). A diagnosis of acquired hemophilia A was reached. The patient was initially treated with cyclophosphamide for seven months without response. Therefore rituximab in doses of 375 mglm²/week for four weeks was started. After starting treatment, the patient had a hematoma in the psoas muscle with a concomitant factor VIII of less than 5%, that was treated with local measures. Thereafter, a progressive reduction in inhibitor titers was observed, until its disappearance at five months of treatment. Factor VIII levels normalized and the patient has not experienced abnormal bleeding episodes. The patient remains in remission after 67 months of follow up. Rituximab, a chimeric monoclonal antibody against the protein CD 20 is an effective treatment in acquired hemophilia A.