Acquired hemophilia A in the setting of dual anticoagulation therapy and lupus anticoagulant: a case report.

Background: Acquired hemophilia A is a disorder caused by autoantibodies against coagulation factor VIII that may present with severe bleeding. We report a rare case of acquired hemophilia A presenting with coexisting lupus anticoagulant.

Case Presentation: An 81-year-old Caucasian female presented with large ecchymoses over the torso and extremities in the setting of an enoxaparin bridge to warfarin. Anticoagulation was held, but she continued to develop bruises with significant anemia and prolonged coagulation studies that failed to correct with mixing. Workup revealed factor VIII activity < 1% and a positive lupus anticoagulant. Initial testing for a factor VIII inhibitor was confounded by the presence of lupus anticoagulant, requiring a chromogenic Bethesda assay to confirm the presence of the inhibitor, establishing the diagnosis of acquired hemophilia A. The patient was initially treated with oral prednisone 80 mg daily and factor VIII inhibitor bypassing activity 25 units/kg twice daily before transitioning to susoctocog alfa 50 units/kg twice daily after placement of a tunneled line for outpatient rituximab infusions. On discharge, the patient's ecchymoses were resolving and factor VIII levels improved. Following completion of rituximab therapy, the patient's factor VIII activity normalized and factor VIII inhibitor was suppressed.

Conclusions: Diagnosis of acquired hemophilia A can be confounded by other causes of abnormal coagulation studies and may require specialized testing, such as a chromogenic Bethesda assay, to confirm the presence of a factor VIII inhibitor.