[Acquired hemophilia A associated with bullous pemphigoid and multiple myeloma: a case report]

Acquired hemophilia A (AHA) is a rare and potentially severe bleeding disorder caused by circulating autoantibodies directed against factor (F) VIII. Apart from idiopathic cases, AHA is associated with autoimmune diseases, cancers, use of medications, pregnancy and the post-partum period. We report the case of a 78-year-old a male patient presenting with symptoms of a hematoma after a fall three days previously. He is medically followed for multiple myeloma and bullous pemphigoid. Laboratory investigations revealed isolated and recent increased of activated partial thromboplastin time (80,6/32,1s) and a markedly low FVIII activity (< 1%). The high-titer of FVIII inhibitor (19 Bethesda units/mL) confirmed the diagnosis of AHA diagnosis. The symptoms were noticeably alleviated following bortezomib, cyclophosphamide and dexamethasone therapy. This report describes a rare case of AHA associated with bullous pemphigoid and multiple myeloma. These pathologies induce an immunity modification that can predispose or be associated with the development of anti-FVIII inhibitors. This case illustrates two possible physiopathological hypotheses for the development of AHA, which will be discussed in this case report.