An Unusual Association Between Acquired Hemophilia A and Type 2 Autoimmune Pancreatitis

Acquired hemophilia A (AHA) is a rare autoimmune bleeding disorder that can be triggered by underlying immune-mediated diseases. We report the case of a 63-year-old man who developed AHA 1 month after undergoing pancreaticoduodenectomy for a pseudotumoral lesion, which was histologically consistent with type 2 autoimmune pancreatitis (AIP). The patient presented with gastrointestinal bleeding, a markedly prolonged activated partial thromboplastin time, reduced factor VIII (FVIII) activity (3%), and a detectable FVIII inhibitor (1.4 Bethesda units/mL). Treatment with recombinant porcine FVIII and oral corticosteroids led to rapid control of bleeding, progressive inhibitor eradication, and complete remission, that has been maintained for 3 years. This case broadens the spectrum of autoimmune conditions associated with AHA and represents, to our knowledge, the first reported instance of AHA occurring in association with type 2 AIP.