Postpartum acquired hemophilia A: immunopathogenesis, diagnostic challenges, and treatment with the CyDRi protocol

Acquired hemophilia A (AHA) is a rare, potentially life-threatening autoimmune bleeding disorder characterized by the development of inhibitory autoantibodies against factor VIII (FVIII). While most commonly diagnosed in the elderly, AHA can also occur in the postpartum period, where it presents unique diagnostic and therapeutic challenges. This review provides a comprehensive overview of the pathogenesis, clinical features, diagnostic approaches, and current therapeutic strategies for postpartum AHA. We highlight the immunological shifts during pregnancy and the postpartum period that may contribute to the breakdown of immune tolerance and the emergence of FVIII autoantibodies. Key aspects of laboratory diagnosis are outlined, including the role of coagulation screening, mixing studies, and inhibitor assays. We compare the efficacy and safety of established immunosuppressive regimens, with a particular focus on the CyDRi protocol-a combination of cyclophosphamide, dexamethasone, and rituximab-which has demonstrated high rates of complete remission with a favorable toxicity profile. To illustrate clinical application, we describe a case of severe postpartum AHA managed successfully with the CyDRi protocol, followed by an uneventful subsequent pregnancy. With timely diagnosis and appropriately tailored immunosuppressive therapy, postpartum AHA can be effectively treated, and favorable hematologic and reproductive outcomes are achievable.