When Catastrophic Antiphospholipid Syndrome Meets Acquired Haemophilia A ; A Diagnostic and Management Challenge in Newly Diagnosed Systemic Lupus Erythematosus

Background : Catastrophic antiphospholipid syndrome (CAPS) and acquired haemophilia A (AHA) are both rare, life-threatening complications that require immediate medical intervention. CAPS is a severe manifestation of antiphospholipid syndrome (APLS), characterized by widespread thrombosis that can affect multiple organs, leading to high morbidity and mortality. AHA, on the other hand, involves autoantibodies that inhibit plasma coagulation factors, particularly factor VIII (FVIII), resulting in a bleeding tendency. Clinical case: We presented a 30-year-old man with coexistence of CAPS and AHA as the initial presentation of systemic lupus erythematosus (SLE), an autoimmune disorder. The patient had typical SLE symptoms such as oral ulcers and alopecia, alongside evidence of active disease with low complement levels (C3, C4), positive antinuclear antibodies (ANA), and anti-double-stranded DNA antibodies. The diagnosis of CAPS in this patient was supported by thrombotic events involving the skin, liver, and spleen, along with positive lupus anticoagulant (LA). The presence of low FVIII levels from the mixing test led to the diagnosis of acquired haemophilia A. This dual diagnosis posed a unique clinical challenge, as CAPS requires prompt anticoagulation while AHA predisposes to significant bleeding. The patient received aggressive treatment with intravenous methylprednisolone, plasma exchange, intravenous immunoglobulin (IVIG), and intravenous cyclophosphamide, leading to a favourable outcome. Follow-up testing after two weeks showed that the autoantibodies were successfully eradicated, and there were no detectable inhibitors of factor VIII. Clinical conclusion; This case highlights the importance of early recognition and prompt intervention in managing the coexistence of CAPS and AHA in SLE patients. The rapid initiation of immunosuppressive therapy, along with plasma exchange and IVIG, was critical in preventing further complications. Delayed treatment in such cases is associated with poor outcomes, underscoring the need for a multidisciplinary approach in managing these complex autoimmune conditions.