PO0029 - Acquired Hemophilia A: case report

Background: Acquired hemophilia A (AHA) is a rare but clinically significant bleeding disorder resulting from circulating autoantibodies that target and inhibit coagulation factor VIII (FVIII). It is well-established that underlying condition such as autoimmune diseases, malignancies and post-partum status have a clear association with AHA. However, about half of the cases are considered idiopathic.

Aims: We describe the case of a 40-year-old Caucasian woman diagnosed with AHA with a possible autoimmune disease as an underlying cause.

Methods: Collected data was obtained from patient record.

Results: The patient was being followed recently by our Rheumatology department due to polyarthralgia. The initial coagulation assessment revealed a prolonged activated partial thromboplastin time (aPTT) with a normal prothrombin time, which was initially explained by the presence of a lupus anticoagulant. However, a positive history for spontaneous and prolonged bleeds in the previous year, namely multiple unexplained ecchymosis and several episodes of gross hematuria, prompted the study of a possible bleeding disorder. The aPTT mixing study failed to correct the prolonged aPTT. The intrinsic pathway coagulation factors activities were measured and FVIII activity was 4%. We tested for the presence of a FVIII inhibitor using the Bethesda assay, which determined a titer of 7.90 Bethesda Units. The diagnosis of AHA was then established. Our patient initiated treatment with prednisolone 1 mg/Kg daily PO. After 3 weeks, FVIII activity was normal and inhibitor testing was negative. Furthermore, bleeding symptoms had ceased and corticosteroid tapering was begun. Our patient remains in monthly follow-up.

Conclusion(s): The onset of bleeding symptoms should grant a laboratory investigation with an assessment of routine coagulation assays. An isolated prolonged aPTT should cause caution about this diagnosis. Bleeding can be often severe. Fast diagnosis is critical, as well as early strategies to bleeding control. Inhibitor eradication with immunosuppressive agent is the cornerstone of AHA treatment.