Acquired Hemophilia-A Case Series and Review

Abstract

Background: Acquired hemophilia A (AHA) is a rare, life-threatening autoimmune disorder characterized by inhibitory autoantibodies against factor VIII (FVIII), resulting in spontaneous or trauma-related bleeding. This study reviews a single-center cohort to evaluate patient characteristics, treatments, and outcomes. Methods: We retrospectively reviewed the records of 22 adult patients diagnosed with AHA between 2012 and 2024. The data included demographics, clinical presentation, laboratory findings, treatments, and outcomes. Statistical analysis compared genders and evaluated treatment strategies and remission outcomes. Results: The cohort had an equal gender distribution with an average age of 62 years (22-102 years). Suspected etiologies included pregnancy (27%), malignancy (23%), autoimmune diseases (5%), and idiopathic causes (45%). The most common presentation was spontaneous cutaneous hematoma (82%). Severe bleeding necessitating hemostatic therapy occurred in 9% of cases. Initial immunosuppressive therapy (IST) with corticosteroids achieved remission in 45% of patients, while additional treatment with Rituximab or Cyclophosphamide was required in others. Emicizumab, a novel FVIII-mimetic, was successfully used in one patient with severe refractory bleeding. Remission was achieved in 64% of patients within a median of 3 months, with a recurrence rate of 14%. No thrombotic events were observed, although corticosteroid side effects, including one hip fracture, were noted. Conclusions: IST remains the cornerstone of AHA treatment, though side effects necessitate individualized care. Emicizumab shows promise, particularly in refractory cases and fragile populations. Future research is needed to evaluate long-term outcomes and spontaneous remission rates, especially in special populations like post-partum women and the elderly.

Keywords: Emicizumab; Rituximab; acquired bleeding disorder; acquired hemophilia; pregnancy-induced acquired hemophilia.

Figure 1

(A) Prothrombin time (PTT) in seconds over time (months) from diagnosis in male and female patients with acquired hemophilia A. Initial PTT levels were elevated in both genders, with a progressive decrease observed during follow-up, reaching comparable levels by six months post-diagnosis. (B) Average factor VIII levels (%) over time (months) from diagnosis in male and female patients with acquired hemophilia A. Both genders showed progressive increases in factor VIII levels during follow-up, with males demonstrating slightly higher levels by six months. (C) Average factor VIII inhibitor levels (%) over time (months) from diagnosis in male and female patients with acquired hemophilia A. Both genders showed progressive decrease in factor VIII inhibitor levels during follow-up period.

Figure 2

Time to AHA remission. Most patients (10/14) with remission achieved it in a period of up to 6 months from diagnosis.