Introduction: Immunosuppressive therapy (IST) for acquired hemophilia A (AHA) results in remission within days to months in 60% to 80% of patients. However, little is known regarding the predictors of response.
Aim: This study aimed to identify the factors that influence response to treatment.
Methods: The data of 42 patients with AHA from three hospitals were retrospectively analyzed.
Results: All 42 AHA patients received IST; complete treatment data were available for 34 patients. The response rate was 60% among the 5/34 (14.7%) patients who received steroids alone, 70.8% among the 24/34 (70.6%) patients who received steroids plus cyclophosphamide, and 80% among the 5/34 (14.7%) patients who received steroids plus cyclophosphamide and rituximab. Overall, 29/34 (85.3%) patients achieved CR; 4/34 (13.8%) of them relapsed after a median time of 410 (21-1279) days. Adverse events occurred in 14/34 (41.2%) patients: 13/34 (38.2%) had infections and 1/34 (2.9%) developed pancytopenia. In univariate and multivariate Cox regression analyses, FVIII inhibitor titer ≥20 BU/mL was the only significant prognostic factor affecting time to CR. No variable had significant effect on OS.
Conclusion: FVIII inhibitory antibody titer ≥20 BU/mL appears to be an important predictor of time to complete response in patients with acquired hemophilia A treated with immunosuppressive therapy.
Keywords: acquired hemophilia; bypassing agents; factor VIII; immunosuppression; inhibitors; prognostic.