Characteristics and outcome of a territory-wide cohort study of patients with acquired hemophilia A in Hong Kong

Abstract

<h3>Introduction</h3><p>Acquired hemophilia A (AHA) is a rare bleeding disorder with destruction of factor VIII by autoantibodies. Comprehensive data for Chinese patients are lacking. Predictors of hospital stay have not been investigated.</p><h3>Methods</h3><p>A territory-wide review of patients diagnosed with AHA from January 1, 2012, to December 31, 2021 was performed by retrieving patients' information from an electronic database system in Hong Kong.</p><h3>Results</h3><p>Overall, 165 patients were included in this 10-year study, and the estimated incidence was 2.4 per million/year, which was higher than those reported from Caucasian cohorts. The median age of diagnosis was 80 years old. Patients had a long hospital stay (median: 25 days) and high mortality (55.2 %). The majority of deaths were caused by immunosuppression-related sepsis (49.5 %). Age was an independent predictor of overall survival (Hazard ratio: 1.065, 95 % CI: 1.037–1.093, <em>p</em> < 0.001), complete remission (CR) status (odd ratios (OR): 0.948, 95 % CI: 0.921–0.976, p < 0.001) and time to achieve CR (OR: 1.043, 95 % CI: 1.019–1.067, p < 0.001). Higher hemoglobin level on presentation was associated with shorter time to achieve CR (OR: 0.888, 95 % CI: 0.795–0.993, <em>p</em> = 0.037). Factor VIII level < 1 % normal, high inhibitor titer and intensive immunosuppressive regimen predicted long hospital stay.</p><h3>Conclusion</h3><p>We presented comprehensive data of Chinese patients with AHA which comprised predominantly frail elderly who required long hospital stay and had high sepsis-related mortality. This posed challenges in managing AHA in such patients. Individualized immunosuppressive therapy is needed to balance the benefits and risk of septic complications.</p>