Single centre experience on Acquired Haemophilia A patients: Diagnosis, clinical management and analysis of factors predictive of response and outcome

Background: Acquired Haemophilia A (AHA) patients show a high response rate to immunosuppressive therapy (IST) but few information about predictors of response and outcome are reported. Aims: We describe a large single-centre AHA cohort, investigating prognostic variables for the ‘best response’ (BR), time to BR (TTBR) and overall survival (OS). Methods: A total of 61 patients were included, collecting data from clinical charts. Results: A progressive increase in diagnoses, from 1978 to 2019, was observed. Fifty/56 patients (89%) underwent haemostatic therapy (rFVIIa 46%, aPCC 34%) with no significant differences in the response (rFVIIa 92.3% vs aPCC 100%) and no thromboembolic events. Sixty/61 patients underwent first-line IST with an initial response rate of 58.4%. The 12-months OS was 85%, the bleeding associated mortality rate 3% (2/61). The response rates at last observation were: CR 64%, PR 8%. We evaluated the influence of age, gender, associated conditions, IST, haemoglobin levels, FVIII:C, inhibitor titre on BR, TTBR and OS: post-partum AHA achieved the BR after a longer time than AHA related to other aetiologies or idiopathic (p =.05); in univariate analysis female sex (p =.03) and the achievement of BR (p =.001) had a positive impact on the OS while AHA secondary to neoplasms showed a shorter survival (p =.04); only the BR achievement remained significant in multivariate analysis (p =.02). Conclusions: Our data on response and survival confirmed those from the main registries. Post-partum AHA and BR achievement were significantly associated to a longer TTBR and a longer OS, respectively. Other predictors of outcome deserve to be explored in prospective studies.