Abstract
Background: In December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified and has subsequently been responsible for immense morbidity and mortality. This resulted in the development of vaccines in record time, potentially posing safety issues. Several cases of acquired hemophilia A (AHA) following coronavirus disease 2019 (COVID-19) vaccines have been described in the literature. AHA is a rare autoimmune disease due to the production of IgG autoantibodies to coagulation FVIII that burdens high morbidity and mortality. It is presumed mainly on identifying an increased activated partial thromboplastin time (aPTT), even without bleeding and is confirmed by determining a FVIII inhibitor. To the best of our knowledge, this is the first report of AHA after inactivated virus COVID-19 treated with low dose rituximab (RTX). Lower RTX doses may lead to shorter infusion duration, lower risk of adverse events and lower costs. Case presentation: We report a case of AHA occurring in a 69-year-old man 60 days after an inactivated Sinovac-coronavac COVID-19 vaccine. Diagnosis of AHA was based on clinical presentation and confirmed with prolonged activated partial thromboplastin time, Factor VIII deficiency and the presence of an FVIII inhibitor. Follow-up showed a significant clinical and biological improvement, aPTT was normalized as of 18 days of treatment with corticosteroids along with low dose rituximab. Conclusions: In the literature, the reported cases of AHA following COVID-19 vaccination occurred after Adenoviral Vector DNA- and SARS-CoV-2 mRNA-based COVID-19 vaccines. Here, AHA was presented following inactivated virus COVID-19 vaccine. AHA treated with low dose rituximab can limit occurrence of side effects and the cost of treatment.