CT-157 Another Rare Case of COVID-19 Vaccine Induced Acquired Hemophilia

Context: Acquired hemophilia A is an autoimmune bleeding disorder that results from autoantibodies against coagulation factor VIII. Failure to recognize AHA as a cause of bleeding results in delayed management. Objective: Case report of acquired hemophilia after receiving COVID-19 vaccines (Pfizer-BioNTech SARS-CoV-2 mRNA vaccine). Design and Patient Criteria: A case report of a lady who attended the haematology clinic at the University College London hospital. This included history taking, physical examination, full blood count, coagulation screen and factor assay, factor VIII inhibitor assay, immune workup, and CT scan. Main Outcome: We reported this 40-year-old lady with no previous medical history. She presented with massive vaginal bleeding and anemia which needed a blood transfusion. This coincided with her first dose of the Pfizer vaccine. Investigations showed high APTT at 45 sec, Factor VIII level at 0.3 IU/ml, Factor VIII Bethesda antibodies assay at 0.8 with normal other coagulation work up. Immune profile (ANA, Anti-dsDNA, C3, C4, and lupus workup) was negative and CT whole body showed no abnormalities. She was started on prednisolone 60 mg after which her bleeding improved and factor VIII level increased to 0.5 IU/ml. Once she started steroid withdrawal bleeding re-occurred and factor VIII level dropped to 0.21 IU/mL with APTT prolongation to 45 sec. Subsequently, she received 4 weeks of rituximab resulting in Factor VIII level normalization at 1.51 IU/ml, normal clotting screen and resolution of bleeding which has been sustained since November 2021. Conclusions: While thrombosis is a side effect of COVID-19 infection, bleeding can still happen in the setting of COVID-19 infection/vaccination. Till recently, only a few cases of acquired hemophilia have been reported after receiving mRNA-derived COVID-19 vaccines. Related Haematologic autoimmune disease may involve stimulation of auto-antibody production from preexisting B cells by triggering autoimmunity. It is crucial to raise awareness about this side effect that may be directly induced by the mRNA COVID-19 vaccine. We highly recommend screening for an antibody inhibitor with unexplained bleeding and/or isolated activated partial thromboplastin time prolongation following the COVID vaccine.