Acquired factor V inhibitor treated with rituximab

Acquired factor V (FV) inhibitors are extremely rare and present with a broad spectrum ranging from asymptomatic laboratory anomalies to life-threatening critical bleeds. The overall rarity along with the heterogeneity of clinical presentations poses a challenge in diagnosis. There is currently no standard of care immunosuppressive therapy (IST) in these settings. Most patients in the literature receive multiple agents, including but not limited to combinations of IST and/or recombinant products.Here, we present a case of a man in his 50s who initially presented with oozing at peripheral IV and tracheostomy sites with intermittent epistaxis. He was later found to have an FV activity level of less than 1% and an FV inhibitor titre of 184 Bethesda units/mL. The patient was initially stabilised with fresh frozen plasma, platelets and tranexamic acid and treated with intravenous immunoglobulin and glucocorticoids. However, this resulted in only mild improvement in his coagulation studies. He was then treated with weekly doses of rituximab for 4 weeks with ongoing glucocorticoids without complications. This adds to the growing literature on rituximab as a possible treatment option for acquired FV inhibitors.