Introduction: Acquired factor V inhibitor is rare and clinical symptoms are quite variable. Bleeding is the leading symptom but some patients are asymptomatic. Several diseases or conditions are associated with factor V inhibitors. Various treatments have been attempted but randomized or prospective trials are not available.
Exegesis: Here we report three cases of acquired factor V inhibitor. These reports highlight the clinical variability of this disorder. Pathogenesis and therapy with reference to the literature are discussed.
Conclusion: Factor V inhibitors are rare and associated to several diseases or conditions. Pathogenesis is still unclear except in patients exposed to bovine thrombin. The majority of the cases developed after surgery. In a few cases there is an association to a malignant or autoimmune disease. Plasmapheresis and platelet transfusions might be the best treatment in case of severe bleeding. High-dose intravenous immunoglobulin infusions have been used successfully in some cases and we report here their efficacy in two cases.