Acquired inhibitor of factor V: first report in China and literature review.

We reported a 51-year-old man who developed a severe haematuria with a prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT). Laboratory evaluation revealed the presence of specific factor V inhibitors. No underlying diseases and associated conditions have been identified. The patient improved after immunosuppressive therapy. However, the FV level remained low, indicating incomplete inhibitor eradication. The clinical course of our patient was consistent with the observations by others that FV inhibitor can be persistent for months or years.