OBJECTIVETo better understand the acquired factor V (FV) inhibitors.

METHODSThe clinical features, laboratory manifestations, treatment options and prognosis of 3 cases were reported and related literature were reviewed.

RESULTSAll the 3 patients were older than 50 years without family history and related disease. Their clinical manifestations included spontaneously mucous bleeding, hematuria, epistaxis and encephalic bleeding. Laboratory test showed prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT). The FV levels decreased and the presence of FV inhibitor was confirmed by Bethesda method. All patients were treated with glucocorticoid and immunosuppressive agents. The haemorrhages of two patients stopped but their coagulation test and FV level recovered slowly. One patient died from encephalic bleeding.

CONCLUSIONSAcquired FV inhibitor is a rare coagulation disorder with variable clinical symptoms. Immunosuppressive agents are effective to eliminate the inhibitors. The prognosis of acquired FV inhibitors seemed to be strictly related to the basic disease.