A Case of Autoimmune Hepatitis Complicated by Undiagnosed Factor VII Deficiency: A Pitfall of Coagulopathy.

Prothrombin time (PT) is a key parameter for assessing the severity of liver disease. We present the case of a 37-year-old woman with severe acute liver injury due to autoimmune hepatitis. Although prednisolone drastically improved her hepatocyte function, her PT did not recover to the reference range. A review of her medical records revealed that the patient had normal transaminase levels and prolonged PT 2 years previously. Further examinations of her coagulopathy revealed that she had low factor VII activity, suggesting a diagnosis of factor VII deficiency. Our experience suggests that altered coagulopathy should be considered in cases of liver injury with an extraordinary PT.