Hepatitis E virus (HEV) infection is an emerging health concern in developing and developed countries, such as Japan. Five cases have recently been diagnosed as hepatitis E. Of interest, 3 of them had rheumatoid arthritis (RA), although a previous study demonstrated a lack of association between HEV and RA. One of the other patients developed autoimmune hepatitis and was successfully treated with corticosteroids approximately 150 days after the diagnosis of hepatitis E. In RA patients with liver dysfunction, the presence of HEV infection should be evaluated immediately because these patients are often relatively old. Further investigation of the association between HEV and autoimmune hepatitis is needed.
Keywords: Autoimmune hepatitis; Hepatitis E virus; IgA anti-hepatitis E virus antibody; Rheumatoid arthritis.