A case of acute-onset autoimmune hepatitis that showed false positive for IgM-HA antibody

Abstract

A 76-year-old woman was admitted to our hospital for general malaise and liver dysfunction. At first she was diagnosed as acute hepatitis A by laboratory findings, such as positive for IgM-HA antibody and clinical findings. Her liver dysfunction was temporary improved, however, it deteriorated again. She was treated with pulsed methylprednisolone and subsequent oral prednisolone (PSL). Liver dysfunction improved after the treatment, thus, PSL was discontinued. However liver dysfunction reappeared after 30 days from discontinuation of PSL. Her clinical and laboratory findings were fulfilled the criteria of autoimmune hepatitis. We finally diagnosed as acute onset autoimmune hepatitis because of low titer of IgM-HA antibody, negative of HAV-RNA and high titer of IgG-HA antibody. This is a suggestive case to diagnose early phase of autoimmune hepatitis.