A case of autoimmune hepatitis exacerbated by the administration of etanercept in the patient with rheumatoid arthritis

A 50-year-old woman was admitted for active rheumatoid arthritis (RA). She was found to have RA 1 year prior to this admission. Past history was unremarkable and she had no family history for rheumatic diseases. As nonsteroidal anti-inflammatory drug (NSAID) and methotrexate were not effective, etanercept was started (25 mg, twice a week). Mild elevation of alanine transaminase (ALT) and aspartate transaminase (AST) was found as an outpatient, and it was considered to be NSAID-induced liver injury. Two weeks after the first dose of etanercept, she developed progressive elevation of AST and ALT with right upper quadrant tenderness and hepatomegaly. Etanercept was discontinued and liver biopsy was performed, which demonstrated portal-area-dominant lymphoplasmacytic inflammatory cell infiltration. She was diagnosed as autoimmune hepatitis (AIH). Glucocorticoid was started with normalized liver function and stable joint symptoms. AIH was thought to be acutely aggravated by the administration of etanercept.