To evaluate the long‐term effects of anti‐tumor necrosis factor‐alpha (TNF‐α) therapy on patients with chronic hepatitis B and C infections.

Rheumatoid arthritis, ankylosing spondylitis and Crohn's disease patients administered anti‐TNF‐α therapy for at least 36 months were retrospectively reviewed for hepatitis B or C serology, liver function tests, viral load, genotype and liver biopsy results, if performed. Nine relevant cases receiving anti‐TNF‐α were evaluated: six patients had chronic hepatitis C, one had chronic dual hepatitis B and C and two had chronic hepatitis B infection.

The patient with dual infection exhibited virologic breakthrough for hepatitis C and required treatment. Two patients with occult hepatitis B infection developed hepatitis B surface antigen (HBsAg) reversion and low‐level viremia at the end of the study.

Long‐term use of anti‐TNF‐α treatments may result in viral replication that requires anti‐viral therapy. Before determining the safety of anti‐TNF drugs in the treatment of autoimmune diseases in patients with hepatitis C infection, studies with large homogeneous patient groups must be performed, and the exact group of hepatitis C virus infected patients for whom anti‐TNF treatment would be deemed safe should be identified. Prior to anti‐TNF‐α treatment, it seems logical to screen all patients for HBsAg and anti‐HB core immunoglobulin G status, especially in endemic regions. These patients must be followed periodically by means of alanine aminotransferase, HBsAg and hepatitis B virus DNA to identify HBsAg reversion and active viral replication that might require anti‐viral prophylaxis or treatment.