Chronic Active Epstein?Barr Virus Infection Indistinguishable from Autoimmune Hepatitis: A Case Report

Chronic active Epstein–Barr virus (CAEBV) infection is a rare disease, mainly affecting children, typically characterized by persistent infectious mononucleosis (IM)-like symptoms. We describe an adult case of CAEBV without IM-like symptoms, which was indistinguishable from autoimmune hepatitis (AIH). A 60-year-old woman with liver damage was diagnosed with AIH (International Diagnostic Score: 16 points). She had been treated with prednisolone for three years; however, her transaminases had never normalized. She was admitted for another liver biopsy due to repeated high fevers and worsening of her liver damage over two months. Her EBV-DNA copy number was 2.9 × 10(4) copies/μg DNA, and EBV-encoded small RNA1-positive lymphocytic infiltration was observed in both the present and previously collected (three years ago) liver tissue samples. This case implies that hepatic involvement in a CAEBV without IM-like symptoms is difficult to distinguish from AIH and may be misdiagnosed. In some steroid resistant AIH cases, evaluating for CAEBV may be valuable.