S5776 A Rare Case of Presumed Autoimmune Hepatitis Triggered by EBV: A Conservative Management Approach in the Absence of Liver Biopsy

Introduction: Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease marked by elevated transaminases, circulating autoantibodies, and interface hepatitis on histology. Epstein–Barr virus (EBV), a prevalent human herpesvirus, has been recognized as a potential trigger of various autoimmune conditions. Although EBV-induced AIH is rare, it is increasingly acknowledged as a possible etiologic factor. Most reported cases involve pediatric or immunocompromised patients, making presentations in immunocompetent adults particularly uncommon. This report presents a presumed case of EBV-associated AIH in a previously healthy middle-aged woman, highlighting the diagnostic and management challenges when liver biopsy is declined. Case Description/Methods: A 43-year-old woman presented with markedly elevated liver enzymes and jaundice. She had traveled to Mexico in late 2024 and subsequently developed altered bowel habits, fatigue, and progressive jaundice by early 2025. Initial laboratory tests revealed alanine aminotransferase (ALT) 1317 U/L, aspartate aminotransferase (AST) 1166 U/L, total bilirubin 9.7 mg/dL, and international normalized ratio 1.4. Viral hepatitis panel was negative for hepatitis A, B, and C viruses; however, EBV IgM antibodies and a positive Monospot test suggested a recent EBV infection. Autoimmune workup showed a smooth muscle antibody level of 31 and a positive antinuclear antibody. These findings were consistent with AIH. She denied alcohol use, recent medications or supplements, and had no family history of liver disease. Her liver enzymes improved spontaneously over the following 2 weeks (ALT 502 U/L, total bilirubin 8.6 mg/dL) and continued to improve over 2 months (ALT 91 U/L, AST 54 U/L, total bilirubin 2.5 mg/dL). She remained asymptomatic aside from jaundice and reported no abdominal pain. A computed tomography scan of the abdomen and pelvis showed heterogeneous liver enhancement and periportal edema. At 2 months, her albumin remained low at 3.3 g/dL, platelet count was 147 × 10⁹/L, and international normalized ratio had improved to 1.1. Discussion: This case highlights a rare instance of presumed EBV-triggered autoimmune hepatitis managed conservatively without histological confirmation. Positive autoimmune markers (SMA, ANA), persistent transaminase elevation over 2 months, and low albumin and platelets indicated autoimmune hepatitis likely triggered by EBV. It underscores the importance of recognizing EBV as a potential AIH trigger and the challenges in clinical decision-making when liver biopsy is declined, emphasizing careful monitoring and individualized patient care.