Epstein-Barr Virus Gastritis

A 20-year-old Japanese woman with a 1-year history of ulcerative colitis presented with a fever, sore throat, diarrhea, and abdominal pain that persisted for 1 week. For 3 months prior to admission, she had received treatment with infliximab and undergone granulocytopheresis. One month prior to admission, the prednisone dose was tapered and was eventually discontinued. However, her abdominal symptoms worsened despite azathioprine maintenance therapy, which she continued to take until admission. Colonoscopy yielded unremarkable findings, but gastroscopy showed multiple ulcerative nodular lesions (Picture 1). Hematoxylin-Eosin staining of a biopsy specimen of the gastric mucosa showed lymphocyte infiltration (Picture 2). In situ hybridization for Epstein-Barr virus (EBV)-encoded RNA (Picture 3) revealed signals consistent with those observed for CD20-positive lymphocytes (Picture 4). The peripheral blood EBV load was 4,378 copies/μg DNA on admission; the EBV antibody titers were as follows: EBV capsid antigen (VCA) immunoglobulin G (IgG), 160; EBV-VCA IgM, <10; and EBV nuclear antigen (EBNA) IgG, <10. Therefore, we diagnosed