Chronic Active Epstein-Barr Virus Disease Causes Tubulointerstitial Nephritis and Growth Failure.

BACKGROUND: Chronic active Epstein-Barr virus (EBV) disease is a rare, potentially life-threatening condition characterized by the clonal proliferation of EBV-infected T or natural killer cells. Although it often manifests with systemic symptoms as seen with infectious mononucleosis, it rarely involves the kidneys or growth failure. CASE: A 9-year-old female patient presented with fever, malaise, anemia, kidney dysfunction and growth retardation. The initial diagnosis was acute tubulointerstitial nephritis based on a kidney biopsy, but further investigation, which included a polymerase chain reaction assay EBV, EBV-encoded small ribonucleic acid in situ hybridization and flow cytometry, detected EBV-infected CD4+ T cells in both kidney and bone marrow, which led to the diagnosis of chronic active EBV disease. Despite receiving chemotherapy, she experienced complications and died 3 months after the diagnosis. Her history was notable for recurrent pyogenic lymphadenitis at the age of 4 years, with a lymph node biopsy at that time remarkable for a positive EBV-encoded small ribonucleic acid in situ hybridization assay, thereby demonstrating the presence of a long-standing EBV infection. CONCLUSIONS: The present case emphasizes the need for early diagnosis of chronic active EBV disease using advanced diagnostic techniques, such as polymerase chain reaction and EBV-encoded small ribonucleic acid in situ hybridization, as well as recognition of atypical presentations such as growth failure and interstitial nephritis.