Epstein-Barr virus genome-positive tubulointerstitial nephritis associated with immune complex-mediated glomerulonephritis in chronic active EB virus infection.

Renal involvement is rare in chronic active Epstein-Barr (EB) virus infection. We report a case of a 7-year-old girl with recurrent EB virus infection. She had fever, lymphadenopathy, hepatosplenomegaly, and persistently high titres of IgG to EB virus capsid antigen (VCA) and IgG to EB early antigen with low titres of IgM to VCA. She showed mild haematuria and proteinuria, but had no symptoms of renal failure. Renal biopsy revealed immune complex-mediated glomerulonephritis, which may have been due to a persistently high titre of antibody against EB virus. In addition, a peculiar form of tubulointerstitial nephritis was found. The morphology was characterized by a papillary infolding of the tubular epithelial cell layer into the tubular lumen. The interstitium was surrounded by the infolded epithelium and contained a large number of B-cell dominant lymphocytes. EBV-encoded RNA 1 (EBER-1) gene was detected in the nuclei of some tubuloepithelial cells by in situ hybridization and may have been associated with the pathogenesis of tubulointerstitial nephritis.