Epstein-Barr virus infection of renal proximal tubule cells: possible rolein chronic interstitial nephritis

Chronic interstitial nephritis frequently accompanies renal diseases of dif ferent etiologies. Far less common is the entity of primary interstitial ne phritis wherein the glomerular and vascular structures of the kidney are no t the primary focus of the disease process. Using in situ hybridization and the polymerase chain reaction, we detected DNA from the Epstein-Barr Virus (EBV) exclusively in renal tissue of patients with the idiopathic variety of chronic interstitial nephritis. The EBV genome, but not that of cytomega lovirus or adenovirus, was detected primarily in renal proximal tubule cell s. Furthermore, the CD21 antigen, which serves as the receptor for EBV in B lymphocytes, was detected by immunocytochemistry primarily on proximal tub ule cells and was markedly upregulated in the EBV-infected tissue. Western blot analysis of primary cultures of normal proximal tubule cells identifie d a 140-kDa protein, confirming the expression of the CD21 antigen. Colocal ization experiments using proximal and distal tubule markers confirmed that EBV DNA and the CD21 antigen are found primarily in proximal tubule cells. EBV infection of renal proximal tubular cells may participate in evoking a cellular immune response that results in a damaged renal, interstitium.