Systemic Epstein-Barr virus infection associated with membranous nephropathy in children.

Epstein-Barr virus (EBV) infection can cause diverse renal manifestations ranging from microscopic hematuria to acute renal failure. Membranous nephropathy (MN) is an uncommon and usually secondary cause of nephrotic syndrome in children, and has been reported after chronic infections and antigenemia. We report two pediatric cases of secondary MN associated with acute and chronic systemic EBV infection. Patient 1 had a liver transplant for cirrhosis due to biliary atresia and developed chronic EB viremia. Membranous nephropathy occurred 3 years later and with aggressive therapy has partially subsided, in temporal association with a drop in blood EBV PCR levels. The other patient had a primary immunodeficiency and developed a lymphoproliferative disorder attributed to EBV. Nephrotic syndrome developed at initial presentation and was associated with MN on biopsy. The patient cleared the virus from blood, which was associated with eventual resolution of the MN. We postulate that EB viremia in patients lacking a fully competent immune system, but without a renal allograft, may create a susceptible environment for chronic systemic EB antigenemia that can then lead to immune-complex MN in the kidney. The association of EBV with renal histological changes consistent with MN has been suggested but not directly described before.