Idiopathic acute interstitial nephritis: characterization of the infiltrating cells in the renal interstitium as T helper lymphocytes.

A previously healthy 39-year-old man presented with acute renal failure. There was no history of exposure to drugs nor was there any infection. Renal biopsy revealed interstitial nephritis with extensive acute degenerative changes in the tubules and extensive interstitial infiltration with mononuclear cells and no eosinophils. Monoclonal antibody staining studies identified the cells in the renal interstitium to be a helper/inducer subset of T lymphocytes. We suggest that a delayed hypersensitivity mechanism played a pathogenetic role in this patient's idiopathic acute interstitial nephritis.