Clinical histories and renal biopsies were reviewed in 12 children with
acute tubulointerstitial nephritis, which was
drug related in eight, idiopathic in one, and multifactorial in three. Presentation with rashes and
hypertension was most common in patients with
drug-associated
nephritis. Eosinophils, which were present in the majority of the renal biopsies, did not distinguish between
drug-related and non-
drug-related disease. The majority of the children had a good outcome irrespective of the insulting agent. Frequent tubular basement membrane breaks were identified in seven of the biopsies but were not associated with a poor outcome. Proximal tubule brush border thinning, demonstrated by
periodic acid-Schiff and Tetragonolobus lotus staining, paralleled the severity of
acute renal failure.
Lectin and immunohistochemical techniques to identify proximal tubules (Tetragonolobus lotus), thick ascending limb of Henle (anti-
Tamm-Horsfall protein antibodies), and collecting ducts (Arachis hypogaea) allowed better delineation of sites of
inflammation and injury, showed collecting tubules to be involved in all cases, and demonstrated that small atrophic tubules were able to maintain the ability to
stain with the appropriate
lectin/antibody. It is proposed that studies using these techniques may better identify the nephron sites involved in a variety of renal diseases involving tubular segments.