Pediatric Tubulointerstitial Nephritis

Tubulointerstitial nephritis (TIN) is an immunologically mediated inflammation of renal tubulointerstitium with relative sparing of glomeruli and vessels. Clinical symptoms and laboratory findings of TIN are often unspecific, resulting in a delayed diagnosis, which may lead to a poorer clinical outcome. Renal biopsy is the gold standard of the diagnosis and shows an inflammatory interstitial infiltrate and interstitial edema. Drug-induced TIN accounts for most cases, with antibiotics, proton-pump inhibitors, and NSAIDs as leading etiologic agents. TIN can be diagnosed in association with infections, systemic disease, uveitis, and toxic factors. TIN can be acute and reversible if the offending factor is withdrawn, or may represent a chronic process leading to irreversible renal failure. The role of corticosteroids and other immunosuppressive agents in the treatment of acute TIN is controversial.