RESUMO
Two cases of tubulointerstitial nephritis (TIN) with renal failure related to immunotherapy (case 1) and immunostimulation (case 2) have been described. Case 1: 18 years old male patient with hay fever was admitted because of rapid increase of serum creatinine from 1.1 mg/dl to 5.5 mg/dl, fever, weight loss and anemia which developed during 6 months after second course of immunotherapy. Case 2: 12 years old boy was admitted because of fever, weight loss and rapid progression to renal failure after treatment of pharyngitis with antibiotics and immunostimulant drug. In both patients renal biopsy was performed and TIN with huge lymphocytes T infiltrates was diagnosed. After 6 months treatment with corticosteroids renal function turned back to previous levels in both patients. Pathogenesis and treatment of TIN is discussed.