RESUMO
Acute interstitial nephritis (AIN) is a relevant cause of acute renal failure. Drugs are the predominant cause, followed by infections and idiopathic lesions. AIN, as a form of hypersensitivity reaction, is an uncommon manifestation in the setting of human parasitic infections. We report a case of a polyparasitic infection (Giardia lamblia, Entamoeba coli, and Endolimax nana) resulting in a severe biopsy-proven AIN in a 61-year-old male patient. Despite the antiparasitic treatment followed by corticosteroid therapy, and during the 6-month follow-up period, the patient remained dialysis-dependent, and he developed autoimmune hemolytic anemia. Extensive search for another infection or neoplasia was negative. Immunological tests were also negative. The resulting hypersensitivity reaction to the triple parasite infection would have led to fatal evolution for the kidneys affected by this unusual type of AIN.