Ifosfamide-induced subclinical tubular nephrotoxicity despite mesna.

We monitored acute tubular damage in 16 patients who received a 5-day course of ifosfamide (1.6 g/m2/day) and mesna (1.2 g/m2/day) therapy. Urinary concentrations of alanine aminopeptidase, N-acetyl-beta-D-glucosaminidase, and total protein increased in every patient, but the extent of tubular toxicity varied widely among patients. Evidence of toxicity was greatest in patients whose tumors involved the kidneys. The time course of enzymuria and proteinuria indicated tubular cell necrosis. We observed this acute toxic effect despite the administration of sufficient mesna to prevent hemorrhagic cystitis. Urinary marker concentrations returned towards pre-dose levels, and there were no increases in serum creatinine concentrations measured 3 weeks after treatment.