Late effects on renal glomerular and tubular function in childhood cancer survivors

Abstract

BACKGROUND: Late nephrotoxicity among childhood cancer survivors is poorly documented. METHODS: We investigated 115 patients and 86 controls assessing serum cystatin C concentration (CysC), urinary N-acetyl-beta-D-glucosaminidase activity (NAG), and microalbuminuria. Proteinuria was quantified and electrophoresis performed. Polymorphism of the angiotensin convertase enzyme (ACE) gene was determined by genomic PCR. RESULTS: CysC was elevated in Wilms tumor (WT) patients. Gross proteinuria was observed in 30 patients including three patients with progressive proteinuria who improved on ACE-inhibitor treatment. Neither patients with proteinuria nor the entire study population differed from controls with respect to ACE polymorphism. Pathologically elevated urinary NAG was noted in 38% of leukemia/lymphoma, 54% of solid tumor, 20% of WT survivors. A similar distribution of pathological microalbuminuria was found. CONCLUSIONS: Mild-to-moderate subclinical glomerular and tubular damage can be identified in many childhood cancer survivors. However, most patients experience some spontaneous recovery from acute nephrotoxicity.