The Assessment of Subclinical Ifosfamide-Induced Renal Tubular Toxicity Using Urinary Excretion of Retinol-Binding Protein

Abstract
The excretion of retinol-binding protein in early morning urine samples, expressed as a ratio to urinary creatinine (RBPCR), was used as a measure of proximal renal tubular toxicity in children during or after treatment with ifosfamide-containing chemotherapy. The results showed a progressive increase in renal tubular leak after exposure to ifosfamide that persisted after treatment. The toxic effect appeared to be greatest in younger children and at least partly dose-dependent, although partially reversible after each course of chemotherapy. However, few patients had related symptoms and none experienced major metabolic difficulty.