Is urinary type IV collagen a good marker of early impairment of renal function in childhood cancers survivors?

Introduction: Nephrotoxicity, as a side effect of antineoplastic treatment, can occur in childhood cancer survivors (CCSs). It worsens their quality of life especially if it leads to chronic kidney disease (CKD). Collagen turnover is known to be disturbed in CKD. Urinary type IV collagen (U-Col4) is recognized as an exponent of extracellular matrix synthesis and degradation in glomeruli and is thus involved in this turnover. The purpose of this study was to evaluate the usefulness of U-Col4 in assessing early renal impairment in CCSs. Material and methods: Seventy-eight CCSs, without CKD, bilateral kidney tumors, congenital kidney defects, urinary tract infections and diabetes, at least one year after ending antineoplastic treatment, and aged 1–18 years, were divided into three groups: 1) patients after nephroblastoma treatment (n = 18); 2) patients after other solid tumors treatment (n = 42); and 3) patients after anti-hamatopoietic and lymphatic system proliferative treatment (n = 18). Concentrations of creatinine and cystatin C