Renal function in children treated for central nervous system malignancies

Abstract

Aim: The aim of the study was to evaluate renal function and to assess the usefulness of the following nephrotoxicity markers: cystatin C (CYS C), beta-2 microglobulin (B2MG) and neutrophil gelatinase-associated lipocalin (NGAL) in 38 (18 girls, 20 boys) children previously treated for central nervous system malignancy. Material: Median age at evaluation was 13.7 years (range 2.1–22 years). The mean follow-up time after the completion of chemotherapy was 3.2 years (range 0.16–6.5 years). Results: Subclinical chronic kidney disease (estimated glomerular filtration rate: eGFR 90–60 ml/min/1.73 m2) was found in 22 patients (58 %), while renal insufficiency (eGFR 30–60 ml/min/1.73 m2) was found in six children (16 %). It has been demonstrated statistically significant negative correlation between the eGFR and cystatin C concentration (p < 0.0001) and eGFR and beta-2 microglobulin concentration (p < 0.02). Conversely, there was no correlation between eGFR and NGAL. Thirteen children (34 %) developed drug-induced tubulopathy: decreased tubular reabsorption of phosphate (TRP) and renal tubular threshold for phosphate (Tmp/GFR). Conclusion: Children treated for CNS tumours often develop drug-induced chronic renal disease, involving the glomeruli and/or renal tubules. Cystatin C and beta-2 microglobulin seemed to be good markers for chronic kidney damage in these patients, which is probably not true for NGAL.