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 m(2)) was found in 22 patients (58 %), while renal insufficiency (eGFR 30-60 ml/min/1.73 m(2)) 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.
Keywords: Beta-2 microglobulin; Brain tumours; Cystatin C; Kidney injury; Neutrophil gelatinase-associated lipocalin.