The aim of work was to investigate whether serum and urinary neutrophil gelatinase-associated lipocalin(sNGAL and uNGAL, respectively) are potential biomarkers of early cyclosporine A (CsA) nephrotoxicity in steroid-dependent nephrotic children (SDNS). The study group (I) consisted of 19 children with SDNS aged 9.46+/-5.52 years treated with CsA. The children were examined four times: at proteinuria relapse, prior to CsA treatment,then after 3, 6, and 12 months of CsA treatment. The control group (II) consisted of 18 healthy children aged 3-15 years. A commercial enzyme-linked immunosorbent assay method was used to measure NGAL concentration.The sNGAL level in SDNS children prior to the administration of CsA was similar to that in the healthy controls (p>0.05), but it increased significantly during the course of treatment (p<0.01). The uNGAL/creatinine (cr) ratio in SDNS patients was higher before the withdrawal of CsA therapy (p<0.05), and was also increased at the consecutive examinations (p<0.01). There was a positive correlation between both sNGAL and uNGAL levels and CsA serum level. However, based on the serum and urinary NGAL/cr receiver operating characteristic curve and area under the curve (AUC) analysis, it remains uncertain whether uNGAL is a good predictor of cyclosporine nephropathy. Both sNGAL and uNGAL concentrations increased during the course of CsA treatment. Further studies in larger groups of patients are therefore necessary to confirm our experimental data that increased NGAL levels may be a non-invasive marker for the early detection of tubulointerstitial damage in CsA nephrotoxicity.

Urinary NGF levels were significantly elevated in patients with myelomeningocele. Future studies are needed to examine further the significance of urinary NGF levels in the pathogenesis of neurogenic bladder in this clinical condition.

BackgroundThe objective of this study was to establish age-dependent values for urinary renalase/creatinine (renalase/Cr) ratio in healthy children and adolescents.MethodsThe study was conducted on a random sample of 157 healthy children and adolescents (0.1–17.9 years) divided into six age groups in 3-year intervals. Urine renalase concentration was measured using an enzyme-linked immunosorbent assay (ELISA) kit (Uscn Life Science, Wuhan, China).ResultsWe analyzed median urine renalase/Cr ratio in particular age groups with the use of analysis of variance (ANOVA). Renalase/Cr levels were significantly higher in the youngest children < 3 years in comparison with other age groups (4.07 ng/mg Cr, p < 0.05). There was a statistically significant negative correlation between urine renalase/Cr and body mass index (BMI) Z-score (r = −0.22, p < 0.05) and both systolic (r = −0.22, p < 0.05) and diastolic (r = −0.21, p < 0.05) blood pressure. We constructed the reference renalase/Cr percentiles according to age in 3-year intervals.ConclusionsTo the best of our knowledge, this study is the first to present reference values of urine renalase excretion in a healthy pediatric population. Further studies should concentrate on the influence of increased blood pressure or obesity on urine renalase excretion in children and teenagers.

The present pilot study has clearly demonstrated that children with UPJO showed increased uAGT levels, which correlated negatively with differential renal function in radionuclide scan.

Increased pSDMA and sCysC levels were found in CKD children. Further studies are required to confirm potential applications of pSDMA and CysC as useful biomarkers for the diagnosis and progression of CKD.