Copeptin as a potential biomarker of chronic kidney disease to predict the disease progression in children with chronic kidney disease

Background: Biomarkers to predict the onset and progression of chronic kidney disease (CKD) in children are lacking, and no such definite biomarkers have been implicated in the diagnosis of CKD. We conducted this study to evaluate copeptin as a CKD marker and predict the disease progression by estimating the copeptin levels at baseline and 12 months follow-up in children with CKD stage 2 and above. Materials and Methods: This prospective single-centre cohort study was conducted in children under 14 years with CKD stages 2-4. Blood and urine samples were collected at enrolment and 1-year follow-up for routine investigations and serum copeptin, cystatin C and urinary neutrophil gelatinase-associated lipocalcin (uNGAL) estimation. Results: A total of 110 children (60 cases and 50 controls) were enrolled in the study. The mean estimated glomerular filtration rate (eGFR) of cases was 58.3 +/- 18.7 ml/min/1.73 m(2). Among the cases, there was a significant rise in the serum copeptin levels from baseline 483.08 +/- 319.2 pg/ml to follow-up at 1 year, that is, 1046.82 +/- 823.53 pg/ml (P < 0.0001). A significant difference was noted in the baseline values of serum cystatin C, that is, 1512.98 +/- 643.77 ng/ml and 719.68 +/- 106.96 ng/ml (P < 0.0001), and uNGAL, that is, 13.53 +/- 11.72 and 1.76 +/- 2.37 ng/ml (P < 0.0001) between the cases and controls. There was no significant correlation (correlation coefficient = 0.10) between change in eGFR and copeptin levels during 12 months of follow-up. Conclusion: No significant correlation was found between the change in eGFR and copeptin levels during 12 months of follow-up. This can be due to the slow deterioration of renal functions, as most of the cases had underlying congenital anomalies of the kidney and urinary tract (CAKUT), which is known to have a slow progression of CKD and a small sample size.