Počki (Oct 2017)

Cystatin C and chronic kidney disease in children

  • S.V. Kushnirenko,
  • Ye.M. Mordovets,
  • N.A. Tihonenko,
  • O.O. Markotenko

DOI
https://doi.org/10.22141/2307-1257.6.4.2017.114055
Journal volume & issue
Vol. 6, no. 4
pp. 190 – 199

Abstract

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Background. Determination of diagnostically significant values of serum concentration of cystatin C in combination with the estimated glomerular filtration rate (GFR) gives clinicians an advantage in clearly differentiation of chronic kidney disease stages in children and understanding the need for wider use of one of the most important diagnostic tests in the practice of a pediatric nephrologist and pediatrician. The aim of the study was to determine the diagnostic values of the serum concentration of cystatin C with the calculated glomerular filtration rate for the differentiation of the stage І–ІІІ chronic kidney disease. Materials and methods. In 119 children aged 2 to 17 years (7.3 ± 0.3 years), diagnostically significant values of serum cystatin C were determined to distinguish stage І–ІІІ chronic kidney disease, glomerular filtration rate was calculated based on the serum concentration of cystatin C using the equations of F.J. Hoek, M. Zappitelli, Pediatric GFR Calculator — The National Kidney Foundation (NKF). Results. In children with stage I chronic kidney disease, serum concentration of cystatin C was 0.77 ± 0.01 mg/l, which is significantly lower than the corresponding values in patients with chronic kidney disease stage ІІ (1.00 ± 0.01 mg/l) and stage ІІІ (1.58 ± 0.06 mg/l) (p < 0.05). The mean value of the concentration of cystatin C in the blood serum (0.77 ± 0.01 mg/l) in patients with stage I chronic kidney disease corresponded to the calculated glomerular filtration rate on the basis of cystatin C: 100.2 ± 1.6 ml/min/1.73 m2 determined according to the equation of F.J. Hoek, 103.6 ± 1.9 ml/min/1.73 m2 — according to the equation of M. Zappitelli and 90.4 ± 1.3 ml/min/1.73 m2 by the Pediatric GFR Calculator — NKF. The average value of cystatin C in the blood serum (1.00 ± 0.01 mg/l) in patients with stage II chronic kidney disease corresponded to the calculated glomerular filtration rate on the basis of cystatin C: 77.50 ± 0.87 ml/min/1.73 m2 according to the equation of F.J. Hoek, 77.60 ± 0.97 ml/min/1.73 m2 according to the equation of M. Zappitelli and 71.9 ± 0.7 ml/min/1.73 m2 by the Pediatric GFR Calculator-NKF. The average values of the estimated glomerular filtration rate based on cystatin C calculated by Pediatric GFR Calculator — NKF significantly differed from the results of the two previous equations (p < 0.05). Values of cystatin C in the blood serum (1.58 ± 0.06 mg/l) obtained in patients with stage III chronic kidney disease corresponded to almost identical estimated glomerular filtration rate on the basis of cystatin C determined from three different equations. Conclusions. The data obtained and the results of several stu­dies confirm that in children, cystatin C better correlates with the glomerular filtration rate than serum creatinine. Diagnostically significant values for the differentiation of stage І–ІІІ chronic kidney disease are determined. The informative value of the equations for calcula­ting the glomerular filtration rate on the basis of cystatin C was evaluated (F.J. Hoek, M. Zappitelli, Pediatric GFR Calculator — NKF).

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