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Published on: March 17, 2010

Impact of age on reference values for serum concentration of cystatin C in children

M Fischbach1, V Graff, J Terzic

  • 1Nephrology Dialysis Transplantation Children's Unit, CHU Hautepierre, Avenue Molière, 67098 Strasbourg, France. Michel.Fischbach@chru.strasbourg.fr

Pediatric Nephrology (Berlin, Germany)
|March 5, 2002
PubMed

Insights

Serum cystatin C (cyst C) levels are higher in infants than older children. Age-independent cyst C values in children likely emerge after one year, indicating kidney maturation.

Area of Science:

  • Pediatric Nephrology
  • Clinical Chemistry
  • Biomarker Assessment

Background:

  • Serum cystatin C (cyst C) is a proposed biomarker for glomerular filtration rate (GFR) assessment, offering potential advantages over serum creatinine.
  • While cyst C reference intervals are generally considered independent of age and sex, elevated levels are noted in infants, prompting investigation into age-related stability.
  • The precise age at which cyst C levels become stable and age-independent in children remains debated.

Purpose of the Study:

  • To prospectively investigate the relationship between serum cystatin C levels and age in healthy children.
  • To determine the age at which serum cystatin C values stabilize, indicating age independence.
  • To assess the utility of cystatin C in evaluating kidney maturation in pediatric populations.

Main Methods:

  • A prospective study was conducted involving 98 healthy children, with 51 participants under 18 months of age.
  • Serum cystatin C (cyst C) concentrations were measured using a nephelometric method.
  • Statistical analysis, including correlation, was performed to evaluate the relationship between age and cyst C levels.

Main Results:

  • Infants under 18 months exhibited significantly higher mean serum cystatin C levels (0.94 +/- 0.24 mg/l) compared to older children (0.65 +/- 0.19 mg/l).
  • A significant negative correlation (r(2)=0.631, P<0.01) was observed between age and serum cystatin C in infants younger than 18 months.
  • The findings suggest that serum cystatin C levels decrease with age during infancy, indicating ongoing physiological changes.

Conclusions:

  • Mean serum cystatin C levels are elevated in infants and decrease with age, suggesting kidney maturation.
  • The age cut-off for stable, age-independent cystatin C values appears to be after one year of life.
  • Further studies are needed to precisely define the age cut-off for cystatin C age independence at 18 or 36 months.

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