Reference intervals for cystatin C in pre- and full-term infants and children

Abstract

Cystatin C is a non-glycated, 13-kDa basic protein produced by all nucleated cells. Recent studies have indicated that the plasma concentration of cystatin C is a better marker for glomerular filtration rate (GFR) than plasma creatinine, which is most commonly used for this purpose. We established reference values for plasma cystatin C in pre- or full-term infants and children. For comparison we also measured the creatinine concentration in the same samples. Cystatin C was measured by a commercially available immunoturbidimetric method with a Hitachi 704 analyzer in sera obtained from 58 pre-term infants, 50 full-term infants and 299 older children (132 girls, 167 boys, median age 4.17 years, range 8 days to 16 years). No sex differences were found. The pre-term infants had higher cystatin C concentrations (mean 1.88 mg/l, SD 0.36 mg/l) than the full-term (mean 1.70 mg/l, SD 0.26 mg/l, P=0.0145). The reference interval for pre-term infants calculated non-parametrically was 1.34-2.57 mg/l and for full-term infants 1.36-2.23 mg/l. The cystatin C concentration decreased rapidly after birth, and above 3 years of age did not depend on age. The reference interval for children 3-16 years of age calculated non-parametrically was 0.51-1.31 mg/l. Younger children (<1 year: 0.75-1.87 mg/l; 1-3 years: 0.68-1.60 mg/l) had slightly, but significantly, higher plasma cystatin C levels.

The usefulness of cystatin C and related formulae in pediatrics

“…Results obtained with the two main assays that are commercially available, namely the DAKO kit (turbidimetric, PETIA) and the Siemens Healthcare assay (nephelometric, PENIA), can be quite different, as recently demonstrated with the publication of reference intervals for healthy term and preterm infants. The results with the PENIA method in our study (79) were signifi cantly lower than those reported by Harmoinen et al (80) . Similar problems occurred when the results of the CKiD study were re-analyzed using PENIA, which lead to substantially better results (81) .…”

Early Predictors of Acute Kidney Injury (AKI) in a Sample of Egyptian Full Term Neonates

“…In our study, the results in 3rd day of incubation, both beta 2 microglobulin an cystatin C remained the studied neonates higher than in controls, This observation confirmed more advantages of beta2 microglobulin an cystatin C than routine serum creatinine as early biomarkers for neonatal AKI [12,22,[28][29][30][31][32][33][34].…”

Factors limiting usefulness of serum and urinary NGAL as a marker of acute kidney injury in preterm newborns

“…16 Its usefulness was attracted by the lack of dependence from muscle mass, however, evidence supporting superiority over sCr are still elusive. [16][17][18][19][20][21] A new potential biomarker postulated as a more sensitive parameter of AKI is NGAL. 22 The introduction of this parameter into routine diagnostic workup requires establishing the reference values and knowledge of methodological limitations.…”