title: Impact of age on reference values for serum concentration of cystatin C in children.
abstract: Recently, cystatin C (cyst C) was proposed for the assessment of glomerular filtration rate, being more accurate than creatinine determination. Reference intervals for cyst C do not vary with age and sex, like creatinine values. Elevated values of cyst C were reported for pre- and full-term infants. Nevertheless, the age cut-off for stable cyst C values i.e., age independence, remains under discussion. Therefore, we conducted a prospective study in 98 healthy children, 51 being under 18 months of age. Cyst C was determined by the nephelometric method. The infants under the age of 18 months had a higher mean serum cyst C value (0.94 +/- 0.24 mg/l) than the older children (0.65 +/- 0.19 mg/l). There was a negative correlation between age and cyst C in the infant group under the age of 18 months (r(2)=0.631, P<0.01). Our results indicate that mean serum cyst C is higher in infants than older children; the age cut-off appears over the age of 1 year of life, presumably reflecting kidney maturation. Our study does not allow accurate assessment of the age cut-off at 18 months or 36 months.
authors.affiliation: Nephrology Dialysis Transplantation Children's Unit, CHU Hautepierre, Avenue Molière, 67098 Strasbourg, France. Michel.Fischbach@chru.strasbourg.fr
authors.forename: M
authors.initials: M
authors.lastname: Fischbach
authors.forename: V
authors.initials: V
authors.lastname: Graff
authors.forename: J
authors.initials: J
authors.lastname: Terzic
authors.forename: V
authors.initials: V
authors.lastname: Bergère
authors.forename: M
authors.initials: M
authors.lastname: Oudet
authors.forename: G
authors.initials: G
authors.lastname: Hamel
mesh_terms: D000375:Aging / Q000097:blood*; D002675:Child, Preschool; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D006801:Humans; D011446:Prospective Studies; D012016:Reference Values
chemical_list: C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins