Impact of age on reference values for serum concentration of cystatin C in children.
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.
Fischbach
M
M
Nephrology Dialysis Transplantation Children's Unit, CHU Hautepierre, Avenue Molière, 67098 Strasbourg, France. Michel.Fischbach@chru.strasbourg.fr
Graff
V
V
Terzic
J
J
Bergère
V
V
Oudet
M
M
Hamel
G
G
D000375:Aging / Q000097:blood*; D002675:Child, Preschool; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D006801:Humans; D011446:Prospective Studies; D012016:Reference Values
C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins