The Value of Serum Concentration of Cystatin C as a Marker for Glomerular Filtration Rate in Children and Adolescents

Jung, Young Su; Lim, In Seok

Abstract

PURPOSE
Cystatin C has been proposed for the assessment of glomerular filtration rate, being more accurate than creatinine determination. We measured serum cystatin C concentrations in the pediatric population, and analysed the correlation between cystatin C and glomerular filtration rate. METHODS: Cystatin C and creatinine were measured by the particle enhanced nephelometric immunoassay and Jaff'e method, respectively, in 276 children and adolescents without evidence of kidney disease. The glomerular filtration rate was estimated by Schwartz's formula. RESULTS: The mean serum cystatin C concentration was significantly higher in infants under the age of 12 months than in older population. There was a negative correlation between cystatin C and age under 12 months, but not a significant change of cystatin C with age in children older than 12 months For children older than 12 months, the reference range of cystatin C was 0.46-1.05 mg/L. On the other hand, there was a positive correlation between creatinine and age in the whole population. We also observed a positive correlation between estimated glomerular filtration rate and 1/ cystatin C. CONCLUSION: The measurement of cystatin C is more practical than creatinine for estimating glomerular filtration rate in the pediatric population.