title: GFR is better estimated by considering both serum cystatin C and creatinine levels.
abstract: Serum cystatin C (cysC) is a potential marker of the glomerular filtration rate (GFR) that has generated conflicting reports in children. A prospective study was conducted to assess the benefit of considering cysC together with serum creatinine (SCr) and demographic and morphologic characteristics to better estimate the 51Cr-ethylenediaminetetraacetate (EDTA) clearance (CL), i.e., the GFR. Plasma 51Cr-EDTA data from 100 children or young adults (range: 1.4-22.8 years old) were analyzed according to the population pharmacokinetic approach by using the nonlinear mixed effects model (NONMEM) program. The actual CL was compared to the CL predicted according to different covariate equations. The best covariate equation (+/-95% confidence interval) was: GFR (ml/min)=63.2(+/-3.4) . [(SCr (microM)/96)(-0.35 (+/-0.20))] . [(cysC (mg/l)/1.2)(-0.56 (+/-0.19))] . [(body weight (kg)/45)(0.30 (+/-0.17))] . [age (years)/14)(0.40 (+/-0.16))]. This equation was associated with a less biased and more precise estimation than the Schwartz equation. CysC improves the estimation of the GFR in children if considered with other covariates within the mathematical formula.
authors.affiliation: Department of Clinical Biology and EA3035, Institut Claudius-Regaud, Toulouse, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Bouvet
authors.forename: François
authors.initials: F
authors.lastname: Bouissou
authors.forename: Yvon
authors.initials: Y
authors.lastname: Coulais
authors.forename: Sophie
authors.initials: S
authors.lastname: Séronie-Vivien
authors.forename: Mathieu
authors.initials: M
authors.lastname: Tafani
authors.forename: Stéphane
authors.initials: S
authors.lastname: Decramer
authors.forename: Etienne
authors.initials: E
authors.lastname: Chatelut
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002860:Chromium Radioisotopes; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D004492:Edetic Acid / Q000378:metabolism; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007223:Infant; D008297:Male
chemical_list: C525030:CST3 protein, human; D002860:Chromium Radioisotopes; D055316:Cystatin C; D015891:Cystatins; D004492:Edetic Acid; D003404:Creatinine