title: Intraindividual variability of the modified Schwartz and novel CKiD GFR equations in pediatric renal transplant patients.
abstract: GFR in children can be obtained from a formula using SCr and height or various formulas including serum CysC. Recently, two new GFR formulas have been developed: (i) height and SCr-mSchwartz GFR and (ii) height, SCr, CysC, and serum urea (CKiD GFR). While these formulas proved to be accurate when compared to the gold standard, their use in children post-kidney Tx is yet to be assessed. A total of 1174 blood samples (urea, SCr and CysC) were analyzed from the post-Tx period in 24 Tx children (12 boys, median age = 8.6 yr) currently followed at our institution. CKiD GFR and mSchwartz GFR were compared using Bland-Altman analysis and the CV. The mSchwartz GFR overestimated the CKiD GFR (mean bias = 1.09 ± 0.14; 95% limits of agreements from 0.82 to 1.36). Median CV of CKiD GFR (10.3%) was significantly lower than that of mSchwartz GFR (15.0%), p = 0.04, and negatively correlated with the slope of GFR (r(2) = 0.34, p = 0.0026). In conclusion, CKiD GFR has a significantly lower intraindividual variation than mSchwartz GFR and may be better suited for longitudinal follow-up of patients post-Tx.
authors: Department of Pediatrics, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada.
authors: Anne
authors: A
authors: Tsampalieros
authors: Nathalie
authors: N
authors: Lepage
authors: Janusz
authors: J
authors: Feber
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D055316:Cystatin C / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007223:Infant; D007677:Kidney Function Tests; D016030:Kidney Transplantation / Q000379:methods*; D008137:Longitudinal Studies; D008297:Male; D009398:Nephrology / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies
chemical_list: D055316:Cystatin C; D007166:Immunosuppressive Agents