Published in:
01-08-2015 | Original Article
New standardized cystatin C and creatinine GFR equations in children validated with inulin clearance
Authors:
Ulla B. Berg, Ulf Nyman, Rune Bäck, Magnus Hansson, Kajsa Åsling Monemi, Maria Herthelius, Jonas Björk
Published in:
Pediatric Nephrology
|
Issue 8/2015
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Abstract
Background
This study compares glomerular filtration rate (GFR) equations in children based on standardized cystatin C (CYSC) and creatinine (CREA) and their combinations with renal clearance of inulin (C-inulin).
Methods
A total of 220 children with different renal disorders were referred for C-inulin (median 84 ml/min/1.73 m2). Bias, precision (interquartile range, IQR), and accuracy (percentage of estimates ±30 % of C-inulin; P30) were evaluated for two cystatin C equations, CAPACYSC and BergCYSC, for creatinine equations, SchwartzCREA and GaoCREA, the arithmetic mean of CAPACYSC and SchwartzCREA (MEANCAPA+Schwartz), BergCYSC and SchwartzCREA (MEANBERG+SCHWARTZ) and the composite equation ChehadeCYSC+CREA.
Results
Overall results of CAPACYSC, BergCYSC, SchwartzCREA, GaoCREA, MEANCAPA+Schwartz, MEANBERG+SCHWARTZ and ChehadeCYSC+CREA were: median bias –7.6/–4.9/–3.7/–2.3/–4.6/–4.0/–10.1 %, IQR 20.0/19.9/21.7/22.4/21.0/20.9/23.3 ml/min/1.73 m2 and P30 86/86/80/83/89/91/83 %. The cystatin C equations, MEANCAPA+Schwartz and MEANBERG+SCHWARTZ had a more stable performance across subgroups compared with SchwartzCREA, GaoCREA and ChehadeCYSC+CREA.
Conclusions
Cystatin C was the preferred filtration marker for GFR estimation in children, while the benefit of combining cystatin C and creatinine deserves further investigations.