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Keywords:

GFR-predicting-equations, children, height-independent GFR-predicting equation, Schwartz equation, Science & Technology, Life Sciences & Biomedicine, Pharmacology & Pharmacy, 1115 Pharmacology and Pharmaceutical Sciences, 3214 Pharmacology and pharmaceutical sciences

Abstract:

Height-independent GFR predicting equation in children: a possible routine screening tool for kidney disease in laboratories Laurence DUBOURGa, Vandrea DE SOUZAb, Régine CARTIERc, Olga DOLOMANOVAd, Bruno RANCHINe, Pierre COCHATf, Luciano SELISTREg, Sandrine LEMOINEh, Aoumeur HADJ-AISSAi, Hans POTTELj a Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot, Hospices Civils de Lyon, Université Claude-Bernard, Lyon- Biologie tissulaire et Ingénierie thérapeutique, UMR 5305 CNRS/Université Claude-Bernard, Lyon - FRANCE, b Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot, Hospices Civils de Lyon, Universidade de Caxias do Sul- Centro de Ciências da Saúde- School of Medicine-Brazil-FAMED, Programa de Pos Graduação em Saude da Criança, Lyon - FRANCE, c Groupement Hospitalier Est, Centre de Biologie et de Pathologie Est Biochimie et Biologie Moléculaire, Hospices Civils, Lyon - FRANCE, d Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot, Hospices Civils, Lyon - FRANCE, e Centre de Réference des Maladies Rénales Rares, Service de Néphrologie et Rhumatologie Pédiatriques, Hospices Civils, Lyon - FRANCE, f Centre de Réference des Maladies Rénales Rares, Service de Néphrologie et Rhumatologie Pédiatriques, Hospices Civils de Lyon- Université Claude-Bernard, Lyon- Biologie tissulaire et Ingénierie thérapeutique, UMR 5305 CNRS/Université Claude-Bernard, Lyon - FRANCE, g Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot, Hospices Civils de Lyon, Universidade de Caxias do Sul- Centro de Ciências da Saúde- School of Medicine-Brazil-Pontifícia Universidade Católica do Rio Grande do Sul, Lyon - FRANCE, h Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot, Hospices Civils de Lyon-Département de Néphrologie, Hospices Civils de Lyon -INSERM UMR 1060, Université Claude Bernard, Lyon - FRANCE, i Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot, Hospices Civils de Lyon, Université Claude-Bernard, Lyon - FRANCE, j Department of Clinical Chemistry, AZ Groeninge Hospital, Kortrijk, Belgium, Kortrijk - BELGIUM Objectives: According to KDOQI recommendations, determination of plasma creatinine (Pcr) should be associated to an estimation of GFR (eGFR). However, in the pediatric population, eGFR is rarely determined by laboratories as Schwartz formula requires height information, which is normally not available in clinical laboratory databases. Pottel et al. [1] developed a height-independent equation eDFG=107.3/(Pcr/Q) with Q = median of Pcr for each age class. The aim of the study was 1) to adapt this equation to our laboratory (Pottel-Lyon) and 2) to compare its performance to the original-Pottel equation and to the Schwartz equation. Methods: 1) All first Pcr determination performed in children (1 to 18 years old) in the pediatric hospital in 2010 and 2011were collected. Median of Pcr was determined for sex and each one-year-age-interval and considered as the locally adapted coefficient (Q-Lyon). 2) Among the whole population, 438 true measurements of GFR (mGFR, inulin or iohexol clearance, 359 children) were performed and compared to eGFR calculated by a) the Pottel-Lyon, b) the original-Pottel equation and c) the Schwartz equation. Pcr was determined by an IDMS-standardized enzymatic assay. Results: The local coefficient Q-Lyon was determined with the first Pcr measurement of 12219 children (53 % males, mean Pcr=43±44 [12-2122] µmol/L). Children with a mGFR (58% males) were aged of 10±3 years (3-18) with a mean Pcr of 55±28 (17-262) µmol/L and a mean of eGFR of 93±33 (18-204) ml/min/1.73m2. The Pottel-Lyon equation has a significant lower bias compared to the original-Pottel and to the Schwartz equation (0.9±21.2, 8.9±23.1 and 10.0±22.5, respectively) and a better 30% accuracy (87.0% vs 79.6% and 81.0%, respectively). The performance in identifying patients with renal dysfunction (GFR Discussion and conclusion: The GFR-predicting-equations (Schwartz, original Pottel and adapted Pottel-Lyon formulas) are reliable with a better performance of the adapted Pottel-Lyon equation. When height information is not available, the height-independent Pottel equation can be used by medical analysis laboratories as an excellent screening tool for kidney disease. Reference: 1. Pottel H, Pediatr Nephrol 2012 and Hoste L, NDT 2013.