title: Accuracy of different equations in estimating GFR in pediatric kidney transplant recipients.
abstract: OBJECTIVE
  The knowledge of renal function is crucial for the management of pediatric kidney transplant recipients. In this population, the most commonly used plasma creatinine (PCr)-based or cystatin C (CystC)-based GFR-predicting formulas may underperform (e.g., corticosteroids and trimethoprim may affect PCr concentration, whereas prednisone and calcineurin inhibitors may affect CystC concentration). This study evaluated the performance of six formulas in pediatric kidney transplant recipients.
  
  
  METHODS
  The study used PCr-based formulas (bedside Schwartz, Schwartz-Lyon), CystC-based formulas (Hoek, Filler), and combined PCr-CystC-based formulas (CKD in Children [CKiD] 2012 and Zappitelli). The performance of these formulas was compared using inulin clearance as reference and assessed according to CKD stages in a historical cohort that included 73 pediatric kidney transplant recipients (199 measurements). The ability of the formulas to identify GFRs<60, <75, and <90 ml/min per 1.73 m(2) was assessed.
  
  
  RESULTS
  At measured GFR (mGFR) ≥90 ml/min per 1.73 m(2) (nine patients; 23 measurements), the Zappitelli formula had the highest 30% accuracy (P30) (95% [95% confidence interval (95% CI), 87% to 100%]) and the bedside Schwartz had the highest 10% accuracy (P10) (56% [95% CI, 32% to 72%]). At mGFR≥60 and <90 ml/min per 1.73 m(2) (22 patients; 91 measurements), all formulas had P30 values >80%. However, only the CKiD 2012 formula had a P10 value >50%. At mGFR<60 ml/min per 1.73 m(2) (42 patients; 85 measurements), the CKiD 2012 and Schwartz-Lyon formulas had the highest P10 (45% [95% CI, 34% to 55%] and 43% [95% CI, 33% to 54%]) and P30 (90% [95% CI, 84% to 97%] and 91% [95% CI, 86% to 98%]). All studied equations except Hoek and Filler had areas under the receiver-operating characteristic curves significantly >90% in discriminating patients with renal dysfunction at various CKD stages (GFR<60, <75, and <90 ml/min per 1.73 m(2)).
  
  
  CONCLUSIONS
  In pediatric kidney transplant recipients, the CKiD 2012 formula had the best performance at mGFRs<90 ml/min per 1.73 m(2). CystC-based formulas were not superior to PCr-based formulas.
authors.affiliation: Universidade Federal do Rio Grande do Sul, Programa de Pós graduação em Saúde da Criança e do Adolescente, Porto Alegre, Brazil; Universidade de Caxias do Sul, Centro de Ciências da Saúde, Caxias do Sul, Brazil; Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot, Fellow CAPES-Foundation, Ministry of Education of Brazil, Brasilia/DF, Brazil;
authors.forename: Vandréa
authors.initials: V
authors.lastname: de Souza
authors.affiliation: Centre de Référence des Maladies Rénales Rares, Service de Néphrologie et Rhumatologie Pédiatriques, and Université Claude Bernard, Lyon 1, Lyon, France; CNRS UMR 5305, Biologie tissulaire et Ingénierie thérapeutique, Lyon, France;
authors.forename: Pierre
authors.initials: P
authors.lastname: Cochat
authors.affiliation: Université Claude Bernard, Lyon 1, Lyon, France; Service de Biostatistique, Hospices Civils de Lyon, Lyon, France; CNRS UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biostatistique-Santé, Villeurbanne, France; and.
authors.forename: Muriel
authors.initials: M
authors.lastname: Rabilloud
authors.affiliation: Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot, Fellow CAPES-Foundation, Ministry of Education of Brazil, Brasilia/DF, Brazil; Universidade de Caxias do Sul, Centro de Ciências da Saúde, Caxias do Sul, Brazil; Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Luciano
authors.initials: L
authors.lastname: Selistre
authors.affiliation: Universidade Federal do Rio Grande do Sul, Programa de Pós graduação em Saúde da Criança e do Adolescente, Porto Alegre, Brazil; Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Mario
authors.initials: M
authors.lastname: Wagner
authors.affiliation: Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot, Université Claude Bernard, Lyon 1, Lyon, France;
authors.forename: Aoumeur
authors.initials: A
authors.lastname: Hadj-Aissa
authors.affiliation: Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot.
authors.forename: Olga
authors.initials: O
authors.lastname: Dolomanova
authors.affiliation: Centre de Référence des Maladies Rénales Rares, Service de Néphrologie et Rhumatologie Pédiatriques, and.
authors.forename: Bruno
authors.initials: B
authors.lastname: Ranchin
authors.affiliation: Université Claude Bernard, Lyon 1, Lyon, France; Service de Biostatistique, Hospices Civils de Lyon, Lyon, France; CNRS UMR 5558, Laboratoire de Biométrie et Biologie Evolutive, Equipe Biostatistique-Santé, Villeurbanne, France; and.
authors.forename: Jean
authors.initials: J
authors.lastname: Iwaz
authors.affiliation: Exploration Fonctionnelle Rénale et Métabolique, Groupement Hospitalier Edouard Herriot, Université Claude Bernard, Lyon 1, Lyon, France; CNRS UMR 5305, Biologie tissulaire et Ingénierie thérapeutique, Lyon, France; laurence.dubourg@univ-lyon1.fr.
authors.forename: Laurence
authors.initials: L
authors.lastname: Dubourg
mesh_terms: D000293:Adolescent; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D002648:Child; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007444:Inulin / Q000378:metabolism; D007668:Kidney / Q000502:physiology*; D016030:Kidney Transplantation; D008297:Male; D055641:Mathematical Concepts; D012372:ROC Curve; D051436:Renal Insufficiency, Chronic / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D007444:Inulin; D003404:Creatinine
keywords: children; kidney transplantation; renal function