BACKGROUND AND OBJECTIVE: Children with a solitary functioning kidney may develop CKD. Although widely used, equations to estimate GFR are not validated in these patients. This study sought to determine the precision of common estimating equations in the KIMONO (KIdney of MONofunctional Origin) cohort. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Two creatinine-based (estimated GFR [eGFR]-Schwartz, urinary creatinine clearance), two cystatin C-based (eGFR-Zappitelli1, eGFR-CKiD [Chronic Kidney Disease in Children] 1), and two cystatin C/creatinine-based (eGFR-Zappitelli2, eGFR-CKiD2) estimates were compared with the gold standard GFR measured by inulin single injection (GFR-inulin) in 77 children with a solitary functioning kidney (time span of assembly, 2005-2012). Included patients were 1.5-19.8 years of age. Kidney Disease Outcomes Quality Initiative (K/DOQI) classification was compared between GFR-inulin and eGFR methods to analyze misclassification by estimating equations. RESULTS: The eGFR-CKiD2 equation performed best in children with a solitary functioning kidney (mean bias, -0.9 ml/min per 1.73 m(2); 95% and 54% of values within ±30% and ±10% of GFR-inulin, respectively). Mean bias for eGFR-Schwartz was 0.4 ml/min per 1.73 m(2), with 90% and 33% of values within ±30% and ±10% of GFR-inulin, respectively. For all estimates, misclassification in K/DOQI stage ranged from 22% (eGFR-Zappitelli1) to 44% (urinary creatinine clearance) of children. CONCLUSIONS: Use of a combined serum cystatin C/creatinine-based equation (eGFR-CKiD2) is recommended to monitor renal function in children with a solitary functioning kidney. When cystatin C is not routinely available, eGFR-Schwartz should be used. Misclassification in K/DOQI-stage remains a caveat for all equations.
BACKGROUND AND OBJECTIVE:Children with a solitary functioning kidney may develop CKD. Although widely used, equations to estimate GFR are not validated in these patients. This study sought to determine the precision of common estimating equations in the KIMONO (KIdney of MONofunctional Origin) cohort. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Two creatinine-based (estimated GFR [eGFR]-Schwartz, urinary creatinine clearance), two cystatin C-based (eGFR-Zappitelli1, eGFR-CKiD [Chronic Kidney Disease in Children] 1), and two cystatin C/creatinine-based (eGFR-Zappitelli2, eGFR-CKiD2) estimates were compared with the gold standard GFR measured by inulin single injection (GFR-inulin) in 77 children with a solitary functioning kidney (time span of assembly, 2005-2012). Included patients were 1.5-19.8 years of age. Kidney Disease Outcomes Quality Initiative (K/DOQI) classification was compared between GFR-inulin and eGFR methods to analyze misclassification by estimating equations. RESULTS: The eGFR-CKiD2 equation performed best in children with a solitary functioning kidney (mean bias, -0.9 ml/min per 1.73 m(2); 95% and 54% of values within ±30% and ±10% of GFR-inulin, respectively). Mean bias for eGFR-Schwartz was 0.4 ml/min per 1.73 m(2), with 90% and 33% of values within ±30% and ±10% of GFR-inulin, respectively. For all estimates, misclassification in K/DOQI stage ranged from 22% (eGFR-Zappitelli1) to 44% (urinary creatinine clearance) of children. CONCLUSIONS: Use of a combined serum cystatin C/creatinine-based equation (eGFR-CKiD2) is recommended to monitor renal function in children with a solitary functioning kidney. When cystatin C is not routinely available, eGFR-Schwartz should be used. Misclassification in K/DOQI-stage remains a caveat for all equations.
Authors: Arend Bökenkamp; Cèleste A R C Laarman; Katja I Braam; Joanna A E van Wijk; Wijnanda A Kors; Marijke Kool; Janneke de Valk; Anna A Bouman; Marieke D Spreeuwenberg; Birgit Stoffel-Wagner Journal: Clin Chem Date: 2007-12 Impact factor: 8.327
Authors: Lyonne K van Rossum; Karlien Cransberg; Yolanda B de Rijke; Robert Zietse; Jan Lindemans; Arnold G Vulto Journal: Pediatr Nephrol Date: 2005-04-15 Impact factor: 3.714
Authors: Lesley A Inker; Christopher H Schmid; Hocine Tighiouart; John H Eckfeldt; Harold I Feldman; Tom Greene; John W Kusek; Jane Manzi; Frederick Van Lente; Yaping Lucy Zhang; Josef Coresh; Andrew S Levey Journal: N Engl J Med Date: 2012-07-05 Impact factor: 91.245
Authors: Rik Westland; Michiel F Schreuder; David F van der Lof; Annemieke Vermeulen; Inge M J Dekker-van der Meer; Arend Bökenkamp; Joanna A E van Wijk Journal: Pediatr Nephrol Date: 2014-06-09 Impact factor: 3.714
Authors: Emil den Bakker; Reinoud Gemke; Joanna A E van Wijk; Isabelle Hubeek; Birgit Stoffel-Wagner; Arend Bökenkamp Journal: Pediatr Nephrol Date: 2018-05-17 Impact factor: 3.714