Ajay P Sharma1, Abeer Yasin, Amit X Garg, Guido Filler. 1. Department of Pediatrics, Division of Pediatric Nephrology, Children's Hospital, London Health Sciences Centre, University of Western Ontario, London, Ontario, N6A 5W9 Canada. guido.filler@lhsc.on.ca
Abstract
BACKGROUND AND OBJECTIVES: The diagnostic accuracy of cystatin C estimated GFR (eGFR) by various cystatin C equations have varied in different studies. We hypothesized that the GFR level of enrolled patients affects the diagnostic accuracy of a cystatin C equation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We analyzed 240 consecutively enrolled children at a single Canadian center in a prospective and cross-sectional study. Cystatin C was analyzed with nephelometry, and cystatin C eGFR was estimated by the equations validated in children. GFR was measured by technetium-99m-diethylene-triamine penta-acetic acid (⁹⁹m)Tc DTPA). RESULTS: We compared various cystatin C equations across GFR strata < 60, < 90, ≥ 135, and ≥ 150 ml/min per 1.73 m² for an accurate prediction and appropriate classification of the measured GFR. The CKiD, Zappitelli-CysEq, and Zappitelli-CysCrEq equations had a higher accuracy, estimated by eGFR values within 10% and 30% of the respective (99m)Tc DTPA, in the GFR categories < 60 and < 90 ml/min per 1.73 m², whereas the Bökenkamp, Bouvet, and Filler equations had a greater accuracy in the GFR categories ≥ 135 and ≥ 150 ml/min per 1.73 m². The Bouvet, CKiD, Filler, Zappitelli-CysEq, and Zappitelli-CysCrEq equations had a greater sensitivity to classify GFR < 60 and < 90 ml/min per 1.73 m², whereas the Bökenkamp equation had a higher sensitivity for GFR ≥ 135 and ≥ 150 ml/min per 1.73 m². CONCLUSIONS: The diagnostic accuracy of various cystatin C equations varies with GFR. This issue needs consideration while applying these equations in clinical practice and for further research on eGFR equations.
BACKGROUND AND OBJECTIVES: The diagnostic accuracy of cystatin C estimated GFR (eGFR) by various cystatin C equations have varied in different studies. We hypothesized that the GFR level of enrolled patients affects the diagnostic accuracy of a cystatin C equation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We analyzed 240 consecutively enrolled children at a single Canadian center in a prospective and cross-sectional study. Cystatin C was analyzed with nephelometry, and cystatin C eGFR was estimated by the equations validated in children. GFR was measured by technetium-99m-diethylene-triamine penta-acetic acid (⁹⁹m)Tc DTPA). RESULTS: We compared various cystatin C equations across GFR strata < 60, < 90, ≥ 135, and ≥ 150 ml/min per 1.73 m² for an accurate prediction and appropriate classification of the measured GFR. The CKiD, Zappitelli-CysEq, and Zappitelli-CysCrEq equations had a higher accuracy, estimated by eGFR values within 10% and 30% of the respective (99m)Tc DTPA, in the GFR categories < 60 and < 90 ml/min per 1.73 m², whereas the Bökenkamp, Bouvet, and Filler equations had a greater accuracy in the GFR categories ≥ 135 and ≥ 150 ml/min per 1.73 m². The Bouvet, CKiD, Filler, Zappitelli-CysEq, and Zappitelli-CysCrEq equations had a greater sensitivity to classify GFR < 60 and < 90 ml/min per 1.73 m², whereas the Bökenkamp equation had a higher sensitivity for GFR ≥ 135 and ≥ 150 ml/min per 1.73 m². CONCLUSIONS: The diagnostic accuracy of various cystatin C equations varies with GFR. This issue needs consideration while applying these equations in clinical practice and for further research on eGFR equations.
Authors: Derek K Ng; George J Schwartz; Michael F Schneider; Susan L Furth; Bradley A Warady Journal: Kidney Int Date: 2018-05-05 Impact factor: 10.612
Authors: Guido Filler; Ana Catalina Alvarez-Elías; Katherine D Westreich; Shih-Han S Huang; Robert M Lindsay Journal: Pediatr Nephrol Date: 2016-09-19 Impact factor: 3.714
Authors: Petter Bjornstad; Edward Nehus; Laure El Ghormli; Fida Bacha; Ingrid M Libman; Siripoom McKay; Steven M Willi; Lori Laffel; Silva Arslanian; Kristen J Nadeau Journal: Am J Kidney Dis Date: 2017-11-20 Impact factor: 8.860