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Estimation of GFR in Patients With Cystic Fibrosis: A Cross-Sectional Study

BACKGROUND: Patients with cystic fibrosis (CF) have frequent infectious complications requiring nephrotoxic medications, necessitating monitoring of renal function. Although adult studies have suggested that cystatin C (CysC)-based estimated glomerular filtration rate (eGFR) may be preferable due to...

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Autores principales: Wallace, Andrea, Price, April, Fleischer, Erin, Khoury, Michael, Filler, Guido
Formato: Online Artículo Texto
Lenguaje:English
Publicado: SAGE Publications 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6966245/
https://www.ncbi.nlm.nih.gov/pubmed/32002189
http://dx.doi.org/10.1177/2054358119899312
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author Wallace, Andrea
Price, April
Fleischer, Erin
Khoury, Michael
Filler, Guido
author_facet Wallace, Andrea
Price, April
Fleischer, Erin
Khoury, Michael
Filler, Guido
author_sort Wallace, Andrea
collection PubMed
description BACKGROUND: Patients with cystic fibrosis (CF) have frequent infectious complications requiring nephrotoxic medications, necessitating monitoring of renal function. Although adult studies have suggested that cystatin C (CysC)-based estimated glomerular filtration rate (eGFR) may be preferable due to reduced muscle mass of patients with CF, pediatric patients remain understudied. OBJECTIVE: Our objective was to determine which eGFR formula is best for estimating glomerular filtration rate (GFR) in pediatric patients with CF. METHODS: A total of 17 patients with CF treated with nephrotoxic antibiotics were recruited from the Children’s Hospital at London Health Sciences Centre, London, Ontario, Canada. (99)Tc DTPA GFR (measured GFR [mGFR]) was measured with 4-point measurements starting at 120 minutes using a 2-compartmental model with Brøchner-Mortensen correction, with simultaneous measurement of creatinine, urea, and CysC. The eGFR was calculated using 16 known equations based on creatinine, urea, CysC, or combinations of these. Primary outcome measures were correlation with mGFR, and agreement within 10% for various eGFR equations. RESULTS: Mean mGFR was 136 ± 21 mL/min/1.73 m(2). Mean creatinine, CysC, and urea were 38 ± 10 μmol/L, 0.72 ± 0.08 mg/L, and 3.9 ± 1.4 mmol/L, respectively. The 2014 Grubb CysC eGFR had the best correlation coefficient (r = 0.75, P = .0004); however, only 35% were within 10%. The new Schwartz formula with creatinine and urea had the best agreement within 10%, but a relatively low correlation coefficient (r = 0.63, P = .0065, 64% within 10%). CONCLUSIONS: Our study suggests that none of the eGFR formulae work well in this small cohort of pediatric patients with CF with preserved body composition, possibly due to inflammation causing false elevations of CysC. Based on the small numbers, we cannot conclude which eGFR formula is best.
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spelling pubmed-69662452020-01-30 Estimation of GFR in Patients With Cystic Fibrosis: A Cross-Sectional Study Wallace, Andrea Price, April Fleischer, Erin Khoury, Michael Filler, Guido Can J Kidney Health Dis Original Basic Research BACKGROUND: Patients with cystic fibrosis (CF) have frequent infectious complications requiring nephrotoxic medications, necessitating monitoring of renal function. Although adult studies have suggested that cystatin C (CysC)-based estimated glomerular filtration rate (eGFR) may be preferable due to reduced muscle mass of patients with CF, pediatric patients remain understudied. OBJECTIVE: Our objective was to determine which eGFR formula is best for estimating glomerular filtration rate (GFR) in pediatric patients with CF. METHODS: A total of 17 patients with CF treated with nephrotoxic antibiotics were recruited from the Children’s Hospital at London Health Sciences Centre, London, Ontario, Canada. (99)Tc DTPA GFR (measured GFR [mGFR]) was measured with 4-point measurements starting at 120 minutes using a 2-compartmental model with Brøchner-Mortensen correction, with simultaneous measurement of creatinine, urea, and CysC. The eGFR was calculated using 16 known equations based on creatinine, urea, CysC, or combinations of these. Primary outcome measures were correlation with mGFR, and agreement within 10% for various eGFR equations. RESULTS: Mean mGFR was 136 ± 21 mL/min/1.73 m(2). Mean creatinine, CysC, and urea were 38 ± 10 μmol/L, 0.72 ± 0.08 mg/L, and 3.9 ± 1.4 mmol/L, respectively. The 2014 Grubb CysC eGFR had the best correlation coefficient (r = 0.75, P = .0004); however, only 35% were within 10%. The new Schwartz formula with creatinine and urea had the best agreement within 10%, but a relatively low correlation coefficient (r = 0.63, P = .0065, 64% within 10%). CONCLUSIONS: Our study suggests that none of the eGFR formulae work well in this small cohort of pediatric patients with CF with preserved body composition, possibly due to inflammation causing false elevations of CysC. Based on the small numbers, we cannot conclude which eGFR formula is best. SAGE Publications 2020-01-15 /pmc/articles/PMC6966245/ /pubmed/32002189 http://dx.doi.org/10.1177/2054358119899312 Text en © The Author(s) 2020 https://creativecommons.org/licenses/by-nc/4.0/ This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).
spellingShingle Original Basic Research
Wallace, Andrea
Price, April
Fleischer, Erin
Khoury, Michael
Filler, Guido
Estimation of GFR in Patients With Cystic Fibrosis: A Cross-Sectional Study
title Estimation of GFR in Patients With Cystic Fibrosis: A Cross-Sectional Study
title_full Estimation of GFR in Patients With Cystic Fibrosis: A Cross-Sectional Study
title_fullStr Estimation of GFR in Patients With Cystic Fibrosis: A Cross-Sectional Study
title_full_unstemmed Estimation of GFR in Patients With Cystic Fibrosis: A Cross-Sectional Study
title_short Estimation of GFR in Patients With Cystic Fibrosis: A Cross-Sectional Study
title_sort estimation of gfr in patients with cystic fibrosis: a cross-sectional study
topic Original Basic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6966245/
https://www.ncbi.nlm.nih.gov/pubmed/32002189
http://dx.doi.org/10.1177/2054358119899312
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