Accuracy of Urinary Epidermal Growth Factor to Creatinine Ratio to Predict 24-Hour Urine Epidermal Growth Factor and Interstitial Kidney Fibrosis in Patients with IgA Nephropathy.
Clin Lab
; 65(6)2019 Jun 01.
Article
em En
| MEDLINE
| ID: mdl-31232037
ABSTRACT
BACKGROUND:
Urinary levels of EGF may be a noninvasive biomarker of the degree of interstitial fibrosis. However, all the available data are based on studies that examined the EGF/creatinine ratio in spot urine samples. The agreement between EGF/creatinine ratio and 24-hours EGF excretion has not been analyzed, neither has it been established which of these two measurements is a better predictor of the degree of interstitial fibrosis. To investigate whether the EGF/creatinine ratio can predict 24-hours EGF, and which of these two measures is a better predictor of interstitial fibrosis in patients with IgA nephropathy (IgAN).METHODS:
This is a cross-sectional study including 80 patients with IgAN. EGF levels were measured by ELISA in spot second-morning and 24-hours urine samples. We analyzed the concordance between these two measures and their respective ability to predict interstitial kidney fibrosis.RESULTS:
The intraclass correlation coefficient between 24-hours and spot EGF/creatinine was 0.63 (95% CI 0.54 - 0.70), bias was 2.7 µg/mL (95% CI 2.1 - 7.5). Passing-Bablok regression did not show a significant deviation from linearity (p = 0.72). Bland-Altman showed a systematic and proportional error between both EGF measures. Spot EGF/creatinine ratios overestimated the 24-hours EGF at low excretion values and underestimated it at high excretion values. In univariate analyses, 24-hours excretion of EGF was a better predictor of interstitial fibrosis than spot EGF/creatinine ratio (R2 0.43 vs. 0.30, p = 0.000). In multivariate analyses, the 24-hours excretion of EGF plus GFR, significantly improved the prediction of interstitial fibrosis when compared with GFR alone (R2 0.52 vs. 0.39, p = 0.000). When spot-urine EGF was introduced instead of the 24-hours excretion, the model was statistically significant but had a lower predictive capacity (R2 0.46 spot EGF/creatinine vs. R2 0.52 24-hours EGF excretion, p = 0.000).CONCLUSIONS:
The 24-hours excretion of EGF should be considered as the first-choice measure to estimate the interstitial fibrosis. The EGF/creatinine ratio cannot accurately estimate the total EGF excretion of but it also improves the estimation of the fibrosis surface, and, consequently, could be an alternative whenever 24-hours urine samples cannot be obtained.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Biomarcadores
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Creatinina
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Fator de Crescimento Epidérmico
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Glomerulonefrite por IGA
Tipo de estudo:
Diagnostic_studies
/
Observational_studies
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Prevalence_studies
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Prognostic_studies
/
Risk_factors_studies
Limite:
Adult
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Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Clin Lab
Assunto da revista:
TECNICAS E PROCEDIMENTOS DE LABORATORIO
Ano de publicação:
2019
Tipo de documento:
Article