BACKGROUND: Cystatin C (CST3), a strong inhibitor of cysteine proteinases, is freely filtered by the kidney glomerulus and is reabsorbed by the tubules, where it is almost totally catabolized, with the remainder then eliminated in urine. In tubular diseases, it seems sensible to postulate that CST3 degradation would be reduced and consequently an increase in its urinary elimination would be observed. METHODS: We report here the development of an automatic quantitative assay to measure CST3 concentrations in urine using a Behring N-Latex Cystatin C kit on a BNII laser nephelometer. We tested its clinical relevance on several kidney disease patients. RESULTS: This assay is sensitive (limit of detection 0.008 mg/L) and precise (within- and between-day CVs < 4%). Reference values for freshly collected urine samples range from 0.03 to 0.18 mg/L. Mean urine CST3 concentrations obtained from 52 patients with kidney tubular disease (4.31 +/- 3.85 mg/L) were significantly higher than those for 60 controls (0.096 +/- 0.044 mg/L; p < 0.0001) and 47 glomerular disease patients (0.106 +/- 0.133 mg/L; p < 0.0001). CONCLUSION: Increased urinary CST3 concentrations allow the accurate detection of tubular dysfunction among pure and mixed nephropathies. Because of its ability to be processed on automated clinical chemistry analyzers, this assay could easily be used as an adjunct to the standard panel used to screen kidney pathologies, even in emergency situations.
BACKGROUND:Cystatin C (CST3), a strong inhibitor of cysteine proteinases, is freely filtered by the kidney glomerulus and is reabsorbed by the tubules, where it is almost totally catabolized, with the remainder then eliminated in urine. In tubular diseases, it seems sensible to postulate that CST3 degradation would be reduced and consequently an increase in its urinary elimination would be observed. METHODS: We report here the development of an automatic quantitative assay to measure CST3 concentrations in urine using a Behring N-Latex Cystatin C kit on a BNII laser nephelometer. We tested its clinical relevance on several kidney diseasepatients. RESULTS: This assay is sensitive (limit of detection 0.008 mg/L) and precise (within- and between-day CVs < 4%). Reference values for freshly collected urine samples range from 0.03 to 0.18 mg/L. Mean urine CST3 concentrations obtained from 52 patients with kidney tubular disease (4.31 +/- 3.85 mg/L) were significantly higher than those for 60 controls (0.096 +/- 0.044 mg/L; p < 0.0001) and 47 glomerular diseasepatients (0.106 +/- 0.133 mg/L; p < 0.0001). CONCLUSION: Increased urinary CST3 concentrations allow the accurate detection of tubular dysfunction among pure and mixed nephropathies. Because of its ability to be processed on automated clinical chemistry analyzers, this assay could easily be used as an adjunct to the standard panel used to screen kidney pathologies, even in emergency situations.
Authors: Frank Dieterle; Elias Perentes; André Cordier; Daniel R Roth; Pablo Verdes; Olivier Grenet; Serafino Pantano; Pierre Moulin; Daniel Wahl; Andreas Mahl; Peter End; Frank Staedtler; François Legay; Kevin Carl; David Laurie; Salah-Dine Chibout; Jacky Vonderscher; Gérard Maurer Journal: Nat Biotechnol Date: 2010-05 Impact factor: 54.908
Authors: Vishal S Vaidya; Sushrut S Waikar; Michael A Ferguson; Fitz B Collings; Kelsey Sunderland; Costas Gioules; Gary Bradwin; Roland Matsouaka; Rebecca A Betensky; Gary C Curhan; Joseph V Bonventre Journal: Clin Transl Sci Date: 2008-12 Impact factor: 4.689
Authors: Nicolas Roberto Robles; Candido Mena; Edgar Chavez; Miguel Angel Bayo; Boris Gonzalez Candia; Antonio Cidoncha; Juan Lopez Gomez; Juan Jose Cubero Journal: J Clin Lab Anal Date: 2017-02-10 Impact factor: 2.352