title: Performance evaluation of a particle-enhanced turbidimetric cystatin C assay using the Abbott Aeroset analyser and assessment of cystatin C-based equations for estimating glomerular filtration rate in chronic kidney disease.
abstract: BACKGROUND
  Measurement of glomerular filtration rate (GFR) is critical for the diagnosis and stratification of chronic kidney disease (CKD). Recent studies have shown that cystatin C is superior to creatinine for the detection of impaired GFR, and several cystatin C-based equations for estimating GFR have been developed for this clinical application. We conducted the present study to assess the applicability of cystatin C as a routine clinical laboratory index and to determine the performance of cystatin C-based equations in estimating GFR in CKD patients in China.
  
  
  METHODS
  Performance evaluation of particle-enhanced turbidimetric cystatin C assay on the Abbott Aeroset analyser was carried out according to the National Committee for Clinical Laboratory document EP10-A2. Estimated GFR, which was generated from cystatin C-based equations, was compared with measured GFR, which was detected by plasma clearance of 99mTc-DTPA.
  
  
  RESULTS
  Our cystatin C assay showed a very low total imprecision and linearity drift. All eight cystatin C-based GFR estimating equations underestimated or overestimated GFR as compared with GFR determined by 99mTc-DTPA clearance.
  
  
  CONCLUSIONS
  Although the cystatin C assay is acceptable for routine clinical laboratory monitoring, none of the existing cystatin C-based equations were ideal for estimating GFR in Chinese CKD patients.
authors.affiliation: Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Sun
authors.forename: Tang
authors.initials: T
authors.lastname: Jiang
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Zeng
authors.forename: Peisong
authors.initials: P
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry / Q000379:methods*
chemical_list: D055316:Cystatin C