title: Performance evaluation of the Sysmex Cystatin C assay on the Roche Modular P Analyzer.
abstract: OBJECTIVE
  Serum Cystatin C (CysC) is a promising endogenous marker for estimation of glomerular filtration rate. This study evaluated the analytical performance of the Sysmex CysC assay on the Roche Modular P Chemistry Analyzer (Modular P).
  
  
  METHODS
  The evaluation of imprecision, linearity, recovery, and interference were performed in accordance with the relevant Clinical and Laboratory Standards Institute guidelines protocols, using quality controls and patient samples. Comparison studies were conducted against the Siemens and Roche assay for CysC.
  
  
  RESULTS
  At CysC concentrations of 0.45 and 1.80mg/L, the within-run coefficient of variations (CVs) were 2.81% and 2.04%, respectively, and the between-run CVs were 3.14% and 3.26%. The CysC assay was proven throughout the measuring range from 0.10 to 8.00mg/L. Good correlations were achieved among the 3 CysC assays. The Sysmex assay appeared to report higher results than the Siemens assay. No interference was detected from hemoglobin 5g/L, bilirubin (free or conjugated) 200mg/L, or chyle 1500 formazin turbidity units.
  
  
  CONCLUSIONS
  The Sysmex CysC assay performed well with regard to basic performance, including precision, dilution linearity, and effects of interfering substances, and is an acceptable assay for the determination of CysC on the Modular P.
authors.affiliation: Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: He
authors.affiliation: Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, PR China.
authors.forename: Pei-Feng
authors.initials: PF
authors.lastname: Ke
authors.affiliation: Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, PR China.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Xu
authors.affiliation: Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, PR China.
authors.forename: Wei-Ye
authors.initials: WY
authors.lastname: Chen
authors.affiliation: Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, PR China.
authors.forename: Hai-Biao
authors.initials: HB
authors.lastname: Lin
authors.affiliation: Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, PR China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, PR China.
authors.forename: Yun-Xiu
authors.initials: YX
authors.lastname: Wang
authors.affiliation: Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, PR China.
authors.forename: Jun-Hua
authors.initials: JH
authors.lastname: Zhuang
authors.affiliation: Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, PR China. Electronic address: huangxz020@163.com.
authors.forename: Xian-Zhang
authors.initials: XZ
authors.lastname: Huang
mesh_terms: D015415:Biomarkers / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007674:Kidney Diseases / Q000097:blood / Q000175:diagnosis*; D007677:Kidney Function Tests / Q000379:methods*; D016014:Linear Models; D009391:Nephelometry and Turbidimetry; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; D055316:Cystatin C
keywords: Cystatin C; Glomerular filtration rate; Performance evaluation