title: Diagnostic accuracy of serum cystatin C in chronic kidney disease: a meta-analysis.
abstract: BACKGROUND
  Chronic kidney disease (CKD) is a major health problem worldwide with dramatically increasing incidence and prevalence. Serum cystatin C (sCysC) has been clarified by many studies as a relatively accurate marker to evaluate renal function.
  
  
  METHODS
  Meta-analysis of diagnostic test studies.
  
  
  METHODS
  Various clinical settings of CKD, including adult patients with diabetes, renal transplant patients, and so on.
  
  
  METHODS
  A computerized search of PubMed, Cochrane clinical trial database, and Current Contents (from inception until June 16, 2014) was performed to identify potentially relevant articles.
  
  
  METHODS
  Increased sCysC concentration.
  
  
  METHODS
  The measured glomerular filtration rate measured by nuclear medicine techniques such as 99Tc-diethylene triamine pentacaetic acid (99Tc-DTPA) or 51Cr-ethylenediamine tetra-acetic acid (51Cr-EDTA), or calculated by Cockcroft-Gault (CG) or Modification of Diet in Renal Disease (MDRD) formula or 24 hours creatinine clearance rate.
  
  
  RESULTS
  In total 19 studies were included in this study. Across all settings, the diagnostic odds ratio (DOR) of sCysC in predicting CKD was 40 (95% CI, 26 - 61) when sensitivity and specificity was 0.85 (95% CI, 0.81 - 0.89) and 0.87 (95% CI, 0.84 - 0.90), respectively. The area under the curve for the receiver-operating characteristic (AUROC) of sCysC to predict CKD was 0.92 (95% CI, 0.90 - 0.94). For the diagnostic value of sCysC in diabetics with CKD, the DOR was 51 (95% CI, 22 - 122), with sensitivity and specificity of 0.89 and 0.87, respectively. Subgroup analysis showed that sCysC was of better diagnostic value in the West than in Asia, and the diagnostic value of sCysC assayed by particle-enhanced nephelometric immunoassay (PENIA) was higher than sCysC assayed by particle-enhanced turbidimetric immunoassay (PETIA).
  
  
  CONCLUSIONS
  SCysC appears to be a good biomarker in the definition of CKD. However, its performance is different in subgroups restricted by clinical settings, race, and sCysC assay.
authors.affiliation: Department of Geriatrics, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Wei
authors.forename: Xiaoshuang
authors.initials: X
authors.lastname: Ye
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Pei
authors.forename: Jianqing
authors.initials: J
authors.lastname: Wu
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhao
mesh_terms: D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000652:urine; D055316:Cystatin C / Q000097:blood*; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007677:Kidney Function Tests / Q000706:statistics & numerical data; D009391:Nephelometry and Turbidimetry / Q000706:statistics & numerical data; D012372:ROC Curve; D051436:Renal Insufficiency, Chronic / Q000097:blood* / Q000175:diagnosis; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine