title: Comparisons of creatinine and cystatin C for detection of kidney disease and prediction of all-cause mortality in HIV-infected women.
abstract: BACKGROUND
  Cystatin C could improve chronic kidney disease (CKD) classification in HIV-infected women relative to serum creatinine.
  
  
  METHODS
  Retrospective cohort analysis.
  
  
  METHODS
  Cystatin C and creatinine were measured from specimens taken and stored during the 1999-2000 examination among 908 HIV-infected participants in the Women's Interagency HIV study (WIHS). Mean follow-up was 10.2 years. Predictors of differential glomerular filtration rate (GFR) estimates were evaluated with multivariable linear regression. The associations of baseline categories (<60, 60-90, and >90 ml/min per 1.73 m) of creatinine estimated GFR (eGFRcr), cystatin C eGFR (eGFRcys), and combined creatinine-cystatin C eGFR (eGFRcr-cys) with all-cause mortality were evaluated using multivariable Cox regression. The net reclassification index (NRI) was calculated to evaluate the effect of cystatin C on reclassification of CKD staging.
  
  
  RESULTS
  CKD risk factors were associated with lower eGFRcys and eGFRcr-cys values compared with eGFRcr. Relative to eGFR more than 90, the eGFR less than 60 category by eGFRcys (Adjusted hazard ratio: 2.56; 95% confidence interval: 1.63-4.02), eGFRcr-cys (3.11; 1.94-5.00), and eGFRcr (2.34; 1.44-3.79) was associated with increased mortality risk. However, the eGFR 60-90 category was associated with increased mortality risk for eGFRcys (1.80; 1.28-2.53) and eGFRcr-cys (1.91; 1.38-2.66) but not eGFRcr (1.20; 0.85-1.67). The overall NRI for mortality was 26% when reclassifying from eGFRcr to eGFRcys (P < 0.001) and was 20% when reclassifying from eGFRcr to eGFRcr-cys (P < 0.001).
  
  
  CONCLUSIONS
  The addition of cystatin C may improve mortality risk prediction by stages of kidney function relative to creatinine. CKD risk factors are associated with an overestimate of GFR by serum creatinine relative to cystatin C.
authors.affiliation: aSchool of Medicine bDepartment of Medicine cDepartment of Epidemiology and Biostatistics, San Francisco Veterans Affairs Medical Center, University of California, San Francisco, California dDepartment of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland eSection of Nephrology, Department of Medicine fProgram of Applied Translational Research, Yale University, New Haven, Connecticut gClinical Immunology Research Laboratory, University of California, Los Angeles, California hDepartments of Medicine and of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York iDepartments of Medicine, Stroger Hospital and Rush University, Chicago, Illinois jUniversity of Southern California, Los Angeles, California kDivision of Infectious Diseases, Department of Medicine, SUNY Downstate Medical Center, Brooklyn, New York lGeorgetown University Medical Center, Washington, DC, USA.
authors.forename: Todd H
authors.initials: TH
authors.lastname: Driver
authors.forename: Rebecca
authors.initials: R
authors.lastname: Scherzer
authors.forename: Carmen A
authors.initials: CA
authors.lastname: Peralta
authors.forename: Phyllis C
authors.initials: PC
authors.lastname: Tien
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Estrella
authors.forename: Chirag R
authors.initials: CR
authors.lastname: Parikh
authors.forename: Anthony W
authors.initials: AW
authors.lastname: Butch
authors.forename: Kathryn
authors.initials: K
authors.lastname: Anastos
authors.forename: Mardge H
authors.initials: MH
authors.lastname: Cohen
authors.forename: Marek
authors.initials: M
authors.lastname: Nowicki
authors.forename: Anjali
authors.initials: A
authors.lastname: Sharma
authors.forename: Mary A
authors.initials: MA
authors.lastname: Young
authors.forename: Alison
authors.initials: A
authors.lastname: Abraham
authors.forename: Michael G
authors.initials: MG
authors.lastname: Shlipak
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood*; D002908:Chronic Disease; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy*; D006801:Humans; D007674:Kidney Diseases / Q000175:diagnosis* / Q000401:mortality*; D008875:Middle Aged; D011379:Prognosis; D016019:Survival Analysis
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D003404:Creatinine