title: Cystatin C and serum creatinine as predictors of kidney graft outcome.
abstract: OBJECTIVE
  Serum cystatin C (Cys C) was evaluated as a predictor of kidney graft failure progression, and its predictive ability was compared to other markers of graft function.
  
  
  METHODS
  The following kidney graft markers were determined in 91 patients who came for regular checkups of kidney graft function to our outpatient service in February 2008: Cys C, serum creatinine (sCr), 24-h proteinuria and 24-h urinary creatinine clearance (CCr). Glomerular filtration rate (eGFR) was estimated using sCr-based and Cys C formula. Patients were regularly monitored until February 2013 or to graft failure.
  
  
  RESULTS
  During follow-up, graft failure occurred in 21 recipients. The Cys C ≥2.65 mg/l discriminated patients with and without graft failure (sensitivity of 80.95% and specificity of 92.86%). According to c statistic, the highest performance was achieved for Cys C (0.874). In addition, Cys C area under the curve (AUC) was significantly better than CCr AUC (p = 0.007), 24-h proteinuria AUC (p = 0.03), eGFR estimated by the chronic kidney disease epidemiology collaboration (EPI) AUC (p = 0.05), but not better than sCr or eGFR AUCs calculated by other formulas. In the multivariable model, sCr, CCr, Cys C and eGFRs were predictors of graft failure. Combination of Cys C, sCr and logarithm of 24 h proteinuria (0.883) or Cys C, CCr and logarithm of 24-h proteinuria (0.884) had the highest AUC for predicting graft outcome that exceed insignificantly Cys C or sCr areas.
  
  
  CONCLUSIONS
  The most reliable predictors of graft outcome were Cys C, sCr and proteinuria. Because Cys C is unavailable in many transplant centers, from the practical point of view, sCr remains the most sensitive predictor of graft outcome.
authors: Faculty of Medicine, University of Belgrade, Belgrade, Serbia, visnjalezaic@gmail.com.
authors: Visnja
authors: V
authors: Lezaic
authors: Marijana
authors: M
authors: Dajak
authors: Dragana
authors: D
authors: Radivojevic
authors: Stojanka
authors: S
authors: Ristic
authors: Jelena
authors: J
authors: Marinkovic
mesh_terms: D000328:Adult; D000419:Albuminuria; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006084:Graft Rejection; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012680:Sensitivity and Specificity
chemical_list: D055316:Cystatin C; D003404:Creatinine