PURPOSE: 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.
Written by:
Lezaic V, Dajak M, Radivojevic D, Ristic S, Marinkovic J. Are you the author?
Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
Reference: Int Urol Nephrol. 2013 Dec 14. Epub ahead of print.
doi: 10.1007/s11255-013-0624-7
PubMed Abstract
PMID: 24338493
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