title: Relationship of Changes in Cystatin-C With Serum Creatinine and Estimated Glomerular Filtration Rate in Kidney Transplantation.
abstract: BACKGROUND
  Serum creatinine (S-Cr) is the most commonly used marker for the assessment of renal function in kidney transplantation (KTx). Cystatin-C (Cys-C) has been proposed as an alternative marker of renal function for the estimated glomerular filtration rate (eGFR), which seems to be more accurate than S-Cr. The aim of this study was to investigate the relationship between changes in S-Cr, Cys-C, and eGFR measurements in KT patients during the early post-transplantation (post-Tx) period.
  
  
  METHODS
  Fifty consecutive patients, aged 15 to 70 years, were subjected to KT. Blood samples were collected at stable time-points on pre-Tx and post-Tx days 2, 6, and 14 and in the third month. Cys-C and S-Cr levels were measured, and GFR was estimated at all time-points using the Cockcroft-Gault and Le Bricon equations.
  
  
  RESULTS
  S-Cr and Cys-C levels decreased significantly post-Tx in all time-point determinations compared with pre-Tx levels. Both markers showed a parallel decrease, reaching normal levels in the third month. Estimated GFR post-Tx by S-Cr and Cys-C exhibited a parallel progressive increase without significant difference between the calculations. Correlation between S-Cr and Cys-C in all time-point determinations was positive and of high significance using Pearson's correlation (r = 0.969, P < .01; r = 0.951, P < .01; r = 0.969, P < .01; r = 0.701, P < .01). Also, the correlation between the eGFR by Cys-C and S-Cr was positive and of high significance in all post-Tx calculations (r = 0.896, P < .01; r = 0.935, P < .01; r = 0.929, P < .01; r = 0.861, P < .01). Ten recipients had acute rejection and were treated successfully with antirejection therapy. Their S-Cr, cys-C, and eGFR results were analyzed separately and showed a significant difference from no-rejection patients, with Cys-C being more sensitive to earlier eGFR changes.
  
  
  CONCLUSIONS
  Cystatin-C is an alternative and accurate marker of renal function in KT patients showing similar diagnostic characteristics to S-Cr. However, Cys-C appears superior to S-Cr in reflecting early GFR temporary changes, which is critical for the early detection of acute rejection.
authors: Iaso Renal Unit, Larisa, Thessalia, Greece. Electronic address: athinagom@yahoo.gr.
authors: A
authors: A
authors: Gompou
authors: Laboratory of Experimental Surgery and Surgical Research N.S. Christeas, Athens School of Medicine, Athens, Greece.
authors: D
authors: D
authors: Perrea
authors: Laboratory of Experimental Surgery and Surgical Research N.S. Christeas, Athens School of Medicine, Athens, Greece; Second Department of Propedeutic Surgery, University of Athens, School of Medicine, Laiko General Hospital, Athens, Greece.
authors: T
authors: T
authors: Karatzas
authors: First Department of Vascular Surgery Clinic, Ygeia Hospital, Marousi, Greece.
authors: J K
authors: JK
authors: Bellos
authors: Department of Informatics, Athens University of Economics and Business, Athens, Greece.
authors: A N
authors: AN
authors: Kastania
authors: Nephrology Department and Transplantation Unit, Laiko General Hospital, Athens, Greece.
authors: I
authors: I
authors: Boletis
authors: IIBEA Biomedical Research Foundation, Academy of Athens, Athens, Greece.
authors: A
authors: A
authors: Kostakis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006084:Graft Rejection / Q000097:blood / Q000503:physiopathology; D006801:Humans; D007677:Kidney Function Tests; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine