title: Glomerular filtration rate estimation in renal transplant patients based on serum cystatin-C levels: comparison with other markers of glomerular filtration rate.
abstract: OBJECTIVE
  The assessment of glomerular filtration rate (GFR) is the most commonly used test of renal function. Cystatin-C, a cysteine protease inhibitor, which can be measured by light-scattering immunoassay, possesses many of the attributes required of the ideal GFR marker. Conversely, many endogenous markers that are widely used for the estimation of GFR such as serum creatinine (SCr) are not ideal. The present study was undertaken to evaluate the clinical application of serum cystatin-C (CysC) as a new marker of GFR in renal transplant patients.
  
  
  METHODS
  Eighteen patients (9 men) were enrolled in the study (mean age: 46.35, range: 31-67 years) to measure serum CysC levels and compare them, with SCr, creatinine clearance (CCr), as well as the Cockcroft-Gault equation (CG) or the MDRD as indicator of GFR. Spearman's correlation coefficient was used to determine the relationship between CysC and other markers.
  
  
  RESULTS
  There was a significant negative correlation between serum CysC and CCr (r = -0.768). Moreover, the CysC level was negatively correlated with CG (r = -0.854), positively correlated with SCr (r = 0.629), and negatively correlated with MDRD (r = -0.604).
  
  
  CONCLUSIONS
  These results indicate that measurement of serum cystatin-C was useful and accurate to estimate GFR in renal transplant patients. The recent literature confirms our data although there are concerns about nonrenal influence on this test. Although serum CysC can generally be recommended as a marker for GFR, our study is still in progress seeking to validate the conclusions in a larger number of patients.
authors.affiliation: Nephrology Department, Papageorgiou General Hospital, Thessaloniki, Greece. giannisgriv@hotmail.com
authors.forename: G
authors.initials: G
authors.lastname: Visvardis
authors.forename: I
authors.initials: I
authors.lastname: Griveas
authors.forename: R
authors.initials: R
authors.lastname: Zilidou
authors.forename: D
authors.initials: D
authors.lastname: Papadopoulou
authors.forename: E
authors.initials: E
authors.lastname: Mitsopoulos
authors.forename: P
authors.initials: P
authors.lastname: Kyriklidou
authors.forename: E
authors.initials: E
authors.lastname: Manou
authors.forename: E
authors.initials: E
authors.lastname: Ginikopoulou
authors.forename: D
authors.initials: D
authors.lastname: Meimaridou
authors.forename: A
authors.initials: A
authors.lastname: Pavlitou
authors.forename: G
authors.initials: G
authors.lastname: Sakellariou
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000378:metabolism; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D016030:Kidney Transplantation / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D003404:Creatinine