title: Serum cystatin C is a determinant of paraoxonase activity in hemodialyzed and renal transplanted patients.
abstract: BACKGROUND
  Human paraoxonase-1 (PON1) inhibits LDL-oxidation and atherogenesis, and possesses lactonase activity. Decreased PON1 activity was found in hemodialyzed and renal transplanted patients. Cystatin C plays a protective role in atherosclerosis, and is a new, sensitive marker of renal function. The relationship between these two markers in renal failure has not been investigated.
  
  
  OBJECTIVE
  The goal of this study was to clarify the relationship between PON1 activity, cystatin C and homocysteine in chronic renal failure. We also determined the levels of oxidatively modified LDL (oxLDL) and thiobarbituric acid reactive substances (TBARS) to characterize lipid peroxidation.
  
  
  METHODS
  74 hemodialized (HD), 171 renal transplanted patients (TRX), and 110 healthy controls (C) were involved in the study. PON1 activity and TBARS levels were measured spectrophotometrically. OxLDL level was determined with sandwich ELISA.
  
  
  RESULTS
  There was a negative correlation between PON1 activity and cystatin C level. Homocysteine level correlated negatively with PON1 activity, and positively with cystatin C level. OxLDL and TBARS levels were significantly higher in the HD and TRX groups compared to C.
  
  
  CONCLUSIONS
  Cystatin C may be a good predictive factor not only for homocysteine levels but for the antioxidant status in patients with renal failure and renal transplantation.
authors: First Department of Medicine, University of Debrecen Medical and Health Science Center, Debrecen, Hungary.
authors: Eva
authors: E
authors: Varga
authors: Ildikó
authors: I
authors: Seres
authors: Mariann
authors: M
authors: Harangi
authors: Ferenc
authors: F
authors: Sztanek
authors: László
authors: L
authors: Asztalos
authors: Lajos
authors: L
authors: Lõcsey
authors: Béla
authors: B
authors: Borbás
authors: János
authors: J
authors: Szegedi
authors: István
authors: I
authors: Kárpáti
authors: Gyórgy
authors: G
authors: Paragh
mesh_terms: D043303:Aryldialkylphosphatase / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016030:Kidney Transplantation; D008077:Lipoproteins, LDL / Q000097:blood; D006435:Renal Dialysis; D012680:Sensitivity and Specificity; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D055316:Cystatin C; D008077:Lipoproteins, LDL; D017392:Thiobarbituric Acid Reactive Substances; C099252:oxidized low density lipoprotein; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human