title: Oxidative stress in kidney transplantation: malondialdehyde is an early predictive marker of graft dysfunction.
abstract: BACKGROUND
  Oxidative stress is one of the most important components of the ischemia-reperfusion process after kidney transplantation (KTx) and increases with graft dysfunction.
  
  
  METHODS
  This prospective study was conducted on 40 consecutive KTx recipients to evaluate time-dependent changes in oxidative stress-related parameters within the first week after KTx and to assess their performance in predicting delayed graft function (DGF=dialysis requirement during initial posttransplant week) and graft function at 1 year. Blood samples were collected before (day 0) and after KTx (days 1, 2, 4, and 7). Total antioxidant capacity, plasma levels of malondialdehyde (MDA), and activities of glutathione peroxidase, glutathione reductase and superoxide dismutase were measured. Multivariable linear mixed and linear regression models, receiver-operating characteristic (ROC), and areas under ROC curves (AUC-ROC) were used.
  
  
  RESULTS
  At all time points after KTx, mean MDA levels were significantly higher in patients developing DGF (n=18). Shortly after KTx (8-12 hr), MDA values were higher in DGF recipients (on average, +0.16 μmol/L) and increased further on following day, contrasting with prompt functioning recipients. Day 1 MDA levels accurately predicted DGF (AUC-ROC=0.90), with a performance higher than SCr (AUC-ROC=0.73) and similar to cystatin C (AUC-ROC=0.91). Multivariable analysis revealed that MDA levels on day 7 represented an independent predictor of 1-year graft function. Antioxidant enzyme activities were not significantly changed during the study period and were not predictors of 1-year graft function.
  
  
  CONCLUSIONS
  Increased MDA levels on day 1 after KTx might be an early prognostic indicator of DGF, and levels on day 7 might represent a useful predictor of 1-year graft function.
authors.affiliation: 1 Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António, Porto, Portugal. 2 Unit for Multidisciplinary Investigation in Biomedicine (UMIB), Porto, Portugal. 3 Institute of Public Health (ISPUP), University of Porto, Porto, Portugal. 4 Chemical Chemistry Department, Centro Hospitalar do Porto, Hospital de Santo António, Porto, Portugal. 5 Department of Population Studies, Institute of Biomedical Sciences Abel Salazar (ICBAS) University of Porto, Porto, Portugal. 6 Address for Correspondence: Isabel Fonseca, Nephrology and Kidney Transplantation Department, Centro Hospitalar do Porto, Hospital de Santo António , Largo Prof. Abel Salazar 4099-001 Porto, Portugal.
authors.forename: Isabel
authors.initials: I
authors.lastname: Fonseca
authors.forename: Henrique
authors.initials: H
authors.lastname: Reguengo
authors.forename: Manuela
authors.initials: M
authors.lastname: Almeida
authors.forename: Leonídio
authors.initials: L
authors.lastname: Dias
authors.forename: La Salete
authors.initials: LS
authors.lastname: Martins
authors.forename: Sofia
authors.initials: S
authors.lastname: Pedroso
authors.forename: Josefina
authors.initials: J
authors.lastname: Santos
authors.forename: Luísa
authors.initials: L
authors.lastname: Lobato
authors.forename: António Castro
authors.initials: AC
authors.lastname: Henriques
authors.forename: Denisa
authors.initials: D
authors.lastname: Mendonça
mesh_terms: D015415:Biomarkers / Q000097:blood; D051799:Delayed Graft Function / Q000097:blood*; D005260:Female; D005500:Follow-Up Studies; D006085:Graft Survival / Q000502:physiology*; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008315:Malondialdehyde / Q000097:blood*; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D011446:Prospective Studies; D012372:ROC Curve; D013997:Time Factors
chemical_list: D015415:Biomarkers; D008315:Malondialdehyde