title: An intradialytic increase in serum interleukin-6 levels is associated with an increased mortality in hemodialysis patients.
abstract: BACKGROUND
  The inflammatory marker interleukin-6 (IL-6) increases early in the inflammatory cascade. The aim of this study was to evaluate whether an increase in serum IL-6 levels during a hemodialysis (HD) session is associated with mortality.
  
  
  METHODS
  57 adult patients treated with HD for more than 1 month were prospectively studied over a 3-year follow-up period. Demographic and clinical data were collected and blood samples were drawn before and after a midweek HD session. Events of death and censoring were recorded.
  
  
  RESULTS
  During the 3-year follow-up, 50.8% of the patients died. In univariate Cox regression analysis, an increase in IL-6 levels during HD was associated with an increased mortality (HR 1.41 per pg/ml; 95% CI 1.06 to 1.88; P = .017). In multivariate Cox models, the only independent predictors of all-cause mortality were: an increase in IL-6 levels during dialysis (HR 1.46 per pg/ml; 95% CI 1.08 to 1.98; P = .014), higher baseline C-reactive protein (CRP) levels and older age. When predictors of an increase in serum IL-6 levels during HD were introduced into the model, mortality was still significantly associated with IL-6 elevation during dialysis (HR 1.47 per pg/ml, 95% CI 1.01 to 2.14; P = .045).
  
  
  CONCLUSIONS
  A rise in serum IL-6 levels during a single HD session is associated with a higher mortality among HD patients, independent of predialysis CRP or IL-6 levels. The results may imply the presence of an intradialytic inflammatory response that affects survival in HD patients.
authors.affiliation: Department of Nephrology and Hypertension, Rabin Medical Center, Petah Tikva - Israel.
authors.forename: Shelly
authors.initials: S
authors.lastname: Lichtenberg
authors.forename: Asher
authors.initials: A
authors.lastname: Korzets
authors.forename: Boris
authors.initials: B
authors.lastname: Zingerman
authors.forename: Hefziba
authors.initials: H
authors.lastname: Green
authors.forename: Arie
authors.initials: A
authors.lastname: Erman
authors.forename: Uzi
authors.initials: U
authors.lastname: Gafter
authors.forename: Benaya
authors.initials: B
authors.lastname: Rozen-Zvi
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000401:mortality / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D006435:Renal Dialysis / Q000401:mortality*; D015996:Survival Rate
chemical_list: D015415:Biomarkers; C508600:IL6 protein, human; D015850:Interleukin-6