title: High levels of soluble tumor necrosis factor receptors 1 and 2 and their association with mortality in patients undergoing hemodialysis.
abstract: OBJECTIVE
  Circulating soluble tumor necrosis factor receptors 1 and 2 (sTNFR1 and sTNFR2) are associated with chronic kidney disease (CKD) progression in patients with CKD or diabetes, and with higher mortality. However, data in patients with end-stage renal disease are scarce. Therefore, we analyzed serum levels of sTNFR1 and sTNFR2 and investigated their association with inflammatory markers and mortality in dialysis patients.
  
  
  METHODS
  This was a longitudinal cohort study of 207 prevalent patients (median age 66 years, 56% men) undergoing hemodialysis in Stockholm, Sweden. Demographics, clinical characteristics, including comorbidities and laboratory data, were obtained at baseline, together with prospective follow-up for mortality.
  
  
  RESULTS
  The median sTNFR1 and sTNFR2 levels were 17,680 ng/l [95% confidence interval (CI) 17,023-18,337] and 24,450 ng/l (95% CI 23,721-25,179), respectively. During a follow-up of 31 months (interquartile range, 21-38), 77 patients died. There was no association between the levels of sTNFRs and mortality in Cox regression models, and no consistent trend towards higher or lower mortality was seen in Laplace regression models. sTNFR1 and sTNFR2 levels were highly associated with other inflammatory markers including interleukin-6, pentraxin 3 and TNF-α.
  
  
  CONCLUSIONS
  Prevalent hemodialysis patients have several-fold higher levels of sTNFRs compared to previous studies in CKD stage 4 patients. As no consistent association between TNFR and mortality was observed, clinical implications of measuring these receptors to predict outcome end-stage renal disease patients provide limited results.
authors.affiliation: Centre for Family Medicine, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Huddinge, Sweden ; Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
authors.forename: Axel C
authors.initials: AC
authors.lastname: Carlsson
authors.affiliation: Department of Clinical Science, Intervention and Technology, Stockholm, Sweden.
authors.forename: Juan-Jesús
authors.initials: JJ
authors.lastname: Carrero
authors.affiliation: Department of Clinical Science, Intervention and Technology, Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Stenvinkel
authors.affiliation: Division of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Matteo
authors.initials: M
authors.lastname: Bottai
authors.affiliation: Department of Clinical Science, Intervention and Technology, Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Barany
authors.affiliation: Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Larsson
authors.affiliation: Department of Medical Sciences, Molecular Epidemiology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden ; School of Health and Social Studies, Dalarna University, Falun, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Ärnlöv
keywords: Inflammation; Laplace regression; Mortality; Tumor necrosis factor