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.
Research design and 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.
Keywords: Inflammation; Laplace regression; Mortality; Tumor necrosis factor.