Immunologic function and survival in hemodialysis patients

Immunologic function and survival in hemodialysis patients. Although the medical determinants of mortality in patients with end-stage renal disease (ESRD) treated with hemodialysis (HD) are well appreciated, the contribution of immunologic parameters to survival in such patients is unclear, especially when variations in age, medical comorbidity and nutrition are controlled. In addition, although dysregulation of cytokine metabolisn has been appreciated in patients with ESRD, the association of these parameters with outcomes has not been established. Recently, the type of dialyzer used in patients’ treatment has been associated with survival, but the mechanisms underlying these findings, including their immune effects, have not been established. We conducted a prospective, cross-sectional, observational multicenter study of urban HD patients to determine the contribution of immunological factors to patient survival. We hypothesized increased proinflammatory cytokines would be associated with increased mortality, and that improved immune function would be associated with survival. Patients were assessed using demographic and anthropometric indices, Kt/V, protein catabolic rate (PCR) and immunologic variables including circulating cytokine [interleukin (IL)-1, IL-2, IL-4, IL-5, IL-6, IL-12, IL-13 and tumor necrosis factor (TNF)-α] levels, total hemolytic complement activity (CH50), and T cell number and function. A severity index, previously demonstrated to be a mortality marker, was used to grade medical comorbidity. A Cox proportional hazards model, controlling for patients’ age, severity index, level of serum albumin concentration, dialyzer type and dialysis site was used to assess relative survival risk. Two hundred and thirty patients entered the study. The mean (±sd) age of the population was 54.4 ± 14.2years, mean serum albumin concentration was 3.86 ± 0.47g/dl, mean PCR was 1.1 ± 0.28g/kg/day, and mean Kt/V 1.2 ± 0.3. Patients’ serum albumin concentration was correlated with levels of Kt/V and PCR, and their circulating IL-13 and TNF-α levels, but negatively with their circulating IL-2 levels, T-cell number and T-cell antigen recall function. T-cell antigen recall function correlated negatively with PCR, but not Kt/V. There was no correlation of any other immune parameter and medical or demographic factor. Immune parameters, however, were all highly intercorrelated. Mean level of circulating cytokines in HD patients were in all cases greater than thos