Plasma interleukin-18 levels in hemodialysis patients: increased by dialysis process and association with interleukin-6 and tumor necrotic factor-alpha.
This study investigated changes of interleukin-18 (IL-18) levels before and after dialysis, and the possible association with other pro-inflammatory cytokines, such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha). Plasma IL-18 of healthy controls, and pre- and post-dialysis of uremic patients undergoing hemodialysis (HD) were evaluated by ELISA methodology. Plasma IL-18 levels were significantly increased in patients with maintenance HD (p <0.001) compared to its level in normal subjects. When compared to pre-dialysis levels, a significant increase in plasma IL-18 was measured at the end of HD (p = 0.032). There was a significant correlation among plasma IL-18, IL-6 and TNF-alpha levels in HD patients. Plasma IL-18 concentration was significantly higher in HD patients and was significantly elevated by cellulose-based HD processes. Pre-activation of immunologically active cells may contribute to the association between pre-dialysis IL-18 and post-dialysis IL-6 and TNF-alpha levels.