Effects of different levels of endotoxin contamination on inflammatory cytokine production by peripheral blood mononuclear cells after high-flux hemodialysis.

ABSTRACT

BACKGROUND: In Thailand, dialysate endotoxin contamination levels vary from less than 0.001 to 2.0 EU/ml. This difference has prompted an investigation on the production of proinflammatory cytokines and counter-inflammatory mediators of peripheral blood mononuclear cells (PBMCs) after high-flux dialysis. METHODS: Patients from four hemodialysis (HD) centers who met the inclusion/exclusion criteria were enrolled into the study. PBMCs were isolated by Ficoll density gradient centrifugation and cultured. Supernatants were tested for interleukin 6 (IL-6), IL-1ß and IL-1 receptor antagonist (IL-1Ra) concentration by ELISA. RESULTS: HD centers 1, 2, 3 and 4 had mean dialysate endotoxin contamination levels of 0.001, 0.026, 0.558 and 1.960 EU/ml, respectively. HD center 4 had the highest levels of IL-6 (1,052.3 ± 240.7 pg/10(6) PBMCs), IL-1ß (1,297.1 ± 334.6 pg/10(6) PBMCs) and IL-1Ra (2,713.4 ± 1,255.3 pg/10(6) PBMCs). There were no significant differences in cytokine production between HD centers 1 and 2. CONCLUSION: Our study showed that ultrapure dialysate can minimize the risk of stimulating inflammatory cells. Ultrapure dialysate may prevent or delay endotoxin exposure-related complications.