Effect of hemodiafiltration and sepsis on chemotaxis of granulocytes and the release of IL-8 and IL-10

Background: Extracorporeal circulation, such as cardiopulmonary bypass and hemodialysis, has been associated with an activation of the immune system. Continuous veno venous hemodiafiltration (CVVHD) is used in critically ill septic patients. During CVVHD, cytokines are excreted in ultrafiltrate. When the membranes, used in CVVHD, are incubated with leukocytes in vitro a slight production of cytokines is observed. Due to the underlying disease it is difficult to investigate the effect of CVVHD in septic patients. We therefore studied the separate effect of CVVHD on the chemotaxis of granulocytes, the proliferation of lymphocytes and the release of IL‐8 and IL‐10 in healthy pigs compared to an endotoxin and a control group. Methods: Thirty‐one pigs were anesthetized and mechanically ventilated. CVVHD was performed in 10 pigs. Eleven pigs received an infusion of Escherichia coli endotoxin 30 µg/kg, and 10 pigs served as a control group. The chemotaxis of granulocytes was measured in an assay chamber, and the cytokines IL‐8 and IL‐10 with an enzyme‐linked immunosorbent assay. The adhesion molecules CD18 and CD62 on lymphocytes were measured using monoclonal antibodies, and the lymphocyte proliferation was measured without stimulation and in response to mitogens. Results: CVVHD was accompanied by lymphocytopenia and increased spontaneous lymphoproliferative response, but no change in adhesion molecules on lymphocytes or cytokine levels in plasma, and no decrease in the chemotaxis of granulocytes. Following endotoxin we observed a pronounced lymphocytopenia and an increased secretion of IL‐8 and IL‐10, a decrease in the expression of CD18 on lymphocytes and in the stimulated lymphocyte proliferation and in the chemotaxis of granulocytes. Conclusion: CVVHD does not, in contrast to endotoxin‐induced sepsis, influence chemotaxis of granulocytes, the production of IL‐8 and IL‐10 or the proliferation of lymphocytes.