Hemofiltration and Immune Response in Severe Sepsis 1

BackgroundLevels of pro- and anti-inflammatory cytokines have been determined in numerous investigations. However, measurements of isolated cytokines do not allow conclusions on the resulting immune state. The purpose of this study was to determine resulting immune functions in patients’ plasma. Additionally, similar measurements were performed with ultrafiltrate gained from continuous venovenous hemofiltration (CVVH).Materials and MethodsNine septic patients and six critically ill patients with renal dysfunction in a surgical intensive care unit were observed. Two immune functions were chosen for detailed investigation over a time period of 72 h. The ability of patients’ plasma to induce or suppress β2-integrin expression on neutrophils of healthy controls served as marker for leukocyte activation. Interleukin (IL)-6 production or inhibition in washed whole blood cells induced through patients’ plasma was used as a marker of cytokine secretion.ResultsPlasma from septic patients led to a constantly increased expression of β2-integrins on isolated, unstimulated neutrophils. At the same time, septic plasma permanently suppressed the production of IL-6 and IL-10 in stimulated whole blood. Ultrafiltrate from CVVH mirrors the equivalent immune response patterns found for plasma. We did not find significant differences pre- and postfilter or over the next 72 h in the potential to cause IL-6 and IL-10 production or β2-integrin expression.ConclusionsPlasma from septic patients triggers an increased expression of adhesion molecules and inhibited secretion of IL-6 and IL-10 in stimulated whole blood cells compared with nonseptic critically ill patients. Moreover, CVVH withdraws triggering mediators from plasma in equally bioactive proportions.