Relationships between plasma cytokine concentrations and leukocyte functional antigen expression in patients with sepsis.

To determine the relationships between cytokine concentrations and alterations in leukocyte functional antigen expression in sepsis. Prospective, cross-sectional study. Respiratory, coronary, and medical intensive care units in a university hospital. Forty subjects consisting of: a) patients with severe sepsis, b) patients with sepsis, c) critically ill nonseptic patients, and d) normal controls. None. Plasma concentrations of interleukin (IL)-1 beta, IL-6, IL-8, IL-10, interleukin-1 receptor antagonist (IL-1Ra), and tumor necrosis factor (TNF)-alpha were determined by enzyme-linked immunosorbent assay (ELISA). Peripheral blood monocyte HLA-DR and CD14 expression and neutrophil CD11b expression were determined by flow cytometry. Measurements were taken within 24 hrs of admission to the intensive care unit and/or clinical presentation. Significantly increased plasma IL-6, IL-8, IL-10, and TNF-alpha concentrations were observed in the severe sepsis group compared to normal controls. Increases in IL-1Ra were not significant. Monocyte HLA-DR expression, significantly decreased in patients with severe sepsis, was correlated both with IL-6 (p < .005) and IL-8 concentrations (p < .001). Both of these cytokines had close correlations to Acute Physiology and Chronic Health Evaluation (APACHE) II scores which were also correlated with monocyte HLA-DR. Neutrophil CD11b, which was increased in all infected patients, was significantly correlated with the ratio between IL-1 and IL-1Ra concentrations (p < .001). The percent of CD14+ monocytes was lowest in patients with severe sepsis and showed a significant covariate effect from IL-8 concentrations (p < .001). These findings suggest that the expression of specific functional molecules on peripheral blood leukocytes is variably related to the net production of certain monokines in sepsis.