Endothelial and leukocyte activation in experimental polytrauma and sepsis.

Vascular endothelial-PMN interactions are critical reactions in the development of organ failure. Both cell types are activated by LPS and proinflammatory cytokines in sepsis. Reactions that are collectively referred to as endothelial activation include expression of procoagulant activity and increased adhesiveness of the endothelium for leukocytes. Some parameters, which are related to endothelial activation are significantly changed during sepsis and altered by anti-TNF therapy (e.g. PAI-1, thrombomodulin), while others (e.g. sELAM) are increased by sepsis but not influenced by anti-TNF therapy. Leukocyte activation (accompanied by elastase release) leads to rearrangement of the CD11/CD18 structures and thereby increased adherence.