Endothelial cells: role in infection and inflammation.

Infection and resulting sepsis continue to be important causes of morbidity and mortality in surgical patients. Although much has been learned about the pathogens and the leukocyte responses to these pathogens, we are only beginning to understand the role of the host in these pathologies. The endothelium is a dynamic participant in cellular and organ function rather than a static barrier as it was once believed. Emerging evidence implicates the endothelium as a central effector in the inflammatory response. Through the expression of surface proteins and secretion of soluble mediators, the endothelium controls vascular tone and permeability, regulates coagulation and thrombosis, and directs the passage of leukocytes into areas of inflammation. Derangements in these normal functions may contribute significantly to a maladaptive inflammatory response leading to systemic inflammation and multiple organ failure.