Sepsis and immune response.

BACKGROUND Sepsis and secondary multiple organ failure in critically ill patients are the major cause of death, but the pathogenesis of sepsis is not clear, especially the dysfunction of the immune system. In this paper, we review the response and regulation of the immune system and the functions of a variety of inflammatory mediators in sepsis. DATA SOURCES Studies were identified by searching MEDLINE and PubMed for articles using the keywords "sepsis", "immune response", and "inflammatory mediator" up to October 2010. Additional papers were identified by a manual search of the references from the key articles. RESULTS THIS SYSTEMATIC REVIEW WAS CONDUCTED OF: 1) the immune response; 2) immune regulation; 3) inflammatory mediators; 4) high-mobility group box 1 protein; 5) the complement system; and 6) the autonomic nervous system. There are no therapeutic approaches available for sepsis that target inflammatory response; the mortality of sepsis has not been significantly reduced. CONCLUSIONS Sepsis is complex and dynamic, and it has a group of heterogeneous syndromes. Since different patients with sepsis have different etiology, susceptibility, and responses, treatment should be prescribed individually.