title: Assessment of immunological status in the critically ill.
abstract: The systemic inflammatory response (SIRS) results from various types of injuries such as severe infection, trauma, ischemia-reperfusion and major surgery including cardiac surgery with cardio-pulmonary bypass. This response involves immune cell activation and a complex network of proinflammatory cytokines, which may induce multiple organ failure when uncontrolled. The monocyte plsys a central role in the response to infection with the release of TNF-alpha, IL-1 beta, and IL-12. In addition, monocytes present antigens to T lymphocytes. An optimal antigen presentation requires the expression of MHC class II HLA-DR on monocytes surface and of costimulatory molecules such as CD54 on monocytes and LFA-1 on lymphocytes. It has become increasingly apparent that the proinflammatory response is balanced by concomitant anti-inflammatory mechanisms that results in monocyte deactivation, characterized by a decrease in HLA-DR expression and the release of anti-inflammatory cytokines such as IL-10. This counterregulatory response, if prolonged or predominant, may predispose the patient to a higher risk of infection. Further studies need to be conducted to precise: i) the intensity of depression of the surface molocule expression assessing monocyte function, such as HLA DR and CD54; ii) the level of IL-10 and IL-12 release in patients with severe sepsis; iii) the immuno-modulating effects of frequently used treatments in these patients with severe sepsis and in surgical patients; iv) the time course of recovery; v) if the monitoring of HLA-DR, CD54, IL-10 and IL-12 will better predict the clinical outcome than clinical parameters.
authors.affiliation: Critical Care Division, Department of Anesthesiology, McGrill University, Montreal, Canada. dpayen1234@aol.com
authors.forename: D
authors.initials: D
authors.lastname: Payen
authors.forename: V
authors.initials: V
authors.lastname: Faivre
authors.forename: A C
authors.initials: AC
authors.lastname: Lukaszewicz
authors.forename: M R
authors.initials: MR
authors.lastname: Losser
mesh_terms: D000210:Acute-Phase Reaction / Q000276:immunology*; D000368:Aged; D016638:Critical Illness; D016207:Cytokines / Q000276:immunology; D005260:Female; D006684:HLA-DR Antigens / Q000276:immunology / Q000378:metabolism; D006801:Humans; D007111:Immunity, Cellular; D007239:Infections / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology
chemical_list: D016207:Cytokines; D006684:HLA-DR Antigens