[Role of polymorphonuclear neutrophils and macrophages in the prevention of postoperative infections].
Polymorphonuclear neutrophils (PMNs) and macrophages are recognized to serve as the first line of defense against bacterial contamination during the perioperative period. Chemoattractants produced by macrophages cause PMN accumulation at the inflammatory site. Proinflammatory cytokines released by macrophages increase adhesion molecule expression on the surface of endothelial cells. P- and E-selectins produce leukocyte rolling, whereas beta 2-integrin-ICAM-1 interaction causes firm adhesion of leukocytes to the endothelium, followed by migration to the interstitium. Thus appropriate activation of the inflammatory cascade leads to leukocyte migration to the infectious focus. In particular, during the first several hours after the onset of bacterial contamination, massive exudation of PMNs is generally observed. PMNs and macrophages phagocytose the bacteria via opsonization and kill them with oxygen products or proteolytic enzymes. Malnutrition and the lack of enteral nutrition are assumed to impair PMN-macrophage-dependent host defense by derangement of adhesion molecule expression and the cytokine milieu. Recently, sticky PMNs before surgery have been reported to increase infectious morbidity after surgery. In addition, augmented alpha 4-integrin-VCAM-1 interaction has been demonstrated during sepsis, which is possibly a mechanism for increased PMN adhesion and resultant organ injury. Further study is needed to clarify the mechanisms of the disturbed function of PMNs and macrophages under various conditions.
Fukatsu
Kazuhiko
K
Division of Basic Traumatology, National Defense Medical College Research Institute, Saitama, Japan.
Hiraide
Hoshio
H
D000818:Animals; D001424:Bacterial Infections / Q000517:prevention & control*; D016207:Cytokines / Q000096:biosynthesis / Q000502:physiology*; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000502:physiology; D008264:Macrophages / Q000502:physiology*; D051379:Mice; D009504:Neutrophils / Q000502:physiology*; D009748:Nutrition Disorders / Q000150:complications / Q000503:physiopathology; D011183:Postoperative Complications / Q000517:prevention & control*
D016207:Cytokines; D018799:Intercellular Adhesion Molecule-1