title: Release of leukotriene B4 and 5-hydroxyeicosatetraenoic acid during phagocytosis of artificial immune complexes by peripheral neutrophils in chronic inflammatory bowel disease.
abstract: The capacity of peripheral neutrophils for activation of the arachidonic acid (AA) metabolism was studied during phagocytosis of IgG containing immune complexes (ICs) binding to Fc-receptors. Release of approximately 9% of the intracellular pool of radiolabelled AA in phospholipids, and release of the pro-inflammatory mediators, leukotriene B4 (LTB4), constituting 1.8%, and 5-hydroxyeicosatetraenoic acid (5-HETE), constituting 2.9% of the total radioactivity released, were demonstrated in 15 patients with untreated Crohn's disease, 15 patients with ulcerative colitis, and in 15 healthy volunteers. The concentrations of LTB4 and 5-HETE released were within the range of chemotactic activity for the two lipoxygenase products. Multiple large IgG containing ICs were revealed in neutrophils after phagocytosis by immunofluorescence. A minor defect in the IC uptake in patients with Crohn's disease observed in the absence of complement only, did not result in a subnormal activation of arachidonic acid release or metabolism. The study suggests that complexes of the IgG-class previously demonstrated in chronic inflammatory bowel disease, particularly in Crohn's disease, may activate inflammatory neutrophils leading to release of significant amounts of the pro-inflammatory lipoxygenase metabolites, LTB4 and 5-HETE.
mesh_terms: D000328:Adult; D000368:Aged; D000936:Antigen-Antibody Complex / Q000276:immunology*; D003093:Colitis, Ulcerative / Q000097:blood* / Q000276:immunology; D003424:Crohn Disease / Q000097:blood* / Q000276:immunology; D005260:Female; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000097:blood*; D007975:Leukotriene B4 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism*; D010587:Phagocytosis
chemical_list: D000936:Antigen-Antibody Complex; D006893:Hydroxyeicosatetraenoic Acids; D007975:Leukotriene B4; C022022:5-hydroxy-6,8,11,14-eicosatetraenoic acid