Leukotriene B4 is a pro-inflammatory mediator synthesised in myeloid c
ells from arachidonic acid. Synthesis is catalysed by 5-lipoxygenase a
nd leukotriene A4 hydrolase and is increased by inflammatory mediators
including endotoxin, complement fragments, tumor necrosis factor and
interleukins. A nuclear membrane protein, 5-lipoxygenase activating pr
otein, is an essential co-factor for 5-lipoxygenase. Leukotriene B4 in
duces recruitment and activation of neutrophils, monocytes and eosinop
hils. It also stimulates the production of a number of proinflammatory
cytokines and mediators indicating an ability to augment and prolong
tissue inflammation. Elevated levels of leukotriene B4 have been found
in a number of inflammatory diseases and levels are related to diseas
e activity in some of these. Initial data from pharmacological inhibit
ion studies support a role for leukotriene B4 in the pathogenesis of n
eutrophil mediated tissue damage, and treatments which reduce its prod
uction or block its effects may prove beneficial in neutrophil mediate
d inflammatory diseases. (C) 1998 Elsevier Science Ltd. All rights res
erved.