5-15-diHETE and lipoxins generated by neutrophils from endogenous arachidonic acid as asthma biomarkers.

5-Lipoxygenase (5-LO) activation of human blood polymorphonuclear cells (PMN) from healthy subjects (HS) and from asthmatic patients (AP) was investigated comparing their respective capacities to produce lipoxins, 5,15-dihydroxyeicosatetraenoic acid (5,15-diHETE) and leukotrienes, under in vitro stimulation by ionophore A23187. PMN from AP were able to generate higher leukotriene levels from endogenous sources than PMN from HS. Moreover they produced 5,15-diHETE (from 50 to 280ng/10(7) cells) and lipoxins (from 1 to 30ng/10(7) cells), in a linear manner, whereas in the same experimental conditions no detectable amounts of these compounds appeared in PMN from HS. The enhanced 5-LO activation of blood PMN may reflect transcellular signalisation priming indicating that lipoxins and 5,15-diHETE could be much more specific inflammatory state biomarkers than leukotriene B4.