5-15-DIHETE AND LIPOXINS GENERATED BY NEUTROPHILS FROM ENDOGENOUS ARACHIDONIC-ACID AS ASTHMA BIOMARKERS

5-Lipoxygenase (5-LO) activation of human blood polymorphonuclear cell s (PMN) from healthy subjects (HS) and from asthmatic patients (AP) wa s investigated comparing their respective capacities to produce lipoxi ns, 5,15-dihydroxyeicosatetraenoic acid (5,15-diHETE) and leukotrienes , under in vitro stimulation by ionophore A23187. PMN from AP were abl e to generate higher leukotriene levels from endogenous sources than P MN 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 man ner, whereas in the same experimental conditions no detectable amounts of these compounds appeared in PMN from HS. The enhanced 5-LO activat ion of blood PMN may reflect transcellular signalisation priming indic ating that lipoxins and 5,15-diHETE could be much more specific inflam matory state biomarkers than leukotriene B-4. (C) 1995 Academic Press, Inc.