Targeted eicosanoids lipidomics of exhaled breath condensate in healthy subjects.
BACKGROUND
Exhaled breath condensate collection is a non-invasive method of sampling the respiratory tract that can be repeated several times in a wide range of clinical settings. Quantitation of non-volatile compounds in the condensate requires highly sensitive analytical methods, e.g. mass spectrometry.


OBJECTIVE
To validate cross-platform measurements of eicosanoids using high performance liquid chromatography or gas chromatography coupled with mass spectrometry in exhaled breath condensate sampled from 58 healthy individuals.


METHODS
Twenty different eicosanoid compounds, representing major arachidonic acid lipoxygenation and cyclooxygenation pathways were measured using a stable isotope dilution method. We applied a free palmitic acid concentration as a surrogate marker for the condensate dilution factor.


RESULTS
Eicosanoids concentrations in the condensates were consistent with their content in other biological fluids. Prostaglandin E(2) was the most abundant mediator, represented by its stable metabolite tetranor-PGEM. Prostaglandin D(2) products were at low concentration, while hydroxyacids derived from lipoxygenation were abundant. 5-HETE was elevated in current tobacco smokers. Leukotriene B(4) has the highest concentration of all 5-LO products. 15-LO analogues of cysteinyl leukotrienes-eoxins were detectable and metabolized to eoxin E(4). Two main vascular prostanoids: prostacyclin and thromboxane B(2) were present as metabolites. A marker for non-enzymatic lipid peroxidation, 8-iso-PGF(2alpha) isoprostane was increased in smokers.


CONCLUSIONS
Presented targeted lipidomics analysis of exhaled breath condensate in healthy subjects justifies its application to investigation of inflammatory lung diseases. Measurements of non-volatile mediators of inflammation in the condensates might characterize disease-specific pathological mechanisms and responses to treatment.
Sanak
Marek
M
Department of Medicine, Jagiellonian University Medical School, Krakow, Poland.
Gielicz
Anna
A
Nagraba
Krzysztof
K
Kaszuba
Marek
M
Kumik
Jagoda
J
Szczeklik
Andrew
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D001944:Breath Tests / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D015777:Eicosanoids / Q000032:analysis* / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D008875:Middle Aged; D025341:Principal Component Analysis; D015203:Reproducibility of Results; D012907:Smoking; D018709:Statistics, Nonparametric
D015777:Eicosanoids