Urinary LTE4 may be associated with TH2-driven asthma: Initial data from the Pan-European U-BIOPRED IMI project

Background: We tested if lipid mediator profiles could be used as biomarkers of certain phenotypes of asthma and measured the urinary concentrations of metabolites of the cysteinyl-leukotrienes (CysLTs), prostaglandins (PGs) and isoprostanes (IPs) at the cross-sectional baseline visit in the U-BIOPRED study of adults with asthma. Methods: Subjects (aged 18-79) with severe asthma (SA; n=231), mild-to-moderate asthma (MA; n=71) and healthy controls (HC; n=72) provided spot urine samples that were analysed using UPLC-MS/MS (Balgoma et al Anal Chem 2013). Results: The urinary excretion of all lipid mediators, except tetranorPGEM, were highest among SA, and generally higher in MA vs. healthy controls. LTE 4 displayed the highest median fold change (MFC) (MFC=2.1, P 2α (MFC=1.6, P 2α (MFC=1.3, P 4 >and tetranorPGDM. The subjects with the highest 25 th percentile of urinary LTE 4 had a highly significant lower lung function than those in the lowest 25 th percentile (FEV 1 % predicted being 58.9 ± 26.7 vs 106.6 ± 11.3) . Moreover, urinary LTE 4 levels correlated with high total IgE, exhaled NO and eosinophils in sputum or blood. Conclusion: Increased urinary LTE 4 was associated with decreased baseline lung function and suggestive of a Th2 profile of airway inflammation.