Background: Eicosanoids are a group of bioactive lipid mediators that have an established pathophysiological role in atopic diseases. However, the role of eicosanoids in early life prior to onset of disease is less well studied.

Objectives: To investigate the association between urinary eicosanoids in early life and development of atopic disease in childhood.

Methods: We measured concentrations of 21 urinary eicosanoids at age 1 year in children from the COPSAC2010cohort (n=450).Clinical data on development of atopic disease were collected prospectively, including wheeze, asthma, atopic dermatitis, and allergic rhinitis until 10 years of age.

Results:Confounderadjusted models showed higher concentrations of thromboxane metabolites at age 1 year were associated with increased risk of concurrent recurrent wheeze (cases=43, aOR=2.05 [1.11-4.02], p=0.03) and concurrent atopic dermatitis (cases=51, aOR=2.24 [1.38-3.67], p=0.001).Higher thromboxane concentrations were also associated with increased risk of developing atopic dermatitis at age 1-10 years(repeated measurement (GEE) aOR=1.72 [1.15-2.56], p=0.0007). Higher concentrations of PGDs (GEE aOR=1.65 [1.1-2.48], p=0.01), lower PGFs (GEE aOR=0.67 [0.44-1], p=0.05) and isoprostanes concentrations (GEE aOR=0.66 [0.44-0.99], p=0.047) were associated with increased risk of asthma at age 1-10 years. Further, higher thromboxane concentrations were positively associated with type 2 inflammation biomarkers including FeNO,blood eosinophils and allergic sensitization.

Conclusions: This exploratory study suggests that early life perturbations in urinary eicosanoids herald the onset of atopic disease in childhood.