Background: Allergen-sensitized pregnant mice have increased plasma levels of the lipids β-glucosylceramides (βGlcCers) that are transplacentally transferred to the fetus, increased subsets of proinflammatory dendritic cells in the fetal liver and pup lung, and increased allergen-induced offspring lung inflammation.
Objective: Our aim was to determine whether these preclinical observations extend to a human association of βGlcCers with wheeze and allergic disease in the prospective Wisconsin Infant Study Cohort.
Methods: We measured 74 lipids in cord blood plasma by using mass spectrometry detection of sphingolipids, eicosanoids, and docosinoids, as well as an ELISA for 13-hydroxyoctadecadienoic acid. Lipid profiles were determined by unbiased Uniform Manifold Approximation and Projection dimensional reduction machine learning. Lipid profiles and a proinflammatory lipid index were analyzed for association with maternal allergy and childhood outcomes of wheeze, atopic dermatitis, cord blood leukocytes, and total IgE level at age 1 year.
Results: Uniform Manifold Approximation and Projection analysis of lipids defined 8 cluster-specific plasma lipid profiles. Cluster 6 had significantly lower levels of plasma βGlcCers and a higher frequency of cord blood plasmacytoid dendritic cells that mediate anti-inflammatory responses, which is consistent with an anti-inflammatory profile. For clusters and for each infant, a proinflammatory lipid index was calculated to reflect the sum of the proinflammatory lipids minus the anti-inflammatory lipids that were significantly different than in cluster 6. The cluster proinflammatory lipid index was associated with cord blood basophil frequency and with wheeze and atopic dermatitis in the first year of life. The infant inflammatory lipid index was associated with increased risk of wheeze in the first year of life.
Conclusion: The cord blood proinflammatory lipid index is associated with early-life atopic dermatitis and wheezing.
Keywords: Allergy; basophils; birth cohort; dendritic cells; lipidomics; maternal; β-glucosylceramide.