Rationale

Cord blood eosinophil/basophil progenitor cells (Eo/B) of high risk infants have been shown to predict respiratory illnesses in infancy. Here we investigated this association in a population-based cohort. Furthermore, we analysed whether newborns Th1/Th2 balance and prenatal environmental exposure impact Eo/B recruitment.

Methods

In a sub-cohort of the LINA study cord blood mononuclear cells were used for methylcellulose assays to assess Eo/B differentiation. Questionnaires were recorded during pregnancy and annually thereafter. Volatile organic compounds were measured during pregnancy and cord blood cytokines after ex vivo stimulation.

Results

Cord blood IL-4 and IL-13 positively correlated with Eo/B. Tobacco smoke related benzene was also positively associated with Eo/B. Enhanced Eo/B numbers increased the risk for wheezing within the first 24 months.

Conclusions

The association between cord blood Eo/B and respiratory illnesses is not restricted to high-risk children. Prenatal environmental exposure and a Th2 milieu at birth contribute to Eo/B recruitment.

Abbreviations

• Cb, cord blood;
• CFU, colony forming units;
• Eo/B, eosinophil/basophil;
• ETS, environmental tobacco smoke;
• FHA, family history of atopy;
• GM-CSF, granulocyte macrophage colony-stimulating factor;
• IL-3, IL-5, interleukin 3, interleukin 5;
• IL-5Rα, interleukin 5 receptor alpha sub-unit;
• VOC, volatile organic compounds;
• OR, odds ratio;
• Th2, T helper cell type 2.