New research indicates that infants prone to food allergy may display a hyperresponsive innate immune state at birth (Zhang Y et al. Sci Transl Med. 2016;8:321ra8).
In an analysis of 1074 infants in the Barwon Infant Study, Australian researchers discovered an enhanced inflammatory response in the cord blood of infants who later tested positive for food allergies to cow’s milk, egg, peanut, sesame, or cashews at 1 year of age.
Compared with nonallergic infants, those who developed food allergy had more monocytes and fewer natural regulatory T cells (nTregs) in their cord blood. Furthermore, monocytes from food-allergic infants released higher amounts of inflammatory cytokines that decreased the ability of CD4+ T cells to express interleukin 2 in the presence of the mucosal cytokine transforming growth factor β (TGF-β). This environment led to a decrease in the number of activated nTregs and promoted the differentiation of CD4+ T cells and nTregs into an IL-4–secreting nonclassical helper T-cell-2 phenotype associated with inflammation that occurs during allergic reactions.
Hampton T. Hyperactive Innate Immunity at Birth Associated With Food Allergies. JAMA. 2016;315(9):860. doi:10.1001/jama.2016.0915