Soluble CD14, α-and β-defensins in breast milk: Association with the emergence of allergy in a high-risk population

As innate immunity factors in breast milk (BM) modulate infants’ immune responses, we investigated whether soluble CD14 (sCD14) and defensin levels in BM are associated with the emergence of allergy in childhood. The randomly selected group of 260 mother–child pairs belonged to a randomized, double-blind placebo-controlled trial where 1223 mothers with fetuses at high risk for allergy received for the 4 last wk of pregnancy a mixture of probiotics, or placebo; after birth, the child received the treatment for 6 mo. Children were followed for the emergence of sensitization and allergic symptoms for 5 yr. IgE-mediated allergic disorder was diagnosed in 80 children by the age of 5 yr. Levels of sCD14, human neutrophil peptide (HNP) 1–3 and β-defensin 2 (HBD2) in colostrum and in BM 3 mo post-partum were measured with ELISA. BM sCD14 levels decreased from 0 to 3 mo. HNP1–3 and HBD2 were detected in colostrum, but not in BM 3 mo post-partum. High sCD14 levels in BM 3 mo post-partum were associated with children developing an IgE-mediated allergic disorder by the age of 5 yr. BM HNP1–3, HBD2 or sCD14 levels were not associated with probiotics treatment. Our results suggest that sCD14 in BM influences the emergence of allergy in children with atopic heredity.