Effect of cytokines in breast milk on infant during the first two-years of life

Abstract

Purpose : Breast milk contains several components that provide specific immunity and affect the maturation of the infant's immune system. Allergic disease (AD), including atopic eczema, asthma, allergic rhinitis, and food allergy is characterized by an imbalance between cytokines produced by distinct T-helper cell subtypes. The aim of the study was to investigate the concentrations of cytokines and chemokines that were involved in allergic reactions in breast milk from allergic and nonallergic mothers and then analyse the effect of breastfeeding duration on the prevalence of allergic disease in the age of two. Methods : The breast milk samples were collected from mothers with AD (n=88) and without AD (n=47). Breast milk was collected at the second day (colostrum) and four weeks later (mature milk).The level of Interlukine (IL)-4, IL-5, IL-6, IL-8, IL-10, IL-13, TGF-β1, TGF-β2, RANTES in breast milk were determined by commercially available enzyme-linked immunosorbent assay (ELISA) kits according to the manufacturer's instructions. Results : Mothers with AD had a higher concentration of IL-8 in colostrum compared with those without AD (P=0.021). But, TGF-β1 and TGF-β2 were higher concentrated in colostrum of mother without AD (P=0.013, P=0.001). Whereas concentrations of other cytokines were not significantly different between the two groups. There was no association between levels of cytokines and chemokines in the breast milk and allergic development during the first 2 years of life in the infants. Conclusion : The higher concentration of TGF-β1 and TGF-β2 in colostrum from non-allergic mothers may explain the protective effect. But, the higher concentrations of IL-8 in colostrum from allergic mothers may in part explain the controversial results on the protective effect of breastfeeding against allergic diseases. We conclude that there is no convincing evidence form a relation between cytokines in breast milk and allergic diseases in infants. Longer follow-up are necessary to evaluate the effects of breast milk components on AD.