IS THERE ANY ASSOCIATION BETWEEN SECRETORY I gA AND LACTOFERRIN CONCENTRATION IN MATURE HUMAN MILK AND FOOD ALLERGY IN BREASTFED CHILDREN?* CZY ISTNIEJE ZWIĄZEK POMIĘDZY STĘŻENIEM WYDZIELNICZEJ IMMUNOGLOBULINY A I LAKTOFERYNY W DOJRZAŁYM MLEKU LUDZKIM A WYSTĄPIENIEM ALERGII POKARMOWEJ U DZIECI KARMIONYCH PIERSIĄ?

Background: Breastfeeding is recommended as a protective method against the development of allergy. However, some studies have reported an increased risk of allergies development in breastfed infants of atopic mothers, which implies that atopic mothers may have an altered composition of breast milk. Aim: The aim of the study was to determine the concentration of secretory immunoglobulin A (S-IgA) and lactoferrin in human mature milk and to evaluate the association between the levels of these proteins in breast milk with food allergy in children, depending on the allergy status of the breastfeeding mother. Material and methods: Medical data was collected from birth to 24 months of age from 84 motherchild pairs participating in an EU-funded project “EuroPrevall − The prevalence, cost and basis of food allergy across Europe”. The diagnosis of food allergy in children was based on the positive result of a double-blind placebo-controlled food challenge (DBPCFC). S-IgA and lactoferrin levels were measured in the whey of mature breast milk with commercial enzymelinked immunosorbent assay (ELISA) kits. Statistical analysis (the U Mann-Whitney and Kruskal-Wallis tests as well as the Spearman’s rank correlation coe"cient) was performed using STATISTICA 8.0 PL (Statsoft, Tulsa, USA). Results: Ten out of eighty four participating children had positive skin prick tests (SPT) and/or sIgE to food antigens and in 7 (8.4%) DBPCFC con#rmed food allergy. The median concentration of S-IgA was 476,83 $g/ml (range 6.51-1359.61 $g/ml). The median concentration of Lf was 15.68 $g/ml (range 11.68-36.43 $g/ml). The concentrations of S-IgA and Lf showed a moderate, negative, correlation R=-0.28; p=0.05. Conclusions: Mature breast milk of mothers of children with food allergy and of healthy children showed similar concentrations of both proteins. The level of S-IgA in the mature milk of mothers with atopic allergy was signi#cantly lower, compared to non-atopic mothers. More studies are needed to reveal the mystery of the lack of protective e&ect of breastfeeding on allergy development in children.