title: Does low IgA in human milk predispose the infant to development of cow's milk allergy?
abstract: We sought a relationship between total and cow's milk-specific IgA levels in colostrum and human milk and subsequent development of cow's milk allergy (CMA) in the breast-fed infant. The study included 87 nursing mothers and their infants (age, 2 d to 7 mo), followed prospectively up to 1 y. At 1 y, 48 mothers (69% with an atopic constitution) had an infant with CMA, verified by clinical cow's milk challenge, eight (38% with an atopic constitution) had a baby who had had protracted infantile colic but no CMA (disease control group), and 31 (23% with an atopic constitution) had a healthy infant. Total breast-milk IgA was measured by radial immunodiffusion, and IgA antibodies to cow's milk were measured by ELISA during the breast-feeding period. The levels of total and cow's milk-specific IgA antibodies in colostrum and human milk were significantly lower in the mothers whose baby later developed CMA [estimated third day value, 0.38 g/L (95% confidence interval, 0. 24-0.82)] than in the ones whose infant remained healthy or had had infantile colic but not CMA [0.82 g/L (95% confidence interval, 0. 99-1.51); p < 0.05]. The infants developed CMA significantly more often if the concentration of total IgA antibodies in milk was <0.25 g/L, when measured between 6 d and 4 wk postpartum [sensitivity, 0. 55; specificity, 0.92; odds ratio, 14.7 (95% confidence interval, 3. 1-70.2); p < 0.001]. The levels of cow's milk-specific IgA positively correlated with the levels of total IgA but not with the development of CMA in the infant. The levels of total or cow's milk-specific IgA did not correlate with maternal atopy. IgA antibodies in colostrum and human milk may prevent antigen entry at the intestinal surface of the breast-fed infant. A low IgA content in human milk may lead to defective exclusion of food antigens and thus predispose an offspring to develop food allergies.
authors.affiliation: Department of Dermatology, Helsinki University Central Hospital, FIN-00029 HUCH, Helsinki, Finland.
authors.forename: K M
authors.initials: KM
authors.lastname: Järvinen
authors.forename: S T
authors.initials: ST
authors.lastname: Laine
authors.forename: A L
authors.initials: AL
authors.lastname: Järvenpää
authors.forename: H K
authors.initials: HK
authors.lastname: Suomalainen
mesh_terms: D000818:Animals; D001942:Breast Feeding; D002417:Cattle; D003126:Colostrum / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D005779:Immunodiffusion; D007070:Immunoglobulin A / Q000032:analysis*; D007231:Infant, Newborn; D008892:Milk / Q000276:immunology; D016269:Milk Hypersensitivity / Q000175:diagnosis / Q000276:immunology*; D008895:Milk, Human / Q000276:immunology*; D011446:Prospective Studies; D012882:Skin Tests
chemical_list: D007070:Immunoglobulin A