Pre- and perinatal characteristics and breast milk immune markers

BACKGROUND: Maternal allergy and gestational exposures can alter the concentration of type-1/type-2/T-regulatory markers in breast milk. We tested whether maternal risk factors are related to breast milk immune markers. METHODS: Expecting mothers were enrolled in 2008-2010 in South Carolina in prenatal clinics and classes. Interferon (IFN)-gamma-induced protein 10 (CXCL10), CCL11, interleukin (IL)-1 beta, IL-4, IL-5, IL-6, CXCL8, IL-10, IL-12(p70), IL-13, transforming growth factor (TGF)-beta 1, and immunoglobulin (Ig)A in 115 whey samples were measured by immunoassays. Maternal asthma, eczema, rhinitis, smoking, urogenital infections during gestation, pet exposure, education, race/ethnicity, age, body mass, and the child's birth date and sex were ascertained. The effects of these risk factors on immune markers were estimated using general linear models. RESULTS: Maternal asthma was linked to higher levels of IL-5, rhinitis to lower levels of IL-5 and INF-gamma, and eczema to lower levels of IL-6. Gestational smoking was related to increased concentrations of CXCL8 and IL-6. African-American mothers had markedly higher levels of IL-6, IFN-gamma, and CXCL8. Urogenital infections, maternal age, body mass, child's sex, and season of birth contributed to the variation. CONCLUSION: The impact of maternal allergies on immune markers in breast milk was small compared with that of maternal nondisease characteristics.