Role of maternal elimination diets and human milk IgA in the development of cow's milk allergy in the infants

Abstract

Background The role of maternal avoidance diets in the prevention of food allergies is currently under debate. Little is known regarding the effects of such diets on human milk (HM) composition or induction of infant humoral responses. Objective To assess the association of maternal cow’s milk (CM) avoidance during breastfeeding with specific IgA levels in HM and development of cow’s milk allergy (CMA) in infants. Methods We utilized HM and infant serum samples from a prospective birth cohort of 145 dyads. Maternal serum and HM samples were assessed for casein and beta-lactoglobulin (BLG)-specific IgA and IgG by ELISA; 21 mothers prophylactically initiated a strict maternal CM avoidance diet due to a sibling’s history of food allergy and 16 due to atopic eczema or regurgitation/vomiting seen in their infants within the first 3 months of life. Infants’ sera were assessed for casein and BLG-specific IgG, IgA and IgE; CMA was confirmed by an oral food challenge. The impact of HM on BLG uptake was assessed in transcytosis assays utilizing Caco-2 intestinal epithelial cell line. Results Mothers avoiding CM had lower casein- and BLG-specific IgA in HM than mothers with no CM restriction (p=0.019 and p=0.047). Their infants had lower serum casein- and BLG-specific IgG1 (p=0.025 and p<0.001) and BLG-specific IgG4 levels (p=0.037) and their casein- and BLG-specific IgA levels were less often detectable than those with no CM elimination diet (p=0.003 and p=0.007). Lower CM-specific IgG4 and IgA levels in turn were associated with infant CMA. Transcytosis of BLG was impaired by HM with high, but not low levels of specific IgA. Conclusions Maternal CM avoidance was associated with lower levels of mucosal specific IgA levels and development of CMA in infants. Clinical relevance HM IgA may play a role in preventing excessive, uncontrolled food antigen uptake in the gut lumen and thereby in the prevention of CMA.

Mechanisms of Tolerance Induction

“…Presence of food allergens in breast milk might trigger sensitization in the infant [40,41] . For many years, guidelines have recommended avoidance of peanut and tree nuts for the first 3 years of life and some also included avoidance during pregnancy (AAP Committee on Nutrition, 2000).…”

“…In a mouse model, mice exposed to nanograms of egg ovalbumin antigen through breast milk were protected from ovalbumin-induced allergic airway disease and TGF-β from breast milk was critical for tolerance induction, suggesting that variability in breast milk allergen content, TGF-β, and allergen-specific immunoglobulin may contribute to heterogeneity of results on allergy prevention by breastfeeding. Presence of peanut in maternal diet was associated with a reduced risk of food allergy in the offspring in both humans and mice [41,45,57] . Collectively, there is currently no conclusive evidence that breastfeeding protects from development of food allergy, potentially reflecting the environmental factors that affect the composition of maternal milk.…”

Prevention of Allergy: From Immunology of Pregnancy To Infant Feeding in the First Months of Life

“…Авторы исследования отмечают, что в грудном молоке у матерей, получавших безмолочную диету, наблюдались статистически значимо более низкие уровни иммуноглобу-лина A, специфичного к бета-лактоглобулину и казеинам, по сравнению с матерями, в рационе которых молочные продукты были сохранены. Схожие низкие уровни антител класса G в отношении бета-лактоглобулина и казеинов отмечались и в сыворотке крови у их детей, и эти низкие показатели имели положительную корреляцию с частотой развития аллергии к белкам коровьего молока [9]. Эти данные подтверждают отмеченные выше рекомендации о нецелесообразности назначения строгих ограничитель-ных гипоаллергенных диет как здоровым беременным, так и здоровым кормящим женщинам.…”

General Characteristics of Human Neonate Immunity

“…Meanwhile, colostrum and breast milk contain a variety of molecules including the most abundant sIgA which can influence immune responses in the gut-associated lymphoid tissue of neonates [93]. The low level of both cow-milkspecific and total IgA in colostrum or breast milk is associated with increased risk of CMA development [94].…”