Breast milk cytokine and IgA composition differ in Estonian and Swedish mothers-relationship to microbial pressure and infant allergy.

The immune system of the neonate is influenced by maternal immunity during pregnancy and lactation. An altered microbial exposure, possibly underlying the increase of allergic diseases in affluent societies, may affect maternal breast milk immune composition. Secretory IgA (SIgA), IL-4, IL-10, IL-13, IFN-[gamma], TGF-[beta]1, and TGF-[beta]2 were analyzed with ELISA in colostrum and 1-mo mature milk from mothers from Estonia (n = 39) and Sweden (n = 60), the two geographically adjacent countries with different living conditions and allergy incidence. The IL-10 and IFN-[gamma] levels were higher in colostrum from Estonian than Swedish mothers, whereas the opposite was true for TGF-[beta]2. In mature milk, higher SIgA and IFN-[gamma] levels but lower TGF-[beta]1 and TGF-[beta]2 levels were observed in Estonian than Swedish mothers. Interestingly, in Sweden but not Estonia, the TGF-[beta]1 and TGF-[beta]2 levels correlated inversely with environmental endotoxin concentrations, whereas positive correlations to microbial load were observed for IL-4, IL-10, and IFN-[gamma]. High colostral IL-13 levels were associated with allergic sensitization during infancy in Sweden. In conclusion, Estonian mothers have lower breast milk levels of TGF-[beta], particularly TGF-[beta]2, but higher levels of SIgA, IL-10, and IFN-[gamma] than Swedish mothers, possibly because of differences in microbial load.

Dysregulated Th1 and Th2 responses in food-allergic children--does elimination diet contribute to the dysregulation?

Infants with eczema and sensitization to foods are recommended skin care and, if food allergy is proven, an elimination diet. Although most of these children tolerate foods before 3 yr of age, some children experience prolonged food allergy. To our knowledge, no prospective study has investigated the cytokine profile in food-sensitized eczematous children with prolonged food intolerance. The aim of the study was to prospectively investigate the development of cytokine production induced by food allergen in food-sensitized eczematous children who, at 4(1/2) yr of age, were allergic or tolerant to egg or milk. Twenty-one eczematous infants, [age 5 (3-10) months; median and range], sensitized to egg and/or milk were included, put on elimination diet and followed prospectively. At 4(1/2) yr of age, the children were defined as tolerant or allergic to egg and/or milk based on open or double-blind placebo-controlled food challenges. Peripheral blood mononuclear cells (PBMC) were isolated from the children on inclusion, after 6 wk of elimination diet, and at 3 and 4(1/2) yr of age. Ovalbumin, beta-lactoglobulin and tetanus toxoid-induced IL-4, -5, -10, -13 and IFN-gamma production from PBMC were analyzed with enzyme-linked immunosorbent assay. The IFN-gamma and IL-5 secretion induced by food allergen at 4(1/2) yr was higher in cell cultures from children who were allergic to egg or milk than in tolerant children. In food-allergic children, the levels of IFN-gamma and IL-5 were higher at 4(1/2) yr compared with inclusion levels, but this increase was generally not observed in the tolerant children who consumed milk and egg. In conclusion, immune cells from food-allergic children on an elimination diet respond with up-regulated T helper 1 and T helper 2 cytokine secretion induced by food allergen. We hypothesize that allergen elimination may influence the regulatory mechanisms maintaining balanced immune responses to innocuous food antigens.

High levels of IgG4 antibodies to foods during infancy are associated with tolerance to corresponding foods later in life.

Children with eczema and sensitization to foods are recommended skin care and, if food allergy is proven by challenge, an elimination diet. For most children the diet period is transient, but the process behind tolerance development and the influence of decreased allergen exposure is not fully known. The aim of the study was to investigate the effect of elimination diet on serum and salivary antibodies and to identify immunological parameters related to the ability to tolerate foods. Eighty-nine children, below 2 yr of age, with eczema and suspected food allergy were included. Recommended treatment was skin care to all children, and 60 children had a period of elimination diet. At 4(1/2) yr of age, the children were divided into two groups, based on if they had been able to introduce the eliminated foods, or not. Serum and salivary antibodies were analyzed with enzyme-linked immunosorbent assay and UniCAP before and after a 6-wk treatment period and at 4(1/2) yr of age. Children sensitized to egg and/or milk that could eat and drink the offending foods at 4(1/2) yr of age, had higher levels of Immunoglobulin G(4) antibodies to ovalbumin and beta-lactoglobulin and also higher IgG(4)/Immunoglobulin E ratios on inclusion in the study, than those who had to eliminate egg and/or milk from their diet, beyond 4(1/2) yr of age. The highest IgG(4)/IgE ratios were found in children with circulating IgE antibodies to egg and/or milk but negative skin prick test on inclusion. The 6-wk treatment period did not significantly affect the levels of serum and salivary antibodies. In conclusion, eczematous, food sensitized infants with high levels of IgG(4) and high ratios of IgG(4)/IgE antibodies to food allergens are more likely to consume these foods at 4(1/2) yr than infants with low levels and ratios.

Fish oil supplementation in pregnancy and lactation may decrease the risk of infant allergy.

UNLABELLED: Maternal intake of omega-3 (omega-3) polyunsaturated fatty acids (PUFAs) during pregnancy has decreased, possibly contributing to a current increased risk of childhood allergy. AIM: To describe the effects of maternal omega-3 long-chain PUFA supplementation during pregnancy and lactation on the incidence of allergic disease in infancy. METHODS: One hundred and forty-five pregnant women, affected by allergy themselves or having a husband or previous child with allergies, were included in a randomized placebo-controlled trial. Daily maternal supplementation with either 1.6 g eicosapentaenoic acid and 1.1 g docosahexaenoic acid or placebo was given from the 25(th) gestational week to average 3-4 months of breastfeeding. Skin prick tests, detection of circulating specific immunoglobulin E (IgE) antibodies and clinical examinations of the infants were performed. RESULTS: The period prevalence of food allergy was lower in the omega-3 group (1/52, 2%) compared to the placebo group (10/65, 15%, p < 0.05) as well as the incidence of IgE-associated eczema (omega-3 group: 4/52, 8%; placebo group: 15/63, 24%, p < 0.05). CONCLUSION: Maternal omega-3 fatty acid supplementation may decrease the risk of food allergy and IgE-associated eczema during the first year of life in infants with a family history of allergic disease.

Low breast milk TGF-beta2 is induced by Lactobacillus reuteri supplementation and associates with reduced risk of sensitization during infancy.

The immunological composition of breast milk differs between mothers. The reasons for these differences and the consequences for the breast-fed infants are poorly understood. The aim of this study was to evaluate the effect of probiotic Lactobacillus reuteri supplementation on the immunological composition of breast milk in relation to sensitization and eczema in the babies. Total IgA, secretory IgA (SIgA), TGF-beta1, TGF-beta2, IL-10, TNF, soluble CD14 (sCD14), and Na/K ratios were analyzed in colostrum and mature milk obtained from women treated with L. reuteri (n = 54) or placebo (n = 55) from gestational week 36 until delivery. Bacteriological analyses of L. reuteri were performed in faecal samples of the mothers. The infants were followed prospectively for 2 yr regarding development of eczema and sensitization as defined by a positive skin prick test and/or circulating allergen-specific IgE antibodies at 6, 12, and 24 months of age. Supplementation of L. reuteri during pregnancy was associated with low levels of TGF-beta2 and slightly increased levels of IL-10 in colostrum. For TGF-beta2, this association was most pronounced in mothers with detectable L. reuteri in faeces. Infants receiving breast milk with low levels of TGF-beta2 were less likely to become sensitized during their first 2 yr of life. A similar trend was observed for development of IgE-associated eczema. The levels of total IgA, SIgA, TGF-beta1, TNF, sCD14, and Na/K ratios in breast milk were not affected by the intake of L. reuteri. None of these parameters correlated with sensitization or development of eczema in the infant, except for high Na/K ratios that associated with increased risk of sensitization. Supplementation with L. reuteri during late pregnancy reduces breast milk levels of TGF-beta2, and low levels of this cytokine are associated with less sensitization and possibly less IgE-associated eczema in breast-fed infants.

Lipopolysaccharide-induced immune responses in relation to the TLR4(Asp299Gly) gene polymorphism.

Altered microbial exposure is a possible explanation for the increase of allergies in the Western world. However, genetic factors influence microbially induced immune responses. We have investigated the TLR4(Asp299Gly) gene polymorphism and its possible association with receptor expression of circulating peripheral blood monocytes and the in vitro cytokine responses and phosphorylation of intracellular signaling proteins in peripheral blood mononuclear cells (PBMC) stimulated with lipopolysaccharide (LPS) from Escherichia coli and Salmonella enterica serotype Typhimurium. We studied 34 of the predominant haplotype TLR4 Asp299 (AA) and 8 heterozygote Asp299Gly (AG) individuals. TLR4 expression levels were similar in the two genotype groups. Serovar Typhimurium LPS induced interleukin-12p70 from PBMC, and the degree of phosphorylation of the intracellular signaling protein IkappaBalpha in PBMC was lower in the AG than the AA group (P=0.03 and P=0.04, respectively). These results were not seen, however, when PMBC were stimulated with E. coli-derived LPS. Based on these results, we propose that TLR4(Asp299Gly) gene polymorphism and the bacterial origin of LPS should be considered when environmental LPS exposure is evaluated in disease risk or protection.

Probiotics in prevention of IgE-associated eczema: a double-blind, randomized, placebo-controlled trial.

BACKGROUND: An altered microbial exposure may underlie the increase of allergic diseases in affluent societies. Probiotics may alleviate and even prevent eczema in infants. OBJECTIVE: To prevent eczema and sensitization in infants with a family history of allergic disease by oral supplementation with the probiotic Lactobacillus reuteri. METHODS: Double-blind, randomized, placebo-controlled trial, which comprised 232 families with allergic disease, of whom 188 completed the study. The mothers received L reuteri ATCC 55730 (1 x 10(8) colony forming units) daily from gestational week 36 until delivery. Their babies then continued with the same product from birth until 12 months of age and were followed up for another year. Primary outcome was allergic disease, with or without positive skin prick test or circulating IgE to food allergens. RESULTS: The cumulative incidence of eczema was similar, 36% in the treated versus 34% in the placebo group. The L reuteri group had less IgE-associated eczema during the second year, 8% versus 20% (P = .02), however. Skin prick test reactivity was also less common in the treated than in the placebo group, significantly so for infants with mothers with allergies, 14% versus 31% (P = .02). Wheeze and other potentially allergic diseases were not affected. CONCLUSION: Although a preventive effect of probiotics on infant eczema was not confirmed, the treated infants had less IgE-associated eczema at 2 years of age and therefore possibly run a reduced risk to develop later respiratory allergic disease. CLINICAL IMPLICATION: Probiotics may reduce the incidence of IgE-associated eczema in infancy.

Significant improvement of eczema with skin care and food elimination in small children.

AIM: To evaluate common methods of investigation and treatment in children younger than 2 y of age with eczema, with or without sensitization to food allergens. METHODS: One hundred and twenty-three children younger than 2 y of age with eczema and suspected food allergy were included in this prospective study. The children underwent skin-prick test with cow's milk, fresh hen's egg white and wheat. Specific IgE to milk and egg white was analysed. The eczema extent and severity was estimated with SCORAD before and after treatment. Children with a positive skin-prick test were instructed to exclude that food item from their diet. All children were treated with emollients and topical steroids when needed. RESULTS: Sixty-two of the children were skin-prick positive to at least one of the allergens; 62% had mild, 30% moderate and 8% severe eczema at their first visit. After treatment, 90% had mild, 10% moderate and 0% severe eczema. Forty-six per cent of the children had circulating IgE antibodies to milk or egg white. Ten per cent had specific IgE but negative skin-prick test to the same allergen. This subgroup improved their eczema significantly without elimination diet. CONCLUSION: The conventional treatments for children with eczema, i.e. skin care and food elimination, are effective. The beneficial effect of skin care as the first step should not be neglected, and it may not be necessary to eliminate food allergens to relieve skin symptoms in all food-sensitized children with eczema.