Background The role of dietary factors in the development of allergies is a topic of debate, especially the potential associations between infant feeding practices and allergic diseases. Previously, ...we reported that increased food diversity introduced during the first year of life reduced the risk of atopic dermatitis. Objective In this study we investigated the association between the introduction of food during the first year of life and the development of asthma, allergic rhinitis, food allergy, or atopic sensitization, taking precautions to address reverse causality. We further analyzed the association between food diversity and gene expression of T-cell markers and of Cε germline transcript, reflecting antibody isotype switching to IgE, measured at 6 years of age. Methods Eight hundred fifty-six children who participated in a birth cohort study, Protection Against Allergy Study in Rural Environments/EFRAIM, were included. Feeding practices were reported by parents in monthly diaries during the first year of life. Data on environmental factors and allergic diseases were collected from questionnaires administered from birth up to 6 years of age. Results An increased diversity of complementary food introduced in the first year of life was inversely associated with asthma with a dose-response effect (adjusted odds ratio with each additional food item introduced, 0.74 95% CI, 0.61-0.89). A similar effect was observed for food allergy and food sensitization. Furthermore, increased food diversity was significantly associated with an increased expression of forkhead box protein 3 and a decreased expression of Cε germline transcript. Conclusion An increased diversity of food within the first year of life might have a protective effect on asthma, food allergy, and food sensitization and is associated with increased expression of a marker for regulatory T cells.
Background Hay fever or seasonal allergic rhinitis (AR) is a chronic disorder associated with IgE sensitization to grass. The underlying genetic variants have not been studied comprehensively. There ...is overwhelming evidence that those who have older siblings have less AR, although the mechanism for this remains unclear. Objective We sought to identify common genetic variant associations with prevalent AR and grass sensitization using existing genome-wide association study (GWAS) data and to determine whether genetic variants modify the protective effect of older siblings. Method Approximately 2.2 million genotyped or imputed single nucleotide polymorphisms were investigated in 4 large European adult cohorts for AR (3,933 self-reported cases vs 8,965 control subjects) and grass sensitization (2,315 cases vs 10,032 control subjects). Results Three loci reached genome-wide significance for either phenotype. The HLA variant rs7775228, which cis -regulates HLA-DRB4 , was strongly associated with grass sensitization and weakly with AR ( Pgrass = 1.6 × 10−9 ; PAR = 8.0 × 10−3 ). Variants in a locus near chromosome 11 open reading frame 30 (C11orf30) and leucine-rich repeat containing 32 (LRRC32) , which was previously associated with atopic dermatitis and eczema, were also strongly associated with both phenotypes (rs2155219; Pgrass = 9.4 × 10−9 ; PAR = 3.8 × 10−8 ). The third genome-wide significant variant was rs17513503 (Pgrass = 1.2 × 10−8 ; PAR = 7.4 × 10−7 ) which was located near transmembrane protein 232 (TMEM232) and solute carrier family 25, member 46 ( SLC25A46 ). Twelve further loci with suggestive associations were also identified. Using a candidate gene approach, where we considered variants within 164 genes previously thought to be important, we found variants in 3 further genes that may be of interest: thymic stromal lymphopoietin ( TSLP ), Toll-like receptor 6 ( TLR6 ) and nucleotide-binding oligomerization domain containing 1 ( NOD1/CARD4 ). We found no evidence for variants that modified the effect of birth order on either phenotype. Conclusions This relatively large meta-analysis of GWASs identified few loci associated with AR and grass sensitization. No birth order interaction was identified in the current analyses.
Background Living on a farm has repeatedly been shown to protect children from asthma and allergies. A major factor involved in this effect is consumption of unprocessed cow's milk obtained directly ...from a farm. However, this phenomenon has never been shown in a longitudinal design, and the responsible milk components are still unknown. Objectives We sought to assess the asthma-protective effect of unprocessed cow's milk consumption in a birth cohort and to determine whether the differences in the fatty acid (FA) composition of unprocessed farm milk and industrially processed milk contributed to this effect. Methods The Protection Against Allergy—Study in Rural Environments (PASTURE) study followed 1133 children living in rural areas in 5 European countries from birth to age 6 years. In 934 children milk consumption was assessed by using yearly questionnaires, and samples of the “usually” consumed milk and serum samples of the children were collected at age 4 years. Doctor-diagnosed asthma was parent reported at age 6 years. In a nested case-control study of 35 asthmatic and 49 nonasthmatic children, 42 FAs were quantified in milk samples. Results The risk of asthma at 6 years of age was reduced by previous consumption of unprocessed farm milk compared with shop milk (adjusted odds ratio for consumption at 4 years, 0.26; 95% CI, 0.10-0.67). Part of the effect was explained by the higher fat content of farm milk, particularly the higher levels of ω-3 polyunsaturated FAs (adjusted odds ratio, 0.29; 95% CI, 0.11-0.81). Conclusion Continuous farm milk consumption in childhood protects against asthma at school age partially by means of higher intake of ω-3 polyunsaturated FAs, which are precursors of anti-inflammatory mediators.
Background Recently, the bacterial diversity of the intestinal flora and the diversity of various environmental factors during infancy have been linked to the development of allergies in childhood. ...Food is an important environmental exposure, but the role of food diversity in the development of asthma and allergies in childhood is poorly defined. Objective We studied the associations between food diversity during the first year of life and the development of asthma and allergies by age 5 years. Methods In a Finnish birth cohort we analyzed data on 3142 consecutively born children. We studied food diversity at 3, 4, 6, and 12 months of age. Asthma, wheeze, atopic eczema, and allergic rhinitis were measured by using the International Study of Asthma and Allergies in Childhood questionnaire at age 5 years. Results By 3 and 4 months of age, food diversity was not associated with any of the allergic end points. By 6 months of age, less food diversity was associated with increased risk of allergic rhinitis but not with the other end points. By 12 months of age, less food diversity was associated with increased risk of any asthma, atopic asthma, wheeze, and allergic rhinitis. Conclusion Less food diversity during the first year of life might increase the risk of asthma and allergies in childhood. The mechanisms for this association are unclear, but increased dietary antigen exposure might contribute to this link.
The occupant as a source of house dust bacteria Täubel, Martin, PhD; Rintala, Helena, PhD; Pitkäranta, Miia, MSc ...
Journal of allergy and clinical immunology,
10/2009, Letnik:
124, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Background Markers for microbial groups are commonly measured in house dust samples to assess indoor exposure to microbes in studies on asthma and allergy. However, little is known about the sources ...of different microbes. A better understanding of the nature and origin of microbes present in the immediate environment of human beings is crucial if one wants to elucidate protective as well as adverse effects on human health. Objective To determine the extent to which the bacterial composition of mattress and floor dust reflects the presence of the human body in relation to other environmental sources. Methods House dust and skin surface swab samples of occupants in 4 homes were collected and analyzed for their bacterial content, using a culture-independent methodology. Bacterial sequences analyzed from the different house dusts and skin surface swabs represented random samples of bacteria present in a given sample. Highly similar sequences were grouped to assess biodiversity and to draw conclusions about the sources of bacteria. Results The bacterial flora in the house dust samples was found to be highly diverse and dominated by gram-positive bacteria. To a considerable extent, the presence of different bacterial groups was attributed to human sources. In the individuals' mattress dust samples, 69% to 88% of the bacterial sequences analyzed were associated with human origins. The respective percentages for the individual floor dusts ranged from 45% to 55%. Conclusion Our study indicates that human-derived bacteria account for a large part of the mainly gram-positive bacterial content in house dust.
Background Environmental factors can affect the development of atopic dermatitis, and this was described to be already effective during pregnancy and in early life. An important early postnatal ...exposure is nutrition, although its association with allergic disease remains unclear. Objective We sought to determine prospectively whether early postnatal exposures, such as the introduction to complementary food in the first year of life, are associated with the development of atopic dermatitis, taking into account the reverse causality. Methods One thousand forty-one children who participated in the Protection Against Allergy–Study in Rural Environments birth cohort study were included in the current study. Atopic dermatitis was defined by a doctor's diagnosis reported by the parents of children up to 4 years of age, by questionnaires, and/or by positive SCORAD scores from 1 year of age and according to the age of onset within or after the first year of life. Feeding practices were reported by parents in monthly diaries between the 3rd and 12th months of life. Results The diversity of introduction of complementary food in the first year of life was associated with a reduction in the risk of having atopic dermatitis with onset after the first year of life (adjusted odds ratio for atopic dermatitis with each additional major food item introduced, 0.76; 95% CI, 0.65-0.88). The introduction of yogurt in the first year of life also reduced the risk for atopic dermatitis (adjusted odds ratio, 0.41; 95% CI, 0.23-0.73). Conclusion As early-life exposure, the introduction of yogurt and the diversity of food introduced in the first year of life might have a protective effect against atopic dermatitis.
Background There is evidence that gene expression of innate immunity receptors is upregulated by farming-related exposures. Objective We sought to determine environmental and nutritional exposures ...associated with the gene expression of innate immunity receptors during pregnancy and the first year of a child's life. Methods For the Protection Against Allergy: Study in Rural Environments (PASTURE) birth cohort study, 1133 pregnant women were recruited in rural areas of Austria, Finland, France, Germany, and Switzerland. mRNA expression of the Toll-like receptor (TLR) 1 through TLR9 and CD14 was assessed in blood samples at birth (n = 938) and year 1 (n = 752). Environmental exposures, as assessed by using questionnaires and a diary kept during year 1, and polymorphisms in innate receptor genes were related to gene expression of innate immunity receptors by using ANOVA and multivariate regression analysis. Results Gene expression of innate immunity receptors in cord blood was overall higher in neonates of farmers ( P for multifactorial multivariate ANOVA = .041), significantly so for TLR7 (adjusted geometric means ratio aGMR, 1.15; 95% CI, 1.02-1.30) and TLR8 (aGMR, 1.15; 95% CI, 1.04-1.26). Unboiled farm milk consumption during the first year of life showed the strongest association with mRNA expression at year 1, taking the diversity of other foods introduced during that period into account: TLR4 (aGMR, 1.22; 95% CI, 1.03-1.45), TLR5 (aGMR, 1.19; 95% CI, 1.01-1.41), and TLR6 (aGMR, 1.20; 95% CI, 1.04-1.38). A previously described modification of the association between farm milk consumption and CD14 gene expression by the single nucleotide polymorphism CD14/C-1721T was not found. Conclusion Farming-related exposures, such as raw farm milk consumption, that were previously reported to decrease the risk for allergic outcomes were associated with a change in gene expression of innate immunity receptors in early life.
Atopic sensitization in the first year of life Depner, Martin, PhD; Ege, Markus J., MD; Genuneit, Jon, MD ...
Journal of allergy and clinical immunology,
03/2013, Letnik:
131, Številka:
3
Journal Article
Recenzirano
Odprti dostop
Background There is conflicting evidence on whether allergen-specific memory is primed prenatally, whether this priming affects persistent immunologic effects, and whether it is modulated by the ...first environmental exposures in infancy. Objective We sought to explore the course of atopic sensitization between birth and 12 months of age. Methods Specific IgE levels for 6 food and 13 common inhalant allergens were assessed in cord blood and 1-year blood samples in the Protection against Allergy–Study in Rural Environments (PASTURE) birth cohort including 793 children from rural regions of 5 European countries. Detailed information on children’s health, nutrition, and farm-related exposures was gathered by using a pregnancy questionnaire, 2 questionnaires at 2 and 12 months of age, and a diary covering the time in between. Results Sensitization was more common at 12 months of age than at birth for almost all specificities. On an individual level, persistent sensitization to the same allergens was rare (1%), whereas transient (only at birth, 11%) and incident (only at 12 months, 34%) sensitization was seen in substantial proportions of children. Associations of transient sensitization with maternal sensitization differed with the allergen specificities, with the strongest associations for food allergens (odds ratio OR, 10.6; 95% CI, 6.0-18.6) and the weakest associations for seasonal allergens (OR, 1.64; 95% CI, 0.94-2.86). Associations of maternal sensitization with incident sensitization were also seen. Incident sensitization was related to distinct prenatal and postnatal environmental exposures of mother and child, such as consumption of cereals for incident sensitization to seasonal allergens (OR, 0.66; 95% CI, 0.50-0.88). Conclusion IgE sensitization patterns change between birth and 12 months and are related to maternal and environmental influences.
Background It is currently discussed whether allergic sensitization may start in utero under the influence of the maternal immune system and environmental determinants. Objective To investigate the ...relationship between allergen-specific cord blood (CB) IgE levels, parental sensitization, CB cytokine production, and environmental influences. Methods As part of an ongoing multicenter birth cohort study, allergen-specific IgE antibodies against 20 common seasonal, perennial, and food allergens were measured in blood samples from 922 neonates, 922 mothers, and 835 fathers. Supernatants from stimulated CB cells were assessed for the production of IL-5, IFN-γ, IL-10, and TNF-α. Results Allergen-specific IgE antibodies were detectable in 23.9% of newborns. Contamination with maternal serum was excluded by several means of analyses, including the absence of IgA antibodies. Clear correlation between maternal and fetal IgE was found only for hen's egg, cow's milk, and soybean allergen. Fetal IgE correlated negatively with the level of IFN-γ production, but not with IL-5 and IL-10. Conclusion Allergen-specific IgE antibodies most probably of fetal origin are detectable in CB and correlate with a lowered CB IFN-γ production.
Background Microbial colonization of the airways and intestine during birth might have an effect on the risk of asthma and allergic diseases later in life. Objective We sought to evaluate the ...association between intrauterine microbial growth at the time of delivery and the development of asthma and allergic sensitization among offspring. Methods Intrauterine bacterial culture results were recorded at the time of cesarean delivery of 460 children who were born at Kuopio University Hospital during 1990–1992. When the children reached the age of 15 to 17 years, self-administered questionnaires were sent to the mothers, and 382 of the children were also examined by using skin prick tests. Results Intrauterine growth of potential pathogenic anaerobic bacteria and Streptococcus species at birth was associated with an increased risk of doctor-diagnosed asthma ever (odds ratio OR, 4.51 95% CI, 1.56–13.0; OR, 2.53 95% CI, 1.19–5.38) and doctor-diagnosed current asthma (OR, 7.34 95% CI, 2.44–22.03; OR, 3.37 95% CI, 1.46–7.76) at the age of 15 to 17 years compared with the risk seen in subjects with negative microbial cultures. These findings remained significant also after applying the Bonferroni correction. No significant association after the Bonferroni correction was detected between intrauterine microbial growth and allergic sensitization among offspring. Conclusion The results of this study indicated that specific intrauterine microbial growth at the time of birth might increase the risk of asthma among offspring through inflammatory mechanisms. These results indicate new potential targets for future studies on the effects of maternal vaginal microflora and intrauterine infection in the development of asthma among children
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