Dataset Information

Analysis of Allergen-Specific T Cell and IgE Reactivity to Different Preparations of Cow's Milk-Containing Food Extracts.

ABSTRACT: cow's milk allergy (CM) is among the most common food allergies in young children and is often outgrown by adulthood. Prior to developing a tolerance to CM, a majority of CM-allergic children may tolerate extensively-heated CM. This study aims to characterize the IgE- and T cell-reactivity to unheated CM and the progressively more heated CM-containing foods. CM-containing food extracts from muffin, baked cheese, custard and raw, pasteurized CM commercial extract were tested for skin prick test reactivity, IgE binding and T cell reactivity as assessed by IL-5 and IFNγ production. the skin prick test (SPT) reactivity was significantly decreased to muffin extract compared to raw, pasteurized CM. Both IgE- and T-cell reactivity were readily detectable against food extracts from all forms of CM. Western blot analysis of IgE reactivity revealed variability between extracts that was protein-specific. T cell-reactivity was detected against all four extracts with no significant difference in IL-5 or IFNγ production between them. our data indicate that despite reduced clinical reactivity, extracts from heated CM-containing foods retain immunogenicity when tested in vitro, particularly at the T cell level.

SUBMITTER: Chen M

PROVIDER: S-EPMC6679079 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature

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Analysis of Allergen-Specific T Cell and IgE Reactivity to Different Preparations of Cow's Milk-Containing Food Extracts.

Chen Meng M Sutherland Aaron A Birrueta Giovanni G Laubach Susan S Leonard Stephanie S Peters Bjoern B Schulten Véronique V

Cells 20190702 7

<h4>Background</h4>cow's milk allergy (CM) is among the most common food allergies in young children and is often outgrown by adulthood. Prior to developing a tolerance to CM, a majority of CM-allergic children may tolerate extensively-heated CM. This study aims to characterize the IgE- and T cell-reactivity to unheated CM and the progressively more heated CM-containing foods.<h4>Methods</h4>CM-containing food extracts from muffin, baked cheese, custard and raw, pasteurized CM commercial extract ...[more]

PMID: 31269726

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Project description:BackgroundSerum inhibition of allergen-specific IgE has been associated with competing IgG4 and non-specific polyclonal IgE. In allergen immunotherapy, beneficial responses have been associated with high IgG4/IgE ratios. Helminths potentiate antibody class switching to IgG4 and stimulate polyclonal IgE synthesis; therefore, we hypothesized a role for helminth-associated IgG4 and total IgE in protection against atopic sensitization and clinical allergy (asthma) in tropical low-income countries.MethodsAmong community residents of Ugandan rural Schistosoma mansoni (Sm)-endemic islands and a mainland urban setting with lower helminth exposure, and among urban asthmatic schoolchildren and non-asthmatic controls, we measured total, Schistosoma adult worm antigen (SWA)-specific, Schistosoma egg antigen (SEA)-specific and allergen (house dust mite [HDM] and German cockroach)-specific IgE and IgG4 by ImmunoCAP® and/or ELISA. We assessed associations between these antibody profiles and current Sm infection, the rural-urban environment, HDM and cockroach skin prick test (SPT) reactivity, and asthma.ResultsTotal IgE, total IgG4 and SWA-, SEA- and allergen-specific IgE and IgG4 levels were significantly higher in the rural, compared to the urban setting. In both community settings, both Sm infection and SPT reactivity were positively associated with allergen-specific and total IgE responses. SPT reactivity was inversely associated with Schistosoma-specific IgG4, allergen-specific IgG4/IgE ratios and total IgE/allergen-specific IgE ratios. Asthmatic schoolchildren, compared with non-asthmatic controls, had significantly higher levels of total and allergen-specific IgE, but lower ratios of allergen-specific IgG4/IgE and total IgE/allergen-specific IgE.Conclusions and clinical relevanceOur immuno-epidemiological data support the hypothesis that the IgG4-IgE balance and the total IgE-allergen-specific IgE balance are more important than absolute total, helminth- or allergen-specific antibody levels in inhibition of allergies in the tropics.

Project description:Current diagnostics for allergies, such as skin prick and radioallergosorbent tests, do not allow for inexpensive, high-throughput screening of patients. Additionally, extracts used in these methods are made from washed pollen that lacks pollen surface materials that may contain allergens.We sought to develop a high-throughput assay to rapidly measure allergen-specific IgE in sera and to explore the relative allergenicity of different pollen fractions (i.e. surface, cytoplasmic, commercial extracts). To do this, we generated a protein microarray containing surface, cytoplasmic, and commercial extracts from 22 pollen species, commercial extracts from nine non-pollen allergens, and five recombinant allergenic proteins. Pollen surface and cytoplasmic fractions were prepared by extraction into organic solvents and aqueous buffers, respectively. Arrays were incubated with <25 uL of serum from 176 individuals and bound IgE was detected by indirect immunofluorescence, providing a high-throughput measurement of IgE. We demonstrated that the allergen microarray is a reproducible method to measure allergen-specific IgE in small amounts of sera. Using this tool, we demonstrated that specific IgE clusters according to the phylogeny of the allergen source. We also showed that the pollen surface, which has been largely overlooked in the past, contained potent allergens. Although, as a class, cytoplasmic fractions obtained by our pulverization/precipitation method were comparable to commercial extracts, many individual allergens showed significant differences.These results support the hypothesis that protein microarray technology is a useful tool for both research and in the clinic. It could provide a more efficient and less painful alternative to traditionally used skin prick tests, making it economically feasible to compare allergen sensitivity of different populations, monitor individual responses over time, and facilitate genetic studies on pollen allergy.

Project description:Importance:Cow's milk formula (CMF) is used to supplement breastfeeding (BF) at birth without clear clinical evidence to support the practice. Objective:To determine whether avoiding supplementation with CMF at birth can decrease risks of sensitization to cow's milk protein and/or clinical food allergy, including cow's milk allergy (CMA), overall and in subgroups stratified by 25-hydroxyvitamin D (25[OH]D) levels. Design, Setting, and Participants:The Atopy Induced by Breastfeeding or Cow's Milk Formula (ABC) trial, a randomized, nonblinded clinical trial, began enrollment October 1, 2013, and completed follow-up May 31, 2018, at a single university hospital in Japan. Participants included 330 newborns at risk for atopy; of these, 312 were included in the analysis. Data were analyzed from September 1 through October 31, 2018. Interventions:Immediately after birth, newborns were randomized (1:1 ratio) to BF with or without amino acid-based elemental formula (EF) for at least the first 3 days of life (BF/EF group) or BF supplemented with CMF (?5 mL/d) from the first day of life to 5 months of age (BF plus CMF group). Main Outcomes and Measures:The primary outcome was sensitization to cow's milk (IgE level, ?0.35 allergen units [UA]/mL) at the infant's second birthday. Secondary outcomes were immediate and anaphylactic types of food allergy, including CMA, diagnosed by oral food challenge test or triggered by food ingestion, with food-specific IgE levels of at least 0.35 UA/mL. Subgroup analysis was prespecified by tertiles of serum 25(OH)D levels at 5 months of age. Results:Of the 312 infants included in the analysis (160 female [51.3%] and 152 male [48.7%]), 151 of 156 (96.8%) in the BF/EF and BF plus CMF groups were followed up until their second birthday. The primary outcome occurred in 24 infants (16.8%) in the BF/EF group, which was significantly fewer than the 46 infants (32.2%) in the BF plus CMF group (relative risk [RR], 0.52; 95% CI, 0.34-0.81). The middle tertile of the 25(OH)D subgroup, but not the low and high tertiles, had a significant interaction with the intervention (RR, 0.19; 95% CI, 0.07-0.50; P?=?.02). The prevalence of food allergy at the second birthday was significantly lower in the BF/EF than in the BF plus CMF groups for immediate (4 [2.6%] vs 20 [13.2%]; RR, 0.20; 95% CI, 0.07-0.57) and anaphylactic (1 [0.7%] vs 13 [8.6%]; RR, 0.08; 95% CI, 0.01-0.58) types. Conclusions and Relevance:The evidence suggests that sensitization to cow's milk and food allergy, including CMA and anaphylaxis, are primarily preventable by avoiding CMF supplementation for at least the first 3 days of life. Trial Registration:http://umin.ac.jp Identifier: UMIN000011577.

Project description:BackgroundIn our previous study about 75% of children with cow's milk allergy tolerated baked milk products, which improved their prognosis and quality of life.ObjectiveWe sought to identify biomarkers of varying degrees of clinical tolerance among a cohort of children with cow's milk allergy.MethodsOne hundred thirty-two subjects were initially classified as baked milk-reactive, baked milk-tolerant, or having "outgrown milk allergy" based on the results of oral food challenges. The baked milk-tolerant group was then divided into 3 groups based on the amount and degree of heat-denatured milk protein that they could tolerate. Serum was analyzed for allergen-specific IgE and IgG(4) levels, basophil reactivity was assessed in whole blood stimulated with serial 10-fold dilutions of milk protein, and skin prick tests (SPTs) were performed to commercial milk extract. Activated basophils were defined by using flow cytometry as CD63(bright)CD203c(+)CD123(+)HLA-DR(dim/-)CD41a(-)lineage(-). Data were analyzed by using the Jonckheere-Terpstra test.ResultsSignificant differences across the 5 clinical groups were seen for median casein- and milk-specific IgE levels, casein-specific IgG(4) levels, and casein IgE/IgG(4) ratios; milk-specific to nonspecific basophil activation ratio, median basophil reactivity, and spontaneous basophil activation (CD203c expression after stimulation with RPMI); and milk SPT wheal diameters. Casein- and milk-specific IgE level, milk-specific basophil reactivity, and milk SPT wheal diameter are all significantly greater among patients with milk allergy who react to baked milk than among those who tolerate it.ConclusionsThe majority of patients with milk allergy are able to tolerate some forms of baked milk in their diets. Different phenotypes of children with cow's milk allergy can be distinguished by casein- and milk-specific IgE levels, milk-specific basophil reactivity, and milk SPT mean wheal diameters. Spontaneous basophil activation is greater among patients with more severe clinical milk reactivity.

Dataset Information

Analysis of Allergen-Specific T Cell and IgE Reactivity to Different Preparations of Cow's Milk-Containing Food Extracts.

Publications

Analysis of Allergen-Specific T Cell and IgE Reactivity to Different Preparations of Cow's Milk-Containing Food Extracts.

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