59 research outputs found

    Ara h 6 Complements Ara h 2 as an Important Marker for IgE Reactivity to Peanut

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    The similarities of two major peanut allergens, Ara h 2 and Ara h 6, in molecular size, amino acid sequence, and structure have made it difficult to obtain natural Ara h 6 free of Ara h 2. The objectives of this study were to purify natural Ara h 6 that is essentially free of Ara h 2 and to compare its IgE reactivity and potency in histamine release assays to Ara h 2. SDS-PAGE of the highly purified allergen (\u3c0.01% Ara h 2) revealed a single 14.5kD band and the identity of Ara h 6 was confirmed by LC-MS/MS. Ara h 6 showed a higher seroprevalence in chimeric-IgE ELISA (n=54), but a weaker biological activity in basophil histamine release assays than Ara h 2. Purified Ara h 6 will be useful for diagnostic IgE antibody assays, as well as molecular and cellular studies to investigate the immunological mechanisms of peanut allergy

    Ara h 6 Complements Ara h 2 as an Important Marker for IgE Reactivity to Peanut

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    The similarities of two major peanut allergens, Ara h 2 and Ara h 6, in molecular size, amino acid sequence, and structure have made it difficult to obtain natural Ara h 6 free of Ara h 2. The objectives of this study were to purify natural Ara h 6 that is essentially free of Ara h 2 and to compare its IgE reactivity and potency in histamine release assays to Ara h 2. SDS-PAGE of the highly purified allergen (\u3c0.01% Ara h 2) revealed a single 14.5kD band and the identity of Ara h 6 was confirmed by LC-MS/MS. Ara h 6 showed a higher seroprevalence in chimeric-IgE ELISA (n=54), but a weaker biological activity in basophil histamine release assays than Ara h 2. Purified Ara h 6 will be useful for diagnostic IgE antibody assays, as well as molecular and cellular studies to investigate the immunological mechanisms of peanut allergy

    Selection of Pru p 3 hypoallergenic peach and nectarine varieties

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    To the Editor, Peach is an important fruit consumed worldwide. However, it is also one of the most frequently reported allergenic fruits.1 Component diagnosis of peach allergy indicates Pru p 1, Pru p 2, Pru p 3, Pru p 4, Pru p 7, and Pru p 9 are involved.2, 3 Pru p 3 is the dominant allergen responsible for severe allergic reaction,4 and it is considered to be the primary sensitizer to other LTPs in Mediterranean and Central Europe.5 The levels of Pru p 3 differ between varieties.6 To date, measurement of Pru p 3 in a limited number of peach and nectarines from Spain, United States, and Italy has been reported.7 Significant variation of allergen concentration in processed foods containing peach has also been observed.8 The content of Pru p 3 of peach/nectarine determines the potential risk for peach allergic patients. China is the origin of peach with representative genetic diversity to be explored for hypoallergenic varieties.9 A core collection of 103 varieties cultivated in Jiaxing, Zhejiang Province were selected to represent this diversity, including 23 nectarines and 80 peach varieties (with fruit hair, round or flat, 77 cultivated, three wild) (Table S1). The soluble solid content (SSC), ripening date, and peach aroma intensity were recorded. Specific methods are detailed in the Supporting Information. Pru p 3 was quantified by ELISA based on our previous research.6info:eu-repo/semantics/publishedVersio

    Joint assessment of white matter integrity, cortical and subcortical atrophy to distinguish AD from behavioral variant FTD: A two-center study

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    We investigated the ability of cortical and subcortical gray matter (GM) atrophy in combination with white matter (WM) integrity to distinguish behavioral variant frontotemporal dementia (bvFTD) from Alzheimer's disease (AD) and from controls using voxel-based morphometry, subcortical structure segmentation, and tract-based spatial statistics. To determine which combination of MR markers differentiated the three groups with the highest accuracy, we conducted discriminant function analyses. Adjusted for age, sex and center, both types of dementia had more GM atrophy, lower fractional anisotropy (FA) and higher mean (MD), axial (L1) and radial diffusivity (L23) values than controls. BvFTD patients had more GM atrophy in orbitofrontal and inferior frontal areas than AD patients. In addition, caudate nucleus and nucleus accumbens were smaller in bvFTD than in AD. FA values were lower; MD, L1 and L23 values were higher, especially in frontal areas of the brain for bvFTD compared to AD patients. The combination of cortical GM, hippocampal volume and WM integrity measurements, classified 97-100% of controls, 81-100% of AD and 67-75% of bvFTD patients correctly. Our results suggest that WM integrity measures add complementary information to measures of GM atrophy, thereby improving the classification between AD and bvFTD

    Cross-reactive carbohydrate determinant-specific IgE obscures true atopy and exhibits ⍺-1,3-fucose epitope-specific inverse associations with asthma.

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    BACKGROUND: In high-income, temperate countries, IgE to allergen extracts is a risk factor for, and mediator of, allergy-related diseases (ARDs). In the tropics, positive IgE tests are also prevalent, but rarely associated with ARD. Instead, IgE responses to ubiquitous cross-reactive carbohydrate determinants (CCDs) on plant, insect and parasite glycoproteins, rather than to established major allergens, are dominant. Because anti-CCD IgE has limited clinical relevance, it may impact ARD phenotyping and assessment of contribution of atopy to ARD. METHODS: Using an allergen extract-based test, a glycan and an allergen (glyco)protein microarray, we mapped IgE fine specificity among Ugandan rural Schistosoma mansoni (Sm)-endemic communities, proximate urban communities, and importantly in asthmatic and nonasthmatic schoolchildren. RESULTS: Overall, IgE sensitization to extracts was highly prevalent (43%-73%) but allergen arrays indicated that this was not attributable to established major allergenic components of the extracts (0%-36%); instead, over 40% of all participants recognized CCD-bearing components. Using glycan arrays, we dissected IgE responses to specific glycan moieties and found that reactivity to classical CCD epitopes (core β-1,2-xylose, α-1,3-fucose) was positively associated with sensitization to extracts, rural environment and Sm infection, but not with skin reactivity to extracts or sensitization to their major allergenic components. Interestingly, we discovered that reactivity to only a subset of core α-1,3-fucose-carrying N-glycans was inversely associated with asthma. CONCLUSIONS: CCD reactivity is not just an epiphenomenon of parasite exposure hampering specificity of allergy diagnostics; mechanistic studies should investigate whether specific CCD moieties identified here are implicated in the protective effect of certain environmental exposures against asthma

    Do helminth infections underpin urban-rural differences in risk factors for allergy-related outcomes?

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    BACKGROUND: It is proposed that helminth exposure protects against allergy-related disease, by mechanisms that include disconnecting risk factors (such as atopy) from effector responses. OBJECTIVE: We aimed to assess how helminth exposure influences rural-urban differences in risk factors for allergy-related outcomes in tropical low- and middle-income countries. METHODS: In cross-sectional surveys in Ugandan rural Schistosoma mansoni (Sm)-endemic islands, and in nearby mainland urban communities with lower helminth exposure, we assessed risk factors for atopy (allergen-specific skin prick test [SPT] reactivity and IgE [asIgE] sensitization) and clinical allergy-related outcomes (wheeze, urticaria, rhinitis and visible flexural dermatitis), and effect modification by Sm exposure. RESULTS: Dermatitis and SPT reactivity were more prevalent among urban participants, urticaria and asIgE sensitization among rural participants. Pairwise associations between clinical outcomes, and between atopy and clinical outcomes, were stronger in the urban survey. In the rural survey, SPT positivity was inversely associated with bathing in lakewater, Schistosoma-specific IgG4 and Sm infection. In the urban survey, SPT positivity was positively associated with age, non-Ugandan maternal tribe, being born in a city/town, BCG scar and light Sm infection. Setting (rural vs urban) was an effect modifier for risk factors including Sm- and Schistosoma-specific IgG4. In both surveys, the dominant risk factors for asIgE sensitization were Schistosoma-specific antibody levels and helminth infections. Handwashing and recent malaria treatment reduced odds of asIgE sensitization among rural but not urban participants. Risk factors for clinical outcomes also differed by setting. Despite suggestive trends, we did not find sufficient evidence to conclude that helminth (Sm) exposure explained rural-urban differences in risk factors. CONCLUSIONS AND CLINICAL RELEVANCE: Risk factors for allergy-related outcomes differ between rural and urban communities in Uganda but helminth exposure is unlikely to be the sole mechanism of the observed effect modification between the two settings. Other environmental exposures may contribute significantly

    Efficacy of the Enquiring About Tolerance (EAT) study among infants at high risk of developing food allergy.

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    BACKGROUND: The Enquiring About Tolerance (EAT) study was a randomized trial of the early introduction of allergenic solids into the infant diet from 3 months of age. The intervention effect did not reach statistical significance in the intention-to-treat analysis of the primary outcome. OBJECTIVE: We sought to determine whether infants at high risk of developing a food allergy benefited from early introduction. METHODS: A secondary intention-to-treat analysis was performed of 3 groups: nonwhite infants; infants with visible eczema at enrollment, with severity determined by SCORAD; and infants with enrollment food sensitization (specific IgE ≥0.1 kU/L). RESULTS: Among infants with sensitization to 1 or more foods at enrollment (≥0.1 kU/L), early introduction group (EIG) infants developed significantly less food allergy to 1 or more foods than standard introduction group (SIG) infants (SIG, 34.2%; EIG, 19.2%; P = .03), and among infants with sensitization to egg at enrollment, EIG infants developed less egg allergy (SIG, 48.6%; EIG, 20.0%; P = .01). Similarly, among infants with moderate SCORAD (15-<40) at enrollment, EIG infants developed significantly less food allergy to 1 or more foods (SIG, 46.7%; EIG, 22.6%; P = .048) and less egg allergy (SIG, 43.3%; EIG, 16.1%; P = .02). CONCLUSION: Early introduction was effective in preventing the development of food allergy in specific groups of infants at high risk of developing food allergy: those sensitized to egg or to any food at enrollment and those with eczema of increasing severity at enrollment. This efficacy occurred despite low adherence to the early introduction regimen. This has significant implications for the new national infant feeding recommendations that are emerging around the world

    The development of TH2 responses from infancy to 4 years of age and atopic sensitization in areas endemic for helminth infections

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    BACKGROUND: Helminth infections and allergies are associated with TH(2) responses. Whereas the development of TH(2) responses and allergic disorders in pediatric populations has been examined in affluent countries, no or little data exist from low income regions of the world. The aim of this study is to examine factors influencing the development of TH(2) responses of children born in areas endemic for helminth infections and to relate these factors to atopic sensitization at 4 years of age. METHODS: Data were collected from pregnant mothers on helminth infections, education and socioeconomic status (SES). Total IgE, IL-5 in response to mitogen, and helminth antigens were measured in children at 2, 5, 12, 24 and 48 months of age. Skin prick testing (SPT) and allergen-specific IgE were determined at 4 years of age. RESULTS: Strong TH(2) responses were seen at 5 months of age and increased with time. Although maternal filarial infection was associated with helminth-antigen specific TH(2) responses, it was low maternal education or SES but not helminth infection, which was associated with the development of high total IgE and PHA-induced IL-5. At 4 years of age when allergen reactivity was assessed by SPT, the high general TH(2) responses did not translate into higher prevalence of SPT. The risk factor for SPT reactivity was low maternal education which decreased the risk of SPT positivity to allergens (adjusted OR, 0.32; 95% CI, 0.12 – 0.87) independently of maternal filarial infection which tended to reduce the child’s risk for being SPT positive (adjusted OR, 0.35; 95% CI, 0.07 – 1.70). CONCLUSIONS: In areas endemic for helminths, potent TH(2) responses were seen early in life, but did not translate into a higher SPT reactivity to allergens. Therefore, in many parts of the world TH(2) responses in general and IgE in particular cannot be used for diagnosis of allergic diseases

    Artemisia pollen allergy in China : Component-resolved diagnosis reveals allergic asthma patients have significant multiple allergen sensitization

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    Background: Artemisia pollen allergy is a major cause of asthma in Northern China. Possible associations between IgE responses to Artemisia allergen components and clinical phenotypes have not yet been evaluated. This study was to establish sensitization patterns of four Artemisia allergens and possible associations with demographic characteristics and clinical phenotypes in three areas of China. Methods: Two hundred and forty patients allergic to Artemisia pollen were examined, 178 from Shanxi and 30 from Shandong Provinces in Northern China, and 32 from Yunnan Province in Southwestern China. Allergic asthma, rhinitis, conjunctivitis, and eczema symptoms were diagnosed. All patients sera were tested by ImmunoCAP with mugwort pollen extract and the natural components nArt v 1, nArt ar 2, nArt v 3, and nArt an 7. Results: The frequency of sensitization and the IgE levels of the four components in Artemisia allergic patients from Southwestern China were significantly lower than in those from the North. Art v 1 and Art an 7 were the most frequently recognized allergens (84% and 87%, respectively), followed by Art v 3 (66%) and Art ar 2 (48%). Patients from Northern China were more likely to have allergic asthma (50%) than patients from Southwestern China (3%), and being sensitized to more than two allergens increased the risk of allergic asthma, in which cosensitization to three major allergens Art v 1, Art v 3, and Art an 7 is prominent. Conclusions: Componentresolved diagnosis of Chinese Artemisia pollenallergic patients helps assess the potential risk of mugwortassociated allergic asthma.(VLID)329956

    Development of a hypoallergenic recombinant parvalbumin for first-in-man subcutaneous immunotherapy of fish allergy.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.The FAST (food allergy-specific immunotherapy) project aims at developing safe and effective subcutaneous immunotherapy for fish allergy, using recombinant hypoallergenic carp parvalbumin, Cyp c 1.Preclinical characterization and good manufacturing practice (GMP) production of mutant Cyp (mCyp) c 1.Escherichia coli-produced mCyp c 1 was purified using standard chromatographic techniques. Physicochemical properties were investigated by gel electrophoresis, size exclusion chromatography, circular dichroism spectroscopy, reverse-phase high-performance liquid chromatography and mass spectrometry. Allergenicity was assessed by ImmunoCAP inhibition and basophil histamine release assay, immunogenicity by immunization of laboratory animals and stimulation of patients' peripheral blood mononuclear cells (PBMCs). Reference molecules were purified wild-type Cyp c 1 (natural and/or recombinant). GMP-compliant alum-adsorbed mCyp c 1 was tested for acute toxicity in mice and rabbits and for repeated-dose toxicity in mice. Accelerated and real-time protocols were used to evaluate stability of mCyp c 1 as drug substance and drug product.Purified mCyp c 1 behaves as a folded and stable molecule. Using sera of 26 double-blind placebo-controlled food-challenge-proven fish-allergic patients, reduction in allergenic activity ranged from 10- to 5,000-fold (1,000-fold on average), but with retained immunogenicity (immunization in mice/rabbits) and potency to stimulate human PBMCs. Toxicity studies revealed no toxic effects and real-time stability studies on the Al(OH)3-adsorbed drug product demonstrated at least 20 months of stability.The GMP drug product developed for treatment of fish allergy has the characteristics targeted for in FAST: i.e. hypoallergenicity with retained immunogenicity. These results have warranted first-in-man immunotherapy studies to evaluate the safety of this innovative vaccine.info:eu-repo/grantAgreement/EC/FP7/20187
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