Allergen Composition Research Articles

Total protein concentration and stability of Amb a 1 in glycerinated ragweed sublingual immunotherapy stored at room temperature and refrigerated cold temperature.

Few studies have investigated optimal storage conditions or expiration dates for sublingual immunotherapy (SLIT) formulations prepared from glycerinated allergen extracts. The objective of this study was to compare concentrations of short ragweed major allergen (Amb a 1) and total protein in SLIT formulations stored at two different temperatures. It was hypothesised that protein concentrations would show greater decline over time in a formulation stored at room temperature (RT) than in one stored under refrigeration. Two SLIT samples containing equal volumes of 20,000 PNU Amb a 1 extract were prepared and stored at refrigerated cold (CT) (2-8°C) or RT (20-24°C) for 140 days. Changes in total protein and major allergen concentration and composition were measured by Bradford assay, two-site enzyme-linked immunosorbent assay and SDS-PAGE. Presence of Amb a 1 was confirmed with Western immunoblot. Data were analysed using an analysis of covariance, with p < 0.05 considered significant. SDS-PAGE showed compositional changes in a ~26-30 kDa protein band under RT and not CT storage. The Amb a 1 concentration of the RT SLIT sample declined significantly over time, compared to that of the CT SLIT sample (F(1,8) = 47.69, p < 0.0001). There was no significant difference in total protein concentration over time between groups (F(1,8) = 1.79, p = 0.22). These results demonstrate that storage of glycerinated SLIT formulations in refrigerated CT preserved the highest concentration of the specific allergen Amb a 1, suggesting that SLIT formulations containing short ragweed should be stored under refrigeration.

Improved quality control of allergen products: Assessing the molecular allergen composition by mass spectrometry.

Natural allergen sources contain a variety of allergens, against which allergic subjects have developed individual sensitization profiles. Ideal allergen products for skin prick testing (SPT) and allergen immunotherapy (AIT) should contain the complete set of allergens of the respective allergen sources to cover all sensitization profiles. However, commercially available allergen products were shown to vary regarding their allergen composition. The qualitative allergen composition of different SPT and AIT products produced from pollen of grasses, birch, mugwort and from house dust mites was assessed by a consistent high-resolution liquid chromatography-coupled tandem mass spectrometry method (LC-MS/MS). All major, mid-tier and most minor allergens were detected in each of the investigated three batches of SPT and AIT products, demonstrating the completeness of the allergen composition and a high degree of batch-to-batch consistency. This is the first study using a single consistent high-resolution LC-MS/MS method to provide solid data on the qualitative allergen composition of SPT and AIT products manufactured from various common allergen sources. The applied method showed high reliability in qualitative batch-to-batch consistency testing and can be performed fast and with high throughput. High-resolution LC-MS/MS is applicable for process development and quality control to ensure market availability of allergen products corresponding to the composition of the respective natural allergen sources.

Spectra of sensitization to aeroallergens in patients with allergy from the upper chirchik district of the Republic of Uzbekistan

BACKGROUND: Allergic airway diseases caused by hypersensitivity to aeroallergens are the most common manifestation of atopy in children and adults. However, sensitization in the population primarily depends on the allergenic composition of the air environment. Identification of sensitization is a prerequisite for successful treatment of allergic diseases, although the structure of sensitization may have regional characteristics.&#x0D; AIM: To study the spectrum of sensitization in people with allergic diseases, namely, allergic rhinitis, bronchial asthma of varying severity, and atopic dermatitis, in the Upperchirchik district of the Tashkent region, which is characterized by a long period of flowering of weeds (wormwood, saltwort, and quinoa, from the end of August to the end of November), cereals (timothy, foxtail, rye, and bluegrass), and herbs (from the end of February to the end of July); the duration of flowering is associated with the peculiarities of climatic and geographic conditions.&#x0D; MATERIALS AND METHODS: From January to May 2022, a clinical and allergological examination was conducted on 100 patients with allergic diseases; of these, 38 were children aged 2–18 years (including 20 children with allergic rhinitis, 12 with bronchial asthma, 6 with atopic dermatitis) and 62 were adults (including 32 patients with allergic rhinitis, 13 with bronchial asthma, 17 with atopic dermatitis). To study the total IgE in the blood serum, allergen-specific IgE and standard diagnostic allergens were used for skin testing.&#x0D; RESULTS: Among all examined patients, the most frequent were intermittent and persistent forms of allergic rhinitis in 52 (52%), bronchial asthma in 25 (25%), atopic dermatitis in 23 (23%), combination of allergic rhinitis + bronchial asthma in 13 (13%), allergic rhinitis + atopic dermatitis in 12 (12%), and atopic dermatitis + bronchial asthma in 9 (9%) patients. Combined sensitization to pollen and household and food allergens was detected in 90% of the patients, monosensitization to allergens of cereal grasses (meadow Timothy and meadow bluegrass) in 6% and to allergens of weeds (wormwood and quinoa) in 4%. Sensitization to house dust (h1) was detected in 29 children and 51 adults. The frequency of sensitization to food allergens was higher in children than in adults: to cow’s milk allergens in 28.9% of children and 8.1% of adults; to egg allergens in 44.7% of children and 24.2% of adults; and to nut allergens in 38.7% of children and 34.2% of adults.&#x0D; CONCLUSION: The spectrum of sensitization to allergens in patients with allergic diseases in the Upperchirchik district of the Tashkent region is characterized by a predominance of sensitization to pollens and household allergens in children and adults, with a significant proportion of polysensitized patients in all age groups.

Food Flour Proteins with Defined Allergen Composition for Use as Reference Materials.

Food Flour Proteins with Defined Allergen Composition for Use as Reference Materials.

Aeroallergen sensitization patterns in children with allergic rhinitis from Guangzhou and Liuzhou in southern China

&lt;sec&gt;&lt;title&gt;Background&lt;/title&gt;&lt;p&gt;The sensitization patterns of allergic rhinitis (AR) to allergens exhibit global variations, influenced by diverse geographical, climatic, cultural, and genetic determinants. We aimed to contrast the allergen profiles among children belonging to distinct ethnic groups residing in two disparate provinces of China, with the objective of elucidating the impact of environmental and genetic factors on the types of allergens.&lt;/p&gt;&lt;/sec&gt;&lt;sec&gt;&lt;title&gt;Methods&lt;/title&gt;&lt;p&gt;A comparative analysis was conducted on allergen sensitizations among children with allergic rhinitis (AR) in Guangzhou and Liuzhou from 2019 to 2023. The specific IgE response to a range of inhalant allergens was evaluated utilizing the ImmunoCAP 100 system. Statistical analysis was conducted using the SPSS 20 software package. For comparisons, the Chi-square test or Fisher's exact test was employed, depending on the nature of the data and the assumptions of each test.&lt;/p&gt;&lt;/sec&gt;&lt;sec&gt;&lt;title&gt;Results&lt;/title&gt;&lt;p&gt;A total of 9684 AR children from Guangzhou and 1679 from Liuzhou were enrolled in the study. Notably, the sensitization rates toward D. &lt;italic&gt;farinae&lt;/italic&gt;, &lt;italic&gt;D. pteronyssinus&lt;/italic&gt;, cat dander, dog dander, common ragweed, and mugwort were significantly elevated in Guangzhou compared to Liuzhou. However, the sensitization rates to cockroaches exhibited no notable disparities between the two cities.&lt;/p&gt;&lt;/sec&gt;&lt;sec&gt;&lt;title&gt;Conclusions&lt;/title&gt;&lt;p&gt;The allergen composition in AR children is similar between Guangzhou and Liuzhou, with &lt;italic&gt;D. farina&lt;/italic&gt; and &lt;italic&gt;D. pteronyssinus&lt;/italic&gt; as the main allergens. However, the sensitization rates of all allergens except for cockroaches in Guangzhou are higher than those in Liuzhou. Our results suggest that the causes of allergen sensitization are complex, and genetic and environmental factors cannot be ignored.&lt;/p&gt;&lt;/sec&gt;

Novel monoclonal antibodies against house dust mite allergen Der p 21 and their application to analyze allergen extracts.

Allergen extracts and recombinant allergens are used in allergy diagnostics and immunotherapy. Since allergen extracts from different manufacturers lack proper standardization regarding their composition, monoclonal antibodies (MAbs) against specific allergen components can be used for their identification and quantification in allergen extracts. This study aimed to generate MAbs against allergen Der p 21 of Dermatophagoides pteronyssinus for the analysis of allergen extracts. Recombinant Der p 21 was expressed in E. coli and purified using affinity chromatography. MAbs against Der p 21 were generated using hybridoma technology. House dust mite (HDM) allergen extracts were analyzed using the newly developed sandwich enzyme-linked immunosorbent assay, Western blotting and microarray immunoassay. MAbs raised against recombinant Der p 21 were characterized in detail and proven to be reactive with natural Der p 21. Highly specific sandwich enzyme-linked immunosorbent assay for the quantification of Der p 21 was developed and optimized. The allergen was detected and its concentration was determined in only three of six analyzed HDM allergen extracts from different manufacturers. HDM analysis by MAb-based immunoassays shows their differences in allergen composition. The results demonstrate the importance of allergen-specific MAbs as a tool for the characterization of allergen extracts and the need for their appropriate standardization before their use for allergy diagnostics or immunotherapy.

Influence of Fermentation by Lactobacillus helveticus on the Immunoreactivity of Atlantic Cod Allergens.

Fermentation techniques may induce alterations in fish allergen immunoreactivity. In this study, the influence of fermentation with three different strains of Lactobacillus helveticus (Lh187926, Lh191404, and Lh187926) on the immunoreactivity of Atlantic cod allergens was investigated via several methods. Gradually reduced protein composition and band intensity due to the fermentation by strain Lh191404 were found in SDS-PAGE analysis, and decreased immunoreactivity of fish allergens was confirmed by Western blotting and ELISA analysis due to the fermentation of strain Lh191404. Additionally, results from nLC-MS/MS and immunoinformatics tools analysis demonstrated that the protein polypeptide and allergen composition of Atlantic cod showed evident alterations after fermentation, with the epitopes of the main fish allergens being heavily exposed and destroyed. These results indicated that the fermentation of L. helveticus Lh191404 could destroy the structure and linear epitopes of the allergens from Atlantic cod and may have considerable potential in mitigating the allergenicity of fish.

Differential patterns of fish sensitization in Asian populations: Implication for precision diagnosis

BackgroundThe current diagnostics of fish allergy lack sufficient accuracy such that more reliable tests such as component-resolved diagnosis (CRD) are urgently needed. This study aimed at identifying fish allergens of salmon and grass carp and evaluating the sensitization pattern in fish allergic subjects from two distinct populations in Asia. MethodsOne hundred and three fish allergic subjects were recruited from Hong Kong (67 subjects) and Japan (46 subjects). Western blot and mass spectrometry were used to identify allergens from salmon and grass carp. Fish allergens were purified and tested against 96 sera on ELISA to analyze patients’ sensitization pattern. The protein profiles of salmon meat prepared under different cooking methods until core temperature reached 80 °C were evaluated by SDS-PAGE and mass spectrometry. ResultsThree common allergens between salmon and grass carp, namely enolase, glycerldehyde-3-phosphate dehydrogenase (GAPDH) and parvalbumin, and two salmon-specific allergens collagen and aldolase were identified. Parvalbumin was the major allergen for both fishes showing an overall sensitization rate of 74.7%, followed by collagen (38.9%), aldolase (38.5%) and enolase (17.8%). Japanese subjects showed more diverse allergen sensitization pattern and more frequent IgE-binding to heat-labile salmon allergens. Compared with steaming and boiling, cooking by baking and frying retained more fish proteins inclusive of heat-labile allergens. ConclusionsFish allergic patients from different Asian populations show varying fish allergen sensitization profiles. The relevant extracts and components for diagnosis are population-dependent but parvalbumin and collagen are important biomarkers. Cooking methods modify allergen composition of salmon and appear to influence patients’ allergic manifestations.

Investigation of differences in allergenicity of protein from different soybean cultivars through LC/MS-MS

Soybean allergy is a health-threatening issue and identifying raw soybeans with low allergenicity is important for producing hypoallergenic soybean products. Soybean allergy is mainly triggered by soybean proteins. In this study, the protein profiles, allergen compositions, and epitopes in protein from different soybean cultivars (R1, R2 and R3) were evaluated by SDS–PAGE and LC/MS-MS, and their allergenicity was assessed by indirect ELISA and Western blot analysis using the serum IgE of patients allergic to soybeans. The lowest allergenicity was observed in R3, probably resulting from the low concentration of Gly m 4-Gly m 6. The allergenicity of soybeans is affected by multiple allergens rather than a single allergen. Venn diagram, PCA, heatmap, and peptide map analyses have shown the differences in protein and peptide profiles among soybean proteins from different soybean cultivars. Epitope analysis further demonstrated that low contents of dominant epitopes in Gly m 4 and Gly m 5 contributed to low allergenicity in R3, although R3 contained high contents of no-dominant epitopes.

Reconsider the Art of Allergen Immunotherapy

This symposium took place during the European Academy of Allergy and Clinical Immunology (EAACI) Hybrid Congress, held in Prague, Czechia, in July 2022. Stephanie Dramburg, Medical Doctor at Charité Universitätsmedizin, Berlin, Germany, explained that the traditional diagnostic work-up for allergic rhinoconjunctivitis (AR) comprises retrospective clinical history and allergen exposure assessment, extract-based diagnostics, component-resolved diagnostics (CRD), which enables markers of genuine sensitisation to be distinguished from markers of cross-reactivity, and confirmation of clinical relevance. She highlighted that molecular IgE assessment supports the diagnostic work-up and personalised risk assessment in complex cases and that confirmation of clinical relevance of IgE results is key. Furthermore, broadening of a serum IgE response is indicative of ‘molecular spreading’. Dramburg considered that digital technologies have the potential to enhance medical decisions at the point-of-care via targeted patient information, guideline- and evidence-based clinical knowledge, and prospectively collected patient- and sensor-generated data. Marek Jutel, Medical Professor at Wroclaw Medical University, Poland, and the ALL-MED Medical Research Institute, Wroclaw, Poland, described that patients with allergies show different clinical pictures due to differing sensitisation profiles assessed at the molecular level. He noted that patients with allergies react differently to different allergen doses and allergen immunotherapy (AIT) preparations, and minor/intermediate allergens are necessary, in addition to major allergens, for optimal clinical efficacy. Jutel described that allergens that are decisive for AIT efficacy are defined in grass pollen but are not yet determined for other allergen sources such as birch and house dust mite (HDM). Petra Zieglmayer, Medical Professor at Karl Landsteiner University, Krems, Austria, and Head of Vienna Challenge Chamber, Austria, discussed that patients with allergies show complex molecular sensitisation profiles and that extract preparations from different manufacturers vary in terms of allergen composition, with major and intermediate allergens not always detectable. She clarified that optimal efficacy of AIT may only be expected from preparations containing all relevant allergen components in sufficient amounts. Zieglmayer proposed that the target should be to find a match between the patient molecular sensitisation profile and the allergen preparation and that this can be achieved.

Reconsider the Art of Allergen Immunotherapy

This symposium took place during the European Academy of Allergy and Clinical Immunology (EAACI) Hybrid Congress, held in Prague, Czechia, in July 2022. Stephanie Dramburg, Medical Doctor at Charité Universitätsmedizin, Berlin, Germany, explained that the traditional diagnostic work-up for allergic rhinoconjunctivitis (AR) comprises retrospective clinical history and allergen exposure assessment, extract-based diagnostics, component-resolved diagnostics (CRD), which enables markers of genuine sensitisation to be distinguished from markers of cross-reactivity, and confirmation of clinical relevance. She highlighted that molecular IgE assessment supports the diagnostic work-up and personalised risk assessment in complex cases and that confirmation of clinical relevance of IgE results is key. Furthermore, broadening of a serum IgE response is indicative of ‘molecular spreading’. Dramburg considered that digital technologies have the potential to enhance medical decisions at the point-of-care via targeted patient information, guideline- and evidence-based clinical knowledge, and prospectively collected patient- and sensor-generated data. Marek Jutel, Medical Professor at Wroclaw Medical University, Poland, and the ALL-MED Medical Research Institute, Wroclaw, Poland, described that patients with allergies show different clinical pictures due to differing sensitisation profiles assessed at the molecular level. He noted that patients with allergies react differently to different allergen doses and allergen immunotherapy (AIT) preparations, and minor/intermediate allergens are necessary, in addition to major allergens, for optimal clinical efficacy. Jutel described that allergens that are decisive for AIT efficacy are defined in grass pollen but are not yet determined for other allergen sources such as birch and house dust mite (HDM). Petra Zieglmayer, Medical Professor at Karl Landsteiner University, Krems, Austria, and Head of Vienna Challenge Chamber, Austria, discussed that patients with allergies show complex molecular sensitisation profiles and that extract preparations from different manufacturers vary in terms of allergen composition, with major and intermediate allergens not always detectable. She clarified that optimal efficacy of AIT may only be expected from preparations containing all relevant allergen components in sufficient amounts. Zieglmayer proposed that the target should be to find a match between the patient molecular sensitisation profile and the allergen preparation and that this can be achieved.

Allergen Composition, Marketing Claims, and Affordability of Pediatric Sunscreens.

Childhood sun exposure is associated with development of future skin cancers. Sunscreens are an important tool to prevent harmful ultraviolet rays. The aims of the study are to evaluate sunscreens targeted to children and to analyze cost, marketing claims, ingredients, and allergens to help consumers select products. The top 50 pediatric sunscreens across retailers were analyzed for their cost, marketing claims, ingredients, vehicles, and containers. Ingredients were compared with the American Contact Dermatology Society 2020 Core Allergen List. The mean price was $6.20 per ounce (range, $0.25-$39.98). The mean sun protection factor was 48.5 (range, 30-100; SD, 48.5). There was a mean of 17.5 ingredients and a mean of 1.1 allergens in products. On average, products marketed as "sensitive skin" were not only significantly more expensive ($8.90 vs $3.50 per ounce, P = 0.01) but also were significantly more likely to not contain any allergens (36.0%, n = 18 vs 12%, n = 6; P = 0.05). Products with mineral-only UV blockers were significantly less likely to have any allergen when compared with products that had chemical UV blockers (5.6%, n = 1 vs 94.4%, n = 17; P = 0.02). The current market of pediatric sunscreens varies significantly in price, marketing claims, and active ingredients. Products marked as suitable for sensitive skin had significantly fewer allergens, but a majority of these products still had at least one allergen. Many sunscreens contain contact allergens, which is an important selection consideration.

Determination of Allergen Levels, Isoforms, and Their Hydroxyproline Modifications Among Peanut Genotypes by Mass Spectrometry.

The recently published reference genome of peanuts enables a detailed molecular description of the allergenic proteins of the seed. We used LC-MS/MS to investigate peanuts of different genotypes to assess variability and to better describe naturally occurring allergens and isoforms. Using relative quantification by mass spectrometry, minor variation of some allergenic proteins was observed, but total levels of Ara h 1, 2, 3, and 6 were relatively consistent among 20 genotypes. Previously published RP-HPLC methodology was used for comparison. The abundance of three Ara h 3 isoforms were variable among the genotypes and contributed to a large proportion of total Ara h 3 where present. Previously unpublished hydroxyproline sites were identified in Ara h 1 and 3. Hydroxylation did not vary significantly where sites were present. Peanut allergen composition was largely stable, with only some isoforms displaying differences between genotypes. The resulting differences in allergenicity are of unknown clinical significance but are likely to be minor. The data presented herein allow for the design of targeted MS methodology to allow the quantitation and therefore control of peanut allergens of clinical relevance and observed variability.

Allergens and marketing claims of the most popular baby moisturizers: A product analysis

To the Editor: Pediatric allergic contact dermatitis in the United States has an estimated prevalence of 16.5% in the general pediatric population, with an increased prevalence in pediatric patients with atopic dermatitis.1,2 Moisturizers are the foundation of skin care, especially in infants with immature skin barriers and increased risk of atopic dermatitis and allergic contact dermatitis; however, the contact allergens present in these products are unknown. Therefore, we aimed to investigate the allergen composition and marketing claims of the most-reviewed moisturizers targeted at babies.

Dipeptidyl peptidase IV of the Vespa velutina nigrithorax venom is recognized as a relevant allergen

BackgroundVespa velutina nigrithorax (VVN), typically known as the Asian yellow-legged wasp, has been one of the most significant invasive species in western Europe since 2010. Currently, VVN has become the most prevalent cause of Hymenoptera anaphylaxis in the north and northwestern Spain. For this reason, it is crucial to diagnose anaphylaxis cases in the acute moment for carrying out the best available treatment as soon as possible. ObjectiveTo achieve a complete understanding of the venom allergen composition that will help to develop efficient diagnostics and immunotherapy treatments on the basis of this venom. MethodsIn this study, autochthonous VVN venom was obtained and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, isoelectric focusing, followed by a mass spectrometry analysis. In addition, the allergenic sensitization profile of patients diagnosed with allergy to VVN in the Allergology Service of Navarra University Hospital between the years 2017 and 2020 was studied by immunoblotting and specific IgE (ImmunoCAP, Thermo Fisher Scientific, Uppsala, Sweden). ResultsTwo new allergens (dipeptidyl peptidase IV and serin protease) were identified in the autochthonous VVN venom, and their identity was confirmed by liquid chromatography–mass spectrometry analysis. The study by ImmunoCAP using sera from 12 patients who had a systemic reaction after a VVN sting revealed groups 5 and 1 as predominant allergens (92% and 34%, respectively). Furthermore, the immunoblotting assay recognized dipeptidyl peptidase IV (50%) in the sera of these patients. ConclusionSerine protease and the dipeptidyl peptidase IV are components of the VVN venom, and the latter is an allergen recognized in the studied population.

Major Peanut Allergens Ara h 1, Ara h 2 and Ara h 8 Are Degraded and Fragmented Following High-Pressure and Temperature Autoclaving

Peanut allergy is a growing global health concern and is the leading cause of fatal anaphylaxis. The effects of various thermal processing methods on peanut allergenicity have been evaluated in recent decades. However, the specific allergen composition and structure under each condition has yet to be confirmed.

Doses of Specific Allergens in Early Introduction Foods for Prevention of Food Allergy

Consumption of common allergenic foods, such as peanut, in early life can reduce the risk of food allergy among high-risk children and is recommended in revised clinical guidelines. Commercial early allergen introduction foods (EIF) containing single or multiple allergenic foods for feeding infants are promoted to consumers and health care providers as aids to prevent food allergy. To determine the concentration and doses of major food allergens in EIF. Extracts from 32 EIF and 4 control foods were analyzed for 17 allergens: Ara h 1, Ara h 3, Ara h 6, Bos d 5, Bos d 11, Gal d 1, Gal d 2, Ana o 3, Cor a 9, Jug r 1, Gly m 5, Ses i 1, Api g 1, Sin a 1, Cyp c 1, shrimp tropomyosin, and Tri a 19 using a validated fluorescent multiplex array. Ara h 2 was measured by enzyme-linked immunosorbent assay. The EIF comprised 1-8 samples of 32 foods (n= 86). Combined peanut allergen levels of up to 26,000 μg/g were measured in peanut puffs (doses of 65-182 mg per 7 g serving). Peanut allergens were not detected in mixed food blend puffs. Major allergen levels of >10,000 μg/g were found in several milk, egg, and peanut powders, or combinations thereof, with cumulative allergen doses of 159-2946 mg in the EIF. Mixed food blend powders, puffs crackers, and fruit sauces contained much lower allergen levels, often <10 μg/g, and some had undetectable allergens. The allergen concentration in these EIF varied over a >3 log range and provided lower cumulative doses of allergen. Significant variability in allergen composition, concentration, and dose per serving were observed in EIF containing the same foods. The doses of allergens consumed by potentially at-risk infants in early life were EIF dependent. Guidelines should be established to enable consumers and health care providers to make informed decisions about EIF and to improve the formulation and standardization of EIF for prevention of food allergy.

Identification and Purification of Novel Low-Molecular-Weight Lupine Allergens as Components for Personalized Diagnostics.

Lupine flour is a valuable food due to its favorable nutritional properties. In spite of its allergenic potential, its use is increasing. Three lupine species, Lupinus angustifolius, L. luteus, and L. albus are relevant for human nutrition. The aim of this study is to clarify whether the species differ with regard to their allergen composition and whether anaphylaxis marker allergens could be identified in lupine. Patients with the following characteristics were included: lupine allergy, suspected lupine allergy, lupine sensitization only, and peanut allergy. Lupine sensitization was detected via CAP-FEIA (ImmunoCAP) and skin prick test. Protein, DNA and expressed sequence tag (EST) databases were queried for lupine proteins homologous to already known legume allergens. Different extraction methods applied on seeds from all species were examined by SDS-PAGE and screened by immunoblotting for IgE-binding proteins. The extracts underwent different and successive chromatography methods. Low-molecular-weight components were purified and investigated for IgE-reactivity. Proteomics revealed a molecular diversity of the three species, which was confirmed when investigated for IgE-reactivity. Three new allergens, L. albus profilin, L. angustifolius and L. luteus lipid transfer protein (LTP), were identified. LTP as a potential marker allergen for severity is a valuable additional candidate for molecular allergy diagnostic tests.

Identification of the amino-terminal fragment of Ara h 1 as a major target of the IgE-binding activity in the basic peanut protein fraction.

Small, basic peanut proteins are often poorly extracted in pH-neutral buffers that are optimal for the extraction of peanut storage proteins such as Ara h 1. As a result, such proteins are easily missed as potential allergens. To analyse the allergenic composition of the basic peanut protein (BPP) fraction. A peanut extract prepared at pH 4 was fractionated by physicochemical procedures. Chemical analysis was performed by SDS-PAGE and mass spectrometry. Because immunoblotting was found to be inefficient for most of these small basic proteins, IgE-binding activity was measured by coupling the fractions to CNBr-activated Sepharose, followed by incubation with sera from 55 Dutch peanut-allergic children and 125 I-labelled anti-IgE. Most IgE reactivity of the BPP fraction was due to the 5-7kDa amino-terminal fragment of Ara h 1. This finding was confirmed by the use of the fragment in recombinant form, to which 25/55 of the sera was IgE-positive. The amino-terminal fragment of Ara h 1, a member of a family of small anti-microbial proteins, is an allergen independent of the carboxy-terminal fragment of Ara h 1.

Year-to-year variation of the elemental and allergenic contents of Ailanthus altissima pollen grains: an allergomic study.

The Ailanthus altissima pollen (AAP) has been reported as an emerging aeroallergen worldwide. This paper aims at examining the allergen pattern and the elemental composition of A. altissima pollen collected during two consecutive seasons (2014 and 2015). A gel-based allergomic study and SEM coupled to energy-dispersive X-ray (EDX) analysis have been carried out in order to evaluate the allergenic and elemental composition of AAP in two consecutive years. The IgE reactive patterns of 2014 and 2015 AAP PBS extracts were compared using the serum of a 31-year-old woman suffering from severe pollinosis symptoms to AAP. The EDX analysis revealed an important year-to-year variation in the ratios of some polluting elements such as nickel, sulfur, aluminum, lead, and copper. Gel alignments and comparative immunoproteomic analyses showed differential protein expression and IgE reactive patterns between AAPs collected in 2014 and 2015 pollinating seasons. From 20 distinct IgE-reactive spots detected in AAP extracts, 13 proteins showed higher expression in 2014 sample, while 7 allergen candidates exhibited an increased expression in AAP collected in 2015. Matrix-assisted laser desorption ionization-MS/MS analyses led to the identification of 13 IgE-binding proteins with confidence, all belonging to well-known allergenic protein families, i.e., enolase, calreticulin, and pectate lyase. Overall, the 2014 AAP showed higher concentrations of urban polluting elements as well as an increased expression of allergenic pectate lyase isoforms of about 52kDa. This study demonstrates that the implementation of allergomic tools for the safety assessment of newly introduced and invasive plant species would help to the comprehensive monitoring of proteomic and transcriptomic alterations involving environmental allergens.