Bet V1 Research Articles

Comprehensive analysis of secondary metabolite biosynthetic gene clusters in Helianthus annuus L.: A bioinformatics approach

Plant secondary metabolite gene clusters are regions within the plant genome that encode enzymes and proteins involved in the biosynthesis of secondary metabolites. Helianthus annuus L. is a significant oilseed plant with economic importance. This study aims to comprehensively identify secondary metabolite biosynthetic gene clusters within H. annuus using bioinformatics tools, shedding light on the functions of the enzymes involved. In this study, the plantiSMASH software was utilized to predict secondary metabolite biosynthetic gene clusters in H. annuus. The results from plantiSMASH were analyzed to identify the biosynthetic gene clusters for secondary metabolites on each chromosome. The biological and molecular functions of the enzymes within these clusters were predicted using data from the relevant articles. According to the obtained data, H. annuus lacks a biosynthetic gene cluster on chromosomes four, seven, and fifteen. The identified gene clusters in this plant are polyketide, saccharide, saccharide-terpene, alkaloid, putative, and terpene. The enzyme categories found in secondary metabolite biosynthetic gene clusters include Methyltransferase, Ketosynthase, Glycosyltransferase, BAHD acyltransferase, Dioxygenase, CoA-ligase, Epimerase, PRISE enzymes, Prenyltransferase, Oxidoreductase, Aminotransferase, Copper amine oxidase, Cytochrome P450, Terpene synthase, and Pictet-Spengler enzyme (Bet v1). This comprehensive analysis provides a foundation for further investigations into the biosynthesis of secondary metabolites in H. annuus, offering valuable insights for researchers exploring the medicinal and pharmaceutical potential of this plant species.

Allergy mapping in children with allergic rhinitis in different subjects of the Russian Federation

Given the climatic and geographical location and differences in the change of seasons in the Russian Federation, there is a marked heterogeneity in the representation of respiratory allergens. Obviously, in the case of double or triple sensitization, the diagnosis of its true picture is a difficult task. In such cases, allergy-component analysis is an extremely necessary stage of allergological examination. Purpose of the study: to assess the sensitization spectrum of AR patients in the age group from 3 to 17 years inclusive, living in different regions of the Russian Federation. Comparative analysis of differences in the sensitization spectrum of AR patients in the Republic of Ingushetia in different age groups. The study involved 47 patients, 36 of them were children under 18 years of age: Moscow n = 9 (Central Federal District), Samara n = 8 (Volga Federal District), Magas n = 19 (North Caucasus Federal District, Republic of Ingushetia). Also, 11 patients aged 18 years and older from Magas city took part in the study. The results obtained by ImmunoCAP ISAC and ALEX2 immune solid-phase allergy test were analyzed. The numerical values of the main respiratory allergens were evaluated, in patients with clinical signs of AR in the period from 01.01.2023 to 27.01.2024. The diagnosis of AR was made according to generally accepted criteria for diagnosis. The main causative factor of AR formation is the major allergen of birch pollen (Bet v1). However, for the Central Federal District, heterogeneity of representation in the group of buciferous trees was noted, which should be taken into account when planning allergen-specific immunotherapy. The spectrum of sensitization of children with AR in the North Caucasian Federal District (Magas) differs significantly from the Central and Volga Federal Districts, where the main major allergen of Amb a 1 ragweed pollen forms the etiological basis of AR formation. When comparing patients with AR of different age groups from Magas city, no differences in the sensitization spectrum were found. The results indicate a high degree of importance of allergy-component diagnostics to improve the effectiveness of allergen-specific immunotherapy.

Mapping of IgE cross-reactivity of Gly m 4, Gly m 5 and Gly m 6 soybean allergens in patients with atopic diseases

Currently, a significant portion of the food consists of multiple different ingredients. Soybean proteins have been widely used for production of these combined foodstuffs. Meanwhile, soy proteins may contain a wide range of allergens, and even, if present in small amounts, they can cause severe allergic reactions due to cross-reactivity. The aims of our study were to evaluate the prevalence of sensitization to soybean allergen components Gly m 4, Gly m 5 and Gly m 6, and to map their IgE cross-reactivity with homologous proteins of Bet v1-like proteins and cupin proteins in patients with atopic disorders. We have studied IgE’s to 112 allergenic components of plant and animal origin in blood sera from 54 patients with history of allergy, using the ImmunoCap ISAC method. The results were analyzed by means of MS Excel program using parametric statistical criteria. Results: In patients with atopic diseases, we have detected serum IgE to the rGly m 4 allergic component (5 patients out of 29; 17.24%). Frequency of sIgE detection to rGly m 5 (3 patients of 29; 10.24%) and rGly m 6 (1 patient of 29; 3.44%) was less pronounced. Cross-reactive sIgE was detected only to allergens of the Bet v1 superfamily. The strongest relationship was found between sIgE level to rGly m 4 and rBet v1 (R = 0.68; p = 0.001). Another IgE cross-reaction was found between soybean rGly m 4 and alder pollen rAln g1 (R = 0.681; p = 0.000). IgE antibodies to rGly m 4 may also cross-react with kiwi rAct d8 (R = 0.59; p = 0.001). We have also found a weak correlation between sIgE to soybean rGly m 4 and two hazelnut rCor a1 isoforms: rCor a 1.01 (R = 0.42; p = 0.023), and rCor a 1.04 (R = 0.39; p = 0.036). The IgE cross-reactivity profile of the soy allergens revealed in this study is important for improvement of testing strategy for the presence of causally significant allergens. This finding will help to avoid the development of hidden cross-reactions that trigger both oral and respiratory allergic processes in subjects with allergic pathology. Moreover, this will enable administration of optimal diets and develop technologies for development of hypoallergenic food products.

Co-sensitizations to Gibberellin Regulated Proteins (GRPs) in Italy: results of a polycentric study.

Background. Gibberellin Regulated Proteins (GRPs) are small glycoproteins that induce allergy to various types of fruit. This study aimed to evaluate co-sensitization to cypress pollen and other molecules responsible for fruit allergy, such as nsLTP (Pru p 3), PR-10 (Bet v1), and Profilin (Bet v2). Methods. Sixty subjects sensitized to peach GRP (Pru p 7) were consecutively recruited from four Italian centers: 28 males and 32 females (mean age 37.9 years; range 11-79). Specific IgE for Pru p 7, Pru p 3, Bet v 1, Bet v 2, cypress pollen extract (Cup s), and Cup a 1 were determined in all subjects. Results. Sensitization rates to Cup s, Cup a 1, Pru p 3, Bet v 1, and Bet v 2 in the entire studied population were 90.0%, 83.3%, 45.8%, 40.0%, and 30.0%, respectively. In subjects residing in Northern Italy, the respective sensitization rates were 96.4%, 80.0%, 50.0%, 73.3%, and 40.0%, while in those residing in Southern Italy, they were 83.3%, 86.7%, 40.0%, 6.7%, and 20.0%. The only significant difference was observed for PR-10 (p less than 0.0001) Co-sensitization to PR-10 was found to be associated with a reduced risk of anaphylaxis (OR: 0.125). Allergic reactions were most commonly triggered by peach (26/40), followed by orange (12/40), with other foods being less frequently implicated. Conclusions. This study confirms a high association between sensitization to Pru p 7 and cypress pollen and highlights a high percentage of co-sensitization to nsLTP, PR-10, and profilin. PR-10 emerged as a protective factor against anaphylaxis.

PREVALENCE OF SENSITIZATION TO AIRBORNE ALLERGENS IN PATIENTS WITH ALLERGIC RHINITIS AND ASTHMA IN UKRAINE

Background. The distribution of sensitization among children and adolescence with allergic rhinitis (AR) and asthma and their impact on various allergic symptoms have been analyzed.
 Aim: investigate the distribution of sensitization among children with AR and asthma of the Ukrainian population.
 Material and methods. The study involved 280 children with AR and asthma aged 2–18 years. They were tested for sIgE on the most common allergens among Ukrainians - Dermatophagoides pteronyssinus, Dermatophagoides farinae, dog, cat, cockroach, birch (t03, Bet v1, Bet v2, Bet v4), plane tree, timothy (g06, Phl p1, Phl , Phl p6, Phl p7, Phl p12), ragweed, mugwort and Alternaria. Measurements of sIgE were performed by Western blotting according to the manufacturer's protocol (Simesta-Medivis, Ukraine-Germany).
 Results. Among the sensitized subjects, 165 were sensitive to pollen allergens, sIgE was positive to birch in 64 subjects (22.5%), to mugwort ‒ 65 subjects (25.4%), ragweed ‒ 110 subjects (42.5%), timothy ‒ 69 subjects (24.6%), plane tree ‒ 12 subjects (5%). Positive sIgE to feline allergen was found in 114 (43.3%), dogs ‒ 77 (32.1%), Dermatophagoides pteronyssinus ‒ 66 (24.6%), Dermatophagoides farinae ‒ 32 (12%), Alternaria ‒ 38 (15 %), cockroaches ‒ 25 (10%).
 Conclusions. Sensitization to airborne allergens is significantly associated with asthma and AR. The most important inhalant allergens consist of pollens (trees, grasses, and weeds), house dust mites, molds and animal dander. Among sensitive subjects to pollen allergens, allergy to ragweed was most spread.

Allergy screening with extract-based skin prick tests demonstrates higher sensitivity over in vitro molecular allergy testing.

As extract-based skin testing as well as in vitro tests for major allergens have their own advantages, both procedures are usually performed in routine settings. In times of shortages in medical staff and supplies, we asked ourselves, how many patients would be underdiagnosed, if only one test could be used. In a retrospective analysis, we investigated a cohort of 2646 patients seen by a single physician in a large Austrian outpatient allergy clinic in 2018. Only patients with an allergen source-specific history and pairs of extract-based skinprick (SPT) and in vitro molecular allergy tests to major allergens were included. For all tested allergen sources, sensitivity was higher for SPT than for sIgE-based molecular allergy testing. Concerning 1006 birch pollen-allergic patients, 791 (78.6%) had positive results with both tests, while 153 (15.2%) only with the SPT and 62 (6.2%) only with the sIgE to Bet v1. The other allergen sources showed similar results: For house dust mite 816/1120 (72.9%), grass pollen 1077/1416 (76.1%) and cat 433/622 (69.6%) remained test-positive with both procedures, whereas in 276 (24.6%), 224 (15.8%) and 173 (27.8%) times only the SPT and 28 (2.5%), 115 (8.1%) and 16 (2.6%) times only the sIgE to Der p1/2/23, Phl p1/5 and Fel d1 showed a positive result. Each comparison was statistically significant (each p<0.0001, Chi-squared test). Screening for allergy with major molecular allergens has lower sensitivity when compared with extract-based skin tests. A combination of both is required for an optimal sensitivity.

Air pollution in the places of Betula pendula growth and development changes the physicochemical properties and the main allergen content of its pollen.

Pollen allergy becomes an increasing problem for humans, especially in the regions, where the air pollution level increases due to the traffic and urbanization. These factors may also affect the physiological activity of plants, causing changes in pollen allergenicity. The aim of the study was to estimate the influence of air pollutants on the chemical composition of birch pollen and the secondary structures of the Bet v1 protein. The research was conducted in seven locations in Malopolska region, South of Poland of a different pollution level. We have found slight fluctuations in the values of parameters describing the photosynthetic light reactions, similar spectra of leaf reflectance and the negligible differences in the discrimination values of the δ13C carbon isotope were found. The obtained results show a minor effect of a degree of pollution on the physiological condition B. pendula specimen. On the other hand, mean Bet v1 concentration measured in pollen samples collected in Kraków was significantly higher than in less polluted places (p = .03886), while FT-Raman spectra showed the most distinct variations in the wavenumbers characteristic of proteins. Pollen collected at sites of the increased NOx and PM concentration, show the highest percentage values of potential aggregated forms and antiparallel β-sheets in the expense of α-helix, presenting a substantial impact on chemical compounds of pollen, Bet v1 concentration and on formation of the secondary structure of proteins, what can influence their functions.

Профіль сенсибілізації до алергенних компонентів у пацієнтів з респіраторною алергічною патологією

Abstract. Respiratory allergic diseases, which include allergic rhinitis and bronchial asthma, are a serious medical and social problem worldwide due to their high prevalence and negative impact on the quality of life of the relevant category of patients. The development of respiratory allergy pathology is usually caused by inhaled allergens, which are divided into seasonal: tree, grass or weed pollen, as well as year-round — house dust mites, mold, pet epithelium. But at the same time, respiratory manifestations of allergic pathology are often combined with its non-respiratory manifestations, which affects the profile of sensitization of patients to various allergens and requires a personalized approach to specific allergy diagnostics and immunotherapy. The aim of this study was to study the profile of sensitization to the components of various allergens in patients with respiratory allergic pathology. Materials and methods. The results of a multiplex study (determination of specific IgE to 112 allergenic proteins using the ImmunoCap ISAC test system) in 291 patients who applied to the Clinic of Allergology and Immunology “Forpost” with signs of respiratory allergic pathology were analyzed. Results. Among the seasonal allergens, the most frequent causes of sensitization were spring tree proteins (PR10) — Bet v1, timothy and meadow grasses Phl p1, and ragweed Amb a1. Among year-round allergens, sensitization to the major allergenic component of cats — uteroglobin Fel d1, major components of house dust mites and mold fungi Alternaria alternata was most often detected. Among the allergenic proteins of dogs, sensitization to urinary kallikrein Can f5 was most common. The vast majority of examined patients also had sensitization to food allergens of three main groups of proteins — thermolabile proteins (PR10), lipid transport proteins (LTP), or tropomyosin. Conclusions. In the structure of sensitization among adult patients, the main components of pollen allergens of spring trees (Bet v1), meadow grasses (Phl p1) and ragweed (Amb a1) play an important role. Year-round allergens include cat allergens (Fel d1), house dust mites (Der р1, Der f1, Der p2, Der f2) and Alternaria alternata mold (Alt a1). In patients with hypersensitivity to dog and house dust mite allergens, it is necessary to determine the presence of antibodies to such important components as Can f5 and Der p23. Sensitization to minor components of allergens was detected much less often, however, the appropriate determination of antibodies to them is also important, as it affects the choice of patient treatment tactics. Sensitization to food products in persons with respiratory allergic diseases is due to cross-properties of inhaled and food allergens due to PR10, LTP and tropomyosin molecules.

Причинно-значимые аллергены и спектр сенсибилизации детей, перенесших пищевую анафилаксию

Aim: to assess the spectrum of sensitization and reveal causative allergens in Ekaterinburg children with the clinical history of food-induced anaphylaxis (FIA) for reducing the number of life-threatening food allergy (FA) episodes in these children. Patients and Methods: the study included 60 children — 36 (60.0%) boys and 24 (40.0%) girls aged from 4 months to 16 years who lived in Yekaterinburg. All children had (FIA) episodes in their clinical histories. The children underwent physical examination, and their allergy- focused clinical history was taken. Also, the ISAC-112 ImmunoCAP assay, a multiplex test with allergen components, was used. Results: the sensitization was assessed, and the causative allergens were identified in 100% of cases. In 31 children (51.67%) FIA was initiated by milk proteins (Bos d4, Bos d5, Bos d8); in 10 (16.67%) – chicken egg (Gal d2, Gal d1); in 10 (16.67%) – walnut (Jug r1, Jug r2, Jug r3); in 9 (15.00%) – fish (Gad c1); in 7 (11.67%) – kiwi (Act d1); in 7 (11.67%) – peanut (Ara h1, Ara h2, Ara h3, Ara h6); and in 20 (33%) – by different nuts (Ber e1, Ana o2, Cora 9, Cora 8). Elevated specific immunoglobulin E (sIgE) levels for birch tree allergens (Bet v1) were found in 39 (65.00%) patients, cat allergens (Fel d1, Fel d2, Fel d4) – in 41 (68.33%), dog allergens (Can f1, Can f2, Can f3, Can f5) – in 24 (40.0%), timothy allergens (Phl p1, Phl p4, Phl p5) – in 10 (16.6%), artemisia allergens (Art v1) – in 8 (13.3%), and house dust mites in 2 (3.33%). Respiratory symptoms in sensitized children with FIA developed in 4 of 5 cases. Conclusion: to reduce the number of life-threatening FA episodes in children with FIA it is necessary to reveal and assess the entire spectrum of sensitization, identify the causative allergens and triggers of potential anaphylactic reaction for the further development of an elimination diet and individualized patient management plan. KEYWORDS: food allergy, food-induced anaphylaxis, children, allergens, sensitization. FOR CITATION: Lepeshkova T.S. Causative allergens and sensitization spectrum in children with the history of food-induced anaphylaxis. Russian Medical Inquiry. 2023;7(2):75–80 (in Russ.). DOI: 10.32364/2587-6821-2023-7-2-75-80.

Lipid transfer protein syndrome: How to save a life through careful education

IntroductionLipid transfer proteins (nsLTPs) are ubiquitous allergens. Patients affected by nsLTP syndrome experience symptoms to various plant-derived foods, ranging from local manifestations to anaphylaxis, the critical treatment of which is represented by self-administration of adrenaline. The principle aim of this study is to assess how dietary recommendations influence the occurrence of new and severe cases and if poly-sensitization to different nsLTPs may play a role. We also investigated about the appropriate use of adrenaline auto-injector during the episodes of anaphylaxis. Moreover, we examinated how other features (ie, co-sensitization to profilin and PR-10 and the presence of risk co-factors) affect these events. Materials and methodsWe evaluated 78 patients allergic to nsLTPs, investigating adherence to diet and ability to use the adrenaline auto-injector. Number of sensitization to nsLTPs, co-sensitization to other panallergens, and presence of risk factors for new reactions were also assessed. Diagnosis was based on clinical history and positivity to in vivo and in vitro tests. During the follow-up, compliance, diet modifications, and new reactions were noted, and re-training for the use of epinephrine auto-injector was performed. At the last visit we evaluated the patients’ ability to use the self-injector. ResultsThe whole of fruits belonging to the Rosaceae family emerged as the most frequent culprit foods (28%), followed by walnut (17%), peanut (17%), and hazelnut (10%). At the baseline visit 23% of the patients described the presence of a risk factor during the allergic reaction (mainly nonsteroidal anti-inflammatory drugs [NSAIDs] and exercise). Forty-five percent of the patients reported anaphylactic reactions; no association between the type of food and the severity of the reactions was found. The presence of sensitization to 4 or more nsLTPs was associated to more severe reactions (p < .05; OR 1.67). During the follow-up 38% of the patients experienced at least 1 new allergic reaction: in 79% of them the culprit food was previously tolerated, and in 69% the reaction was an anaphylaxis. Only 47% of the patients showed a proper use of adrenaline auto-injector during the final evaluation, but a significant correlation between periodic education and reduction of the probability of mistakes in the use was reported (p < .05; OR 0.34). Furthermore, an association between co-sensitization to PR-10 (in particular Bet v1) and profilin and less severe symptoms was found, but without a significant odds ratio. ConclusionA careful education aimed to the prevention of new reactions, through dietary restrictions and avoidance of risk co-factors, and to the management of anaphylaxis, through the training for the correct use of adrenaline auto-injector, should be a routine practice in nsLTP syndrome.

Analysis of Protein Sequence Identity, Binding Sites, and 3D Structures Identifies Eight Pollen Species and Ten Fruit Species with High Risk of Cross-Reactive Allergies.

Fruit allergens are proteins from fruits or pollen that cause allergy in humans, an increasing food safety concern worldwide. With the globalization of food trade and changing lifestyles and dietary habits, characterization and identification of these allergens are urgently needed to inform public awareness, diagnosis and treatment of allergies, drug design, as well as food standards and regulations. This study conducted a phylogenetic reconstruction and protein clustering among 60 fruit and pollen allergens from 19 species, and analyzed the clusters, in silico, for cross-reactivity (IgE), 3D protein structure prediction, transmembrane and signal peptides, and conserved domains and motifs. Herein, we wanted to predict the likelihood of their interaction with antibodies, as well as cross-reactivity between the many allergens derived from the same protein families, as the potential for cross-reactivity complicates the management of fruit allergies. Phylogenetic analysis classified the allergens into four clusters. The first cluster (n = 9) comprising pollen allergens showed a high risk of cross-reactivity between eight allergens, with Bet v1 conserved domain, but lacked a transmembrane helix and signal peptide. The second (n = 10) cluster similarly suggested a high risk of cross-reactivity among allergens, with Prolifin conserved domain. However, the group lacked a transmembrane helix and signal peptide. The third (n = 13) and fourth (n = 29) clusters comprised allergens with significant sequence diversity, predicted low risk of cross-reactivity, and showed both a transmembrane helix and signal peptide. These results are critical for treatment and drug design that mostly use transmembrane proteins as targets. The prediction of high risk of cross-reactivity indicates that it may be possible to design a generic drug that will be effective against the wide range of allergens. Therefore, in the past, we may have avoided the array of fruit species if one was allergic to any one member of the cluster.

Impact of pollen exposure and age distribution on diagnostic tests for safe introduction of various nuts in patients with a primary nut allergy

Introduction ( contexte de la recherche ) The performance of nuts skin prick-test (SPT) and specific IgE is known to potentially be altered by the cross-reactivity with pollens. This can result in misguidance for safe introduction of nuts in patients allergic to one or multiple nuts. We sought to evaluate the impact of pollen sensitization related to the patients age and his geographical area under the nuts diagnostic tests performance in patients with a primary nut allergy. We analyzed paraclinical data from a prospective multicenter pan-European study (the Pronuts study) including SPT and specific IgE (whole extract and major allergens) for nuts, sesame seed and pollens (Bet v 1 and Pru p 3) from allergic patients with a primary nut allergy. To analyze the performance of the tests, we made ROC curves using these variables. One hundred and twenty children were enrolled. Sensitization to Bet v 1 and PR-10 nuts components (Ara h 8 and Cor a 1) were more prevalent and significantly higher in Geneva and London than in Spain, whereas sensitization to Pru p 3 and LTP nuts components (Ara h 9, Cor a 8, Jug r 3) were more prevalent and had higher specific IgE levels in Spain. Specific IgE to PR-10s and LTP nuts components were significantly higher in older patients (≥ 6 years) than in younger children. Levels of specific IgE to nuts seed storage proteins tended to be higher in patients ≥ 6 years compared to younger children. Concerning the performance of the diagnostic tests, in children older than 6 years, specific IgE to Ara h 2 performed significantly better than peanut SPT. Similarly, the AUC for SPT to hazelnut was larger in younger children. However, specific IgE to Cor a 9 and Cor a 14 performed better than hazelnut SPT in children older than 6 years of age in Geneva and London, respectively. For cashew and walnut, no clear differences were found between the AUC for SPT, IgE or components based on age categories. For safe introduction of various nuts in patients diagnosed with a primary nut allergy, the diagnostic strategy needs to be adapted to the local pollen exposure, especially in older children, as sensitization to Bet v1 or Pru p3 may lead to false positive IgE or SPT results to various nuts.

Conformational Epitope Prediction of Birch Betv 1 and Hazel Cor A1 Towards B-Cells

Background: White birch and hazel allergens, namely Bet v1 and Cor a1 are known allergens, but their allergen specificity is not yet characterized.&#x0D; Objective: To map the antigenic determinants responsible for IgE binding utilizing in silico modelling and docking of the peptides against IgE antibody.&#x0D; Methods: The antigen sequences were cut into peptides are docked against the IgE antibody and those with the highest docking scores are further studied for the bond interactions. The overlapping sequences of the high score peptides are observed in the whole antigen model to predict their position. The residues at bond interactions also been reported for these overlapping peptide sequences.&#x0D; Results: The validation is done by antigen-antibody docking studies to confirm the predicted epitope. 25% of the world population suffers from allergic rhinitis and 15% of them develop asthma. Conclusion: Negative binding energies of the studied pollen allergens with IgE confirm their allergenicity. Based on the results of overlapping peptides PF 3,4 and PF 16,17 to play a key role in the allergenic response of white birch and Common hazel.

Changes in qualitative and quantitative traits of birch (Betula pendula) pollen allergenic proteins in relation to the pollution contamination

Birch (Betula pendula) pollen causes inhalant allergy in about 20% of human population in Europe, most of which is sensitive to the main birch allergen, Bet v1. The aim of the study was to find out (i) whether and how the analysed birch individuals differ in regard to composition of individual subunits of pollen proteins and to protein content in these subunits; (ii) whether the level of particulate matter relates to concentration of Bet v1 allergen. Study was performed in Southern Poland, in 2017–2019. Pollen material was collected at 20 sites, of highly or less polluted areas. Protein composition was analysed by SDS-PAGE, while the concentration of Bet v1 was evaluated by ELISA. The obtained results were estimated at the background of the particulate matter (PM10) level and the birch pollen seasons in Kraków. The electrophoregrams of pollen samples collected at different sites showed huge differences in staining intensities of individual protein subunits, also among important birch allergens: Bet v1, Bet v2, Bet v6 and Bet v7. The level of Bet v1 was significantly higher in the pollen samples collected at the more polluted sites. While the birch pollen allergenic potential is determined, the both pollen exposure and the content of the main allergenic components should be considered, as factors causing immunological response and clinical symptoms manifestation in sensitive individuals.

Development of a sensitive and stable chemiluminescent immunoassay for detection of birch pollen allergic specific IgE based on recombinant Bet v1 protein

BackgroundQuantitative detection of allergens is of great significance for clarifying the cause, treatment, and prevention of allergy disease. Birch pollen is one of the most common inhalational allergens and Bet v1 is the major component allergen of birch allergen. This study aims to develop a stable and sensitive chemiluminescence immunoassay (CLIA) for the detection of birch pollen allergic specific IgE (sIgE) based on recombinant Bet v1 (rBet v1) protein.MethodsrBet v1 protein was expressed in Escherichia coli and purified. Then rBet v1 was applied to detect sIgE in human serum. The performance of the established CLIA was evaluated and compared with Phadia rBet v1 fluorescence enzyme immunoassay (FEIA) system.ResultsThe developed CLIA for sIgE to rBet v1 detection shows excellent performance. The assay showed a linear range from 0.1 to 100 IU/mL, with a low detection limit of 0.06 IU/mL. A total of 164 samples were evaluated by CLIA and compared with the results of FEIA. The positive, negative, and total coincidence rate was 90.6% (87/96), 91.2% (62/68), and 90.9% (149/164), respectively. The r-value of Spearman's rank correlation analysis was 0.935 (P < 0.001). The use of high levels of bilirubin (50 mg/dL), hemoglobin (400 mg/dL) and lipid (2000 mg/dL) didn't interfere with the results.ConclusionsThe proposed CLIA exhibits excellent performance for the detection of rBet v1 specific IgE. It can be a reliable tool for the early diagnosis of hypersensitivity.

Hazelnut Allergy.

Background and Objectives: Hazelnuts are frequently involved in IgE-mediated reactions and represent the main culprit of nut allergy in Europe. The clinical presentation varies from mild symptoms limited to the oropharynx [oral allergy syndrome (OAS)], due to the cross-reaction with homologues in pollen allergens and more severe events caused by the primary sensitization to highly stable molecules contained in hazelnuts. The aim of this review is to summarize the most relevant concepts in the field of hazelnut allergy and to provide a practical approach useful in the clinical practice Materials and Methods: References were identified by PubMed searches dating from January 2000 up to November 2020 using the search terms: “component resolved diagnosis” and “Hazelnut allergy. Results: The storage proteins Cor a 9 and Cor a 14 resulted highly specific for primary hazelnut allergy and strongly associated with severe reactions, while the cross reactive Cor a 1, an homolog of the birch Bet v1, were related to OAS. Any cut-off has shown a specificity and sensitivity pattern as high as to replace the oral food challenge (OFC), which still remains the gold standard in the diagnosis of hazelnut allergy. To date there is still no definitive treatment. Hazelnut free-diet and treatment of symptoms with emergency management, including the prescription of auto-injective epinephrine, still represent the main approach. Oral allergen immunotherapy (AIT) appears a promising therapeutic strategy and the definition of individual clinical threshold would be useful for sensitized individuals, caregivers, and physicians to reduce social limitation, anxiety, and better manage food allergy. Conclusions: An accurate diagnostic work-up including clinical history, in vivo and in vitro test including component resolved diagnosis and OFC are essential to confirm the diagnosis, to assess the risk of a severe reaction, and to prescribe an adequate diet and treatment.

Оральный аллергический синдром и ангиоотеки в ротовой полости у пациентов с сенсибилизацией к березе: есть ли повышенные риски?

Aim: to study the sensitization profile in patients with sensitivity to Bet v1 allergen who have clinically significant respiratory symptoms of pollinosis during the birch flowering season, oral allergy syndrome (OAS), and angioedema to nuts and stone fruits. Patients and Methods: a prospective open-label study included 40 children (average age 7.52±0.64), 26 (65%) boys and 14 (35%) girls. All children had sensitization to the birch major allergen (Bet v1), symptoms of respiratory allergy during the birch flowering season, manifestations of OAS with angioedema in combination with hives or without it after eating fruits of Rosaceae family/nuts/peanuts. Children underwent general clinical and allergy researches, determination of total IgE and eosinophil cationic protein. By the method of component-resolved diagnosis of allergy (ISAC-112, ImmunoCAP), a comprehensive allergology examination for 112 allergen molecules was performed for each child. Results: the children of the study group were found to have increased values of total IgE (256.66±40.45 IU/mL) and eosinophil cationic protein (67.22±8.67 ng/mL). It was found that 57.5% of children were sensitized to tree nut storage proteins (rJug r1, rJug r2, NCoR a9, rAna o2, rBer e1), and some patients (27.5%) had increased specific IgE to non-specific lipid-transfer proteins (npLTPs) (rPru p3, NCoR a8, rAra h9, rJug r3). Antibodies to peanut storage proteins (rAra h1, rAra h2, rAra h3, rAra h6) were in 22.5% of children in the study group. Conclusion: the component-resolved diagnosis of allergy allows to determine the sensitization profile of patients. Sensitization detection to storage proteins and/or nsLTPs of nuts, peanuts and fruits is a predictor of possible severe allergic reactions. The exclusion of these products, both raw and heat-treated, reduces the number of severe acute allergic reactions in patients and prevents possible fatal outcomes. KEYWORDS: oral allergy syndrome, angioedema, children, birch, sensitization to Bet v1 allergen, storage proteins, nsLTPs. FOR CITATION: Lepeshkova T.S., Beltyukov E.K., Tsarkova S.A., Naumova V.V. Oral allergy syndrome and angioedema in patients with birch allergen sensitization: are there any high risks? Russian Medical Inquiry. 2021;5(1):21–24. DOI: 10.32364/2587-6821-2021-5-1-21-24.

Potential Differences between Local and Systemic Allergic Rhinitis Induced by Birch Pollen

Introduction: Different endotypes of rhinitis are known, but its pathomechanism has not been conclusively established. For example, the precise difference between systemic allergic rhinitis (SAR) and local allergic rhinitis (LAR) is still being checked. Comparison of patients with LAR and with allergies to birch of those with intermittent allergic rhinitis, same allergy, or with non-allergic rhinitis (NAR) was the purpose of this study. Methods: Twenty-six patients with LAR, 18 with SAR and allergy to birch, and 21 with NAR were included. Patients who met the inclusion criteria were selected to undergo the following procedures at baseline: medical examinations, nasal provocation test (NPT), detection of nasal-specific IgE to birch as well as basophil activation test (BAT). All immunological parameters were detected before and after NPT. Results: Concentration of nasal IgE to Bet v1 increased comparably in the LAR and SAR groups after NPT to birch as follows: in 21 (81%) patients with LAR, 14 (78%) with SAR, and in everyone in the NAR group. Serum concentration of allergen-specific IgE to Bet v1 increased significantly from a median of 20.7 (25–75% interval: 11.2–35.6) IU/mL to 29.9 (13.6–44.1) (p = 0.028) after NPT in patients with SAR. Allergen-specific IgE to Bet v1 was absent in all patients with LAR and NAR before and after NPT. BAT with Bet v1 was positive in 22 (85%) patients with LAR, in 14 (78%) with SAR, and 2 (9.5%) with NAR. Conclusion: These obtained data suggest there are no potential mechanisms that could explain LAR compared to SAR.

The Interaction between Antioxidants Content and Allergenic Potency of Different Raspberry Cultivars.

Food allergies are a very serious problem among consumers. The most common food allergies involve animal products, but they can also involve fruits such as berries. We aimed to determine whether organic farming is useful for the production of high-quality and safe fruits. Three varieties of raspberries ‘Laszka’, ‘Glen Ample’ and ‘Polka’ from organic and conventional production (neighboring farms) were collected over the two years of the experiment. Quantitative and qualitative analysis of phenolic compounds was carried out, and the content of Bet v1 and profilin was determined. The organic raspberries contained a lower level of phenolic compounds, especially anthocyanins. Conventional fruits were characterized by a higher allergenic potency than organic ones. We found a strong link between their anthocyanin content and the allergy status of conventional raspberry fruits. Therefore, organically produced raspberries are safer for consumers.

Evaluation of the Potential Allergenicity of Strawberries in Response to Different Farming Practices.

Fruit allergies are a large problem today. Many consumers suffer from food allergies or intolerances. The method of food production has a major impact on its quality. In fruit and vegetable production, three different farming systems are mainly found: conventional, integrated pest management and organic production. The latter is considered the best in terms of fruits and vegetables safety and high quality. The present experiment was performed to demonstrate the effect of the strawberry production method on its allergenic properties and flavonoid content. The strawberry ‘Honeoye’ cv. was used for the study. Fruits from the three cultivation systems, organic, conventional and integrated, were tested for their content of biologically active compounds and their potential allergenicity. The results obtained indicate that the strawberries from the organic system were the safest because they contained the lowest levels of Bet v1 and profilin in comparison with the fruits from the integrated and conventional systems.