Granulocytes and mast cells in AllergoOncology-Bridging allergy to cancer: An EAACI position paper.

Derived from the myeloid lineage, granulocytes, including basophils, eosinophils, and neutrophils, along with mast cells, play important, often disparate, roles across the allergic disease spectrum. While these cells and their mediators are commonly associated with allergic inflammation, they also exhibit several functions either promoting or restricting tumor growth. In this Position Paper we discuss common granulocyte and mast cell features relating to immunomodulatory functions in allergy and in cancer. We highlight key mechanisms which may inform cancer treatment and propose pertinent areas for future research. We suggest areas where understanding the communication between granulocytes, mast cells, and the tumor microenvironment, will be crucial for identifying immune mechanisms that may be harnessed to counteract tumor development. For example, a comprehensive understanding of allergic and immune factors driving distinct neutrophil states and those mechanisms that link mast cells with immunotherapy resistance, might enable targeted manipulation of specific subpopulations, leading to precision immunotherapy in cancer. We recommend specific areas of investigation in AllergoOncology and knowledge exchange across disease contexts to uncover pertinent reciprocal functions in allergy and cancer and allow therapeutic manipulation of these powerful cell populations. These will help address the unmet needs in stratifying and managing patients with allergic diseases and cancer.

AllergoOncology: Biomarkers and refined classification for research in the allergy and glioma nexus-A joint EAACI-EANO position paper.

Epidemiological studies have explored the relationship between allergic diseases and cancer risk or prognosis in AllergoOncology. Some studies suggest an inverse association, but uncertainties remain, including in IgE-mediated diseases and glioma. Allergic disease stems from a Th2-biased immune response to allergens in predisposed atopic individuals. Allergic disorders vary in phenotype, genotype and endotype, affecting their pathophysiology. Beyond clinical manifestation and commonly used clinical markers, there is ongoing research to identify novel biomarkers for allergy diagnosis, monitoring, severity assessment and treatment. Gliomas, the most common and diverse brain tumours, have in parallel undergone changes in classification over time, with specific molecular biomarkers defining glioma subtypes. Gliomas exhibit a complex tumour-immune interphase and distinct immune microenvironment features. Immunotherapy and targeted therapy hold promise for primary brain tumour treatment, but require more specific and effective approaches. Animal studies indicate allergic airway inflammation may delay glioma progression. This collaborative European Academy of Allergy and Clinical Immunology (EAACI) and European Association of Neuro-Oncology (EANO) Position Paper summarizes recent advances and emerging biomarkers for refined allergy and adult-type diffuse glioma classification to inform future epidemiological and clinical studies. Future research is needed to enhance our understanding of immune-glioma interactions to ultimately improve patient prognosis and survival.

Legume Allergens Pea, Chickpea, Lentil, Lupine and Beyond.

PURPOSE OF THE REVIEW: In the last decade, an increasing trend towards a supposedly healthier vegan diet could be observed. However, recently, more cases of allergic reactions to plants and plant-based products such as meat-substitution products, which are often prepared with legumes, were reported. Here, we provide the current knowledge on legume allergen sources and the respective single allergens. We answer the question of which legumes beside the well-known food allergen sources peanut and soybean should be considered for diagnostic and therapeutic measures. RECENT FINDINGS: These "non-priority" legumes, including beans, pea, lentils, chickpea, lupine, cowpea, pigeon pea, and fenugreek, are potentially new important allergen sources, causing mild-to-severe allergic reactions. Severe reactions have been described particularly for peas and lupine. An interesting aspect is the connection between anaphylactic reactions and exercise (food-dependent exercise-induced anaphylaxis), which has only recently been highlighted for legumes such as soybean, lentils and chickpea. Most allergic reactions derive from IgE cross-reactions to homologous proteins, for example between peanut and lupine, which is of particular importance for peanut-allergic individuals ignorant to these cross-reactions. From our findings we conclude that there is a need for large-scale studies that are geographically distinctive because most studies are case reports, and geographic differences of allergic diseases towards these legumes have already been discovered for well-known "Big 9" allergen sources such as peanut and soybean. Furthermore, the review illustrates the need for a better molecular diagnostic for these emerging non-priority allergen sources to evaluate IgE cross-reactivities to known allergens and identify true allergic reactions.

Specific IgE against the house dust mite allergens Der p 5, 20 and 21 influences the phenotype and severity of atopic diseases.

BACKGROUND: House dust mites (HDM) are among the most important sources for airborne allergens with high relevance for atopic diseases. Routine tests contain only 4 of 32 registered allergens of Dermatophagoides pteronyssinus. Clinical relevance and pathomechanistic properties of many allergens are not well understood. OBJECTIVE: The association of several HDM allergens with allergic rhinitis, allergic asthma, and atopic dermatitis was investigated to identify allergens with biomarker potential and to transfer them into diagnostics. METHODS: Eight out of nine D. pteronyssinus allergens (nDer p 1, rDer p 2, rDer p 5, rDer p 7, rDer p 10, rDer p 13, rDer p 20, rDer p 21, rDer p 23) were recombinantly expressed and purified. Sensitization patterns of 384 HDM-allergic individuals exhibiting different clinical phenotypes were analyzed with a serum-saving multiplex array. RESULTS: Sensitization to more than three mite allergens (sensitization count) was associated with allergic asthma and/or atopic dermatitis. Reactions to Der p 5 and Der p 21 were more frequent in allergic asthma compared to allergic rhinitis. Atopic dermatitis patients were more often sensitized to Der p 5, Der p 20, and Der p 21 among others. Der p 20-IgE > 80 kU/L was associated with severe atopic dermatitis in 75% of patients. CONCLUSION: This study demonstrates the clinical importance of the sensitization count and of certain allergens (Der p 5, Der p 20, and Der p 21) not available for routine diagnostics yet. Implementing them as well as the sensitization count in diagnostic measures will improve diagnosis and risk assessment of HDM-allergic patients.

EAACI Molecular Allergology User's Guide 2.0.

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

Innovative robust basophil activation test using a novel gating strategy reliably diagnosing allergy with full automation.

BACKGROUND: Allergy is one of the most common chronic diseases in Europe. Therefore, an increased need for specific and sensitive diagnostic tests that truly detect allergy exists. This study aimed at establishing a highly specific high-throughput and automated basophil activation test (BAT) that proves the existence of an allergy with utmost probability. METHODS: BAT from 1104 samples was analyzed; a novel gating strategy with three antibodies (FcεRIα, CD203c, CD63) was established and compared with our published protocol (12 antibodies). Based on the novel gating strategy, storage conditions, automated measurement, and analyses using R (1376 samples out of 1389) were optimized to set up a high-throughput BAT. RESULTS: No differences in sensitivity and specificity were found between the novel three antibody (FcεRIα, CD203c, CD63) and the 12 antibody gating strategy or between automated and manually analyzed samples (saving up to 90% of labor time). The time frame for basophil activation measurement after blood donation has been extended considerably (whole blood storage ≤7 days (RT) and 17 days (4°C) prior to BAT preparation and measurement). Respective storage conditions were optimized for samples after stimulation, staining, and preparation (≤7 days (RT) and 28 days (4°C)). These achievements were confirmed by a nationwide ring trial showing robustness and applicability of our BAT on a variety of flow cytometers. CONCLUSION: Our considerable optimizations overcame the hurdles that until now prevented the BAT from being used as high-throughput allergy diagnostic test in routine laboratories and shall allow for collaborative studies between clinics and research centers.

Carbohydrate epitopes currently recognized as targets for IgE antibodies.

Until recently, glycan epitopes have not been documented by the WHO/IUIS Allergen Nomenclature Sub-Committee. This was in part due to scarce or incomplete information on these oligosaccharides, but also due to the widely held opinion that IgE to these epitopes had little or no relevance to allergic symptoms. Most IgE-binding glycans recognized up to 2008 were considered to be "classical" cross-reactive carbohydrate determinants (CCD) that occur in insects, some helminths and throughout the plant kingdom. Since 2008, the prevailing opinion on lack of clinical relevance of IgE-binding glycans has been subject to a reevaluation. This was because IgE specific for the mammalian disaccharide galactose-alpha-1,3-galactose (alpha-gal) was identified as a cause of delayed anaphylaxis to mammalian meat in the United States, an observation that has been confirmed by allergists in many parts of the world. Several experimental studies have shown that oligosaccharides with one or more terminal alpha-gal epitopes can be attached as a hapten to many different mammalian proteins or lipids. The classical CCDs also behave like haptens since they can be expressed on proteins from multiple species. This is the explanation for extensive in vitro cross-reactivity related to CCDs. Because of these developments, the Allergen Nomenclature Sub-Committee recently decided to include glycans as potentially allergenic epitopes in an adjunct section of its website (www.allergen.org). In this article, the features of the main glycan groups known to be involved in IgE recognition are revisited, and their characteristic structural, functional, and clinical features are discussed.

Combination of immunotherapies for severe allergic asthma.

INTRODUCTION: Difficult-to-treat or severe persistent asthma accounts for 5-10% of the asthma population worldwide. However, this group of patients creates a higher burden on health systems due to their morbidity and need for long-term and additional treatment. Biological drugs constitute an alternative therapy in the treatment of patients with refractory asthma. In cases where inhalant allergy is part of the pathomechanism, allergen-specific immunotherapy (SIT) is a causative treatment option for allergic asthma. However, SIT is contraindicated for uncontrolled asthma and cannot be administered according to the guidelines. This is due to the risk of further worsening of uncontrolled asthma during treatment. CASE STUDY: We herein report a case of a 67-year-old male with severe allergic asthma who was successfully treated with SIT after asthma control was achieved by using target treatments. RESULTS: Complete control of asthma was achieved, and SIT with allergens from early flowering trees (birch-alder-hazel) was administered. Further, no asthmatic exacerbations or decrease in respiratory function occurred during the 15 months of treatment with mepoluzimab. He did not need any oral glucocorticosteroids. CONCLUSION: The case report presented here suggests the effectiveness of an individualized approach and phenotype-specific treatment of patients who cannot receive allergen-specific immunotherapy due to the contraindication uncontrolled asthma and who receive SIT after asthma control is achieved by using target treatments.

Effect of comorbid pulmonary disease on the severity of COVID-19: A systematic review and meta-analysis.

Coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory syndrome coronavirus 2 was first detected in Wuhan, China, in late 2019 and continues to spread worldwide. Persistent questions remain about the relationship between the severity of COVID-19 and comorbid diseases, as well as other chronic pulmonary conditions. In this systematic review and meta-analysis, we aimed to examine in detail whether the underlying chronic obstructive pulmonary diseases (COPD), asthma and chronic respiratory diseases (CRDs) were associated with an increased risk of more severe COVID-19. A comprehensive literature search was performed using five international search engines. In the initial search, 722 articles were identified. After eliminating duplicate records and further consideration of eligibility criteria, 53 studies with 658,073 patients were included in the final analysis. COPD was present in 5.2% (2191/42,373) of patients with severe COVID-19 and in 1.4% (4203/306,151) of patients with non-severe COVID-19 (random-effects model; OR = 2.58, 95% CI = 1.99-3.34, Z = 7.15, p < 0.001). CRD was present in 8.6% (3780/44,041) of patients with severe COVID-19 and in 5.7% (16,057/280,447) of patients with non-severe COVID-19 (random-effects model; OR = 2.14, 95% CI = 1.74-2.64, Z = 7.1, p < 0.001). Asthma was present in 2.3% (1873/81,319) of patients with severe COVID-19 and in 2.2% (11,796/538,737) of patients with non-severe COVID-19 (random-effects model; OR = 1.13, 95% CI = 0.79-1.60, Z = 0.66, p = 0.50). In conclusion, comorbid COPD and CRD were clearly associated with a higher severity of COVID-19; however, no association between asthma and severe COVID-19 was identified.

On the cause and consequences of IgE to galactose-α-1,3-galactose: A report from the National Institute of Allergy and Infectious Diseases Workshop on Understanding IgE-Mediated Mammalian Meat Allergy.

The mammalian meat allergy known as the "α-Gal syndrome" relates to IgE specific for galactose-α-1,3-galactose (α-Gal), an oligosaccharide that is present in cells and tissues of nonprimate mammals. The recognition of delayed reactions to food derived from mammals in patients with IgE to α-Gal and also the association with tick bites have been increasing worldwide. In 2018, the National Institute of Allergy and Infectious Diseases, Division of Allergy, Immunology and Transplantation, sponsored a workshop on this emerging tick-related disease. International experts from the fields of tick biology, allergy, immunology, infectious disease, and dermatology discussed the current state of our understanding of this emerging medical condition. The participants provided suggestions for specific research priorities and for the development of resources to advance our knowledge of the mechanisms, diagnosis, management, and prevention of this allergic disease. This publication is a summary of the workshop and the panel's recommendations are presented herein.

Identification of Seasonal Variations of Antibodies against PR-10-Specific Epitopes Can Be Improved Using Peptide-Phage Display.

BACKGROUND: In pollinosis patients, allergen-specific antibody titers show seasonal variations. Little is known about these variations at the epitope level. OBJECTIVES: We aimed at investigating seasonal variations on the level of allergen epitope recognition in patients with Bet v 1-related food allergy using a peptide phage display approach. METHODS: Serum samples collected over 1 year from 4 patients of the placebo arm of the birch-associated soya allergy immunotherapy trial were included. To identify epitopes from Bet v 1-related food allergens, patient sera were used in peptide phage display experiments. In silico analysis of enriched allergen-related motifs was performed. RESULTS: We identified epitope motifs related to Bet v 1 and its homologs in soya and hazelnut (Gly m 4 and Cor a 1, respectively) that were enriched in accordance with birch and hazel pollen exposure. Within several weeks after the birch pollen season peak, the pattern of identified epitope motifs differed considerably among patients. Data for amino acid preferences in homologous Bet v 1 and Cor a 1 epitope motifs identified for one of the investigated patients suggest changes in concentration or specificity of serum antibodies for the Cor a 1 epitope motif. CONCLUSIONS: Peptide phage display data suggest an impact of birch and hazel pollen exposure on the recognition pattern of Bet v 1-like allergen epitopes. Epitope-oriented analyses could provide deeper, personalized details regarding the allergen epitope recognition influenced by pollen exposure beyond the capability of current methods.

Hypersensitivity reactions to biologics (part I): allergy as an important differential diagnosis in complex immune-derived adverse events.

Purpose: Biotechnological substances (BSs) are strongly relied upon to prevent rejection of transplanted organs, and to treat oncological, allergological, and other inflammatory diseases. Allergic reactions to partly foreign biologics can occur due to their potential immunogenicity. The severity of an immune response to a biological drug may range from no clinical significance to a severe, life-threatening anaphylactic reaction.Methods: Detailed searches were performed on Pubmed, Web of Science, and Google Scholar to include all available publications. In addition, the Food and Drug Administration, the European Medicines Agency, and British Columbia Cancer Agency Drug Manual databases were screened for hypersensitivity reaction (HSR), infusion reaction, injection site reaction, urticaria, and anaphylaxis for individual BSs.Results: Treatment with BSs can cause various types of HSR. These are mentioned in the literature with definitions such as allergic reactions, anaphylactoid reactions, anaphylaxis, HSR, infusion reactions, injection site reactions, cytokine release syndrome, and urticaria. Due to the overlap in signs and symptoms in the reported descriptions, it is not always possible to differentiate these reactions properly according to their pathomechanism. Similarly, many data reported as anaphylaxis actually describe severe anaphylactic reactions (grades III or IV).Conclusion: There is an urgent need for a simpler symptom- or system-based classification and scoring system to create an awareness for HSRs to BSs. A better understanding of the pathophysiology of HSRs and increased clinical experience in the treatment of side effects will provide timely control of unexpected reactions. As a result, immunotherapy with BSs will become safer in the future.Cite this as Gülsen A, Wedi B, Jappe U. Hypersensitivity reactions to biologics (part I): allergy as an important differential diagnosis in complex immune-derived adverse events. Allergo J Int 2020; 29:97-125https://doi.org/10.1007/s40629-020-00126-6.

Glycans and glycan-specific IgE in clinical and molecular allergology: Sensitization, diagnostics, and clinical symptoms.

Glycan-specific IgE antibodies cross-react with highly similar or even identical carbohydrate structures on a variety of different natural allergens, the so-called cross-reactive carbohydrate determinants (CCDs). In clinical practice CCDs often interfere with the specificity of in vitro allergy diagnostics, thus impairing allergy therapy decisions for individual patients. Strikingly, these IgE antibodies directed against CCDs often do not cause clinically relevant allergy symptoms. On the other hand, the IgE-binding glycan allergen galactose-α-(1,3)-galactose (α-Gal) is associated with IgE-mediated delayed anaphylaxis in meat allergy. The reason for this discrepancy is not known. The discovery of α-Gal stimulated new discussions and investigations regarding the relevance of anti-glycan IgE for allergic diseases. In this review the effect of glycans and glycan-specific IgE on sensitization to allergens and allergy diagnosis is described. Because parasite infections elicit a similar immunologic environment as allergic diseases, the association of glycan-specific antibodies against parasite glycoproteins with glycan structures on allergens is discussed.

Peanut oleosins associated with severe peanut allergy-importance of lipophilic allergens for comprehensive allergy diagnostics.

BACKGROUND: Peanut allergy is one of the most common and most severe food allergies in Western countries and its accurate diagnosis to prevent potential life-threatening allergic reactions is crucial. However, aqueous extracts used for routine diagnostic measurements are devoid of lipophilic allergens such as oleosins. We have recently succeeded in the isolation and purification of these unique proteins, and the present study evaluates their allergenic potential and clinical relevance. OBJECTIVE: We sought to assess allergenicity and sensitization prevalence of oleosins obtained from both raw and in-shell roasted peanuts. In addition, we tested the utilization of natural and recombinant oleosins for allergy diagnostic purposes. METHODS: Oleosin sensitization, prevalence, and impact of thermal processing were analyzed by immunoblot with sera from 52 peanut-allergic individuals displaying different clinical phenotypes. The application of natural and recombinant oleosins for allergy diagnostics was investigated by basophil activation test (BAT). IgE-binding epitopes were identified by oligopeptide microarray. RESULTS: Sensitization to oleosins was observed exclusively in peanut-allergic subjects suffering from severe systemic reactions. IgE-binding capacity of oleosins derived from in-shell roasted peanuts was increased as shown by immunoblot analysis and BAT. Both natural and recombinant molecules can be used to identify oleosin-sensitized patients by BAT. A linear epitope of Ara h 15 was determined that displays high similarity to other seed-derived oleosins. CONCLUSIONS: Oleosins are clinically relevant peanut allergens and most likely associated with severe allergic symptoms. In-shell roasting increases their allergenicity, which is consistent with the observation that most allergic reactions are in connection with roasted peanuts.

Detection of the Peanut Allergens Ara h 2 and Ara h 6 in Human Breast Milk: Development of 2 Sensitive and Specific Sandwich ELISA Assays.

BACKGROUND: Little is known about breast milk as a vehicle for tolerance development or sensitization to peanuts very early in life. Thus, well-characterized and highly sensitive detection systems for the reliable determination of peanut allergens in breast milk are mandatory. METHODS: For the quantification of the marker allergens Ara h 2 and Ara h 6 in the low nanogram per milliliter range in breast milk samples of a German cohort, sensitive and highly specific sandwich ELISAs were optimized and validated. RESULTS: The Ara h 2 ELISA revealed a limit of detection (LOD) of 1.3 ng Ara h 2/mL and a quantification range of 2.3-250 ng/mL, the Ara h 6 ELISA showed an LOD of 0.7 ng/mL and a working range of 1.1-14.4 ng/mL. The assays showed no relevant cross-reactivity against other potentially cross-reactive legume, seed, and tree nut extracts (<0.01%, except for Ara h 1 in the Ara h 2 ELISA <0.1%). Ara h 2 was detectable in breast milk samples from 14/40 (35%) of the participants in concentrations from 2.3 to 184 ng/mL, Ara h 6 appeared in 9/40 (22.5%) of the lactating mothers between 1.1 and 9.7 ng/mL, and 1 highly positive sample with 79 ng/mL. Both allergens appeared at the same time points, but Ara h 6 in lower concentrations than Ara h 2. CONCLUSIONS: Sensitive and specific diagnostic tools for the determination of Ara h 2 and Ara h 6 in human breast milk were established. The kinetics of secreted Ara h 2 and Ara h 6 seem to be similar but with a difference in concentration. Follow-up investigations on their tolerogenic or sensitizing properties in breast milk become now accessible.

Relevance of Lipophilic Allergens in Food Allergy Diagnosis.

PURPOSE OF REVIEW: The purpose of this review is to provide available data on a new class of allergens, the oleosins, and their diagnostic value. There is evidence that allergen extracts used for in vivo as well as in vitro diagnostic tests do not contain oleosins because these proteins are lipophilic and nearly insoluble in saline or aqueous solutions. So far, only oleosins of peanut, sesame and hazelnut have been registered as allergens. Reports on IgE-binding tests performed with oleosins of different species with sera from allergic patients show that IgE specific for oleosins are associated with severe allergic reactions which is why they should be part of the diagnostic tests in the future. RECENT FINDINGS: Recent findings showed that oleosins purified from in shell-roasted peanuts revealed a higher IgE-binding capacity when compared to raw ones. Naturally purified as well as recombinantly produced peanut oleosins can be used in basophil activation test. The synopsis of all reports on different thermal processing of several oleosin sources and the respective data obtained with patients sera investigated via immunoblot and basophil activation test points to the recommendation that-if naturally purified oleosins are used, they should mostly be obtained from roasted food allergen sources. For immunoblot and basophil activation test, both, naturally purified oleosins as well as recombinant modified oleosins are valuable diagnostic tools.

[Molecular-allergological aspects of allergen-specific immunotherapy]. / Molekular-allergologische Aspekte der allergenspezifischen Immuntherapie.

Allergen-specific immunotherapy (SIT) does not achieve 100% efficacy, nor is there a reliable marker for therapy failure. However, advances in molecular allergology over the past few years have allowed a significantly improved characterization of the patients using molecular-allergological analysis methods (molecular phenotyping). Thus, major and minor allergens can be identified. In addition, the marker allergens for the severity of an allergic reaction, the pathological and therapeutic predictive marker allergens, and sensitization patterns are identified.