Mast cell activation tests by flow cytometry: A new diagnostic asset?

Pediatric idiopathic anaphylaxis: practical management from infants to adolescents

Idiopathic anaphylaxis (IA) remains a frustrating challenge for both patients and physicians. The aim of this paper is to focus on IA in pediatric ages and suggest possible diagnostic algorithms according to specific age ranges (infants, children, and adolescents). In fact, in a variable percentage of patients, despite extensive diagnostic tests, the cause of anaphylactic episodes cannot be identified. Moreover, the lack of a unanimous IA definition requires a careful and detailed diagnostic workup. Prompt recognition of signs and symptoms, especially in younger children, and an accurate clinical history often allow a choice of the most appropriate diagnostic tests and a correct differential diagnosis.

IgE-Mediated Cannabis Allergy and Cross-Reactivity Syndromes: A Roadmap for Correct Diagnosis and Management

PURPOSE OF THE REVIEW

With increased access and decriminalization of cannabis use, cases of IgE-dependent cannabis allergy (CA) and cross-reactivity syndromes have been increasingly reported. However, the exact prevalence of cannabis allergy and associated cross-reactive food syndromes (CAFS) remains unknown and is likely to be underestimated due to a lack of awareness and insufficient knowledge of the subject among health care professionals. Therefore, this practical roadmap aims to familiarize the reader with the early recognition and correct management of IgE-dependent cannabis-related allergies. In order to understand the mechanisms underlying these cross-reactivity syndromes and to enable personalized diagnosis and management, special attention is given to the molecular diagnosis of cannabis-related allergies.

RECENT FINDINGS

The predominant signs and symptoms of CA are rhinoconjunctivitis and contact urticaria/angioedema. However, CA can also present as a life-threatening condition. In addition, many patients with CA also have distinct cross-reactivity syndromes, mainly involving fruits, vegetables, nuts and cereals. At present, five allergenic components of Cannabis sativa (Can s); Can s 2 (profilin), Can s 3 (a non-specific lipid protein), Can s 4 (oxygen-evolving enhancer protein 2 oxygen), Can s 5 (the Bet v 1 homologue) and Can s 7 (thaumatin-like protein) have been characterized and indexed in the WHO International Union of Immunological Sciences (IUIS) allergen database. However, neither of them is currently readily available for diagnosis, which generally starts by testing crude extracts of native allergens. The road to a clear understanding of CA and the associated cross-reactive food syndromes (CAFS) is still long and winding, but well worth further exploration.

Combinatorial Genomic Biomarkers Associated with High Response in IgE-Dependent Degranulation in Human Mast Cells

Mast cells are the major effector cells that mediate IgE-dependent allergic reactions. We sought to use integrated network analysis to identify genomic biomarkers associated with high response in IgE-mediated activation of primary human mast cells. Primary human mast cell cultures derived from 262 normal donors were categorized into High, Average and Low responder groups according to their activation response profiles. Transcriptome analysis was used to identify genes that were differentially expressed in different responder cultures in their baseline conditions, and the data were analyzed by constructing a personalized perturbed profile (PEEP). For upregulated genes, the construction of PEEP for each individual sample of all three responder groups revealed that High responders exhibited a higher percentage of "perturbed" samples whose PEEP values lay outside the normal range of expression. Moreover, the integration of PEEP of four selected upregulated genes into distinct sets of combinatorial profiles demonstrated that the specific pattern of upregulated expression of these four genes, in a tandem combination, was observed exclusively among the High responders. In conclusion, this combinatorial approach was useful in identifying a set of genomic biomarkers that are associated with high degranulation response in human mast cell cultures derived from the blood of a cohort of normal donors.

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.

Treatment of Allergies to Fur Animals

Allergy to fur animals is becoming an increasingly common clinical problem in everyday medical practice. Depending on the route of exposure to the allergen, patients present with many, often non-specific symptoms. The most common illnesses among people with allergies to the above-mentioned allergens are as follows: allergic rhinitis, allergic conjunctivitis, atopic bronchial asthma, food allergy, allergic contact dermatitis, and sometimes anaphylactic shock. In recent years, there has been a change in the holistic approach to the treatment of allergy patients. The method of treatment should be tailored to a specific patient, taking into account his or her predispositions, economic possibilities, and therapeutic goals. The article describes the main methods of treating allergies, focusing primarily on allergies to fur animals. Allergy treatment always requires great care, and qualification for specific types of therapy should be preceded by a thorough and accurate diagnosis.

Mast cell versus basophil activation test in allergy: Current status

In the past two decades, we witnessed the evolution of the basophil activation test (BAT) from mainly research applications to a potential complementary diagnostic tool to document IgE-dependent allergies. However, BAT presents some technical weaknesses. Around 10%-15% of tested patients are non-responders, BAT can be negative immediately post-reaction and the use of fresh basophils, ideally analysed within 4 h of collection, restricts the number of tests that can be performed per sample. The need for fresh basophils is especially limiting when conducting batch analyses and interlaboratory comparisons to harmonize BAT methodology. These limitations significantly hinder the wider application of BAT and urge the development of alternative testing, such as the mast cell activation test (MAT). The essential difference between BAT and MAT is the heterogeneity of the starting material used to perform the assays. Mast cells are tissue-resident, so cannot be easily accessed. Current alternative sources for functional studies are generating primary human mast cells, differentiated from donor progenitor cells, or using immortalized mast cell lines. Hence, the methodological approaches for MAT are not only vastly different from BAT, but also different among MAT protocols. This review summarizes the advantages and disadvantages of BAT and MAT assays, dedicating special attention to elucidating the key differences between the cellular sources used and provides an overview of studies hitherto performed comparing BAT and MAT in the diagnosis of IgE-mediated food and drug allergies.

Diagnostics of Allergy to Furry Animals-Possibilities in 2024

Diagnosing allergies is not always easy. Sometimes the symptoms reported by the patient do not match the results of diagnostic tests. Diagnostics of IgE-dependent allergy, including allergy to furry animals, can be based on two basic strategies, "BOTTOM-UP" and "TOP-DOWN", and almost all available allergy tests can be used ranging from skin tests, through specific IgE, to molecular panels and challenge tests. Currently, most information regarding the diagnosis and incidence of allergies to furry animals focuses almost exclusively on the two most common pets-dogs and cats. This is certainly due to the fact that allergy to cats and/or dogs is a common phenomenon, has a huge impact on quality of life, and is a challenge for doctors of many specialties. However, the growing number of owners of other pet species means that diagnostic methods must keep up with the changing needs of patients. Further research in these groups will certainly provide new facts and facilitate clinical decision-making when working with allergic patients.

Perioperative Anaphylaxis in Japanese Secondary Care Institutions: Incidence, Causes, and the Imperative for Improved Diagnostic Practices

Background This research investigates the incidence, suspected causes, and diagnostic procedures for perioperative anaphylaxis (POA), a potentially severe complication, in secondary care hospitals across Japan. Methodology We surveyed Saiseikai hospitals and gathered data on surgical procedures, POA occurrences, potential triggers, and diagnostic methods. Results Among 70,523 surgeries, seven were associated with POA, resulting in an approximate incidence rate of 0.01%. Rocuronium was the most commonly suspected trigger, followed by sugammadex, latex, and angiography contrast agents. Despite the importance of skin tests as the most basic and crucial diagnostic method, they were conducted in only three instances. No in vitro tests for drug identification were conducted, and in four cases, the cause was determined merely based on the timing of drug administration, indicating significant diagnostic limitations. Conclusions The study underscores the critical situation in Japan regarding insufficient diagnostic practices and difficulties in identifying triggering drugs rather than the consistent prevalence of POA in secondary care facilities. The findings emphasize the need for improved diagnostic proficiency and more rigorous drug identification practices to ensure prompt and accurate POA diagnosis. It is essential to conduct further research and interventions to increase patient safety during the perioperative period in secondary care settings.

Comparison of the passive mast cell activation test with the basophil activation test for diagnosis of perioperative rocuronium hypersensitivity

BACKGROUND

Rocuronium is a major cause of perioperative hypersensitivity (POH). Skin tests (STs) and quantification of specific immunoglobulin E antibodies (sIgEs) can yield incongruent results. In such difficult cases, the basophil activation test (BAT) can be helpful. Here, we evaluated the passive mast cell activation test (pMAT) as a substitute of BAT as part of the diagnostic tests for rocuronium allergy.

METHODS

Sera from patients with a suspected POH reaction potentially related to rocuronium were included. All patients had a complete diagnostic investigation, including STs, quantification of sIgEs to morphine and rocuronium, and BAT. For execution of pMAT, human mast cells were generated from healthy donor peripheral blood CD34+ progenitor cells and sensitised overnight with patient sera.

RESULTS

In total, 90 sera were studied: 41 from ST+sIgE+ patients, 13 from ST-sIgE- patients, 20 from ST+sIgE- patients, and 16 from ST-sIgE+ patients. According to BAT results, patients were further allocated into subgroups. Of the 38 BAT+ patients, 25 (66%) showed a positive pMAT as well. Of the 44 BAT- patients, 43 (98%) also showed a negative pMAT. Mast cells that were not passively sensitised did not respond to rocuronium.

CONCLUSIONS

We show that the pMAT, in many cases, can substitute for BAT in the diagnosis of rocuronium hypersensitivity and advance diagnosis in difficult cases with uncertain ST or sIgE results when BAT is not locally available.

Mast Cells as a Target-A Comprehensive Review of Recent Therapeutic Approaches

Mast cells (MCs) are the immune cells distributed throughout nearly all tissues, mainly in the skin, near blood vessels and lymph vessels, nerves, lungs, and the intestines. Although MCs are essential to the healthy immune response, their overactivity and pathological states can lead to numerous health hazards. The side effect of mast cell activity is usually caused by degranulation. It can be triggered by immunological factors, such as immunoglobulins, lymphocytes, or antigen-antibody complexes, and non-immune factors, such as radiation and pathogens. An intensive reaction of mast cells can even lead to anaphylaxis, one of the most life-threatening allergic reactions. What is more, mast cells play a role in the tumor microenvironment by modulating various events of tumor biology, such as cell proliferation and survival, angiogenesis, invasiveness, and metastasis. The mechanisms of the mast cell actions are still poorly understood, making it difficult to develop therapies for their pathological condition. This review focuses on the possible therapies targeting mast cell degranulation, anaphylaxis, and MC-derived tumors.

Immediate hypersensitivity reactions to antineoplastic agents - A practical guide for the oncologist

Immediate hypersensitivity reactions (IHRs) to antineoplastic agents occur frequently, and every oncologist will encounter these reactions in their clinical practice at some point. The clinical signature of IHRs can range from mild to life-threatening, and their occurrence can substantially impede the treatment course of patients with cancer. Yet, clear guidelines regarding the diagnosis and management are scarce, especially from an oncologic point of view. Therefore, herein, we review the definition, pathophysiology, epidemiology, diagnosis and management of IHRs to chemotherapeutic agents and monoclonal antibodies. First, we focus on defining the specific entities that comprise IHRs and discuss their underlying mechanisms. Then, we summarize the epidemiology for the antineoplastic agents that represent the most common causes of IHRs, i.e., platinum compounds, taxanes and monoclonal antibodies (mAbs). Next, we describe the possible clinical pictures and the comprehensive diagnostic work-up that should be executed to identify the culprit and safe alternatives for the future. Finally, we finish with reviewing the treatment options in both the acute phase and after recovery, with the aim to improve the oncologic care of patients with cancer.

A review of cannabis allergy in the early days of legalization

Cannabis allergy is a burgeoning field; consequently, research is still in its infancy and allergists' knowledge surrounding this topic is limited. As cannabis legalization expands across the world, it is anticipated that there will be an increase in cannabis use. Thus, we hypothesize that a concomitant rise in the incidence of allergy to this plant can be expected. Initiatives aimed at properly educating health care professionals are therefore necessary. This review presents the most up-to-date information on a broad range of topics related to cannabis allergy. Although the clinical features of cannabis allergy are becoming more well described and recognized, the tools available to make a correct diagnosis are meager and often poorly accessible. In addition, research on cannabis allergy is still taking its first steps, and new and potentially groundbreaking findings in this field are expected to occur in the next few years. Finally, although therapeutic approaches are being developed, patient and physician education regarding cannabis allergy is certainly needed.

A quarter of a century fundamental and translational research in perioperative hypersensitivity and anaphylaxis at the Antwerp university hospital, a Belgian Centre of Excellence of the World Allergy Organization

Perioperative hypersensitivity constitutes an important health issue, with potential dramatic consequences of diagnostic mistakes. However, safe and correct diagnosis is not always straightforward, mainly because of the application of incorrect nomenclature, absence of easy accessible in-vitro/ex-vivo tests and uncertainties associated with the non-irritating skin test concentrations. In this editorial we summarize the time line, seminal findings, and major realizations of 25 years of research on the mechanisms, diagnosis, and management of perioperative hypersensitivity.

Neuromuscular blocking agent induced hypersensitivity reaction exploration: an update

Acute hypersensitivity reactions (AHRs) occurring in present-day anaesthesia can have severe, sometimes fatal, consequences and their incidence is increasing. The most frequent allergens responsible for AHR during anaesthesia are neuromuscular blocking agents (NMBAs) (70% of the cases) followed by antibiotics (18%), patent blue dye and methylene blue dye (5%), and latex (5%). Following an AHR, strategies for subsequent anaesthetic procedures (especially the choice of an NMBA) may be difficult to formulate due to inconclusive diagnostic analysis in up to 30% of AHRs. Current diagnosis of AHR relies on the detection of mast cell degranulation products and drug-specific type E immunoglobulins (IgE) in order to document an IgE-mediated anaphylaxis (IgE endotype). Nonetheless, other IgE-independent pathways can be involved in AHR, but their detection is not currently available in standard situations. The different mechanisms (endotypes) involved in peri-operative AHR may contribute to the inconclusive diagnostic work-up and this generates uncertainty concerning the culpable drug and strategy for subsequent anaesthetic procedures. This review provides details on the IgE endotype; an update on non-IgE related endotypes and the novel diagnostic tools that could characterise them. This detailed update is intended to provide explicit clinical reasoning tools to the anaesthesiologist faced with an incomplete AHR diagnostic work-up and to facilitate the decision-making process regarding anaesthetic procedures following an AHR to NMBAs.

Allergenic and Mas-Related G Protein-Coupled Receptor X2-Activating Properties of Drugs: Resolving the Two

Since the seminal description implicating occupation of the Mas-related G protein-coupled receptor X2 (MRGPRX2) in mast cell (MC) degranulation by drugs, many investigations have been undertaken into this potential new endotype of immediate drug hypersensitivity reaction. However, current evidence for this mechanism predominantly comes from (mutant) animal models or in vitro studies, and irrefutable clinical evidence in humans is still missing. Moreover, translation of these preclinical findings into clinical relevance in humans is difficult and should be critically interpreted. Starting from our clinical priorities and experience with flow-assisted functional analyses of basophils and cultured human MCs, the objectives of this rostrum are to identify some of these difficulties, emphasize the obstacles that might hamper translation from preclinical observations into the clinics, and highlight differences between IgE- and MRPGRX2-mediated reactions. Inevitably, as with any subject still beset by many questions, alternative interpretations, hypotheses, or explanations expressed here may not find universal acceptance. Nevertheless, we believe that for the time being, many questions remain unanswered. Finally, a theoretical mechanistic algorithm is proposed that might advance discrimination between MC degranulation from MRGPRX2 activation and cross-linking of membrane-bound drug-reactive IgE antibodies.

Mas-related G protein-coupled receptor MRGPRX2 in human basophils: Expression and functional studies

Background

Occupancy of MRGPRX2 heralds a new era in our understandings of immediate drug hypersensitivity reactions (IDHRs), but a constitutive expression of this receptor by basophils is debated.

Objective

To explore the expression and functionality of MRGPRX2 in and on basophils.

Methods

Basophils from patients with birch pollen allergy, IDHRs to moxifloxacin, and healthy controls were studied in different conditions, that is, in rest, after stimulation with anti-IgE, recombinant major birch pollen allergen (rBet v 1), moxifloxacin, fMLP, substance P (SP), or other potential basophil secretagogues. In a separate set of experiments, basophils were studied after purification and resuspension in different media.

Results

Resting whole blood basophils barely express MRGPRX2 on their surface and are unresponsive to SP or moxifloxacin. However, surface MRGPRX2 is quickly upregulated upon incubation with anti-IgE or fMLP. Pre-stimulation with anti-IgE can induce a synergic effect on basophil degranulation in IgE-responsive subjects after incubation with SP or moxifloxacin, provided that basophils have been obtained from patients who experienced an IDHR to moxifloxacin. Cell purification can trigger a "spontaneous" and functional upregulation of MRGPRX2 on basophils, not seen in whole blood cells, and its surface density can be influenced by distinct culture media.

Conclusion

Basophils barely express MRGPRX2 in resting conditions. However, the receptor can be quickly upregulated after stimulation with anti-IgE, fMLP, or after purification, making cells responsive to MRGPRX2 occupation. We anticipate that such "conditioned" basophils constitute a model to explore MRGPRX2 agonism or antagonism, including IDHRs originating from the occupation of this receptor.

Inhibition of MRGPRX2 but not FcεRI or MrgprB2-mediated mast cell degranulation by a small molecule inverse receptor agonist

Mas-related G protein-coupled receptor-X2 (MRGPRX2) expressed on mast cells (MCs) contributes to hypersensitivity reactions to cationic US-Food and Drug Administration (FDA) approved drugs such as the neuromuscular blocking agent, rocuronium. In addition, activation of MRGPRX2 by the neuropeptide substance P (SP) and the pro-adrenomedullin peptide (PAMP-12) is associated with a variety of cutaneous conditions such as neurogenic inflammation, pain, atopic dermatitis, urticaria, and itch. Thus, small molecules aimed at blocking MRGPRX2 constitute potential options for modulating IgE-independent MC-mediated disorders. Two inverse MRGPRX2 agonists, named C9 and C9-6, have recently been identified, which inhibit basal G protein activation and agonist-induced calcium mobilization in transfected HEK293 cells. Substance P serves as a balanced agonist for MRGPRX2 whereby it activates both G protein-mediated degranulation and β-arrestin-mediated receptor internalization. The purpose of this study was to determine if C9 blocks MRGPRX2's G protein and β-arrestin-mediated signaling and to determine its specificity. We found that C9, but not its inactive analog C7, inhibited degranulation in RBL-2H3 cells stably expressing MRGPRX2 in response to SP, PAMP-12 and rocuronium with an IC50 value of ~300 nM. C9 also inhibited degranulation as measured by cell surface expression of CD63, CD107a and β-hexosaminidase release in LAD2 cells and human skin-derived MCs in response to SP but not the anaphylatoxin, C3a or FcϵRI-aggregation. Furthermore, C9 inhibited β-arrestin recruitment and MRGPRX2 internalization in response to SP and PAMP-12. We found that a G protein-coupling defective missense MRGPRX2 variant (V282M) displays constitutive activity for β-arrestin recruitment, and that this response was significantly inhibited by C9. Rocuronium, SP and PAMP-12 caused degranulation in mouse peritoneal MCs and these responses were abolished in the absence of MrgprB2 or cells treated with pertussis toxin but C9 had no effect. These findings suggest that C9 could provide an important framework for developing novel therapeutic approaches for the treatment of IgE-independent MC-mediated drug hypersensitivity and cutaneous disorders.

Establishing diagnostic strategies for cannabis allergy

INTRODUCTION

Cannabis is the most widely consumed illicit drug in the world and carries a risk of severe IgE-mediated allergic reactions, requiring appropriate diagnostic management. Currently available diagnostics are still relatively limited and require careful interpretation of results to avoid harmful over- and underdiagnosis.

AREAS COVERED

This review focuses on the most up-to-date understandings of cannabis allergy diagnosis, starting with the main clinical features of the disease and the allergenic characteristics of Cannabis sativa, and then providing insights into in vivo, in vitro, and ex vivo diagnostic tests.

EXPERT OPINION

At present, the diagnosis of IgE-mediated cannabis allergy is based on a three-step approach that starts with accurate history taking and ends with a confirmation of sensitization to the whole extract and, finally, molecular components. Although much has been discovered since its first description in 1971, the diagnosis of cannabis allergy still has many unmet needs. The lack of commercial standardized and validated extracts and in vitro assays makes a harmonized workup of cannabis allergy difficult. Furthermore, the epidemiological characteristics, and clinical implications of sensitization to different molecular components are not yet fully known. Future research will complete the picture and likely result in an individualized and standardized approach.

Current and Future Strategies for the Diagnosis and Treatment of the Alpha-Gal Syndrome (AGS)

The α-Gal syndrome (AGS) is a pathognomonic immunoglobulin E (IgE)-mediated delayed anaphylaxis in foods containing the oligosaccharide galactose-α-1,3-galactose (α-Gal) such as mammalian meat or dairy products. Clinical presentation of AGS can also comprise immediate hypersensitivity due to anticancer therapy, gelatin-containing vaccines or mammalian serum-based antivenom. The IgE initial sensitization is caused by hard-bodied tick bites and symptomatic individuals typically develop delayed pruritus, urticaria, angioedema, anaphylaxis, malaise or gut-related symptoms. Due to inapparent presentation, delayed reactions and a wide variety of patients´ clinical history, the AGS diagnosis and treatment remain challenging. This review covers not only current diagnostic methods used for AGS such as the skin prick test (SPT), the oral food challenge (OFC), anti-α-Gal IgE levels measurement and the basophil activation test (BAT), but also potentially relevant next-generation diagnostic tools like the mast cell activation test (MAT), the histamine-release (HR) assay, omics technologies and model-based reasoning (MBR). Moreover, it focuses on the therapeutical medical and non-medical methods available and current research methods that are being applied in order to elucidate the molecular, physiological and immune mechanisms underlying this allergic disorder. Lastly, future treatment and preventive tools are also discussed, being of utmost importance for the identification of tick salivary molecules, with or without α-Gal modifications, that trigger IgE sensitivity as they could be the key for further vaccine development. Bearing in mind climate change, the tick-host paradigm will shift towards an increasing number of AGS cases in new regions worldwide, which will pose new challenges for clinicians in the future.

Mas-Related G Protein–Coupled Receptor-X2 and Its Role in Non-immunoglobulin E–Mediated Drug Hypersensitivity

A diverse group of Food and Drug Administration-approved cationic drugs including antibiotics, neuromuscular blocking drugs, opioids, antidepressants, and radiocontrast media activate mast cells and cause hypersensitivity reactions by both an immunoglobulin E IgE-dependent and independent manner. The recent discovery that these drugs activate mast cells via the G protein-coupled receptor known as Mas-related GPCR-X2 (MRGPRX2) has represented a paradigm shift of how drug hypersensitivity reactions are viewed. This article provides an overview of the current status of the role of MRGPRX2 on non-IgE-mediated drug hypersensitivity. Potential risk factors and evaluation for suspected MRGPRX2-mediated drug reactions are also discussed.

Scientific Opinion on development needs for the allergenicity and protein safety assessment of food and feed products derived from biotechnology

This Scientific Opinion addresses the formulation of specific development needs, including research requirements for allergenicity assessment and protein safety, in general, which is urgently needed in a world that demands more sustainable food systems. Current allergenicity risk assessment strategies are based on the principles and guidelines of the Codex Alimentarius for the safety assessment of foods derived from 'modern' biotechnology initially published in 2003. The core approach for the safety assessment is based on a 'weight-of-evidence' approach because no single piece of information or experimental method provides sufficient evidence to predict allergenicity. Although the Codex Alimentarius and EFSA guidance documents successfully addressed allergenicity assessments of single/stacked event GM applications, experience gained and new developments in the field call for a modernisation of some key elements of the risk assessment. These should include the consideration of clinical relevance, route of exposure and potential threshold values of food allergens, the update of in silico tools used with more targeted databases and better integration and standardisation of test materials and in vitro/in vivo protocols. Furthermore, more complex future products will likely challenge the overall practical implementation of current guidelines, which were mainly targeted to assess a few newly expressed proteins. Therefore, it is timely to review and clarify the main purpose of the allergenicity risk assessment and the vital role it plays in protecting consumers' health. A roadmap to (re)define the allergenicity safety objectives and risk assessment needs will be required to inform a series of key questions for risk assessors and risk managers such as 'what is the purpose of the allergenicity risk assessment?' or 'what level of confidence is necessary for the predictions?'.

The Asian wasp Vespa velutina nigrithorax: Entomological and allergological characteristics

The yellow-legged or Asian wasp (Vespa velutina nigrithorax) has spread rapidly across Europe since its first introduction in France, in 2004. Originally from South-East Asia, it is considered an invasive species outside its native region. Apart from the ecological and economic implications of its presence, it may cause health problems to humans due to the toxic and allergenic components of its venom. Vespa velutina nigrithorax has become the most prevalent cause of anaphylaxis due to Hymenoptera venom in some regions of Spain. Although sIgE against both antigen 5 (Vesp v 5) and A1-phospholipase (Vesp v 1) has been detected in these patients, only Vesp v 5 may be considered a dominant allergen. Interestingly, Vesp v 1 appears to be a glycosylated allergen different from A1-phospholipases from other species. Inhibition studies suggest that Vespula spp venom could behave as primary sensitizer. Besides, changes in sIgE and sIgG4 during Vespula venom immunotherapy in patients with anaphylaxis due to V. velutina support the use of Vespula venom extracts to treat these patients. The purpose of this review is to explore the biological behaviour of V. velutina and to summarize the current knowledge of the allergic reactions provoked by this wasp.