Clinical Relevance of Cross-Reactivity in Food Allergy

Utilizing proteomics to identify and optimize microalgae strains for high-quality dietary protein: a review

Algae-derived protein has immense potential to provide high-quality protein foods for the expanding human population. To meet its potential, a broad range of scientific tools are required to identify optimal algal strains from the hundreds of thousands available and identify ideal growing conditions for strains that produce high-quality protein with functional benefits. A research pipeline that includes proteomics can provide a deeper interpretation of microalgal composition and biochemistry in the pursuit of these goals. To date, proteomic investigations have largely focused on pathways that involve lipid production in selected microalgae species. Herein, we report the current state of microalgal proteome measurement and discuss promising approaches for the development of protein-containing food products derived from algae.

IgE-Mediated Legume Allergy: A Pediatric Perspective

Legumes are an inexpensive and essential protein source worldwide. The most consumed legumes include peanuts, soybeans, lentils, lupines, peas, common bean and chickpeas. In addition, the food industry is growing interested in expanding the use of legumes to partially replace or substitute cereals. Legumes were described to cause IgE-mediated allergies, and their growing use may also increase the incidence of allergy. The epidemiology of legume allergy varies by region; peanuts and soybeans are the legumes most involved in food allergies in Western countries, whereas lentils, peas, and chickpeas are reported as culprit allergens mainly in the Mediterranean area and India. This review, edited by the Italian Society of Pediatric Allergology and Immunology, summarizes the scientific literature on legume allergy in children and proposes a diagnostic workup and therapeutic approach.

Walnut Jug r 1 is Responsible for Primary Sensitization among Patients Suffering Walnut-Hazelnut 2S Albumin Cross-Reactivity

Walnut and hazelnut coallergy is a frequent manifestation in clinical practice whose molecular basis remains unclear. For this purpose, walnut-hazelnut cross-reactivity was evaluated in 20 patients allergic to one or both tree nuts and sensitized to their 2S albumins. Immunoblotting assays showed that 85% of patients recognized Jug r 1, walnut 2S albumin, which was associated with the development of severe symptoms; 50% of them corecognized hazelnut 2S albumin, Cor a 14. Both allergens were isolated using chromatographic techniques. Inhibition ELISAs revealed that Jug r 1 strongly inhibited the binding of Cor a 14-specific IgE, but Cor a 14 only partially inhibited Jug r 1-specific IgE binding. Our results showed that patients sensitized to walnut/hazelnut 2S albumins were not a homogeneous population. There were patients sensitized to specific epitopes of walnut 2S albumins and patients sensitized to cross-reactive epitopes between walnut and hazelnut, with Jug r 1 being the primary sensitizer.

From 'Farm to Fork': Exploring the Potential of Nutrient-Rich and Stress-Resilient Emergent Crops for Sustainable and Healthy Food in the Mediterranean Region in the Face of Climate Change Challenges

In the dynamic landscape of agriculture and food science, incorporating emergent crops appears as a pioneering solution for diversifying agriculture, unlocking possibilities for sustainable cultivation and nutritional bolstering food security, and creating economic prospects amid evolving environmental and market conditions with positive impacts on human health. This review explores the potential of utilizing emergent crops in Mediterranean environments under current climate scenarios, emphasizing the manifold benefits of agricultural and food system diversification and assessing the impact of environmental factors on their quality and consumer health. Through a deep exploration of the resilience, nutritional value, and health impacts of neglected and underutilized species (NUS) such as quinoa, amaranth, chia, moringa, buckwheat, millet, teff, hemp, or desert truffles, their capacity to thrive in the changing Mediterranean climate is highlighted, offering novel opportunities for agriculture and functional food development. By analysing how promoting agricultural diversification can enhance food system adaptability to evolving environmental conditions, fostering sustainability and resilience, we discuss recent findings that underscore the main benefits and limitations of these crops from agricultural, food science, and health perspectives, all crucial for responsible and sustainable adoption. Thus, by using a sustainable and holistic approach, this revision analyses how the integration of NUS crops into Mediterranean agrifood systems can enhance agriculture resilience and food quality addressing environmental, nutritional, biomedical, economic, and cultural dimensions, thereby mitigating the risks associated with monoculture practices and bolstering local economies and livelihoods under new climate scenarios.

From Palm to Plate: Unveiling the Potential of Coconut as a Plant-Based Food Alternative

This review investigates coconut as a sustainable and nutrient-rich plant-based alternative to traditional animal-based food sources. We have explored the nutritional profile, culinary versatility, particularly focusing on the use of coconut meat, milk, cream, and oil in diverse dietary contexts when consumed in balance. Comparative analysis with animal-derived products reveals the high content of medium-chain triglycerides (MCTs), essential vitamins, and minerals in coconut, contrasted with its lower protein content. Researchers have underscored the environmental sustainability of coconut, advocating for its role in eco-friendly food production chains. We have also addressed challenges like potential allergies, nutritional balance, sensory attributes, and consumer motivations for coconut-based products, in terms of understanding the market dynamics. In conclusion, this review positions coconut as a promising candidate within sustainable diet frameworks, advocating for further research to augment its nutritional value, sensory characteristics, and product stability, thereby facilitating its integration into health-conscious and eco-centric dietary practices.

Development of validated sandwich ELISA for detecting peanut allergen Ara h 3 in food

Peanut is an important food that can cause food allergies, often leading to moderate and severe allergic symptoms such as skin rashes, asthma, and even anaphylactic shock.Research indicates that Ara h 3 is one of the major peanut allergen. In order to establish a simple analytical method for detecting Ara h 3, we developed a sandwich enzyme-linked immunosorbent assay (ELISA) with antibodies that were induced from purified Ara h 3. The experimental results showed that the purified Ara h 3 had good purity, and we successfully prepared capture and detection antibodies. The method established in this study exhibited high specificity and did not cross-react with soybeans, cashew nuts, and sesame. For validation, including precision, recovery and sensitivity were in good condition. We also detected the Ara h 3 in peanut related foods. Overall, the ELISA developed in this study is a reliable method for Ara h 3 detection.

A comprehensive review on novel synthetic foods: Potential risk factors, detection strategies, and processing technologies

Nowadays, the food industry is facing challenges due to the simultaneous rise in global warming, population, and food consumption. As the integration of synthetic biology and food science, novel synthetic foods have obtained high attention to address these issues. However, these novel foods may cause potential risks related to human health. Four types of novel synthetic foods, including plant-based foods, cultured meat, fermented foods, and microalgae-based foods, were reviewed in the study. The original food sources, consumer acceptance, advantages and disadvantages of these foods were discussed. Furthermore, potential risk factors, such as nutritional, biological, and chemical risk factors, associated with these foods were described and analyzed. Additionally, the current detection methods (e.g., enzyme-linked immunosorbent assay, biosensors, chromatography, polymerase chain reaction, isothermal amplification, and microfluidic technology) and processing technologies (e.g., microwave treatment, ohmic heating, steam explosion, high hydrostatic pressure, ultrasound, cold plasma, and supercritical carbon dioxide) were reviewed and discussed critically. Nonetheless, it is crucial to continue innovating and developing new detection and processing technologies to effectively evaluate these novel synthetic foods and ensure their safety. Finally, approaches to enhance the quality of these foods were briefly presented. It will provide insights into the development and management of novel synthetic foods for food industry.

Comparative Seed Proteome Profile Reveals No Alternation of Major Allergens in High-Yielding Mung Bean Cultivars

Mung bean contains up to 32.6% protein and is one of the great sources of plant-based protein. Because many allergens also function as defense-related proteins, it is important to determine their abundance levels in the high-yielding, disease-resistant cultivars. In this study, for the first time, we compared the seed proteome of high-yielding mung bean cultivars developed by a conventional breeding approach. Using a label-free quantitative proteomic platform, we successfully identified and quantified a total of 1373 proteins. Comparative analysis between the high-yielding disease-resistant cultivar (MC5) and the other three cultivars showed that a total of 69 common proteins were significantly altered in their abundances across all cultivars. Bioinformatic analysis of these altered proteins demonstrated that PDF1 (a defensin-like protein) exhibited high sequence similarity and epitope matching with the established peanut allergens, indicating a potential mung bean allergen that showed a cultivar-specific response. Conversely, known mung bean allergen proteins such as PR-2/PR-10 (Vig r 1), Vig r 2, Vig r 4, LTP1, β-conglycinin, and glycinin G4 showed no alternation in the MC5 compared to other cultivars. Taken together, our findings suggest that the known allergen profiles may not be impacted by the conventional plant breeding method to develop improved mung bean cultivars.

Relationship between perioperative anaphylaxis and history of allergies or allergic diseases: A systematic review and meta-analysis with meta-regression

STUDY OBJECTIVE

We conducted this meta-analysis to summarize the available evidence and evaluate the relationship between a history of allergies/allergic diseases and perioperative anaphylaxis to offer preventive decision support.

DESIGN

Systematic review and meta-analysis of observational studies.

SETTING

We searched the MEDLINE (OVID), EMBASE, and the Cochrane Central Register of Controlled Trials databases for observational studies. Two investigators independently performed the search, screened the articles, and collected the study details.

MEASUREMENTS

Several databases were systematically searched to evaluate the relationship between a history of allergies/allergic diseases and perioperative anaphylaxis using subgroup analysis, sensitivity analysis and meta-regression.

MAIN RESULTS

A total of 19 studies involving 672 anaphylaxis episodes, 5608 immune-mediated reactions, and 1126 severe episodes met the eligibility criteria and were included in this meta-analysis. Drug allergies, food allergies, a history of allergies, and atopy increased the incidence of perioperative anaphylaxis (Drug allergies, odds ratio [OR] 3.54, 95% confidence interval [CI] 1.07-11.69; Food allergies, OR 2.29, 95% CI 1.23-4.26; A history of allergies, OR 4.86, 95% CI 3.65-6.49; Atopy, OR 3.58, 95% CI 1.47-8.71), but not the presence of immune-mediated reactions and the severity of perioperative anaphylaxis.

CONCLUSIONS

Patients with previous drug allergies, food allergies, a history of allergies, or atopy are more likely to develop anaphylaxis during the perioperative period. Additional studies should be carried out to determine whether a history of allergies/allergic diseases is a major factor for perioperative anaphylaxis when confounders are controlled.

Allergenic Shrimp Tropomyosin Distinguishes from a Non-Allergenic Chicken Homolog by Pronounced Intestinal Barrier Disruption and Downstream Th2 Responses in Epithelial and Dendritic Cell (Co)Culture

BACKGROUND

Tropomyosins (TM) from vertebrates are generally non-allergenic, while invertebrate homologs are potent pan-allergens. This study aims to compare the risk of sensitization between chicken TM and shrimp TM through affecting the intestinal epithelial barrier integrity and type 2 mucosal immune activation.

METHODS

Epithelial activation and/or barrier effects upon exposure to 2-50 μg/mL chicken TM, shrimp TM or ovalbumin (OVA) as a control allergen, were studied using Caco-2, HT-29MTX, or HT-29 intestinal epithelial cells. Monocyte-derived dendritic cells (moDC), cocultured with HT-29 cells or moDC alone, were exposed to 50 μg/mL chicken TM or shrimp TM. Primed moDC were cocultured with naïve Th cells. Intestinal barrier integrity (TEER), gene expression, cytokine secretion and immune cell phenotypes were determined in these human in vitro models.

RESULTS

Shrimp TM, but not chicken TM or OVA exposure, profoundly disrupted intestinal barrier integrity and increased alarmin genes expression in Caco-2 cells. Proinflammatory cytokine secretion in HT-29 cells was only enhanced upon shrimp TM or OVA, but not chicken TM, exposure. Shrimp TM enhanced the maturation of moDC and chemokine secretion in the presence or absence of HT-29 cells, while only in the absence of epithelial cells chicken TM activated moDC. Direct exposure of moDC to shrimp TM increased IL13 and TNFα secretion by Th cells cocultured with these primed moDC, while shrimp TM exposure via HT-29 cells cocultured with moDC sequentially increased IL13 expression and IL4 secretion in Th cells.

CONCLUSIONS

Shrimp TM, but not chicken TM, disrupted the epithelial barrier while triggering type 2 mucosal immune activation, both of which are key events in allergic sensitization.

Comprehensive Diagnosis, Management, and Treatment of Sesame Allergy

Sesame allergy prevalence varies regionally and by age, in the range of 0.1% to 0.9%. Reactions can be severe and potentially fatal. Resolution rates are in the range of 20% to 50%. The diagnosis requires a careful history and the use of tests, such as skin prick tests and serum sesame-specific IgE. The availability of serum IgE testing for the sesame protein Ses i 1 has improved diagnostic accuracy. The emerging potential for sesame basophil activation tests and additional new tests will likely improve diagnosis in coming years, further reducing the need for diagnostic oral food challenges. Although sesame proteins share homology with those in many foods, clinically relevant cross-reactivity appears uncommon. Nevertheless, sesame is a prominent allergen for those with multiple food allergies. Management may include strict avoidance, but sesame products vary dramatically in protein content. Many people with sesame allergy tolerate forms that are low in protein, such as scattered seeds, rather than sesame paste that is protein-dense. Thus, options in the approach to avoidance are possible. Studies suggest that sesame oral immunotherapy may be safe and effective, and this and additional treatment options are emerging. Here, we review the current comprehensive diagnosis, management, and treatment for sesame allergy.

Diagnosis and Management of Pollen Food Allergy Syndrome to Nuts

Oral allergy syndrome or pollen food allergy syndrome (PFAS) represents a common clinical conundrum when the reported trigger food is a tree nut (usually almond or hazelnut) or peanut. The PFAS may give rise to uncertainty about the potential severity of the future reactions, indications for prescribing epinephrine, and the extent of the necessary dietary avoidance. As a food allergy, secondary to cross-reactivity with airborne pollen, PFAS usually manifests toward the end of the first decade of life as contact urticaria of the oropharyngeal mucous membranes. Molecular allergology facilitates diagnosis and risk stratification by establishing the profile of sensitization. Exclusive sensitization to pathogenesis-related proteins family 10 (PR10) and profilins indicates that signs and symptoms are due to PFAS, whereas sensitization to seed storage proteins with or without sensitization to PR10 and profilins may indicate a more severe primary nut allergy phenotype. Management relies on avoidance of the specific nut trigger, advice on the likelihood of more severe local or systemic symptoms, and treatment of reactions according to the severity. Future studies are needed to better delineate the risk of systemic reactions in individuals with nut PFAS and to establish the role of food or pollen allergen immunotherapy for the prevention or moderation of this condition.

Oral immunotherapy with sunflower seed butter and a review of seed allergy

Food allergy to seeds is increasingly more common, with sesame being the most prevalent. Allergy to other seeds, including sunflower, pumpkin, poppy, mustard, and flaxseed, have been reported. Diagnosing a seed allergy is challenging, with many seeds being hidden additives in processed foods and cross-reactive testing. Food labels in the United States are now required to indicate the presence of sesame but other seeds are not required. Oral immunotherapy (OIT) protocols for peanut, milk, and egg are clinically being extrapolated to other foods, including sesame and sunflower seed. This article highlights a case of a patient in whom sunflower seed OIT was administered in a clinical setting.

Adverse Food Reactions in Inflammatory Bowel Disease: State of the Art and Future Perspectives

Limited knowledge is available about the relationship between food allergies or intolerances and inflammatory bowel disease (IBD). Clinicians frequently encounter patients who report food allergies or intolerances, and gastroenterologists struggle distinguishing between patients with organic disorders and those with functional disorders, which the patients themselves may associate with specific dietary components. This task becomes even more arduous when managing patients with significant underlying organic conditions, like IBD. The aim of this review is to summarize and emphasize any actual associations between food allergies and intolerances and inflammatory diseases, such as ulcerative colitis and Crohn's disease. Through a narrative disceptation of the current literature, we highlight the increased prevalence of various food intolerances, including lactose, fructose, histamine, nickel, and non-celiac gluten sensitivity, in individuals with IBD. Additionally, we explore the association between increased epithelial barrier permeability in IBD and the development of food sensitization. By doing so, we aim to enhance clinicians' awareness of the nutritional management of patients with IBD when facing complaints or evidence of food allergies or intolerances.

Latex Allergy - From Discovery to Component-resolved Diagnosis

Latex allergy is a hypersensitivity response to natural rubber latex (NRL) proteins or rubber chemicals used in the manufacture of latex products. An accurate diagnosis is the first step in the effective management of individuals with latex allergy, especially in high-risk groups, such as healthcare workers and those affected by spina bifida. Diagnosis is based on the clinical history and an accurate allergological evaluation. In the case of type I IgE-mediated hypersensitivity reactions, which can manifest urticaria, angioedema, rhinoconjunctivitis, asthma and anaphylaxis after latex exposure, skin prick tests or latex-specific IgE (sIgE) antibody detection using serological assays can be performed to confirm sensitization. Instead, in the case of contact dermatitis, a patch test can be applied to confirm the presence of a type IV T cell-mediated hypersensitivity reaction to rubber accelerators or additives. Basophils activation tests or challenge tests may be performed if there's an incongruity between the clinical history and the results of in vivo and in vitro tests. The aim of this review is to analyze the current state of the art of diagnostic techniques for latex allergy and algorithms employed in clinical practice and possible future developments in this field.

Preparation of Blinded Food Matrixes for Clinical Oral Challenges

Clinically, oral food challenges have value in the diagnosis and management of food allergy. Oral food challenges are used not only for diagnostic confirmation that ingestion of a specific food elicits an adverse reaction, but also for determining individual threshold doses, tracking the progress toward desensitization during immunotherapy, determining the effect of processing on the allergenicity of a specific food, assessing the allergenicity of an ingredient derived from an allergenic source, and tracking the progress toward development of age-related tolerance to a specific food. To eliminate bias in oral challenges, the food under investigation is masked in a matrix so that it is not sensorially detectable by the patient or the clinical observer. The preparation of oral challenge foods requires care in the selection of the allergenic components, the selection of the components of the matrix, the masking of the allergenic component, and the homogeneity of the allergen in the overall matrix.

Getting the BS out of Irritable Bowel Syndrome with Diarrhea (IBS-D): Let's Make a Diagnosis

PURPOSE OF REVIEW

Irritable bowel syndrome with diarrhea (IBS-D) is diagnosed when chronic symptoms of abdominal pain accompany loose stools, and alarm features, such as fever, anemia, rectal bleeding, and weight loss are absent. This combination of symptoms makes structural disorders, such as inflammatory bowel disease or cancer, unlikely, but does not exclude other conditions that cause these symptoms. The question is whether making a "positive diagnosis" of IBS-D based on symptoms alone and instituting therapy based on that diagnosis still makes sense.

RECENT FINDINGS

Clinical observations suggest that at least two-thirds of cases of IBS-D can be explained by three mechanisms: a) food intolerances (~ 30-40%), b) bile acid diarrhea (~ 20-30%), and c) disturbed microbial flora (~ 15-20%). Other conditions that are less frequent but can cause IBS symptoms or be confused with IBS include: celiac disease, microscopic colitis, mastocytosis/mast cell activation, and drug side-effects. Many cases of IBS-D have a discoverable, underlying cause that can direct therapy more efficiently.

[Oral allergy syndrome (OAS)]

The pollen-food allergy syndrome, also known as oral allergy syndrome, is characterized by local reactions in the mouth and throat after consuming certain raw plant foods in individuals sensitized to pollen from grass, weeds, and trees. Birch-apple is the prototype of this syndrome, with apple, pear, and plum being the most commonly associated foods. Symptoms are usually limited to the oral cavity but can include systemic reactions, including anaphylaxis. Sensitization to pollen allergens, such as lipid transfer proteins, profilin, and PR-10 proteins, triggers this syndrome. Its prevalence varies by geographic region and the predominant pollen type, affecting between 30% and 60% of food allergies. Diagnosis involves a clinical history, skin tests, and, in ambiguous cases, double-blind, placebo-controlled oral food challenges. Treatment primarily involves avoiding trigger foods.

[Phenotypes and endotypes of food allergy]

Food allergy is a common event, especially in the pediatric population, affecting between 3-6% of children. There are various challenges in the care of patients with food allergy, but certainly the diversity of symptoms and the outcome of the disease are important aspects in the treatment of patients, in the development of care guidelines and in the knowledge of the Natural history of disease. The classification into phenotypes allows a better understanding of the evolution of food allergy. The endotype is a subtype of a phenotype defined by its pathophysiological characteristic. Genetic, epigenetic, and environmental characteristics interfere with the construction of the phenotype and its possible endotypes. Understanding the phenotypes and endotypes of food allergies brings with it two fundamental aspects: 1) the need to understand that the analysis of phenotypes and endotypes in food allergies will allow establishing prognoses and helping in intervention with specific therapies, and 2) the importance of understanding The characterization of local endotypes and phenotypes, and the dietary diversity of the different countries that make up Latin America brings with it a varied menu of foods that may pose a risk of allergy that needs to be studied.

[Physiopathology of food allergies]

Food allergy is an adverse reaction to certain foods that have demonstrated "immunological mechanisms"; therefore, this term covers both food allergies mediated or not by immunoglobulin E (IgE). The common pathophysiological mechanism among forms of allergy to foods mediated or not by IgE is found in the failure of clinical and immunological tolerance towards that food. The induction and maintenance of immunological tolerance depends on the active generation of regulatory T cells specific for food antigens. This process is influenced by genetic factors (FOXP3 genes) and epigenetic factors conditioned by the environment (diet, microbiota, and their products). Since the intestinal microbiome can normally promote oral tolerance, current evidence suggests that perturbations of the microbiome may correlate, or even predispose, with food allergy. Understanding the pathogenic mechanism underlying IgE-mediated food allergies allows the implementation of measures aimed at restoring clinical and immunological tolerance. Knowledge of the mechanisms of food allergy will improve the outlook for patients with more severe immediate food allergies and anaphylaxis, as well as those who have comorbidities (atopic dermatitis, eosinophilic esophagitis and EGEIDs).

Molecular characterization and allergenicity assessment of different samples of Mung Bean

Legumes represent a promising nutritional alternative source of proteins to meat and dairy products. Additionally, Novel Foods (Regulation EU 2015/2283) can help meet the rising protein demand. However, despite their benefits, emerging allergenicity risks must be considered. The aim of this work is the molecular characterization of the Novel Food Mung bean protein isolate for allergenicity prediction with High Resolution Mass Spectrometry analysis. The assessment of the allergenicity was evaluated in silico by comparing protein sequences of the Novel Food with other known legume allergens, using bioinformatic databases. The results highlighted similarity higher than 60 % of the protein structure of Mung bean with two known allergens of soybean and pea. Furthermore, enzymatic hydrolysis effects on allergenic potential was evaluated by immunoblotting analysis using sera of patients allergic to legumes. The protein hydrolysates obtained showed a high nutritional quality and a reduced allergenic potential, making them suitable for hypoallergenic food formulations.

Benefits of Soybean in the Era of Precision Medicine: A Review of Clinical Evidence

Soybean (Glycine max) is an important ingredient of cuisines worldwide. While there is a wealth of evidence that soybean could be a good source of macronutrients and phytochemicals with health-promoting effects, concerns regarding adverse effects have been raised. In this work, we reviewed the current clinical evidence focusing on the benefits and risks of soybean ingredients. In breast, prostate, colorectal, ovarian, and lung cancer, epidemiological studies showed an inverse association between soybean food intake and cancer risks. Soybean intake was inversely correlated with risks of type 2 diabetes mellitus (T2DM), and soy isoflavones ameliorated osteoporosis and hot flashes. Notably, soybean was one of the dietary protein sources that may reduce the risk of breast cancer and T2DM. However, soybean had adverse effects on certain types of drug treatment and caused allergies. In sum, this work provides useful considerations for planning clinical soybean research and selecting dietary protein sources for human health.

Food allergy - New risks through vegan diet? Overview of new allergen sources and current data on the potential risk of anaphylaxis

A vegan diet is increasingly en vogue, i.e., a diet based on plants, in which animal products are completely avoided, often for health and environmental reasons. The menu is supplemented with pulses (e.g., soy, lentils, peas), nuts (e.g., cashew, macadamia, almond, pecan, para, walnut) and seeds (e.g., chia, flaxseed) or pseudo-grains (quinoa, buckwheat). Indeed, the product range is expanding to include vegan foods such as milk alternatives (e.g., oat, almond, soy drinks) and cheese or meat substitutes (e.g., soy-based). Food allergies are also on the rise, with an increasing prevalence worldwide. It is worthy of note that the main allergens of anaphylactic reactions to food in adults are predominantly of plant origin, mainly pulses and nuts - the very foods that form the main source of protein in the vegan diet. In this context, allergies to storage proteins (e.g., Gly m 5 and Gly m 6 from soya beans) can lead to severe anaphylactic reactions, while highly processed substitute products containing plant protein isolates (e.g., pea flour) in concentrated form continue to be of particular concern and may therefore be allergologically problematic. In this article, we aim to provide an overview of allergens and emerging allergen sources in vegan foods and highlight the anaphylaxis risk of the vegan diet.

Nahrungsmittelallergie - Neue Risiken durch vegane Ernährung? Überblick zu neuen Allergenquellen und aktuelle Daten zum Anaphylaxierisiko: Food allergy - New risks through vegan diet? Overview of new allergen sources and current data on the potential risk of anaphylaxis

Zunehmend mehr Menschen ernähren sich aus gesundheitlichen und Umweltaspekten ausschließlich von pflanzlichen Nahrungsmitteln (vegan). Dabei werden vielfach Hülsenfrüchte (wie Soja, Linsen, Erbsen), Schalenfrüchte (Cashew, Macadamia, Mandel, Pekan‐, Para‐ und Walnuss), Samen und Saaten (wie Chia, Leinsamen) oder (Pseudo‐)Getreide (wie Quinoa, Buchweizen) verzehrt. Vegane Milchalternativen sind Hafer‐, Mandel‐ und Sojadrinks, auch Käse‐ sowie Fleischersatzprodukte basieren oft auf einer Sojagrundlage. Gleichzeitig nimmt die Prävalenz von Nahrungsmittelallergien weltweit zu. Pflanzenallergene aus Hülsen‐ und Schalenfrüchten, die in der veganen Ernährung die Hauptproteinquelle ausmachen, zählen zu den häufigsten Auslösern von Nahrungsmittelallergien bei Erwachsenen. Dabei kommt es bei Allergien auf Speicherproteine (wie Gly m 5 und Gly m 6 aus der Sojabohne) zu teils schweren anaphylaktischen Reaktionen. Besonderes Augenmerk liegt weiter auf hochverarbeiteten Ersatzprodukten, die Pflanzenproteinisolate (zum Beispiel Erbsenmehl) in konzentrierter Form enthalten und damit allergologisch problematisch werden können. In diesem Artikel geben wir einen Überblick über wichtige Allergene und neue Allergenquellen in ausgesuchten veganen Nahrungsmitteln und betrachten die vegane Ernährung unter allergologischen Aspekten.

IgE Mediated Shellfish Allergy in Children-A Review

Shellfish is a leading cause of food allergy and anaphylaxis worldwide. Recent advances in molecular characterization have led to a better understanding of the allergen profile. High sequence homology between shellfish species and between shellfish and house dust mites leads to a high serological cross-reactivity, which does not accurately correlate with clinical cross-reactions. Clinical manifestations are immediate and the predominance of perioral symptoms is a typical feature of shellfish allergy. Diagnosis, as for other food allergies, is based on SPTs and specific IgE, while the gold standard is DBPCFC. Cross-reactivity between shellfish is common and therefore, it is mandatory to avoid all shellfish. New immunotherapeutic strategies based on hypoallergens and other innovative approaches represent the new frontiers for desensitization.

Not Just a Banana: The Extent of Fruit Cross-Reactivity and Reaction Severity in Adults with Banana Allergy

This cross-sectional study aimed to investigate the prevalence and clinical characteristics of cross-reactivity and co-allergy to other plant foods among adult patients with IgE-mediated banana allergy in Thailand. A structured questionnaire was used to assess clinical reactivity, and cross-reactivity diagnoses were based on reactions occurring within 2 years of banana allergy onset, within 3 h of intake, and confirmed by allergists. Among the 133 participants, the most commonly associated plant foods with clinical reactions were kiwi (83.5%), avocado (71.1%), persimmon (58.8%), grapes (44.0%), and durian (43.6%). Notably, 26.5% of the reported reactions to other plant foods were classified as severe. These findings highlight the common occurrence of cross-reactivity/co-allergy to other plant foods in banana-allergic patients, with a significant proportion experiencing severe reactions. Travelers to tropical regions should be aware of this risk and advised to avoid specific banana cultivars and plant foods with reported high cross-reactivity. The inclusion of self-injectable epinephrine in the management plan for patients with primary banana allergy should be considered due to the substantial proportion of reported severe reactions and the wide range of clinical cross-reactivity and co-allergy observed.

Food Allergies and Parasites in Children

The dynamically growing incidence of food allergies forces the scientific community to develop new methods for their diagnosis, differentiation, and effective treatment. Parasitoses appear much less frequently in the scientific literature, as well as among the presumed causes of numerous conditions. The similarity of inflammatory mechanisms in allergies and parasitosis necessitates a revision of current diagnostic standards. A lack of specificity and the coincidence of symptoms at an early stage of disease can lead to misdiagnosis. In this paper, we attempted to perform a comparative analysis of the similarities and differences in symptoms for these two types of diseases. We described the molecular mechanisms and metabolic pathways of food allergy and parasitosis. We presented the available research methods and directions of ongoing studies aimed at implementing precise medical techniques for differential diagnosis. We discussed the allergenic properties of certain parasite proteins, using the example of myofibrillar tropomyosins from the nematode Anisakis simplex. The literature in the fields of allergology and parasitology leads to the conclusion that it is reasonable to run parallel allergological and parasitological diagnostics in patients with non-specific symptoms. This approach will facilitate accurate and early diagnosis and implementation of effective therapy.

Food Allergens in Ultra-Processed Foods According to the NOVA Classification System: A Greek Branded Food Level Analysis

Ultra-processed foods' (UPFs') consumption has been positively linked to the presence of allergic symptoms, but it is yet unknown whether this is linked to their nutritional composition or allergen load. This study used the ingredient lists available in the Greek Branded Food Composition Database, HelTH, to classify foods (n = 4587) into four grades of food processing (NOVA1-4) according to the NOVA System. Associations between NOVA grades and the presence of allergens (as an ingredient or trace) were studied. Overall, UPFs (NOVA4) were more likely to contain allergens than unprocessed foods, NOVA1 (76.1% vs. 58.0%). However, nested analyses among similar foods showed that in >90% of cases, processing degree was not linked to allergens' presence. Recipe/matrix complexity was more strongly linked to allergens' presence with NOVA4 foods declaring 1.3 allergenic ingredients vs. 0.4 allergenic ingredients in NOVA1 foods (p < 0.01). Exposure to trace allergens was more common for NOVA4 than NOVA1 foods (45.4% vs. 28.7%), but the extent of contamination was similar (2.3 vs. 2.8 trace allergens). Overall, UPFs are more complex mixtures with higher numbers of allergens per food and are more prone to cross-contamination. However, indicating a food's degree of processing is not sufficient to help identify allergen-free choices within the same subcategory.

IgE-Mediated Shellfish Allergy in Children

Shellfish, including various species of mollusks (e.g., mussels, clams, and oysters) and crustaceans (e.g., shrimp, prawn, lobster, and crab), have been a keystone of healthy dietary recommendations due to their valuable protein content. In parallel with their consumption, allergic reactions related to shellfish may be increasing. Adverse reactions to shellfish are classified into different groups: (1) Immunological reactions, including IgE and non-IgE allergic reactions; (2) non-immunological reactions, including toxic reactions and food intolerance. The IgE-mediated reactions occur within about two hours after ingestion of the shellfish and range from urticaria, angioedema, nausea, and vomiting to respiratory signs and symptoms such as bronchospasm, laryngeal oedema, and anaphylaxis. The most common allergenic proteins involved in IgE-mediated allergic reactions to shellfish include tropomyosin, arginine kinase, myosin light chain, sarcoplasmic calcium-binding protein, troponin c, and triosephosphate isomerase. Over the past decades, the knowledge gained on the identification of the molecular features of different shellfish allergens improved the diagnosis and the potential design of allergen immunotherapy for shellfish allergy. Unfortunately, immunotherapeutic studies and some diagnostic tools are still restricted in a research context and need to be validated before being implemented into clinical practice. However, they seem promising for improving management strategies for shellfish allergy. In this review, epidemiology, pathogenesis, clinical features, diagnosis, and management of shellfish allergies in children are presented. The cross-reactivity among different forms of shellfish and immunotherapeutic approaches, including unmodified allergens, hypoallergens, peptide-based, and DNA-based vaccines, are also addressed.

Research progress on the allergic mechanism, molecular properties, and immune cross-reactivity of the egg allergen Gal d 5

Eggs and their products are commonly consumed in food products worldwide, and in addition to dietary consumption, egg components are widely used in the food industry for their antimicrobial, cooking, and other functional properties. Globally, eggs are the second most common allergenic food after milk. However, current research on egg allergy primarily focuses on egg white allergens, while research on egg yolk allergens is not comprehensive enough. Therefore, summarizing and analyzing the important allergen α-livetin in egg yolk is significant in elucidating the mechanism of egg allergy and exploring effective desensitization methods. This paper discusses the incidence, underlying mechanism, and clinical symptoms of egg allergy. This article provides a comprehensive summary and analysis of the current research status concerning the molecular structural properties, epitopes, and immune cross-reactivity of the egg yolk allergen, Gal d 5. Additionally, it examines the effects of various processing methods on egg allergens. The article also offers suggestions and outlines potential future research directions and ideas in this field.

Pollen Sensitization Can Increase the Allergic Reaction to Non-Cross-Reactive Allergens in a Soy-Allergic Patient

During and after the pollen season, an increase in food-triggered allergic symptoms has been observed in pollen-food syndrome patients, possibly due to seasonal boosting of pollen-IgE levels. It has been suggested that consumption of birch-pollen-related foods plays a role in seasonal allergenic inflammation. However, whether this increased pollen sensitization during the pollen season can also affect the allergenicity of allergens that are non-cross-reactive with birch pollen remains in question. This study presents the case of a patient with soy allergy and pollinosis, who experiences worsening of gastrointestinal (GI) symptoms during the birch pollen season even though the eliciting food factor does not cross-react with birch pollen allergens and their homologs (e.g., Bet v 1 and Gly m 4). The results showed a notable increase in sIgE for Gly m 4 (3.3 fold) and Bet v 1 (2.6 fold) during the birch pollen season compared to outside the birch pollen season, while Gly m 5 and Gly m 6 showed only a slight increase (1.5 fold). The basophil activation test (BAT) showed that in this patient Gly m 5 and Gly m 6 are clinically relevant soy allergens, which correlates with the reported clinical symptoms to processed soy. Moreover, the BAT against raw soy shows an increase in basophil activation during the birch pollen season and a negative basophil activation result outside the birch pollen season. Thus, the worsening of GI symptoms could possibly be due to an increase in IgE receptors, an over-reactive immune system, and/or significant intestinal allergic inflammation. This case highlights the importance of including allergens that do not cross-react with birch pollen and using a functional assay such as the BAT to evaluate clinical relevance when assessing birch pollen seasonal influence on soy allergenicity.

Immunodetection of finfish residues on food contact surfaces

Finfish is one of the major allergenic foods, whose declaration is required on packages. Undeclared allergenic residues are mainly derived from allergen cross-contact. Swabbing of food contact surfaces helps to detect allergen cross-contamination. This study aimed to establish a competitive enzyme-linked immunosorbent assay (cELISA) to quantify the major finfish allergen, parvalbumin, from swab samples. First, parvalbumin from four finfish species was purified. Its conformation was investigated under reducing, non-reducing and native conditions. Second, one anti-finfish parvalbumin monoclonal antibody (mAb) was characterized. This mAb had a calcium-dependent epitope which was highly conserved in finfish species. Third, one cELISA was established with a working range between 0.59 ppm and 150 ppm. It showed a good recovery of swab samples on food-grade stainless steel and plastic surfaces. Overall, this cELISA could detect a trace amount of finfish parvalbumins on cross-contact surfaces, which is suitable for allergen surveillance in the food industry.

Cross-reactive epitopes and their role in food allergy

Allergenic cross-reactivity among food allergens complicates the diagnosis and management of food allergy. This can result in many patients being sensitized (having allergen-specific IgE) to foods without exhibiting clinical reactivity. Some food groups such as shellfish, fish, tree nuts, and peanuts have very high rates of cross-reactivity. In contrast, relatively low rates are noted for grains and milk, whereas many other food families have variable rates of cross-reactivity or are not well studied. Although classical cross-reactive carbohydrate determinants are clinically not relevant, α-Gal in red meat through tick bites can lead to severe reactions. Multiple sensitizations to tree nuts complicate the diagnosis and management of patients allergic to peanut and tree nut. This review discusses cross-reactive allergens and cross-reactive carbohydrate determinants in the major food groups, and where available, describes their B-cell and T-cell epitopes. The clinical relevance of these cross-reactive B-cell and T-cell epitopes is highlighted and their possible impact on allergen-specific immunotherapy for food allergy is discussed.

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.

Development of sensitization to peanut and storage proteins and relation to markers of airway and systemic inflammation: A 24-year follow-up

BACKGROUND

Long-time data of peanut allergy over time is sparse. We aimed to study the longitudinal development of sensitization to peanut extract and storage protein allergen molecules and associations with asthma status, airway and systemic inflammation markers.

METHODS

The Swedish birth cohort BAMSE followed 4089 participants with questionnaires, clinical investigations and blood sampling between 0 and 24 years. Information on (i) background factors at 2 months, (ii) peanut allergy symptoms and IgE data (ImmunoCAP) at 4, 8, 16, and 24 years, and (iii) IgE to storage proteins, lung function data including exhaled nitric oxide (FENO) as well as systemic inflammatory markers at 24 years of age were collected.

RESULTS

The prevalence of peanut extract sensitization, defined as IgE ≥ 0.35 kU_A /L, was 5.4%, 8.0%, 7.5%, and 6.2% at 4, 8, 16, and 24 years of age, respectively. Between 8 and 24 years of age, (33/1565) participants developed IgE-ab to peanut extract (median 1,4, range 0.7-2.6 kU_A /L), and among those 85% were also sensitized to birch. Only six individuals developed sensitization to Ara h 2 (≥0.1 kU_A /L) between 8 and 24 years of age, of whom three had an IgE-ab level between 0.1-0.12 kU_A /L. Storage protein sensitization was associated with elevated FENO, blood eosinophils and type 2 inflammation-related systemic proteins.

CONCLUSION

Sensitization to peanut extract after 4 years of age is mainly induced by birch cross-sensitization and IgE to Ara h 2 rarely emerges after eight years of age. Storage protein sensitization is associated with respiratory and systemic inflammation.

High prevalence of lupin allergy among patients with peanut allergy: Identification of γ-conglutin as major allergen

BACKGROUND

Lupin is a protein-rich legume with a growing presence in the food market worldwide. With increased consumption, lupin allergy (LA) reports are also rising. Uncertainties exist on the cross-reactivity between peanut and lupin, the allergenic potential of different lupin species, and sensitization patterns among different populations.

OBJECTIVE

To evaluate the molecular basis of LA and to determine lupin allergens from 3 different species that may be involved in peanut allergy (PA) cross-reactivity.

METHODS

A total of 43 subjects with PA, those with LA, or controls without food allergy were evaluated with skin prick tests (SPTs) and specific IgEs (sIgEs). Lupin-sensitized subjects were offered a lupin oral food challenge (OFC). Immunoblots and enzyme-linked immunosorbent assays were performed on sera from lupin-sensitized subjects.

RESULTS

In this study, 44% of the PA subjects were confirmed to have LA by OFC. Anaphylaxis was the most frequent manifestation after lupin consumption, with a minimal eliciting dosage of 1 g lupin flour. There was no difference in lupin sIgE or SPT wheal size between lupin-sensitized and confirmed LA subjects or in the severity of symptoms among confirmed LA subjects. Sera from lupin-sensitized subjects uniformly reacted to all 3 different lupin species. Immunoblotting and enzyme-linked immunosorbent assays revealed immunoglobulin E binding to α- and γ-conglutin in all analyzed sera, whereas α- and β-conglutin recognition was variable.

CONCLUSION

Our findings reveal a high prevalence of LA among PA subjects, emphasizing lupin must be labeled as an allergen in foods. Owing to high variability in lupin-sIgE and lupin-SPT results, LA diagnosis may require OFC. In our population, γ-conglutin is the major allergen of lupin.

Parvalbumin: A Major Fish Allergen and a Forensically Relevant Marker

Parvalbumins (PVALBs) are low molecular weight calcium-binding proteins. In addition to their role in many biological processes, PVALBs play an important role in regulating Ca2+ switching in muscles with fast-twitch fibres in addition to their role in many biological processes. The PVALB gene family is divided into two gene types, alpha (α) and beta (β), with the β gene further divided into two gene types, beta1 (β1) and beta2 (β2), carrying traces of whole genome duplication. A large variety of commonly consumed fish species contain PVALB proteins which are known to cause fish allergies. More than 95% of all fish-induced food allergies are caused by PVALB proteins. The authentication of fish species has become increasingly important as the seafood industry continues to grow and the growth brings with it many cases of food fraud. Since the PVALB gene plays an important role in the initiation of allergic reactions, it has been used for decades to develop alternate assays for fish identification. A brief review of the significance of the fish PVALB genes is presented in this article, which covers evolutionary diversity, allergic properties, and potential use as a forensic marker.

Management of Adult Patients with Gastrointestinal Symptoms from Food Hypersensitivity-Narrative Review

The incidence of food hypersensitivity has increased dramatically over the years not only among children but also in adults. Adult patients are usually less suspected of food hypersensitivity symptoms since food allergies are more typical for small children, with a tendency to outgrow the condition. The aim of this article is to increase awareness of hypersensitivity to food symptoms and their diagnosis and treatment possibilities among gastroenterologists and other health care professionals dealing with this type of patient. Symptoms of many gastrointestinal disorders, especially functional, may be driven by different types of mechanisms, and food intolerance or allergy should be considered as a potential cause. This article presents the current understanding of the epidemiology, diagnosis and treatment of immune- and non-immune-mediated food-induced diseases. Diagnosis of food hypersensitivity is based mainly on medical history, different types of sensitivity tests, e.g., hydrogen breath test, specific IgE (sIgE) serum concentration, tissue eosinophil count, skin tests and oral food challenges considered as a "gold standard" for food allergy. Elimination diet and pharmacologic treatment for allergy symptoms are first-line therapies. Eosinophilic gastrointestinal diseases are often caused by non-IgE-mediated food allergies, require endoscopic biopsy samples to confirm diagnosis and proper elimination diet often combined with steroids or proton pump inhibitor agents for treatment. Mast cell activation syndrome (MCAS) derives from pathologic reaction of mast cells with increased tryptase serum level as a marker. Symptoms may occur in the digestive, respiratory, skin, neurologic and cardiovascular system. Treatment is based on histamine type 1, type 2 (H1, H2) receptor antagonists and other mast cell stabilizing agents. Carbohydrate intolerances are the most common type of food hypersensitivity in adult patients, and an elimination diet is effective for reducing symptoms. Food additives hypersensitivity remains difficult to diagnose, but use of a diet low in chemical substances alleviates symptoms and helps to diagnose the triggering factors.

Contact Urticaria Syndrome: a Comprehensive Review

Purpose of Review

Contact urticaria syndrome includes contact urticaria and protein contact dermatitis. Underreport, underdiagnosis, or misdiagnosis of entities within the contact urticaria syndrome is believed to be common, especially in the occupational setting. This review provides a structured overview of the entities comprised in this syndrome as well as the diagnostic work-up and management strategies.

Recent Findings

Contact urticaria syndrome has been increasingly described due to personal protective equipment and hand sanitizers in the context of the COVID-19 pandemic. The use of legal cannabis products has led to a rise in occupational cases of contact urticaria to cannabis. A declining trend in the evolution of contact urticaria has been described for natural rubber latex allergy due to the use of synthetic gloves. Prick test has been proposed as a screening method, particularly if multiple products are to be tested, instead of the classical sequential scheme.

Summary

Physicians should be aware of the growing number of culprit agents leading to contact urticaria syndrome. Clinical presentation may be challenging since it includes immediate urticaria and/or eczema and even more generalized reactions. Diagnosis requires a high degree of suspicion, detailed occupational history, and complementary tests, including skin testing. The best treatment is to avoid contact with the culprit agent and to implement preventive measures.

Peanut, soy, and emerging legume allergy in Canada

Background

Individuals with 1 legume allergy may be cosensitized to other legumes and thus may potentially have other legume allergies as well. Although the use of emerging legumes (eg, pea, lentils, chickpeas) in commercial food production is increasingly common, the literature has largely focused on peanut and soy, both of which are priority allergens in Canada.

Objective

We aimed to describe the distribution of priority and emerging legume allergies in Canada, with consideration for patient age.

Methods

Cross-sectional survey data collected between 2019 and 2021 from families who follow food allergy-related social media platforms were queried for demographics, as well as for food allergy (including by type and number of foods and by age [0-5 vs ≥6 years]). Data were described and then analyzed by using logistic regression and adjusted for sex, age at diagnosis, and number of food allergies.

Results

Of the 115 participating children, the majority (64.6%) were boys. Nearly all of the children (109 of 115 [94.8%]) had peanut allergy, whereas soy and emerging legume allergies were reported by 15.7% and 13.0% of the children, respectively. Of these 115 children, 85 had mono-peanut allergy, 6 had mono-soy allergy, none had emerging legume allergy in the absence of peanut or soy, 12 had peanut and emerging legume allergy, 9 had peanut and soy allergy, and 3 had peanut, soy, and emerging legume allergy. Compared with children aged 0 to 5 years, children aged 6 years or older were significantly less likely to have peanut plus soy or emerging legume allergy (odds ratio = 0.22 [95% CI = 0.05-0.94]; P = .04).

Conclusion

Of the children with peanut allergy, a considerable number also had peanut allergy and soy allergy and/or another legume allergy. Younger children have higher odds of multiple legume allergy.

Clinical cross-reactivity of wheat and barley in children with wheat allergy

BACKGROUND

Several studies have reported in vitro cross-reactivity between wheat and barley. However, evidence regarding the clinical cross-reactivity of wheat and barley is limited. This study examined the clinical cross-reactivity of barley and wheat among children with immediate-type wheat allergies.

METHODS

We examined the threshold dose of a wheat oral food challenge for wheat-allergic children. We examined the reactivity of barley, and the oral food challenges of barley tea and barley rice were implemented as needed. We measured the specific immunoglobulin E (sIgE) levels in wheat, ω-5 gliadin, and barley.

RESULTS

We evaluated 53 children (39 [74%] boys) with a median age of 6.6 years. Among them, 39 (74%) patients had a history of anaphylaxis to wheat. The median wheat-, barley-, and ω-5 gliadin-sIgE levels were 57.3, 12.1, and 3.2 kU_A /L, respectively. Twelve patients reacted to barley tea (1.8 mg), 14 reacted to barley rice (220-440 mg), and 27 were tolerant to barley tea and barley rice. Barley-allergic patients had significantly higher wheat- and ω-5 gliadin- and barley-sIgE levels and significantly lower threshold doses of wheat than barley-tolerant patients. Omega-5 gliadin-sIgE was the most useful predictor of barley allergy among wheat-allergic patients; the ω-5 gliadin-sIgE 95% positive predictive value for barley allergy was 4.6 kU_A /L.

CONCLUSIONS

Half of wheat-allergic children reacted to barley. A lower threshold dose of wheat is related to cross-reactive barley allergies. Omega-5 gliadin-sIgE predicts cross-reactive barley allergy in children allergic to wheat. Clinical cross-reactivity to barley should be considered in the management of wheat-allergic children.

IgE Epitope Analysis for Scy p 1 and Scy p 3, the Heat-Stable Myofibrillar Allergens in Mud Crab

Tropomyosin (Scy p 1) and myosin light chain (Scy p 3) are investigated to be important heat-stable allergens in Scylla paramamosain. However, the epitopes of Scy p 1 and Scy p 3 are limited. In this study, recombinant Scy p 1 and Scy p 3 had similar IgE-binding capacity to natural proteins. Mimotopes of Scy p 1 and Scy p 3 were analyzed by bioinformatics, phage display, and one-bead-one-compound technology. Ten linear epitopes of Scy p 1 and seven linear epitopes of Scy p 3 were identified by synthetic peptides and inhibition dot blot. Meanwhile, three conformational epitopes of Scy p 1 and seven conformational epitopes of Scy p 3 were verified by site-directed mutagenesis and the serological test. Furthermore, strong IgE-binding epitopes of Scy p 1 and Scy p 3 were conserved in multiple crustaceans. Overall, these epitopes could enhance our understanding of crab allergens, which lay the foundation for a cross-reaction.

Characterization, Epitope Identification, and Cross-reactivity Analysis of Tropomyosin: An Important Allergen of Crassostrea angulata

Oyster is a common shellfish product in China, which is associated with food allergy. However, there is still lack of research on allergens in oysters. In this study, tropomyosin (TM), an important allergen of Crassostrea angulata, was purified and identified by mass spectrometry. Subsequently, TM was cloned and expressed, with a sequence of size 852 bp, encoding 284 amino acid residues. The results of circular dichroism, digestion assay, inhibition enzyme-linked immunosorbent assay, and basophil activation test showed that recombinant TM had similar physicochemical properties and immunological properties to native TM. Furthermore, two conformational mimotopes were obtained and 10 IgE linear epitopes were verified. Meanwhile, different degrees of cross-reactivity were observed between C. angulata TM and the other 8 shellfish TMs using antibodies and serological analysis, which may relate to the 3 conserved epitope regions. These findings are expected to provide a theoretical basis for the molecular diagnosis of oyster allergy and cross-reactivity among shellfish.

Evaluation of Allergic Cross-Reactivity Among Fishes by Microfluidic Chips and MALDI-TOF MS

Fish is one of the most common foods that cause allergic reactions. The study of cross-reactivity among fishes using mass spectrometry (MS) is still limited. We developed a strategy using microfluidic chips coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to evaluate cross-reactivity among fishes. The protocol employed commercial magnetic beads functionalized with anti-human IgE antibodies to carry out the IgEs immunomagnetic separation in blood samples, followed by the capture of allergens from seafood protein extracts in a single-straight microfluidic channel. After elution, the captured allergens were digested and identified by MALDI-TOF MS and high-performance liquid chromatography-tandem mass spectrometry and validated by enzyme-linked immunosorbent assay (ELISA). An investigation of the reproducibility revealed that the protocol can sense well the allergens in a food matrix. Seven fish species were analyzed to evaluate the allergic cross-reactivity among fishes. The commercial ELISA test gave consistent results with the presently developed strategy when the same allergenicity test was performed. Parvalbumins were detected from five of the seven analyzed fishes. The sequence alignment of parvalbumins revealed that the similarity of parvalbumins identified from the analyzed fishes is larger than 64%. Boiling may reduce the allergenicity of fish, as demonstrated by a marginal diminish in the parvalbumin content of crucian carp (Carassius carassius) muscle when boiling with water. The method can potentially be used to predict allergic cross-reactivity among fish species, provide advice and guidance to individuals with a history of seafood allergy, and ensure food safety in the food allergy community.

The Risk of Undeclared Allergens on Food Labels for Pediatric Patients in the European Union

The dietary avoidance of allergens has been widely recognized as the key intervention in the management of food allergies, but the presence of undeclared allergens makes compliance difficult. The aim of this study was to analyze the presence of undeclared allergens in food labeling through RASFF notifications in the European Union, focusing on those allergens that frequently affect the pediatric population and the implicated products, so as to provide useful information for its risk evaluation and the development of educational materials for patients. The results showed milk (20.5%), gluten (14.8%), and nuts (10.9%) to be the pediatric allergens with higher presences. In 80% of the notifications concerning milk and milk derivatives, the specific compound present (lactose or lactoprotein) was not identified. They were mainly present in cereal and bakery products, prepared dishes and snacks, and cacao and confectionery products, all of which are frequently consumed by the pediatric population. The large quantity (7.6%) of undeclared allergens in “free-from-allergen” products was also remarkable, especially in regard to the supposedly not-present allergens. Undeclared allergens in food products pose an evident risk for allergic patients and knowledge of them should take a relevant role in a patient’s nutritional education. It is also necessary to raise awareness among manufacturers and safety authorities.