Development of mouse model for oral allergy syndrome to identify IgE cross-reactive pollen and food allergens: ragweed pollen cross-reacts with fennel and black pepper

Oral allergy syndrome (OAS) is an IgE-mediated immediate food allergy that is localized to the oral mucosa. Pollen food allergy syndrome (PFAS), a pollinosis-associated OAS, is caused by cross-reactivity between food and pollen allergens. However, we need to more precisely understand the underlying pathogenesis of OAS/PFAS. In the present study, we developed a method to comprehensively identify cross-reactive allergens by using murine model of OAS and protein microarray technology. We focused on lip angioedema, which is one of the most common symptoms of OAS, and confirmed that mast cells reside in the tissues inside the lower lip of the mice. Interestingly, when the food allergen ovalbumin (OVA) was injected inside the lower lip of mice with high levels of OVA-specific IgE followed by an intravenous injection of the Evans blue dye, we found immediate dye extravasation in the skin of the neck in a mast cell-dependent manner. In addition, the degree of mast cell degranulation in the oral cavity, reflecting the severity of oral allergic responses, can be estimated by measuring the amount of extravasated dye in the skin. Therefore, we used this model of OAS to examine IgE cross-reactive allergens in vivo. Protein microarray analysis showed that serum IgE from mice intraperitoneally sensitized with ragweed pollen, one of the major pollens causing pollinosis, bound highly to protein extracts from several edible plants including black peppercorn and fennel. We confirmed that the levels of black pepper-specific IgE and fennel-specific IgE were significantly higher in the serum from ragweed pollen-sensitized mice than in the serum from non-sensitized control mice. Importantly, analysis of murine model of OAS showed that the injection of black pepper or fennel extract induced apparent oral allergic responses in ragweed pollen-sensitized mice. These results indicate IgE cross-reactivity of ragweed pollen with black pepper and fennel. In conclusion, we developed mouse model of OAS to identify IgE cross-reactive pollen and food allergens, which will help understand the pathogenesis of OAS/PFAS.

Comprehensive Review on Banana Fruit Allergy: Pathogenesis, Diagnosis, Management, and Potential Modification of Allergens through Food Processing

The pulp of the banana fruit is rich in bioactive compounds like dietary fibers, low glycemic carbohydrates, natural sugars, vitamins, minerals and antioxidants. These beneficial compounds are responsible for the proper functioning of immune system and enhance prevention against various deadly diseases like cancer, diabetes and heart diseases. Despite having, positive effects, the fruit are recognized as an important source for causing allergy to 0.6% of people in general population and up to 67 and 46% for people with asthma or atopic dermatitis. Fruit allergy is one of the most common food allergies witnessed worldwide. Banana fruit allergy results from the abnormal immune response to the banana proteins soon after its consumption. Symptoms range from oral allergy syndrome (OAS) to the life-threatening anaphylaxis. IgE reactivity of banana is associated with different proteins of which six proteins have been identified as major allergens, viz., Mus a1 (Profilin-actin binding protein), Mus a 2 (Class 1 chitinase), Mus a 3 (Nonspecific lipid transfer protein), Mus a 4 (Thaumatin like protein), Mus a 5 (Beta 1,3 glucanase) and Mus a 6 (Ascorbate peroxidase). This review focuses on pathogenesis, clinical features, diagnosis, and different food processing methods to mitigate the allergenicity of banana fruit.

Meat Allergy: A Ticking Time Bomb

Food allergies are relatively prevalent, but mammalian meat allergy remains uncommon and represents an important, potentially acute healthcare risk. This risk is partly because both clinicians and the public lack awareness of this serious allergy, which is unique in three important ways: it incurs a delayed reaction, it is induced by a carbohydrate rather than a protein, and it is linked to tick bites. Although various symptoms are possible, its unique presentation means that mammalian meat allergy is often presented to the dermatologist. We review this challenging subject, which is particularly salient considering the unique connection between ticks and mammalian meat allergy, the expanding tick territory, and the dependency by so many on meat products, not only in the diet but also in medications and medical devices.

The Role of Molecular Allergens in the Diagnosis of Cat-Pork Syndrome: An Unusual Case Report

Cat-pork syndrome is a rare condition, with few cases reported in the literature. This syndrome is justified by the homology between serum albumins from cat and pork. Evidence suggests that a primary sensitization to cat serum albumin Fel d 2 occurs, followed by allergic reactions after ingestion of pork meat containing serum albumin Sus s 1. Due to homology between other mammalian serum albumins, reactions with other meats can also be present. We report a well-documented case report of a patient with cat-pork syndrome, with initial mild and non-specific manifestations to well-cooked pork that were overlooked. Component resolved diagnosis was essential to establish the diagnosis, which confirmed the involvement of Fed 2 and Sus s 1, but less relevant in helping to define avoidance diets, since the sensitization profile was not in accordance with clinical manifestations.

Associations between grass pollen exposures in utero and in early life with food allergy in 12-month-old infants

Birth during pollen seasons may influence food allergy risk but no study has assessed pollen exposure. Using the HealthNuts population-based cohort of 5276 infants, we assessed grass pollen exposures, in utero and up to the first 6 months of life, on hen's egg, sesame and peanut allergy outcomes at 12 months. Cumulative pollen exposure in the first 7 days of life increased risk of peanut sensitization aMOR (adjusted multinomial odds ratio) = 1.21 (95% CI: 1.01-1.44). Exposure between first 4-6 months of life increased risk of hen's egg aMOR = 1.02 (95% CI: 1.004-1.04) and sensitization to all foods aMOR = 1.02 (95% CI: 1.003-1.04). Grass pollen exposure was associated with food challenge diagnosed food allergy, but only among infants with a maternal history of food allergy. Exposure to grass pollen in the intrauterine period and infancy may be important but more studies are needed to replicate these findings.

Occupational inhalant allergy in food handling occupations

PURPOSE OF REVIEW

Review article on recent developments on inhalant food allergens associated with occupational respiratory allergy and asthma.

RECENT FINDINGS

This review has found that occupational inhalant allergy in food handling occupations is a common and recognisable clinical entity (class 3 food allergy) in high-risk food occupations such as bakeries and seafood processing. Aerosolised food proteins from plant or animal food sources, additives and biological food contaminants cause occupational sensitization, rhinitis and asthma. The risk of allergy may be enhanced across the food value chain as a result of food processing techniques including the introduction of new food allergens in the food matrix. Occupational food allergy and asthma can be prevented by improved health-based exposure standards, workplace control measures, education and training activities, and early diagnosis accompanied with exposure reduction.

SUMMARY

Future studies need to focus on exposure-response studies to establish improved exposure limits especially for flour dust, the relevance of cooked vs raw foods in influencing risk, identifying and characterising major inhalant food allergens accompanied with component resolved diagnostic approaches, and evaluating the effectiveness of interventions for common high-risk food sensitizers causing occupational rhinitis and asthma.

The First Case of Erythritol-Induced Anaphylaxis in Korea

Erythritol is a natural sugar alcohol found in some fruits and fermented foods, which is used as a dietary sweetener because it has few calories. Here, we describe a 36-year-old woman who experienced anaphylaxis upon ingestion of an erythritol-containing drink. She presented to the emergency department with dyspnea and angioedema after drinking a peach-containing diet beverage. Her blood pressure dropped to 70/40 mmHg and the symptoms improved after administration of an antihistamine, glucocorticoid, and epinephrine. After 10 days, she drank another peach-containing diet beverage and experienced urticaria. No serum-specific immunoglobulin E findings were observed, including against peach components. A skin prick test (SPT) was performed using a peach, the two ingested diet beverages, and another peach-containing beverage. The SPT results for the peach and the peach-containing product were negative, but the wheal sizes for the two diet beverages were > 3 mm. The diet beverages contained erythritol as a food additive. The SPT result was positive for erythritol. The patient was diagnosed with anaphylaxis to erythritol and was instructed to avoid foods containing erythritol. She was prescribed a self-injectable epinephrine pen. To our knowledge, this is the first case of erythritol-induced anaphylaxis in Korea. Physicians should be aware of the possibility of allergic reactions to food additives, and additives should be evaluated to prevent the recurrence of symptoms.

[Food sensitivities of the digestive tract-Part 2: Food intolerances]

Adverse reactions to food affect about one third of the population. They are based on very different mechanisms and are triggered by specific foods. They are divided into food intolerances, which manifest mainly in the gastrointestinal tract and food allergies, which can also cause extraintestinal symptoms and have an immunological genesis. In adults, food intolerances are significantly more common than food allergies with a prevalence of approximately 10-20%. The most important food intolerances are sugar intolerances, such as lactose and fructose intolerance but intolerances to wheat also play an increasing role. The diagnostics of food intolerances require extensive exclusion diagnostics, whereby in particular irritable bowel syndrome and intestinal dysbiosis must be differentiated. The therapy of food intolerance is primarily based on a targeted elimination diet. In this advanced education article the most important food intolerances are discussed.

De Novo Food Allergy in Pediatric Recipients of Liver Transplant

ABSTRACT

Allergic and atopic conditions, including food allergy, asthma, eczema and eosinophilic disease of the gastrointestinal tract after liver transplant in previously non-allergic children have been increasingly described. After a liver transplant, children can present mild to severe reactions to food allergens (ie, from urticaria-angioedema to life-threatening anaphylactic reactions). De novo post-transplant food allergy may become clinically evident in children who undergo liver transplant between a few months and a few years of transplant. The present narrative review aims to describe the spectrum of de novo post-transplant food allergy development, the current theories of pathogenesis, risk factors and to suggest possible clinical management strategies.

Soybean allergy: characteristics, mechanisms, detection and its reduction through novel food processing techniques

Human beings have consumed soybean as an excellent food source for thousand years due to its rich protein, fatty acids, minerals, and fibers. However, soybeans were recognized as one of the big eight allergens resulting in allergic symptoms and even could lead to death. With the increasing demand for soybean products, the challenges caused by soybean allergy need to be solved urgently. This review detailly described the pathogenesis and clinical characteristics of soybean allergy, and also the advantages and disadvantages of four different diagnostic methods were summarized. The major soybean allergens and their structures were summarized. Three types of soybean allergy including Type I, III, and IV, which could trigger allergic reactions were reported in this review. Summary in four different diagnostic methods showed that double-blind, placebo-controlled food challenge is recognized as a gold standard for diagnosing soybean allergy. Three types of processing techniques in reducing soybean allergy were discussed, and the results concluded that some novel food processing techniques such as ultrasound, cold-plasma treatment, showed potential application in the reduction of soybean allergenicity. Further, some suggestions regarding the management and treatment of food allergies were addressed in this review.

An Overview of Environmental Risk Factors for Food Allergy

IgE-mediated food allergy is an increasing public health concern in many regions around the world. Although genetics play a role in the development of food allergy, the reported increase has occurred largely within a single generation and therefore it is unlikely that this can be accounted for by changes in the human genome. Environmental factors must play a key role. While there is strong evidence to support the early introduction of allergenic solids to prevent food allergy, this is unlikely to be sufficient to prevent all food allergy. The purpose of this review is to summarize the evidence on risk factors for food allergy with a focus the outdoor physical environment. We discuss emerging evidence of mechanisms that could explain a role for vitamin D, air pollution, environmental greenness, and pollen exposure in the development of food allergy. We also describe the recent extension of the dual allergen exposure hypothesis to potentially include the respiratory epithelial barrier in addition to the skin. Few existing studies have examined the relationship between these environmental factors with objective measures of IgE-mediated food allergy and further research in this area is needed. Future research also needs to consider the complex interplay between multiple environmental factors.

Clinical features of anaphylaxis in children

Background: Despite the considerable increase in anaphylaxis frequency, there are limited studies on clinical features of anaphylaxis in children in developing countries. Objective: We aimed to analyze the demographic and clinical features of anaphylaxis in children in Turkey by comparing different age groups and triggers. Methods: Medical records of 147 children, ages 0-18 years, diagnosed with anaphylaxis between 2010 and 2019 were retrospectively analyzed. Results: The mean ± standard deviation age at first anaphylaxis episode was 5.9 ± 5.2 years, with a male predominance (63.9%); 25.2% were infants and 52.4% were < 6 years of age at their first anaphylaxis episode; 78.2% were atopic, with the highest frequency in children with food-induced anaphylaxis (FIA). The home (51.7%) was the most frequent setting. The overall leading cause of anaphylaxis was food (44.2%), which was more frequent at < 6 years of age, followed by drugs (28.6%) and bee venom (22.4%), both were more frequent among older children (>6 years). The patients with venom allergy had the highest rate of rapid onset of symptoms (p < 0.001). Gastrointestinal symptoms were observed significantly more in infants (48.6%) and in children with FIA (38.5%); cardiovascular symptoms were more frequently observed in children > 6 years of age (48.6%) and in children with drug-induced anaphylaxis (64.3%). Although recurrent anaphylaxis was reported for 23.1% of the patients, it was highest in the patients with FIA (35.9%). Overall, only 47.6% of the patients received epinephrine in the emergency department (ED) and 27.3% were referred to an allergy specialist, with the patients with FIA having the lowest rate for both, 32.3% and 10.8%, respectively. Children with drug-induced anaphylaxis had the highest rate of severe anaphylaxis (57.1%). Conclusion: There is a need to improve anaphylaxis recognition and management in all children regardless of age and trigger. Inadequate treatment was most evident in infants and patients with FIA.

Mammalian meat allergy emerges after tick bite: the alpha-gal syndrome

Alpha-gal syndrome (AGS) is a hypersensitivity reaction to mammalian meat that develops after tick bite exposure. AGS was first described in 2009 and testing for the allergy has become available in the last decade. We report the case of a 56-year-old farmer with a history of frequent lone star tick bites who presented with a 7-year history of diffuse urticaria occurring hours after eating red meat. AGS is likely underdiagnosed because of the unusual presentation of the allergy, historic lack of available testing, and deficiency of physician knowledge about the condition. Recognition of AGS is important both to help alleviate symptom burden and to avoid iatrogenesis. Patients with AGS should not receive products containing mammalian products, such as cat-gut suture, porcine-derived heart valves, and bovine-derived vaccines. Patients with AGS may present in a variety of clinical environments and physicians of all kinds should be able to recognise the symptoms.

Rapid and accurate electrochemical sensor for food allergen detection in complex foods

Food allergies are estimated to affect about 2-5% of adults and 6-8% of children, globally. Currently, the most effective strategy for food allergy management is stringent avoidance of the offending allergen. Unlike other major food allergens, soy is uniquely challenging to avoid due to its prevalence and insidiousness in a wide variety of foods, such as infant formulas. Recently, we demonstrated a simple, accurate, and consumer-friendly sensor using molecularly imprinted polymers (MIPs) for rapid detection of soy allergenic tracers in complex food matrices at clinically relevant levels. In this work, we build on these findings by subjecting MIP-based soy allergen sensors to test trials in 42 different food products, representing over 300 ingredients. Foods were selected based on their compositional complexity to capture a wide range of preparatory methods and processing conditions. In each case, the Allergy Amulet correctly reported on the presence or absence of soy allergen tracer in investigated samples and were subjected to immunoassay confirmatory analysis. The outcome of this research will help resolve persistent difficulties with commercial technologies in detecting allergenic tracers with minimal cross-interference in foods, and will give those with soy allergies the ability to easily, rapidly, and accurately identify and avoid foods with soy allergens.

A High-Sodium Diet Modulates the Immune Response of Food Allergy in a Murine Model

Mounting evidence demonstrates that a high-salt diet (HSD) not only affects hemodynamic changes but also disrupts immune homeostasis. The T helper 17 (Th17) and regulatory T cells (Tregs) are susceptible to hypersalinity. However, research on the influence of sodium on Th2-mediated food allergies remains scarce. We aimed to investigate the effect of dietary sodium on the immune response to food allergies. Mice maintained on an HSD (4% NaCl), low-salt diet (LSD; 0.4% NaCl), or control diet (CTRL; 1.0% NaCl) were orally sensitized with ovalbumin (OVA) and a cholera toxin (CT) adjuvant, and then subjected to an intragastric OVA challenge. OVA-specific immunoglobulin G (IgG), IgG1, IgG2a, and IgE antibodies were significantly higher in the HSD group than in the CTRL group (p < 0.001, p < 0.05, p < 0.01, and p < 0.05, respectively). Mice on HSD had significantly higher interleukin (IL)-4 levels than the CTRL group (p < 0.01). The IL-10 levels were significantly lower in the HSD group than in the CTRL group (p < 0.05). The serum levels of interferon-γ (IFN-γ), sodium, and chloride did not differ among the three groups. This study indicates that excessive salt intake promotes Th2 responses in a mouse model of food allergy.

Current Insights into Immunology and Novel Therapeutics of Atopic Dermatitis

Atopic dermatitis (AD) is one of the most prevalent inflammatory disease among non-fatal skin diseases, affecting up to one fifth of the population in developed countries. AD is characterized by recurrent pruritic and localized eczema with seasonal fluctuations. AD initializes the phenomenon of atopic march, during which infant AD patients are predisposed to progressive secondary allergies such as allergic rhinitis, asthma, and food allergies. The pathophysiology of AD is complex; onset of the disease is caused by several factors, including strong genetic predisposition, disrupted epidermal barrier, and immune dysregulation. AD was initially characterized by defects in the innate immune system and a vigorous skewed adaptive Th2 response to environmental agents; there are compelling evidences that the disorder involves multiple immune pathways. Symptomatic palliative treatment is the only strategy to manage the disease and restore skin integrity. Researchers are trying to more precisely define the contribution of different AD genotypes and elucidate the role of various immune axes. In this review, we have summarized the current knowledge about the roles of innate and adaptive immune responsive cells in AD. In addition, current and novel treatment strategies for the management of AD are comprehensively described, including some ongoing clinical trials and promising therapeutic agents. This information will provide an asset towards identifying personalized targets for better therapeutic outcomes.

Gender differences in food allergy depend on the PPAR γ/NF-κB in the intestines of mice

AIMS

Epidemiology shows that gender affects the incidence of food allergy. However, there is a lack of evidence of gender differences in food allergies and little is known about the mechanisms. The aim of this study was to excavate potential reasons for gender differences in food allergy based on estrogen.

MAIN METHODS

Female and male BALB/c mice sensitized with ovalbumin (OVA) were established to analyze the difference in food allergy. The systemic anaphylactic, including OVA-specific IgE, OVA-specific IgG, histamine, and cytokines, was assessed using an enzyme-linked immunosorbent assay (ELISA). ELISA also detected the estradiol in serum. Western blotting and immunofluorescence were used to detect the estrogen receptor. Peroxisome proliferator-activated receptor gamma (PPARγ) implicated in immune homeostasis and nuclear factor kappa-B (NF-κB) were determined by western blotting. Immunohistochemistry and hematoxylin-eosin (H&E) staining were used to detect zonula occludens-1 (ZO-1), tryptase, forkhead box protein P3 (Foxp3), and intestinal morphology, respectively.

KEY FINDINGS

Female mice were more vulnerable to food allergy. Female mice treated with OVA did exhibit more serious systemic anaphylaxis than male mice. We observed increased levels of estradiol in serum, estrogen receptor, NF-κB, and decreased levels of PPAR γ in female mice. Furthermore, the intestinal mucosal integrity and intestinal permeability were more impaired in female mice treated with OVA than male mice.

SIGNIFICANCE

Clarify the mechanism of gender differences in food allergies can provide targets in female mice and provide personalized diagnosis, management, and treatment of food allergy for female mice.

The Common Cichory (Cichorium intybus L.) as a Source of Extracts with Health-Promoting Properties-A Review

Natural products are gaining more interest recently, much of which focuses on those derived from medicinal plants. The common chicory (Cichorium intybus L.), of the Astraceae family, is a prime example of this trend. It has been proven to be a feasible source of biologically relevant elements (K, Fe, Ca), vitamins (A, B1, B2, C) as well as bioactive compounds (inulin, sesquiterpene lactones, coumarin derivatives, cichoric acid, phenolic acids), which exert potent pro-health effects on the human organism. It displays choleretic and digestion-promoting, as well as appetite-increasing, anti-inflammatory and antibacterial action, all owing to its varied phytochemical composition. Hence, chicory is used most often to treat gastrointestinal disorders. Chicory was among the plants with potential against SARS-CoV-2, too. To this and other ends, roots, herb, flowers and leaves are used. Apart from its phytochemical applications, chicory is also used in gastronomy as a coffee substitute, food or drink additive. The aim of this paper is to present, in the light of the recent literature, the chemical composition and properties of chicory.

T and B Lymphocyte Transcriptional States Differentiate between Sensitized and Unsensitized Individuals in Alpha-Gal Syndrome

The mechanisms of pathogenesis driving alpha-gal syndrome (AGS) are not fully understood. Differences in immune gene expression between AGS individuals and non-allergic controls may illuminate molecular pathways and targets critical for AGS development. We performed immune expression profiling with RNA from the peripheral blood mononuclear cells (PBMCs) of seven controls, 15 AGS participants, and two participants sensitized but not allergic to alpha-gal using the NanoString nCounter PanCancer immune profiling panel, which includes 770 genes from 14 different cell types. The top differentially expressed genes (DEG) between AGS subjects and controls included transcription factors regulating immune gene expression, such as the NFκB pathway (NFKBIA, NFKB2, REL), antigen presentation molecules, type 2/allergic immune responses, itch, and allergic dermatitis. The differential expression of genes linked to T and B cell function was also identified, including transcription factor BCL-6, markers of antigen experience (CD44) and memory (CD27), chemokine receptors (CXCR3, CXCR6), and regulators of B-cell proliferation, cell cycle entry and immunoglobulin production (CD70). The PBMCs from AGS subjects also had increased TNF and IFN-gamma mRNA expression compared to controls. AGS is associated with a distinct gene expression profile in circulating PBMCs. DEGs related to antigen presentation, antigen-experienced T-cells, and type 2 immune responses may promote the development of alpha-gal specific IgE and the maintenance of AGS.

[Food protein-induced enterocolitis syndrome (FPIES) : a poorly known type of food allergy]

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated food allergy. Its pathophysiology is still poorly understood. FPIES mainly affects infant and young children, although cases have been reported in adults. Its symptomatology is restricted to gastrointestinal manifestations and the onset of allergic reaction subsequent to exposure is delayed. The most common culprit for children is cow's milk. Initial clinical presentation of FPIES is oftentimes acute, though it can also be chronic. Diagnosis relies on clinical criteria, which have been recently redefined and subject to international consensus. Through two clinical cases, this report aims to describe the characteristics of this emerging disease as well as delineate the treatment thereof.

'Diagnosing food protein-induced enterocolitis syndrome'

Food protein-induced enterocolitis syndrome is still a mysterious disease, pathogenically poorly characterized, although the first FPIES case has been described in 1967. Mainly, food protein-induced enterocolitis syndrome diagnosis is based on clinical history. The oral food challenge remains the gold standard to confirm the diagnosis, especially in particular situations. Although there are no diagnostic laboratory or imaging tests which are specific for diagnosis, they could, however, sometimes be helpful to rule out clinical conditions which are similar to food protein-induced enterocolitis syndrome reactions. The purpose of this review is to define the clinical features of FPIES and to summarize the current available tools for the diagnosis of FPIES. This review is intended to be a practical guide for the clinician facing a patient with food protein-induced enterocolitis syndrome avoiding delayed diagnosis with unnecessary laboratory tests and detrimental treatments. Moreover, it highlights the unmet needs in diagnosis that require urgent attention from the scientific community to improve the management of patients with FPIES.

Applications of Mouse Models to the Study of Food Allergy

Mouse models of allergic disease offer numerous advantages when compared to the models of other animals. However, selection of appropriate mouse models is critical to advance the field of food allergy by revealing mechanisms of allergy and for testing novel therapeutic approaches. All current mouse models for food allergy have weaknesses that may limit their applicability to human disease. Aspects such as the genetic predisposition to allergy or tolerance from the strain of mouse used, allergen dose, route of exposure (oral, intranasal, intraperitoneal, or epicutaneous), damage of the epithelial barrier, use of adjuvants, food matrix effects, or composition of the microbiota should be considered prior to the selection of a specific murine model and contemplated according to the intended purpose of the study. This chapter reviews our current knowledge on the application of mouse models to food allergy research and the variables that may influence the successful development of each type of model.