Transglutaminase-mediated cross-linking of a peptic fraction of omega-5 gliadin enhances IgE reactivity in wheat-dependent, exercise-induced anaphylaxis

Food allergy endotypes revisited

In the last century, food allergy has become recognized as an increasingly prevalent and heterogeneous condition. Advances in biomedical technology have revealed complex genetic, environmental, immune, and metabolic pathways underlying the pathogenesis of food-allergic disorders. These findings permit classification of distinct food allergy endotypes with unique pathophysiologic features. In this review, we suggest that these endotypes of food-allergic disorders should be defined on the basis of (1) whether or not the allergic antibody IgE plays an essential role in disease pathogenesis, (2) the molecular features of the allergen (protein vs carbohydrate), and (3) the molecular markers associated with prognosis, severity, or clinical presentation. Beyond these broad categories, additional subtypes with unique mechanistic characteristics are discussed.

When allergies have no name: is idiopathic anaphylaxis driven by co-factors?

Idiopathic anaphylaxis (IA) is a severe allergic reaction without identifiable external triggers, presenting significant challenges in diagnosis and management. However, growing evidence suggests that many cases classified as idiopathic may actually be driven by cofactors such as exercise, hormonal fluctuations, medications, or hidden allergens. This mini-review explores the evolving understanding of IA, highlighting the role of these cofactors in triggering or amplifying anaphylactic reactions. It emphasizes how advances in diagnostic tools, including component-resolved diagnostics, are helping to identify previously undetected allergens, leading to more accurate diagnoses and reducing the prevalence of true idiopathic cases. As our knowledge of anaphylaxis and its underlying mechanisms deepens, the need for comprehensive evaluations that account for cofactor involvement becomes increasingly clear. Continued research in this area is essential to improve patient outcomes and better manage this complex condition.

Cofactors in food anaphylaxis in adults

Around 25% to 50% of food-induced allergic reactions in adults cause anaphylaxis, and epidemiologic evidence suggests that food is the most common cause of anaphylaxis. Reaction severity is unpredictable, and patients will often experience reactions of variable severity, even to an identical exposure (both dose and allergen). A common explanation for this phenomenon has been the impact of "cofactors"-factors that might contribute to reaction severity independent of the allergen exposure. Cofactors can influence reaction severity in 2 ways: either by reducing the reaction threshold (ie, the dose needed to trigger any symptoms) so that patients have no symptoms in the absence of the cofactor and only react with the cofactor present, or by increasing reaction severity such that individuals have only mild symptoms in the absence of the cofactor, but a more severe reaction when the cofactor is present. Indeed, the same patient may have reactions with different cofactors or even need more than one cofactor to develop a severe reaction. Cofactors reportedly play a role in approximately 30% of anaphylaxis reactions in adults. Exercise, nonsteroidal, anti-inflammatory drugs, alcohol, and sleep deprivation are the most frequent cofactors reported. Routine evaluation of the possible involvement of cofactors is essential in managing patients with food anaphylaxis: in patients with a suggestive history but a negative oral food challenge, cofactors should be taken into account to provide appropriate advice to reduce the risk of future anaphylaxis.

IgE-Binding and Immunostimulating Properties of Enzymatic Crosslinked Milk Proteins as Influenced by Food Matrix and Digestibility

Dairy foods are essential in the diet, although in some susceptible individuals they may cause allergy to cow's milk proteins. Therefore, alternative methods are sought to reduce their allergenicity. Transglutaminase (TG) is widely used in dairy products mainly to improve texture. Although it has been claimed that TG can be used to modify the digestibility and allergenicity of foods, its impact within a real matrix has been rarely studied. The aim of this work was to assess the allergenic potential of crosslinked skim milk (SM), milk casein fraction (CN), and whey protein (WP). To this purpose, inhibition ELISA with sera from milk allergic patients, in vitro activation tests of mouse mast cells and splenocytes, and simulated gastrointestinal digestion assays were performed. The results showed that cross-linking increased the binding of IgE to WP, but decreased IgE-binding to SM and CN. However, no differences were observed in the ability of cross-linked proteins to induce mast cell degranulation compared to native proteins. The cross-linking of SM and CN reduced Th2 cytokine release from the splenocytes of sensitized mice. All TG-treated samples exhibited more resistance to in vitro digestion than the untreated proteins and the human IgE binding capacity after digestion was higher. In conclusion, TG treatment of milk proteins does not reduce the risk of eliciting allergic symptoms in cow's milk allergic patients.

Food-Dependent Exercise-Induced Wheals, Angioedema, and Anaphylaxis: A Systematic Review

BACKGROUND

Food-dependent exercise-induced wheals, angioedema, and anaphylaxis remain insufficiently characterized.

OBJECTIVE

We systematically reviewed the literature on clinical manifestations, laboratory investigations, culprit foods, triggering exercise, comorbidities, and treatment outcomes.

METHODS

Using predefined search terms and Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) recommendations, we searched 3 electronic databases to identify relevant literature published before July 2021.

RESULTS

Of 722 patients (median age 25 years; 55.4% male) from 231 studies (43 cohort studies, 15 cases series, and 173 case reports), 79.6% and 3.7% had anaphylaxis with and without wheals and/or angioedema, respectively. The remaining 16.6% had wheals and/or angioedema without anaphylaxis. The duration from eating to exercising and from exercising to symptom onset ranged from 5 minutes to 6 hours (median 1 hour) and from 5 minutes to 5 hours (median 30 minutes), respectively, and virtually all patients exercised within 4 hours after eating and developed symptoms within 1 hour after exercising. Wheat was the most common culprit food. Running was the most common trigger exercise. Most patients were atopic, and 1 in 3 had a history of urticaria. Aspirin and wheat-based products were the most frequent augmenting factors. On-demand antihistamines, corticosteroids, and epinephrine were commonly used and reported to be effective. Patients who stopped eating culprit foods before exercise no longer developed food-dependent exercise-induced allergic reactions.

CONCLUSIONS

Food-dependent exercise-induced allergic reactions are heterogeneous in their clinical manifestations, triggers, and response to treatment. Patients benefit from avoidance of culprit foods before exercise, which highlights the need for allergological diagnostic workup and guidance.

The Fate of IgE Epitopes and Coeliac Toxic Motifs during Simulated Gastrointestinal Digestion of Pizza Base

Understanding how food processing may modify allergen bioaccessibility and the evolution of immunologically active peptides in the gastrointestinal tract is essential if knowledge-based approaches to reducing the allergenicity of food are to be realised. A soy-enriched wheat-based pizza base was subjected to in vitro oral–gastro–duodenal digestion and resulting digests analysed using a combination of sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and mass spectrometry (MS). The digestion profile of pizza base resembled that of bread crust where higher temperatures during baking reduced protein solubility but still resulted in the generation of a complex mixture of peptides. MS profiling showed numerous peptides carrying IgE epitopes, and coeliac toxic motifs were in excess of 20–30 residues long and were only released after either 120 min of gastric digestion or a combination of gastric and duodenal digestion. In silico prediction tools showed an overestimated number of cleavage sites identified experimentally, with low levels of atypical peptic and chymotryptic cleavage sites identified particularly at glutamine residues. These data suggest that such alternative pepsin cleavage sites may play a role in digestion of glutamine-rich cereal foods. They also contribute to efforts to provide benchmarks for mapping in vitro digestion products of novel proteins which form part of the allergenicity risk assessment.

Clinical features and outcomes of patients with wheat-dependent exercise-induced anaphylaxis: a retrospective study

Background

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a serious and potentially life-threatening form of wheat allergy. Further episodes can only be prevented by avoiding wheat ingestion or avoiding exercise after wheat intake. Anaphylaxis may recur in some patients post-diagnosis. This study aimed to analyze the clinical features and management/outcomes of WDEIA in China.

Methods

We retrospectively analyzed the clinical characteristics, and laboratory testing of 197 patients with WDEIA. After diagnosis, the patients were followed up as outpatients to evaluate dietary/exercise choice and clinical outcomes.

Results

Among the 197 WDEIA patients (median age, 37 years), 53.8% were male and 28.4% had other allergic disorders. The median duration of anaphylaxis before diagnosis was 16 months. Significant delays in diagnosis (> 1 years) were recorded in 52.7% of the patients, which has not decreased by years (P = 0.064). Exercise (83.8%), alcohol (12.2%), and nonsteroidal anti-inflammatory drugs (7.1%) were the most common cofactors. The most common clinical features were urticaria (100%), loss of consciousness (82.7%), dyspnea (50.8%), and hypotension (47.2%). Of the 197 eligible patients, 155 responded (78.7%), and 124 (80.0%) of which had no anaphylaxis post-diagnosis. A wheat-free diet prevented future anaphylaxis in 91.7% of the patients, followed by the avoidance of wheat combined with exercise (87%) and reduced wheat intake combined with exercise avoidance (80.5%).

Conclusion

The diagnosis of WDEIA is frequently delayed. Therefore, when patients present with unexplained anaphylaxis, the possibility of WDEIA should be considered. A wheat-free diet or avoiding wheat combined with exercise or reduced wheat combined with exercise avoidance helps to significantly reduce the onset of future anaphylaxis. However, approximately one-fifth of patients continue to experience anaphylaxis post-diagnosis. Thus, these patients must always carry epinephrine autoinjectors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00702-1.

The Effector Function of Allergens

Allergens are antigens that generate an IgE response (sensitization) in susceptible individuals. The allergenicity of an allergen can be thought of in terms of its ability to sensitize as well as its ability to cross-link IgE/IgE receptor complexes on mast cells and basophils leading to release of preformed and newly formed mediators (effector activity). The identity of the allergens responsible for sensitization may be different from those that elicit an allergic response. Effector activity is determined by (1) the amount of specific IgE (sIgE) and in some circumstances the ratio of sIgE to total IgE, (2) the number of high affinity receptors for IgE (FcεR1) on the cell surface, (3) the affinity of binding of sIgE for its epitope and, in a polyclonal response, the collective avidity, (4) the number and spatial relationships of IgE binding epitopes on the allergen and (5) the presence of IgG that can bind to allergen and either block binding of sIgE and/or activate low affinity IgG receptors that activate intracellular inhibitory pathways. This review will discuss these important immunologic and physical properties that contribute to the effector activity of allergens.

Nutrition and urticaria

Urticaria is a distressing dermatologic condition for many. Although the wheals of urticaria are characteristically evanescent, lasting less than 24 hours, patients tend to have recurrent episodes. Hives that last less than 6 weeks are considered acute urticaria. Acute urticaria does not routinely require supplementary work-up because the history often identifies a convincing, inciting allergen. Chronic urticaria is defined as episodes that occur for longer than 6 weeks, and there is often not an easily identifiable trigger. For both acute and chronic urticaria, patients frequently report food as a precipitating cause. For acute urticaria, the foods that are associated with true allergies, such as nuts and shellfish, are the most frequent offenders. The relationship between diet and chronic urticaria is not as firmly defined. Many patients unnecessarily restrict their diets, so it becomes the role of dermatologists to help patients identify if there is a reproducible link between their symptoms and their dietary exposures. The literature suggests that diets free from pseudoallergens and histamine-releasing foods may attenuate urticaria. Supplements such as fats, vitamin D, iron, and flavonoids have also been studied and may diminish symptoms.

Are Physicochemical Properties Shaping the Allergenic Potency of Plant Allergens?

This review searched for published evidence that could explain how different physicochemical properties impact on the allergenicity of food proteins and if their effects would follow specific patterns among distinct protein families. Owing to the amount and complexity of the collected information, this literature overview was divided in two articles, the current one dedicated to protein families of plant allergens and a second one focused on animal allergens. Our extensive analysis of the available literature revealed that physicochemical characteristics had consistent effects on protein allergenicity for allergens belonging to the same protein family. For example, protein aggregation contributes to increased allergenicity of 2S albumins, while for legumins and cereal prolamins, the same phenomenon leads to a reduction. Molecular stability, related to structural resistance to heat and proteolysis, was identified as the most common feature promoting plant protein allergenicity, although it fails to explain the potency of some unstable allergens (e.g. pollen-related food allergens). Furthermore, data on physicochemical characteristics translating into clinical effects are limited, mainly because most studies are focused on in vitro IgE binding. Clinical data assessing how these parameters affect the development and clinical manifestation of allergies is minimal, with only few reports evaluating the sensitising capacity of modified proteins (addressing different physicochemical properties) in murine allergy models. In vivo testing of modified pure proteins by SPT or DBPCFC is scarce. At this stage, a systematic approach to link the physicochemical properties with clinical plant allergenicity in real-life scenarios is still missing.

Exercise-induced allergic reactions on desensitization to wheat after rush oral immunotherapy

BACKGROUND

The effect of oral immunotherapy (OIT) on wheat allergy is promising in terms of the potential to obtain desensitization; however, the frequency of exercise-induced allergic reactions on desensitization (EIARDs) and the associated risk factors remain to be determined.

METHODS

Twenty-five patients underwent rush OIT for wheat allergy, and 21 achieved the full-dose intake of wheat products (5 g of wheat protein). Exercise-provocation tests were repeatedly performed after the ingestion of a full-dose wheat product. The time-course of the levels of the specific IgEs (sIgE) to wheat extract, total gliadin, deamidated gliadin, recombinant gliadin components (α/β-, γ- and ω-5-), and glutenin (high and low molecular weight) components was analyzed using ImmunoCAP^® , ELISA, or IgE immunoblotting.

RESULTS

Fourteen patients (66.7%) were diagnosed as EIARD+, which remained 5 years after rush OIT in 11 patients (52.4%). There were no differences in the clinical backgrounds of the EIARD+ and EIARD- patients. However, EIARD+ patients showed significantly higher sIgE levels to all gliadin and glutenin components than EIARD- patients before OIT. The sIgE levels to each component decreased equally after 1 and 2 years of OIT. On IgE immunoblotting, sera from all patients reacted to the multiple gluten bands, and some reacted to the water-soluble bands. The intensity of all IgE-reactive bands also became equally lighter after OIT.

CONCLUSIONS

EIARDs were frequently observed and remained for a long period after successful OIT for wheat allergy. None of the specific wheat components were found to contribute to EIARDs.

Disease-Specific Molecular Profiles Highlighted by Radar Graphic Display

BACKGROUND

Management of hundreds of analytes obtained from the molecular multiplex techniques currently available may represent a challenge for clinicians in daily clinical practice.

OBJECTIVES

The aim of the study was to describe a comprehensive and simple approach to assess such complex molecular results, to display relevant disease-specific signatures at a glance, and to facilitate their interpretation.

METHOD

A total of 6,332 consecutive allergic patients, categorized based on clinical symptoms reported at the time of the first visit before IgE testing, were evaluated through ImmunoCAP ISAC112®.

RESULTS AND CONCLUSIONS

The occurrence of bronchial asthma is associated with polcalcin, serum albumin, or lipocalin reactivity. Higher risk of severe reaction to food is linked to tropomyosin or nonspecific lipid transfer protein reactivity (in the absence of plant pathogenesis-related proteins [PR-10] or profilin sensitization). We used radar graphic display to highlight, at a glance, the molecular reactivity profiles associated with relevant disease-specific patterns.

Critical reviews and recent advances of novel non-thermal processing techniques on the modification of food allergens

Nowadays, the increasing prevalence of food allergy has become a public concern related to human health worldwide. Thus, it is imperative and necessary to provide some efficient methods for the management of food allergy. Some conventional processing methods (e.g., boiling and steaming) have been applied in the reduction of food immunoreactivity, while these treatments significantly destroy nutritional components present in food sources. Several studies have shown that novel processing techniques generally have better performance in retaining original characteristics of food and improving the efficiency of eliminating allergens. This review has focused on the recent advances of novel non-thermal processing techniques including high-pressure processing, ultrasound, pulsed light, cold plasma, fermentation, pulsed electric field, enzymatic hydrolysis, and the combination processing of them. Meanwhile, general information on global food allergy prevalence and food allergy pathology are also described. Hopefully, these findings regarding the modifications on the food allergens through various novel food processing techniques can provide an in-depth understanding in the mechanism of food allergy, which in turn possibly provides a strategy to adapt in the reduction of food immunoreactivity for the food industries.

Diagnosis and prevention of food-dependent exercise-induced anaphylaxis

Introduction: Food-dependent, exercise-induced anaphylaxis (FDEIA) is a rare type of anaphylaxis with a growing incidence. Although the precise mechanism by which the patient reacts only in a combination of a culprit food and cofactors are not currently understood, many advances in diagnosis and management have been made since their first description. Areas covered: A literature search in PubMed was performed to review the diagnosis and management of FDEIA. Clinicians should have a high level of suspicion for identification of the culprit foods and the cofactors involved. Component-resolved diagnosis and more accurate provocation tests have revolutionized the diagnosis accuracy. Management is not easy and involves educating the patient to evict the combination of exposure to the culprit foods and the cofactors that elicit anaphylaxis, and how to act and treat if a reaction occurs. Expert opinion: FDEIA is currently misdiagnosed and the authors believe that there are many FDEIA patients labelled as idiopathic anaphylaxis with unnecessary evictions and with a poor quality of life because of the fear of an imminent reaction. Due to recent advances in diagnostic tools and the use of monoclonal antibodies for prophylaxis in persistent cases, FDEIA can have a better prognosis improving the quality of life of the patients and their families.

Intestinal absorption of the wheat allergen gliadin in rats

BACKGROUND

Aspirin enhances food allergy symptoms by increasing absorption of ingested allergens. The objective of this study is to elucidate the role of aspirin in facilitating intestinal absorption of the wheat allergen, gliadin, in rats.

METHODS

Plasma concentrations of gliadin were determined after oral administration by gavage or administration into a closed intestinal loop in rats. We used an in situ intestinal re-circulating perfusion experiment to examine the effect of pepsin on aspirin-facilitated gliadin absorption. Fluorescein isothiocyanate (FITC)-labeled dextran-40 (FD-40) was used as a marker of non-specific absorption. The molecular size of gliadin and its allergenicity in plasma were examined using immunoblot analysis and intradermal reaction tests with Evans blue dye (EBD) extravasation, respectively.

RESULTS

Aspirin increased plasma concentrations of gliadin after oral administration but had no effect in the closed intestinal loop study. An in situ intestinal re-circulating perfusion study showed that FITC-labeled gliadin was absorbed similarly to FD-40. Aspirin increased absorption of both intact and pepsin-digested gliadin, with a more significant effect on absorption of pepsin-treated gliadin. Immunoblotting showed that most gliadin was absorbed in intact form. When the gliadin fraction was extracted from rat plasma after gavage and injected intradermally into gliadin-sensitized rats, EBD extravasation was observed at injection sites in a gliadin dose-dependent manner.

CONCLUSIONS

Aspirin increased the absorption of intact and pepsin-digested gliadin via the paracellular pathway, maintaining their allergenicity. Moreover, the effect of aspirin on gliadin absorption was enhanced by modification and digestion of gliadin in the stomach.

Gluten Free Wheat: Are We There?

Gluten proteins, major determinants of the bread-making quality of wheat, are related to several digestive disorders. Advances in plant genetic breeding have allowed the production of wheat lines with very low gliadin content through the use of RNAi and gene editing technologies. In this review, we carried out a comprehensive study of the application of these cutting-edge technologies towards the development of wheat lines devoid of immunogenic gluten, and their genetic, nutritional and clinical characterization. One line, named E82, showed outstanding nutritional properties, with very low immunogenic gluten and a low stimulation capacity of T-cells from celiac patients. Moreover, a clinical trial with non-celiac wheat sensitivity (NCWS) patients showed that the consumption of bread made with this E82 low gliadin line induced positive changes in the gut microbiota composition.

Food-dependent exercise-induced reactions: lessons from a 15-year retrospective study

BACKGROUND

Food-dependent exercise-induced anaphylaxis (FDEIA) is a life-threatening disorder in which the signs and symptoms of anaphylaxis occur if physical exertion occurs within a few hours of exposure to a food.

AIMS

The aim of this study was to characterise patients diagnosed with FDEIA and related disorders.

METHODS

A retrospective review of electronic clinical data from 2001 to 2016 was carried out. Fifty-seven cases were identified and analysed to establish clinical features, triggering factors and sensitisation patterns.

RESULTS

The number of patients per annum diagnosed with FDEIA or related reactions increased from 1 in 2001 to 18 patients in 2016. Sixty-nine percent reported systemic symptoms consistent with anaphylaxis, and 31% had skin manifestations only. In 33% of cases, the level of triggering exercise was mild. Forty-four percent of patients were sensitised to the omega-5-gliadin fraction of wheat.

CONCLUSIONS

FDEIA is an increasingly recognised serious allergic disease. The clinical diagnosis is supported by targeted sensitisation testing and molecular-based allergy diagnostics. These tools allow implementation of effective dietary and lifestyle modifications that mitigate against future serious reactions. Given the limited access to physicians with specialist allergy training in Ireland, increased awareness of this condition amongst sports medicine specialists and general physicians is required.

Series of 12 cases of wheat-dependent exercise-induced allergy in Aragon, Spain

BACKGROUND AND OBJECTIVES

The ω-5 gliadin (ω5G) is considered the main allergen in wheat-dependent exercise-induced anaphylaxis (WDEIA). These patients experience anaphylactic reactions after consuming wheat and performing physical exercise. The aim of our study was to describe the main characteristics of 12 patients with this diagnosis.

MATERIAL AND METHODS

A descriptive, retrospective study was conducted by reviewing the medical records of 12 patients diagnosed with ω-5G hypersensitivity.

RESULTS

The patients' mean age was 37 years, with 50% men and 50% women. Most of the patients had a history of similar unexamined episodes. The latency period varied from immediate to 150min. The most common symptoms were urticaria (83%), bronchospasms (58%), angio-oedema (42%), hypotension (25%) and gastrointestinal symptoms (16%). The most often involved cofactor was physical exercise. The allergy study was conducted with prick tests and total and specific IgE readings.

CONCLUSIONS

WDEIA is a relatively rare but potentially severe food allergy. Understanding this allergy is therefore important for a correct diagnosis.

Exercise-Induced Anaphylaxis: Literature Review and Recent Updates

PURPOSE OF REVIEW

This paper will review the pathophysiology, diagnosis, and treatment of exercise-induced anaphylaxis and food-dependent, exercise-induced anaphylaxis with an emphasis on novel studies published in the past several years.

RECENT FINDINGS

Exercise-induced anaphylaxis (EIAn) is a clinical syndrome characterized by anaphylaxis during or shortly after physical exertion. The syndrome is broadly grouped into two categories: exercise-induced anaphylaxis and food-dependent, exercise-induced anaphylaxis (FDEIAn). Recent literature indicates that FDEIAn is a primary IgE-mediated food allergy which is augmented by several cofactors. Cofactors such as exercise, NSAIDs, and alcohol increase intestinal permeability and allow increased antigen uptake, thereby causing symptoms. The pathophysiology of EIAn is still under investigation. EIAn and FDEIAn are rare clinical syndromes characterized by symptoms during or shortly after exercise. Despite recent advances in the understanding of EIAn and FDEIAn, the pathophysiology of both conditions is not fully understood.

A Multicenter Evaluation of Diagnosis and Management of Omega-5 Gliadin Allergy (Also Known as Wheat-Dependent Exercise-Induced Anaphylaxis) in 132 Adults

BACKGROUND

Omega-5 gliadin allergy (also known as wheat-dependent exercise-induced anaphylaxis) is a rare allergy to wheat that often presents with intermittent severe anaphylaxis in the context of a cofactor, such as exercise.

OBJECTIVE

To undertake a detailed clinical characterization of the largest cohort of patients with omega-5 gliadin allergy to date.

METHODS

We retrospectively analyzed the demographic characteristics, presentation, investigation, and management of 132 patients presenting with omega-5 gliadin allergy in 4 UK centers.

RESULTS

There were significant delays in diagnosis of 1 to 5 years (40% of patients) and more than 5 years (29% of patients). The commonest cofactors were exercise (80%), alcohol (25%), and nonsteroidal anti-inflammatory drugs (9%). A minority of patients (11%) had no identifiable cofactor. The level of specific IgE to omega-5 gliadin does not predict the severity of allergic reactions. Patients who adhered to a gluten-free diet and those who avoided wheat in combination with exercise achieved the largest reductions in subsequent allergic reactions of 67% and 69%, respectively.

CONCLUSION

Omega-5 gliadin allergy is a rare wheat allergy that presents with severe anaphylaxis. The diagnosis is frequently delayed, and therefore we recommend that all adult patients presenting with anaphylaxis of unclear cause should have omega-5 gliadin specific IgE tested. A gluten-free diet or avoidance of wheat-based meals in combination with exercise (if the cofactor is exercise) helps to significantly decrease the risk of future allergic reactions. However, antihistamines and an epinephrine autoinjector must always be prescribed because one-third of patients continue to have allergic reactions despite dietary advice.

How to manage anaphylaxis in primary care

Anaphylaxis is defined as a severe life-threatening generalized or systemic hypersensitivity reaction characterized by rapidly developing airway and/or circulation problems. It presents with very different combinations of symptoms and apparently mild signs and can progress to fatal anaphylactic shock unpredictably. The difficulty in recognizing anaphylaxis is due, in part, to the variability of diagnostic criteria, which in turn leads to a delay in administration of appropriate treatment, thus increasing the risk of death. The use of validated clinical criteria can facilitate the diagnosis of anaphylaxis. Intramuscular epinephrine (adrenaline) is the medication of choice for the emergency treatment of anaphylaxis. Administration of corticosteroids and H1-antihistamines should not delay the administration of epinephrine, and the management of a patient with anaphylaxis should not end with the acute episode. Long-term management of anaphylaxis should include avoidance of triggers, following confirmation by an allergology study. Etiologic factors suspected in the emergency department often differ from the real causes of anaphylaxis. Evaluation of patients with a history of anaphylaxis should also include an assessment of personal data, such as age and comorbidities, which may increase the risk of severe reactions. Special attention should also be paid to co-factors, as these may easily confound the cause of the anaphylaxis. Patients experiencing anaphylaxis should administer epinephrine as soon as possible. Education (including the use of Internet and social media), written personalized emergency action plans, and self-injectable epinephrine have proven useful for the treatment of further anaphylaxis episodes.

Mechanisms, Cofactors, and Augmenting Factors Involved in Anaphylaxis

Anaphylaxis is an acute and life-threatening systemic reaction. Many triggers have been described, including food, drug, and hymenoptera allergens, which are the most frequently involved. The mechanisms described in anaphylactic reactions are complex and implicate a diversity of pathways. Some of these mechanisms may be key to the development of the anaphylactic reaction, while others may only modify its severity. Although specific IgE, mast cells, and basophils are considered the principal players in anaphylaxis, alternative mechanisms have been proposed in non-IgE anaphylactic reactions. Neutrophils, macrophages, as well as basophils, have been involved, as have IgG-dependent, complement and contact system activation. A range of cationic substances can induce antibody-independent mast cells activation through MRGPRX2 receptor. Cofactors and augmenting factors may explain why, in some patients, food allergen exposure can cause anaphylaxis, while in other clinical scenario it can be tolerated or elicits a mild reaction. With the influence of these factors, food allergic reactions may be induced at lower doses of allergen and/or become more severe. Exercise, alcohol, estrogens, and some drugs such as Non-steroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, β-blockers, and lipid-lowering drugs are the main factors described, though their mechanisms and signaling pathways are poorly understood.

A two-step enzymatic modification method to reduce immuno-reactivity of milk proteins

A two-step enzymatic approach to reduce immuno-reactivity of whey protein isolate and casein has been studied. The method involves partial hydrolysis of proteins with proteases, followed by repolymerization with microbial transglutaminase. Whey protein isolate partially hydrolyzed with chymotrypsin, trypsin, or thermolysin retained about 80%, 30%, and 20% of the original immuno-reactivity, respectively. Upon repolymerization the immuno-reactivity decreased to 45%, 35%, and 5%, respectively. The immuno-reactivity of hydrolyzed and repolymerized casein was negligible compared to native casein. The repolymerized products were partially resistant to in vitro digestion. Peptides released during digestion of repolymerized thermolysin-whey protein hydrolysate had less than 5% immuno-reactivity, whereas those of whey protein control exhibited a sinusoidal immuno-reactivity ranging from 5 to 20%. Peptides released during digestion of repolymerized thermolysin-casein hydrolysates had no immuno-reactivity. These results indicated that it is possible to produce hypoallergenic milk protein products using the two-step enzymatic modification method involving thermolysin and transglutaminase.

Wheat-dependent exercise-induced anaphylaxis

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a rare, but potentially severe food allergy exclusively occurring when wheat ingestion is accompanied by augmenting cofactors. It is clinically characterized by anaphylactic reactions ranging from urticaria and angioedema to dyspnoea, hypotension, collapse, and shock. WDEIA usually develops after ingestion of wheat products followed by physical exercise. Other cofactors are acetylsalicylic acid and other non-steroidal anti-inflammatory drugs, alcohol, and infections. The precise mechanisms of WDEIA remain unclear; exercise and other cofactors might increase gastrointestinal allergen permeability and osmolality, redistribute blood flow, or lower the threshold for IgE-mediated mast cell degranulation. Among wheat proteins, ω5-gliadin and high-molecular-weight glutenin subunits have been reported to be the major allergens. In some patients, WDEIA has been discussed to be caused by epicutaneous sensitization with hydrolysed wheat gluten included in cosmetics. Diagnosis is made based on the patient's history in combination with allergy skin testing, determination of wheat-specific IgE serum antibodies, basophil activation test, histamine release test, and/or exercise challenge test. Acute treatment includes application of adrenaline or antihistamines. The most reliable prophylaxis of WDEIA is a gluten-free diet. In less severe cases, a strict limitation of wheat ingestion before exercise and avoidance of other cofactors may be sufficient.

Exercise-induced bronchoconstriction update-2016

The first practice parameter on exercise-induced bronchoconstriction (EIB) was published in 2010. This updated practice parameter was prepared 5 years later. In the ensuing years, there has been increased understanding of the pathogenesis of EIB and improved diagnosis of this disorder by using objective testing. At the time of this publication, observations included the following: dry powder mannitol for inhalation as a bronchial provocation test is FDA approved however not currently available in the United States; if baseline pulmonary function test results are normal to near normal (before and after bronchodilator) in a person with suspected EIB, then further testing should be performed by using standardized exercise challenge or eucapnic voluntary hyperpnea (EVH); and the efficacy of nonpharmaceutical interventions (omega-3 fatty acids) has been challenged. The workgroup preparing this practice parameter updated contemporary practice guidelines based on a current systematic literature review. The group obtained supplementary literature and consensus expert opinions when the published literature was insufficient. A search of the medical literature on PubMed was conducted, and search terms included pathogenesis, diagnosis, differential diagnosis, and therapy (both pharmaceutical and nonpharmaceutical) of exercise-induced bronchoconstriction or exercise-induced asthma (which is no longer a preferred term); asthma; and exercise and asthma. References assessed as relevant to the topic were evaluated to search for additional relevant references. Published clinical studies were appraised by category of evidence and used to document the strength of the recommendation. The parameter was then evaluated by Joint Task Force reviewers and then by reviewers assigned by the parent organizations, as well as the general membership. Based on this process, the parameter can be characterized as an evidence- and consensus-based document.

Pathophysiological mechanisms of exercise-induced anaphylaxis: an EAACI position statement

This document is the result of a consensus on the mechanisms of exercise-induced anaphylaxis (EIAn), an unpredictable and potentially fatal syndrome. A multidisciplinary panel of experts including exercise physiologists, allergists, lung physicians, paediatricians and a biostatistician reached the given consensus. Exercise-induced anaphylaxis (EIAn) describes a rare and potentially fatal syndrome in which anaphylaxis occurs in conjunction with exercise. The pathophysiological mechanisms underlying EIAn have not yet been elucidated although a number of hypotheses have been proposed. This review evaluates the validity of each of the popular theories in relation to exercise physiology and immunology. On the basis of this evidence, it is concluded that proposed mechanisms lack validity, and it is recommended that a global research network is developed with a common approach to the diagnosis and treatment of EIAn in order to gain sufficient power for scientific evaluation.

Food dependant exercise induced anaphylaxis a retrospective study from 2 allergy clinics in Colombo, Sri Lanka

The aetiology of anaphylaxis ranges from food, insect venom, drugs and various chemicals. Some individuals do not develop anaphylaxis with the offending agent unless ingestion is related temporally to physical exertion, namely food dependent exercise induced anaphylaxis (FDEIA). The foods implicated are wheat, soya, peanut, milk and sea food. A retrospective study on patients with FDEIA from two Allergy clinics in Sri Lanka from 2011 to 2015 is reported. Patients were selected who fulfilled the following criteria: clinical diagnosis of anaphylaxis according to the World Allergy Organization (WAO) criteria, where the onset of symptoms was during exertion, within 4 h of ingesting a food, the ability to eat the implicated food independent of exercise, or exercise safely, if the food was not ingested in the preceding 4 h and an in vitro (ImmunoCap serum IgE to the food) or in vivo (skin prick test) test indicating evidence of sensitivity to the food. There were 19 patients (12 males: 7 females). The ages ranged from 9 to 45 (mean 22.9, median 19 years). Eight patients (42.1%) were in the 9-16 age group. Those below 16 years had a male:female ratio of 3:5, while for those above 16 years it was 9:2. Wheat was the only food implicated in FDEIA in all patients and was confirmed by skin prick testing, or by ImmunoCap specific IgE to wheat or ω - 5 gliadin. All patients had urticaria, while 5/19 (26.3%) had angioedema of the lips. Fifteen patients (78.9%) had shortness of breath or wheezing, while 8 (42.1%) had lost consciousness. Nine patients (47. 3%) had hypotension. Fourteen (73.6%) of our patients had severe reactions, with loss of consciousness or hypotension, while 5 (26.3%) had symptoms related to the gastrointestinal tract. One patient developed anaphylaxis on two occasions following inhalation of ganja, a local cannabis derivative along with the ingestion of wheat and exertion. Wheat is the main food implicated in FDEIA in Sri Lanka. A local cannabis derivative, ganja has been implicated as a cofactor for the first time.

Anaphylaxis attributed to exercise: considerations for sports medicine specialists

Anaphylaxis is an unanticipated, acute, and sometimes life-threatening systemic reaction with variable clinical presentations that is typically mediated by immunoglobulin E and causes degranulation of mast cells and basophils. The onset of symptoms can occur within minutes or hours after exposure to a known or suspected trigger, and reactions sometimes progress very rapidly, which can lead to death. One trigger of anaphylaxis in younger adults is moderately intense physical exercise, which has been termed exercise-induced anaphylaxis (EIA). Although rare, EIA should be recognized as a distinct and potentially life-threatening form of physical allergy, and is often undetected or inadequately treated. The ingestion of specific foods, including seafood, tree nuts, and wheat, or a nonspecific meal consisting of multiple food components shortly before or after physical exertion, is sometimes, but not always, the principal precipitant of EIA. This article briefly explores the current hypotheses on the role of immunoglobulin E, response mediators, and physiologic changes that bring on EIA, and discusses the current recommendations for diagnosis, including allergen challenge and laboratory testing, emergency care, and long-term prevention and patient follow-up. Accurate diagnosis of EIA is critical to providing lifesaving therapy and care plans to patients at risk. With respect to the medical management of EIA, mainstay therapy with epinephrine is described. For those with a known history of EIA, a comprehensive anaphylaxis action plan is central to successful patient management. Furthermore, patient education is necessary to heighten awareness of the signs and symptoms of EIA and appropriate strategies for allergen avoidance and self-management of anaphylactic episodes with self-injectable epinephrine.

Lessons about food anaphylaxis

Exercise-induced anaphylaxis (EIA) and its subtype food-dependent (FD)-EIA are uncommon and easily missed forms of physical allergy. The latter is triggered by exercise following the ingestion of specific food products. Treatment is identical to that for IgE-mediated allergic reactions. The disease is potentially fatal. In this case, 30-year-old woman was seen in the allergy clinic at the request of her general practitioner. She reported an episode when she had gone to a local park to exercise after dinner. Shortly thereafter, she collapsed with rash, lip swelling, and breathing difficulties. Upon admission to hospital, she was found to be hypotensive and required fluid resuscitation, systemic corticosteroids and adrenaline. She made a full and uneventful recovery. On the basis of the clinical story and specific allergy markers, her presentation was attributed to FD-EIA.

Factors augmenting allergic reactions

Elicitors of anaphylactic reactions are any sources of protein with allergenic capacity. However, not all allergic reactions end up in the most severe form of anaphylaxis. Augmenting factors may explain why certain conditions lead to anaphylaxis. Augmenting factors may exhibit three effects: lowering the threshold, increasing the severity, and reversing acquired clinical tolerance. Common augmenting factors are physical exercise, menstruation, NSAIDs, alcohol, body temperature, acute infections, and antacids. Therapeutic options may address causative, preventive, pragmatic, or symptomatic considerations: avoid the eliciting food, take an antihistamine before any situation with a possible risk of augmentation, separate food and sport (at least for 2 h), and carry an adrenaline autoinjector at all times. Individual patterns include summation effects and specific patterns. In conclusion, in the case of a suggestive history but a negative oral challenge, one should consider the possible involvement of augmenting factors; after anaphylactic reactions, always ask for possible augmentation and other risk factors during the recent past; if augmentation is suspected, oral food challenges should be performed in combination with augmenting factors; and in the future, standardized challenge protocols including augmenting factors should be established.

A Severe Case of Wheat-Dependent Exercise-Induced Anaphylaxis in Adulthood

Food-dependent exercise-induced anaphylaxis (FDEIA), is a severe form of allergy for which the ingestion of a specific food, usually before physical exercise induces symptoms of anaphylaxis. Patients typically have IgE antibodies to the food that triggers the reactions; however, the symptoms appear only if the co-factors act together. The most common reported cause of these reactions seems to be wheat. In some cases FDEIA is displayed even when the food is eaten immediately after exercise, showing that in FDEIA, not the sequence but rather the coincidence of triggering factors use, is of crucial importance. The risk to develop anaphylaxis in these patients depends on the presence and, in some cases, on the amount of cofactors of anaphylaxis. There are lots of evidences about the role of NSAIDs as cofactors of anaphylaxis.

Transglutaminase II/microRNA-218/-181a loop regulates positive feedback relationship between allergic inflammation and tumor metastasis

The molecular mechanism of transglutaminase II (TGaseII)-mediated allergic inflammation remains largely unknown. TGaseII, induced by antigen stimulation, showed an interaction and co-localization with FcϵRI. TGaseII was necessary for in vivo allergic inflammation, such as triphasic cutaneous reaction, passive cutaneous anaphylaxis, and passive systemic anaphylaxis. TGaseII was necessary for the enhanced metastatic potential of B16F1 melanoma cells by passive systemic anaphylaxis. TGaseII was shown to be a secreted protein. Recombinant TGaseII protein increased the histamine release and β-hexosaminidase activity, and enhanced the metastatic potential of B16F1 mouse melanoma cells. Recombinant TGaseII protein induced the activation of EGF receptor and an interaction between EGF receptor and FcϵRI. Recombinant TGaseII protein displayed angiogenic potential accompanied by allergic inflammation. R2 peptide, an inhibitor of TGaseII, exerted negative effects on in vitro and in vivo allergic inflammation by regulating the expression of TGaseII and FcϵRI signaling. MicroRNA (miR)-218 and miR-181a, decreased during allergic inflammation, were predicted as negative regulators of TGaseII by microRNA array and TargetScan analysis. miR-218 and miR-181a formed a negative feedback loop with TGaseII and regulated the in vitro and in vivo allergic inflammation. TGaseII was necessary for the interaction between mast cells and macrophages during allergic inflammation. Mast cells and macrophages, activated during allergic inflammation, were responsible for the enhanced metastatic potential of tumor cells that are accompanied by allergic inflammation. In conclusion, the TGaseII/miR-218/-181a feedback loop can be employed for the development of anti-allergy therapeutics.

Evaluation of reduced allergenicity of deamidated gliadin in a mouse model of wheat-gliadin allergy using an antibody prepared by a peptide containing three epitopes

Gliadin is the principal allergen of wheat-dependent exercise-induced anaphylaxis (WDEIA). The primary structure of IgE-binding epitopes in wheat gliadin includes tandem sequencing sites of glutamine residues. Therefore, deamidation would be an effective approach to reduce the allergenicity of wheat proteins. In our previous study, we deamidated wheat gliadin without causing peptide-bond hydrolysis or polymerization by use of carboxylated cation-exchange resins, and we found that the deamidated gliadin scarcely reacted with the sera of patients radioallergosorbent test (RAST)-positive to wheat. In this study, we examined the allergenicity of deamidated gliadin in a mouse model of wheat-gliadin allergy. Oral administration of deamidated gliadin to gliadin-sensitized mice suppressed enhancement in intestinal permeability, serum allergen level, serum allergen-specific IgE level, mast-cell-surface expression of FcεRI, and serum and intestinal histamine levels. Our results indicate that gliadin deamidated with no peptide-bond hydrolysis by cation-exchange resins has low allergenicity even under in vivo conditions.

A dangerous exercise lessons from food-dependent anaphylaxis for the physician

Exercise-induced anaphylaxis (EIA) and its subtype, food dependent exercise-induced anaphylaxis are uncommon and therefore underdiagnosed forms of physical allergy. Triggers include various degrees of exercise in combination with ingestion of specific food products. Treatment remains identical to that of IgE-mediated allergic reactions. The presentation is commonly underdiagnosed and caries significant fatality risk, and this case should raise the awareness of the attending physician.