Clinical characteristics of soybean allergy in Europe: a double-blind, placebo-controlled food challenge study

Challenges and health outcomes of the exposure to soybean dust in the harbor neighborhood of Karachi, Pakistan: a wake-up call

BACKGROUND

Chemical disasters are common worldwide and result from technological failure, war, and terrorism activities. Pakistan imports huge quantities of hazardous chemicals to meet its industrial and energy needs. Hence there is a risk of chemical disaster at the ports, during transportation of such material and processing in the chemical industry. This study aimed to review the challenges and health outcomes of cases of soybean dust exposure in Kemari district (harbor neighborhood) of Karachi, Pakistan.

METHODS

A cross-sectional survey was conducted with all the affected people from a chemical incident of soybean dust which was reported in the Keamari district of Karachi, Pakistan. Included patients ≥ 18 years who visited the two major tertiary care hospitals of Karachi, Pakistan after the incident between February 17 to 23, 2020. A total of 574 patients were brought to these two major tertiary care hospitals. We collected data on basic demographics, event details, and major signs and symptoms of the affected individuals. Calculated frequencies and percentages for categorical variables. Mean ± standard deviation (SD) was calculated for continuous variables.

RESULTS

The mean ± (SD) age of the victims were 32 (13.5) years. Of the 574 patients, majority of the patients (n = 319, 56%) were males. In 28 cases (41%), the onset of symptoms occurred at home, in 27 cases (39%) the onset of symptoms started in the workplace and the remaining cases (n = 14, 20%) experienced the first symptoms while roaming around the roadside. The most common reported co-morbidity was a history of asthma (56%), followed by diabetes mellitus (22%). The most common clinical manifestation was shortness of breath, reported in 94% of the cases, followed by neurological symptoms such as drowsiness, unconsciousness, or seizures experienced by 10% of the victims. A total of 9 deaths (1.5%) were recorded.

CONCLUSION

A multi-sectoral systematic approach is also required to address these incidents comprehensively including the trained and equipped pre-hospital system, integrated emergency medical response, and community-wide emergency response system.

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.

Effects of Lactobacillus on the Differentiation of Intestinal Mucosa Immune Cells and the Composition of Gut Microbiota in Soybean-Sensitized Mice

In the early stage of this study, three strains of Lactobacillus with anti-soybean allergy potential were screened: Lactobacillus acidophilus CICC 6081, Lactobacillus delbrueckii subsp. Bulgaricus CICC 6103 and Lactobacillus plantarum subsp. Plantarum CICC 20988. The aim of this study was to analyze the desensitization effect of three strains of Lactobacillus administered by gavage to soybean-allergic mice through the differentiation of immune cells in intestinal lymph nodes and the changes to gut microbiota. The results showed that the three strains of Lactobacillus could stimulate the proliferation of dendritic cells (DCs) and regulate the balance of Th1/Th2 differentiation in the MLNs and PPs of soybean-allergic mice. Furthermore, the Th17/Tregs cell-differentiation ratio in the MLNs of the Lactobacillus-treated mice was significantly lower than that of the allergic mice (p < 0.05). Compared to the control group, the Shannon, Sobs and Ace indexes of intestinal microbiota in the allergic mice were significantly increased (p < 0.05), and the proportion of Clostridiales was significantly higher (p < 0.05), which was reversed by Lactobacillus gavage. In conclusion, the three strains of Lactobacillus can inhibit the intestinal mucosal immune response and regulate gut microbiota balance in soybean-allergic mice.

BSACI guideline for the diagnosis and management of pollen food syndrome in the UK

Pollen food syndrome (PFS) is a highly prevalent food allergy affecting pollen-sensitized children and adults. Sufferers experience allergic symptoms when consuming raw plant foods, due to the homology between the pollen allergens and unstable proteins in these foods. The triggers involved can vary depending on the pollen sensitization, which in turn is affected by geographical location. The British Society of Allergy and Clinical Immunology (BSACI) Standards of Care Committee (SOCC) identified a need to develop a guideline for the diagnosis and management of PFS in the United Kingdom (UK). Guidelines produced by the BSACI use either the GRADE or SIGN methodology; due to a lack of high-quality evidence these recommendations were formulated using the SIGN guidelines, which is acknowledged to be less robust than the GRADE approach. The correct diagnosis of PFS ensures the avoidance of a misdiagnosis of a primary peanut or tree nut allergy or confusion with another plant food allergy to non-specific lipid transfer proteins. The characteristic foods involved, and rapid-onset oropharyngeal symptoms, mean PFS can often be diagnosed from the clinical history alone. However, reactions involving tree nuts, peanuts and soya milk or severe/atypical reactions to fruits and vegetables may require additional diagnostic tests. Management is through the exclusion of known trigger foods, which may appear to be simple, but is highly problematic if coupled with a pre-existing food allergy or for individuals following a vegetarian/vegan diet. Immunotherapy to pollens is not an effective treatment for PFS, and although oral or sublingual immunotherapy to foods seems more promising, large, controlled studies are needed. The typically mild symptoms of PFS can lead to an erroneous perception that this condition is always easily managed, but severe reactions can occur, and anxiety about the onset of symptoms to new foods can have a profound effect on quality of life.

Utility of the Basophil Activation Test Using Gly m 4, Gly m 5 and Gly m 6 Molecular Allergens for Characterizing Anaphylactic Reactions to Soy

There are two major clinically described forms of IgE-dependent soy allergy: (i) a primary dietary form, linked to sensitization against soy storage proteins Gly m 5 and Glym 6, and (ii) a form included in birch-soy syndromes linked to Gly m 4, a PR-10-like allergen. This second form sometimes causes severe systemic reactions, even anaphylaxis, especially on consuming certain forms of soy such as soymilks or smoothies. Skin prick tests and specific IgE assays against soy whole extracts lack sensitivity. Assays of anti-Gly m 4, Gly m 5 and Gly m 6 specific IgEs have been developed to overcome this obstacle, but they unfortunately lack specificity, especially for anti-Gly m 4. We hypothesized that the basophil activation test (BAT) using molecular soy allergens Gly m 4, Gly m 5 and Gly m 6 would both remedy the lack of sensitivity of other tests and offer, through its mechanistic contribution, greater specificity than the assay of anti-Gly m 4 specific IgEs. This would enable the two types of soy allergy to be separately identified. In a characteristic clinical example of PR-10-induced anaphylactic reaction after consuming soymilk, we report preliminary results of Gly m 4-exclusive positivity of BAT supporting our hypothesis. It will be necessary to confirm these results on more patients in subsequent studies, and to specify the place of the BAT in an overall diagnostic strategy. Meanwhile, soy BAT using molecular allergens is a promising diagnostic tool for soy allergy and probably also for follow-up in specific immunotherapies.

Characterization of the Reduced IgE Binding Capacity in Boiled and Autoclaved Soybeans through Proteomic Approaches

The study investigated the changes in IgE binding capacity, protein profiles and peptide compositions after soybeans were boiled and autoclaved. The results of ELISA showed that the IgE binding capacity of soybean was reduced by 69.3% and 88.9% after boiling and autoclaving, respectively. Above 43 and 10 kDa proteins disappeared in boiled and autoclaved soybeans from SDS-PAGE, respectively. A Venn diagram and heat map showed that there was no change in allergen types and a reduction in allergen contents in the boiled and autoclaved soybeans. The changes in peptide compositions were also observed in the boiled and autoclaved soybeans through Venn diagram, PCA and heat map. LC/MS-MS and peptide mapping analysis demonstrated that boiling and autoclaving masked many epitopes in Gly m 4 and Gly m 5, such as ALVTDADNVIPK, SVENVEGNGGPGTIKK and KITFLEDGETK of Gly m 4 and VEKEECEEGEIPRPRPRPQHPER of Gly m 5, resulting in a reduction of IgE binding capacity in the extracted proteins. By contrast, the exposure of many epitopes in Gly m 6 was observed in boiled and autoclaved soybeans, which might be mainly responsible for the existing IgE binding capacity in the treated soybean proteins. Interestingly, the IgE binding capacity of soybeans showed a positive correlation with the total contents and number of peptides in Gly m 4-Gly m 6.

Peanut Can Be Used as a Reference Allergen for Hazard Characterization in Food Allergen Risk Management: A Rapid Evidence Assessment and Meta-Analysis

Regional and national legislation mandates the disclosure of “priority” allergens when present as an ingredient in foods, but this does not extend to the unintended presence of allergens due to shared production facilities. This has resulted in a proliferation of precautionary allergen (“may contain”) labels (PAL) that are frequently ignored by food-allergic consumers. Attempts have been made to improve allergen risk management to better inform the use of PAL, but a lack of consensus has led to variety of regulatory approaches and nonuniformity in the use of PAL by food businesses. One potential solution would be to establish internationally agreed “reference doses,” below which no PAL would be needed. However, if reference doses are to be used to inform the need for PAL, then it is essential to characterize the hazard associated with these low-level exposures. For peanut, there are now published data relating to over 3000 double-blind, placebo-controlled challenges in allergic individuals, but a similar level of evidence is lacking for other priority allergens. We present the results of a rapid evidence assessment and meta-analysis for the risk of anaphylaxis to a low-level allergen exposure for priority allergens. On the basis of this analysis, we propose that peanut can and should be considered an exemplar allergen for the hazard characterization at a low-level allergen exposure.

Purification of soybean cupins and comparison of IgE binding with peanut allergens in a population of allergic subjects

Identification, purification and characterization of allergens is crucial to the understanding of IgE-mediated disease. Immunologic and structural studies with purified allergens is essential for understanding relative immunogenicity and cross-reactivity. In this work, the complex soybean 7S vicilins (Gly m 5) with three subunits and 11S legumins (Gly m 6) with five subunits were purified and characterized along with purified peanut allergens (Ara h 1, 2, 3, and 6) by label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS). Individual subjects plasma IgE binding was tested from subjects allergic to soybeans and or peanuts by immunoblotting, ImmunoCAP™ and ISAC™ ImmunoCAP chip, comparing these soybean proteins with those of purified peanut allergens; vicilin (Ara h 1), 2S albumin (Ara h 2 and Ara h 6) and 11S globulin (Ara h 3). Results show differences between methods and subjects demonstrating the complexity of finding answers to questions of cross-reactivity.

LAMP-LFD Based on Isothermal Amplification of Multicopy Gene ORF160b: Applicability for Highly Sensitive Low-Tech Screening of Allergenic Soybean (Glycine max) in Food

Soybean (Glycine max) allergy can be life threatening. A lack of causative immunotherapy of soybean allergy makes soybean avoidance indispensable. Detection methods are essential to verify allergen labeling and unintentional allergen cross contact during food manufacture. Here, we aimed at evaluating our previously described primers for loop-mediated isothermal amplification (LAMP) of multicopy gene ORF160b, combined with a lateral flow dipstick (LFD)-like detection, for their performance of soybean detection in complex food matrices. The results were compared with those obtained using quantitative real-time Polymerase Chain Reaction (qPCR) as the current standard of DNA-based allergen detection, and antibody-based commercial lateral flow device (LFD) as the current reference of protein-based rapid allergen detection. LAMP-LFD allowed unequivocal and reproducible detection of 10 mg/kg soybean incurred in three representative matrices (boiled sausage, chocolate, instant tomato soup), while clear visibility of positive test lines of two commercial LFD tests was between 10 and 10² mg/kg and depending on the matrix. Sensitivity of soybean detection in incurred food matrices, commercial retail samples, as well as various processed soybean products was comparable between LAMP-LFD and qPCR. The DNA-based LAMP-LFD proved to be a simple and low-technology soybean detection tool, showing sensitivity and specificity that is comparable or superior to the investigated commercial protein-based LFD.

Food-dependent exercise-induced anaphylaxis to soybean: Gly m 5 and Gly m 6 as causative allergen components

Food-dependent exercise-induced anaphylaxis (FDEIA) is a life-threatening but relatively rare disorder which occurs mainly in older children and young adults and manifests with symptoms of anaphylaxis upon exercise following ingestion of certain kinds of food. We herewith report 3 cases of soybean-induced FDEIA. We also highlight 2 types of soybean-induced FDEIA, one caused by storage protein components Gly m 5 and Gly m 6 and the other caused by pollen-related allergen components.

Natural ingredients in cosmetic products-A suggestion for a screening series for skin allergy

BACKGROUND

Naturally derived cosmetic product ingredients of both plant and animal origin are being included increasingly in product formulations in order to cater to consumer preferences. They may be an overlooked cause of reactions to cosmetic products in some patients with dermatitis.

OBJECTIVES

To identify naturally derived cosmetic product ingredients with allergenic potential (type I and type IV) and propose a cosmetic screening test series.

METHODS

The study was conducted in two steps. The first step was a market survey using a nonprofit application helping consumers avoid problematic substances in cosmetic products. The application contained 10 067 cosmetic products that were label checked for naturally derived cosmetic product ingredients. The second step was a literature search to examine how frequently the naturally derived ingredients were described and related to allergic reactions in cosmetics or other topically administered products.

RESULTS

We identified 121 different naturally derived cosmetic product ingredients that were included in at least 30 cosmetic products. In total, 22 ingredients were selected for a screening test series.

CONCLUSIONS

We propose a supplemental patch test and a prick test screening series with naturally derived cosmetic product ingredients for patients with skin reactions to cosmetic products, aiming to identify a cause in more patients than is currently possible.

The Development of Highly Specific and Sensitive Primers for the Detection of Potentially Allergenic Soybean (Glycine max) Using Loop-Mediated Isothermal Amplification Combined with Lateral Flow Dipstick (LAMP-LFD)

The soybean (Glycine max) has been recognized as a frequent elicitor of food allergy worldwide. A lack of causative immunotherapy of soybean allergy makes soybean avoidance essential. Therefore, sensitive and specific methods for soybean detection are needed to allow for soybean verification in foods. Loop-mediated isothermal amplification (LAMP) represents a rapid and simple DNA-based detection method principally suitable for field-like applications or on-site analytical screening for allergens during the manufacturing of foods. This work describes the systematic development and selection of suitable LAMP primers based on soybean multicopy genes. The chemistry applied allows for a versatile detection of amplified DNA, using either gel electrophoresis, fluorescence recording, or a simple Lateral Flow Dipstick (LFD). LAMP based on the ORF160b gene was highly specific for the soybean and may allow for a detection level equivalent to approximately 10 mg soy per kg food. Various soybean cultivars were detectable at a comparable level of sensitivity. LAMP combined with LFD-like detection facilitates a simple, highly specific and sensitive detection of the soybean without the need for expensive analytical equipment. In contrast to the majority of antibody-based methods for soybean detection, all identified primer sequences and optimized protocols are disclosed and broadly available to the community.

IgE allergy diagnostics and other relevant tests in allergy, a World Allergy Organization position paper

Currently, testing for immunoglobulin E (IgE) sensitization is the cornerstone of diagnostic evaluation in suspected allergic conditions. This review provides a thorough and updated critical appraisal of the most frequently used diagnostic tests, both in vivo and in vitro. It discusses skin tests, challenges, and serological and cellular in vitro tests, and provides an overview of indications, advantages and disadvantages of each in conditions such as respiratory, food, venom, drug, and occupational allergy. Skin prick testing remains the first line approach in most instances; the added value of serum specific IgE to whole allergen extracts or components, as well as the role of basophil activation tests, is evaluated. Unproven, non-validated, diagnostic tests are also discussed. Throughout the review, the reader must bear in mind the relevance of differentiating between sensitization and allergy; the latter entails not only allergic sensitization, but also clinically relevant symptoms triggered by the culprit allergen.

The hidden 'plant side' of insect novel foods: A DNA-based assessment

In the context of novel foods, a category for which the market demand is increasing worldwide, the consumption of edible insects and related insect-based products is expected to grow in the next years. Insects represent an important source of energy for the human diet but there is a lack of scientific knowledge about their processing to ensure safe food items to the consumer. In this study we adopted a combined DNA-based approach to verify the identity of the declared species in five categories of commercial insect-based products (mt COI DNA barcoding) and to characterize plant declared ingredients or contaminants (nu ITS2 DNA metabarcoding) with particular attention to putative elements of allergenic concern belonging, for example to the insect rearing substrate. Moreover, the same approach has been used to assess its sensitivity to cases of contamination and counterfeits to insect flour with low cost (and potentially allergenic) vegetable flours like wheat and soybean. Results show the success of insect DNA barcoding authentication even for highly processed products. Furthermore, the DNA metabarcoding analysis revealed a high efficacy as a screening method to identify both plant ingredients and vegetal traces belonging to insect farming or possible adulteration events, also acting as an early warning strategy for the occurrence of allergens of human concern. This approach could support the development of new risk assessment procedures for novel foods by regulatory authorities to ensure their quality, safety, and acceptance which will become more required in order to face the challenge of feeding the world population in the next decades.

Gly m 5/Gly m 8 fusion component as a potential novel candidate molecule for diagnosing soya bean allergy in Japanese children

BACKGROUND

Soya bean is a major food allergen in children. Component-resolved diagnostics has improved the accuracy of diagnosing immunoglobulin E (IgE)-mediated food allergies.

OBJECTIVE

We aimed to develop a novel component for the diagnosis of soya bean allergy using recombinant technology.

METHODS

Japanese paediatric patients with suspected soya bean allergy (n = 91) were included, and symptomatic (n = 40) and asymptomatic (n = 51) cases were divided through oral food challenge testing. Specific IgE (sIgE) antibodies to each recombinant allergen component were analysed by enzyme-linked immunosorbent assay, and the diagnostic performances of the components were assessed by area under the receiver operating characteristic curves (AUC).

RESULTS

Among the recombinant components, sIgE antibody levels to Gly m 8 showed the highest AUC (0.706). A combination of Gly m 8 and α' subunit of Gly m 5, improved the diagnostic performance of the single components. Moreover, the N-terminal extension region of α' subunit of Gly m 5, which has low cross-reactivity among the vicilins, showed higher diagnostic performance (AUC 0.695) than the full-length α' subunit of Gly m 5 (AUC 0.613). Based on these findings, we developed a fusion protein of Gly m 8 plus the extension region of α' subunit of Gly m 5; this fusion protein was very efficient for diagnosing soya bean allergy (AUC 0.801).

CONCLUSION

A fusion protein of Gly m 8 and the extension region of α' subunit of Gly m 5 could potentially diagnose soya bean allergy in paediatric patients. Fusion proteins may be useful for producing novel allergen components with improved diagnostic value.

Cross-Reactive Aeroallergens: Which Need to Cross Our Mind in Food Allergy Diagnosis?

Secondary food allergies due to cross-reactivity between inhalant and food allergens are a significant and increasing global health issue. Cross-reactive food allergies predominantly involve plant-derived foods resulting from a prior sensitization to cross-reactive components present in pollen (grass, tree, weeds) and natural rubber latex. Also, primary sensitization to allergens present in fungi, insects, and both nonmammalian and mammalian meat might induce cross-reactive food allergic syndromes. Correct diagnosis of these associated food allergies is not always straightforward and can pose a difficult challenge. As a matter of fact, cross-reactive allergens might hamper food allergy diagnosis, as they can cause clinically irrelevant positive tests to cross-reacting foods that are safely consumed. This review summarizes the most relevant cross-reactivity syndromes between inhalant and food allergens. Particular focus is paid to the potential and limitations of confirmatory testing such as skin testing, specific IgE assays, molecular diagnosis, and basophil activation test.

Birch pollen-related foods can cause late eczematous reactions in patients with atopic dermatitis

BACKGROUND

Previous studies have indicated that in patients with atopic dermatitis (AD) and birch pollen allergy pollen-related foods are able to cause late eczematous response. However, the relevance of AD worsening by ingestion of birch pollen-related foods is still a matter of debate.

OBJECTIVE

The purpose of this retrospective study was to determine how frequently birch pollen-related foods induce a deterioration of eczema. Additionally, the diagnostic value of specific IgE (sIgE) determination was evaluated.

METHODS

A total of 182 children and adults with AD and suspected birch pollen-related food allergy underwent 261 double-blind placebo-controlled food challenges (DBPCFC). Total and sIgE levels were determined prior to DBPCFC.

RESULTS

Sixty-five patients developed allergic reactions (responders) upon DBPCFC with birch pollen-related foods (n = 103 DBPCFC). Of these, 32 patients exhibited significant deterioration of AD defined as a median increase of 15.4 severity scoring of atopic dermatitis index points (95% CI 12.4-16.3) from baseline making up 37% of all positive reactions. Responders showed significantly higher sIgE levels to birch pollen and apple as well as a higher prevalence of allergic rhinoconjunctivitis compared to nonresponders (P < .05). However, patients with late eczematous response could not be differentiated from those with isolated immediate-type reactions by sIgE levels.

CONCLUSION

In a subpopulation of patients with AD and birch pollen sensitization, related foods should be considered as a trigger for an aggravation of eczema. As sufficient markers for prediction of late eczematous reactions are still lacking, DBPCFC cannot be replaced in diagnosis of birch pollen-related foods in patients with AD.

CLINICAL IMPLICATIONS

In patients with AD and birch pollen allergy, birch pollen-related foods should be considered as a provocation factor for an aggravation of disease signs and symptoms.

Degradation of major allergens and allergenicity reduction of soybean meal through solid-state fermentation with microorganisms

In this study, we determined whether solid-state fermentation could degrade major allergens and reduce potential allergenicity of soybean meal (SBM). Solid-state fermentation was realized through a mixture of Lactobacillus casei, yeast, and Bacillus subtilis. High-performance liquid chromatography, size exclusion-high-performance liquid chromatography, and capillary liquid chromatography/tandem mass spectrometry coupled with electrospray ionization were used to examine the total amino acids and molecular weight distribution of the fermented soybean meal (FSBM). In addition, the potential allergenicity of FSBM was assessed by conducting in vitro competitive inhibition ELISA and oral sensitization and challenge of a BALB/c mice model. The results indicated that the total amino acid content increased and soy protein was degraded into polypeptides with low molecular weights that were derived from the hydrolysis of the allergen sequences N232-D383, G253-I265, E169-S215, G68-G98, A365-I375, and V153-A167. Moreover, the FSBM group exhibited a lower in vitro immunoglobulin E (IgE)-binding capacity than the SBM group. The BALB/c model indicated that the FSBM group manifested milder damage to the intestine, lower mMCP-1 and IgE levels, and higher IFN-γ levels as compared to the SBM group. These findings suggested that the potential allergenicity of SBM was reduced by the solid-state fermentation induced by the mixture of Lactobacillus casei, yeast, and Bacillus subtilis.

Three-dimensional structure of Gly m 5 (β-conglycinin) plays an important role in its stability and overall allergenicity

To date, there is insufficient knowledge regarding the relationship of the allegenicity and the three-dimensional structure of Gly m 5 (β-conglycinin), a major allergen in soybean. In the present study, allergen Gly m 5 was demonstrated to generate three major digestion-resistant fragments when it was subjected to in vitro digestion. The largest fragment corresponded to the main body of the monomer and two smaller fragments corresponded to the main bodies of two modules of the monomer. Two major protease cleavage sites were located in the regions near to the connection between two modules. Coincidentally, the major digestion-resistant fragments were demonstrated to contain intact IgE epitopes and be capable to induce basophil histamine release in Gly m 5 sensitised piglets, indicating that the three-dimensional structure of Gly m 5 afforded the molecule some protection from complete degradation into small peptides and amino acids, and contributed to its overall allergenicity.

BASALIT trial: double-blind placebo-controlled allergen immunotherapy with rBet v 1-FV in birch-related soya allergy

BACKGROUND

Conflicting results exist on the effect of allergen immunotherapy (AIT) on pollen-related food allergy. We aimed to investigate the efficacy of one-year AIT with the folding variant (FV) of recombinant (r) Bet v 1 on birch-related soya allergy.

METHODS

Of 138 subjects with Bet v 1 sensitization, 82 were positive at double-blind placebo-controlled food challenge (DBPCFC) with soya. A total of 56 of 82 were randomized in the ratio of 2:1 (active: placebo). Per-protocol population (PPP) had received ≥150 μg of allergen or placebo preparation.

OUTCOME MEASURES

lowest observed adverse effect levels (LOAEL), postinterventional occurrence of objective signs (objS) at any dose level, sIgE/IgG4 against Bet v 1 and Gly m 4. Between-group changes were investigated (ancova, Mann-Whitney U-test, Fisher exact test).

RESULTS

Baseline characteristics including LOAELs were comparable in both groups with objS and subjS occurring in 82% and 95% of active (n = 38) vs 78% and 83% of placebo group (n = 18). After AIT, objS occurred in 24% and 47%, respectively. LOAEL group differences showed a beneficial tendency (P = 0.081) for LOAELobjective in PPP (30 active, 15 placebo). sIgG4 raised only in active group (Bet v 1: P = 0.054, Gly m 4: P = 0.037), and no relevant changes occurred for sIgE. Only 56% of the intended sample size was recruited.

CONCLUSION

For the first time, we present data on the effect of rBet v 1-FV on birch-related soya allergy. rBet v 1-FV AIT induced significant immunogenic effects. Clinical assessment showed a tendency in favour of the active group but did not reach statistical significance.

Assessment of endogenous allergenicity of genetically modified plants exemplified by soybean - Where do we stand?

According to EU regulation, genetically modified (GM) plants considered to be allergenic have to be assessed concerning their endogenous allergens before placement on the EU market, in line with the international standards described in Codex Alimentarius. Under such premises, a quantitative relevant increase in allergens might occur in GM plants as an unintended effect compared with conventionally produced crops, which could pose a risk to consumers. Currently, data showing a connection between dose and allergic sensitisation are scarce since the pathophysiological mechanisms of sensitisation are insufficiently understood. In contrast, data on population dose-distribution relationships acquired by oral food challenge are available showing a connection between quantity of allergenic protein consumed and the population of allergic individuals experiencing reactions. Soybean is currently the only recognised allergenic GM food by law for which EFSA has received applications and was therefore taken as an example for defining an assessment strategy. Identification of potential allergens, methodology for quantification as well as risk assessment considerations, are discussed. A strategy is proposed for the identification, assessment and evaluation of potential hazards/risks concerning endogenous allergenicity in food derived from plants developed by biotechnology. This approach could be expanded to other allergenic foods in the future, whenever required.

Development of soybeans with low P34 allergen protein concentration for reduced allergenicity of soy foods

BACKGROUND

In soybean, at least 16 seed proteins have been identified as causing allergenic reactions in sensitive individuals. As a soybean genebank accession low in the immunodominant protein P34 (Gly m Bd 30K) has recently been found, introgression of the low-P34 trait into adapted soybean germplasm has been attempted in order to improve the safety of food products containing soybean protein. Therefore, marker-assisted selection and proteomics were applied to identify and characterize low-P34 soybeans.

RESULTS

In low-P34 lines selected from a cross-population, concentrations of the P34 protein as identified with a polyclonal antibody were reduced by 50-70% as compared to P34-containing controls. Using 2D electrophoresis and immunoblotting, the reduction of P34 protein was verified in low-P34 lines. This result was confirmed by liquid chromatographic-tandem mass spectrometric analysis, which revealed either a reduction or complete absence of the authentic P34 protein as suggested from presence or absence of a unique peptide useful for discriminating between conventional and low-P34 lines.

CONCLUSION

Marker-assisted selection proved useful for identifying low-P34 soybean lines for the development of hypoallergenic soy foods. The status of the P34 protein in low-P34 lines needs further characterization. In addition, the food safety relevance of low-P34 soybeans should be tested in clinical studies. © 2016 Society of Chemical Industry.

The BASALIT multicenter trial: Gly m 4 quantification for consistency control of challenge meal batches and toward Gly m 4 threshold data

SCOPE

The BASALIT clinical trial (EudraCT 2009-011737-27) investigated efficacy of birch allergen immunotherapy on lowest observed adverse effect levels after soy food challenge in patients with birch-associated and Gly m 4 allergen mediated soy allergy. Thus, consistently stable Gly m 4 levels were required in standardized challenge meals.

METHODS AND RESULTS

Soy meal included soy protein isolate (SPI, 88% total protein). A Gly m 4 specific ELISA was developed and validated. Six SPIs and 24 meal batches were analyzed for Gly m 4. (Repeated-measures) analyses of variance were done to identify potential changes between batches and time intervals. Gly m 4 was below the ELISA detection limit (2 ng/mL) in placebo batches. With <20% mean coefficient of variation, Gly m 4 levels were consistent in 24 soy meal batches and within individual 12-wk shelf-life.

CONCLUSION

The novel Gly m 4 specific ELISA proved consistency of challenge meal batches over a 56-month study period. With an average of 178 μg/g Gly m 4 in SPI, Gly m 4 lowest observed adverse effect level can be calculated once clinical lowest observed adverse effect level data based on SPI are available. Hence, sensitivity of patients can be correlated to the relevant allergen content instead of total protein of the allergenic source.

Standardization of double blind placebo controlled food challenge with soy within a multicentre trial

Background

Multicentre trials investigating food allergies by double blind placebo controlled food challenges (DBPCFC) need standardized procedures, challenge meals and evaluation criteria. We aimed at developing a standardized approach for identifying patients with birch related soy allergy by means of DBPCFC to soy, including determination of threshold levels, in a multicentre setting.

Methods

Microbiologically stable soy challenge meals were composed of protein isolate with consistent Gly m 4 levels. Patients sensitized to main birch allergen Bet v 1 and concomitant sensitization to its soy homologue Gly m 4 underwent DBPCFC. Outcome was defined according to presence and/or absence of ten objective signs and intensity of eight subjective symptoms as measured by visual analogue scale (VAS).

Results

138 adult subjects (63.8% female, mean age 38 years) underwent DBPCFC. Challenge meals and defined evaluation criteria showed good applicability in all centres involved. 45.7% presented with objective signs and 65.2% with subjective symptoms at soy challenge. Placebo challenge meals elicited non-cardiovascular objective signs in 11.6%. In 82 (59.4%) subjects DBPCFC was judged as positive. 70.7% of DPBCFC+ showed objective signs and 85.4% subjective symptoms at soy challenge. Subjective symptoms to soy challenge meal in DBPCFC+ subjects started at significantly lower dose levels than objective signs (p < 0.001). Median cumulative eliciting doses for first objective signs in DBPCFC+ subjects were 4.7 g [0.7–24.7] and 0.7 g [0.2–4.7] total soy protein for first subjective symptoms (p = 0.01).

Conclusions

We present the hitherto largest group of adults with Bet v 1 and Gly m 4 sensitization being investigated by DBPCFC. In this type of food allergy evaluation of DBPCFC outcome should not only include monitoring of objective signs but also scoring of subjective symptoms. Our data may contribute to standardize DBPCFC in pollen-related food allergy in multicentre settings.

Trial registration

EudraCT: 2009-011737-27.

Prevalence of sensitization to food allergens and challenge proven food allergy in patients visiting allergy centers in Rawalpindi and Islamabad, Pakistan

In this study, we estimated the prevalence of food allergy in the adult allergic patients of Rawalpindi and Islamabad , Pakistan, based on self-report, skin prick test (SPT) and oral food challenge test (OFC). SPT was used for the estimation of sensitization to wheat, egg, milk, beef, chicken, mutton, fish, corn, lentils, rice, soya, peanut and banana. Among 689 patients, 39.19 % showed sensitivity to one or more foods, where, sensitization to wheat (156; 22.6 %) was highest, followed by egg (148; 21.48 %) and milk (138; 20.03 %). Sensitization to various proteins ranged between 15.53–15.97 %, while lentils, corn, rice, soya and peanut sensitization was 15.4, 16, 12.5, 12 and 11.5 % respectively. Only 7.1 % patients were SPT positive for banana allergen. SPT was performed in patients with self-reported food allergy (341/689) and also with no self-reported history of food allergy (348/689). SPT results were positive in 69.8 % of the self-report group, whereas, in the patients with no self-reported food allergy 9.2 % were found sensitized to one or more tested food allergens. 101 patients were recruited for OFC, 61 % of these were confirmed of food allergy. The prevalence of food allergy in the study population was 9 %. Food specific OFC results show that wheat allergy is affecting 1.6 % (95 % CI 0.9–2.84 %) of the total allergy patients, followed by egg allergy 1.31 % (95 % CI 0.70–2.47 %). Furthermore, corn allergy, rice allergy and peanut allergy were 1.02, 0.87 and 0.73 %, respectively. In conclusion, wheat allergy is the most prevalent, followed by egg, chicken, beef and fish allergy, respectively.

Special endpoint and product specific considerations in pharmaceutical acceptable daily exposure derivation

Recently, a guideline has been published by the European Medicines Agency (EMA) on setting safe limits, permitted daily exposures (PDE) [also called acceptable daily exposures (ADE)], for medicines manufactured in multi-product facilities. The ADE provides a safe exposure limit for inadvertent exposure of a drug due to cross-contamination in manufacturing. The ADE determination encompasses a standard risk assessment, requiring an understanding of the toxicological and pharmacological effects, the mechanism of action, drug compound class, and the dose-response as well as the pharmacokinetic properties of the compound. While the ADE concept has broad application in pharmaceutical safety there are also nuances and specific challenges associated with some toxicological endpoints or drug product categories. In this manuscript we discuss considerations for setting ADEs when the following specific adverse health endpoints may constitute the critical effect: genotoxicity, developmental and reproductive toxicity (DART), and immune system modulation (immunostimulation or immunosuppression), and for specific drug classes, including antibody drug conjugates (ADCs), emerging medicinal therapeutic compounds, and compounds with limited datasets. These are challenging toxicological scenarios that require a careful evaluation of all of the available information in order to establish a health-based safe level.

EAACI Molecular Allergology User's Guide

The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients.

Oral challenge tests for soybean allergies in Japan: A summary of 142 cases

BACKGROUND

Soybeans are one of causative foods for infantile onset allergies in Japan. This study aimed to analyze the results of soybean challenge tests that were conducted over approximately 7 years at our institution. Using the test data, we sought to identify the responses and clinical profiles of patients with soybean allergies, and to investigate the relationship between the responses and soybean sensitization status.

METHODS

Between July 2004 and May 2010, 142 cases (125 patients) underwent food challenge tests (100 g of silken tofu) for the diagnosis of soybean allergy or confirmation of their tolerance. The patients' characteristics, soybean sensitization status, and responses to the challenge tests were retrospectively evaluated.

RESULTS

Among the subjects who underwent the soybean challenge test, the male/female ratio was 1.6 (87/55), and the mean age at the test was 2.8 ± 1.7 years. The positive rate for the challenge test was 38.7%. Induced symptoms were observed in the skin (81.8%), respiratory system (50.9%), and gastrointestinal system/mucosal membrane/anaphylaxis (12.7%). Intramuscular epinephrine was administered to all 7 patients who experienced an anaphylactic reaction. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic efficiency of soybean-specific IgE titers were low for predicting the responses to the challenge test.

CONCLUSIONS

Soybean allergies were diagnosed in only 18% of the subjects with positive sensitization to soybeans. Therefore, soybean-specific IgE titers are not an effective predictor of a positive response to the challenge test.

Position paper of the EAACI: food allergy due to immunological cross-reactions with common inhalant allergens

In older children, adolescents, and adults, a substantial part of all IgE-mediated food allergies is caused by cross-reacting allergenic structures shared by inhalants and foods. IgE stimulated by a cross-reactive inhalant allergen can result in diverse patterns of allergic reactions to various foods. Local, mild, or severe systemic reactions may occur already after the first consumption of a food containing a cross-reactive allergen. In clinical practice, clinically relevant sensitizations are elucidated by skin prick testing or by the determination of specific IgE in vitro. Component-resolved diagnosis may help to reach a diagnosis and may predict the risk of a systemic reaction. Allergy needs to be confirmed in cases of unclear history by oral challenge tests. The therapeutic potential of allergen immunotherapy with inhalant allergens in pollen-related food allergy is not clear, and more placebo-controlled studies are needed. As we are facing an increasing incidence of pollen allergies, a shift in sensitization patterns and changes in nutritional habits, and the occurrence of new, so far unknown allergies due to cross-reactions are expected.

Use of a basophil activation test as a complementary diagnostic tool in the diagnosis of severe peanut allergy in adults

Background

Diagnosis of severe peanut allergy is difficult and delays in making an accurate diagnosis may place the patient at risk. Adults with a history of anaphylaxis must strictly avoid any contact with peanuts or products that may contain traces of peanuts. For these persons, conventional evaluations with skin prick testing (SPT) and IgE tests may not be sufficient to assess the risk of anaphylaxis. Therefore, we investigated whether the basophil activation test (BAT) could be used for the diagnosis of severe peanut allergy in adults. We compared the non-invasive BAT with conventional laboratory diagnostic tests, including SPT and specific IgE to allergen extracts and components, for the diagnosis of severe peanut allergy.

Methods

Forty-seven persons with severe allergy to peanuts and a clinical diagnosis of anaphylaxis (PA-group), 22 subjects with peanut sensitization (PS-group) and 22 control (C-group) subjects, all in the age range of 18–60 years, were recruited retrospectively and prospectively into the study. Thirty-four patients with peanut allergy and 11 peanut-sensitized patients were sensitized to soy, while 36 patients in the PA-group and 20 patients in the PS-group were sensitized to birch pollen. All the patients and control subjects were investigated with BAT and SPT for responses to peanut, soy and birch extracts and their serum samples were assayed for the presence of specific IgE to peanut, soy and birch extracts, as well as IgE to allergen components (ISAC).

Results

In a multivariate factor analysis, severe peanut allergy (PA) was positively associated with SPT to peanut, IgE to peanut, BAT to peanut and IgE to rAra h 1, 2, 3 and 6 peanut components, as well as to soy components (nGly m 5 and nGly m 6). In contrast, peanut sensitization was positively associated with increased levels of IgE to rAra h 8, birch and birch-related components. BAT-detected reactivity to peanut was significantly higher in patients who had a history of severe allergy to peanuts, as compared with patients who were sensitized to peanuts (p < 0.001), and the receiver operating curve (ROC) analysis showed that BAT had high sensitivity and specificity for predicting severe peanut allergy, with a ROC area under the curve of 0.862. However, in the PA-group, the BAT results for peanut correlated only weakly with the levels of IgE to rAra h 1, 2 and 3 and nAra h 6. Study limitations: oral provocation in the patients with a history of severe peanut allergy could not be performed to compare clinical reactivity with the BAT result due to ethical constraints. Neither was it possible to perform BAT with peanut recombinant allergens which were not available at the time the study commenced

Conclusions

BAT is useful in determining the severity of peanut allergy and may be used as a complementary diagnostic tool to ensure accurate diagnosis of severe peanut allergy in adults. Thus, it may reduce the need to subject these patients to further tests, including an open challenge with peanuts.

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-015-0064-9) contains supplementary material, which is available to authorized users.

Comparison of new immunofluorescence method for detection of soy protein in meat products with immunohistochemical, histochemical, and ELISA methods

Soy proteins are commonly used in the food industry thanks to their technological properties. However, soy is, along with cow’s milk, eggs, wheat, peanuts, tree nuts, fish, crustaceans, and molluscs, responsible for around 90% of food allergies, and is also one of the foodstuffs that can cause anaphylaxis. The aim of this work was to compare the immunofluorescence method for the detection of soy protein in meat products purchased from the retail market with other microscopic methods (immunohistochemical and histochemical), with the ELISA reference method and with the confirmatory results. Within the research, 127 meat products purchased in the retail network were examined using the immunofluorescence method used for the detection of soy protein. The method was compared to Enzyme-Linked ImmunoSorbent Assay (ELISA), immunohistochemical, and histochemical methods. According to McNemar’s test, non-compliance between the immunofluorescence method and immunohistochemical method was low. In addition, a significant difference between the fluorescence method and ELISA (P < 0.05) and a highly significant difference between the fluorescence method and histochemical examination (P < 0.01) was found. The immunofluorescence method was also compared with confirmatory results. According to McNemar’s test, non-compliance between the immunofluorescence method and confirmatory results was low. The results showed the possibilities of this new method to detect the content of soy protein in meat products.

A Novel Multipeptide Microarray for the Specific and Sensitive Mapping of Linear IgE-Binding Epitopes of Food Allergens

BACKGROUND

The identification of B-cell epitopes of food allergens can possibly lead to novel diagnostic tools and therapeutic reagents for food allergy. We sought to develop a flexible, low-tech, cost-effective and reproducible multipeptide microarray for the research environment to enable large-scale screening of IgE epitopes of food allergens.

METHODS

Overlapping peptides (15-mer, 4 amino acid offset) covering the primary sequence of either peanut allergen Ara h 1 or all 3 subunits of the soybean allergen Gly m 5 were simultaneously synthesized in-house on a porous cellulose matrix. Identical peptide microarrays created with up to 384 duplicate peptide-cellulose microspots each were investigated for specificity and sensitivity in IgE immunodetection and in direct experimental comparison to the formerly established SPOT™ membrane technique.

RESULTS

The in-house microarray identified with 98% reproducibility the same IgE-binding peptides as the SPOT™ membrane technique. Additional IgE-binding peptides were identified using the microarray. While the sensitivity was increased between 2- and 20-fold, the amount of human serum required was reduced by at least two thirds over the SPOT™ membrane technique using the microarray. After subtraction of the potential background, we did not observe non-specific binding to the presented peptides on microarray.

CONCLUSIONS

The novel peptide microarray allows simple and cost-effective screening for potential epitopes of large allergenic legume seed storage proteins, and it could be adapted for other food allergens as well, to study allergenic epitopes at the individual subject level in large paediatric and adult study groups of food allergic subjects.

Evaluation of basophil allergen threshold sensitivity (CD-sens) to peanut and Ara h 8 in children IgE-sensitized to Ara h 8

Background

Diagnosing peanut allergy properly is important and can be achieved by combining clinical history with various diagnostic methods such as IgE-antibody (IgE-ab) measurements, skin-prick test, basophil allergen threshold sensitivity (CD-sens) and food challenge. We aimed to evaluate CD-sens to peanut, Ara h 8 and Gly m 4 in relation to an oral peanut challenge in children IgE-sensitized to birch, peanut and Ara h 8 avoiding peanuts.

Methods

Twenty children IgE-sensitized to birch pollen and Ara h 8, but not to Ara h 1, Ara h 2 or Ara h 3 were challenged orally with roasted peanuts. Blood samples were drawn for IgE-ab and CD-sens analysis. To measure CD-sens, basophils were stimulated in vitro with decreasing doses of allergens until threshold sensitivity was reached.

Results

All children passed challenge without objective symptoms, but mild oral allergy syndrome (OAS) symptoms were reported in 6/20 children. Nineteen of twenty children were negative in CD-sens to peanut but 17/20 were positive to rAra h 8. Eleven of twenty children were positive in CD-sens to rGly m 4.

Conclusion

Positive CD-sens to rAra h 8 show that the Ara h 8 IgE-ab sensitized basophils can be activated by a rAra h 8 allergen and initiate an allergic inflammation despite a negative challenge. Hence, children sensitized to Ara h 8 but not to peanut storage proteins may be at risk for systemic allergic reaction when eating larger amounts of peanuts but most likely don’t have to fear smaller amounts.

Electronic supplementary material

The online version of this article (doi:10.1186/s12948-014-0007-3) contains supplementary material, which is available to authorized users.

Cross-reactivity between the soybean protein p34 and bovine caseins

Purpose

Soy-based formulas are widely used as dairy substitutes to treat milk allergy patients. However, reactions to soy have been reported in a small proportion of patients with IgE-mediated milk allergies. The aim of this work was to explore whether P34, a mayor soybean allergen, is involved in this cross-reactivity.

Methods

In vitro recognition of P34 was evaluated by immunoblotting, competitive ELISA and basophil activation tests (BAT) using sera from allergic patients. In vivo cross-reactivity was examined using an IgE-mediated milk allergy mouse model.

Results

P34 was recognized by IgE antibodies from the sera of milk allergic patients, casein-specific monoclonal antibodies, and sera from milk-allergic mice. Spleen cells from sensitized mice incubated with milk, soy or P34 secreted IL-5 and IL-13, while IFN-γ remained unchanged. In addition, the cutaneous test was positive with cow's milk proteins (CMP) and P34 in the milk allergy mouse model. Moreover, milk-sensitized mice developed immediate symptoms following sublingual exposure to P34.

Conclusions

Our results demonstrate that P34 shares epitopes with bovine casein, which is responsible for inducing hypersensitivity symptoms in milk allergic mice. This is the first report of the in vivo cross-allergenicity of P34.