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A Comprehensive Review of Legume Allergy
Abstract
Legumes belonging to Fabaceae family of the order Fabales are a rich and important source of proteins and many essential elements. Due to its nutritious elements, these are preferably included in human diet in most part of the world. But, unfortunately, IgE binding proteins have been identified in majority of legumes, and allergenic response to these legumes may range from mild skin reactions to life-threatening anaphylactic reaction. Overall, allergenicity due to consumption of legumes in decreasing order may be peanut, soybean, lentil, chickpea, pea, mung bean, and red gram. So far, several allergens from different legumes have been identified and characterized. Most of identified allergens belong to storage proteins family, profilins, or the pathogenesis-related proteins. Legumes also have property of immunological cross-reactivity among themselves and from other sources that also increases the severity of allergenic response to a particular legume. This review summarizes the currently available knowledge on legume allergy and describes the allergenic problems associated with different legumes. It also tries to explore about the legume allergens identified so far by different scientific groups. The culmination of knowledge about identification and characterization of allergens from different legumes will be helpful in diagnosis and treatment of allergy, for development of novel therapeutic strategies, for strict avoidance of particular legume in diet by susceptible individual and also to produce hypoallergenic cultivars of leguminous crop through conventional breeding or genetic modification.
... Legumes causing allergic reactions differ from country to country. Peanut is the most frequent cause in Northern Europe and the United States of America (USA), whereas lentil is the main cause in Spain (1)(2)(3)(4)(5). Prevalence, clinical signs, and natural course of legume allergies excluding peanut allergy are not widely studied (6). ...
... Patients frequently have another legume allergy or an accompanying different food allergy or aeroallergen sensitization (3)(4)(5)(6)(7)(8)10). Lentil, chickpea, and pea allergies can be seen in a single patient, which may represent the multiplicity of legume allergies (9)(10)(11). ...
... (0-4) 5 (1.[5][6][7][8][9][10][11] 0.20 ...
... In the past few decades, the prevalence of food allergy has been on the rise with up to 10% of the population being affected and a higher prevalence reported in the pediatric population. 1 In European children and adolescents with food allergy, peanut and nuts are the most prevalent allergen sources. 2 The frequency of allergy to other legumes, such as soybean, lentil, pea, and chickpea, shows geographic variations based on dietary habits. 3 Legume seeds and their derived products are increasingly used in food industry due to their nutritional composition and technological properties. They represent an important source of low cost proteins that can be used for the formulation of processed food. ...
... Indeed, allergies and clinical cross-reactivities to lentils, pea, chickpea, and beans have already been reported in the past. 3 Allergen labeling regulations require the declaration of peanut and soybean as allergens in food products. Other legumes, except lupin in Europe and Australia, are exempt of allergen labeling policies. ...
... [10][11][12][13] Furthermore, the high amino acid sequence identity between vicilins leads to IgE-cross-reactivity between different legumes. 3 In the Mediterranean area and in India, cross-reactivity to pea, lentil, and chickpea is common. [14][15][16][17][18] Patients with an allergy to legumes may have an increased risk when ingesting nonpriority legumes such as cowpea because of potential cross-reactive molecules common to different legumes. ...
Background
Novel protein sources can represent a risk for allergic consumers. The aim of this study was to evaluate the allergenicity of cowpea (Vigna unguiculata), an increasingly consumed legume and potential new industrial food ingredient which may put legume‐allergic patients at risk.
Methods
Children with allergy to legumes associated to peanut (LP group: n = 13) or without peanut allergy (L group: n = 14) were recruited and sensitization to several legumes including cowpea was assessed by prick tests and detection of specific IgE (sIgE). Cowpea protein extract was analyzed by SDS‐PAGE and immunoblotting, IgE‐reactive spots were subjected to mass spectrometry. IgE‐cross‐reactivity between cowpea, pea, and peanut was determined using ELISA inhibition assays. Basophil activation tests were performed to evaluate sensitivity and reactivity of patient basophils toward legumes.
Results
Prick tests and sIgE levels to cowpea were positive in 8/14 and 4/13 patients of the L group and in 9/13 and 10/13 patients of the LP group, respectively. Four major IgE‐binding proteins were identified as vicilins and seed albumin. Cowpea extract and its vicilin fraction strongly inhibited IgE‐binding to pea and peanut extract. Peanut, lentil, and pea were the strongest activators of basophils, followed by cowpea, soybean, mung bean, and lupin.
Conclusion
A majority of patients with legume allergy were sensitized to cowpea proteins. Four novel allergens were identified in cowpea, among which storage proteins were playing an important role in IgE‐cross‐reactivity, exposing legume‐allergic patients to the risk of clinical cross‐reactivity to cowpea and thus adding cowpea to the group of nonpriority legumes that are not subjected to allergen labeling such as chickpea, pea, and lentil.
... Allergenicity could represent one of the many risks associated to the increased legume consumption. Indeed, as the global consumption of pulses increases, so does the risk of eliciting allergic reactions in susceptible individuals, also to legumes not yet recognized as major allergens 12 . As a matter of fact, among the 14 allergens officially listed in Annex II of Regulation EC no 1169/2011 and thus requiring mandatory labelling if used as an ingredient, three leguminous crops are present: lupin, soybean, and peanut. ...
... As a matter of fact, among the 14 allergens officially listed in Annex II of Regulation EC no 1169/2011 and thus requiring mandatory labelling if used as an ingredient, three leguminous crops are present: lupin, soybean, and peanut. However, IgE-binding (thus potentially allergenic) proteins have been identified in most legumes, namely pea, bean, lentil, and chickpea, among others [12][13][14][15] . ...
... Allergens derived from leguminous crops mainly belong to three families: storage proteins, which include the prolamin superfamily (including non-specific lipid transfer proteins and 2S storage albumins) and the cupin superfamily (including 7S and 11S globulins), pathogenesis-related proteins (mainly constituted by homologues of the birch pollen allergen Bet v 1) and profilins 12,16 ; all of them can be associated to an immediate hypersensitivity reaction with a different degree of severity 17 . The IgE-binding capacity and thus the allergenic potential of those proteins can be influenced by food processing techniques: their allergenicity may decrease, remain unchanged or even increase upon treatments such as thermal processing, enzymatic hydrolysis, and fermentation 15,18 . ...
The interest in agri-food residues and their valorization has grown considerably, and many of them are today considered to be valuable, under-exploited sources of different compounds and notably proteins. Despite the beneficial properties of legumes by-products, there are also some emerging risks to consider, including their potential allergenicity. In this work the immunoreactivity of chickpea, pea, and white bean by-products was assessed, and whether the production of enzymatic hydrolysates can be an effective strategy to reduce this allergenic potential. The results presented clearly indicate that the efficiency of this strategy is strongly related to the enzyme used and the food matrix. All legume by-products showed immunoreactivity towards serum of legume-allergic patients. Hydrolysates from alcalase did not show residual immunoreactivity for chickpea and green pea, whereas hydrolysates from papain still presented some immunoreactivity. However, for white beans, the presence of antinutritional factors prevented a complete hydrolysis, yielding a residual immunoreactivity even after enzymatic hydrolysis with alcalase.
... Table 2 Antinutrient levels (TIU mg À1 for trypsin and chymotrypsin inhibitors, and mg g À1 DW for the remaining factors) in some pulses The allergenic potential of pulses has been extensively studied in the literature. Common pulses with ability to elicit allergenic responses via ingestion typically include lupin, lentils, peas, chickpeas, black/red gram, mung bean, green bean and red kidney bean (Verma et al., 2013;Rosa-Sibakov et al., 2016;Cuadrado and Pedrosa, 2017;Hoffmann et al., 2017;Bessada et al., 2019). In addition, lupin and products thereof are listed in the Annex II of Regulation (EU) No 1169/2011, among the 14 regulated products causing allergies or intolerances, for which labeling is mandatory. ...
... However, increasing prevalence of pea allergy in the US and UK has been reported, following the increased consumption of pea isolated proteins (Messina and Venter, 2020). Consumption of pulses may trigger mild to life-threatening symptoms, such as oral allergy syndrome, angioedema, vomiting, urticaria, allergic rhinitis, diarrhea, rashes on skin, swelling of the tongue or throat, asthma, and severe anaphylactic reactions in sensitized individuals (Verma et al., 2013;Cuadrado and Pedrosa, 2017). As reported by Bessada et al. (2019), the major allergens in pulses include a-conglutins (legumin-like) and b-conglutins (vicilin-like), and less extensively, g-conglutins (vicilin-like) and d-conglutins (2S albumins). ...
... As reported by Bessada et al. (2019), the major allergens in pulses include a-conglutins (legumin-like) and b-conglutins (vicilin-like), and less extensively, g-conglutins (vicilin-like) and d-conglutins (2S albumins). According to the classification of plant food allergens proposed by Jenkins et al. (2005), which is based on amino acid sequence homology with known allergens, the storage protein family (including cupins and prolamins), profilins, and pathogenesis-related proteins have been identified as the main four protein (super-) families responsible for legume allergenicity (Verma et al., 2013). Due to the presence of structurally homologous proteins, thereby sharing common epitopes, legume species show significant cross-reactivity among themselves, e.g., cross-reactivity with lupin, pea and soy among peanut-allergic patients, but also with other plant allergens, e.g., pollen. ...
Pulse proteins stand as promising food ingredients with the potential to sustainably contribute to the nutritional needs of a growing world population. While benefiting from enhanced functionality and tailored biological activity towards health promotion, safety- and sensory-related issues may challenge the overall acceptability of pulse-based products. This chapter reviews potential food applications of pulse proteins, as well as protein extraction methods. Overall, safer and more sustainable products with enhanced functionality and bioactivity can be achieved when combining traditional and innovative processes. However, further research efforts should be directed towards production cost-effectiveness on an industrial scale and consumer acceptance to fully enable the game-changing market potential of pulse proteins.
... In terms of allergenicity, compared to other legumes, allergic reactions to soybeans and peanuts are relatively common and the allergic reaction can be severe [78,79]. Lentils, chickpeas, peas, mung beans, and red grams have also been reported to have allergenic potential [80,81]. What is most challenging is the fact that legumes exhibit immunological cross-reactivity among themselves as well as with other sources, increasing the severity of an allergenic response, as reported with peanut and lupin [81,82]. ...
... Lentils, chickpeas, peas, mung beans, and red grams have also been reported to have allergenic potential [80,81]. What is most challenging is the fact that legumes exhibit immunological cross-reactivity among themselves as well as with other sources, increasing the severity of an allergenic response, as reported with peanut and lupin [81,82]. For instance, patients who are allergic to peanuts develop allergies to lupin, demonstrating the ability of crossreactivity to trigger an immune response to molecules found in closely related species [82]. ...
A rapidly growing population, resource scarcity, and the future sustainability of our food supply are among the major concerns of today’s food industry. The importance of resilient food crops that will sustain in the future is imperative, and legumes are ideal future food crops owing to their rich nutrient profile, cost-effective production and resource usage efficiency. Furthermore, they have the potential to meet the protein needs of the future. There are however several limitations associated with legumes in terms of their sensory, nutritional, and functional properties, which make them challenging for the food industry to use. In this review, these challenges are discussed in detail with particular reference to fermentation as a strategy for overcoming them. A major focus is on examining the potential application of fermentation for modifying techno-functional properties, such as foaming and emulsifying properties, solubility, and water and oil binding capacities of legume substrates. In many studies, fermentation has been demonstrated to enhance the techno-functional, sensory and nutritional attributes of various legume substrates. Future studies must focus on developing scalable fermentation processes to utilize the technology for improving the techno-functional and sensory properties of legume-based ingredients at industrial scale.
... Various nutritionally important foods cause allergic reactions when consumed [101]. Among legumes, peanut is the source of the highest number of allergic proteins, followed by soybean, lentil, chickpea, pea, mung bean, pigeon pea, and lupin in decreasing order of allergenicity [102,103]. ...
... Of these, cupins and prolamins are seed storage proteins. The properties of various allergic protein families are summarized in Table 7 [101][102][103][104]. Table 7. Major allergic protein families of legumes and their significant characteristics. ...
Legume seed protein is an important source of nutrition, but generally it is less digestible than animal protein. Poor protein digestibility in legume seeds and seedlings may partly reflect defenses against herbivores. Protein changes during germination typically increase proteolysis and digestibility, by lowering the levels of anti-nutrient protease inhibitors, activating proteases, and breaking down storage proteins (including allergens). Germinating legume sprouts also show striking increases in free amino acids (especially asparagine), but their roles in host defense or other processes are not known. While the net effect of germination is generally to increase the digestibility of legume seed proteins, the extent of improvement in digestibility is species- and strain-dependent. Further research is needed to highlight which changes contribute most to improved digestibility of sprouted seeds. Such knowledge could guide the selection of varieties that are more digestible and also guide the development of food preparations that are more digestible, potentially combining germination with other factors altering digestibility, such as heating and fermentation. Techniques to characterize the shifts in protein make-up, activity and degradation during germination need to draw on traditional analytical approaches, complemented by proteomic and peptidomic analysis of mass spectrometry-identified peptide breakdown products.
... namely hydrophobic protein (Gly m 1), defensin (Gly m 2), profilin (Gly m 3), pathogenesis-related protein (Gly m 4), β-conglycinin (Gly m 5), glycinin (Gly m 6), seed biotinylated protein (Gly m 7) and 2S albumin ( Gly m 8). Besides, Gly m Bd 28k, Gly m Bd 30k, trypsin inhibitor, lectin, and Gly 50 kDa have been also confirmed as the common soybean allergens [5]. However, among these soybean protein allergens, only seven of them, i.e., Gly m 4.0101 (Uniprot ID: P26987), Gly m 5.0201 (Uniprot ID: P11827), Gly m 5.03 (Uniprot ID: P25974), Gly m 6.0101 (Uniprot ID: P04776), Gly m 6.0501 (Uniprot ID: P04347), trypsin inhibitor (Uniprot ID: P01070) and lectin (Uniprot ID: P05046) ( Table 1), have been characterized with crystal structures as seen in the Uniprot database (https://www.uniprot.org/). ...
... Previous studies have indicated that soybean allergy is usually mediated by type 2 CD4+ T cells (Th2) [5]. In detail, the T cell epitopes of soybean allergens combine with major histocompatibility complex (MHC) class II proteins, which can be recognized by Th2 cells and induce the release of IL-4, IL-5, IL-13 and other interleukins that promote B cell proliferation and differentiation to produce antibodies, and play an important role in activating mast cells, basophils, and eosinophils [2]. ...
Protein allergens is a health risk for consumption of soybeans. To understand allerginicity mechanism, T cell epitopes of 7 soybean allergens were predicted and screened by abilities to induce cytokine interleukin 4. The relationships among amino acid composition, properties, allergenicity and pepsin hydrolysis sites were analyzed. Among the 138 T cell epitopes identified, YIKDVFRVIPSEVLS, KDVFRVIPSEVLSNS, DVFRVIPSEVLSNSY of Gly m 6.0501 (P04347), and AKADALFKAIEAYLL, ADALFKAIEAYLLAH of Gly m 4.0101 (P26987) were the most possible epitope candidates. In T cell epitopes pattern, the frequencies of amino acids Q, D, E, P and G decreased, while F, I, N, V, K and H increased. Hydrophobic residues at positions p1 and p2 and positively charged residues in positions p13 might contribute to allergenicity. Most of epitopes could be hydrolyzed by pepsin into small polypeptides within 12 residues length, and the anti-digestive epitope regions contained I, V, S, N, and Q residues. T cell epitopes EEQRQQEGVIVELSK from Gly m 5.03 (P25974) showed resistantence to pepsin hydrolysis and would cause a higher Th2 cell response. This research provides basis for the development of hypoallergenic soybean products in the soybean industry as well as for the immunotherapy design for protein allergy.
... Various nutritionally important foods cause allergic reactions when consumed [ 85 ]. Among legumes, peanut is the source of the highest number of allergic proteins, followed by soybean, lentil, chickpea, pea, mung bean, pigeon pea, and lupin in decreasing order of allergenicity [ 86,87 ]. ...
... Of these, cupins and prolamins are seed storage proteins. The properties of various allergic protein families are summarized in Table 8 [ [85][86][87][88]. ...
Legume seed protein is an important source of nutrition, but it is less digestible than animal protein. Poor protein digestibility in legume seeds and seedlings may partly reflect defences against herbivores. Protein changes during germination typically increase proteolysis and digestibility, by lowering the levels of anti-nutrient protease inhibitors, activating proteases, and breaking down storage proteins (including allergens). Germinating legume sprouts also show striking increases in free amino acids (especially asparagine), but their roles in host defence or other processes are not known. While the net effect of germination is generally to increase the digestibility of legume seed proteins, the extent of improvement in digestibility is species and strain dependent. Further research is needed to highlight which changes contribute the most to improved digestibility of sprouted seeds. Such knowledge could guide the selection of varieties that are more digestible, and also guide the development of food preparations that are more digestible, potentially combining germination with other factors altering digestibility, such as heating and fermentation. Techniques to characterize the shifts in protein make-up, activity and degradation during germination need to draw on traditional analytical approaches, complemented by proteomic and peptidomic analysis of mass spectrometry identified peptide breakdown products.
... Besides, 10%-14% of infants with CMA are allergic to soy protein as well (Kattan, Cocco, & Järvinen, 2011;Klemola et al., 2002;Zeiger et al., 1999). Moreover, allergenic cross-reactivity may occur between soybean and other legumes, including e.g., peanut, lentil, lupine, pea, and chickpea, which can be attributed to the presence of shared epitopes within the allergens of these legumes (L'Hocine & Boye, 2007; Verma, Kumar, Das, & Dwivedi, 2013). This emphasizes the need for cautious consideration of allergenicity when developing legume-based IF. ...
... Many studies have demonstrated that cross-reactivity can occur between soy and other legumes (or legume-based food additives), such as peanut, pea, chickpea, lima bean, green bean, white bean, lentil, guar gum, carob bean, tragacanth, and liquorice (L'Hocine & Boye, 2007;Verma, Kumar, Das, & Dwivedi, 2013). According to our results, apart from peanut, pea, chickpea, and lentil that were already mentioned above, potential epitopic peptides from kidney bean and lupine family may cause cross-reactions as well. ...
... Like other legumes, it contains antinutritional substances, especially antinutritional proteins. Soybean is one of eight main foods causing more than 90% food allergies [5]. Several soy allergens have been described: non-specific LTP, defensin, profilin, PR-proteins, vicilin, legumin, 2S albumins, and cysteine proteases [6]. ...
... Allergies exist for certain plant-based proteins, particularly in legumes and nuts. The plant proteins with the highest allergy prevalence include peanuts, soybeans, lentils, chickpeas, and mung beans [132]. Peanut allergies can cause life-threatening symptoms for some with the allergy [133]. ...
Protein inadequacy is a major contributor to nutritional deficiencies and adverse health outcomes of populations in low- and middle-income countries (LMICs). People in LMICs often consume a diet predominantly based on staple crops, such as cereals or starches, and derive most of their daily protein intakes from these sources. However, plant-based sources of protein often contain low levels of indispensable amino acids (IAAs). Inadequate intake of IAA in comparison with daily requirements is a limiting factor that results in protein deficiency, consequently in the long-term stunting and wasting. In addition, plant-based sources contain factors such as antinutrients that can diminish protein digestion and absorption. This review describes factors that affect protein quality, reviews dietary patterns of populations in LMICs and discusses traditional and novel small- and large-scale techniques that can improve the quality of plant protein sources for enhanced protein bioavailability and digestibility as an approach to tackle malnutrition in LMICs. The more accessible small-scale food-processing techniques that can be implemented at home in LMICs include soaking, cooking, and germination, whereas many large-scale techniques must be implemented on an industrial level such as autoclaving and extrusion. Limitations and considerations to implement those techniques locally in LMICs are discussed. For instance, at-home processing techniques can cause loss of nutrients and contamination, whereas limitations with larger scale techniques include high energy requirements, costs, and safety considerations. This review suggests that combining these small- and large-scale approaches could improve the quality of local sources of proteins, and thereby address adverse health outcomes, particularly in vulnerable population groups such as children, adolescents, elderly, and pregnant and lactating women.
... Nevertheless, their consumption could present some risks since certain compounds within them can significantly reduce their quality because they affect protein digestibility and nutrients bioavailability (Stagnari, Maggio, Galieni & Pisante, 2017). These molecules are referred to as antinutritional factors (ANFs), to which enzyme inhibitors, lectins, oligosaccharides, phenolic compounds, phytates and saponins belong (Wijaya, Zakaria, Syah & Prangdimutri, 2015;Verma, Kumar, Das & Dwivedi, 2013). Moreover, IgE binding proteins have been identified in the majority of legumes, thus leading to potential allergic reactions ranging from skin rashes to life-threatening conditions (Anvari, Miller, Yeh & Davis, 2019). ...
Legumes represent a promising nutritional alternative source of proteins to meat and dairy products. Additionally, Novel Foods (Regulation EU 2015/2283) can help meet the rising protein demand. However, despite their benefits, emerging allergenicity risks must be considered. The aim of this work is the molecular characterization of the Novel Food Mung bean protein isolate for allergenicity prediction with High Resolution Mass Spectrometry analysis. The assessment of the allergenicity was evaluated in silico by comparing protein sequences of the Novel Food with other known legume allergens, using bioinformatic databases. The results highlighted similarity higher than 60 % of the protein structure of Mung bean with two known allergens of soybean and pea. Furthermore, enzymatic hydrolysis effects on allergenic potential was evaluated by immunoblotting analysis using sera of patients allergic to legumes. The protein hydrolysates obtained showed a high nutritional quality and a reduced allergenic potential, making them suitable for hypoallergenic food formulations.
... The immunodominant allergic compound in soybean is the protein Gly mBd 30 K/ P34 which is responsible for 65% of the total soy allergic response (Fischer et al., 2020;Verma et al., 2013). Growing concerns about soybean allergenicity have urged scientists toward developing protein fractions from alternate plant sources such as pulses. ...
... Between 2003 and 2017, the frequency of reported illnesses was one per 1.85 million servings and the frequency of possible allergic reactions was one per 24.3 million servings [52]. It is well established that some of the common ingredients in plant-based meat substitutes, such as soy, legumes, and wheat, contain allergens [53,54]. Going forward, it is imperative that adverse reactions to meat alternatives are monitored and tracked, and that product packaging clearly highlights known allergens. ...
Background: Climate change is a serious threat to human wellbeing and development. Global reduction of meat intake is key to addressing climate change and other modern sustainability challenges. Plant-based and mycoprotein-based meat substitutes are predicted to play a key role in the reduction of meat intake; however, their impact on human health is unclear. The main objective of this meta-analysis was to assess the short-term effects of meat substitutes on important cardiometabolic biomarkers (total cholesterol, TC; LDL-cholesterol, LDL-C; HDL-cholesterol, HDL-C; triglycerides, TG; systolic blood pressure, SBP; diastolic blood pressure, DBP; fasting blood glucose, FBG; weight) in controlled clinical trials. Methods: Embase and MEDLINE were searched to identify controlled clinical trials with meat substitute interventions and cardiometabolic biomarker outcomes. Standardised mean differences in TC, LDL-C, HDL-C, TG, FBG, SBP, DBP, and weight and 95% confidence intervals were pooled using a random effects model. Risk of bias, heterogeneity, sensitivity, and publication bias were assessed. Of the 934 records identified, 12 studies met the inclusion criteria. In the pooled analyses, the consumption of meat substitutes was associated with significantly lower TC (−0.50 mmol/L [95% CIs −0.70, −0.29]), LDL-C (−0.39 mmol/L [−0.57, −0.21]), and TG (−0.15 mmol/L [−0.29, −0.01]), non-significantly lower FBG (−0.08 [−0.23, 0.08]), SBP (−0.32 [−1.79, 1.41]), and weight (−0.12 [−1.52, 1.27]), and non-significantly higher HDL-C (0.01 [−0.02, 0.05]) and DBP (0.49 [−0.30, 1.28]). There was evidence of publication bias, and some heterogeneity was detected. The certainty of evidence was moderate for the TC and HDL-C results, low for the LDL-C, TG, SBP, DBP, and weight results, and very low for the FBG results. Conclusions: Replacement of some or all meat with plant-based or mycoprotein-based substitutes may lower TC, LDL-C, and TG.
... Sin embargo, a pesar de que los alergenos de albúmina de semilla 2S comparten similitudes estructurales, Ara h 2 no mostró homología estructural con las regiones correspondientes de nuez de la India Jug r 1, nuez pecana Car i 1 o nuez de Brasil Ber e 1 Aunque existe una teoría de que la reactividad cruzada depende de que los alergenos compartan una secuencia y/o estructura similar, hay datos experimentales que destacan la falta de relación entre el porcentaje de identidad compartida y la acidad de unirse a IgE. 38,39 1. Se demostró una reactividad cruzada frecuente entre Ara h 3 y el otro alergeno de cupina que se encuentra en el cacahuate, Ara h 1, siendo muy poco común la monosensibilización a Ara h 1 y/o Ara h 3. La reactividad cruzada entre diferentes leguminosas se debe a las homologías considerables de las proteínas de almacenamiento de semillas, con Ara h 3 que tiene globulinas similares a leguminosas 11S equivalentes en soja (Gly m glicina 1, 2 y 4), guisante (Pis s 2), lupino (α-conglutina) y el condimento fenogreco (Tri f 3). Se ha informado que la glicinina de soja presenta una alta identidad de secuencia de 62% con la glicinina de cacahuate, Ara h 3. 40 2. Los epítopos de unión a IgE de Ara h 3 demostraron una homología estructural entre los alergenos de leguminosas, cacahuate y frutos secos, específicamente Jug r 4 de nuez, Cor a 9 de avellana y Ana o 2 de anacardo, lo que ayuda a explicar la reactividad cruzada de unión a IgE observada. ...
... And even in comparing peanut and soya bean allergenic responses, peanut allergies are highly prevalent and severe, while soya bean allergies tend to be less intense (Gupta et al., 2019). Pea and lentil allergenic responses are similar to soya bean in places where they are consumed as a staple (Verma et al., 2013). Certainly a comparison of the extent of epitopes mapped on Len c 1, compared to Ara h 1 might suggest a correlation (more epitopes/more potent allergic responses). ...
Legumes represent an affordable high protein, nutrient dense food source. However, the vast majority of legume crops contain proteins that are known allergens for susceptible individuals. These include proteins from the 7S globulin family, which comprise a vast majority of seed storage proteins. Here, the crystal structures of 7S globulins from Pisum sativum L. (pea) and Lens culinaris Medicus (lentil) are presented for the first time, including pea vicillin and convicilin, and lentil vicilin. All three structures maintain the expected 7S globulin fold, with trimeric quaternary structure and monomers comprised of β-barrel N- and C- modules. The potential impact of sequence differences on structure and packing in the different crystal space groups is noted, with potential relevance to packing upon seed deposition. Mapping on the obtained crystal structures highlights significant Ig epitope overlap between pea, lentil, peanut and soya bean and significant coverage of the entire seed storage protein, emphasizing the challenge in addressing food allergies. How recently developed biologicals might be refined to be more effective, or how these seed storage proteins might be modified in planta to be less immuno-reactive remain challenges for the future. With legumes representing an affordable, high protein, nutrient dense food source, this work will enable important research in the context of global food security and human health on an ongoing basis.
... Significant cross-reactivity among legumes is natural because of the presence of structurally homologous proteins that share common epitopes. This has been demonstrated and observed to have pathological symptoms [35]. In the majority of cases, patients were found to be sensitive to more than one legume. ...
... In addition, shared T-cell epitopes have been found among species that do not include soybean such as L. albus and L. angustifolia (Table 9: AB), but not found in L. luteus; A. hypogaea (Table 9A- (Table 9A). These epitopes have been identified as relevant epitopes in previous studies on sensitizations between allergens of different species with similar structure and sequence leading to the development of allergic cross-reactions [38,39]. ...
Food allergies due to eating habits, pollution, and other factors are a growing problem in Western nations as well as developing countries. Symptoms of food allergies include changes in the respiratory and digestive systems. Legumes are a potential solution to the enormous demands for healthy, nutritive, and sustainable food. However,
legumes also contain families of proteins that can cause food allergies. Some of these legumes include peanut, pea, chickpea, soy, and lupine. It has been shown that processing can alter the allergenicity of legumes since thermic and enzymatic resistance
can affect these properties. Cross-reactivity (CR) is an allergy feature of some allergen proteins when the immune system recognizes part of the common share sequences (epitopes) in these allergic proteins. The research about molecular allergy includes comparisons of immunoglobulin E (IgE) and T-cell epitopes, assessment of three-dimensional structure and comparison of secondary structure elements, posttransduction modifications analysis by bioinformatic approach, and post-transduction modifications affecting epitopes properties may facilitate molecular tools to predict protein allergic behavior establishing prevention measurements that could promote the use of legumes and other seeds. This chapter provides an overview of the structural features of the main allergen proteins from legumes and their allergenic potential.
... To date, the primary plant based alternative proteins used in the production of meat and dairy substitute and feeds are soybean derived, because of its high protein content (43.2% dry weight) (Verma et al., 2013). However, the production of soybean is mainly focused in Brazil and America, and it is responsible for deforestation, water pollution and loss of biodiversity (Fearnside, 2001;Henchion et al., 2017;Lima et al., 2019). ...
Sustainable sources of dietary proteins are making their way into the market to reduce the impact of food production on the environment. Considerations from several standpoints are to be made when supporting the dietary shift toward these alternative sources, particularly regarding their nutritional and safety quality. Research is making enormous steps forwards by producing highly valuable proteins with little environmental impact or by turning by-products and wastes into sources of valuable proteins. The chapter will summarize the environmental, nutritional, and safety aspects related to novel foods, including microalgae, plants, insects, microbial, and synthetic-based ingredients. Consumer acceptability is taken into central consideration throughout the chapter being the final user of the novel food ingredients.
... The immunodominant allergic compound in soybean is the protein Gly mBd 30 K/ P34 which is responsible for 65% of the total soy allergic response (Fischer et al., 2020;Verma et al., 2013). Growing concerns about soybean allergenicity have urged scientists toward developing protein fractions from alternate plant sources such as pulses. ...
... In addition, structural traits of legume proteins are of primary importance for their potential allergenicity and toxicity. These adverse effects must be carefully considered to exploit the beneficial effects of proteins and peptides from legume seeds [36]. Known classes of non-digestible bioactive legume protein and peptides are (i) storage proteins 7S and 11S, globulin, prolamin, glutenins from soybean and lupin with ACE-inhibitory properties, hypotensive, anticarcinogenic and antiinflammatory activities [37][38][39]; (ii) lectins (carbohydrate-binding proteins) characterised by a tight β-sandwich structure that allows them to survive the acidic environment of the digestive tract where lectins exert anti-cytotoxic and anticancer activities [40]; (iii) glycated pea storage protein that is able, at least partially, to escape digestion and act as a modulator of the bacterial metabolic activities and their adhesive potentials [41]; (iv) α-amylase inhibitor from the white bean as an active agent in weight loss and glycaemic control [42]; and (v) protease inhibitor with anticarcinogenic activities [43]. ...
Several global health risks are related to our dietary lifestyle. As a consequence of the overconsumption of ultra-processed and highly digestible protein (150–200% of the recommended value), excess dietary proteins reach the colon, are hydrolysed to peptides and amino acids by bacterial proteases and fermented to various potentially toxic end products. A diet reformulation strategy with reduced protein content in food products appears to be the most effective approach. A potential approach to this challenge is to reduce food digestibility by introducing resistant protein into the diet that could positively influence human health and gut microbiome functionality. Resistant protein is a dietary constituent not hydrolysed by digestive enzymes or absorbed in the human small intestine. The chemical conformation and the amino acid composition strictly influence its structural stability and resistance to in vivo proteolysis and denaturation. Responding to the important gap in our knowledge regarding the digestibility performance of alternative proteins, we hypothesise that resistant proteins can beneficially alter food functionality via their role in improving metabolic properties and health benefits in human nutrition, similar to fibres and resistant starches. A multidisciplinary investigation of resistant protein will generate tremendous scientific impact for other interlinked societal, economic, technological and health and wellbeing aspects of human life.
... Moreover, legume consumption is increasing worldwide due to their high protein content, low levels of unsaturated fats, low cost of production, and the desire to achieve a more vegetarian, healthy, and sustainable diet. [3][4][5] Previous studies have reported the risk of cross-reactivity between peanut allergy (PA) and other legumes, but in a small number of patients, with little data regarding the relevance of sensitization. [6][7][8][9][10] Nevertheless, seed storage protein allergens, members of the cupin, and prolamin superfamily (e.g., 7S and 11S globulins or 2S albumin) are similar allergens to legumes. ...
Background
Legume consumption has increased during the two past decades. In France, legumes are responsible for 14.6% of food‐related anaphylaxis in children, with peanut as the main allergen (77.5%). Few studies have demonstrated cross‐reactivities between peanut and other legumes. The aim of this study was to determine prevalence and relevance of sensitization to legumes in peanut‐allergic children.
Methods
All children, aged of 1–17 years, admitted to the Pediatric Allergy Department of the University Hospital of Nancy between January 1, 2017 and February 29, 2020 with a confirmed peanut allergy (PA) and a documented consumption or sensitization to at least one other legume were included. Data were retrospectively collected regarding history of consumption, skin prick tests, specific immunoglobulin E (IgE), prior allergic reactions, and oral food challenges for each legume.
Results
Among the 195 included children with PA, 122 were sensitized to at least one other legume (63.9%). Main sensitizations were for fenugreek (N = 61, 66.3%), lentil (N = 38, 42.2%), soy (N = 61, 39.9%), and lupine (N = 63, 34.2%). Among the 122 sensitized children, allergy to at least one legume was confirmed for 34 children (27.9%), including six children who had multiple legume allergies (4.9%). Lentil, lupine, and pea were the main responsible allergens. Half of allergic reactions to legumes other than peanut were severe.
Conclusion
The high prevalence of legume sensitization and the frequent severe reactions reported in children with PA highlight that tolerated legume consumption should be explored for each legume in the case of PA, and sensitization should be investigated if not.
... Commonly consumed legumes include alfalfa, clover, pea, beans, lentils, lupins, mesquite, carob, soy, red gram, mung bean, red kidney bean, chickpea, and peanuts. 1 The epidemiology of different legume allergies, as well as their clinical cross-reactivity, varies among different jurisdictions, mainly influenced by the consumption pattern of various legumes. 2 Soy allergy is common in Israel and Australia. ...
Legumes other than peanut are an important source of protein and consist of a wide variety of species, such as soy, peas, chickpeas, lentils, and lupin. Due to their health benefits and the rising popularity of veganism, legume consumption has increased. Legume allergy, cross-sensitization, and cross-reactivity between different species have been reported in the literature and are increasingly recognized. Unlike peanut, oral immunotherapy (OIT) for nonpeanut legumes has not been well studied and published protocols are lacking. Future studies are needed to provide real-world data on the safety and effectiveness of nonpeanut legume OIT, and whether desensitization to one legume leads to desensitization to other legumes in patients with multiple legume allergy. Nevertheless, due to the abundance of clinical trial and real-world data for peanut OIT, it is reasonable to use protocols that substitute peanut protein with other legume protein when desensitizing individuals with nonpeanut legume allergy. Clinicians who are starting to offer legume OIT in their practices may consider starting with preschoolers, an age group for whom real-world data has shown the greatest safety and effectiveness.
... Soybean is widely used in the world due to its high protein content, especially with the rise of the vegan diet. Soybean allergy (type-I hypersensibility reaction) has a prevalence of 0.4% Verma et al., 2013), but does not usually cause lifethreatening events. ...
Food allergies are a growing health problem that generate high costs for health systems. Food allergies have a prevalence of 6-8% in children and 2-3% in adults, which is increasing in the last 10 years due to industrialization. The wide variety of ingredients containing food allergens, in combination with the high number of product formulations and processing methods to produce food makes allergen detection a challenge. It is important to highlight that even trace amounts of allergens are able to elicit allergic reactions and the commercialization of food products with a potential health risk is forbidden (European Union Regulation (EU) 178/2002). Hence, precautionary allergen labeling must be provided in the different food products. In addition, this creates a real need for the development of highly sensitive and reliable techniques that allow the detection and quantification of multiple allergens present in trace amounts. This, together with the possibility to perform new allergen discovery studies (shotgun proteomics), makes Proteomic approaches a widely used methodology in this field. In this chapter we summarize the current knowledge regarding food allergies and the proteomic studies performed for the analysis of the different allergens. We briefly describe immunological processes underlying the different types of food allergies, the causative allergens involved in these processes, as well as the different proteomic approaches developed to identify (e.g., LC-MS/MS) and quantify (e.g., targeted proteomics such as selected/multiple reaction monitoring, SRM/MSM) these allergens in different conditions (e.g., complex mixtures, ultra-processed food, etc). Moreover, we have performed a comprehensive review of the different allergens and proteomic studies carried out in the field of plant food allergies, including gluten related disorders (GRDs), pollen-fruit allergy syndrome (PFAS), legumes allergy, and tree-nuts allergy, as well as animal food allergies, including cow´s milk, red meat, egg, fish, and shellfish allergies.
... 22 The pattern of sensitization to legumes varies geographically according to consumption pattern and exposure to pollens. 23,24 For many of them, commercial tests are already available to measure specific serum IgE in vitro and in vivo (skin prick test [SPT]). Routine skin tests for legumes are limited to chickpeas, mixed beans, lentils (not specified), and peas. ...
Vegetarianism is becoming a common practice among people. Products of vegetable origin are also on the rise, such as vegetable “milk” and legume-based snacks, which may lead to legume sensitivity and allergies in vegetarian diet followers. Furthermore, products derived from legumes, such as lupin flour or fenugreek powder, are often used as food additives. They function as hidden allergens, not always evident on the precautionary labeling, favoring aller-gic reactions. As dietary allergen restriction is the fundamental pillar in managing patients with food allergies, this review aims to reflect on practical aspects—diagnosis and nutritional management—in managing legume allergies in vegetarians, aiming to reduce the negative nutritional impact of an even more restrictive diet.
... The plant protein allergens are associated with three families of the proteins-namely, prolifins, storage proteins and pathogenesis-related proteins. These allergens elicit IgE-mediated immunological reactions resulting in several respiratory, gastrointestinal, skin-related and cardiovascular ailments (Verma et al., 2013;Hadi and Brightwell, 2021). Several studies have revealed that thermal processing, ultrasound treatment, high pressure processing etc. ...
The discussion about the development and consumption of plant-based meat alternatives has been raised since numerous decades and has become the topic of prime concern these days. Recently, the market of plant-based meat alternatives has enormously expanded. With the aim of investigating the present scenario of research on meat analogs and defining the future research areas, reasons for shifting the trends towards consumption of meat analogs due to several health and environmental issues, potential sources and technologies needed for the development of meat analogs, physicochemical properties of meat analogs, functionality of ingredients used for manufacturing plant-based meat analogs, gastrointestinal fate of meat analogs and resulting consumer acceptability are summarized in this review. Studies have revealed that various health and environmental concerns are associated with the meat production which is the key driving force for the development of meat analogs. Recently, modern structuring techniques of plant-based meat alternatives have improved their functionality, however, a need exists to focus on improving the functionality, sensory characteristics, safety, and selection of suitable ingredients for the production of meat analogs. Additionally, the consumers’ acceptability towards meat analogs is quite unsatisfactory which needs to be improved through proper research and creating awareness. Moreover, the gastrointestinal fate of the plant-based meat analogs needs further investigation in order to have a better understanding regarding the nutrient bioavailability of these products. The present review will be helpful in highlighting the current situation regarding the fate of meat analogs and opening new horizons of research in this domain.
... Furthermore, several legumes such as peanut, soybean, lupin, lentil, chickpea, and pea have been described to contain allergenic proteins, which can affect the cutaneous, respiratory, cardiovascular, and gastrointestinal systems of consumers. Most of these identified allergens belong to storage proteins family, profilins, or the pathogenesis-related proteins, and some of them are protease resistant and heat stable [56] ; however, the identification and characterization of legume allergens and their stability to processing conditions require further investigation. ...
There has been a growing demand towards alternative protein sources due to population growth and increasing consumer awareness on sustainability and environmental issues. Proteins from various plant, marine, insect and microbial sources are considered as excellent alternatives to substitute traditional animal-based proteins due their relatively low cost, sustainable production and nutritional value. This work is an overview of the physicochemical properties, functionality and nutritional quality of novel protein sources. Current information on the proximate composition, amino acid profile, digestibility, physicochemical
and functional properties is presented. Effects of extraction method
applied for obtaining protein ingredients from novel sources on protein
composition, functionality and nutritional quality are discussed. Findings of some of the recent studies focusing on modification of protein structure and improvement of functionality are reviewed. Potential end product applications and challenges related to the production and use of protein ingredients obtained from novel sources are discussed. Furthermore, future research recommendations are presented.
... As expected, phylogenetic analysis with the same protein group homologs from different members of the Fabaceae family reveals close evolutionary relationships ( Supplementary Fig. 1). This result is in agreement with earlier studies that showed plant allergen homologs shared highly conserved sequences (Arora, Kumar, Singh, & Singh, 2020;Verma, Kumar, Das, & Dwivedi, 2013). ...
Among legumes, the lentil (Lens culinaris) is a major dietary component in many Mediterranean and Asian countries due to its high nutritional value, especially protein. However, allergic reactions triggered by lentil consumption have also been documented in many countries. Complete allergens profiling is critical for better management of lentil food allergies. Earlier studies suggested Len c 1, a 47kDa vicilin, Len c 2, a seed-specific-biotinylated 66-kDa protein, and Len c 3, low molecular weight lipid transfer proteins (LTPs) were major allergenic proteins in lentils. Recently, mass-spectrometry-based proteomic platforms successfully identified proteins from lentil samples homologous to known plant allergens. Furthermore, in silico analysis using 337 protein sequences revealed lentil allergens that have not previously been identified as potential allergens in lentil. Herein, we discuss the feasibility of omics platforms utilized for lentil allergens profiling and quantification. In addition, we propose some future strategies that might be beneficial for profiling and development of precise assays for lentil allergens and could facilitate identification of the low allergen-containing lentil cultivars.
Mung bean contains up to 32.6% protein and is one of the great sources of plant-based protein. Because many allergens also function as defense-related proteins, it is important to determine their abundance levels in the high-yielding, disease-resistant cultivars. In this study, for the first time, we compared the seed proteome of high-yielding mung bean cultivars developed by
a conventional breeding approach. Using a label-free quantitative proteomic platform, we successfully identified and quantified a
total of 1373 proteins. Comparative analysis between the high-yielding disease-resistant cultivar (MC5) and the other three cultivars showed that a total of 69 common proteins were significantly altered in their abundances across all cultivars. Bioinformatic analysis of these altered proteins demonstrated that PDF1 (a defensin-like protein) exhibited high sequence similarity and epitope matching with the established peanut allergens, indicating a potential mung bean allergen that showed a cultivar-specific response. Conversely, known mung bean allergen proteins such as PR-2/PR-10 (Vig r 1), Vig r 2, Vig r 4, LTP1, β-conglycinin, and glycinin G4 showed no alternation in the MC5 compared to other cultivars. Taken together, our findings suggest that the known allergen profiles may not be impacted by the conventional plant breeding method to develop improved mung bean cultivars.
The world’s growing population and evolving food habits have created a need for alternative plant protein sources, with pulses playing a crucial role as healthy staple foods. Dry beans are high-protein pulses rich in essential amino acids like lysine and bioactive peptides. They have gathered attention for their nutritional quality and potential health benefits concerning metabolic syndrome. This review highlights dry bean proteins’ nutritional quality, health benefits, and limitations, focusing on recent eco-friendly emerging technologies for their obtaining and functionalization. Antinutritional factors (ANFs) in bean proteins can affect their in vitro protein digestibility (IVPD), and lectins have been identified as potential allergens. Recently, eco-friendly emerging technologies such as ultrasound, microwaves, subcritical fluids, high-hydrostatic pressure, enzyme technology, and dry fractionation methods have been explored for extracting and functionalizing dry bean proteins. These technologies have shown promise in reducing ANFs, improving IVPD, and modifying allergen epitopes. Additionally, they enhance the techno-functional properties of bean proteins, making them more soluble, emulsifying, foaming, and gel-forming, with enhanced water and oil-holding capacities. By utilizing emerging innovative technologies, protein recovery from dry beans and the development of protein isolates can meet the demand for alternative protein sources while being eco-friendly, safe, and efficient.
Plant-based meat alternatives have been considered from past years, but recently gained much importance in research development and food industries. Concerns related to health, animal welfare, ethical beliefs and environment act as a driving force for the production of protein-based meat analogues. The major challenging work in the development of plant-based meat is to imitate the texture of meat analogues. The production of plant-based meat analogue needs an astute choice and formulation of constituents to perfectly mimic the fibrous texture of meat. Various plant-based constituents like texturized and non-texturized proteins, fats and oils, thickening agents, binding agents, colouring and flavouring agents used with different processing technologies (extrusion, electrospinning, wet-spinning, shear cell, freeze structuring and 3D-printing) for the production of plant-based meat analogues. This critical review highlights essential ingredients for creating these novel meat analogues, emphasizing protein sources, ingredient functionality, production technologies and health and environmental effects of plant-based meat and consumer acceptance towards plant-based meat.
The demand for high‐quality alternative food proteins has increased over the last few decades due to nutritional and environmental concerns, leading to the growing consumption of legumes such as common bean, chickpea, lentil, lupin, and pea. However, this has also increased the quantity of non‐utilized byproducts (such as seed coats, pods, broken seeds, and wastewaters) that could be exploited as sources of ingredients and bioactive compounds in a circular economy. This review focuses on the incorporation of legume byproducts into foods when they are formulated as flours, protein/fiber or solid/liquid fractions, or biological extracts and uses an analytical approach to identify their nutritional, health‐promoting, and techno‐functional properties. Correlation‐based network analysis of nutritional, technological, and sensory characteristics was used to explore the potential of legume byproducts in food products in a systematic manner. Flour is the most widely used legume‐based food ingredient and is present at levels of 2%–30% in bakery products, but purified fractions and extracts should be investigated in more detail. Health beverages and vegan dressings with an extended shelf‐life are promising applications thanks to the techno‐functional features of legume byproducts (e.g., foaming and emulsifying behaviors) and the presence of polyphenols. A deeper exploration of eco‐friendly processing techniques (e.g., fermentation and ohmic treatment) is necessary to improve the techno‐functional properties of ingredients and the sensory characteristics of foods in a sustainable manner. The processing of legume byproducts combined with improved legume genetic resources could enhance the nutritional, functional, and technological properties of ingredients to ensure that legume‐based foods achieve wider industrial and consumer acceptance.
Введение: Современные мировые тенденции употребления растительного и животного белка склоняют мировое общество в сторону превалирования потребления продуктов питания, обогащенных растительным белком. Это связано с несколькими преобладающими аспектами: получение растительного белка является более экономически выгодным, экологически безопасным и потенциально несет более ценную пищевую компоненту. Известно, что растительный белок усваивается в организме на уровне 61-80% в виду наличия антипитательных веществ и имеет неполноценный аминокислотный состав. Следует изыскивать новые научные подходы повышения биодоступности пищевых компонентов растительного белкового сырья.
Объекты и методы исследования: В статье приводится поэтапный алгоритм проектирования белоксодержащего пищевого продукта с включением в стадию разработки способа снижения антипитательных свойств растительного сырья. В качестве белкового ингредиента выбран горох, который подвергался тонкому измельчению совместно с ферментативным препаратом с последующей стадией ферментативного гидролиза при оптимальных параметрах. Гороховый гидролизат использовали в замесе дрожжевого опарного теста.
Результаты и их обсуждение: На процесс замеса теста оказывает влияние ряд факторов, которые описаны в работе в виде параметрической схемы технологического процесса. На основе структурно-параметрический анализа проведен комплексный эксперимент влияния двух варьируемых факторов (количества дрожжей и гидролизата) на количество сухого нерастворимого остатка.
Выводы: Выведено уравнение регрессии, которое позволяет анализировать технологический процесс и контролировать его. В статье приводятся данные по содержанию водорастворимых веществ, белка, свободных аминокислот в готовых хлебобулочных изделиях, которые позволяют судить об эффективности стадии механоферментативного гидролиза. Общее количество водорастворимых веществ в образцах с гидролизатом увеличивается более, чем в 2 раза. Разработка новых изделий с применением стадии ферментации – это перспективное направление индустрии питания, которое позволяет получать качественно новые изделия с высокой пищевой и биологической ценностью.
La alergia alimentaria se ha venido incrementando a nivel mundial, afectando alrededor del 1,5 % a 2,5 % de los adultos y 6 % de los niños, y tiene un gran impacto en la calidad de vida de los pacientes y sus cuidadores, debido a las dietas de restricción. Los alérgenos más prevalentes son la leche, el huevo, el trigo, la soja, los frutos secos, el maní, el pescado y los mariscos. Las leguminosas mejor estudiadas son el maní y la soja; otras leguminosas como las lentejas, garbanzos y arvejas representan la quinta causa de alergia alimentaria en el área mediterránea, en Turquía y en la India, siendo menos prevalentes en otras áreas geográficas. La alergia a las leguminosas es una entidad infrecuente en Colombia, se desconoce la prevalencia en el país. Describimos los primeros dos casos de anafilaxia por lentejas reportados en el país. Ambos pacientes menores de 18 años, con reacciones adversas tras la ingesta de leguminosas, en las cuales se demuestra alergia mediada por IgE a las lentejas y además sensibilización en el primer caso a las arvejas y garbanzos, y en el segundo caso a los frijoles. Diferentes datos sobre la prevalencia se han descrito en varias áreas geográficas, siendo mayor en países con dietas mediterráneas. Las reacciones mediadas por IgE suelen aparecer incluso con el alimento altamente cocido, debido a la termo-estabilidad de las proteínas. La reactividad cruzada más frecuente se relaciona con los garbanzos y las arvejas.
Purpose
Allergy to legumes and tree nuts (TNs) is one of the most important causes of fatal and near-fatal food-induced allergic reactions. However, our knowledge of the clinical features of legumes and TNs allergies in children is limited. In this study, we aim to identify clinical characteristics, development of tolerance, risk factors of legumes and TNs allergies in children.
Methods
This retrospective study was designed at two cities at the west part of Turkey. Fifty-seven children with legumes and TNs diagnosed at Clinic of Pediatric Allergy of Balikesir University and Dr Behcet Uz Children Hospital for 2014–2018 years were examined. Current age, gender, age of onset of the legumes and/or TN allergy, the type of the allergic reactions, family history of atopy, results of skin prick test (SPT), and/or oral challenge test and presence of concomitant food allergies, tolerance development and cross reactions were recorded.
Results
In total, 83 allergies related with legumes and TNs were determined in 57 patients. Mean age of patients was 18.75 ± 13 months and 40.4% were girl. Fifty-two of these reactions were related with legumes (62.6%) and 29.9% of patients had reaction with more than one. Peanut allergy was most common in legumes allergy (53.8%) and walnut allergy was most common in TNs allergy (54.8%). Urticaria was most common type of allergic reaction (56.6%), 28.9% of reactions were anaphylaxis. No statistically significant difference was found between legumes and TNs in terms of the frequency of development of anaphylaxis (P = 0.062). Concomitant food allergy was present 80.7% of patients. Patients with legume allergy had significantly high hazelnut and walnut allergy (P = 0.04, P < 0.001, respectively). Significantly, high peanut and lentil allergy were detected in patients with TNs allergy (P = 0.01, P = 0.026, respectively). There was co-sensitization and co-allergy between legumes and TNs in children as expected. Tolerance development was shown in 12.2% of patients.
Conclusions
In addition to other food allergies, legumes/TNs allergies are also observed to occur with increasing frequency in children. Co-sensitization and co-allergy between legumes and TNs are frequent. Tolerance development for legumes/TNs allergies is expectedly low.
Non-specific lipid transfer proteins (nsLTPs) are small proteins abundant in plants, which function in transferring phospholipids and galactolipids across the membrane. nsLTPs also play a key role in plant resistance to biotic and abiotic stresses, growth and development, as well as in sexual reproduction, seed development,
and germination. In addition, these proteins have previously been identified as food allergens. In the present study, we carried out a molecular and functional comparative characterisation of 25 sequences of nsLTPs of lupin legumes and other species. Extensive analysis was carried out; including comparison of databases,
phylogeny, physical–chemical properties, functional properties of post-translational modifications, protein structure conservation, 2-D and 3D modelling, functional interaction analysis, and allergenicity including identification of IgE, T-cell, and B-cell binding epitopes. The results indicated that particular structural features of nsLTPs are essential to the functionality of these proteins, high level of structural
stability and conservation. Information about different functional interactions between nsLTPs and ligands showed that nsLTPs can accommodate several of them with different structure; and that the relationship between structure and allergenicity was investigated through the identification of epitopes susceptible of being involved in cross-reactivity between species of the Fabaceae family.
Food allergies affect up to 6% of young children and 3%-4% of adults. They encompass a range of disorders that may be IgE and/or non-IgE mediated, including anaphylaxis, pollen food syndrome, food-protein-induced enterocolitis syndrome, food-induced proctocolitis, eosinophilic gastroenteropathies, and atopic dermatitis. Many complex host factors and properties of foods are involved in the development of food allergy. With recent advances in the understanding of how these factors interact, the development of several novel diagnostic and therapeutic strategies is underway and showing promise.
Peanuts contain some of the most potent food allergens known to date. Ara h 1 is one of the three major peanut allergens. As a first step towards three-dimensional structure elucidation, recombinant Ara h 1 core region was cloned, expressed in Escherichia coli and purified to homogeneity. Crystals were obtained using 0.1 M sodium citrate pH 5.6, 0.1 M NaCl, 15% PEG 400 as precipitant. The crystals diffracted to 2.25 A resolution using synchrotron radiation and belonged to the monoclinic space group C2, with unit-cell parameters a=156.521, b=88.991, c=158.971 A, beta=107.144 degrees. Data were collected at the BL-38B1 station of SPring-8 (Hyogo, Japan).
On the basis of Osborne’s solubility classification (see Chapter 1), pea (Pisum sativum and its wild relative P. fulvum) seeds contain two major classes of protein — water-soluble albumins and salt-soluble globulins. The albumins are heterogeneous, consisting of a large number of relatively minor proteins; the majority of pea seed protein is globulin, or storage protein, but it has been suggested on the basis of their concentration that some albumins may have a storage function (Murray, 1979).
Legumes are dicotyledonous plants belonging to the Fabales order. The main distinctive characteristic of which is their fruit (legumen, seeds contained in pods). This botanical order is formed by three families: Mimosaceae, Caesalpiniaceae and Papilionaceae or Fabacea. The Papilionaceae family includes the most important allergenic species: Lens culinaris (lentil), Cicer arietinum (chick-pea), Pisum sátivum (pea), Arachis hipogea (peanut), Phaseolus vulgaris (bean) y Glycine max (soy).
Legumes are an important ingredient in the Mediterranean diet. Among Spanish children, sensitivity to legumes is the fifth most prevalent food allergy. Lentil and chick-pea are the most frequent cause of allergic reactions to legumes in Spanish children. Legumes could be involved in severe allergic symptoms.
The different legumes have structurally homologousproteins, but they are not all equally allergenic,thus making it difficult to distinguish in vitro and invivo cross-reactivity. We have demonstrated by skintests and CAP that most of the patients are sensitisedto more than one species. We have demonstrateda great degree of cross-reactivity among lentil,chick-pea, pea and peanut by ELISA inhibition (> 50%max. inhibition). Unlike the Anglo-Saxons population,this phenomenon implies clinical sensitisation formany Spanish children. The majority of our patientshave had symptoms with more than one legume (median3 legumes). Thirty-nine patients were challenged(open or simple blind) with two or more legumes and32 (82 %) reacted to two or more legumes: 43,5%to 3, 25,6 % to 2, 13 % to 4 legumes. Seventy threeper cent of the patients challenged with lentil and peahad positive challenge to both, 69,4 % to lentil andchick-pea, 60 % to chick-pea and 64,3 % to lentil,chick-pea and pea simultaneously. Peanut allergy peanutcan be associated to allergy to lentil, chick-peaand pea but less frequently. Contrarily, white beanand overall green bean and soy are well tolerated bychildren allergic to other legumes.
In our study, 82 % of the children allergic to legumes had a sensitisation to pollen. Pea and bean are the legumes with more in vitro cross-reactivity with Lolium perenne, Olea europea and Betula alba. This cross-reactivity could be because of common antigenic determinants or due to the coexistence of pollen and legume allergy. Panallergens implication seems to be less probable.
It is important to emphasize that in spite of an evident clinical and immunological cross-reactivity, the diagnosis of legume allergy should not be based only on specific IgE tests. The decision to eliminate one legume from the diet should be based on a positive oral food challenge.
P34 is an outlying member of the papain-superfamily of cysteine proteases that is expressed in developing soybean [Glycine max (L.) Merr.] seeds and may be involved in the defense against Pseudomonas infection. P34 is the major human allergen of soybean seeds and is present in processed food products that contain soybean protein. We have surveyed a core collection of soybean accessions using a monoclonal antibody against P34 and with human sera from soybean-sensitive individuals. We found that the accessions of soybean surveyed contain similar levels of P34 and that P34 is the major allergenic protein. We have also surveyed wild relatives of soybean and found that P34 was present in the examples assayed. These results indicate that it may not be possible to eliminate P34 from the food supply by breeding with an improved germplasm base.
Information on the comparative digestibility of food allergens and nonallergenic proteins is crucial when stability to digestion is to be used as a criterion to assess the allergenic potential of novel proteins. In this work, we compared the digestive stability of a number of food allergens and proteins of unproven allergenicity and examined whether allergens possess a higher stability than nonallergenic proteins of similar cellular functions, and whether there is a correlation between protein digestibility and allergenicity. The stability of groups of storage proteins,. plant lectins, contractile proteins, and enzymes, both allergens and proteins with unproven allergenicity, in a standard simulated gastric fluid and a standard simulated intestinal fluid was measured. Food allergens were not necessarily more resistant to digestion than nonallergenic proteins. There was not a clear relationship between digestibility measured in vitro and protein allergenicity.
Lupine flour (lupinus albus), recently authorized in France in human food, cross-reacts with peanuts. We report a case of acute asthma in a patient with allergy to peanuts.
Exegesis
This patient has a severe allergy to peanuts, presenting as acute asthma. Skin pricktests to raw and cooked lupine flour were positive. The level of specific-IgE (Allerbio, France) to lupine flour were high. Oral challenge test induced acute asthma at a dose of 965 mg of lupine flour. This quantity may be included in 100 g of bread.
Conclusion
This case report points out the fact that lupine flour is a high-risk allergen in patients presenting allergy to peanuts. It is necessary to evaluate the allergenic risk of new foods before their introduction into human daily food intake and to establish a network of allergy vigilance.
Tremendous progress has been made in our understanding of food-based allergic disorders over the past 5 years. Recent epidemiologic studies suggest that nearly 4% of Americans are afflicted with food allergies, a prevalence much higher than appreciated in the past. In addition, the prevalence of peanut allergy was found to have doubled in American children less than 5 years of age in the past 5 years. Many food allergens have been characterized at the molecular level, which has contributed to our increased understanding of the immunopathogenesis of many allergic disorders and might soon lead to novel diagnostic and immunotherapeutic approaches. The management of food allergies continues to consist of educating patients on how to avoid relevant allergens, to recognize early symptoms of an allergic reaction in case of an accidental ingestion, and to initiate the appropriate emergency therapy. However, the recent successful clinical trial of anti-IgE therapy in patients with peanut allergy and the number of immunomodulatory therapies in the pipeline provide real hope that we will soon be able to treat patients with food allergy.
Allergenicity potential of redkidneybeans (Phaseolus vulgaris cv chitra) was assessed and attempts were made to identify the responsible proteins by pepsin digestibility assay and IgE immunoblotting. To evaluate allergenic potential, BALB/c mice were sensitized with redkidneybean proteins and levels of specific immunoglobulin, histamine, mast cell protease-1, cytokines and CCL-2 were measured. To confirm our findings in BALB/c, the studies were also extended to human subjects. Human sera collected from control subjects and allergic patients after skin prick test were used for IgE immunoblotting, measuring the levels of total and specific IgE and determining cross reactivity of redkidneybean with other legumes. Redkidneybean allergenic potential was evident by significant increase in specific IgE, IgG1, histamine, mast cell protease-1 and Th2 cytokine levels in comparison to control. Enhanced level of eosinophils in jejunum, prominent anaphylactic symptoms, and eruptive histopathological changes give indication towards redkidneybeans allergenicity. IgE immunoblotting detected five protein components with molecular weights of approximately 170, 100, 43, 34 and 20 kDa. Redkidneybean proteins showed cross reactivity with peanut, soybean, chickpea and black gram. Finally, this work demonstrated that redkidneybeans may induce allergic response in mice similar to human subjects, with identification of five clinically relevant allergenic protein components.
A large number of food allergens, usually proteins capable of inducing allergic symptoms, including severe, even life-threatening reactions in predisposed individuals, have been identified and characterized. As most of these proteins are from our daily dietary intake, they are often difficult to avoid. However, the proteins that cause such immunoglobulin E (IgE)-mediated reactions can be assigned to only a limited number of protein families. Detailed knowledge about the characteristics of food allergens, their structures, biological activity, and stability, may be helpful in improving diagnosis of food allergy, avoiding unnecessary exclusion of diets, and assessing the risk of cross-reactive allergies to other food sources. The purpose of this review is to shed light on the sources and molecular properties of the allergenic proteins, their stability, the mechanisms of the allergenic responses, and recent findings related to prevention of this serious issue.
Food allergy occurs in 1.5% to 6% of the population. However, confirming the diagnosis of food allergic disorders is often difficult because of the lack of reliable, convenient testing and our incomplete understanding of the underlying pathophysiology. Several recent studies have expanded the knowledge regarding the pathophysiology and diagnosis of food allergy. Rodent models have elucidated several mechanisms of mast cell-mediated responses and antigen transport. Although it had been suggested that certain allergic disorders have a genetic predisposition, investigators are now identifying genomic mutations associated with specific atopic conditions in humans. A novel endoscopic method may provide insight into diagnosis, as well as pathophysiology of allergic disorders.
(C) 1998 Lippincott Williams & Wilkins, Inc.
Background:
Birch pollen is a major cause of pollinosis and is responsible for cross-reactive oral allergies to fruits, nuts, and vegetables. The major allergen, Bet v 1, has been extensively characterized, and 3 minor allergens, Bet v 2, Bet v 3, and Bet v 4, have been cloned and sequenced. Recently, another birch pollen protein with an apparent mass of 35 kd was described as a new IgE-binding protein in birch pollen with cross-reacting homologues in plant foods.
Objective:
The aim of this study was to determine the primary structure of the 35-kd birch pollen allergen and to investigate its immunologic properties.
Methods:
On the basis of a known complementary DNA fragment, a PCR strategy was applied to obtain the full-length nucleotide sequence of the coding region. The protein was expressed as His-Tag fusion protein in Escherichia coli and purified by Ni-chelate affinity chromatography. Nonfusion protein was obtained by cyanogen bromide treatment of the fusion protein. IgE-binding characteristics and potential allergenicity were investigated by immunoblot, immunoblot inhibition analysis, rat basophil leukemia-cell mediator release assay, and basophil histamine release and compared with those of natural (n) Bet v 5, recombinant (r)Bet v 1, and rBet v 2.
Results:
Recombinant Bet v 5 has a mass of 33 kd, an isoelectric point of 9.0, and sequence identity of 60% to 80% to isoflavone reductase homologue proteins from various plants. On immunoblots the recombinant Bet v 5 bound IgE from 9 (32%) of 28 sera from patients allergic to birch pollen with a CAP class of at least 3; Bet v 1 was detected by 89% of these patients. IgE immunoblot and inhibition experiments showed that nBet v 5 and rBet v 5 shared identical epitopes. A rabbit antiserum raised against pea isoflavone reductase and patients' IgE reacted with Bet v 5 and proteins of similar size in several vegetable foods, including exotic fruits. A similar reaction pattern was obtained with 2 Bet v 5-specific mAbs. Furthermore, Bet v 5 triggered a dose-dependent mediator release from rat basophil leukemia 2H3 cells passively sensitized with murine anti-birch pollen IgE and from basophils of a Bet v 5-reactive subject with birch pollen allergy. In contrast, no mediator release could be induced from basophils of a subject who was monosensitized to Bet v 1.
Conclusions:
This 33-kd protein, designated as Bet v 5, is a new minor allergen in birch pollen and may be responsible for pollen-related oral allergy to specific foods in a minority of patients with birch pollen allergy. Amino acid sequence comparison and immunoreactivity to anti-isoflavone reductase serum indicate that Bet v 5 is related to isoflavone reductase, a protein family that is involved in plant defense reactions.
Food hypersensitivity affects children and adults with an increasing prevalence, and is therefore an important public health problem in the majority of developed countries. Moreover, self-reported reactions to food are of several times higher prevalence, compared to hypersensitivity diagnosed following well established evidence-based diagnostic guidelines. In children, allergic food reactions are more common compared to non-allergic food hypersensitivity reactions, and 90% of them are caused with only 8 food allergens: cow's milk, soya, egg, fish, shellfish, peanut, tree-nuts and gluten. Diagnosis should be based on challenge tests with the potentially offending food allergens. Concerning other, more conservative diagnostic procedures, negative serology and negative skin-prick tests can exclude IgE-mediated food allergy, but positive tests, due to high rate of false positive reactions are not sufficient for diagnosis. Strict dietary avoidance of incriminated allergens is the only well established management strategy. However, this should be applied only if food allergy is well documented - following the exposition tests. Introducing elimination diet in a paediatric population, particularly with the elimination of multiple foods, could cause inappropriate growth and disturb organ maturation. Concerning allergy prevention, avoidance of allergens is not efficacious either during pregnancy and lactation or weaning period, and is therefore, not recommended neither as a population preventive measure, nor in children at risk.
Allergy to chickpea or Garbanzo bean (Cicer arietinum) has been reported in the Indian population. Little information is found regarding allergenic events involved in the chickpea allergy; therefore, chickpea allergenicity assessment was undertaken. In vivo and ex vivo studies were carried out using BALB/c mice. Chickpea skin prick test positive patients have been used to extend this study in humans. Identification of allergens was carried out by simulated gastric fluids assay for pepsin resistant polypeptides and validated by IgE western blotting using chickpea sensitive humans and sensitized mice sera. Our data have shown the occurrence of a systemic anaphylactic reaction resulting in reduced body temperature after challenge along with significantly increased levels of IgE, IgG1, MMCP-1, CCL-2 as well as histamine. Further, increased Th1/Th2 (mixed) cytokine response was observed in spleen cell culture supernatants. Jejunum, lungs and spleen showed prominent histopathological changes specific for allergic inflammation. Immunoblotting with pooled sera of either sensitized mice or human sera recognized seven similar IgE binding polypeptides that may be responsible for chickpea induced hypersensitivity reactions. This study has addressed the allergenic manifestations associated with chickpea consumption and identifies the proteins responsible for allergenicity which may prove useful in diagnosis and management of allergenicity of legumes especially chickpea.
Adverse reactions to foods are classified according to the presence or absence of involvement of the immune system, which may or may not include the production of immunoglobulin E (IgE) antibodies. This review focuses on the epidemiology, diagnosis, and management of adverse food reactions, primarily in adults, and excluding celiac disease and lactose intolerance. Reported reactions to foods are often believed to be manifestations of a food allergy; however, IgE-mediated food allergy only affects 1% to 4% of adults, with seafood, tree nuts, peanuts, fruits, and vegetables being the most common triggers. Diagnosis is challenging and most commonly achieved through careful evaluation of clinical history followed by elimination and reintroduction or challenge with the suspected offending food. With acute-onset allergic reactions, estimation of food-specific IgE antibodies is frequently used to confirm or refute the diagnosis. Recent developments, such as single allergen assays, enhance the diagnosis of IgE-mediated food allergy, but the gold standard remains oral food challenge. Despite recent advances in the management of food allergy, including the promotion of oral tolerance, the mainstay of management is still the avoidance of food triggers. Dietary management can be compromised by nutritional inadequacy, accidental exposure, food labeling, and quality of life or adherence issues. It is essential that adults with confirmed food allergy receive optimal nutrition and dietetic support to enable them to manage their condition.
Food allergy is among the most common of the allergic disorders, with a prevalence of 6-8 per cent in children up to the age of three. However, many people self-diagnose, putting their children at risk of malnutrition, possibly as a result of lack of awareness by health professionals of food allergy as a potential cause of conditions such as infantile eczema, chronic diarrhoea, faltering growth and gastrooesophageal reflux. NICE (The National Institute for Health and Clinical Excellence) recently published guidelines, which they hope will help to improve the diagnosis of food allergies within the community. If food allergy or lactose intolerance is suspected, the mainstay of a diagnostic work up should comprise of a detailed allergy-focused clinical history, part of which will involve determining whether the adverse reaction is typically an immediate (IgE mediated) or more delayed-type (non-IgE mediated) allergic reaction, or whether it may be lactose intolerance; a form of non-allergic hypersensitivity.
One of the major soybean allergens, Gly m Bd 28K, is suggested to be biosynthesized as a preproprotein form, which would be composed of a signal peptide, Gly m Bd 28K and the C-terminal peptide (the 23-kDa peptide). However, the 23-kDa peptide has never been characterized. In the present study, we prepared a monoclonal antibody (mAb) against a recombinant 23-kDa peptide expressed in Escherichia coli to detect the 23-kDa peptide in soybean. Several proteins were detected by immunoblotting with the mAb. All of the proteins were shown to have the identical N-terminal amino acid sequence, suggesting that the proteins correspond to the C-terminal part of the Gly m Bd 28K precursor. Furthermore, Gly m Bd 28K and the 23-kDa peptide were observed to come out at the 21st day after flowering and to locate in the crystalloid part of protein storage vacuoles in growing cotyledons. Some of the 23-kDa peptides were shown to be glycoproteins with an N-linked glycan moiety and exhibited the binding to IgE antibodies in the sera of patients sensitive to soybean. The binding of the peptides to IgE antibodies was suggested to be predominantly dependent on their glycan moiety. This study proves the occurrence of the 23-kDa peptide in soybean and that it is a new allergen.
The present investigation was undertaken to obtain molecular data of a new immunoglobulin (Ig)E-binding birch pollen protein with a mass of 35 kDa. In a previous study, this protein showed IgE cross-reactivity with 34- and 35-kDa proteins in apples, pears, carrots, bananas and other exotic fruits. Since the protein was N-terminally blocked, it was purified by preparative SDS-PAGE, and multiple proteolytic fragments were subsequently generated by in-gel digestion with the endoproteinases Glu C, Lys C and Clostripain. After electrophoretic separation and blotting onto polyvinylidene difluoride (PVDF), the resulting polypeptides were subjected to N-terminal amino acid microsequencing. The internal sequences obtained showed a high degree of sequence identity to isoflavone reductases (IFR) and isoflavone reductase-like proteins (IRL) from several plants which also had a similar size. For a stretch of 25 consecutive residues this identity ranged from 56% for IFR from peas and chick peas and an IRL from maize, to 80% for a tobacco IRL. A 453 bp fragment was amplified from total birch pollen RNA by polymerase chain reaction (PCR) using primers derived from the nucleotide sequence of the tobacco IRL. The deduced 151 amino acid sequence represented approximately 50% of the protein and confirmed the sequence identities obtained by Edman degradation. Moreover, the 25 amino acid sequence was included in the cloned fragment. Deduced and determined amino acids showed only one mismatch, which was due to a single nucleotide exchange. At the antibody level, the immunological relationship of the birch pollen protein to IRL and IFR was demonstrated by immunoblotting with a rabbit antiserum against a pea IFR which recognized the same birch protein as patients' IgE. The rabbit antiserum also reproduced the cross-reactivity pattern previously observed with patients' IgE by recognizing related proteins in specific plant foods, including some exotic fruits. We therefore suggest that the 35-kDa birch pollen protein belongs to the IFR/IRL family and represents a minor allergen, possibly being responsible for less common pollen-related food allergies in patients allergic to birch pollen.
The specific IgE binding by protein extracts of 11 food legumes, including soybean, was examined by RAST and RAST inhibition. Sera from 15 peanut-sensitive patients were, with very few exceptions, positive in the RAST to all the legumes. RAST-inhibition testing of each extract against RAST discs of the other legumes indicated considerable cross-reactivity of IgE binding between the legumes. Cross-allergenicity was demonstrated to be most marked between the extracts of peanut, garden pea, chick pea, and soybean. The results have important implications for selection of effective hypoallergenic diets and for the diagnosis of patients hypersensitive to foods.
No systematic study on allergenicity of green gram seed proteins have been performed so far, although incidences of IgE-mediated reaction to green gram seedlings have been reported.
We sought to investigate the allergenic potential of green gram, followed by identification and characterization of its relevant allergens using proteomic approaches.
BALB/c mice were sensitized intraperitoneally with green gram proteins, and levels of specific Igs, Th2 cytokines, histamine, anaphylactic symptoms and histopathological responses were studied. Twelve naso-bronchial allergic patients with a history of sensitization to green gram were selected on the basis of positive skin prick test and elevated specific IgE levels. Green gram allergens were identified and characterized by their ability to endure pepsin, by IgE immunoblot of two-dimensional (2D) gels in combination with mass spectrometry and by bioinformatics approaches.
Increased specific IgE, IgG1, Th2 cytokine and histamine levels, high anaphylactic scores and histological changes in lungs and spleen of green gram crude protein extract-treated mice are indicative of its sensitization ability. Four proteins (molecular weights: 52, 50, 30 and 18 kDa) showed pepsin resistance and IgE-binding capability with sensitized human and mice sera. The four proteins tentatively named as Vig r2 (52 kDa, pI 5.7), Vig r3 (50 kDa, pI 5.8), Vig r4 (30 kDa, pI 6.6) and Vig r5 (18 kDa, pI 5.5) showed significant sequence similarity with known allergens of soybean, lentil, pea, lupin, etc. Mass spectrometric analysis identified Vig r2 as 8S globulin β-isoform precursor, Vig r3 as 8S globulin α-isoform precursor and Vig r4 as seed albumin.
Green gram seeds contain at least four clinically relevant allergenic proteins, namely Vig r2, Vig r3, Vig r4 and Vig r5 that were capable of inducing strong IgE-mediated reactions. One of the most important steps towards diagnostic and therapeutic approaches to deal effectively with food allergy is continued identification of newer food allergens and their characterization. The significance of this study can be enormous as the data generated may work as basic biology data in developing a green gram species modified genetically that may have reduced allergenicity.
We sought to assess the allergenic potential of red gram by identifying and characterizing the responsible proteins. Immunoblotting was performed to detect IgE binding proteins. Identities of these proteins were confirmed by mass spectrometry. To evaluate allergenic potential, BALB/c mice were sensitized with red gram proteins and levels of specific immunoglobulins, histamine, Th2 cytokines were measured. Allergenic response was evident by significant increase in specific IgE, IgG1, histamine and Th2 cytokine levels. Prominent anaphylactic symptoms, discernible histopathological responses and down regulation of IFN-gamma levels give strong support towards allergenicity of red gram proteins. IgE immunoblot detected five proteins; one of 66 kDa, three of 45 kDa (pI of approximately 5.3, 5.9 and 6.6) and one of 30 kDa. All these proteins showed homology to known allergens of soybean (different subunits of beta-conglycinin), lentil (Len c1 and Len c2), peanut (Ara h1) and pea (vicilin). In conclusion, five novel IgE binding proteins (namely Caj c1, Caj c2, Caj c3, Caj c4 and Caj c5) were identified as putative clinically relevant allergens.
Green bean (GB) has been reported to cause allergic reactions after ingestion, contact or inhalation of particles deriving from processing or cooking. Up-to-date no food allergens have been fully characterized in GB.
To characterize the GB major allergen(s) on a molecular level and to verify the involvement of non-specific lipid transfer proteins (nsLTPs) in GB allergy.
We recruited 10 Spanish patients reporting adverse reactions to GB. Skin prick tests, specific IgE detection and oral provocation were performed. Two nsLTP cDNAs were cloned from GB and over-expressed in Pichia pastoris. The recombinant LTPs (rLTPs) were characterized by circular dichroism spectroscopy and IgE-binding assays (immunoblotting and ELISA) with the patients' sera. Three natural LTPs (nLTPs) were further purified from GB fruit by chromatography. In vitro histamine release test was applied to compare the allergenic potency of rLTPs and nLTPs.
Oral provocation test confirmed GB allergy. A 10kDa protein in GB extract was recognized by 80% of the sera and identified as nsLTP. The two rLTPs (named LTP1a and LTP1b), share 61.3% aa identity and present the typical nsLTP-like secondary structure. The IgE-binding and histamine release assays provided evidence that rLTPs and nLTPs possess different allergenic potency.
nsLTP (Pha v 3) is the major allergen in GB and constitute a potential risk for patients affected by LTP-syndrome. GB encodes for several LTPs with different immune reactivity.
In the last years, legume proteins are gaining importance as food ingredients because of their nutraceutical properties. However, legumes are also considered relevant in the development of food allergies through ingestion. Peanuts and soybeans are important food allergens in Western countries, while lentil and chickpea allergy are more relevant in the Mediterranean area. Information about the effects of thermal-processing procedures at various temperatures and conditions is scarce; therefore, the effect of these procedures on legume allergenic properties is not defined so far. The SDS-PAGE and IgE-immunoblotting patterns of chickpeas and lentils were analyzed before and after boiling (up to 60 min) and autoclaving (1.2 and 2.6 atm, up to 30 min). The results indicated that some of these treatments reduce IgE binding to lentil and chickpea, the most important being harsh autoclaving. However, several extremely resistant immunoreactive proteins still remained in these legumes even after this extreme treatment.
Lupin, a legume with good nutritional value, is used in food production today, most often in bakery products. Lupin sensitization is often seen among patients with reactions to legumes, but the number of reports describing lupin anaphylaxis is also increasing.
To investigate the occurrence of lupin sensitization, cross-reactivity, and lupin allergy among patients with suspected food allergy in Finland, where lupin is a labeled ingredient in few products.
The occurrence of positive skin prick test (SPT) reactions to lupin seed flour was studied among 1522 patients with suspected food allergy from November 1, 2005, through December 31, 2007. Clinical histories and diagnostic SPT results were analyzed among patients with positive SPT results to lupin. For 1 patient, ImmunoSpot and lupin radioallergosorbent test inhibition methods were used.
Lupin sensitization was shown in 25 of 1522 patients (1.6%), and probable lupin allergy was diagnosed in 7 of 25 patients, in whom the clinical symptoms varied from anaphylaxis and respiratory symptoms to contact urticaria and itchy mouth. Cross-reactions or concurrent reactions to other legumes were seen in 18 of 25 patients.
Clinically relevant lupin allergy often occurs in patients without atopic background or other food allergies, although lupin sensitization most commonly seems to represent cross-reactivity to other legumes. The occurrence of lupin allergy in a country where lupin has not been traditionally used is surprisingly common, suggesting that short-term use of modest amounts of lupin can cause serious allergic reactions.
Leguminous crops are the main source of protein in Asian subcontinent including India and their proteins may induce allergic reactions in sensitized individuals. Pepsin resistance of proteins is a characteristic feature of most of the allergens. Simulated gastric fluid (SGF) assay as validated by digestion of purified known allergenic and non-allergenic proteins was the basis of this study. Purified allergenic proteins were stable to SGF digestion contrary to rapidly digested non-allergenic proteins. Crude proteins extracts (CPE) of soybean, peanut, chickpea, black gram, kidney bean and Bengal gram were digested in vitro to detect their non-digestible proteins. Six proteins from soybean and seven from peanut remained undigested after SGF digestion. Likewise, seven proteins from chickpea (70, 64, 55, 45, 35, 20 and 18 kDa), ten from black gram (47, 30, 29, 28, 26, 24, 22, 16, 14 and 12 kDa), five from kidney bean (45, 29, 24, 20 and 6.5 kDa) and one from Bengal gram (20 kDa) remained undigested in SGF. Most of the proteins stable in SGF for more than 2 min showed similarity with characterized allergens on the basis of their molecular weights as in case of soybean, peanut, chickpea and black gram. Also, soybean and chickpea stable proteins showed IgE binding property with respective allergic patient's sera. The non-digestible proteins from the chickpea, black gram, kidney bean and Bengal gram are being reported for the first time by our group. IgE binding of SGF resistant soybean and chickpea proteins is being reported first time as well.
To determine the prevalence of sensitization to lupin flour in patients consulting allergists, in order to evaluate the risk of primary and secondary allergies to lupin.
A prospective study carried out by members of the Allergy Vigilance Network, using prick-tests with a commercial lupin flour extract in patients with various allergic symptoms. The study design classified patients into four groups: peanut allergy, current atopic disease, latent atopy, no atopy. Data were collected and analysed by Network coordinators.
Over a two-month period, 88 French and Belgian allergists tested 5,366 patients: 2,680 children and 2,686 adults aged over 16 years. Of the 2,680 children, 11.15% presented with peanut allergy. The frequency of cross-reactivity with lupin was 17.1% for patients with peanut allergy, 2.5% for children with current atopic disease and 1.7% for healthy children with latent atopy. In the 2,686 adults, peanut allergy was diagnosed in 1.86% of patients with cross-reactivity to lupin in 14.6%. Sensitization to lupin was detected in 3.7% of patients with current atopic disease and in 1.8% of those with latent atopy.
The relative frequency of latent sensitisation to lupin in patients of all ages presenting with atopic disease is a new factor indicating the likelihood of an increase in primary food allergies to lupin flour. This justifies the recent decision requiring mandatory labelling of lupin, and shows the need to inform consumers who may be unaware that this ingredient is being used increasingly. Sensitization to lupin should be searched by prick-tests in any case of peanut allergy. Prick-test to lupin may be valuable whenever a food allergy is suspected when no current food allergens have been identified.
The prevalence of food allergy has increased dramatically in recent years. Tremendous research progress has been made in understanding the pathophysiological mechanisms of allergy and in identifying and characterizing food allergens. Peanut is a major food allergen source and Ara h 3 is a major peanut allergen. Using overlapping short peptides, several linear IgE-binding epitopes in Ara h 3 have been defined before. However, the structure of Ara h 3 of the native allergen is not clear and information on conformational epitopes is lacking. Structural characterization of allergens is required for understanding the allergenicity of food allergens and for the development of immunotherapeutic agents. Previously, we have reported the crystallization of Ara h 3 purified from raw peanut. Here we report the crystal structure of Ara h 3 at 1.73A resolution. Mapping of the previously defined linear epitopes on the crystal structure of Ara h 3 indicated that linear epitopes with more solvent exposure were those indicated by the literature to react with more patient sera. The structure of Ara h 3 may be used to assess the importance of conformational epitopes in further investigations.
Allergy type sensitization occurring in the gut results from a break in oral tolerance, mostly occurring in early childhood. In these patients, a minute amount of the large load of potential food allergens not only will result in immunoglobulin E (IgE) type sensitization mostly, but also in food allergies resulting from other mechanisms including eosinophil-driven disease or resulting from T-cell-mediated inflammation. Symptoms elicited by subsequent exposure to foods in these patients will be mostly in relation to the mechanism of the disease. In this educational review series, we described three cases of food allergy, first, a child with typical IgE-mediated food allergy, second, a child with eosinophilic proctocolitis and in the third patient, we will address tolerance acquisition mechanisms. These cases are discussed with regards to their specific immune events.
The use of lupine in food has been increasing during the last decade and allergic reactions to lupine have been reported, especially in peanut-allergic patients. The frequency and the degree of cross-reactivity to other legumes are not known. The aim of the study was to investigate the frequency of sensitization to lupine, and in addition to pea and soy, and its clinical relevance, in peanut-sensitized patients. Furthermore, to determine the eliciting dose (ED) for lupine using double-blind placebo-controlled food challenges (DBPCFC).
Thirty-nine unselected peanut-sensitized patients were evaluated by skin prick tests (SPT) and ImmunoCAP to lupine, pea, and soy. Clinical reactivity was measured by DBPCFC for lupine, and by history for pea and soy.
Eighty-two percent of the study population was sensitized to lupine, 55% to pea, and 87% to soy. Clinically relevant sensitization to lupine, pea, or soy occurred in 35%, 29%, and 33% respectively of the study population. None of the patients was aware of the use of lupine in food. The lowest ED for lupine, inducing mild subjective symptoms, was 0.5 mg, and the no observed adverse effect level (NOAEL) was 0.1 mg. No predictive factors for lupine allergy were found.
In peanut-sensitized patients, clinically relevant sensitization to either lupine or to pea or soy occurs frequently. The ED for lupine is low (0.5 mg), which is only fivefold higher than for peanut. Patients are not aware of lupine allergy and the presence of lupine in food, indicating that education is important to build awareness.
P>This issue of Pediatric Annals focuses on the topic of food allergy in children. We have chosen this topic because food allergy is receiving more attention, both in the medical literature and in the mainstream press. In fact, earlier this year, the American Academy of Pediatrics published new guidelines concerning diet and development of atopic diseases. Web sites, newspapers, and other periodicals also have frequently featured personal stories about food allergies. Because of these phenomena, it is highly likely that parents will pose the question, “Does my child have a food allergy?” or “What can I feed my child?” to pediatric primary care providers before they seek consultation with an allergist/immunologist. Given the expanding amount of research, as well as current gaps in understanding of food allergy, this issue of Pediatric Annals targets key areas to help pediatricians with recognition and management.
ABOUT THE GUEST EDITOR
Jacqueline A. Pongracic, MD, is Associate Professor of Pediatrics and Medicine at Northwestern University’s Feinberg School of Medicine. Since 2004, she has also served as Division Head of Allergy and Immunology at Children’s Memorial Hospital in Chicago.
Dr. Pongracic completed her training in Allergy and Immunology at Johns Hopkins University. It was at that time, while working with Drs. Hugh Sampson and Robert Wood, that she developed an interest in food allergy. Since joining the medical staff at Children’s Memorial Hospital in 1991, Dr. Pongracic has focused on food allergy, developing clinical, educational, and collaborative research programs, as well as community-based programs for advocacy and education.</P
Preseasonal local nasal immunotherapy (LNIT) by means of an extract in macronized powder form has been studied in allergic rhinitis to parietaria. Twenty-four Parietaria-sensitive patients have been studied for 18 weeks in a double-blind controlled trial. Subjects were selected on the basis of a positive skin test, RAST and intranasal challenge to Parietaria antigen. Three eight-patient groups were randomly planned: the first group was given native Parietaria product, the second modified Parietaria product, and the third placebo. During the pollen season no difference was observed in mean weekly symptom score between the three groups, while the mean weekly medication score was significantly lower in the treated groups than the control group. Only the treated groups showed a significant increase in specific nasal threshold to Parietaria after treatment. Adverse reactions to LNIT, limited to the upper respiratory tract, occurred rarely and did not interfere with the dose schedule. This study indicates that LNIT in powder form may be a suitable alternative to the traditional subcutaneous immunotherapy in terms of clinical efficacy and safety.
Peanuts are frequently a cause of food hypersensitivity reactions in children. Serum from nine patients with atopic dermatitis and a positive double-blind, placebo-controlled, food challenge to peanut were used in the process of identification and purification of the peanut allergens. Identification of a second major peanut allergen was accomplished with use of various biochemical and molecular techniques. Anion exchange chromatography of the crude peanut extract produced several fractions that bound IgE from the serum of the patient pool with positive challenges. By measuring antipeanut specific IgE and by IgE-specific immunoblotting we have identified an allergic component that has two closely migrating bands with a mean molecular weight of 17 kd. Two-dimensional gel electrophoresis of this fraction revealed it to have a mean isoelectric point of 5.2. According to allergen nomenclature of the IUIS Subcommittee for Allergen Nomenclature this allergen is designated, Ara h II (Arachis hypogaea).
Martin JA, Compaired JA, dc la Hoz B, Quirce S, Alonso MD, Igca JM, Losada E. Bronchial asthma induced by chick pea and lentil.
Allergic reactions to legumes through inhalation have rarely been described. We report the case of a 20-year-old man who experienced asthmatic attacks when exposed to the steam from cooking either chick pea or lentil. Type I hypersensitivity to the antigens in these legumes was demonstrated by means of immediate skin reactivity, histamine release tests, RAST and RAST inhibition. Specific bronchial challenges with the heated (75° for 30 min) extracts of chick pea and lentil elicited isolated immediate responses.
Proteins responsible for respiratory allergy to soybean have been purified from an extract of soybean hulls. The purification procedure combined size exclusion and reverse-phase HPLC. Two pure glycoproteins (S1 and S2) exhibiting IgE-binding ability, as demonstrated by immunoblotting and ELISA techniques, were obtained. Both proteins displayed low molecular weight values on SDS-PAGE (S1, 7.0 kD; S2 7.5 kD). Protein S1 showed charge microheterogeneity, rendering two bands at pH 6.1-6.2 on IEF, whereas S2 showed a single band at pH 6.8. Amino acid composition analyses revealed a strong homology between S1 and S2 and, as a characteristic feature, a high percentage of hydrophobic residues, mainly leucine and isoleucine. Concerning the allergenic activity, both proteins were recognized by the specific IgE from 95% of patients who suffered asthma attacks during the asthma outbreaks of 1987 and 1988 in Cartagena (Spain), caused by soybean dust. Besides, proteins S1 and S2 were able to, separately, inhibit up to 75% the binding of specific IgE to the whole extract. Moreover, purified proteins totally crossreacted, even though protein S2 seemed to be slightly more active in all the immunochemical techniques employed. Results presented allow us to conclude that both proteins are isoallergens and to name them as Gly m IA (protein S2) and Gly m IB (protein S1), according to the IUIS-allergen nomenclature system.
The IgE-binding proteins in soybeans were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the fractionated soybean proteins probed with the sera of the patients with atopic dermatitis. About 20% of the patients examined were shown to have specific IgE antibodies to soybean proteins. At least 16 soybean proteins with molecular weights ranging from about 70,000 to 14,000 were recognized by the sera of the patients: 10 major IgE-binding components were found in the 7S-globulin fraction, and the others mainly in the 2S-globulin and whey fractions. The IgE antibodies of the patients bound most strongly and frequently to a unique protein with molecular weight of about 30,000 in the 7S-globulin fraction, which appeared to be the major allergen in soybeans and was named as Gly m Bd 30 K. The proteins in the 11S-globulin fraction were scarcely recognized by the patients' sera and assumed to be less allergenic for the patients with atopic dermatitis.