Diagnosis and therapy of food allergy

According to the recently revised nomenclature for allergy the term "Food Hypersensitivity" is proposed to define a reaction on food exposure causing objectively reproducible symptoms or signs at a dose tolerated by normal subjects. Those reactions to food in which immunologic mechanisms are demonstrated comprise the term "Food Allergy". Immunologic reactions to food in which an immunoglobulin E (IgE)-mediated mechanism is established are defined as IgE-mediated food allergy. This review focuses on IgE-mediated allergic reactions to foods.     

T lymphocytes and food allergy

Food allergy is a hypersensitivity reaction to normally harmless substances and involves humoral immune responses, mediated by immunoglobulin (IgE) synthesized by B lymphocytes, and cellular immune responses mediated by T lymphocytes. An IgE-mediated mechanism leads to clinical symptoms occurring immediately after food ingestion, e. g., "the oral allergy syndrome". For delayed reactions involving the gastrointestinal tract or the skin, the underlying immune mechanisms are less clear. In order to elucidate the cellular response to food allergens, human allergen-specific T cell cultures generated in vitro represent helpful tools. The majority of food allergen-specific CD4(+) T lymphocytes isolated from food-allergic individuals was found to synthesize high levels of IL-4 and IL-13, two cytokines required for initiation of IgE synthesis. Due to selective homing profiles, food-specific T cells seem also to be involved in defining the target organ of the allergic inflammation. Recent data provide evidence that in addition to IgE-mediated inflammation, food allergen-specific T lymphocytes may also cause inflammatory responses independently of IgE-mediated mechanisms.     

牛乳蛋白过敏综述

牛乳过敏(CMA)是一种复杂的无序状态。许多牛乳蛋白均可引起过敏。牛乳蛋白过敏受多种免疫机制驱动。过敏发生率和占主导地位的过敏机制随年龄改变,一般婴儿中易发生IgE介导型过敏,成人过敏多为非IgE介导。CMA真实患者或疑似患者及早避食乳制品和及时给予喂养指导十分重要。本文通过目前对过敏的诱发和免疫机理的了解探讨CMA的流行病学和自然进程。并对过敏反应的初级和次级预防的策略及正在进行的有效彻底治愈CMA的研究进行分析。     

The pathophysiology of ocular allergy: A review

Allergic eye disease is an abnormal immune hypersensitivity response to allergens. It is characterized by IgE-mediated and/or T-lymphocyte-mediated immune hypersensitivity reactions that lead to an immune response, resulting in the clinical manifestations of ocular allergy. This review will focus on immunopathophysiology of the different types of allergic eye disease commonly encountered in the primary care setting. The objective is to provide the clinician with a considerable understanding of the immunopathogenesis of allergic eye disease. The primary focus of this review will be on the antibody- and cell-mediated immune hypersensitivity reactions relevant to allergic eye disease, the different phases of ocular allergic immune response and the histopathological manifestations of these commonly encountered ocular allergies. The basic concepts of immunology with emphasis on adaptive immunity and lymphocyte activation, as well as the components of the immune system that are relevant to ocular allergy will also be reviewed.     

食用小麦后运动诱发过敏反应的研究进展

食用小麦后运动诱发的过敏反应(WDEIA)是一种罕见的,但可能是严重的由IgE介导的食物过敏.单独摄入小麦并不会引起任何症状.然而,当摄入小麦后伴随运动、服用非甾体抗炎药、摄入乙醇时,将引发瘙痒、荨麻疹、血管性水肿、呼吸困难、低血压等过敏反应症状,严重者可致过敏性休克.为避免严重过敏反应,及时准确诊断尤为重要.然而由于...     

Impact of food processing on the structural and allergenic properties of egg white

BackgroundEgg is one of the most nutritious foods that is easily available and it has become a favorite source of major nutrients like lipids and proteins around the world. However, eggs can trigger severe allergic reactions, especially in infants and children. The reactions are mostly IgE-mediated with a range of symptoms related to nose and throat and further can lead to life-threatening anaphylaxis. A total of ten allergens have been recognized to date and researchers are actively working on understanding their structure-function relationship which could help reduce the allergy incidences. Major egg allergens are abundant in egg white which include ovalbumin (OA), ovomucoid (OVM), ovotransferrin (OVT) and lysozyme (Lys). In addition to allergens, avidin present in egg white is also extensively studied due to its anti-nutritional properties. Avidin is known to form a complex with biotin which makes it unavailable for absorption.Scope and approachThis review focuses on the effects of thermal and non-thermal processing methods on the structure and functional properties of various egg proteins including a wide range of allergens and anti-nutrients.Key findings and conclusionsNovel processing techniques including various non-thermal techniques show promising results in reducing the allergic reactions of egg. Anti-nutrients like avidin can be partly inactivated under combined high-pressure processing and heat treatment.     

浅析食源性低聚肽的致敏风险

食源性低聚肽是以食用蛋白为原料水解的产物,分子质量小于1000 u,一般由2~10个氨基酸构成,可不需消化或稍加消化即可吸收,吸收利用率较高。食源性低聚肽具有一些生理活性功能,如抗氧化、抗菌,抑制血管紧张素转换酶活性等。近年来,食源性低聚肽被广泛应用于食品、保健品及化妆品等行业。从理论上来说,一般形成抗原表位至少需要5个氨基酸,由2~10个氨基酸组成的食源性低聚肽能够形成抗原表位而存在IgE介导过敏的潜在风险。据此,本文对可能引起食源性低聚肽致敏风险的因素,如存在抗原表位和可能发生交叉过敏反应进行分析,并对可能用于评价食源性低聚肽致敏性的方法进行介绍,对如何降低食源性低聚肽致敏风险的加工方法进行探讨,为食源性低聚肽的更广泛应用提供理论基础。     

Wheat Allergy and Intolerence; Recent Updates and Perspectives

The current review paper highlights the complicacies associated with communities relying on wheat as their dietary staple. Although, wheat is an important source of nutrients but is also linked with allergenic responses in genetically susceptible subjects. The wheat proteins especially α-amylase inhibitors, ω-5 gliadins, prolamins, nonprolamin, glucoprotein, and profilins are of significance importance. The allergenic responses are further categorized into IgE-mediated and non-IgE-mediated reactions. Conjugation and degranulation of the IgEs with the allergens results in release of several mediators. In contrary, non-IgE-mediated wheat allergy depends on immune complexes formed by food and food antibodies and cell-mediated immunity. As results, different diseases tend to occur on the completion of these reactions, i.e., celiac disease, baker's asthma, diarrhea, atopic dermatitis, and urticaria. This instant paper highlighted the concept of food allergy with special reference to wheat. The models are developed that are included in this paper showing the wheat allergen, their possible routes, impact on human health, and indeed possible remedies. The paper would provide the basic information for the researchers, common man, and allied stakeholders to cater the issue in details. However, the issue needs the attention of the researchers as there is a need to clarify the issues of wheat allergy and wheat intolerance.     

Bos d 13, A Novel Heat-Stable Beef Allergen

Scope

Red meat, a staple food of Western diets, can also induce IgE-mediated allergic reactions. Yet, apart from the heat-labile protein serum albumin and the carbohydrate α-Gal, the molecules causing allergic reactions to red meat remain unknown.

Methods and results

IgE reactivity profiles of beef-sensitized individuals are analyzed by IgE-immunoblotting with protein extracts from raw and cooked beef. Two IgE-reactive proteins are identified by peptide mass fingerprinting as myosinlight chain 1 (MYL1) and myosin light chain 3 (MYL3) in cooked beef extract and are designated Bos d 13 isoallergens. MYL1 and MYL3 are produced recombinantly in Escherichia coli. ELISAs proved their IgE reactivity and circular dichroism analysis showed that they represent folded molecules with remarkable thermal stability. In vitro gastrointestinal digestion experiments showed the higher stability of rMYL1 as compared to rMYL3. Exposure of a monolayer of Caco–2 cells to rMYL1 indicated that the molecule is able to cross intestinal epithelial cells without disturbing the integrity of the tight junctions, suggesting the sensitizing capacity of MYL1.

Conclusion

MYLs are identified as novel heat-stable bovine meat allergens.     

基于RBL-2H3模型分析过敏反应效应细胞激活的差异基因

构建IgE介导的大鼠嗜碱性粒细胞（rat basophilic leukemia，RBL）-2H3作为过敏反应细胞模型，并利用转录组测序分析比较RBL-2H3细胞激活前后的转录组基因差异，富集相关信号通路。IgE介导的RBL-2H3细胞激活后，过敏介质和细胞因子分泌显著提高；转录组测序得到RBL-2H3细胞激活前后的232 个差异表达基因，其中有127 个（54.74%）可进行基因功能注释；RBL-2H3细胞激活主要影响肿瘤坏死因子、丝裂原活化蛋白激酶、Janus激酶-信号转导与转录激活子、Toll样受体等信号通路，涉及的转录因子有MAP3K8、Nfkbia、Junb、Jun、Fos等。本研究建立了IgE介导的过敏反应体外细胞模型，并且通过对效应细胞转录组信息的全面分析和潜在靶点及信号通路的富集为过敏性疾病的防控治疗提供参考。     

Pistachio nut allergy: An updated overview

Pistachio nut (Pistacia vera) is highly appreciated for its organoleptic characteristics and potential health benefits. However, this tree nut is also responsible for triggering moderate to severe IgE-mediated reactions in allergic individuals. Currently, pistachio nut allergy has gained some special attention, mainly due to its intrinsic relation with cashew nut allergy. Like for other nuts, the prevalence of pistachio nut allergy seems to be increasing at a global scale. Until now, there are five allergenic proteins officially listed for pistachio nut (Pis v 1, Pis v 2, Pis v 3, Pis v 4 and Pis v 5). Relevant data on their biochemical classification has become available, enabling establishing a correlation with the respective clinical symptoms. The establishment of an effective allergen risk assessment is a key issue for the food industry, policy makers and regulatory agencies. Thus, the availability of fast, specific and sensitive methods to detect trace amounts of allergens in processed foods is crucial. In the specific case of pistachio nut, there are some protein- and DNA-based methods for its detection/quantification in foods, which can aid to verify label information. Accordingly, all relevant research advances on this topic were summarised, updated and critically discussed in this review.     

Anisakis Infection and Allergy in Humans

Compared with other well-studied parasitic diseases, fish-borne parasitic zoonoses do not get enough attention, especially because these zoonoses have been limited for the most part to populations living in low- and middle-income countries in Europe. Human fishery product-borne parasitic diseases caused by nematodes are the results of infection following ingestion of viable parasites, or as allergic reactions against parasite antigens. With the globalization of the seafood industry, the risk of humans acquiring anisakiasis in developed countries appears to be underestimated. For allergy, the only implicated parasite in fishery products is the nematode Anisakis simplex.     

Gluten-related disorders: Celiac disease,wheat allergy,and nonceliac gluten sensitivity

Abstract

The consumption of gluten-free products is becoming an increased alimentary habit in the general population. The scientific unfounded perception suggesting that the avoidance of gluten would improve health or that gluten could be toxic for humans are fostering medically unjustified adherences to a gluten-free diet. Currently, only patients diagnosed with celiac disease are advised to follow a strict lifelong gluten-free diet. In the same way, patients diagnosed with IgE-mediated wheat allergy must avoid exposure to wheat in any form. In that context, a third disorder, called nonceliac gluten sensitivity, characterized by distress after gluten consumption and in which neither celiac disease nor IgE-mediated allergy plays a role, has gained increased attention in the last years. Although important scientific advances have been made in the understanding of the pathologic mechanisms behind nonceliac gluten sensitivity, this disorder is still a matter of active debate in the scientific community. In the present review, the most recent advances in the immunopathology, diagnostic biomarkers and susceptibility determinants of gluten-related diseases are summarized and discussed. Furthermore, an updated overview of the new potential therapies that are currently underway for the treatment of gluten-related disorders is also provided.     

Mitigation of Major Peanut Allergens by Pulsed Ultraviolet Light

Peanut allergy represents one of the most severe IgE-mediated reactions with food, but to date, the only effective way to prevent peanut allergy is total avoidance. If allergens could be mitigated during food processing before a product reaches the consumer, this would substantially lessen the food allergy problem. The efficacy of pulsed ultraviolet light (PUV), a novel food processing technology, on reducing peanut allergens, was examined. This study revealed for the first time that PUV was also capable of deactivating Ara h 2, the most potent allergenic protein of peanut. Protein extracts from raw and roasted peanuts were treated for 2, 4, and 6?min and peanut butter slurry was treated for 1, 2, and 3?min in a Xenon Steripulse XL 3000? PUV system. The distance from the central axis of the lamp was varied at 10.8, 14.6, and 18.2?cm. The SDS?CPAGE showed a reduction in the protein band intensity for Ara h 1, Ara h 2, and Ara h 3 at the energy levels ranging from 111.6 to 223.2?J/cm². Reduction of the protein band intensity for peanut allergens increased with treatment time but decreased with increased distance from the PUV lamp. The ELISA for peanut extracts and peanut butter slurry showed a reduction in IgE binding of up to 12.9- and 6.7-folds, respectively, compared to control.     

Effects of Bacillus subtilis natto on performance and immune function of preweaning calves

The effects of Bacillus subtilis natto on performance and immune function of dairy calves during the preweaning phase were investigated in this study. Twelve Holstein male calves 7 ± 1 d of age were randomly allotted to 2 treatments of 6 calves. The Bacillus subtilis natto was mixed with milk and fed directly to the calves. The calves were weaned when their starter intake reached 2% of their weight. Blood was collected and IgA, IgE, IgG, IgM, and cytokine levels in the serum of all the calves were determined. The results showed that Bacillus subtilis natto increased general performance by improving the average daily gain and feed efficiency and advanced the weaning age of the calves. No difference was observed in serum IgE, IgA, and IgM, whereas serum IgG was higher in the Bacillus subtilis natto-supplemented calves than in the control calves. Furthermore, calves fed with Bacillus subtilis natto were found to secrete more IFN-γ, but tended to produce less IL-4 than did the control calves, although serum IL-6 and IL-10 were not affected. This study demonstrated that Bacillus subtilis natto did not stimulate IgE-mediated allergic reactions, but increased serum IgG and IFN-γ levels in the probiotic-fed calves. We propose that the viable probiotic characteristics of Bacillus subtilis natto benefit calf immune function.     

鲜切果蔬的品质及贮藏保鲜技术研究进展

鲜切果蔬的新鲜、健康、卫生和方便等特点使其在发达国家发展迅速,已成为果蔬采后研究的新领域。鲜切果蔬因经过清洗、去皮、切分等处理,产品的品质下降快、生理生化代谢加剧、易受微生物侵染,货架寿命缩短。本文简述了引起鲜切果蔬品质劣变的原因,并重点介绍了近年来国内外对鲜切果蔬贮藏保鲜技术研究的新进展,其中包括物理、化学、生物保鲜技术和综合保鲜技术,以期为今后更深入的研究提供借鉴与参考。     

水产品过敏原的研究现状和展望

水产品作为人类食物的重要来源之一,其市场和消费群体不断扩大。与此同时,由水产品引发的食物过敏也日益增多,在联合国粮农组织公布的八大类过敏食物中,水产品就占了两大类。水产品过敏原有小清蛋白(Parvalbumin)、鱼卵蛋白(如鲑鱼的硫酸鱼精蛋白)和胶原蛋白(Collagen)、原肌球蛋白(Tropomyosin,TM)、精氨酸激酶(Arginine kinase)、肌球蛋白轻链(Myosin light chain)、肌钙结合蛋白(Sarcoplasmic calcium binding pro-tein)、血蓝蛋白亚基(Hemocyanin subunits)等。基于此,本文重点概述了国内外水产品过敏原及其加工脱敏技术的研究现状,以及今后水产品过敏原研究的发展趋势。     

水产品过敏原及其消减方法研究进展

水产品在人类营养和健康中扮演重要角色。随着水产养殖业和国际贸易的发展,其市场和消费群体不断增多;由此水产品引发的过敏问题也逐渐增多,已成为世界性的重大食品安全问题之一。水产品的主要过敏原是小清蛋白(parvalbumin)和原肌球蛋白(tropomyosin,TM);另外,卵清蛋白、胶原蛋白(collagen)、精氨酸激酶(arginine kinase)、肌球蛋白轻链(myosin light chain)、肌钙结合蛋白(sarcoplasmic calcium binding pro-tein)等过敏原也扮演重要角色。基于此本文综述了水产品过敏原致敏机制、过敏原的种类、水产品致敏性的消减方法,并展望了水产品过敏原今后的研究方向和发展趋势。     

Impact of dietary factors and food processing on food allergy

Allergic reactions to food can significantly reduce the quality of life and even result in life‐threatening complications. In addition, the prevalence of food allergy has increased in the last decades in industrialized countries and the mechanisms underlying (increased) sensitization are still not fully understood. It is believed that the development and maintenance of oral tolerance to food antigens is a process actively mediated by the immune system and that this reaction is essential to inhibit sensitization. Ongoing research indicates that different dietary factors also may contribute to immune homeostasis and oral tolerance to food and that food processing modulates allergenicity. One of the major questions in food allergy research is therefore which impact nutrition and food processing may have on allergenicity of food and perhaps on sensitization. We summarize in this review the different dietary factors that are believed to contribute to induction of oral tolerance and discuss the underlying mechanisms. In addition, the functional consequences of allergen modification will be emphasized in the second part as severity of allergic reactions and perhaps sensitization to food is influenced by structural modifications of food allergens.     

食品过敏原标签要求及生产过程控制初探

食品过敏已成为世界关注的重大公共卫生学和食品安全问题。食品过敏原是引起食品过敏的直接诱因,具有耐加工和交叉反应的特性。国际食品法典委员会(Codex Alimentarius Commission,CAC)规定了必须在食品标签中标注的8种可能引起过敏反应的食品及其配料,包括含有麸质的谷类、甲壳动物及其制品、鸡蛋及其制品、鱼类及其制品、花生、大豆及其制品、奶和奶制品(包括乳糖)、坚果及其制品、浓度不低于10 mg/kg的亚硫酸盐。欧盟、美国、日本、澳大利亚和新西兰等已根据国际食品法典委员会对过敏原的要求出台强制性标识食品过敏原的法规,这在一定程度上对我国出口食品企业造成了影响。本文通过对比CAC以及欧盟、中国、美国、日本、澳大利亚和新西兰等地有关过敏原标签的要求,提醒出口食品加工企业减少因标签不合格造成的经济损失,并为其在生产加工过程中过敏原的控制提出建议。