IgG mediated food allergy

As of late, evidence has been emerging that the Maillard reaction (MR, also referred to as glycation) affects the structure and function of food proteins. MR induces the conformational and chemical modification of food proteins, not only on the level of IgG/IgE recognition, but also by increasing the interaction and recognition of these modified proteins by antigen-presenting cells (APCs). This affects their biological properties, including digestibility, bioavailability, immunogenicity, and ultimately their allergenicity...

Mounting evidence demonstrates that a high-salt diet (HSD) not only affects hemodynamic changes but also disrupts immune homeostasis. The T helper 17 (Th17) and regulatory T cells (Tregs) are susceptible to hypersalinity. However, research on the influence of sodium on Th2-mediated food allergies remains scarce. We aimed to investigate the effect of dietary sodium on the immune response to food allergies. Mice maintained on an HSD (4% NaCl), low-salt diet (LSD; 0.4% NaCl), or control diet (CTRL; 1.0% NaCl) were orally sensitized with ovalbumin (OVA) and a cholera toxin (CT) adjuvant, and then subjected to an intragastric OVA challenge...

Anaphylaxis is an acute, potentially life-threatening systemic hypersensitivity reaction. Classically, anaphylaxis is an immunoglobulin (Ig) E-mediated reaction; however, IgG or immune complex complement-related immunologic reactions that lead to degranulation of mast cells can also cause anaphylaxis. Food allergy is the most common cause of anaphylaxis, followed by drugs. Patients with anaphylaxis commonly present with symptoms involving skin or mucous membranes, followed by respiratory and gastrointestinal symptoms...

Importance: As of May 2021, more than 32 million cases of COVID-19 have been confirmed in the United States, resulting in more than 615 000 deaths. Anaphylactic reactions associated with the Food and Drug Administration (FDA)-authorized mRNA COVID-19 vaccines have been reported. Objective: To characterize the immunologic mechanisms underlying allergic reactions to these vaccines. Design, Setting, and Participants: This case series included 22 patients with suspected allergic reactions to mRNA COVID-19 vaccines between December 18, 2020, and January 27, 2021, at a large regional health care network...

BACKGROUND: Cow's milk allergy (CMA) is the most common IgE-mediated food allergy and Bos d 5 is the major allergen in cow's milk proteins. More than 60% of the patients with CMA are sensitized to this protein. METHODS AND RESULTS: A recombinant protein, encoded by a synthetic gene and consisting of reassembled Bos d 5 fragments, was expressed in E. coli strain BL21 (DE3) cells and purified to homogeneity. The B5M lacked relevant IgE-reactivity and allergenic activity compared with Bos d 5 in dot-blot and basophil activation assays...

Purpose: The relationship between food allergy caused by food specific IgG antibodies and migraine has received increased attention in recent years. Here, we aimed to evaluate the effects of food specific IgG antibodies on headache, gastrointestinal symptoms, anxiety, depression, sleep disorders, dermatosis, and serum inflammatory cytokines in migraine patients, and to quantitatively assess the effect of IgG levels on the severity of headache and its comorbidities. Methods: Of 89 migraine patients, those who had one or more food specific IgG antibodies ≥50 U/mL were classified into the IgG positive group, which was then further divided into subgroups based on differing numbers of food allergens...

Anaphylaxis is a severe, acute, life-threatening multisystem allergic reaction resulting from the release of a plethora of mediators from mast cells culminating in serious respiratory, cardiovascular and mucocutaneous manifestations that can be fatal. Medications, foods, latex, exercise, hormones (progesterone), and clonal mast cell disorders may be responsible. More recently, novel syndromes such as delayed reactions to red meat and hereditary alpha tryptasemia have been described. Anaphylaxis manifests as sudden onset urticaria, pruritus, flushing, erythema, angioedema (lips, tongue, airways, periphery), myocardial dysfunction (hypovolemia, distributive or mixed shock and arrhythmias), rhinitis, wheezing and stridor...

Both functional abdominal pain disorders (FAPDs) and food allergies are relatively common in children and adolescents, and most studies report an association between FAPDs and allergic conditions. FAPDs share pathophysiologic processes with allergies, including both immune and psychological processes interacting with the microbiome. No conclusive data are implicating IgE-mediated reactions to foods in FAPDs; however, there may be patients who have IgE reactions localized to the gastrointestinal mucosa without systemic symptoms that are not identified by common tests...

Anaphylaxis is a severe multisystem reaction that occurs rapidly after the introduction of an antigen that would otherwise be a harmless substance. It is characterized by airway and respiratory problems, cardiovascular collapse, mucosal inflammation, and other complications, all severe symptoms that can cause death. IgE-dependent anaphylaxis involves mast cells (MCs) which are the main sources of biologically active mediators that contribute to the pathological and lethal phenomena that can occur in anaphylaxis...

BACKGROUND: Immediate food-allergic reactions are IgE-mediated, but many individuals with detectable allergen-specific IgE do not react to the food. Allergen-specific IgG may interfere with allergen-IgE interaction and/or through intracellular inhibitory signalling to suppress mast cell and basophil response to food allergens. We aimed to understand the role of allergen-specific IgG in food allergy and natural tolerance. METHODS: IgG and IgG isotypes specific to peanut, cow's milk and egg were measured using ImmunoCAP and ELISA respectively in samples of children with suspected food allergies...

Anaphylaxis is a rapidly evolving, acute, life-threatening reaction that occurs rapidly on contact with a trigger. Anaphylaxis is classically defined as an allergen-driven process that induces specific IgE and the activation of mast cells and basophils through the cross-linking of IgE receptors. However, it is clear that non-IgE-mediated pathways can induce symptoms indistinguishable from those of classic anaphylaxis, and their activation could explain the severity of IgE-mediated anaphylaxis. Indeed, mast cells and basophils can be activated by antibodies against IgE or their receptors, by molecules such as anaphylatoxins, or through G-coupled receptors...

Food allergy is a growing public health problem with ~15 million people affected in the United States. In allergic food disease, IgE on mast cells bind to ingested antigens leading to the activation and degranulation of mast cells. Stem cell factor (SCF) is mast cell growth and activation factor that is required for peripheral tissue mast cells. We targeted a specific isoform of SCF, the larger 248 amino acid form, that drives peripheral tissue mast cell differentiation using a specific monoclonal antibody in a model of food allergy...

Our understanding of the immune basis of food allergy has grown rapidly in parallel with the development of new immune-targeted interventions for the treatment of food allergy. Local tissue factors, including the composition of skin and gastrointestinal microbiota and production of Th2-inducing cytokines (TSLP, IL-33, and IL-25) from barrier sites, have been shown not only to contribute to the development of food allergy, but also to act as effective targets for treatment in mice. Ongoing clinical trials are testing the targeting of these factors in human disease...

Biologics are drugs that are derived or synthesized from biological sources. A particular class are recombinant monoclonal antibodies. Their targeted application against distinct molecules of intercellular communication is of significant relevance in the treatment of tumor, inflammatory, or allergic diseases. But also in the context of allergen immunotherapy (AIT) they can be of special value. This is exemplified by the anti-IgE antibody omalizumab, which allows to achieve allergen tolerance in patients suffering from severe allergic reactions and increased risk of AIT-induced anaphylaxis...

Food allergy is on the rise, and preventive/therapeutic procedures are needed. We explored a preventive protocol for milk allergy with the oral administration of a Gly-m-Bd-30K soy-derived peptide that contains cross-reactive epitopes with bovine caseins. B/T-cross-reactive epitopes were mapped using milk-specific human sera and monoclonal antibodies on overlapping and recombinant peptides of Gly-m-Bd-30K by SPOT and cell proliferation assays. Bioinformatics tools were used to characterize epitopes on the 3D-modelled molecule, and to predict the binding to HLA alleles...

non-IgE and mixed gastrointestinal food allergies present various specific, well-characterized clinical pictures such as food protein-induced allergic proctocolitis, food protein-induced enterocolitis and food protein-induced enteropathy syndrome as well as eosinophilic gastrointestinal disorders such as eosinophilic esophagitis, allergic eosinophilic gastroenteritis and eosinophilic colitis. The aim of this article is to provide an updated review of their different clinical presentations, to suggest a correct approach to their diagnosis and to discuss the usefulness of both old and new diagnostic tools, including fecal biomarkers, atopy patch tests, endoscopy, specific IgG and IgG4 testing, allergen-specific lymphocyte stimulation test (ALST) and clinical score (CoMiss)...

Food allergy is a major health issue, affecting the lives of 8% of U.S. children and their families. There is an urgent need to identify the environmental and endogenous signals that induce and sustain allergic responses to ingested allergens. Acute reactions to foods are triggered by the activation of mast cells and basophils, both of which release inflammatory mediators that lead to a range of clinical manifestations, including gastrointestinal, cutaneous, and respiratory reactions as well as systemic anaphylaxis...

BACKGROUND: IgE production against innocuous food antigens can result in anaphylaxis, a severe life-threatening consequence of allergic reactions. The maintenance of IgE immunity is primarily facilitated by IgG+ memory B cells, as IgE+ memory B cells and IgE+ plasma cells are extremely scarce and short-lived, respectively. OBJECTIVE: Our aim was to investigate the critical requirements for an IgE recall response in peanut allergy. METHODS: We used a novel human PBMC culture platform, a mouse model of peanut allergy, and various experimental readouts to assess the IgE recall response in the presence and absence of IL-4Rα blockade...

INTRODUCTION: Combination vaccines containing whole-cell pertussis antigens were phased out from the Australian national immunisation programme between 1997 and 1999 and replaced by the less reactogenic acellular pertussis (aP) antigens. In a large case-control study of Australian children born during the transition period, those with allergist diagnosed IgE-mediated food allergy were less likely to have received whole-cell vaccine in early infancy than matched population controls (OR: 0...

Oral food challenges remain the gold standard for the diagnosis of food allergy. Nevertheless, the allergy workup is based on the presence of a clinical history, which is evocative of an immune-allergic reaction, and the first assessment is usually the performance of skin prick tests. Based on these results, allergists are used to evaluate the presence of serum-specific IgE, which are today the most commonly prescribed in vitro test for the evaluation of a possible food allergy. Other in vitro tests include the basophil activation test, that is becoming more and more employed by clinicians and not only by researchers, and the evaluation of serum IgG4, which is still an issue of debate in the allergy community...