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Manufacturing food extracts
Published in Richard F. Lockey, Dennis K. Ledford, Allergens and Allergen Immunotherapy, 2020
Natalie A. David, Anusha Penumarti, Jay E. Slater
There are several novel approaches on the horizon for standardization of allergen extracts. The European Union CREATE project worked to develop certified recombinant reference materials and validated monoclonal antibody–based immunoassays for measurement of specific allergens [111]. Other researchers have developed additional assays for quantification of major allergens; examples include assays for Ara h 1 and Ara h 2 [112]. Another potential method for standardization would utilize tandem mass spectrometry (MS/MS). MS/MS-based approaches have the advantage of simultaneous detection of many allergens and their unique isoforms [28]. The multiplex allergen extract potency assay has only been applied to aeroallergens so far but may be applied to complex food allergens as well [113].
Lactic Acid Bacteria Application to Decrease Food Allergies
Published in Marcela Albuquerque Cavalcanti de Albuquerque, Alejandra de Moreno de LeBlanc, Jean Guy LeBlanc, Raquel Bedani, Lactic Acid Bacteria, 2020
Vanessa Biscola, Marcela Albuquerque Cavalcanti de Albuquerque, Tatiana Pacheco Nunes, Antonio Diogo Silva Vieira, Bernadette Dora Gombossy de Melo Franco
Regarding the implicated antigens, the pattern of sensitization to peanut proteins varies among populations in different geographical regions. The three main elicitors of allergic reactions in the U.S. are Ara h 1, Ara h 2, and Ara h 3. In Spain, Ara h 9 is the most antigenic protein, while for Swedish patients Ara h 8 has the highest sensitization rates (Vereda et al. 2011, Ballmer-Weber et al. 2015).
Recombinant Food Allergens for Diagnosis and Therapy
Published in Andreas L. Lopata, Food Allergy, 2017
Heidi Hofer, Anargyros Roulias, Claudia Asam, Stephanie Eichhorn, Fátima Ferreira, Gabriele Gadermaier, Michael Wallner
The study was placebo controlled and showed clinical efficacy in the actively treated group; however, the rate of systemic side effects was > 13%. Moreover, due to a formulation error in the pharmacy, a patient within the placebo group received the maintenance dose of peanut extract and died of anaphylaxis—a fact that led to the termination of the study (Oppenheimer et al. 1992). In a small study with 12 peanut allergic patients published five years later, the aim was again the treatment of peanut allergies using a rush protocol based on peanut extracts. The study was clinically efficacious in some patients, whereas half of the actively treated patients did not show much of improvement in a double-blind placebo-controlled food challenge after one year of treatment. Of note, the patients who could not tolerate the full maintenance dose had a high rate of systemic reactions during updosing (average 9.8 epinephrine injections per subject were necessary), but also side effects during the maintenance phase (12.6 epinephrine injections per subject) were high (Nelson et al. 1997, Nowak-Wegrzyn and Sampson 2011). This indicates a general problem of extract-based AIT of food allergies. Allergen extracts are hardly standardizable, heterogeneous mixtures of easily extractable compounds from a food source. The cocktail ideally contains sufficient amounts of the disease-eliciting allergens to induce tolerance. However, unmodified allergen extracts bear the risk of the induction of IgE-mediated side effects, which are difficult to control and may end fatal. To avoid such problems, AIT concepts based on recombinant food allergens have been developed. Therefore, the disease eliciting allergens need to be identified within the allergen source and selected for the use in AIT. Most AIT trials were performed for inhalant allergies based on formulations with a single allergen (Ferreira et al., 2014), though, for grass pollen allergies, a cocktail consisting of four major allergens has been successfully tested (Jutel et al. 2005). In peanut allergy, Ara h 1, 2, and 3 represent major allergenic components. The IgE-binding epitopes of the three allergens have been identified and amino acids critical for the binding sites have been replaced resulting in proteins with reduced IgE-binding properties (Bannon et al. 2001). In a new vaccination strategy, the recombinant allergens were independently expressed in E. coli,the host cells were killed by treatment with heat and phenol, and thereafter the E. coli-encapsulated allergens were formulated as vaccine for rectal application (EMP-123). In a phase I trial, EMP- 123 was tested in five healthy individuals in a four week schedule without inducing adverse reactions. Thereafter, ten peanut-allergic patients were treated in an updosing regimen for ten weeks followed by three biweekly administered maintenance doses. Due to side- effects five patients could not complete the trial, whereas four had no and one patient only mild symptoms (Wood et al. 2013).
Role of dendritic cells in peanut allergy
Published in Expert Review of Clinical Immunology, 2018
Raquel Aguilera-Insunza, Luis F. Venegas, Mirentxu Iruretagoyena, Leticia Rojas, Arturo Borzutzky
Until now, 15 peanut allergens have been identified, termed Arachis hypogaea (Ara h) 1 to Ara h 15 (Table 1) [15-18]. Food allergens are classified into families and superfamilies according to their amino acid sequences, structure and function homology [14]. Most peanut allergens are members of the seed storage protein families. The major peanut allergens Ara h 1 and Ara h 2 are members of the cupin and prolamin superfamilies, respectively, and Ara h 2 is the most important member, with a sensitization rate of 42%–100% in PA-affected patients [19,20]. Ara h 8, a protein that is homologous to the major birch pollen allergen Betula verrucosa 1 (Bet v 1), is relevant in patients with combined birch pollen and PA, especially in Northern Europe [21]. In contrast, Ara h 9 is a lipid transfer protein, an important allergen in PA patients from the Mediterranean area [21].
Current Trend in Immunotherapy for Peanut Allergy
Published in International Reviews of Immunology, 2018
Chong Joo Chan, Timmy Richardo, Renee Lay Hong Lim
A total of 17 peanut allergens has been identified and recognised by the WHO/IUIS Allergen Nomenclature Sub-committee. They were characterised based on their biological function and placed in protein superfamilies such as the Cupin, Prolamin, Bet v-1 like, Profilin Glycosyl transferase GT-C, Scorpion toxin-like knottin and the recently reported lipid transfer proteins as shown in Table 2.60 Among these allergens, Ara h 1, Ara h 2 and Ara h 3 are classified as the major peanut allergens due to their ability to recognise IgE in more than 50% of peanut-allergic patients.61 Ara h 6 was reported to exhibit similar allergenic potential and activity as Ara h 2.62