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Volpicella M.,University of Bari | Leoni C.,University of Bari | Fanizza I.,University of Bari | Placido A.,National Research Council Italy | And 2 more authors.
Journal of Agricultural and Food Chemistry | Year: 2014

Food allergies are induced by proteins belonging to a limited number of families. Unfortunately, relationships between protein structure and capacity to induce the immune response have not been completely clarified yet, which precludes possible improvements in the diagnosis, prevention, and therapy of allergies. Plant chitinases constitute a good example of food allergenic proteins for which structural analysis of allergenicity has only been carried out partially. In plants, there are at least five structural classes of chitinases plus a number of chitinase-related polypeptides. Their allergenicity has been mostly investigated for chitinases of class I, due to both their higher prevalence among plant chitinases and by the high structural similarity between their substrate-binding domain and hevein, a well-known allergen present in the latex of rubber trees. Even if allergenic molecules have been identified for at least three other classes of plant chitinases, the involvement of the different structural motifs in the allergenicity of molecules has been disregarded so far. In this review, we provide a structurally based catalog of plant chitinases investigated for allergenicity, which could be a useful base for further studies aimed at better clarifying the structure-allergenicity relationships for this protein family. © 2014 American Chemical Society. Source

Bezzi M.,Respiratory Endoscopy and Lasertherapy Center | Solidoro P.,Unit of Pneumology | Patella V.,Unit of Allergology and Immunology | Contoli M.,University of Ferrara | Scichilone N.,University of Palermo
Minerva Medica | Year: 2014

Asthma is a complex inflammatory disorder of the airways characterized by airway hyper-responsiveness and variable, reversible, airflow obstruction. Bronchial thermoplasty (BT) is a new modality for treating asthma. It targets airway smooth muscles (ASM) by delivering a controlled specific amount of thermal energy (radiofrequency ablation) to the airway wall through a dedicated catheter. The use of bronchial thermoplasty has been widely discussed for its potential in the treatment of asthma, since it seems to be able to reduce the symptoms of asthma. The definitive study for BT (AIR2 trial) employed a randomized, double-blind, sham-controlled design and enrolled 288 subjects with severe persistent asthma from 30 US and international centers. The results of the AIR2 trial demonstrated clinically significant benefits of BT compared with the sham group at one year post-treatment, including an improvement in asthma-related quality of life, 32% reduction in severe exacerbations, 84% reduction in emergency department visits for asthma symptoms, and a 66% reduction in time lost from work/school/other daily activities because of asthma symptoms. Preclinical work showed that ASM is reduced after BT by at least 3 years after treatment. The recent article from the ARI2 trial study group analyses the long-term safety and effectiveness of BT in patients with severe persistent asthma and demonstrates the 5-year durability of the benefits of BT in the control of symptoms and safety. It supports the evidence that reduction in asthma attacks, ER visits, and hospitalizations for respiratory symptoms are maintained for at least 5 years. There is a pressing need to understand the underlying mechanism(s) of BT and how the delivered heat is translated into clinical benefit. This necessitates additional investigation to identify disease and patient characteristics that would enable accurate phenotyping of positive responders to avoid unnecessary procedures and risks. Source

Pravettoni V.,Clinical Allergy and Immunology Unit | Piantanida M.,Clinical Allergy and Immunology Unit | Primavesi L.,Clinical Allergy and Immunology Unit | Forti S.,Unit of Audiology | Pastorello E.A.,Unit of Allergology and Immunology
Clinical and Molecular Allergy | Year: 2015

Background: Venom immunotherapy (VIT) is an effective treatment for subjects with systemic allergic reactions (SR) to Hymenoptera stings, however there are few studies concerning the relevance of the venom specific IgE changes to decide about VIT cessation. We assessed IgE changes during a 5-year VIT, in patients stung and protected within the first 3 years (SP 0-3) or in the last 2 years (SP 3-5), and in patients not stung (NoS), to evaluate possible correlations between IgE changes and clinical protection. Methods: Yellow jacket venom (YJV)-allergic patients who completed 5 years of VIT were retrospectively evaluated. Baseline IgE levels and after the 3rd and the 5th year of VIT were determined; all patients were asked about field stings and SRs. Results: A total of 232 YJV-allergic patients were included and divided into the following groups: 84 NoS, 72 SP 0-3 and 76 SP 3-5. IgE levels decreased during VIT compared to baseline values (χ2 = 346.029, p < 0.001). Recent vespid stings accounted for significantly higher IgE levels despite clinical protection. IgE levels after 5 years of VIT correlated significantly with Mueller grade (F = 2.778, p = 0.012) and age (F = 6.672, p = 0.002). During follow-up from 1 to 10 years after VIT discontinuation, 35.2 % of the contacted patients reported at least one field sting without SR. Conclusions: The yellow jacket-VIT temporal stopping criterion of 5 years duration did not result in undetectable IgE levels, despite a long-lasting protection. A mean IgE decrease from 58 to 70 % was observed, and it was less marked in elderly patients or in subjects with higher Mueller grade SR. © 2015 Pravettoni et al. Source

Matricardi P.M.,Charite - Medical University of Berlin | Kleine-Tebbe J.,Allergy & Asthma Center Westend | Hoffmann H.J.,Aarhus University Hospital | Valenta R.,Medical University of Vienna | And 67 more authors.
Pediatric Allergy and Immunology | Year: 2016

The availability of allergen molecules (‘components’) from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled ‘component-resolved diagnosis’ (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Source

Prandi B.,University of Parma | Tedeschi T.,University of Parma | Pastorello E.A.,Unit of Allergology and Immunology | Sforza S.,University of Parma
Rapid Communications in Mass Spectrometry | Year: 2012

RATIONALE Non-specific lipid transfer proteins (ns-LTPs) are major food allergens of the RosaceÃ∥ family. The severity of allergic reactions often relates to resistance of the allergen to digestion. Thus, it is important to evaluate the digestibility of these proteins and characterise the peptides generated in the gastrointestinal tract. METHODS Simulated gastrointestinal digestion of purified allergen Pru ar 3 was performed using pepsin for the gastric phase in aqueous HCl at pH = 2 and chymotrypsin and trypsin for the intestinal phase in aqueous NH4HCO3 at pH = 7.8. The peptide mixture obtained was analysed by ultra-performance liquid chromatography/electrospray ionisation mass spectrometry (UPLC/ESI-MS). Peptide sequences were identified by comparing their molecular mass to that obtained by in silico digestion, and were confirmed by the ions obtained by in-source fragmentation. Semi-quantification was performed for the intact protein by comparison with internal standards. RESULTS The resistance to gastrointestinal digestion of Pru ar 3 allergen was evaluated to be 9%. This value is consistent with that found for grape LTP, but much lower than the resistance found for peach LTP (35%). All the peptides generated were identified by ESI-MS on the basis of their molecular mass and from the ions generated from in-source fragmentation. Apart from low molecular mass peptides, five high molecular mass peptides (4500-7000 Da) containing disulphide bridges were identified. ESI-MS of the intact protein indicated a less compact folded structure when compared to that of the homologous peach LTP. CONCLUSIONS An extensive characterisation of the peptides generated from the gastrointestinal digestion of Pru ar 3 allergen was performed here for the first time via UPLC/ESI-MS analysis. The digestibility of the allergen was evaluated and compared with that of other LTPs, demonstrating that only a small amount of undigested protein remains, and that specific proteolytic action involves immunodominant epitopes. These data might explain the lower allergenicity of apricot LTP compared to peach LTP, despite their high sequence homology. Copyright © 2012 John Wiley & Sons, Ltd. Source

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