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Background: The efficacy of an allergen-specific IgG cocktail to treat cat allergy suggests that allergen-specific IgG may be a major protective mechanism elicited by allergen immunotherapy., Objectives: Extending these findings, we tested a Bet v 1-specific antibody cocktail in birch-allergic subjects., Methods: This was a phase 1, randomized, double-blind, study with 2 parts. Part A administered ascending doses of the Bet v 1-specific antibody cocktail REGN5713/14/15 (150-900 mg) in 32 healthy adults. Part B administered a single subcutaneous 900-mg dose or placebo in 64 birch-allergic subjects. Total nasal symptom score response to titrated birch extract nasal allergen challenge and skin prick test (SPT) with birch and alder allergen were assessed at screening and days 8, 29, 57, and 113 (SPT only); basophil activation tests (n = 26) were conducted., Results: Single-dose REGN5713/14/15 significantly reduced total nasal symptom score following birch nasal allergen challenge relative to baseline. Differences in total nasal symptom score areas under the curve (0-1 hour) for subjects treated with REGN5713/14/15 versus those given placebo (day 8: -1.17, P = .001; day 29: -1.18, P = .001; day 57: -0.85, P = .024) and titration SPT with birch difference in area under the curve of mean wheal diameters for subjects treated with REGN5713/14/15 versus placebo (all P < .001) were sustained for ≥2 months; similar results were observed with alder SPT. REGN5713/14/15 was well tolerated. Basophil responsiveness to birch-related allergens was significantly decreased in subjects treated with REGN5713/14/15 versus those given placebo on days 8, 57, and 113 (all P < .01)., Conclusions: Single-dose REGN5713/14/15 was well tolerated and provided a rapid (1 week) and durable (2 months) reduction in allergic symptoms after birch allergen nasal allergen challenge, potentially offering a new paradigm for the treatment of birch allergy symptoms., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Diagnostic allergens are defined as medicinal products in the EU. Marketing authorization by national authorities is necessary; however, diagnostic allergens are not homogeneously regulated in different EU member states. Allergen manufacturers argue with increasing costs forcing them to continuously reduce the diagnostic allergen portfolios offered to allergists. In contrast, EAACI and national European Allergy Societies see the need for the availability of a wide range of high-quality diagnostic allergens for in vivo diagnosis of IgE-mediated allergies not only covering predominant but also less frequent allergen sources. In a recent EAACI task force survey, the current practice of allergy diagnosis was shown to rely on skin tests as first option in almost 2/3 of all types of allergic diseases and in 90% regarding respiratory allergies. With the need to ensure the availability of high-quality diagnostic allergens in the EU, an action plan has been set up by EAACI to analyse the current regulatory demands in EU member states and to define possible solutions stated in this document: (a) simplification of authorization for diagnostic allergens; (b) specific regulation of special types of diagnostic allergens; (c) new models beyond the current model of homologous groups; (d) simplification of pharmacovigilance reporting; (e) reduction of regulation fees for diagnostic allergens; (f) reimbursement for diagnostic allergens. Joining forces of allergists, manufacturers and authorities are of high importance to ensure remaining relevant allergens in the EU markets to facilitate a sustainable and comprehensive service for the diagnosis and treatment of allergic diseases., (© 2020 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.)

In patients with allergic rhinitis (AR), the nasal provocation test (NPT) is the standard procedure to evaluate the clinical response of the nasal mucosa to allergens with a high specificity and sensitivity. In AR, it is the only test that really measures the response of the diseased mucosa to allergens while skin prick test and serum IgE confirm the clinical suspicion of sensitization. Moreover, it is of special relevance in the detection of patients with Local Allergic Rhinitis (LAR), where general sensitization cannot be measured. For the evaluation of therapeutic interventions, NPT has been used for the clinical monitoring of antiallergic drugs and allergen specific immunotherapy. Legislation within the European Union (EU) defines allergens used for diagnostic tests like NPT to be medicinal products according to Directive 2001/83 EC, but national law is considering these products to be medicinal devices in a number of EU countries. Thus, NPT products are governed by different legislations and therefore standards throughout the EU. In consequence, allergens used for diagnostic purposes need different registrations and Marketing Authorization by national authorities. After a transition period, regulations of EU Directives are to be implemented in national law by all member states. At the moment, most EU countries have not fully implemented these Directives, however, it can be expected that most countries will implement it and enforce their rules within the next years. This development has a tremendous impact on the availability of diagnostic allergens for NPT in Europe and will make make nasal provocation testing very difficult if not impossible. We describe the current situation of diagnostic allergens under the special legislative conditions in the EU with special focus on allergen products used for NPT and the consequences for the diagnosis of AR and LAR.

Background: The naso-ocular interaction in allergic rhinoconjunctivitis is well recognized from epidemiological, clinical, and experimental observations. The precise mechanisms remain incompletely understood. A new mouse model of allergic rhinoconjunctivitis was used to investigate the contribution of mast cells and trigeminal ganglia activation to conjunctival (conj.) inflammation after nasal allergen provocation., Methods: Sensitized mice were exposed to ovalbumin (OVA) via the nose and/or conjunctiva, and conj. homogenates were analyzed for histamine and substance P (using ELISA) and by eosinophil peroxidase (EPO) and beta-hexosaminidase assays. The conj. effects of nasal allergen deposition were compared with those induced by the mast cell activator C48/80 and with pretreatment of the mast cell stabilizer ketotifen or the transient receptor potential channel receptor (TRP) agonist capsaicin. Protachykinin 1 (TAC1) expression was quantified in the trigeminal ganglia using real time polymerase chain reaction., Results: At 1 hour after nasal application of OVA, increased conj. levels of beta-hexosaminidase (0.68 ± 0.03 nm versus 0.56 ± 0.02 nm; p = 0.02), histamine (751.1 ± 52.17 ng/mL versus 546.3 ± 76.91 ng/mL; p = 0.05), and EPO (0.66 ± 0.09 nm versus 0.37 ± 0.03 nm; p = 0.02) were detected compared with saline. Higher levels of TAC1 expression were found in the trigeminal ganglia at 24 hours after OVA application (1326 ± 255 versus 687.5 ± 90.77 TAC1/beta-actin; p = 0.04). Nasal challenge with C48/80 increased substance P and beta-hexosaminidase levels in the conjunctiva, as well as TAC1 expression. Pretreatment with ketotifen resulted in lower levels of substance P as well as TAC1 expression. Destruction of sensory nerves in the nose by capsaicin reduced the OVA-induced conj. levels of substance P, histamine, and beta-hexosaminidase., Conclusion: Nasal allergen deposition in sensitized mice induced trigeminal TAC1 expression and conj. mast cell degranulation. These data represent a significant step forward in understanding the close interaction between nasal and conj. inflammation in allergy.

Although the concept of "global airway allergy" has become widely accepted during recent years, nasobronchial interaction and its mechanisms remain incompletely understood. The experimental study of the effect of nasal allergen deposition on lower airway pathology is hampered by the difficulty of avoiding lower airway penetration of the allergens. In ovalbumin-sensitized mice with experimental airway allergy, nasal allergen provocations were performed after complete anatomical separation of upper and lower airways by means of a tracheotomy. A canula was inserted in the trachea, and the trachea was ligated, thus inhibiting any passage of allergens from upper to lower airways. Mice showed bronchial hyperresponsiveness to methacholine as early as 4 hours after nasal allergen provocation in the absence of recruitment of inflammatory cells. An increased substance P (SP) concentration in the bronchial lumen was found, as well as an increased number of SP-positive pulmonary nerves. Treatment with a neurokinin (NK) 1 receptor antagonist abolished the allergen-induced bronchial hyperresponsiveness. Moreover, endobronchial administration of SP caused NK1 receptor-dependent bronchial hyperresponsiveness in mice with airway allergy. Nasal allergen provocation rapidly induces bronchial hyperresponsiveness via pulmonary up-regulation of SP and activation of NK1 receptors.

In spite of our recent insight into nasobronchial interaction mechanisms in allergic airway disease, the association between allergic rhinitis and voice complaints remains obscure. To evaluate the effects of nasal allergen provocation and seasonal grass pollen exposure on subjective and objective laryngeal parameters in singers with and without allergic rhinitis, an observational case control study was conducted. Prior to the pollen season, six grass pollen allergic and six non-allergic semiprofessional singers were exposed to nebulized sham solution and grass pollen extract (HAL°) in rising concentrations. After 3 min, 60 min and 24 h, nasal and laryngeal complaints were evaluated by the use of a visual analog scale (VAS). Laryngeal parameters like voice appearance (video stroboscopic images), voice range profile and subjective (GRBAS) and objective (jitter, shimmer, H/N, DSI) voice quality were evaluated before provocation, after 60 min and 24 h. During the pollen season, the allergic singers were re-evaluated. Results showed that in allergic singers both nasal (TNS of 4.0 ± 2.4 vs. 0.0 ± 0.0, p < 0.05) and laryngeal complaints (TLS of 1.4 ± 1.1 vs. 0.0 ± 0.2, p < 0.05) were induced at 3 min after the provocation. The induced laryngeal complaints were the feeling of laryngeal irritation, secretions and globus. No change in voice quality or stroboscopy score was measured. During the pollen season, laryngeal complaints were present (TLS of 2.4 ± 2.4) in allergic singers, without evidence for objective voice and laryngeal changes. In conclusion, we here demonstrate the rapid induction of laryngeal complaints in allergic singers by nasal allergen provocation and during the pollen season. There was no subject reported or investigator measured change in voice quality. No change in stroboscopy score was measured.

Objectives: The epidemiology of specific sensitization to inhalant allergens remains unknown in patients at tertiary rhinology clinics. We used skin prick testing (SPT) to assess sensitization to major aeroallergens in order to evaluate the prevalence of specific rhinologic diseases, the frequency of polysensitization and the relationship between nasal symptoms, nasal endoscopy parameters, diagnosis and sensitization., Methods: A retrospective review of medical records was conducted at the ENT Department of the Catholic University Hospital in Leuven, Belgium. The study analyzed the medical data of patients with rhinologic symptoms suspected of having allergies., Results: The study included 1326 patients with a mean age of 35 +/- 18 years (range: 3-88 years); 52.8% were males. Rhinitis without nasal abnormalities (42.1%), chronic rhinosinusitis without nasal polyps (16.5%) and nasal abnormalities (16.1%) were the most prevalent findings. About 31.6% of patients were sensitive to at least one allergen, and the most common aeroallergens were dermatophagoides pteronyssinus (62.1%) and grass pollen (53.2%). Polysensitization was found in 54.2%. The most prevalent clinical symptoms in allergic rhinitis patients were nasal obstruction, clear/watery nasal discharge, sneezing, postnasal drip and headache. Clear nasal discharge, sneezing, and itchy nose and eyes (p < 0.05 for all) were significantly higher in sensitized patients. In contrast, postnasal drip, headache and purulent nasal discharge were also observed in non-sensitized patients (p < 0.05 for all)., Conclusions: At a rhinology clinic at a university ENT clinic, 31.6% of the patients had positive SPT results, mainly to house dust mites and grass pollen. Among sensitized patients, 54.2% were polysensitized.

Background: Several clinical and experimental observations suggest that allergen deposition in the nose may partially be responsible for the induction of conjunctival symptoms in allergic rhinitis. The aims of this study were to evaluate the induction of conjunctival symptoms by selective nasal allergen provocation and to assess the feasibility of the different tools for evaluation of conjunctival allergic inflammation., Methods: Grass pollen allergic subjects with rhinoconjunctivitis symptoms during the pollen season (n = 12) underwent a nasal sham and grass pollen provocation extra-seasonally. Nasal and conjunctival symptoms were scored using the Visual Analogue Scale (VAS) system at baseline, 15 min, 1 h and 24 h after provocation. In addition to Peak Nasal Inspiratory flow (PNIF) measurements, conjunctival inflammation and vascular congestion were evaluated and histamine and substance P levels in tear fluid were measured., Results: Selective nasal grass pollen provocation induced ocular pruritus, lacrimation and conjunctival vascular congestion. PNIF values correlated inversely with lacrimation (r = -0.71, P < 0.001) and ocular pruritus (r = -0.41, P < 0.05). Four out of 11 patients showed a conjunctival eosinophilic inflammation and levels of histamine (r = 0.73, P < 0.05) and substance P (r = 0.67, P = 0.05) in tear fluid correlated with conjunctival symptoms., Conclusion: Selective nasal grass pollen provocation induced conjunctival inflammation, ocular pruritus and lacrimation, which correlated with histamine and substance P levels in tear fluid and inversely with the PNIF values. These data show a naso-ocular interaction in allergic rhinitis and offer objective tools for evaluation of conjunctival inflammation in allergic rhinoconjunctivitis.

Interleukin (IL)-17 is produced by activated memory CD4(+) cells and induces cytokines and chemokines that stimulate neutrophil generation and recruitment. Here, we investigated the involvement of IL-17 in the bronchial influx of neutrophils in experimental allergic asthma. Inhalation of nebulized ovalbumin (OVA) by sensitized mice with bronchial eosinophilic inflammation resulting from chronic OVA exposure induced early IL-17 mRNA expression in inflamed lung tissue, concomitant with a prominent bronchial neutrophilic influx. Anti-IL-17 monoclonal antibodies (mAb) injected before allergen inhalation strongly reduced bronchial neutrophilic influx, in a manner equally as potent as the anti-inflammatory dexamethasone. Remarkably, anti-IL-17 mAb significantly enhanced IL-5 levels in both BAL fluid and serum, and aggravated allergen-induced bronchial eosinophilia. In another series of experiments, anti-IL-17 mAb were given repeatedly during the inhalatory challenge phase with OVA of sensitized mice. This treatment regimen abated bronchial neutrophilia in parallel with reduction of bone marrow and blood neutrophilia. In addition, anti-IL-17 mAb treatment elevated eosinophil counts in the bone marrow and bronchial IL-5 production, without alteration of allergen-induced bronchial hyperresponsiveness. In summary, our results demonstrate that IL-17 expression in airways is upregulated upon allergen inhalation, and constitutes the link between allergen-induced T cell activation and neutrophilic influx. Because neutrophils may be important in airway remodeling in chronic severe asthma, targeting IL-17 may hold therapeutic potential in human asthma.

Background: Allergic rhinitis is a risk factor for the development of asthma. About 80% of asthmatic patients also have rhinitis. However, the pattern of induction of allergic rhinitis and asthma remains unclear., Objective: The purpose of this study was to investigate the development of upper airway inflammation in mice during the development of an asthma-like disease and after an acute allergen provocation., Methods: BALB-c mice were sensitized intraperitoneally (i.p) to ovalbumin (OA, days 1-13) and were challenged with aerosols of either OA or saline on 8 consecutive days (days 33-40). In a second experiment, chronic exposure for 8 days was followed by 10 days of rest and then an acute nebulized allergen provocation was performed (day 50). Inflammatory parameters were investigated at different time-points., Results: Upper and lower eosinophilic airway inflammation were simultaneously induced in the course of repeated inhalations of nebulized OA, as shown by analyses of nasal and broncho-alveolar lavage fluids and histological sections of the nose and bronchi. Mice that developed bronchial hyper-responsiveness also had increased thickness of the nasal mucosa on magnetic resonance image (MRI) scans. When chronic exposure was followed by acute allergen provocation, the latter caused a systemic increase in IL-5 levels, with a concomitant rise in blood and airway eosinophils, primarily in the nose., Conclusions: Simultaneous induction of eosinophilic inflammation in the nose and lungs was found in a mouse model of respiratory allergy. These findings support the viewpoint that upper and lower airway disease represent a continuum of inflammation involving one common airway and provide evidence for the concept of global airway inflammation after inhalation of allergen.