Olfactory Loss in Rhinosinusitis: Mechanisms of Loss and Recovery.

Chronic rhinosinusitis (CRS) is a highly prevalent disease and up to 83% of CRS patients suffer from olfactory dysfunction (OD). Because OD is specifically seen in those CRS patients that present with a type 2 eosinophilic inflammation, it is believed that type 2 inflammatory mediators at the level of the olfactory epithelium are involved in the development of this olfactory loss. However, due to the difficulties in obtaining tissue from the olfactory epithelium, little is known about the true mechanisms of inflammatory OD. Thanks to the COVID-19 pandemic, interest in olfaction has been growing rapidly and several studies have been focusing on disease mechanisms of OD in inflammatory conditions. In this paper, we summarize the most recent data exploring the pathophysiological mechanisms underlying OD in CRS. We also review what is known about the potential capacity of olfactory recovery of the currently available treatments in those patients.

European Academy of Allergy and Clinical Immunology position paper on endoscopic scoring of nasal polyposis.

Nasal endoscopy is not only used for the diagnosis of chronic rhinosinusitis with nasal polyps (CRSwNP), but also for monitoring the response to therapy playing an important role in both daily practice and research. In contrast to patient-reported outcomes, endoscopic nasal polyp scoring by independent blinded readers is an objective measurement, not influenced by the placebo effect. It is safer and cheaper compared with computed tomography imaging and therefore, better suited for regular assessments of the extent of the disease. Since the early 90s, a variety of endoscopic staging methods have been proposed and used in clinical research, making it hard to compare results from different studies. This paper resulted from a task force with experts in the field of CRSwNP, originated by the Ear, Nose and Throat section of the European Academy of Allergy and Clinical Immunology and aims to provide a unified endoscopic NP scoring system that can serve as a reference standard for researchers, but also as a useful tool for practitioners involved in the management of CRSwNP.

Perceptions of adolescents and young adults with allergy and/or asthma and their parents on EAACI guideline recommendations about transitional care: A European survey.

BACKGROUND: The European Academy of Allergy and Clinical Immunology has developed a guideline to provide evidence-based recommendations for healthcare professionals to support the transitional care of adolescents and young adults (AYA) with allergy and/or asthma. The goal of this work was to ensure that the draft recommendations are also important for patients. METHODS: We surveyed patients aged 11-25 years with allergy and/or asthma and their parents across Europe between 17 February and 16 March 2020. The multilingual survey was distributed through national allergy and asthma patient organizations in Europe as well as through social media. RESULTS: A total of 1210 responses from 24 European countries were collected. There were 415 (34.3%) AYA and 795 (65.7%) parents. The majority of AYA (72.3%) and parents (81.9%) were female. Patients had a history of asthma (61.1%), allergic rhinoconjunctivitis (54.1%), food allergy (53.8%), atopic eczema (42.6%) and anaphylaxis (28.8%). All recommendations achieved the median score of either 'important' or 'very important'. The least supported recommendations were the use of joint clinics with both paediatric and adult physicians attending and the use of web-based or mobile technologies for communication with the AYA. The most supported recommendation was checking that the AYA is knowledgeable and compliant with their prescribed medication. Qualitative analysis revealed conditional approval for some recommendations. CONCLUSIONS: There was agreement from patients and parents on the importance of the draft recommendations on transitional care for AYA with allergy and/or asthma and their parents. The recommendations now need to be implemented into clinical practice across Europe.

Tackling nasal symptoms in athletes: Moving towards personalized medicine.

Adequate nasal breathing is indispensable for athletes, and nasal symptoms have been shown to interfere with their subjective feeling of comfortable breathing and quality of life. Nasal symptoms are caused by either structural abnormalities or mucosal pathology. Structural pathologies are managed differently from mucosal disease, and therefore, adequate diagnosis is of utmost importance in athletes in order to choose the correct treatment option for the individual. Literature suggests that nasal symptoms are more prevalent in athletes compared to the general population and certain sports environments might even trigger the development of symptoms. Given the high demands of respiratory function in athletes, insight into triggering factors is of high importance for disease prevention. Also, it has been suggested that athletes are more neglectful to their symptoms and hence remain undertreated, meaning that special attention should be paid to education of athletes and their caregivers. This review aims at giving an overview of nasal physiology in exercise as well as the possible types of nasal pathology. Additionally, diagnostic and treatment options are discussed and we focus on unmet needs for the management and prevention of these symptoms in athletes within the concept of precision medicine.

Management of patients with chronic rhinosinusitis during the COVID-19 pandemic-An EAACI position paper.

BACKGROUND: Chronic rhinosinusitis is regarded as a chronic airway disease. According to WHO recommendations, it may be a risk factor for COVID-19 patients. In most CRSwNP cases, the inflammatory changes affecting the nasal and paranasal mucous membranes are type-2 (T2) inflammation endotypes. METHODS: The current knowledge on COVID-19 and on treatment options for CRS was analyzed by a literature search in Medline, Pubmed, international guidelines, the Cochrane Library and the Internet. RESULTS: Based on international literature, on current recommendations by WHO and other international organizations as well as on previous experience, a panel of experts from EAACI and ARIA provided recommendations for the treatment of CRS during the COVID-19 pandemic. CONCLUSION: Intranasal corticosteroids remain the standard treatment for CRS in patients with SARS-CoV-2 infection. Surgical treatments should be reduced to a minimum and surgery preserved for patients with local complications and for those with no other treatment options. Systemic corticosteroids should be avoided. Treatment with biologics can be continued with careful monitoring in noninfected patients and should be temporarily interrupted during the course of the COVID-19 infection.

COVID-19 pandemic: Practical considerations on the organization of an allergy clinic-An EAACI/ARIA Position Paper.

BACKGROUND: The coronavirus disease 2019 (COVID-19) has evolved into a pandemic infectious disease transmitted by the severe acute respiratory syndrome coronavirus (SARS-CoV-2). Allergists and other healthcare providers (HCPs) in the field of allergies and associated airway diseases are on the front line, taking care of patients potentially infected with SARS-CoV-2. Hence, strategies and practices to minimize risks of infection for both HCPs and treated patients have to be developed and followed by allergy clinics. METHOD: The scientific information on COVID-19 was analysed by a literature search in MEDLINE, PubMed, the National and International Guidelines from the European Academy of Allergy and Clinical Immunology (EAACI), the Cochrane Library, and the internet. RESULTS: Based on the diagnostic and treatment standards developed by EAACI, on international information regarding COVID-19, on guidelines of the World Health Organization (WHO) and other international organizations, and on previous experience, a panel of experts including clinicians, psychologists, IT experts, and basic scientists along with EAACI and the "Allergic Rhinitis and its Impact on Asthma (ARIA)" initiative have developed recommendations for the optimal management of allergy clinics during the current COVID-19 pandemic. These recommendations are grouped into nine sections on different relevant aspects for the care of patients with allergies. CONCLUSIONS: This international Position Paper provides recommendations on operational plans and procedures to maintain high standards in the daily clinical care of allergic patients while ensuring the necessary safety measures in the current COVID-19 pandemic.

Multidisciplinary Care for Severe or Uncontrolled Chronic Upper Airway Diseases.

PURPOSE OF REVIEW: A multidisciplinary approach is regarded as the best practice for many chronic diseases, such as cancer and asthma, with well-documented value. There is also evidence that it may be beneficial to patients with chronic rhinosinusitis (CRS) and/or allergic airway disease presenting to tertiary referral centres. We discuss here whether and how organizing this kind of healthcare transition into a more integrated care pathway would benefit severe chronic upper airways disease (SCUAD) management. RECENT FINDINGS: Based on a recent related EUFOREA panel discussion, literature search, and review of the best overseas practices, an appropriate implementation strategy of multidisciplinary care and its potential results are presented. Organizational principles, hurdles, and challenges of the process, as well as envisaged solutions and results, are being reported. The efficiency of care and the quality control assessment are concepts that are currently gaining importance. At the same time, novel treatment options based on molecular and precision medicine advancements, such as biologics, are being increasingly prescribed. Appropriately organized multidisciplinary care teams can adapt to new demands, data, and discoveries to assure maximum benefit for both patients and healthcare professionals.

Key role of the epithelium in chronic upper airways diseases.

The respiratory epithelium of the upper airways is a first-line defence against inhaled irritants, pathogens and allergens. It ensures a physical barrier provided by apical junctions and mucociliary clearance to avoid excessive activation of the immune system. The epithelium also forms a chemical and immunological barrier, extensively equipped to protect the airways against external aggressions before the adaptive immune system is required. Under normal circumstances, the epithelium is capable of recovering rapidly after damage. This manuscript reviews these main properties of the upper airway epithelium as well as its reported impairments in chronic inflammatory diseases. The knowledge on normal epithelial functions and their dysregulation in upper airway diseases should help to design new epithelial-targeted treatments.

Understanding the challenges faced by adolescents and young adults with allergic conditions: A systematic review.

BACKGROUND: Adolescence represents a vulnerable time for individuals with asthma and allergic conditions. They suffer an unexpected degree of morbidity. This systematic review aimed to understand the challenges faced by adolescents and young adults with these conditions. METHODS: A systematic literature search was undertaken across eight databases. References were checked by two reviewers for inclusion. Study data were extracted, and their quality was assessed in duplicate. A narrative meta-synthesis was undertaken. RESULTS: A total of 108 papers describing 106 studies were retrieved, most focused on asthma. Five themes were identified across studies: (a) Health-related quality of life-impairment was associated with poor disease control, psychosocial issues, adolescent-onset allergic disease and female sex; (b) Psychological factors-asthma and food allergy were associated with anxiety and depression, atopic dermatitis was associated with suicidal ideation, and that parental emotional support may be protective; (c) Adherence-suboptimal adherence was associated with older age, barriers to medication usage, poor symptom perception and failure to take responsibility, and positive factors were routines, simpler treatment regimes, better knowledge and perceptions about medications; (d) Self-management-facilitated by education, knowledge and a positive attitude; and (e) Supportive relationships-families could modify barriers to adherence and foster positive views about self-management, adolescents suggested that their peers should be more involved in supporting them, and adolescents also wished to have support from nonjudgemental healthcare professionals. CONCLUSIONS: We have some understanding of the challenges faced by adolescents with asthma, less so for other allergic conditions. This knowledge will be used to support guidelines for managing adolescents.

The effectiveness of interventions to improve self-management for adolescents and young adults with allergic conditions: A systematic review.

BACKGROUND: This systematic review aimed to review the literature on interventions for improving self-management and well-being in adolescents and young adults (11-25 years) with asthma and allergic conditions. METHODS: A systematic literature search was undertaken across eight databases. References were checked by two reviewers for inclusion. Study data were extracted, and their quality was assessed in duplicate. A narrative synthesis was undertaken. RESULTS: A total of 30 papers reporting data from 27 studies were included. Interventions types were psychological (k = 9); e-health (k = 8); educational (k = 4); peer-led (k = 5); breathing re-training (k = 1). All interventions were for asthma. Psychological interventions resulted in significant improvements in the intervention group compared with the control group for self-esteem, quality of life, self-efficacy, coping strategies, mood and asthma symptoms. E-Health interventions reported significant improvements for inhaler technique, adherence and quality of life. General educational interventions demonstrated significantly improved quality of life, management of asthma symptoms, controller medication use, increased use of a written management plan and reduction in symptoms. The peer-led interventions included the Triple A (Adolescent Asthma Action) programme and a peer-led camp based on the Power Breathing Programme. Improvements were found for self-efficacy, school absenteeism and quality of life. CONCLUSION: Although significant improvements were seen for all intervention types, many were small feasibility or pilot studies, few studies reported effect sizes and no studies for allergic conditions other than asthma met the inclusion criteria. Research using large longitudinal interventional designs across the range of allergic conditions is required to strengthen the evidence base.

EAACI Guidelines on the effective transition of adolescents and young adults with allergy and asthma.

Adolescent and young adult (AYA) patients need additional support, while they experience the challenges associated with their age. They need specific training to learn the knowledge and skills required to confidently self-manage their allergies and/or asthma. Transitional care is a complex process, which should address the psychological, medical, educational and vocational needs of AYA in the developmentally appropriate way. The European Academy of Allergy and Clinical Immunology has developed a clinical practice guideline to provide evidence-based recommendations for healthcare professionals to support the transitional care of AYA with allergy and/or asthma. This guideline was developed by a multidisciplinary working panel of experts and patient representatives based on two recent systematic reviews. It sets out a series of general recommendations on operating a clinical service for AYA, which include the following: (a) starting transition early (11-13 years), (b) using a structured, multidisciplinary approach, (c) ensuring AYA fully understand their condition and have resources they can access, (d) active monitoring of adherence and (e) discussing any implications for further education and work. Specific allergy and asthma transition recommendations include (a) simplifying medication regimes and using reminders; (b) focusing on areas where AYA are not confident and involving peers in training AYA patients; (c) identifying and managing psychological and socio-economic issues impacting disease control and quality of life; (d) enrolling the family in assisting AYA to undertake self-management; and (e) encouraging AYA to let their friends know about their allergies and asthma. These recommendations may need to be adapted to fit into national healthcare systems.

Real-life assessment of chronic rhinosinusitis patients using mobile technology: The mySinusitisCoach project by EUFOREA.

BACKGROUND: Chronic rhinosinusitis (CRS) is a chronic inflammatory disease associated with a substantial personal and socioeconomic burden. Monitoring of patient-reported outcomes by mobile technology offers the possibility to better understand real-life burden of CRS. METHODS: This study reports on the cross-sectional evaluation of data of 626 users of mySinusitisCoach (mSC), a mobile application for CRS patients. Patient characteristics of mSC users were analysed as well as the level of disease control based on VAS global rhinosinusitis symptom score and adapted EPOS criteria. RESULTS: The mSC cohort represents a heterogeneous group of CRS patients with a diverse pattern of major symptoms. Approximately half of patients reported nasal polyps. 47.3% of all CRS patients were uncontrolled based on evaluation of VAS global rhinosinusitis symptom score compared to 40.9% based on adapted EPOS criteria. The impact of CRS on sleep quality and daily life activities was significantly higher in uncontrolled versus well-controlled patients. Half of patients had a history of FESS (functional endoscopic sinus surgery) and reported lower symptom severity compared to patients without a history of FESS, except for patients with a history of more than 3 procedures. Patients with a history of FESS reported higher VAS levels for impaired smell. CONCLUSION: Real-life data confirm the high disease burden in uncontrolled CRS patients, clearly impacting quality of life. Sinus surgery improves patient-reported outcomes, but not in patients with a history of more than 3 procedures. Mobile technology opens a new era of real-life monitoring, supporting the evolution of care towards precision medicine.

Diminution of signal transducer and activator of transcription 3 signaling inhibits vascular permeability and anaphylaxis.

BACKGROUND: During IgE-mediated immediate hypersensitivity reactions, vascular endothelial cells permeabilize in response to mast cell mediators. We have demonstrated previously that patients and mice with signal transducer and activator of transcription 3 (STAT3) mutations (autosomal dominant hyper-IgE syndrome [AD-HIES]) are partially protected from anaphylaxis. OBJECTIVES: We sought to study the mechanism by which STAT3 contributes to anaphylaxis and determine whether small-molecule inhibition of STAT3 can prevent anaphylaxis. METHODS: Using unaffected and STAT3-inhibited or genetic loss-of-function samples, we performed histamine skin prick tests, investigated the contribution of STAT3 to animal models of anaphylaxis, and measured endothelial cell permeability, gene and protein expression, and histamine receptor-mediated signaling. RESULTS: Although mouse mast cell degranulation was minimally affected by STAT3 blockade, mast cell mediator-induced anaphylaxis was blunted in Stat3 mutant mice with AD-HIES and in wild-type mice subjected to small-molecule STAT3 inhibition. Histamine skin prick test responses were diminished in patients with AD-HIES. Human umbilical vein endothelial cells derived from patients with AD-HIES or treated with a STAT3 inhibitor did not signal properly through Src or cause appropriate dissolution of the adherens junctions made up of the proteins vascular endothelial-cadherin and ß-catenin. Furthermore, we found that diminished STAT3 target microRNA17-92 expression in human umbilical vein endothelial cells from patients with AD-HIES is associated with increased phosphatase and tensin homolog (PTEN) expression, which inhibits Src, and increased E2F transcription factor 1 expression, which regulates ß-catenin cellular dynamics. CONCLUSIONS: These data demonstrate that STAT3-dependent transcriptional activity regulates critical components for the architecture and functional dynamics of endothelial junctions, thus permitting vascular permeability.

Inflammatory endotypes of chronic rhinosinusitis based on cluster analysis of biomarkers.

BACKGROUND: Current phenotyping of chronic rhinosinusitis (CRS) into chronic rhinosinusitis with nasal polyps (CRSwNP) and chronic rhinosinusitis without nasal polyps (CRSsNP) might not adequately reflect the pathophysiologic diversity within patients with CRS. OBJECTIVE: We sought to identify inflammatory endotypes of CRS. Therefore we aimed to cluster patients with CRS based solely on immune markers in a phenotype-free approach. Secondarily, we aimed to match clusters to phenotypes. METHODS: In this multicenter case-control study patients with CRS and control subjects underwent surgery, and tissue was analyzed for IL-5, IFN-γ, IL-17A, TNF-α, IL-22, IL-1ß, IL-6, IL-8, eosinophilic cationic protein, myeloperoxidase, TGF-ß1, IgE, Staphylococcus aureus enterotoxin-specific IgE, and albumin. We used partition-based clustering. RESULTS: Clustering of 173 cases resulted in 10 clusters, of which 4 clusters with low or undetectable IL-5, eosinophilic cationic protein, IgE, and albumin concentrations, and 6 clusters with high concentrations of those markers. The group of IL-5-negative clusters, 3 clusters clinically resembled a predominant chronic rhinosinusitis without nasal polyps (CRSsNP) phenotype without increased asthma prevalence, and 1 cluster had a TH17 profile and had mixed CRSsNP/CRSwNP. The IL-5-positive clusters were divided into a group with moderate IL-5 concentrations, a mixed CRSsNP/CRSwNP and increased asthma phenotype, and a group with high IL-5 levels, an almost exclusive nasal polyp phenotype with strongly increased asthma prevalence. In the latter group, 2 clusters demonstrated the highest concentrations of IgE and asthma prevalence, with all samples expressing Staphylococcus aureus enterotoxin-specific IgE. CONCLUSION: Distinct CRS clusters with diverse inflammatory mechanisms largely correlated with phenotypes and further differentiated them and provided a more accurate description of the inflammatory mechanisms involved than phenotype information only.

Neuro-immune interactions in chemical-induced airway hyperreactivity.

Asthma may be induced by chemical sensitisers, via mechanisms that are still poorly understood. This type of asthma is characterised by airway hyperreactivity (AHR) and little airway inflammation. Since potent chemical sensitisers, such as toluene-2,4-diisocyanate (TDI), are also sensory irritants, it is suggested that chemical-induced asthma relies on neuro-immune mechanisms.We investigated the involvement of transient receptor potential channels (TRP) A1 and V1, major chemosensors in the airways, and mast cells, known for their ability to communicate with sensory nerves, in chemical-induced AHR.In vitro intracellular calcium imaging and patch-clamp recordings in TRPA1- and TRPV1-expressing Chinese hamster ovarian cells showed that TDI activates murine TRPA1, but not TRPV1. Using an in vivo model, in which an airway challenge with TDI induces AHR in TDI-sensitised C57Bl/6 mice, we demonstrated that AHR does not develop, despite successful sensitisation, in Trpa1 and Trpv1 knockout mice, and wild-type mice pretreated with a TRPA1 blocker or a substance P receptor antagonist. TDI-induced AHR was also abolished in mast cell deficient Kit(Wsh) (/Wsh) mice, and in wild-type mice pretreated with the mast cell stabiliser ketotifen, without changes in immunological parameters.These data demonstrate that TRPA1, TRPV1 and mast cells play an indispensable role in the development of TDI-elicited AHR.

Estrogen increases the severity of anaphylaxis in female mice through enhanced endothelial nitric oxide synthase expression and nitric oxide production.

BACKGROUND: Clinical observations suggest that anaphylaxis is more common in adult women compared with adult men, although the mechanistic basis for this sex bias is not well understood. OBJECTIVES: We sought to document sex-dependent differences in a mouse model of anaphylaxis and explore the role of female sex hormones and the mechanisms responsible. METHODS: Passive systemic anaphylaxis was induced in female and male mice by using histamine, as well as IgE or IgG receptor aggregation. Anaphylaxis was assessed by monitoring body temperature, release of mast cell mediators and/or hematocrit, and lung weight as a measure of vascular permeability. A combination of ovariectomy, estrogen receptor antagonism, and estrogen administration techniques were used to establish estrogen involvement. RESULTS: Anaphylactic responses were more pronounced in female than male mice. The enhanced severity of anaphylaxis in female mice was eliminated after pretreatment with an estrogen receptor antagonist or ovariectomy but restored after administration of estradiol in ovariectomized mice, demonstrating that the sex-specific differences are due to the female steroid estradiol. Estrogen did not affect mast cell responsiveness or anaphylaxis onset. Instead, it increased tissue expression of endothelial nitric oxide synthase (eNOS). Blockage of NOS activity with the inhibitor L-NG-nitroarginine methyl ester or genetic eNOS deficiency abolished the sex-related differences. CONCLUSION: Our study defines a contribution of estrogen through its regulation of eNOS expression and nitric oxide production to vascular hyperpermeability and intensified anaphylactic responses in female mice, providing additional mechanistic insights into risk factors and possible implications for clinical management in the further exploration of human anaphylaxis.

Capsaicin treatment reduces nasal hyperreactivity and transient receptor potential cation channel subfamily V, receptor 1 (TRPV1) overexpression in patients with idiopathic rhinitis.

BACKGROUND: Idiopathic rhinitis (IR) is a prevalent condition for which capsaicin nasal spray is the most effective treatment. However, the mechanisms underlying IR and the therapeutic action of capsaicin remain unknown. OBJECTIVE: We sought to investigate the molecular and cellular bases of IR and the therapeutic action of capsaicin. METHODS: Fourteen patients with IR and 12 healthy control subjects (HCs) were treated with intranasal capsaicin. The therapeutic effect was assessed in patients with IR by using visual analog scale and therapeutic response evaluation scores, and nasal hyperreactivity was evaluated by means of cold dry air provocation. Nasal samples served to measure the levels of neuromediators and expression of chemosensory cation channels, protein gene product 9.5 (PGP 9.5), and the mast cell marker c-kit. The effects of capsaicin were also tested in vitro on human nasal epithelial cells and mast cells. RESULTS: Patients with IR had higher baseline transient receptor potential cation channel subfamily V, receptor 1 (TRPV1) expression in the nasal mucosa and higher concentrations of substance P (SP) in nasal secretions than HCs. Symptomatic relief was observed in 11 of 14 patients with IR after capsaicin treatment. Expression of TRPV1; transient receptor potential cation channel subfamily M, receptor 8 (TRPM8); and PGP 9.5 was only reduced in patients with IR after capsaicin treatment. Capsaicin did not alter c-KIT expression or nasal epithelial morphology in patients with IR and HCs nor did it induce apoptosis or necrosis in cultured human nasal epithelial cells and mast cells. CONCLUSION: IR features an overexpression of TRPV1 in the nasal mucosa and increased SP levels in nasal secretions. Capsaicin exerts its therapeutic action by ablating the TRPV1-SP nociceptive signaling pathway in the nasal mucosa.

Crucial role of transient receptor potential ankyrin 1 and mast cells in induction of nonallergic airway hyperreactivity in mice.

RATIONALE: Airway hyperreactivity (AHR) is a key feature of bronchial asthma, and inhalation of irritants may facilitate development of nonallergic AHR. Swimmers exposed to hypochlorite (ClO(-))-containing water show a higher risk of developing AHR. We developed a mouse model in which instillation of ClO(-) before ovalbumin (OVA) induces AHR without bronchial inflammatory cells. OBJECTIVES: To investigate the mechanisms of ClO(-)-OVA-induced nonallergic AHR. METHODS: The involvement of the transient receptor potential ankyrin (TRPA)1 channel was checked in vivo by the use of TRPA1(-/-) mice and in vitro by Ca(2+) imaging experiments. The role of substance P (SP) was investigated by pretreating animals with the receptor antagonist RP67580, by replacing ClO(-) with SP in vivo, and by immunofluorescent staining of large airways of exposed mice. The role of mast cells was evaluated by exposing mast cell-deficient Kit(Wh)/Kit(Wsh) mice to ClO(-)-OVA with or without mast cell reconstitution. MEASUREMENTS AND MAIN RESULTS: ClO(-)-OVA did not induce AHR in TRPA1(-/-) mice, and ClO(-) generates a Ca(2+) influx in TRPA1-transfected cells. Pretreatment with RP67580 reduces ClO(-)-OVA-induced AHR, although no increased SP expression was shown in the airways. SP-OVA exposure resulted in the same AHR as induced by ClO(-)-OVA. Kit(Wsh)/Kit(Wsh) mice did not develop AHR in response to ClO(-)-OVA unless they were reconstituted with bone marrow-derived mast cells. CONCLUSIONS: Induction of AHR by exposure to ClO(-)-OVA depends on a neuroimmune interaction that involves TRPA1-dependent stimulation of sensory neurons and mast cell activation.

IgA-producing B cells in lung homeostasis and disease.

Immunoglobulin A (IgA) is the most abundant Ig in mucosae where it plays key roles in host defense against pathogens and in mucosal immunoregulation. Whereas intense research has established the different roles of secretory IgA in the gut, its function has been much less studied in the lung. This review will first summarize the state-of-the-art knowledge on the distribution and phenotype of IgA+ B cells in the human lung in both homeostasis and disease. Second, it will analyze the studies looking at cellular and molecular mechanisms of homing and priming of IgA+ B cells in the lung, notably following immunization. Lastly, published data on observations related to IgA and IgA+ B cells in lung and airway disease such as asthma, cystic fibrosis, idiopathic pulmonary fibrosis, or chronic rhinosinusitis, will be discussed. Collectively it provides the state-of-the-art of our current understanding of the biology of IgA-producing cells in the airways and identifies gaps that future research should address in order to improve mucosal protection against lung infections and chronic inflammatory diseases.