IntroductionAdvances in antiretroviral therapy (ART) have substantially improved the lives of people with HIV (PWH) and reduced HIV acquisition through pre-exposure prophylaxis (PrEP). However, the long-term effect of ART on the physiological state of cells remains poorly understood and PWH are currently suffering from a disproportionate burden of non-AIDS comorbidities, including lung diseases.MethodsGiven the central function of alveolar macrophages (AM) in pulmonary immunity, we evaluated the impact of ART on AM of PWH and people on PrEP using a systems immunology approach.ResultsWe showed that continuous ART induces a progressive senescence-like pro-inflammatory state in AM characterized by increased constitutive epigenetic and transcriptomic priming of genes involved in cell-cycle arrest and senescence. At the AM single nucleus level, we discovered a coordinated gene regulatory network linking key pro-inflammatory transcription factors to the alterations induced by ART. The senescence ART-linked changes were strongly dependent on the duration of ART and irrespective of HIV infection. A secondary time independent ART-effect was observed for interferon signaling which impaired the AM response to ex vivo challenge with SARS-CoV-2.DiscussionOur data indicated that continuous ART promoted a dysregulated physiological state in AM. The results of our study advocate for optimized or adjuvant therapies to mitigate potential long-term adverse ART-effects.

Advances in antiretroviral therapy (ART) have substantially improved the lives of people with HIV (PWH) and reduced HIV acquisition through pre-exposure prophylaxis (PrEP). However, the long-term effect of ART on the physiological state of cells remains poorly understood. Despite the success of ART in preventing the progression of HIV infection to AIDS, PWH are suffering from a disproportional burden of non-AIDS comorbidities, including lung diseases. Given the central function of alveolar macrophages (AM) in pulmonary immunity, we evaluated the impact of time on ART on AM of PWH and people on PrEP. Employing a retrospective cross-sectional design, we showed that ART imprinted a pro-inflammatory and senescence-like epigenetic and transcriptomic state on AM. This effect of ART was detected irrespective of HIV infection. Increased epigenetic priming and gene expression of cell cycle arrest markers such as CDKN1A (p21), senescence associated secretory phenotype (SASP) genes, e.g. IL6R and CXCL8, and transcription factors subunits of the AP-1 family were a hallmark of ART exposure. The ART-linked epigenetic and transcriptomic changes were strongly dependent on the duration of ART for both the PWH and PrEP groups and consistent with dysregulated AM function. SASP contributes to the pathophysiology of multiple lung diseases such as COPD, pulmonary fibrosis, and asthma. Combined, our data suggested that long-term ART contributes to age-related pulmonary comorbidities in PWH. Given the strong correlation with time on ART and adverse effects in PWH, it is possible that long-term PrEP may result in similar clinical outcomes. While PrEP is critically important for preventing HIV acquisition in the most vulnerable populations, our study advocates for adjuvant therapies and improved drug design to prevent or mitigate potential long-term adverse effects of PrEP. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by grant 487046 from the Canadian Institutes of Health Research (CIHR). This research was supported through a resource allocation in the Cedar high performance computing cluster by Compute Canada and WestGrid. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was approved by the Research Ethics Board of the McGill University Health Center (MUHC) (MP-CUSM-15-406). All participants signed a written informed consent and were recruited at the McGill University Health Centre (MUHC, Montreal, Canada). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data used for the present study are available in GEO accession number GSE165709 or additional new data are available upon reasonable request to the authors

1Novartis Pharmaceuticals Canada Inc., Dorval, Quebec, Canada; 2Novartis Healthcare Private Limited, Hyderabad, India; 3Novartis Pharma AG, Basel, Switzerland; 4McGill University, Montreal, Quebec, Canada Purpose: We evaluated the cost-effectiveness of high-dose indacaterol acetate (IND)/glycopyrronium bromide (GLY)/mometasone furoate (MF) (150/50/160 μg, once daily) compared with high-dose salmeterol/fluticasone (SAL/FLU; 50/500 μg, twice daily)+tiotropium (TIO; 5 μg, once daily) (SAL/FLU+TIO) and with high-dose SAL/FLU (50/500 μg, twice daily) for the treatment of inadequately controlled moderate-to-severe asthma. Patients and Methods: A Markov model estimated the incremental cost-effectiveness ratio of treatment with high-dose IND/GLY/MF compared with SAL/FLU+TIO and high-dose IND/GLY/MF compared with SAL/FLU. The model included three health states (day-to-day symptoms without exacerbations, day-to-day symptoms with exacerbations, and death) with a 4-week cycle length. A lifetime time horizon was used. Exacerbation rates and utility values were derived from ARGON and IRIDIUM clinical trials. Canadian dollars (CAD$, 2020) were applied. Results: IND/GLY/MF was the less costly and more effective treatment strategy compared with SAL/FLU+TIO and SAL/FLU in the base-case analyses. IND/GLY/MF had lower costs (CAD $33,501 versus CAD $50,907) and higher quality-adjusted life-years (QALYs) (18.37 versus 18.06 QALYs) compared with SAL/FLU+TIO. Compared with SAL/FLU, IND/GLY/ MF had lower costs (CAD $33,408 versus CAD $36,577) and higher QALYs (19.33 versus 19.04 QALYs). IND/GLY/MF was the most cost-effective option in all scenarios tested. Conclusion: IND/GLY/MF was cost-effective at a willingness-to-pay threshold of CAD $50,000/QALY in patients with uncontrolled, moderate-to-severe asthma versus SAL/FLU +TIO and SAL/FLU in the base case and all scenarios tested.

SESSION TITLE: Allergy and Airway Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Bronchial thermoplasty (BT) is a non-pharmacologic, device-based treatment for subjects ≥18 years with severe persistent asthma not well controlled with inhaled corticosteroids (ICS) and long-acting beta-agonists (LABA). The “Post-FDA Approval Clinical Trial Evaluating BT in Severe Persistent Asthma (PAS2)“ study collects follow-up data for subjects undergoing BT treatment with the AlairTM BT System. Here, we report results for major endpoints to 5 years of follow-up. METHODS: The PAS2 study is a prospective, open-label, observational, multi-center trial at US and Canadian centers. Subjects 18-65 years taking ICS ≥1000μg/day (beclomethasone or equivalent) and LABA ≥80μg/day (salmeterol or equivalent) were enrolled. Additional inclusion criteria were: pre-bronchodilator FEV1 ≥60% predicted, non-smoker for ≥1 year (<10 pack/years if former smoker), ≥2 days with asthma symptoms in the last 4 weeks, AQLQ ≤6.25, and in the 12 months prior to BT treatment have ≤2 hospitalizations, ≤3 lower respiratory tract infections, and ≤3 severe exacerbations. Subjects diagnosed with other severe respiratory diseases were excluded. Baseline demographics were recorded. We examined healthcare utilization (severe exacerbations, hospitalization, and ER visits), spirometry (FEV1 and FVC), and medication usage through 5 years post-therapy. Safety data for the treatment and post-treatment periods was also collected. RESULTS: 284 subjects were enrolled at 27 centers; 279 subjects had at least 1 of 3 BT procedures; 271 subjects had all 3 BT procedures. At baseline subjects (64.5% female) had mean age 45.7 years, mean BMI 32.2kg/m2, and mean AQLQ of 4.03. 227 returned for their 5-year follow-up. Reductions in healthcare utilization observed post-BT persisted to the 5-year follow-up. The percentages of subjects with severe exacerbations at 12 months prior to BT and 1-5 years post-BT were 78%, 50%, 47%, 47%, 44%, and 43%, respectively. Similar patterns were seen for hospitalizations and ER visits for asthma. Mean ICS dose dropped from 2272μg/day at baseline to 1910-2080μg/day for years 1-5. The percentage of patients using maintenance OCS was 19.4% at baseline but was reduced to 8.1%-10.7% during years 1-5. Omalizumab usage dropped from 16% at baseline to 11% at year 5; however, use of mepolizumab and benralizumab increased over the study period to 6.6% and 0.9%, respectively, at 5 years. FEV1 and FVC remained stable after BT treatment. Data also confirmed the safety of the BT procedure to 5 years. CONCLUSIONS: The PAS2 study data indicates that improvements in asthma control with respect to severe exacerbations, hospitalizations and ER visits after BT are durable out to 5 years, and reductions in ICS and maintenance OCS usage are maintained. CLINICAL IMPLICATIONS: Treatment with BT leads to sustained improvements in asthma control and reductions in corticosteroid maintenance medications over 5 years. DISCLOSURES: Speaker/Speaker's Bureau relationship with GlaxoSmithKline Please note: $20001 - $100000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Honoraria Consultant relationship with Circulogene Please note: $5001 - $20000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Consulting fee Speaker/Speaker's Bureau relationship with Boehringer Ingelheim Please note: $5001 - $20000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Honoraria Consultant relationship with Auris Health, Inc. Please note: $5001 - $20000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Consulting fee Consultant relationship with Vercyte Inc. Please note: $20001 - $100000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Consulting fee Consultant relationship with Veran Technologies Please note: $20001 - $100000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Consulting fee Consultant relationship with Biodesix, Inc. Please note: $5001 - $20000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Consulting fee Consultant relationship with Pinnacle Biologics, Inc. Please note: $5001 - $20000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Consulting fee Consultant relationship with Medtronic Please note: $20001 - $100000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Consulting fee Consultant relationship with Boston Scientific Please note: $20001 - $100000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Consulting fee Speaker/Speaker's relationship with Forest Laboratories Please note: $20001 - $100000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with Sunovion Pharmaceuticals Inc. Please note: $5001 - $20000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Honoraria Consultant relationship with INTUITIVE SURGICAL, INC. Please note: $1001 - $5000 Added 05/23/2020 by Sandeep Bansal, source=Web Response, value=Travel Fee Speaker/Speaker's Bureau relationship with Genentech Please note: $1-$1000 Added 05/21/2020 by Geoffrey Chupp, source=Web Response, value=Honoraria Removed 05/26/2020 by Geoffrey Chupp, source=Web Response Consultant relationship with AstraZeneca Please note: >$100000 Added 05/28/2020 by Geoffrey Chupp, source=Web Response, value=Consulting fee Consultant relationship with Genentech Please note: $20001 - $100000 Added 05/28/2020 by Geoffrey Chupp, source=Web Response, value=Consulting fee Consultant relationship with Genzyme Corporation Please note: $5001 - $20000 Added 05/28/2020 by Geoffrey Chupp, source=Web Response, value=Consulting fee Consultant relationship with Novartis Please note: $5001 - $20000 Added 05/28/2020 by Geoffrey Chupp, source=Web Response, value=Consulting fee Consultant relationship with Circassia Please note: $1001 - $5000 Added 05/28/2020 by Geoffrey Chupp, source=Web Response, value=Consulting fee Consultant relationship with Boehringer Ingelheim Please note: $1001 - $5000 Added 05/28/2020 by Geoffrey Chupp, source=Web Response, value=Consulting fee Consultant relationship with GlaxoSmithKline Please note: $1-$1000 Added 05/28/2020 by Geoffrey Chupp, source=Web Response, value=Consulting fee Consultant relationship with AstraZeneca Please note: $1001 - $5000 Added 05/22/2020 by Mark Dransfield, source=Web Response, value=Personal fees Consultant relationship with GSK Please note: $5001 - $20000 Added 05/22/2020 by Mark Dransfield, source=Web Response, value=Personal fees Consultant relationship with AstraZeneca Please note: $5001 - $20000 Added 05/23/2020 by Mark Dransfield, source=Web Response, value=Consulting fee Consultant relationship with GSK Please note: $20001 - $100000 Added 05/23/2020 by Mark Dransfield, source=Web Response, value=Consulting fee Consultant relationship with PneumRx/BTG Please note: $1001 - $5000 Added 05/23/2020 by Mark Dransfield, source=Web Response, value=Consulting fee Consultant relationship with Quark Please note: $5001 - $20000 Added 05/23/2020 by Mark Dransfield, source=Web Response, value=Consulting fee Consultant relationship with Pulmonx Please note: $1-$1000 Added 05/23/2020 by Mark Dransfield, source=Web Response, value=Travel Consultant relationship with Pulmonx Please note: $1-$1000 Added 05/23/2020 by Mark Dransfield, source=Web Response, value=Travel Removed 05/23/2020 by Mark Dransfield, source=Web Response Consultant relationship with Noah Medical Please note: $1001 - $5000 Added 05/29/2020 by J Ferguson, source=Web Response, value=Consulting fee Scientific Medical Advisor relationship with VIDA Dianostics Please note: $1-$1000 Added 05/29/2020 by J Ferguson, source=Web Response, value=Consulting fee Advisory Committee Member relationship with PPDI Please note: $1-$1000 Added 05/29/2020 by J Ferguson, source=Web Response, value=Consulting fee no disclosure on file for Andrew Haas; Consultant relationship with Auris Please note: >$100000 by D Hogarth, source=Web Response, value=Ownership interest Consultant relationship with Body Vision Please note: $20001 - $100000 by D Hogarth, source=Web Response, value=Ownership interest Consultant relationship with Bronchisense Please note: $5001 - $20000 by D Hogarth, source=Web Response, value=Ownership interest Consultant relationship with Eolo Please note: $20001 - $100000 by D Hogarth, source=Web Response, value=Ownership interest Consultant relationship with LX-Medical Please note: $5001 - $20000 by D Hogarth, source=Web Response, value=Ownership interest Owner/Founder relationship with Med-Opsys Please note: $20001 - $100000 by D Hogarth, source=Web Response, value=Ownership interest Consultant relationship with Preora Please note: $5001 - $20000 by D Hogarth, source=Web Response, value=Ownership interest Consultant relationship with VIDA Please note: $1001 - $5000 by D Hogarth, source=Web Response, value=Ownership interest Removed 05/30/2020 by D Hogarth, source=Web Response Consultant relationship with Viomics Please note: $20001 - $100000 by D Hogarth, source=Web Response, value=Ownership interest Removed 05/30/2020 by D Hogarth, source=Web Response Consultant relationship with Eon Please note: $20001 - $100000 by D Hogarth, source=Web Response, value=Ownership interest Advisory Committee Member relationship with Ambu Please note: $1001 - $5000 by D Hogarth, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with Biodesix Please note: $20001 - $100000 by D Hogarth, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with Boston Scientfic Please note: $5001 - $20000 Added 05/30/2020 by D Hogarth, source=Web Response, value=Honoraria Consultant relationship with Broncus Please note: $1-$1000 by D Hogarth, source=Web Response, value=Consulting fee Consultant relationship with CSL Please note: $1-$1000 by D Hogarth, source=Web Response, value=Consulting fee Consultant relationship with Gala Please note: $1001 - $5000 by D Hogarth, source=Web Response, value=Consulting fee Consultant relationship with Intuitive Please note: $1001 - $5000 by D Hogarth, source=Web Response, value=Consulting fee Consultant relationship with Level-Ex Please note: $1001 - $5000 by D Hogarth, source=Web Response, value=Consulting fee Speaker/Speaker's Bureau relationship with Medtronic Please note: $5001 - $20000 by D Hogarth, source=Web Response, value=Honoraria Consultant relationship with Oncocyte Please note: $1001 - $5000 by D Hogarth, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with Veracyte Please note: $20001 - $100000 by D Hogarth, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with astra zeneca Please note: $20001 - $100000 by D Hogarth, source=Web Response, value=Honoraria Speaker/Speaker's Bureau relationship with B.I. 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S28463 (S28), a ligand for Toll-like receptor 7/8, has been shown to have antiinflammatory properties in rodent models of allergic asthma. The principle goal of this study was to assess whether these antiinflammatory effects can also be observed in a nonhuman primate (NHP) model of allergic asthma. NHPs were sensitized then challenged with natural allergen, Ascaris suum extract. The animals were treated with S28 orally before each allergen challenge. The protective effect of S28 in NHPs was assessed by measuring various asthma-related phenotypes. We also characterized the metabolomic and proteomic signatures of the lung environment and plasma to identify markers associated with the disease and treatment. Our data demonstrate that clinically relevant parameters, such as wheal and flare response, blood IgE levels, recruitment of white blood cells to the bronchoalveolar space, and lung responsiveness, are decreased in the S28-treated allergic NHPs compared with nontreated allergic NHPs. Furthermore, we also identified markers that can distinguish allergic from nonallergic or allergic and drug-treated NHPs, such as metabolites, phosphocreatine and glutathione, in the plasma and BAL fluid, respectively; and inflammatory cytokines, IL-5 and IL-13, in the bronchoalveolar lavage fluid. Our preclinical study demonstrates that S28 has potential as a treatment for allergic asthma in primate species closely related to humans. Combined with our previous findings, we demonstrate that S28 is effective in different models of asthma and in different species, and has the antiinflammatory properties clinically relevant for the treatment of allergic asthma.

The heterogeneous nature of asthma has been understood for decades, but the precise categorization of asthma has taken on new clinical importance in the era of specific biologic therapy. The simple categories of allergic and non-allergic asthma have given way to more precise phenotypes that hint at underlying biologic mechanisms of variable airflow limitation and airways inflammation. Understanding these mechanisms is of particular importance for the approximately 10% of patients with severe asthma. Biomarkers that aid in phenotyping allow physicians to "personalize" treatment with targeted biologic agents. Unfortunately, testing for these biomarkers is not routine in patients whose asthma is refractory to standard therapy. Scientific advances in the recognition of sensitive and specific biomarkers are steadily outpacing the clinical availability of reliable and non-invasive assessment methods designed for the prompt and specific diagnosis, classification, treatment, and monitoring of severe asthma patients. This article provides a practical overview of current biomarkers and testing methods for prompt, effective management of patients with severe asthma that is refractory to standard therapy.

RATIONALE: While severe asthma affects approximately 5% of all individuals with asthma, this small minority of individuals accounts for a large proportion of the asthma-related costs. Greater understanding of the pathophysiology of asthma combined with the emergence of novel biologic therapies for severe asthma supported the need for a thorough review of the diagnosis, investigation, phenotyping, and management of severe asthma.OBJECTIVES: We aimed to propose a practical approach to distinguish uncontrolled asthma due to inadequate asthma management from severe asthma despite optimal asthma management. Moreover, based on emerging scientific evidence, we sought to provide guidance for characterizing individuals with severe asthma and considering a phenotype-specific management. We also aimed to review other novel new potential therapeutic approaches.METHODS: We systematically reviewed the relevant literature focusing on randomized controlled trials and when available, systematic reviews of randomized controlled trials. The proposed key messages, based on scientific evidence and expert opinion, were agreed upon by unanimous consensus.MAIN RESULTS: We defined severe asthma and outlined its significant impact from the societal and patient perspectives. We outlined a practical approach to distinguish severe from uncontrolled but not severe asthma, based on stepwise investigation and management of potential reasons for uncontrolled asthma. After reviewing the current evidence we concluded that: 1) Several biomarkers (e.g. sputum or blood eosinophil count, total IgE, or FeNO) can help identify potential responders to new therapeutic options; 2) Tiotropium may be considered as an add-on therapy for individuals 12 years of age and over with severe asthma uncontrolled despite combination ICS/LABA therapy; 3) The chronic use of macrolides may decrease asthma exacerbations in individuals 18 years of age and over with severe asthma independent of their inflammatory profile; 4) Children aged 6 years and older and adults who are sensitized to at least one relevant perennial allergen and who remain poorly controlled asthmatics despite high dose ICS and a second controller can benefit from the addition of anti-IgE therapy to reduce asthma exacerbations; due to the known risk of side effects associated with high-dose ICS in children, omalizumab should also be considered in children and adolescents who repeatedly exacerbate or have poor control when therapy is stepped down from high-dose to moderate-dose ICS and at least one other controller; 5) Anti-IL5 therapies may be considered for adults 18 years of age and over with severe eosinophilic asthma who experience recurrent asthma exacerbations in spite of high doses of ICS in addition to at least one other controller; and 6) Although bronchial thermoplasty has shown a decrease in asthma exacerbations in one study, its role in the treatment of severe asthma remains uncertain.CONCLUSIONS: After reviewing existing and emerging therapies for severe asthma, we developed key messages for phenotyping individuals with severe asthma and suggested phenotype-specific targeted therapies. We highlighted gaps in knowledge in the pathophysiology of severe asthma, the identification of responders, and the assessment of the efficacy of novel therapies that should be targeted by future research.

Endobronchial tumour embolism is a rare cause of acute central airway obstruction. It is primarily reported during pneumonectomy, and the outcome is frequently fatal. Successful management requires the urgent removal of tumour with rigid or flexible bronchoscopy. We present the case of a 62‐year‐old woman with poorly differentiated non‐small cell lung cancer (NSCLC), referred to our institution for Nd:YAG laser photoresection of endobronchial tumour completely obstructing the right mainstem bronchus (RMSB). Soon after admission, our patient developed critical hypoxemia, rapidly followed by cardiac arrest. Bronchoscopy was urgently performed and revealed a necrotic tumour occluding the left mainstem bronchus (LMSB), with some residual tumour and clot at the RMSB. The tumour acutely obstructing the LMSB was successfully extracted using a foreign body retrieval basket and large flexible biopsy forceps via a large (therapeutic) flexible bronchoscope. Ventilation immediately improved, with the return of a pulse, and the patient was successfully extubated the next day. Pathology of the tumour embolism revealed NSCLC with necrosis and an adherent clot. Here, we review 16 published reports of endobronchial tumour embolism in relation to our case.

ABSTRACT RATIONALE: While severe asthma affects approximately 5% of all individuals with asthma, this small minority of individuals accounts for a large proportion of the asthma-related costs. Greater understanding of the pathophysiology of asthma combined with the emergence of novel biologic therapies for severe asthma supported the need for a thorough review of the diagnosis, investigation, phenotyping, and management of severe asthma. OBJECTIVES: We aimed to propose a practical approach to distinguish uncontrolled asthma due to inadequate asthma management from severe asthma despite optimal asthma management. Moreover, based on emerging scientific evidence, we sought to provide guidance for characterizing individuals with severe asthma and considering a phenotype-specific management. We also aimed to review other novel new potential therapeutic approaches. METHODS: We systematically reviewed the relevant literature focusing on randomized controlled trials and when available, systematic reviews of randomized controlled trials. The proposed key messages, based on scientific evidence and expert opinion, were agreed upon by unanimous consensus. MAIN RESULTS: We defined severe asthma and outlined its significant impact from the societal and patient perspectives. We outlined a practical approach to distinguish severe from uncontrolled but not severe asthma, based on stepwise investigation and management of potential reasons for uncontrolled asthma. After reviewing the current evidence we concluded that: 1) Several biomarkers (e.g. sputum or blood eosinophil count, total IgE, or FeNO) can help identify potential responders to new therapeutic options; 2) Tiotropium may be considered as an add-on therapy for individuals 12 years of age and over with severe asthma uncontrolled despite combination ICS/LABA therapy; 3) The chronic use of macrolides may decrease asthma exacerbations in individuals 18 years of age and over with severe asthma independent of their inflammatory profile; 4) Children aged 6 years and older and adults who are sensitized to at least one relevant perennial allergen and who remain poorly controlled asthmatics despite high dose ICS and a second controller can benefit from the addition of anti-IgE therapy to reduce asthma exacerbations; due to the known risk of side effects associated with high-dose ICS in children, omalizumab should also be considered in children and adolescents who repeatedly exacerbate or have poor control when therapy is stepped down from high-dose to moderate-dose ICS and at least one other controller; 5) Anti-IL5 therapies may be considered for adults 18 years of age and over with severe eosinophilic asthma who experience recurrent asthma exacerbations in spite of high doses of ICS in addition to at least one other controller; and 6) Although bronchial thermoplasty has shown a decrease in asthma exacerbations in one study, its role in the treatment of severe asthma remains uncertain. CONCLUSIONS: After reviewing existing and emerging therapies for severe asthma, we developed key messages for phenotyping individuals with severe asthma and suggested phenotype-specific targeted therapies. We highlighted gaps in knowledge in the pathophysiology of severe asthma, the identification of responders, and the assessment of the efficacy of novel therapies that should be targeted by future research. RÉSUMÉ JUSTIFICATION: Bien que l'asthme sévère touche environ 5 % des asthmatiques, une grande proportion des coûts liés à l'asthme est imputable à cette petite minorité. Une plus grande compréhension de la pathophysiologie de l'asthme, combinée à l'émergence de traitements biologiques novateurs pour l'asthme sévère, a rendu nécessaire la révision approfondie du diagnostic, de l'investigation, du phénotypage et de la prise en charge de l'asthme sévère. OBJECTIFS: Nous avions pour but de proposer une approche pratique pour distinguer l'asthme non contrôlé dû à une prise en charge inadéquate, de l'asthme sévère dépit d'une prise en charge optimale de l'asthme. De plus, à partir des données probantes scientifiques émergentes, nous avons cherché à donner des indications pour la caractérisation des personnes souffrant d'asthme sévère et envisager une prise en charge spécifique à leur phénotype. Nous avions aussi pour but d'examiner d'autres approches thérapeutiques novatrices potentielles. MÉTHODES: Nous avons passé en revue la littérature pertinente de façon systématique, en mettant l'accent sur les essais contrôlés randomisés et, lorsqu'elles étaient disponibles, sur les revues systématiques d'essais contrôlés randomisés. PRINCIPAUX RÉSULTATS: Nous avons défini l'asthme sévère et décrit ses effets importants du point de vue sociétal et du point de vue du patient. Nous avons présenté une approche pratique afin de distinguer l'asthme sévère de l'asthme non contrôlé mais non sévère, fondée sur une investigation par étapes et la prise en charge des causes possibles de l'asthme non contrôlé. Après avoir examiné les données probantes disponibles, nous avons conclu que : 1) Plusieurs biomarqueurs (ex.: numération des éosinophiles dans les expectorations ou dans le sang, IgE totales ou de FeNO) peuvent aider à répertorier les répondeurs potentiels aux nouvelles options thérapeutiques; 2) Le tiotropium peut être envisagé en tant que traitement additionnel pour les individus âgés de 12 ans et plus souffrant d'asthme sévère non contrôlé malgré une thérapie associant les CSI et les ABAP; 3) L'usage chronique des macrolides peut diminuer les exacerbations de l'asthme chez les individus âgés de 18 ans et plus souffrant d'asthme sévère indépendamment de leur profil inflammatoire; 4) Les enfants âgés de six ans et plus et les adultes sensibilisés à au moins un allergène pérenne pertinent qui demeurent des asthmatiques mal contrôlés malgré une forte dose de CSI et un deuxième contrôleur peuvent bénéficier de l'ajout d'un traitement anti-IgE afin de réduire les exacerbations de l'asthme; en raison du risque connu d'effets secondaires associés à une dose élevée de CSI chez les enfants, l'omalizumab devrait aussi être envisagé chez les enfants et les adolescents qui souffrent d'exacerbations à répétition ou dont l'asthme est mal contrôlé, lorsque le traitement passe d'une forte dose d'ICS à une dose modérée d'ICS assortie d'au moins un autre contrôleur; 5) Les traitements par anti-IL5 peuvent être envisagés pour les adultes de 18 ans et plus souffrant d'asthme éosinophilique sévère qui sont aux prises avec des exacerbations de l'asthme récurrentes malgré des doses élevées d'ICS associées à au moins un autre contrôleur; et 6) Bien que la thermoplastie bronchique ait démontré une diminution des exacerbations de l'asthme dans une étude, son rôle dans le traitement de l'asthme sévère demeure incertain. CONCLUSION: Après avoir examiné les traitements existants et émergents pour l'asthme sévère, nous avons défini des messages-clés pour phénotyper les individus souffrant d'asthme sévère et suggérer des thérapies ciblées spécifiques au phénotype.

To the Editor: Asthma heterogeneity has been described by the nature and intensity of granulocytic infiltration into the airways [1, 2]. Sputum, endobronchial biopsies and bronchoalveolar lavage (BAL) sample different anatomical regions of the airways. Few studies have directly compared the inflammatory cell infiltrates in these regions within a large cohort of moderate–severe asthma patients using standard techniques. In the BOBCAT (Bronchoscopic exploratory research study Of Biomarkers in Corticosteroid-refractory AsThma) study, we sampled multiple airway compartments concurrently, enabling us to evaluate relationships between granulocytic infiltrates within and between compartments in a large cohort of moderate–severe adult asthma patients. This prospective multicentre observational study was conducted in four visits over a 4–6 week period, as described previously [3]. The patients included had moderate–severe persistent asthma (forced expiratory volume in 1 s (FEV1) 40–80% predicted and Asthma Control Questionnaire (ACQ) [4] score >1.5) and, within the past 5 years, evidence of >12% post-bronchodilator reversibility or a provocative concentration of methacholine causing a 20% decline in FEV1 ≤8 mg·mL−1 despite high-dose inhaled corticosteroid (ICS) (≥1000 μg·day−1 fluticasone propionate equivalent) with or without long-acting β2-adrenergic agonist therapy. Key exclusion criteria included initiation or increase in systemic steroid use 30 days prior to screening, chronic or recent (within the past 30 days) use of immunosuppressive therapies, or other active lung disease. Patients had a prior established diagnosis of moderate–severe asthma for ≥6 months prior to screening while receiving a stable dose regimen (>6 weeks) of a high-dose ICS. Allowed concomitant medications included leukotriene receptor antagonists and oral corticosteroids. 78 patients with confirmed moderate–severe asthma were enrolled at 18 sites; 67 (86%) completed the study. All patients had persistently impaired …

Background: Many asthmatic patients exhibit sputum eosinophilia associated with exacerbations. Benralizumab targets eosinophils by binding IL-5 receptor alpha, inducing apoptosis through antibody-dependent cell-mediated cytotoxicity.Objectives: We sought to evaluate the safety of benralizumab in adults with eosinophilic asthma and its effects on eosinophil counts in airway mucosal/submucosal biopsy specimens, sputum, bone marrow, and peripheral blood.Methods: In this multicenter, double-blind, placebo-controlled phase I study, 13 subjects were randomized to single-dose intravenous placebo or 1 mg/kg benralizumab (day 0; cohort 1), and 14 subjects were randomized to 3 monthly subcutaneous doses of placebo or 100 or 200 mg of benralizumab (days 0, 28, and 56; cohort 2). Cohorts 1 and 2 were consecutive.Results: The incidence of adverse events was similar between groups. No serious adverse events related to benralizumab occurred. In cohort 1 intravenous benralizumab produced a median decrease from baseline of 61.9% in airway mucosal eosinophil counts (day 28; placebo: +19.6%; P = .28), as well as an 18.7% decrease (day 21) in sputum and a 100% decrease (day 28) in blood counts. Eosinophils were not detectable in bone marrow of benralizumab-treated subjects (day 28, n = 4). In cohort 2 subcutaneous benralizumab demonstrated a combined (100 1 200 mg) median reduction of 95.8% in airway eosinophil counts (day 84; placebo, 46.7%; P = .06), as well as an 89.9% decrease (day 28) in sputum and a 100% decrease (day 84) in blood counts.Conclusion: Single-dose intravenous and multiple-dose subcutaneous benralizumab reduced eosinophil counts in airway mucosa/submucosa and sputum and suppressed eosinophil counts in bone marrow and peripheral blood. The safety profile supports further development. Additional studies are needed to assess the clinical benefit in asthmatic patients.

Neutrophilic inflammation plays an important role in lung tissue destruction occurring in many chronic pulmonary diseases. Neu-trophils can be recruited to sites of inflammation via the action of the cytokine IL-17. In this study, we report that IL-17RA and IL-17RC mRNA expression is significantly increased in asthmatic bronchoscopic biopsies and that these receptors are not only expressed on epithelial and inflammatory cells but also on endothelial cells. IL-17 potently stimulates lung microvascular endothelial cells to produce chemoattractants (CXCL8 and derivatives of the 5-lipoxygenase pathway) that selectively drive neutrophil but not lymphocyte chemotaxis. Moreover, IL-17 promotes endothelial activation by inducing the expression of endothelial adhesion markers (E-selectin, VCAM-1, and ICAM-1) in a p38 MAPK-dependent manner. This increased expression of adhesion molecules stimulates the trans-endothelial migration of neutrophils, as well as the transmigration of HT-29 colon carcinoma cells, suggesting a further role in promoting lung metastasis. Finally, IL-17 increased neutrophil adhesion to the endothelium in vivo as determined by intravital microscopy of mice cremaster muscle. Overall, our results demonstrate that IL-17 is a potent activator of the endothelium in vivo leading to neutrophil infiltration. Therefore, preventing neutrophil recruitment by blocking the action of IL-17 on endothelial cells may prove to be highly beneficial in diseases in which neutrophilic inflammation plays a key role. N eutrophilic inflammation of the airways is an important feature in respiratory diseases, including acute respiratory distress syndrome (1), chronic bronchitis (2), chronic obstructive pulmonary disease (2), and cystic fibrosis (CF) (3). Moreover, neutrophilic inflammation has also been reported in patients suffering from severe asthma (4, 5). Furthermore, diseases associated with neutrophilic inflammation are generally found to be poorly responsive to corticosteroids, a common and effective anti-inflammatory (6). Therefore, neutrophilic inflammation may be determinant in chronic lung tissue destruction, and understanding the mechanisms underlying the recruitment of neutrophils to inflammatory sites may shed light on new ways to prevent chronic lung diseases. Neutrophils can be attracted to the lungs from the circulation via the action of various chemoattractants including the metabolites of the 5-lipoxygenase (5-LO) pathway, leukotriene B 4 (7) and 5-oxo-6,8, 11,14-eicosatetraenoic acid (8), as well as members of the Cys-Xxx-Cys chemokine family, such as CXCL8 (also known as IL-8) (9). These mediators can be synthesized via the activation of both inflammatory and structural cells of the airways in response to various environmental cues. Dissecting the relationship between these environmental cues and the production of neutro-phil chemoattractants will …

To the Editor:Sputum examination in patients with asthma is a noninvasive method for assessment of airway inflammation.1Pin I. Gibson P.G. Kolendowicz R. Girgis-Gabardo A. Denburg J.A. Hargreave F.E. et al.Use of induced sputum cell counts to investigate airway inflammation in asthma.Thorax. 1992; 47: 25-29Crossref PubMed Scopus (828) Google Scholar Typically, expectorated or induced sputum in patients with asthma is rich in eosinophils, but variable inflammatory cell profiles have been reported,2Simpson J.L. Inflammatory subtypes in asthma: Assessment and identification using induced sputum.Respirology. 2006; 11: 54-61Crossref PubMed Scopus (682) Google Scholar prompting a classification with 4 phenotypes: eosinophilic, neutrophilic, mixed, and paucigranulocytic. These profiles might change with time,3D'Silva L. Cook R.J. Allen C.J. Hargreave F.E. Parameswaran K. Changing pattern of sputum cell counts during successive exacerbations of airway disease.Respir Med. 2007; 101: 2217-2220Abstract Full Text Full Text PDF PubMed Scopus (39) Google Scholar but the extent to which inflammatory patterns are conserved has not been extensively explored.The current study assesses the characteristics and stability of airway inflammation in subjects with moderate and severe asthma. Induced sputum was analyzed monthly for patients with severe disease and every 3 months for patients with moderate disease over 1 year. Respiratory physicians at 2 tertiary centers identified 37 patients who met the American Thoracic Society criteria for severe asthma.4Proceedings of the ATS Workshop on Refractory Asthma. Current understanding, recommendations, and unanswered questions.Am J Respir Crit Care Med. 2000; 162: 2341-2351Crossref PubMed Scopus (895) Google Scholar The subjects were participating in the Severe Asthma Program, which has been the subject of several previous publications.5Shannon J. Ernst P. Yamauchi Y. Olivenstein R. Lemiere C. Foley S. et al.Differences in airway cytokine profile in severe asthma compared to moderate asthma.Chest. 2008; 133: 420-426Crossref PubMed Scopus (180) Google Scholar Physicians also recruited 24 age- and sex-matched patients with moderate asthma.The subjects were taking 176 to 880 μg/d fluticasone (or equivalent) with or without β-agonists, a leukotriene receptor antagonist, or theophylline; used 2 or fewer steroid bursts in the previous year and none in the previous 3 months with less than 30 days of oral steroids in the previous 12 months; had an FEV1 of 70% or greater of predicted value and 90% or greater of personal best in previous 2 years; and had 1 or more unscheduled visits for asthma in the previous 12 months.The study was approved by the research ethics committee of each participating center. All subjects provided written informed consent, and their clinical characteristics are found in Table I.Table IClinical characteristicsSevere asthma∗All subjects were taking inhaled corticosteroids. (n = 37)Moderate asthma∗All subjects were taking inhaled corticosteroids. (n = 24)P valueAge (y)47.6 ± 11.7651.6 ± 10.2NSSex (M/F)21/1614/10NSFEV1 (% predicted)†Means ± SDs based on observations for all visits.66.6 ± 21.985.0 ± 12.2.0003Prebronchodilator FEV1/FVC ratio65.7 ± 11.973.1 ± 5.5.0058BMI (kg/m2)28.2 ± 6.127.2 ± 6.3NSSubjects with atopy‡Subjects underwent skin testing to 13 aeroallergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat, dog, horse, ragweed, grass mix, tree mix, weed mix, feather mix, and Alternaria, Aspergillus, and Cladosporium species). Histamine (10 mg/mL) and its diluent were used as positive and negative controls, respectively. A positive test result was set as the larger of 2 perpendicular diameters of greater than 3 mm of the control.31 (84%)21 (88%)NSDose of inhaled corticosteroid (μg/d)∗All subjects were taking inhaled corticosteroids.1,275 ± 324618 ± 325

BACKGROUND:Though several biologic factors have been suggested to play a role in the development and persistence of severe asthma, those associated with psychologic factors remain poorly understood. This study assessed levels of psychologic distress and a range of disease-relevant emotional and behavioral coping styles in patients with severe vs moderate asthma. METHODS:Eighty-four patients (50% women, mean [M] age 46 years) with severe (n = 42) and moderate (n = 42) asthma were recruited. Severe asthma was defined according to American Thoracic Society criteria. Patients underwent demographic and medical history interviews and pulmonary function and allergy testing. Patients also completed questionnaires measuring asthma symptoms and the Millon Behavioral Medicine Diagnostic Inventory, which assesses psychologic distress and emotional/behavioral coping factors that influence disease progression and treatment. RESULTS:After adjustment for covariates and applying a correction factor that reduced the significant P level to < .01, patients with severe vs moderate asthma reported experiencing more psychologic distress, including worse cognitive dysfunction (F = 6.72, P < .01) and marginally worse anxiety-tension (F = 4.02, P < .05). They also reported worse emotional coping (higher illness apprehension [F = 9.57, P < .01], pain sensitivity [F = 10.65, P < .01], future pessimism [F= 8.53, P < .01], and interventional fragility [F = 7.18, P < .01]), and marginally worse behavioral coping (more functional deficits [F = 5.48, P < .05] and problematic compliance [F = 4.32, P < .05]). CONCLUSIONS:Patients with severe asthma have more psychologic distress and difficulty coping with their disease, both emotionally and behaviorally, relative to patients with moderate asthma. Future treatment studies should focus on helping patients with severe asthma manage distress and cope more effectively with their illness, which may improve outcomes in these high-risk patients.

RATIONALE Airway remodeling in asthma comprises increased airway smooth muscle (ASM), an alteration linked to airway hyperresponsiveness and disease severity. Experimental studies showed that T cells adhere to ASM through vascular cell adhesion molecule-1 (VCAM-1) and drive ASM growth through direct contact between the T cells and smooth muscle alpha-actin (alpha-SMA)(+) cells. OBJECTIVES To support the hypothesis of a T-cell/alpha-SMA(+) cell contact mechanism of ASM remodeling in asthma, using bronchial biopsies. METHODS We performed quantitative morphology on T cells, proliferating cell nuclear antigen (PCNA), alpha-SMA, and VCAM-1 on biopsies from subjects with moderate and severe asthma and healthy control subjects. MEASUREMENTS AND MAIN RESULTS We demonstrate ASM cell proliferation and infiltration by T cells in proportion to severity in the subjects with asthma. T cells localized with alpha-SMA(+)PCNA(+) cells, suggesting direct intercellular contact and a relationship with alpha-SMA(+) cell proliferation. Furthermore, the subjects with asthma developed a proliferating compartment of subepithelial alpha-SMA(+), nonorganized airway contractile elements (NOACE), suggesting a phenotype gradient from undifferentiated cells to smooth muscle-like cells. T-cell juxtaposition events were also observed in this compartment and correlated to its mass. The subjects with asthma showed VCAM-1 expression in postcapillary venules and clusters of VCAM-1 immunoreactivity in ASM and NOACE, consistent with a role of VCAM-1 in T-cell/alpha-SMA(+) cell interaction. CONCLUSIONS T cells may induce alpha-SMA(+) cell proliferation through direct intercellular contact. NOACE may in part contribute to ASM growth through differentiation and translocation of alpha-SMA(+) cells. The findings support the role of the T cell in ASM remodeling in asthma.

To the Editor: Asthma affects approximately 8% of the adult population and as many as 20% of children worldwide.1Beasley R. Worldwide variation in prevalence of symptoms of asthma, allergic rhinoconjunctivitis, and atopic eczema: ISAAC.Lancet. 1998; 351: 1225-1232Abstract Full Text Full Text PDF PubMed Scopus (3335) Google Scholar Most of the studies have been conducted on patients with mild to moderate asthma and have shown airway inflammation to be associated with T-cell activation, eosinophil accumulation, and TH2-type cytokine production. Severe asthma represents 10% of the asthmatic population but has greater morbidity and mortality and uses a disproportionate amount of health care expenditures. Furthermore, the subpopulation of patients with severe asthma appears to manifest a different pattern of airway inflammation that is not associated with either classic TH1 or TH2 cells. For example, the neutrophil chemoattractant IL-8 is prominently expressed in the airways of such patients.2Ordoñez C.L. Shaughnessy T.E. Matthay M.A. Fahy J.V. Increased neutrophil numbers and IL-8 levels in airway secretions in acute severe asthma: clinical and biologic significance.Am J Respir Crit Care Med. 2000; 161: 1185-1190Crossref PubMed Scopus (390) Google Scholar These observations suggest the possibility of a role for other T-cell subsets. Regulatory T cells have been shown to be reduced in severe asthma, but a recently described subset of T cells, the TH17 cell, has not been investigated to date. TH17 cells produce a number of cytokines, but in particular IL-17A and IL-17F.3Molet S.M. Hamid Q.A. Hamilos D.L. IL-11 and IL-17 expression in nasal polyps: relationship to collagen deposition and suppression by intranasal fluticasone propionate.Laryngoscope. 2003; 113: 1803-1812Crossref PubMed Scopus (91) Google Scholar These cells have been implicated in the pathogenesis of a number of autoimmune diseases, including psoriasis and rheumatoid arthritis.3Molet S.M. Hamid Q.A. Hamilos D.L. IL-11 and IL-17 expression in nasal polyps: relationship to collagen deposition and suppression by intranasal fluticasone propionate.Laryngoscope. 2003; 113: 1803-1812Crossref PubMed Scopus (91) Google Scholar We have reported previously that IL-17A is upregulated in asthma and in nasal polyposis, and in the latter condition, its expression is resistant to topical steroids,4Ying S. Durham S.R. Corrigan C.J. Hamid Q. Kay A.B. Phenotype of cells expressing mRNA for TH2-type (interleukin 4 and interleukin 5) and TH1-type (interleukin 2 and interferon gamma) cytokines in bronchoalveolar lavage and bronchial biopsies from atopic asthmatic and normal control subjects.Am J Respir Cell Mol Biol. 1995; 12: 477-487Crossref PubMed Scopus (326) Google Scholar consistent with a recent report showing an association between a TH17-driven murine model of asthma and resistance to corticosteroids. A similar steroid hyporesponsiveness appears to be a feature of severe asthma. TH17 cells also produce TNF-α, which has been reported to be an important mediator of severe asthma and has itself been implicated in the induction of a number of proinflammatory cytokines. To induce TH17 cells, there is a requirement for IL-6 and TGF-β, and all of these cytokines have also been reported in association with severe asthma.5Veldhoen M. Hocking R.J. Atkins C.J. Locksley R.M. Stockinger B. TGFbeta in the context of an inflammatory cytokine milieu supports de novo differentiation of IL-17-producing T cells.Immunity. 2006; 24: 179-189Abstract Full Text Full Text PDF PubMed Scopus (3099) Google Scholar IL-23 is an important cytokine involved in the regulation of TH17 cells, but it is principally associated with the maintenance rather than induction of this phenotype.6Aggarwal S. Ghilardi N. Xie M.H. de Sauvage F.J. Gurney A.L. Interleukin-23 promotes a distinct CD4 T cell activation state characterized by the production of interleukin-17.J Biol Chem. 2003; 278: 1910-1914Crossref PubMed Scopus (1536) Google Scholar The TH17-derived cytokines are important in the induction and activation of neutrophils and could also be involved in promoting the proinflammatory properties of structural cells, exemplified by the secretion of IL-6 and IL-8 from airway epithelial cells. The objectives of our study were to investigate the expression of IL-17A and IL-17F in the airways of patients with asthma of varying severity. Airway tissues were obtained by bronchoscopy performed under light sedation following American Thoracic Society guidelines for biopsies of patients with severe asthma (n = 10), moderate asthma (n = 10), and mild asthma (n = 10), and controls without asthma. The diagnosis and severity of asthma were based on American Thoracic Society criteria. Subjects were recruited from the Montreal Chest Institute and Sacré Coeur Hospital. The protocols for the study were reviewed and approved by the Ethics Committees of both hospitals, and informed consent was obtained from all participating subjects. To detect the expression of IL-17A and IL-17F, immunocytochemistry was performed as previously described7Lindén A. Role of interleukin-17 and the neutrophil in asthma.Int Arch Allergy Immunol. 2001; 126: 179-184Crossref PubMed Scopus (125) Google Scholar using polyclonal goat antihuman IL-17F antibody (catalog no. AF1335, concentration 0.33 μg/mL [1:300]; R&D Systems, Minneapolis, MN) with antigen retrieval. Polyclonal IL-17A goat antihuman antibody (catalog no. AF-317-NA, concentration 0.83 μg/mL [1:120]; R&D Systems) was used to detect IL-17A immunoreactivity. The number of immunoreactive cells infiltrating the mucosa was assessed and expressed per square millimeter of tissue. Epithelial expression of IL-17F was assessed by using a scoring technique based on the percentage of positive epithelium. To confirm the results, real-time PCR was performed by using a LightCycler PCR machine with SyberGreen reagents (Roche, Mannheim, Germany) on RNA samples extracted from tissues from 5 cases per group with specific primers for IL-17A and IL-17F. IL-17A was expressed in all groups, and it was almost exclusively expressed in mononuclear cells present in the subepithelial tissue within clusters of inflammatory cells (Fig 1). Some immunoreactive cells were present in the epithelium and within smooth muscle bundles. The number of IL-17A+ cells was significantly higher in the patients with severe asthma compared with all other groups. There was also an increase in these cells in subject with moderate but not in mild asthma compared with controls. In contrast, IL-17F was expressed in both epithelial cells and inflammatory infiltrates (Fig 2). IL-17F+ cells in the subepithelial compartment were significantly elevated only in the subjects with severe asthma, whereas the epithelial expression was also elevated in moderate subjects compared with controls. To confirm the ability of the epithelium to produce IL-17F, we performed laser capture on 3 different biopsies and extracted RNA for PCR analysis, in which all samples showed a positive signal. Results from real-time quantitative PCR performed on airway biopsies confirmed an increase in mRNA for both IL-17A and IL-17F in the severe asthma groups (Fig 3). We found an increase in expression in TGF-β, TNF-α, and IL-6 (unpublished data) in a similar group of subjects with severe asthma.Fig 2Evidence for IL-17F immunoreactivity in airway epithelium from subjects with asthma. Representative immunocytochemistry staining for IL-17F in bronchial epithelium from a normal control (A) and a patient with severe asthma (B). C, The intensity of IL-17F immunoreactivity was graded by blind scorers and expressed as scores of stained epithelium (0 = no staining; 8 = 100% staining). ∗P < .05.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 3IL-17A and IL-17F cytokine mRNA expression in bronchial biopsies from normal controls and patients with mild, moderate, and severe asthma, relative to glyceraldehyde-3-phosphate dehydrogenase (GAPDH), as determined by quantitative real-time PCR (n = 5 per group). ∗P < .05.View Large Image Figure ViewerDownload Hi-res image Download (PPT) This is the first report of the expression of TH17-related cytokines in the airway tissues in severe asthma. Although we did not perform colocalization studies, the pattern of the immunoreactive cells in the submucosa suggests that this new subset of T cells may be involved in the inflammatory process in severe asthma. IL-17 has been associated with the activation of epithelial cells in vitro and the induction of IL-6 and IL-8 with downstream effects on neutrophil recruitment and activation.7Lindén A. Role of interleukin-17 and the neutrophil in asthma.Int Arch Allergy Immunol. 2001; 126: 179-184Crossref PubMed Scopus (125) Google Scholar We and others have reported an upregulation of IL-8 in severe asthma.8Shannon J. Ernst P. Yamauchi Y. Olivenstein R. Lemiere C. Foley S. et al.Differences in airway cytokine profile in severe asthma compared to moderate asthma.Chest. 2008; 133: 420-426Crossref PubMed Scopus (189) Google Scholar Neutrophils were also shown to be increased in severe asthma by many groups,9Turato G. Baraldo S. Zuin R. Saetta M. The laws of attraction: chemokines, neutrophils and eosinophils in severe exacerbations of asthma.Thorax. 2007; 62: 465-466Crossref PubMed Scopus (14) Google Scholar and this phenomenon may be IL-17–driven. We have also previously reported that IL-17 is increased in chronic sinusitis and that its expression is resistant to steroids.4Ying S. Durham S.R. Corrigan C.J. Hamid Q. Kay A.B. Phenotype of cells expressing mRNA for TH2-type (interleukin 4 and interleukin 5) and TH1-type (interleukin 2 and interferon gamma) cytokines in bronchoalveolar lavage and bronchial biopsies from atopic asthmatic and normal control subjects.Am J Respir Cell Mol Biol. 1995; 12: 477-487Crossref PubMed Scopus (326) Google Scholar Steroid unresponsiveness in severe asthma has been attributed to the presence of neutrophilic inflammation and an upregulation of the glucocorticoid receptor β isoform. TH17-related cytokines have been implicated in the pathogenesis of a number of diseases that do not respond well to corticosteroids. Recently McKinley et al10McKinley L. Alcorn J.F. Peterson A. Dupont R.B. Kapadia S. Logar A. et al.TH17 cells mediate steroid-resistant airway inflammation and airway hyperresponsiveness in mice.J Immunol. 2008; 181: 4089-4097PubMed Google Scholar have shown in a murine model that TH17 cells not only are proinflammatory cells but also may induce steroid resistance. It is possible that steroid hyporesponsiveness in subjects with severe asthma may also relate to the presence of IL-17A and IL-17F. IL-17 has also been reported to affect structural cells and to stimulate the production of profibrotic cytokines and extracellular matrix proteins. This feature of airway remodeling in severe asthma may be attributable to an excess of these cytokines. If so, targeting IL-17 cytokines may be of value in the therapy of severe asthma, in which steroid resistance, neutrophilic inflammation, and airway remodeling are substantial.

Background: ADAM33, a disintegrin and metalloproteinase 33 gene, has been identified as a risk factor for asthma and bronchial hyperresponsiveness and has been postulated as a gene for airway remodeling. ADAM8 is strongly induced by allergens and T(H)2 cytokines; in the lung in experimental asthma.Objectives: To assess the importance of these genes in asthma pathogenesis and to investigate whether expression relates to disease severity or deterioration in lung function, we measured the mRNA and protein expression of both genes in bronchial biopsies of subjects with asthma and control subjects.Methods: RNA was extracted from frozen endobronchial biopsies of mild. moderate, and severe adults with asthma and controls. Subjects with moderate and severe asthma were taking corticosteroids. The mRNA transcript of both genes was measured by real time RT-PCR using specific primers. Protein expression was examined by immunohistochemistry on paraffin sections.Results: ADAM33 mRNA expression was significantly higher in both moderate and severe asthma compared with mild asthma (P <.05) and controls. Immunostaining for ADAM33 was increased in the epithelium, submucosal cells, and smooth muscle in severe asthma compared with mild disease and controls. ADAM8 mRNA expression was significantly increased in all asthma groups compared with controls. Increased inflammatory cells stained positive for ADAM8 in both moderate (P <.05) and severe asthma (P <.005) compared with mild disease.Conclusions: These results demonstrate increased expression of both ADAM genes as asthma severity increases. Clinical implications: These genes may contribute to the remodeling process that occurs with asthma progression and may have implications for future treatment in severe disease.