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Severe asthma impacts quality of life (QoL), including dyspnea, sleep, and activity limitation. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukins-4/-13, key and central drivers of type 2 inflammation. Phase 3 VENTURE (NCT02528214) and TRAVERSE open-label extension (NCT02134028) evaluated dupilumab 300 mg vs placebo every 2 weeks for 24 weeks (VENTURE) and dupilumab only for an additional 48-96 weeks (TRAVERSE) in patients with oral corticosteroid (OCS)-dependent severe asthma.To assess dupilumab's impact on Asthma Quality of Life Questionnaire (AQLQ) items related to breathing symptoms, sleep, and activity limitation, and on OCS reduction.Proportion of patients with AQLQ scores of 6/7 for breathing symptoms-, sleeping-, and activity-related items in VENTURE and TRAVERSE, together with OCS dose reductions in VENTURE.In VENTURE, significantly greater proportions of dupilumab- vs placebo-treated patients achieved scores of 6/7 by week 24 in breathing symptoms- (42.7-60.2% vs 22.4-39.3%), sleeping- (45.6-65.0% vs 27.1-47.7%), and activity-related (44.7-51.5% vs 22.4-34.6%) AQLQ items. Improvements were maintained through TRAVERSE in the dupilumab/dupilumab group and increased to dupilumab treatment levels in the placebo/dupilumab group. Significant OCS dose reductions were observed in VENTURE; up to 90% and 60% of dupilumab- vs 65% and 41% of placebo-treated patients with AQLQ scores of 6/7 in breathing symptoms-, sleeping-, and activity-related items achieved ≥50% dose reduction and eliminated OCS at week 24, respectively.In patients with severe OCS-dependent asthma, dupilumab improved QoL related to breathing symptoms, sleep, and activity limitation, and reduced OCS use.

The severe acute respiratory syndrome coronavirus 2 pandemic poses extraordinary challenges. The tremendous number of coronavirus disease 2019 (COVID-19) cases in the United States has resulted in a large population of survivors with prolonged postinfection symptoms. The creation of multidisciplinary post-COVID-19 clinics to address both persistent symptoms and potential long-term complications requires an understanding of the acute disease and the emerging data regarding COVID-19 outcomes. Experience with severe acute respiratory syndrome and Middle East respiratory syndrome, post-acute respiratory distress syndrome complications, and post-intensive care syndrome also informs anticipated sequelae and clinical program design. Post-COVID-19 clinical programs should be prepared to care for individuals previously hospitalized with COVID-19 (including those who required critical care support), nonhospitalized individuals with persistent respiratory symptoms following COVID-19, and individuals with preexisting lung disease complicated by COVID-19. Effective multidisciplinary collaboration models leverage lessons learned during the early phases of the pandemic to overcome the unique logistical challenges posed by pandemic circumstances. Collaboration between physicians and researchers across disciplines will provide insight into survivorship that may shape the treatment of both acute disease and chronic complications. In this review, we discuss the aims, general principles, elements of design, and challenges of a successful multidisciplinary model to address the needs of COVID-19 survivors.

RationaleAsthma is a chronic airway disease driven by multiple immunologic pathways that determine the clinical response to therapy. Current diagnostic methods are incapable of discriminating subtypes of asthma and guiding targeted treatment. We hypothesized that sputum cytokine profiles could help to identify immunologically-defined disease subtypes and individualize therapy in patients with severe asthma.ObjectivesDefine asthma subtypes associated with sputum alarmin and cytokine levels.MethodsCross-sectional analysis of clinical features and sputum from 200 asthmatic patients was performed. 10 cytokines belonging to alarmin, T2, and non-T2 pathways were measured. Pearson correlation was used to identify cytokine modules. Latent class analysis was used to cluster patients by cytokine expression.Measurements and Main ResultsThree modules of highly correlated cytokines were identified including a non-T2 module, the IL-1βmod (IL-1β, IL-6, GCSF), and two distinct T2 modules: TSLPmod (TSLP, IL-4, IL-5, IL-9) and IL-33mod (IL-33, IL-13, IL-21). The TSLPmod was associated with asthma severity, airway obstruction, eosinophilia, and elevated FeNO. Patient clustering revealed three subgroups; two different subgroups showed expression of T2 modules.ConclusionsAnalysis of sputum cytokines revealed three discrete signaling modules in patients with asthma. Unexpectedly, the inclusion of alarmins led to separation of canonical T2 cytokines into two unique modules; IL-5 grouped with TSLP, while IL-13 grouped with IL-33. In addition, patient clustering revealed two distinct endotypes associated with T2 immune signaling. These findings indicate a new layer of immunologic heterogeneity within the T2 paradigm, and suggest that sputum cytokine profiling may hold diagnostic utility for patients with asthma.

Rationale: MicroRNAs are potent regulators of biologic systems that are critical to tissue homeostasis. Individual microRNAs have been identified in airway samples. However, a systems analysis of the microRNA–mRNA networks present in the sputum that contribute to airway inflammation in asthma has not been published. Objectives: Identify microRNA and mRNA networks in the sputum of patients with asthma. Methods: We conducted a genome-wide analysis of microRNA and mRNA in the sputum from patients with asthma and correlated expression with clinical phenotypes. Weighted gene correlation network analysis was implemented to identify microRNA networks (modules) that significantly correlate with clinical features of asthma and mRNA expression networks. MicroRNA expression in peripheral blood neutrophils and lymphocytes and in situ hybridization of the sputum were used to identify the cellular sources of microRNAs. MicroRNA expression obtained before and after ozone exposure was also used to identify changes associated with neutrophil counts in the airway. Measurements and Main Results: Six microRNA modules were associated with clinical features of asthma. A single module (nely) was associated with a history of hospitalizations, lung function impairment, and numbers of neutrophils and lymphocytes in the sputum. Of the 12 microRNAs in the nely module, hsa-miR-223-3p was the highest expressed microRNA in neutrophils and was associated with increased neutrophil counts in the sputum in response to ozone exposure. Multiple microRNAs in the nely module correlated with two mRNA modules enriched for TLR (Toll-like receptor) and T-helper cell type 17 (Th17) signaling and endoplasmic reticulum stress. hsa-miR-223-3p was a key regulator of the TLR and Th17 pathways in the sputum of subjects with asthma. Conclusions: This study of sputum microRNA and mRNA expression from patients with asthma demonstrates the existence of microRNA networks and genes that are associated with features of asthma severity. Among these, hsa-miR-223-3p, a neutrophil-derived microRNA, regulates TLR/Th17 signaling and endoplasmic reticulum stress.

Min Yang,1 Jingdong Chao,2 Mirko Fillbrunn,1 Usha G Mallya,3 Min-Jung Wang,1 Leigh Franke,1 Lauren Cohn,4,5 Siddhesh Kamat2 1Analysis Group, Inc, Boston, MA, USA; 2Regeneron Pharmaceuticals, Inc, Tarrytown, NY, USA; 3Sanofi, Boston, MA, USA; 4Section of Pulmonary, Critical Care and Sleep Medicine, Yale School of Medicine, New Haven, CT, USA; 5VA Connecticut Healthcare System, West Haven, CT, USACorrespondence: Min Yang, Analysis Group, Inc, 111 Huntington Avenue, Fourteenth Floor, Boston, MA, 02199, USA, Tel +1-617-425-8487, Fax +1-617-425-8001, Email Min.Yang@analysisgroup.comPurpose: Multiple biologics are available for moderate to severe asthma. Given the important relationship between patient engagement in healthcare decision-making and health outcomes, patient preference is an increasingly important consideration. This study elicited patients’ preferences for attributes of biologic therapies for moderate to severe asthma.Patient and Methods: A discrete choice experiment (DCE) questionnaire was designed to collect data from an existing survey panel of adults with moderate to severe asthma in the United States. Patients were asked to select their preferred hypothetical treatment from profiles with varying attributes related to efficacy, safety, and administration convenience. Conditional logit regression models were used to quantify patient preferences.Results: Of 301 eligible patients who completed the survey, the mean age was 46.7± 15.1 years and 71.8% were female. Patients had asthma for 22.5± 16.3 years on average, and most (97.3%) had experienced ≥ 1 asthma attack in the past 12 months. Among treatment attributes examined, patients most valued the absence of a black box warning for the risk of a life-threatening allergic reaction, effectiveness of reducing severe asthma exacerbations, and improvement in lung function (all p < 0.001). Home administration setting for subcutaneous injections (vs doctor’s office/clinic) (p = 0.009) and ability of a biologic to treat additional chronic condition(s) (p < 0.05) were also considered important. Dosing frequency and type of injection device were not significant factors.Conclusion: Patients with moderate to severe asthma valued efficacy and safety over convenience attributes when selecting biologic treatments. Awareness of these preferences can facilitate patient-physician shared decision-making when managing moderate to severe asthma in clinical practice.Keywords: asthma, patient preference, biologic, treatment

Asthma is a heterogeneous disease, with multiple underlying inflammatory pathways and structural airway abnormalities that impact disease persistence and severity. Recent progress has been made in developing targeted asthma therapeutics, especially for subjects with eosinophilic asthma. However, there is an unmet need for new approaches to treat patients with severe and exacerbation-prone asthma, who contribute disproportionately to disease burden. Extensive deep phenotyping has revealed the heterogeneous nature of severe asthma and identified distinct disease subtypes. Acurrent challenge in the field is to translate new and emerging knowledge about different pathobiologic mechanisms in asthma into patient-specific therapies, with the ultimate goal of modifying the natural history of disease. Here, we describe the Precision Interventions for Severe and/or Exacerbation-Prone Asthma (PrecISE) Network, a groundbreaking collaborative effort of asthma researchers and biostatisticians from around the United States. The PrecISE Network was designed to conduct phase II/proof-of-concept clinical trials of precision interventions in the population with severe asthma, and is supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Using an innovative adaptive platform trial design, the PrecISE Network will evaluate up to 6 interventions simultaneously in biomarker-defined subgroups of subjects. We review the development and organizational structure of the PrecISE Network, and choice of interventions being studied. We hope that the PrecISE Network will enhance our understanding of asthma subtypes and accelerate the development of therapeutics for severe asthma.

Background: The Asthma Quality of Life Questionnaire (AQLQ) includes items assessing the impact of asthma on sleep in patients (pts). Dupilumab (DPL), a fully human mAb, blocks the shared receptor component for IL-4/IL-13, key and central drivers of type 2 inflammation in multiple diseases. In phase 3 VENTURE (NCT02528214), DPL 300mg every 2 weeks (q2w) vs placebo (PBO) reduced oral corticosteroid (OCS) maintenance dose and rate of severe asthma exacerbations and improved pre-bronchodilator FEV1 and health-related quality of life in pts with OCS-dependent, severe asthma. DPL was generally well tolerated. Aim: To assess the effect of DPL on pt-reported sleep outcomes in VENTURE. Methods: Four AQLQ items assess the impact of asthma on sleep on a scale of 1–7; scores of 6/7 indicate little/no impact of asthma. The proportion of pts with scores of 6/7 on the sleep-related items (#5, #20, #24, and #29) was evaluated at baseline (BL), Week (Wk) 12 and 24. Results: The proportion of pts reporting little/no impact of asthma on sleep-related items at BL was 17%–37%, suggesting that most pts experienced sleep impairment. A greater proportion of DPL pts vs PBO reported little/no impact of asthma on sleep at Wk 24 (P Conclusion: Pts with OCS-dependent, severe asthma had impaired sleep at BL. At Wk 24, a greater proportion of DPL pts reported waking up with asthma symptoms hardly any or none of the time vs PBO.

Bpifa1 (BPI fold-containing group A member 1) is an airway host-protective protein with immunomodulatory properties that binds to LPS and is regulated by infectious and inflammatory signals. Differential expression of Bpifa1 has been widely reported in lung disease, yet the biological significance of this observation is unclear. We sought to understand the role of Bpifa1 fluctuations in modulating lung inflammation. We treated wild-type (WT) and Bpifa1−/− mice with intranasal LPS and performed immunological and transcriptomic analyses of lung tissue to determine the immune effects of Bpifa1 deficiency. We show that neutrophil (polymorphonuclear cells, PMNs) lung recruitment and transmigration to the airways in response to LPS is impaired in Bpifa1−/− mice. Transcriptomic analysis revealed a signature of 379 genes that differentiated Bpifa1−/− from WT mice. During acute lung inflammation, the most downregulated genes in Bpifa1−/− mice were Cxcl9 and Cxcl10. Bpifa1−/− mice had lower bronchoalveolar lavage concentrations of C-X-C motif chemokine ligand 10 (Cxcl10) and Cxcl9, interferon-inducible PMN chemokines. This was consistent with lower expression of IFNγ, IFNλ, downstream IFN-stimulated genes, and IFN-regulatory factors, which are important for the innate immune response. Administration of Cxcl10 before LPS treatment restored the inflammatory response in Bpifa1−/− mice. Our results identify a novel role for Bpifa1 in the regulation of Cxcl10-mediated PMN recruitment to the lungs via IFNγ and -λ signaling during acute inflammation.

Acute pulmonary Exacerbations (AE) are episodes of clinical worsening in cystic fibrosis (CF), often precipitated by infection. Timely detection is critical to minimize the morbidity and lung function decline associated with acute inflammation during AE. We previously demonstrated that the airway protein Short Palate Lung Nasal epithelium Clone 1 (SPLUNC1) is regulated by inflammatory signals. Here, we investigated the use of SPLUNC1 fluctuations to diagnose and predict AE in CF. We enrolled adult CF subjects from two independent cohorts to measure AE markers of inflammation in sputum and recorded clinical outcomes for a 1-year follow-up period. SPLUNC1 levels were high in healthy control sputum (n=9, 10.7μg/mL), and significantly decreased in CF subjects without AE (n=30, 5.7μg/mL, p=0.016). SPLUNC1 levels were 71.9% lower during AE (n=14, 1.6μg/mL, p=0.0034) regardless of age, sex, CF-causing mutation, or microbiology findings. Cytokines Il–1β and TNFα were also increased in AE,whereas lung function did not consistently decrease. Stable CF subjects with lower SPLUNC1 levels were much more likely to have an AE at 60 days (Hazard Ratio: 11.49, Standard Error: 0.83, p=0.0033). Low-SPLUNC1 stable subjects remained at higher AE risk even one year after sputum collection (Hazard Ratio: 3.21, Standard Error: 0.47,p=0.0125). SPLUNC1 was transcriptionally downregulated by inflammatory cytokines and degraded by proteases increased in sputum during AE. Our findings suggest that low sputum SPLUNC1 levels could detect subjects at increased risk of AE in order to guide early therapeutic interventions in CF. TAKE-HOME MESSAGE Sputum concentrations of the secreted airway protein SPLUNC1 decrease during CF exacerbations. Lower SPLUNC1 levels in stable subjects portend a significantly increased risk of exacerbation and could inform therapeutic interventions. PLAIN LANGUAGE SUMMARY SPLUNC1 is an abundant host defense protein found in the respiratory tract that decreases with inflammation. Individuals with cystic fibrosis experiencing clinical worsening (exacerbation) have much lower levels of SPLUNC1 in their sputum. In stable cystic fibrosis patients, lower levels of SPLUNC1 may predict an upcoming respiratory illness. Therefore, SPLUNC1 may serve as a tool for early diagnosis and treatment of cystic fibrosis exacerbations.

Surfactant protein C (SPC), a key component of pulmonary surfactant, also plays a role in regulating inflammation. SPC deficiency in patients and mouse models is associated with increased inflammation and delayed repair, but the key drivers of SPC-regulated inflammation in response to injury are largely unknown. This study focuses on a new mechanism of SPC as an anti-inflammatory molecule using SPC-TK/SPC-KO (surfactant protein C-thymidine kinase/surfactant protein C knockout) mice, which represent a novel sterile injury model that mimics clinical acute respiratory distress syndrome (ARDS). SPC-TK mice express the inducible suicide gene thymidine kinase from by the SPC promoter, which targets alveolar type 2 (AT2) cells for depletion in response to ganciclovir (GCV). We compared GCV-induced injury and repair in SPC-TK mice that have normal endogenous SPC expression with SPC-TK/SPC-KO mice lacking SPC expression. In contrast to SPC-TK mice, SPC-TK/SPC-KO mice treated with GCV exhibited more severe inflammation, resulting in over 90% mortality; there was only 8% mortality of SPC-TK animals. SPC-TK/SPC-KO mice had highly elevated inflammatory cytokines and granulocyte infiltration in the bronchoalveolar lavage (BAL) fluid. Consistent with a proinflammatory phenotype, immunofluorescence revealed increased phosphorylated signal transduction and activation of transcription 3 (pSTAT3), suggesting enhanced Janus kinase (JAK)/STAT activation in inflammatory and AT2 cells of SPC-TK/SPC-KO mice. The level of suppressor of cytokine signaling 3, an anti-inflammatory mediator that decreases pSTAT3 signaling, was significantly decreased in the BAL fluid of SPC-TK/SPC-KO mice. Hyperactivation of pSTAT3 and inflammation were rescued by AZD1480, a JAK1/2 inhibitor. Our findings showing a novel role for SPC in regulating inflammation via JAK/STAT may have clinical applications.

Background Airway eosinophilia is a prominent feature of asthma and chronic rhinosinusitis (CRS), and the endothelium plays a key role in eosinophil trafficking. To date, microRNA-1 (miR-1) is the only microRNA known to be regulated in the lung endothelium in asthma models. Objective We sought to determine the role of endothelial miR-1 in allergic airway inflammation. Methods We measured microRNA and mRNA expression using quantitative RT-PCR. We used ovalbumin and house dust mite models of asthma. Endothelium-specific overexpression of miR-1 was achieved through lentiviral vector delivery or induction of a transgene. Tissue eosinophilia was quantified by using Congo red and anti-eosinophil peroxidase staining. We measured eosinophil binding with a Sykes-Moore adhesion chamber. Target recruitment to RNA-induced silencing complex was assessed by using anti-Argonaute2 RNA immunoprecipitation. Surface P-selectin levels were measured by using flow cytometry. Results Serum miR-1 levels had inverse correlations with sputum eosinophilia, airway obstruction, and number of hospitalizations in asthmatic patients and sinonasal tissue eosinophilia in patients with CRS. IL-13 stimulation decreased miR-1 levels in human lung endothelium. Endothelium-specific overexpression of miR-1 reduced airway eosinophilia and asthma phenotypes in murine models and inhibited IL-13–induced eosinophil binding to endothelial cells. miR-1 recruited P-selectin, thymic stromal lymphopoietin, eotaxin-3, and thrombopoietin receptor to the RNA-induced silencing complex; downregulated these genes in the lung endothelium; and reduced surface P-selectin levels in IL-13–stimulated endothelial cells. In our asthma and CRS cohorts, miR-1 levels correlated inversely with its target genes. Conclusion Endothelial miR-1 regulates eosinophil trafficking in the setting of allergic airway inflammation. miR-1 has therapeutic potential in asthmatic patients and patients with CRS.

BackgroundAcute pulmonary exacerbations (AE) are episodes of clinical worsening in cystic fibrosis (CF), often precipitated by infection. Timely detection is critical to minimise morbidity and lung function declines associated with acute inflammation during AE. Based on our previous observations that airway protein short palate lung nasal epithelium clone 1 (SPLUNC1) is regulated by inflammatory signals, we investigated the use of SPLUNC1 fluctuations to diagnose and predict AE in CF.MethodsWe enrolled CF participants from two independent cohorts to measure AE markers of inflammation in sputum and recorded clinical outcomes for a 1-year follow-up period.ResultsSPLUNC1 levels were high in healthy controls (n=9, 10.7 μg·mL–1), and significantly decreased in CF participants without AE (n=30, 5.7 μg·mL–1; p=0.016). SPLUNC1 levels were 71.9% lower during AE (n=14, 1.6 μg·mL–1; p=0.0034) regardless of age, sex, CF-causing mutation or microbiology findings. Cytokines interleukin-1β and tumour necrosis factor-α were also increased in AE, whereas lung function did not decrease consistently. Stable CF participants with lower SPLUNC1 levels were much more likely to have an AE at 60 days (hazard ratio (HR)±se11.49±0.83; p=0.0033). Low-SPLUNC1 stable participants remained at higher AE risk even 1 year after sputum collection (HR±se3.21±0.47; p=0.0125). SPLUNC1 was downregulated by inflammatory cytokines and proteases increased in sputum during AE.ConclusionIn acute CF care, low SPLUNC1 levels could support a decision to increase airway clearance or to initiate pharmacological interventions. In asymptomatic, stable patients, low SPLUNC1 levels could inform changes in clinical management to improve long-term disease control and clinical outcomes in CF.

Mucin-secreting goblet cell metaplasia and hyperplasia (GCMH) is a common pathological phenotype in many human respiratory diseases, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, primary ciliary dyskinesia, and infections. A better understanding of how goblet cell quantities or proportions in the airway epithelium are regulated may provide novel therapeutic targets to mitigate GCMH in these devastating diseases. We identify canonical SMAD signaling as the principal pathway restricting goblet cell differentiation in human airway epithelium. Differentiated goblet cells express low levels of phosphorylated SMAD. Accordingly, inhibition of SMAD signaling markedly amplifies GCMH induced by mucous mediators. In contrast, SMAD signaling activation impedes goblet cell generation and accelerates the resolution of preexisting GCMH. SMAD signaling inhibition can override the suppressive effects imposed by a GABAergic receptor inhibitor, suggesting the GABAergic pathway likely operates through inhibition of SMAD signaling in regulating mucous differentiation. Collectively, our data demonstrate that SMAD signaling plays a determining role in mucous cell differentiation, and thus raise the possibility that dysregulation of this pathway contributes to respiratory pathophysiology during airway inflammation and pulmonary diseases. In addition, our study also highlights the potential for SMAD modulation as a therapeutic target in mitigating GCMH.

Bactericidal/permeability-increasing protein fold–containing family member A1 (BPIFA1), formerly known as SPLUNC1, is one of the most abundant proteins in respiratory secretions and has been identified with increasing frequency in studies of pulmonary disease. Its expression is largely restricted to the respiratory tract, being highly concentrated in the upper airways and proximal trachea. BPIFA1 is highly responsive to airborne pathogens, allergens, and irritants. BPIFA1 actively participates in host protection through antimicrobial, surfactant, airway surface liquid regulation, and immunomodulatory properties. Its expression is modulated in multiple lung diseases, including cystic fibrosis, chronic obstructive pulmonary disease, respiratory malignancies, and idiopathic pulmonary fibrosis. However, the role of BPIFA1 in pulmonary pathogenesis remains to be elucidated. This review highlights the versatile properties of BPIFA1 in antimicrobial protection and its roles as a sensor of environmental exposure and regulator of immune cell function. A greater understanding of the contribution of BPIFA1 to disease pathogenesis and activity may clarify if BPIFA1 is a biomarker and potential drug target in pulmonary disease.

Bronchial thermoplasty is an endoscopic therapy for severe asthma. The previously reported, randomised sham-controlled AIR2 (Asthma Intervention Research 2) trial showed a significant reduction in severe asthma exacerbations, emergency department visits and hospitalisations after bronchial thermoplasty. More “real-world” clinical outcome data is needed. This article compares outcomes in bronchial thermoplasty subjects with 3 years of follow-up from the ongoing, post-market PAS2 (Post-FDA Approval Clinical Trial Evaluating Bronchial Thermoplasty in Severe Persistent Asthma) study with those from the AIR2 trial. 279 subjects were treated with bronchial thermoplasty in the PAS2 study. We compared the first 190 PAS2 subjects with the 190 bronchial thermoplasty-treated subjects in the AIR2 trial at 3 years of follow-up. The PAS2 subjects were older (mean age 45.9 versus 40.7 years) and more obese (mean body mass index 32.5 versus 29.3 kg·m−2) and took higher doses of inhaled corticosteroids (mean dose 2301 versus 1961 μg·day−1). More PAS2 subjects had experienced severe exacerbations (74% versus 52%) and hospitalisations (15.3% versus 4.2%) in the 12 months prior to bronchial thermoplasty. At year 3 after bronchial thermoplasty, the percentage of PAS2 subjects with severe exacerbations, emergency department visits and hospitalisations significantly decreased by 45%, 55% and 40%, respectively, echoing the AIR2 results. The PAS2 study demonstrates similar improvements in asthma control after bronchial thermoplasty compared with the AIR2 trial despite enrolling subjects who may have had poorer asthma control., A comparison of the results obtained thus far in PAS2 with AIR2 evaluating bronchial thermoplasty in severe asthma http://ow.ly/sB0X30csDuE

Bronchial thermoplasty is an endoscopic therapy for severe asthma. The previously reported, randomised sham-controlled AIR2 (Asthma Intervention Research 2) trial showed a significant reduction in severe asthma exacerbations, emergency department visits and hospitalisations after bronchial thermoplasty. More “real-world” clinical outcome data is needed. This article compares outcomes in bronchial thermoplasty subjects with 3 years of follow-up from the ongoing, post-market PAS2 (Post-FDA Approval Clinical Trial Evaluating Bronchial Thermoplasty in Severe Persistent Asthma) study with those from the AIR2 trial. 279 subjects were treated with bronchial thermoplasty in the PAS2 study. We compared the first 190 PAS2 subjects with the 190 bronchial thermoplasty-treated subjects in the AIR2 trial at 3 years of follow-up. The PAS2 subjects were older (mean age 45.9 versus 40.7 years) and more obese (mean body mass index 32.5 versus 29.3 kg·m −2 ) and took higher doses of inhaled corticosteroids (mean dose 2301 versus 1961 μg·day −1 ). More PAS2 subjects had experienced severe exacerbations (74% versus 52%) and hospitalisations (15.3% versus 4.2%) in the 12 months prior to bronchial thermoplasty. At year 3 after bronchial thermoplasty, the percentage of PAS2 subjects with severe exacerbations, emergency department visits and hospitalisations significantly decreased by 45%, 55% and 40%, respectively, echoing the AIR2 results. The PAS2 study demonstrates similar improvements in asthma control after bronchial thermoplasty compared with the AIR2 trial despite enrolling subjects who may have had poorer asthma control.

Introduction: The p38 Mitogen-Activated Protein Kinase pathway is dysregulated in asthma. MK2 is a p38 terminal kinase that regulates multiple asthma relevant genes(e.g. ALOX5, TNF-a, IL-6, dendritic cell Toll-like receptors), but its role in human asthma is unknown. We hypothesized MK2 expression is increased in asthma. Methods: Whole transcriptome gene expression profiles in sputum and blood were measured(Affymetrix ST 1.0) from 112 asthmatics and 12 controls. MK2 gene expression was correlated with clinical, physiologic and inflammatory disease characteristics. Results: Sputum MK2 gene expression was increased in asthmatics vs. controls(p=0.04) and correlated positively with lifetime hospitalizations(p=0.03) and Severe Asthma Research Program(SARP) cluster designation, and negatively with serum IgE levels(r=-0.28,p Conclusions: Sputum MK2 gene expression is significantly elevated in asthma, associated with poor lung function, neutrophilic inflammation and increased sputum chitinase activity. These data suggest MK2 mediates airway inflammation in asthma, particularly in severe phenotypes of disease, and warrants investigation as a therapeutic target.

BACKGROUND : Analysis of inflammatory cell populations in induced sputum has been used to identify subgroups of asthma, but the associated cytokine/chemokine profiles of these subgroups have not been defined. METHODS : Questionnaires, blood collection, spirometry, and sputum induction were completed by 299 asthmatics. Subgroups were determined using the method defined by Simpson et al (Respirology 2006). Sputum eosinophil and neutrophil cutoffs were 5.4% and 45.4%, respectively. Cytokine levels in mucus supernatants were measured by Luminex and analyzed using non-parametric tests. RESULTS : The paucigranulocytic subgroup was the largest followed by the eosinophilic, neutrophilic, and mixed. The neutrophilic, eosinophilic, and mixed subgroups had more moderate and severe asthmatics with equal risks of severe and near fatal exacerbations. The neutrophilic subgroup had the youngest median age of disease onset and lowest FENO overall, and higher levels of IL-8 (2746 vs. 654, pg/mL, p=0.002) and IP-10 (8448 vs. 2390, pg/mL, p=0.008) compared to the eosinophilic subgroup. A trend was seen for higher IL-6 levels in the neutrophilic subgroup compared to the other subgroups. CONCLUSIONS : The neutrophilic, eosinophilic, and mixed subgroups displayed nearly identical sputum cytokine/chemokine profiles. The distinguishing characteristics of the neutrophilic subgroup were the higher levels of proinflammatory cytokines IL-8, IL-6 and the antimicrobial protein IP-10. IP-10 has been associated with refractory upper airway inflammation and rhinovirus-induced asthma exacerbations. This suggests the neutrophilic subgroup may be more susceptible to viral-mediated asthma exacerbations.

The reticulon protein Nogo-B is highly expressed in the lungs, and its loss augments lung inflammation in part as a result of decreased expression of the antiinflammatory protein PLUNC., Nogo-B is a member of the reticulon family of proteins (RTN-4B) that is highly expressed in lung tissue; however, its function remains unknown. We show that mice with Th2-driven lung inflammation results in a loss of Nogo expression in airway epithelium and smooth muscle compared with nonallergic mice, a finding which is replicated in severe human asthma. Mice lacking Nogo-A/B (Nogo-KO) display an exaggerated asthma-like phenotype, and epithelial reconstitution of Nogo-B in transgenic mice blunts Th2-mediated lung inflammation. Microarray analysis of lungs from Nogo-KO mice reveals a marked reduction in palate lung and nasal clone (PLUNC) gene expression, and the levels of PLUNC are enhanced in epithelial Nogo-B transgenic mice. Finally, transgenic expression of PLUNC into Nogo-KO mice rescues the enhanced asthmatic-like responsiveness in these KO mice. These data identify Nogo-B as a novel protective gene expressed in lung epithelia, and its expression regulates the levels of the antibacterial antiinflammatory protein PLUNC.

Mucous cell metaplasia is induced in response to harmful insults and provides front-line protection to clear the airway of toxic substances and cellular debris. In chronic airway diseases mucous metaplasia persists and results in airway obstruction and contributes significantly to morbidity and mortality. Mucus hypersecretion involves increased expression of mucin genes, and increased mucin production and release. The past decade has seen significant advances in our understanding of the molecular mechanisms by which these events occur. Inflammation stimulates epidermal growth factor receptor activation and IL-13 to induce both Clara and ciliated cells to transition into goblet cells through the coordinated actions of FoxA2, TTF-1, SPDEF, and GABA(A)R. Ultimately, these steps lead to up-regulation of MUC5AC expression, and increased mucin in goblet cell granules that fuse to the plasma membrane through actions of MARCKS, SNAREs, and Munc proteins. Blockade of mucus in exacerbations of asthma and chronic obstructive pulmonary disease may affect morbidity. Development of new therapies to target mucus production and secretion are now possible given the advances in our understanding of molecular mechanisms of mucous metaplasia. We now have a greater incentive to focus on inhibition of mucus as a therapy for chronic airway diseases.

We previously demonstrated that vascular endothelial growth factor (VEGF) expression in the murine lung increases local CD11c+MHCII+ DC number and activation. In this study, employing a multicolor flow cytometry, we report increases in both myeloid (mDC) and plasmacytoid (pDC) DC in the lungs of VEGF transgenic (tg) compared to WT mice. Lung pDC from VEGF tg mice exhibited higher levels of activation with increased expression of MHCII and costimulatory molecules. As VEGF tg mice display an asthma-like phenotype and lung mDC play a critical role in asthmatic setting, studies were undertaken to further characterize murine lung mDC. Evaluations of sorted mDC from VEGF tg lungs demonstrated a selective upregulation of cathepsin K, MMP-8, -9, -12, and -14, and chemokine receptors as compared to those obtained from WT control mice. They also had increased VEGFR2 but downregulated VEGFR1 expression. Analysis of chemokine and regulatory cytokine expression in these cells showed an upregulation of macrophage chemotactic protein-3 (MCP-3), thymus-expressed chemokine (TECK), secondary lymphoid organ chemokine (SLC), macrophage-derived chemokine (MDC), IL-1beta, IL-6, IL-12 and IL-13. The antigen (Ag) OVA-FITC uptake by lung DC and the migration of Ag-loaded DC to local lymph nodes were significantly increased in VEGF tg mice compared to WT mice. Thus, VEGF may predispose the lung to inflammation and/or repair by activating local DC. It regulates lung mDC expression of innate immunity effector molecules. The data presented here demonstrate how lung VEGF expression functionally affects local mDC for the transition from the innate response to a Th2-type inflammatory response.

In allergic airway inflammation, dendritic cells (DCs) are required for Th2 generation, recruitment, and activation in the respiratory tract. DCs have been shown to be necessary and sufficient for the induction of Th1 immune responses. In Th2 immunity and allergic airway inflammation, the ability of a DC to function as the sole APC has not been tested. We show that CD11c/Aβb mice with MHC class II expression restricted to CD11c-expressing DCs develop airway neutrophilia rather than allergic airway inflammation. Although CD11c/Aβb mice are capable of Th2 recruitment and activation in the lung, Th2 priming in CD11c/Aβb mice results in IFN-γ production. Effective Th2 generation and allergic airway inflammation was achieved in CD11c/Aβb mice after treatment with anti-IFN-γ. These studies show that DCs alone cannot drive the development of Th2 cells but require an additional MHC class II signal to stimulate effective Th2 immunity.

Asthma is an inflammatory disorder caused by airway exposures to allergens and chemical irritants. Studies focusing on immune, smooth muscle, and airway epithelial function revealed many aspects of the disease mechanism of asthma. However, the limited efficacies of immune-directed therapies suggest the involvement of additional mechanisms in asthmatic airway inflammation. TRPA1 is an irritant-sensing ion channel expressed in airway chemosensory nerves. TRPA1-activating stimuli such as cigarette smoke, chlorine, aldehydes, and scents are among the most prevalent triggers of asthma. Endogenous TRPA1 agonists, including reactive oxygen species and lipid peroxidation products, are potent drivers of allergen-induced airway inflammation in asthma. Here, we examined the role of TRPA1 in allergic asthma in the murine ovalbumin model. Strikingly, genetic ablation of TRPA1 inhibited allergen-induced leukocyte infiltration in the airways, reduced cytokine and mucus production, and almost completely abolished airway hyperreactivity to contractile stimuli. This phenotype is recapitulated by treatment of wild-type mice with HC-030031, a TRPA1 antagonist. HC-030031, when administered during airway allergen challenge, inhibited eosinophil infiltration and prevented the development of airway hyperreactivity. Trpa1 −/− mice displayed deficiencies in chemically and allergen-induced neuropeptide release in the airways, providing a potential explanation for the impaired inflammatory response. Our data suggest that TRPA1 is a key integrator of interactions between the immune and nervous systems in the airways, driving asthmatic airway inflammation following inhaled allergen challenge. TRPA1 may represent a promising pharmacological target for the treatment of asthma and other allergic inflammatory conditions.

Mouse breast regression protein 39 (BRP-39; Chi3l1) and its human homologue YKL-40 are chitinase-like proteins that lack chitinase activity. Although YKL-40 is expressed in exaggerated quantities and correlates with disease activity in asthma and many other disorders, the biological properties of BRP-39/YKL-40 have only been rudimentarily defined. We describe the generation and characterization of BRP-39−/− mice, YKL-40 transgenic mice, and mice that lack BRP-39 and produce YKL-40 only in their pulmonary epithelium. Studies of these mice demonstrated that BRP-39−/− animals have markedly diminished antigen-induced Th2 responses and that epithelial YKL-40 rescues the Th2 responses in these animals. The ability of interleukin13 to induce tissue inflammation and fibrosis was also markedly diminished in the absence of BRP-39. Mechanistic investigations demonstrated that BRP-39 and YKL-40 play an essential role in antigen sensitization and immunoglobulin E induction, stimulate dendritic cell accumulation and activation, and induce alternative macrophage activation. These proteins also inhibit inflammatory cell apoptosis/cell death while inhibiting Fas expression, activating protein kinase B/AKT, and inducing Faim 3. These studies establish novel regulatory roles for BRP-39/YKL-40 in the initiation and effector phases of Th2 inflammation and remodeling and suggest that these proteins are therapeutic targets in Th2- and macrophage-mediated disorders.

IL-13 is a critical cytokine at sites of Th2 inflammation. In these locations it mediates its effects via a receptor complex, which contains IL-4Rα and IL-13Rα1. A third, high-affinity IL-13 receptor, IL-13Rα2, also exists. Although it was initially felt to be a decoy receptor, this has not been formally demonstrated and the role(s) of this receptor has recently become controversial. To define the role(s) of IL-13Rα2 in IL-13-induced pulmonary inflammation and remodeling, we compared the effects of lung-targeted transgenic IL-13 in mice with wild-type and null IL-13Rα2 loci. We also investigated the effect of IL-13Rα2 deficiency on the OVA-induced inflammatory response. In this study, we show that in the absence of IL-13Rα2, IL-13-induced pulmonary inflammation, mucus metaplasia, subepithelial fibrosis, and airway remodeling are significantly augmented. These changes were accompanied by increased expression and production of chemokines, proteases, mucin genes, and TGF-β1. Similarly, an enhanced inflammatory response was observed in an OVA-induced phenotype. In contrast, disruption of IL-13Rα2 had no effect on the tissue effects of lung-targeted transgenic IL-4. Thus, IL-13Rα2 is a selective and powerful inhibitor of IL-13-induced inflammatory, remodeling, and physiologic responses in the murine lung.

The STAT3 transcription factor is critical for cytokine signaling and the acute phase response, but its role in allergic asthma is largely undefined. To investigate the role of STAT3 in mediating allergic inflammation, we used chemical and genetic approaches to inactivate STAT3 in the airway epithelium of mice. In a murine model of chronic asthma, we demonstrate that the administration of house dust mite (HDM) leads to robust STAT3 activation in the airway epithelium, smooth muscle, and immune cells in the lungs of C57BL/6 mice. To investigate the role of STAT3 in HDM-induced airway inflammation, a conditional knockout of STAT3 in the airway epithelium was generated, e-STAT3−/−. We determined that e-STAT3−/− mice had a significant decrease in HDM-induced airway eosinophilia, lung Th2 accumulation, and chemokines compared with wild-type animals. Importantly, the e-STAT3−/− mice had a significant decrease in airway hyperresponsiveness to methacholine. The administration of two STAT kinase inhibitors diminished STAT3 activation and markedly abrogated the HDM-induced lung inflammation. These findings suggest that STAT3 acts as a novel epithelial regulator of the allergic response by altering Th2 cell recruitment and effector function, and thus, targeting this molecule may provide the basis for a novel asthma therapy.

In animals with acute airway inflammation followed by repeated exposure to inhaled Ag, inflammation wanes over time and thus limits the study of chronic airway inflammatory diseases such as asthma. We developed a model of airway inflammation and inhalational exposure to investigate regulatory pathways in the respiratory tract. We show that Th1- and Th2-induced airway inflammation followed by repeated exposure to inhaled Ag leads to a state of immunosuppression. Challenge of these animals with a marked population of TCR transgenic effector Th1 or Th2 cells results in a striking inhibition of inflammation and effector Th cells. In Th2 models, airway hyperresponsiveness, mucus, and eosinophilia are reduced. The inhibitory effects observed are Ag nonspecific, can be induced in lymphocyte-deficient mice, and are associated with a population of TGF-β1-expressing macrophages. Induction of this pathway may offer potent localized treatment of chronic T cell-mediated respiratory illnesses and provide insights into the development of such diseases.

It is increasingly recognized that asthma is a heterogeneous disease. Therefore, it is possible that analysis of gene expression in the airway will reveal clinically meaningful transcriptional endotypes of asthma (TEA clusters).We measured whole transcriptome gene expression profiles in the sputum and whole blood of 100 individuals with asthma and 12 control subjects using the Affymetrix HuGene ST 1.0 gene arrays. Unsupervised clustering was conducted using pathways from Kyoto Encyclopedia of Genes and Genomes (KEGG). This identified three TEA clusters that were correlated with clinical, physiologic, and inflammatory characteristics of the disease. TEA cluster 1 is a cluster of patients with asthma with a significantly higher rate of intubation (P = 0.05), a lower prebronchodilator FEV1 (P = 0.006), a higher bronchodilator response (P = 0.03), and higher exhaled nitric oxide levels (P = 0.04) than the other two TEA clusters. TEA cluster 2 has a higher rate of hospitalization for asthma (P = 0.04) and is heterogeneous. TEA cluster 3 is the largest cluster and has normal lung function, low exhaled nitric oxide levels, and lower inhaled steroid requirements. TEA cluster 1 had the highest sputum Th2 gene signature (IL-4, -5, and -13) compared with the other clusters. A classifier was developed that predicts TEA cluster assignment using 53 predictive genes in the circulation. The classifier was applied to gene expression data of children from the Asthma Biorepository for Integrative Genomic Exploration (Asthma BRIDGE) consortium cohort and confirmed that TEA clusters 1 and 2 are associated with history of intubation (P = 5.58 × 10(-06)) and hospitalization (P = 0.01), respectively.Analysis of the sputum transcriptome reveals three TEA clusters with different clinical and physiologic characteristics of disease in children and adults with asthma. This suggests that there are common transcriptomic signatures in the blood in children and adults with asthma that are associated with features of severe asthma.

TLRs have been studied extensively in the context of pathogen challenges, yet their role in the unchallenged lung is unknown. Given their direct interface with the external environment, TLRs in the lungs are prime candidates to respond to air constituents, namely particulates and oxygen. The mechanism whereby the lung maintains structural integrity in the face of constant ambient exposures is essential to our understanding of lung disease. Emphysema is characterized by gradual loss of lung elasticity and irreversible airspace enlargement, usually in the later decades of life and after years of insult, most commonly cigarette smoke. Here we show Tlr4(-/-) mice exhibited emphysema as they aged. Adoptive transfer experiments revealed that TLR4 expression in lung structural cells was required for maintaining normal lung architecture. TLR4 deficiency led to the upregulation of what we believe to be a novel NADPH oxidase (Nox), Nox3, in lungs and endothelial cells, resulting in increased oxidant generation and elastolytic activity. Treatment of Tlr4(-/- )mice or endothelial cells with chemical NADPH inhibitors or Nox3 siRNA reversed the observed phenotype. Our data identify a role for TLR4 in maintaining constitutive lung integrity by modulating oxidant generation and provide insights into the development of emphysema.

Chitin is a surface component of parasites and insects, and chitinases are induced in lower life forms during infections with these agents. Although chitin itself does not exist in humans, chitinases are present in the human genome. We show here that acidic mammalian chitinase (AMCase) is induced via a T helper-2 (Th2)–specific, interleukin-13 (IL-13)–mediated pathway in epithelial cells and macrophages in an aeroallergen asthma model and expressed in exaggerated quantities in human asthma. AMCase neutralization ameliorated Th2 inflammation and airway hyperresponsiveness, in part by inhibiting IL-13 pathway activation and chemokine induction. AMCase may thus be an important mediator of IL-13–induced responses in Th2-dominated disorders such as asthma.

To address the complex chronic effector properties of interleukin (IL)-10, we generated transgenic mice in which IL-10 was overexpressed in the lung. In these mice, IL-10 inhibited endotoxin-induced tumor necrosis factor production and neutrophil accumulation. IL-10 also caused mucus metaplasia, B and T cell-rich inflammation, and subepithelial fibrosis and augmented the levels of mRNA encoding Gob-5, mucins, and IL-13. In mice bred to have null mutations of IL-13, IL-4R(alpha), or STAT-6, transgenic IL-10 did not induce mucus metaplasia but did induce inflammation and fibrosis. IL-10 was also a critical mucin regulator of virus-induced mucus metaplasia. Thus, IL-10, although inhibiting lipopolysaccharide-induced inflammation, also causes mucus metaplasia, tissue inflammation, and airway fibrosis. These responses are mediated by multiple mechanisms with mucus metaplasia being dependent on and the inflammation and fibrosis being independent of an IL-13/IL-4R(alpha)/STAT-6 activation pathway.

Asthma is a common syndrome characterized by intermittent, reversible, airflow obstruction that is associated with airway hyperresponsiveness, mucus hypersecretion, and inflammation. With the advent of fiberscopic bronchoscopy, it has become possible to classify the nature of the cellular inflammation present in the airways of asthmatics. The balance of CD4 lymphocyte subsets, Th1 and Th2, is now recognized to be important in the pathogenesis of asthma. CD4 Th2 lymphocytes are central to the disease process and exert their effects through inflammatory cytokines that they release in response to activation by antigen. Th1 cells appear to be protective against the development of the disease. The treatment of asthma has traditionally been focused on decreasing inflammation and maximizing bronchodilation. Steroids and β-agonists have long since been the mainstay of therapy; however, there are now under investigation novel therapies targeted to inhibit specific proinflammatory mediators. Additionally, immunotherapy with repeated low-dose antigen exposure has had some promising results. The future of the treatment of asthma will be dependent on continued investigation into its pathogenesis.

Successful repair after tissue injury and inflammation requires resolution of the inflammatory response and removal of extracellular matrix breakdown products. We have examined whether the cell-surface adhesion molecule and hyaluronan receptor CD44 plays a role in resolving lung inflammation. CD44-deficient mice succumb to unremitting inflammation following noninfectious lung injury, characterized by impaired clearance of apoptotic neutrophils, persistent accumulation of hyaluronan fragments at the site of tissue injury, and impaired activation of transforming growth factor–β1. This phenotype was partially reversed by reconstitution with CD44+cells, thus demonstrating a critical role for this receptor in resolving lung inflammation.

The chitinase-like protein YKL-40 mediates airway inflammation and serum levels are associated with asthma severity. However, asthma phenotypes associated with YKL-40 levels have not been precisely defined.We conducted an unsupervised cluster analysis of asthma patients treated at the Yale Center for Asthma and Airways Disease (n=156) to identify subgroups according to YKL-40 level. The resulting YKL-40 clusters were cross-validated in cohorts from the Severe Asthma Research Programme (n=167) and the New York University/Bellevue Asthma Repository (n=341). A sputum transcriptome analysis revealed molecular pathways associated with YKL-40 subgroups.Four YKL-40 clusters (C1–C4) were identified. C3 and C4 had high serum YKL-40 levels compared with C1 and C2. C3 was associated with earlier onset and longer duration of disease, severe airflow obstruction, and near-fatal asthma exacerbations. C4 had the highest serum YKL-40 levels, adult onset and less airflow obstruction, but frequent exacerbations. An airway transcriptome analysis in C3 and C4 showed activation of non-type 2 inflammatory pathways.Elevated serum YKL-40 levels were associated with two distinct clinical asthma phenotypes: one with irreversible airway obstruction and another with severe exacerbations. The YKL-40 clusters are potentially useful for identification of individuals with severe or exacerbation-prone asthma.

Airway eosinophilia in asthma is dependent on cytokines secreted by Th2 cells, including IL-5 and IL-4. In these studies we investigated why the absence of IL-4 led to a reduction in airway, but not lung tissue, eosinophils. Using adoptively transferred, in vitro-generated TCR-transgenic Th2 cells deficient in IL-4, we show that this effect is independent of IL-5 and Th2 cell generation. Airway eosinophilia was no longer inhibited when IL-4−/− Th2 cells were transferred into IFN-γR−/− mice, indicating that IFN-γ was responsible for reducing airway eosinophils in the absence of IL-4. Intranasal administration of IFN-γ to mice after IL-4+/+ Th2 cell transfer also caused a reduction in airway, but not lung parenchymal, eosinophils. These studies show that IL-4 indirectly promotes airway eosinophilia by suppressing the production of IFN-γ. IFN-γ reduces airway eosinophils by engaging its receptor on hemopoietic cells, possibly the eosinophil itself. These studies capitalize on the complex counterregulatory effects of Th1 and Th2 cytokines in vivo and clarify how IL-4 influences lung eosinophilia. We define a new regulatory role for IFN-γ, demonstrating that eosinophilic inflammation is differentially regulated at distinct sites within the respiratory tract.