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Rationale: Pseudomonas aeruginosa infection is associated with worse outcomes in bronchiectasis. Impaired neutrophil antimicrobial responses contribute to bacterial persistence. Gremubamab is a bivalent, bispecific monoclonal antibody targeting Psl exopolysaccharide and the type 3 secretion system component PcrV. Objectives: This study evaluated the efficacy of gremubamab to enhance killing of P. aeruginosa by neutrophils from patients with bronchiectasis and to prevent P. aeruginosa -associated cytotoxicity. Methods: P. aeruginosa isolates from a global bronchiectasis cohort ( n  = 100) underwent whole-genome sequencing to determine target prevalence. Functional activity of gremubamab against selected isolates was tested in vitro and in vivo . Patients with bronchiectasis ( n  = 11) and control subjects ( n  = 10) were enrolled, and the effect of gremubamab in peripheral blood neutrophil opsonophagocytic killing (OPK) assays against P. aeruginosa was evaluated. Serum antibody titers to Psl and PcrV were determined ( n  = 30; 19 chronic P. aeruginosa infection, 11 no known P. aeruginosa infection), as was the effect of gremubamab treatment in OPK and anti-cytotoxic activity assays. Measurements and Main Results: Psl and PcrV were conserved in isolates from chronically infected patients with bronchiectasis. Seventy-three of 100 isolates had a full psl locus, and 99 of 100 contained the pcrV gene, with 20 distinct full-length PcrV protein subtypes identified. PcrV subtypes were successfully bound by gremubamab and the monoclonal antibody-mediated potent protective activity against tested isolates. Gremubamab increased bronchiectasis patient neutrophil-mediated OPK (+34.6 ± 8.1%) and phagocytosis (+70.0 ± 48.8%), similar to effects observed in neutrophils from control subjects (OPK, +30.1 ± 7.6%). No evidence of competition between gremubamab and endogenous antibodies was found, with protection against P. aeruginosa -induced cytotoxicity and enhanced OPK demonstrated with and without addition of patient serum. Conclusions: Gremubamab enhanced bronchiectasis patient neutrophil phagocytosis and killing of P. aeruginosa and reduced virulence.

The 2023 European Respiratory Society Congress took place on a hybrid platform, with participants joining online and in-person in Milan, Italy. The congress welcomed over 20 000 attendees, bringing together exciting updates in respiratory science and medicine from around the world. In this article, early career members of Assembly 10 (Respiratory Infections) summarise a selection of sessions across a broad range of topics, including presentations on bronchiectasis, nontuberculous mycobacteria, tuberculosis, cystic fibrosis and coronavirus disease 2019., Competing Interests: Conflict of interest: F. Bindo reports no conflicts of interest. Conflict of interest: G. Fumagalli reports no conflicts of interest. Conflict of interest: K. Myroniuk-Konstantynovych reports no conflicts of interest. Conflict of interest: E. Papadopoulou reports no conflicts of interest. Conflict of interest: D. Paróczai reports no conflicts of interest. Conflict of interest: L. Perea reports no conflicts of interest. Conflict of interest: J. Pollock reports travel grants for conference attendance from Asthma+Lung UK, the American Thoracic Society, the European Respiratory Society and the British Association for Lung Research. Conflict of interest: O. Popovych reports no conflicts of interest. Conflict of interest: C. Premuda reports a European Respiratory Society Abstract Grant in Cystic Fibrosis. Conflict of interest: M.B. Long reports travel grants for conference attendance from Asthma+Lung UK, the British Thoracic Society and the American Thoracic Society. Conflict of interest: H.R. Keir reports honoraria received for lectures from Insmed Inc. and travel grants from Asthma+Lung UK for conference attendance., (Copyright ©The authors 2024.)

Introduction: Sulforaphane can induce the transcription factor, Nrf2, promoting antioxidant and anti-inflammatory responses. In this study, hospitalised patients with community-acquired pneumonia (CAP) were treated with stabilised synthetic sulforaphane (SFX-01) to evaluate impact on clinical status and inflammation., Methods: Double-blind, randomised, placebo-controlled trial of SFX-01 (300 mg oral capsule, once daily for 14 days) conducted in Dundee, UK, between November 2020 and May 2021. Patients had radiologically confirmed CAP and CURB-65 (confusion, urea >7 mmol·L -1 , respiratory rate ≥30 breaths·min -1 , blood pressure <90 mmHg (systolic) or ≤60 mmHg (diastolic), age ≥65 years) score ≥1. The primary outcome was the seven-point World Health Organization clinical status scale at day 15. Secondary outcomes included time to clinical improvement, length of stay and mortality. Effects on Nrf2 activity and inflammation were evaluated on days 1, 8 and 15 by measurement of 45 serum cytokines and mRNA sequencing of peripheral blood leukocytes., Results: The trial was terminated prematurely due to futility with 133 patients enrolled. 65 patients were randomised to SFX-01 treatment and 68 patients to placebo. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was the cause of CAP in 103 (77%) cases. SFX-01 treatment did not improve clinical status at day 15 (adjusted OR 0.87, 95% CI 0.41-1.83; p=0.71), time to clinical improvement (adjusted hazard ratio (aHR) 1.02, 95% CI 0.70-1.49), length of stay (aHR 0.84, 95% CI 0.56-1.26) or 28-day mortality (aHR 1.45, 95% CI 0.67-3.16). The expression of Nrf2 targets and pro-inflammatory genes, including interleukin (IL)-6, IL-1β and tumour necrosis factor-α, was not significantly changed by SFX-01 treatment. At days 8 and 15, respectively, 310 and 42 significant differentially expressed genes were identified between groups (false discovery rate adjusted p<0.05, log 2 FC >1)., Conclusion: SFX-01 treatment did not improve clinical status or modulate key Nrf2 targets in patients with CAP primarily due to SARS-CoV-2 infection., Competing Interests: Conflict of interest: H.R. Keir reports receiving personal fees for educational lecture from Insmed Inc., outside the submitted work. Conflict of interest: A.T. Dinkova-Kostova participates on the Evgen Pharma Scientific Advisory Board, outside the submitted work. Conflict of interest: J.D. Chalmers reports support for the present manuscript from Lifearc; grants or contracts from AstraZeneca, Genentech, Gilead Sciences, GlaxoSmithKline, Insmed, Grifols, Novartis and Boehringer Ingelheim, outside the submitted work; consulting fees from AstraZeneca, Chiesi, GlaxoSmithKline, Insmed, Grifols, Novartis, Boehringer Ingelheim, Pfizer, Janssen, Antabio and Zambon, outside the submitted work; and is an associate editor of this journal. Conflict of interest: The remaining authors have nothing to disclose., (Copyright ©The authors 2024.)

Background: Neutrophils are important in the pathophysiology of coronavirus disease 2019 (COVID-19), but the molecular changes contributing to altered neutrophil phenotypes following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are not fully understood. We used quantitative mass spectrometry-based proteomics to explore neutrophil phenotypes immediately following acute SARS-CoV-2 infection and during recovery., Methods: Prospective observational study of hospitalised patients with PCR-confirmed SARS-CoV-2 infection (May to December 2020). Patients were enrolled within 96 h of admission, with longitudinal sampling up to 29 days. Control groups comprised non-COVID-19 acute lower respiratory tract infection (LRTI) and age-matched noninfected controls. Neutrophils were isolated from peripheral blood and analysed using mass spectrometry. COVID-19 severity and recovery were defined using the World Health Organization ordinal scale., Results: Neutrophil proteomes from 84 COVID-19 patients were compared to those from 91 LRTI and 42 control participants. 5800 neutrophil proteins were identified, with >1700 proteins significantly changed in neutrophils from COVID-19 patients compared to noninfected controls. Neutrophils from COVID-19 patients initially all demonstrated a strong interferon signature, but this signature rapidly declined in patients with severe disease. Severe disease was associated with increased abundance of proteins involved in metabolism, immunosuppression and pattern recognition, while delayed recovery from COVID-19 was associated with decreased granule components and reduced abundance of metabolic proteins, chemokine and leukotriene receptors, integrins and inhibitory receptors., Conclusions: SARS-CoV-2 infection results in the sustained presence of circulating neutrophils with distinct proteomes suggesting altered metabolic and immunosuppressive profiles and altered capacities to respond to migratory signals and cues from other immune cells, pathogens or cytokines., Competing Interests: Conflict of interest: H.R. Keir has received speaker fees from Insmed. A. Shoemark has received grant funding from AstraZeneca. A.J. Brenes has received support for attending meetings from the British Society for Proteome research. J.D. Chalmers has received research grants from AstraZeneca, Boehringer Ingelheim, GlaxoSmithKline, Gilead Sciences, Grifols, Novartis, Insmed and Trudell, and received consultancy or speaker fees from Antabio, AstraZeneca, Boehringer Ingelheim, Chiesi, GlaxoSmithKline, Insmed, Janssen, Novartis, Pfizer, Trudell and Zambon. All other authors declare no conflicts of interest., (Copyright ©The authors 2024.)

Rationale: Although inflammation and infection are key disease drivers in bronchiectasis, few studies have integrated host inflammatory and microbiome data to guide precision medicine. Objectives: To identify clusters among patients with bronchiectasis on the basis of inflammatory markers and to assess the association between inflammatory endotypes, microbiome characteristics, and exacerbation risk. Methods: Patients with stable bronchiectasis were enrolled at three European centers, and cluster analysis was used to stratify the patients according to the levels of 33 sputum and serum inflammatory markers. Clusters were compared in terms of microbiome composition (16S ribosomal RNA sequencing) and exacerbation risk over a 12-month follow-up. Measurements and Main Results: A total of 199 patients were enrolled (109 [54.8%] female; median age, 69 yr). Four clusters of patients were defined according to their inflammatory profiles: cluster 1, milder neutrophilic inflammation; cluster 2, mixed-neutrophilic and type 2; cluster 3, most severe neutrophilic; and cluster 4, mixed-epithelial and type 2. Lower microbiome diversity was associated with more severe inflammatory clusters ( P  < 0.001), and β-diversity analysis demonstrated distinct microbiome profiles associated with each inflammatory cluster ( P  = 0.001). Proteobacteria and Pseudomonas at phylum and genus levels, respectively, were more enriched in clusters 2 and 3 than in clusters 1 and 4. Furthermore, patients in cluster 2 (rate ratio [RR], 1.49; 95% confidence interval [CI], 1.16-1.92) and cluster 3 (RR, 1.61; 95% CI, 1.12-2.32) were at higher risk of exacerbation over a 12-month follow-up compared with cluster 1, even after adjustment for prior exacerbation history. Conclusions: Bronchiectasis inflammatory endotypes are associated with distinct microbiome profiles and future exacerbation risk.

Bronchiectasis is a highly complex entity that can be very challenging to investigate and manage. Patients are diverse in their aetiology, symptoms, risk of complications and outcomes. "Endotypes"- subtypes of disease with distinct biological mechanisms, has been proposed as a means of better managing bronchiectasis. This review discusses the emerging field of endotyping in bronchiectasis. We searched PubMed and Google Scholar for randomized controlled trials (RCT), observational studies, systematic reviews and meta-analysis published from inception until October 2022, using the terms: "bronchiectasis", "endotypes", "biomarkers", "microbiome" and "inflammation". Exclusion criteria included commentaries and non-English language articles as well as case reports. Duplicate articles between databases were initially identified and appropriately excluded. Studies identified suggest that it is possible to classify bronchiectasis patients into multiple endotypes deriving from their co-morbidities or underlying causes to complex infective or inflammatory endotypes. Specific biomarkers closely related to a particular endotype might be used to determine response to treatment and prognosis. The most clearly defined examples of endotypes in bronchiectasis are the underlying causes such as immunodeficiency or allergic bronchopulmonary aspergillosis where the underlying causes are clearly related to a specific treatment. The heterogeneity of bronchiectasis extends, however, far beyond aetiology and it is now possible to identify subtypes of disease based on inflammatory mechanisms such airway neutrophil extracellular traps and eosinophilia. In future biomarkers of host response and infection, including the microbiome may be useful to guide treatments and to increase the success of randomized trials. Advances in the understanding the inflammatory pathways, microbiome, and genetics in bronchiectasis are key to move towards a personalized medicine in bronchiectasis., (Copyright © 2023 Sociedade Portuguesa de Pneumologia. All rights reserved.)

The European Respiratory Society International Congress took place both in person, in Barcelona, Spain, and online in 2022. The congress welcomed over 19 000 attendees on this hybrid platform, bringing together exciting updates in respiratory science and medicine from around the world. In this article, Early Career Members of the Respiratory Infections Assembly (Assembly 10) summarise a selection of sessions across a broad range of topics, including presentations on bronchiectasis, nontuberculous mycobacteria, tuberculosis, cystic fibrosis and coronavirus disease 2019., Competing Interests: Conflict of interest: K. Chichirelo-Konstantynovych declares support for attending the European Respiratory Society International Congress in 2022 as an invited Chair. H.R. Keir declares personal honoraria from Insmed Incorporated for providing an educational lecture in the 36 months prior to manuscript submission. All other authors declare no competing interests., (Copyright ©The authors 2023.)

Background: Neutrophil serine proteases are involved in the pathogenesis of COVID-19 and increased serine protease activity has been reported in severe and fatal infection. We investigated whether brensocatib, an inhibitor of dipeptidyl peptidase-1 (DPP-1; an enzyme responsible for the activation of neutrophil serine proteases), would improve outcomes in patients hospitalised with COVID-19., Methods: In a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial, across 14 hospitals in the UK, patients aged 16 years and older who were hospitalised with COVID-19 and had at least one risk factor for severe disease were randomly assigned 1:1, within 96 h of hospital admission, to once-daily brensocatib 25 mg or placebo orally for 28 days. Patients were randomly assigned via a central web-based randomisation system (TruST). Randomisation was stratified by site and age (65 years or ≥65 years), and within each stratum, blocks were of random sizes of two, four, or six patients. Participants in both groups continued to receive other therapies required to manage their condition. Participants, study staff, and investigators were masked to the study assignment. The primary outcome was the 7-point WHO ordinal scale for clinical status at day 29 after random assignment. The intention-to-treat population included all patients who were randomly assigned and met the enrolment criteria. The safety population included all participants who received at least one dose of study medication. This study was registered with the ISRCTN registry, ISRCTN30564012., Findings: Between June 5, 2020, and Jan 25, 2021, 406 patients were randomly assigned to brensocatib or placebo; 192 (47·3%) to the brensocatib group and 214 (52·7%) to the placebo group. Two participants were excluded after being randomly assigned in the brensocatib group (214 patients included in the placebo group and 190 included in the brensocatib group in the intention-to-treat population). Primary outcome data was unavailable for six patients (three in the brensocatib group and three in the placebo group). Patients in the brensocatib group had worse clinical status at day 29 after being randomly assigned than those in the placebo group (adjusted odds ratio 0·72 [95% CI 0·57-0·92]). Prespecified subgroup analyses of the primary outcome supported the primary results. 185 participants reported at least one adverse event; 99 (46%) in the placebo group and 86 (45%) in the brensocatib group. The most common adverse events were gastrointestinal disorders and infections. One death in the placebo group was judged as possibly related to study drug., Interpretation: Brensocatib treatment did not improve clinical status at day 29 in patients hospitalised with COVID-19., Funding: Sponsored by the University of Dundee and supported through an Investigator Initiated Research award from Insmed, Bridgewater, NJ; STOP-COVID19 trial., Competing Interests: Declaration of interests JDC reports grants and personal fees from AstraZeneca, Boehringer-Ingelheim, Chiesi, GSK, Gilead Sciences, Grifols, Insmed, Janssen, Novartis, and Zambon. CB reports grants from the UK National Institute for Health and Care Research Biomedical Research Centre during the conduct of the study; grants and personal fees from GSK, AstraZeneca, Chiesi, Boehringer-Ingelheim, Genentech, Roche, Sanofi, Regeneron, Merck, TEVA, Mologic, 4DPharma, and Novartis. AART reports grants and personal fees from British Heart Foundation and Actelion Pharmaceuticals. JU reports personal fees from Gilead Sciences and ViiV Healthcare and from Celltrion; and is supported by the UK Medical Research Council (MR/T023791/1). DPSD reports grants and personal fees from GSK, Vir Biotechnology, AstraZeneca, and Boehringer-Ingelheim. ASm has received non-financial support for clinical trial work from AstraZeneca, GSK, Chiesi, and Oncimmune; and has done consultancy work with AstraZeneca and GSK. MP reports non-financial support for clinical trial work from AstraZeneca, GSK, Chiesi, and Oncimmune and consultancy work with AstraZeneca and GSK. All other authors report no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

This article presents the highlights of the ERS Lung Science Conference 2022, including a session organised by the Early Career Member Committee (ECMC) dedicated to career development https://bit.ly/3tarCXc., Competing Interests: Conflict of interest: P.P.S.J. Khedoe received an ERS bursary for attendance at the Lung Science Conference 2022, which covered registration and hotel expenses. T.S. Kapellos received an ERS travel grant to attend the Lung Science Conference 2022 and the ERS Congress 2022. The remaining authors have no conflicts to disclose., (Copyright ©ERS 2022.)

Neisseria species are frequently identified in the bronchiectasis microbiome, but they are regarded as respiratory commensals. Using a combination of human cohorts, next-generation sequencing, systems biology, and animal models, we show that bronchiectasis bacteriomes defined by the presence of Neisseria spp. associate with poor clinical outcomes, including exacerbations. Neisseria subflava cultivated from bronchiectasis patients promotes the loss of epithelial integrity and inflammation in primary epithelial cells. In vivo animal models of Neisseria subflava infection and metabolipidome analysis highlight immunoinflammatory functional gene clusters and provide evidence for pulmonary inflammation. The murine metabolipidomic data were validated with human Neisseria-dominant bronchiectasis samples and compared with disease in which Pseudomonas-, an established bronchiectasis pathogen, is dominant. Metagenomic surveillance of Neisseria across various respiratory disorders reveals broader importance, and the assessment of the home environment in bronchiectasis implies potential environmental sources of exposure. Thus, we identify Neisseria species as pathobionts in bronchiectasis, allowing for improved risk stratification in this high-risk group., Competing Interests: Declaration of interests J.D.C. has received research grants from GSK, BI, AZ, Gilead Sciences, Grifols, and Insmed and has received personal fees from GSK, BI, AZ, Chiesi, Grifols, Napp, Novartis, Insmed, and Zambon, all outside the submitted work. S.H.C. is on advisory boards for CSL Behring, Pneumagen, and BI, serves on Data and Safety Monitoring Boards for Inovio Pharmaceuticals and Imam Abdulrahman Bin Faisal University, and has received personal fees from AZ, all outside of the submitted work., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Rationale: Bronchiectasis and chronic obstructive pulmonary disease (COPD) are two disease entities with overlapped clinical features, and codiagnosis frequently occurs (termed the "COPD-bronchiectasis association"). Objectives: To investigate the sputum microbiome and proteome in patients with bronchiectasis, COPD, and the COPD-bronchiectasis association with the aim of identifying endotypes that may inform treatment. Methods: Sputum microbiome and protein profiling were carried out using 16S rRNA amplicon sequencing and a label-free proteomics workflow, respectively, in a cohort comprising patients with COPD ( n  = 43), bronchiectasis ( n  = 30), and the COPD-bronchiectasis association ( n  = 48). Results were validated in an independent cohort of 91 patients ( n  = 28-31 each group) using targeted measurements of inflammatory markers, mucins, and bacterial culture. Measurements and Main Results: Principal component analysis of sputum microbiome and protein profiles showed a partial separation between the COPD and the "COPD-bronchiectasis association" group. Further analyses revealed that patients with the "COPD-bronchiectasis association" had a higher abundance of proteobacteria, higher expression of mucin-5AC and proteins from the "neutrophil degranulation" pathway compared to those with COPD. In contrast, patients with COPD had an elevated expression of mucin-5B and several peptidase inhibitors, higher abundance of common commensal taxa, and a greater microbiome diversity. The profiles of "COPD-bronchiectasis association" and bronchiectasis groups were largely overlapping. Five endotypes were proposed with differential inflammatory, mucin, and microbiological features. The key features related to the "COPD-bronchiectasis association" were validated in an independent cohort. Conclusions: Neutrophilic inflammation, differential mucin expression, and Gram-negative infection are dominant traits in patients with the "COPD-bronchiectasis association."

The European Respiratory Society International Congress 2021 took place virtually for the second year running due to the coronavirus pandemic. The Congress programme featured more than 400 sessions and 3000 abstract presentations, covering the entire field of respiratory science and medicine. In this article, early career members of the Respiratory Infections Assembly summarise a selection of sessions across a broad range of topics, including presentations on bronchiectasis, non-tuberculosis mycobacteria, tuberculosis, cystic fibrosis and COVID-19., Competing Interests: Conflict of interest: K.L. Horton reports receiving grants or contracts from a National Institute for Health Research Biomedical Research Centre and Wessex Medical Research joint PhD studentship, and was a member of the advisory board for Better Experimental Approaches to Treat PCD, a European Respiratory Society Clinical Research Collaboration; all disclosures made outside the submitted work. M.J. McDonnell reports receiving consulting fees by Bayer Pharmaceuticals for the Bronchiectasis Legacy Programme, honoraria received for lectures given at international events, and travel grants received from the Irish Thoracic Society and Newcastle University for attendance at European Respiratory Society Meetings; all disclosures made outside the submitted work. L. Perea reports receiving grants or contracts from an ERS Long-Term Research Fellowship outside the submitted work. M.R. Loebinger reports receiving consulting fees from Insmed, Parion, Astra Zeneca, Grifols and Armata; personal payments received for lectures, presentations, speaker bureaus, manuscript writing or educational events from Insmed and Grifols; and participation on data safety monitoring or advisory boards for Redhill, Biontech, SAB and Sage. The author is also ERS Group Chair. All disclosures made outside the submitted work. The remaining authors have nothing to disclose., (Copyright ©The authors 2022.)

Background: Nontuberculous mycobacterial (NTM) infections are difficult to diagnose and treat. Biomarkers to identify patients with active infection or at risk of disease progression would have clinical utility. Sputum is the most frequently used matrix for the diagnosis of NTM lung disease., Research Question: Can sputum proteomics be used to identify NTM-associated inflammatory profiles in sputum?, Study Design and Methods: Patients with NTM lung disease and a matched cohort of patients with COPD, bronchiectasis (BE), and cystic fibrosis (CF) without NTM lung disease were enrolled from two hospitals in the United Kingdom. Liquid chromatography-tandem mass spectrometry was used to identify proteomic biomarkers associated with underlying diagnosis (COPD, BE, and CF), the presence of NTM lung disease defined according to American Thoracic Society/Infectious Diseases Society of America criteria, and severity of NTM. A subset of patients receiving guideline-concordant NTM treatment were studied to identify protein changes associated with treatment response., Results: This study analyzed 95 sputum samples from 55 subjects (BE, n = 21; COPD, n = 19; CF, n = 15). Underlying disease and infection with Pseudomonas aeruginosa were the strongest drivers of sputum protein profiles. Comparing protein abundance in COPD, BE, and CF found that 12 proteins were upregulated in CF compared with COPD, including MPO, AZU1, CTSG, CAT, and RNASE3, with 21 proteins downregulated, including SCGB1A1, IGFBP2, SFTPB, GC, and CFD. Across CF, BE, and COPD, NTM infection (n = 15) was not associated with statistically significant differences in sputum protein profiles compared with those without NTM. Two proteins associated with iron chelation were significantly downregulated in severe NTM disease. NTM treatment was associated with heterogeneous changes in the sputum protein profile. Patients with NTM and a decrease in immune response proteins had a subjective symptomatic improvement., Interpretation: Sputum proteomics identified candidate biomarkers of NTM severity and treatment response. However, underlying lung disease and typical bacterial pathogens such as P aeruginosa are also key determinants of the sputum proteomic profile., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Rationale: Bronchiectasis is classically considered a neutrophilic disorder, but eosinophilic subtypes have recently been described. Objectives: To use multiple datasets available through the European Multicentre Bronchiectasis Audit and Research Collaboration to characterize eosinophilic bronchiectasis as a clinical entity focusing on the impact of eosinophils on bronchiectasis exacerbations. Methods: Patients were included from five countries to examine the relationships between blood eosinophil counts and clinical phenotypes after excluding coexisting asthma. 16S rRNA sequencing was used to examine relationships between eosinophil counts and the sputum microbiome. A post hoc analysis of the PROMIS (Inhaled Promixin in the Treatment of Non-Cystic Fibrosis Bronchiectasis) phase 2 trial was used to examine the impact of blood eosinophil counts on exacerbations in patients with Pseudomonas aeruginosa infection. Measurements and Main Results: A relationship between sputum and blood eosinophil counts was demonstrated in two cohorts. In analysis of 1,007 patients from five countries, 22.6% of patients had blood eosinophil counts of ⩾300 cells/μl. Counts of <100 cells/μl were associated with higher bronchiectasis severity and increased mortality. There was no clear relationship with exacerbations. Blood eosinophil counts of ⩾300 cells/μl were associated with both Streptococcus - and Pseudomonas -dominated microbiome profiles. To investigate the relationship of eosinophil counts with exacerbations after controlling for the confounding effects of infection, 144 patients were studied in a clinical trial after treatment with antipseudomonal antibiotics. Compared with patients with blood eosinophil counts of <100 cells/μl (reference), elevated eosinophil counts of 100-299 cells/μl (hazard ratio, 2.38; 95% confidence interval, 1.33-4.25; P  = 0.003) and ⩾300 cells/μl (hazard ratio, 3.99; 95% confidence interval, 2.20-7.85; P  < 0.0001) were associated with shorter time to exacerbation. Conclusions: Eosinophilic bronchiectasis affects approximately 20% of patients. After accounting for infection status, raised blood eosinophil counts are associated with shortened time to exacerbation.

Implemented control measures brought about by the coronavirus disease 2019 (COVID-19) pandemic have changed the prevalence of other respiratory viruses, often relegating them to a secondary plan. However, it must not be forgotten that a diverse group of viruses, including other human coronaviruses, rhinoviruses, respiratory syncytial virus, human metapneumoviruses, parainfluenza and influenza, continue to be responsible for a large burden of disease. In fact, they are among the most common causes of acute upper and lower respiratory tract infections globally. Viral respiratory infections can be categorised in several ways, including by clinical syndrome or aetiological agent. We describe their clinical spectrum. Distinctive imaging features, advances in microbiological diagnosis and treatment of severe forms are also discussed., Educational Aims: To summarise the knowledge on the spectrum of disease that respiratory viral infections can cause and recognise how often they overlap.To learn the most common causes of respiratory viral infections and acknowledge other less frequent agents that may target certain key populations ( e.g. immunocompromised patients).To improve awareness of the recent advances in diagnostic methods, including molecular assays and helpful features in imaging techniques.To identify supportive care strategies pivotal in the management of severe respiratory viral infections., Competing Interests: Conflict of interest: S. Castanhinha reports receiving a grant from Ordem dos Médicos for an ERS Paediatric Bronchoscopy course; consulting fees, and payment or honoraria for lectures, presentations, speakers’ bureaus, manuscript writing or educational events from Vertex Pharmaceuticals; support for attending meetings and/or travel from Zambon Pharma; participation on a Data Safety Monitoring Board or Advisory Board for Vertex Pharmaceuticals; and a leadership or fiduciary role in another board, society, committee or advocacy group for Comissão Coordenadora do Tratamento da Doença Fibrose Quística, all outside the submitted work. A. Silva-Pinto reports receiving a grant to his institution from Merck Sharp and Dohme; payment or honoraria for presentations received from Merck Sharp and Dohme, and from Gilead; and support for attending meetings and/or travel received from Merck Sharp and Dohme, ViiV Healthcare, and Gilead, all outside the submitted work. M. Tavares reports receiving support for attending meetings and/or travel from MDS Portugal, outside the submitted work. The remaining authors have nothing to disclose., (Copyright ©ERS 2022.)

Neutrophilic inflammation has a key role in the pathophysiology of multiple chronic lung diseases. The formation of neutrophil extracellular traps (NETs) has emerged as a key mechanism of disease in neutrophilic lung diseases including asthma, COPD, cystic fibrosis and, most recently, bronchiectasis. NETs are large, web-like structures composed of DNA and anti-microbial proteins that are able to bind pathogens, prevent microbial dissemination and degrade bacterial virulence factors. The release of excess concentrations of proteases, antimicrobial proteins, DNA and histones, however, also leads to tissue damage, impaired mucociliary clearance, impaired bacterial killing and increased inflammation. A number of studies have linked airway NET formation with greater disease severity, increased exacerbations and overall worse disease outcomes across the spectrum of airway diseases. Treating neutrophilic inflammation has been challenging in chronic lung disease because of the delicate balance between reducing inflammation and increasing the risk of infections through immunosuppression. Novel approaches to suppressing NET formation or the associated inflammation are in development and represent an important therapeutic target. This review will discuss the relationship between NETs and the pathophysiology of cystic fibrosis, asthma, COPD and bronchiectasis, and explore the current and future development of NET-targeting therapies., Competing Interests: Conflict of interest: H.R. Keir has nothing to disclose. Conflict of interest: J.D. Chalmers has received grants or contracts from AstraZeneca, Gilead Sciences, Boehringer Ingelheim, Novartis, Insmed and GlaxoSmithKline; consulting fees from AstraZeneca, Janssen, Boehringer Ingelheim, GlaxoSmithKline, Chiesi, Novartis, Insmed and Zambon; and payment or honoraria for lectures, presentations, speakers’ bureaus, manuscript writing or educational events from Boehringer Ingelheim., (Copyright ©The authors 2022.)

Background: Allergic bronchopulmonary aspergillosis (ABPA) is associated with frequent exacerbations and poor outcomes in chronic respiratory disease, but remains underdiagnosed. The role of fungal sensitization in bronchiectasis-COPD overlap (BCO) is unknown., Research Question: What is the occurrence and clinical relevance of Aspergillus sensitization and ABPA in BCO when compared with individuals with COPD or bronchiectasis without overlap?, Study Design: Prospective, observational, cross-sectional study., Methods: We prospectively recruited 280 patients during periods of clinical stability with bronchiectasis (n = 183), COPD (n = 50), and BCO (n = 47) from six hospitals across three countries (Singapore, Malaysia, and Scotland). We assessed sensitization responses (as specific IgE) to a panel of recombinant Aspergillus fumigatus allergens and the occurrence of ABPA in relationship to clinical outcomes., Results: Individuals with BCO show an increased frequency and clinical severity of ABPA compared with those with COPD and bronchiectasis without overlap. BCO-associated ABPA is associated with more severe disease, higher exacerbation rates, and lower lung function when compared with ABPA occurring in the absence of overlap. BCO with a severe bronchiectasis severity index (BSI; > 9) is associated significantly with the occurrence of ABPA that is unrelated to underlying COPD severity., Conclusions: BCO demonstrates a high frequency of ABPA that is associated with a severe BSI (> 9) and poor clinical outcomes. Clinicians should maintain a high index of suspicion for the potential development of ABPA in patients with BCO with high BSI., (Copyright © 2021 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

This article presents the ERS Early Career Member Award winner 2021 (@agbasteiro), and provides a brief description of the @EuroRespSoc Lung Science Conference 2022 and the Respiratory Channel https://bit.ly/2XTylbK., Competing Interests: Conflict of interest: None declared., (Copyright ©ERS 2021.)

Background: Breath analysis is a burgeoning field, with interest in volatile organic compounds (VOCs) as a noninvasive diagnostic tool or an outcome measure, but no randomised controlled trials (RCTs) have yet evaluated this technology in a clinical trial longitudinally. In a pilot RCT, our exploratory objectives were feasibility of measuring VOCs via multiple techniques, assessing relationships between VOCs and Haemophilus colonisation and whether CXCR2 antagonism with danirixin altered lung microbiome composition in individuals with COPD., Method: 43 participants had VOCs and sputum biomarkers evaluated. VOCs and induced sputum were collected after 6 h of fasting at screening and at days 1, 7 and 14. VOCs were analysed via gas chromatography mass spectrometry (GC-MS), field asymmetric ion mobility spectrometry (FAIMS) and eNose. The primary outcome for these analyses was the relationship between VOCs and Haemophilus abundance determined by 16S rRNA sequencing., Results: A joint-effects model demonstrated a modest relationship between four exhaled VOCs and Haemophilus relative abundance (R 2 =0.55) measured only by GC-MS, but not as measured using gas chromtaography FAIMS or eNose. There was considerable variability in absolute quantities of individual VOCs longitudinally., Conclusions: VOC measurement in clinical trials to identify subsets of COPD is feasible, but assessment of new VOC technologies must include concurrent GC-MS validation. Further work to standardise collection of VOCs and measuring a background or "housekeeper" VOC is required to understand and normalise individual VOC quantities., Competing Interests: Conflict of interest: D. Mohan is a current employee and shareholder of Genentech/Roche. Conflict of interest: H.R. Keir has nothing to disclose. Conflict of interest: H. Richardson has nothing to disclose. Conflict of interest: D. Mayhew is a former employee of and shareholder in GSK. Conflict of interest: J. Boyer is a former employee of and shareholder in GSK. Conflict of interest: M.P. van der Schee is an employee of Owlstone Medical Ltd and holds options in the company. Conflict of interest: M.D. Allsworth is an employee of Owlstone Medical Ltd and holds options in the company. Conflict of interest: B.E. Miller is a former employee of and shareholder in GSK. Conflict of interest: R. Tal-Singer is a former employee of and shareholder in GSK, and has received personal fees from Immunomet, Vocalis Health and Ena Respiratory. Conflict of interest: J.D. Chalmers reports grants and personal fees from GSK during the conduct of the study; and research grants from Boehringer Ingelheim (BI), AstraZeneca (AZ), Gilead Sciences, Grifols and Insmed, and has received personal fees from BI, AZ, Chiesi, Grifols, Napp, Novartis, Insmed and Zambon., (Copyright ©The authors 2021.)

The Global Initiative for Chronic Obstructive Lung Disease 2021 Report recommends inhaled corticosteroid (ICS)-containing regimens as part of pharmacological treatment in patients with chronic obstructive lung disease (COPD) and frequent exacerbations, particularly with eosinophilic inflammation. However, real-world studies reveal overprescription of ICS in COPD, irrespective of disease presentation and inflammatory endotype, leading to increased risk of side effects, mainly respiratory infections. The optimal use of ICS in COPD therefore remains an area of intensive research, and additional biomarkers of benefit and risk are needed. Although the interplay between inflammation and infection in COPD is widely acknowledged, the role of the microbiome in shaping lower airway inflammation has only recently been explored. Next-generation sequencing has revealed that COPD disease progression and exacerbation frequency are associated with changes in the composition of the lung microbiome, and that the immunosuppressive effects of ICS can contribute to potentially deleterious airway microbiota changes by increasing bacterial load and the abundance of potentially pathogenic taxa such as Streptococcus and Haemophilus . Here, we explore the relationship between microbiome, inflammation, ICS use and disease phenotype. This relationship may inform the benefit:risk assessment of ICS use in patients with COPD and lead to more personalised pharmacological management.

This article provides a brief description of some of the most remarkable sessions of the @EuroRespSoc Lung Science Conference and the Sleep and Breathing Conference 2021 and presents the new incoming members of the ECMC (@EarlyCareerERS) https://bit.ly/2RSDP40., Competing Interests: Conflict of interest: A.T. Goodwin has nothing to disclose. Conflict of interest: D. Karadoğan has nothing to disclose. Conflict of interest: M.M. De Santis has nothing to disclose. Conflict of interest: H.N. Alsafadi has nothing to disclose. Conflict of interest: I. Hawthorne has nothing to disclose. Conflict of interest: M. Bradicich has nothing to disclose. Conflict of interest: M. Siciliano has nothing to disclose. Conflict of interest: S. Şahin Duyar has nothing to disclose. Conflict of interest: A. Targa has nothing to disclose. Conflict of interest: M. Meszaros has nothing to disclose. Conflict of interest: M. Fanaridis has nothing to disclose. Conflict of interest: T. Gille reports personal fees from Boehringer Ingelheim, personal fees from Roche, other from Oxyvie (oxygen provider), other from LVL Medical (oxygen provider), other from Vitalaire (oxygen provider), outside the submitted work. Conflict of interest: H.R. Keir has nothing to disclose. Conflict of interest: C.C. Moor has nothing to disclose. Conflict of interest: M. Lichtblau has nothing to disclose. Conflict of interest: N.D. Ubags has nothing to disclose. Conflict of interest: J. Cruz has nothing to disclose., (Copyright ©ERS 2021.)

Bronchiectasis is a complex, heterogeneous disorder defined by both a radiological abnormality of permanent bronchial dilatation and a clinical syndrome. There are multiple underlying causes including severe infections, mycobacterial disease, autoimmune conditions, hypersensitivity disorders, and genetic conditions. The pathophysiology of disease is understood in terms of interdependent concepts of chronic infection, inflammation, impaired mucociliary clearance, and structural lung damage. Neutrophilic inflammation is characteristic of the disease, with elevated levels of harmful proteases such as neutrophil elastase associated with worse outcomes. Recent data show that neutrophil extracellular trap formation may be the key mechanism leading to protease release and severe bronchiectasis. Despite the dominant of neutrophilic disease, eosinophilic subtypes are recognized and may require specific treatments. Neutrophilic inflammation is associated with elevated bacterial loads and chronic infection with organisms such as Pseudomonas aeruginosa . Loss of diversity of the normal lung microbiota and dominance of proteobacteria such as Pseudomonas and Haemophilus are features of severe bronchiectasis and link to poor outcomes. Ciliary dysfunction is also a key feature, exemplified by the rare genetic syndrome of primary ciliary dyskinesia. Mucus symptoms arise through goblet cell hyperplasia and metaplasia and reduced ciliary function through dyskinesia and loss of ciliated cells. The contribution of chronic inflammation, infection, and mucus obstruction leads to progressive structural lung damage. The heterogeneity of the disease is the most challenging aspect of management. An understanding of the pathophysiology of disease and their biomarkers can help to guide personalized medicine approaches utilizing the concept of "treatable traits.", Competing Interests: None declared., (Thieme. All rights reserved.)

Background: Bronchiectasis is predominantly a neutrophilic inflammatory disease. There are no established therapies that directly target neutrophilic inflammation because little is understood of the underlying mechanisms leading to severe disease. Neutrophil extracellular trap (NET) formation is a method of host defence that has been implicated in multiple inflammatory diseases. We aimed to investigate the role of NETs in disease severity and treatment response in bronchiectasis., Methods: In this observational study, we did a series of UK and international studies to investigate the role of NETs in disease severity and treatment response in bronchiectasis. First, we used liquid chromatography-tandem mass spectrometry to identify proteomic biomarkers associated with disease severity, defined using the bronchiectasis severity index, in patients with bronchiectasis (n=40) in Dundee, UK. Second, we validated these biomarkers in two cohorts of patients with bronchiectasis, the first comprising 175 patients from the TAYBRIDGE study in the UK and the second comprising 275 patients from the BRIDGE cohort study from centres in Italy, Spain, and UK, using an immunoassay to measure NETs. Third, we investigated whether pathogenic bacteria had a role in NET concentrations in patients with severe bronchiectasis. In a separate study, we enrolled patients with acute exacerbations of bronchiectasis (n=20) in Dundee, treated with intravenous antibiotics for 14 days and proteomics were used to identify proteins associated with treatment response. Findings from this cohort were validated in an independent cohort of patients who were admitted to the same hospital (n=20). Fourth, to assess the potential use of macrolides to reduce NETs in patients with bronchiectasis, we examined two studies of long-term macrolide treatment, one in patients with bronchiectasis (n=52 from the UK) in which patients were given 250 mg of azithromycin three times a week for a year, and a post-hoc analysis of the Australian AMAZES trial in patients with asthma (n=47) who were given 500 mg of azithromycin 3 times per week for a year., Findings: Sputum proteomics identified that NET-associated proteins were the most abundant and were the proteins most strongly associated with disease severity. This finding was validated in two observational cohorts, in which sputum NETs were associated with bronchiectasis severity index, quality of life, future risk of hospital admission, and mortality. In a subgroup of 20 patients with acute exacerbations, clinical response to intravenous antibiotic treatment was associated with successfully reducing NETs in sputum. Patients with Pseudomonas aeruginosa infection had a lessened proteomic and clinical response to intravenous antibiotic treatment compared with those without Pseudomonas infections, but responded to macrolide therapy. Treatment with low dose azithromycin was associated with a significant reduction in NETs in sputum over 12 months in both bronchiectasis and asthma., Interpretation: We identified NETs as a key marker of disease severity and treatment response in bronchiectasis. These data support the concept of targeting neutrophilic inflammation with existing and novel therapies., Funding: Scottish Government, British Lung Foundation, and European Multicentre Bronchiectasis Audit and Research Collaboration (EMBARC)., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Infection is a key component of bronchiectasis pathophysiology. Characterisation of the microbiome offers a higher degree of sensitivity and resolution than does traditional culture methods. We aimed to evaluate the role of the microbiome in determining the risk of exacerbation and long-term outcomes, including all-cause mortality, in bronchiectasis., Methods: We did a prospective observational cohort study of patients with bronchiectasis from eastern Scotland. Patients were enrolled from Sept 11, 2012, to Dec 21, 2015, and followed until Jan 8, 2019, for long-term outcomes. Patients were included if they were aged 18 years or older, and had a high-resolution CT-confirmed diagnosis of bronchiectasis and clinical symptoms consistent with the disease. Sputum samples were obtained when patients were clinically stable. Repeat sputum samples were taken at stable and exacerbation visits during follow-up. The V3-V4 region of the bacterial 16S rRNA gene was sequenced using the Illumina MiSeq platform. The dominant bacterial genus in each sample was assigned on the basis of a previously published method. Microbiome characteristics were analysed for their association with measures of clinical disease severity and long-term outcomes using PERMANOVA, random forest, and survival analyses., Findings: Sequencing data were obtained from the sputum samples of 281 patients with bronchiectasis who were included in the stable baseline cohort. 49 (17%) of 281 patients provided more than one sample when clinically stable and were included in the longitudinal analysis. 64 (23%) patients provided both stable and exacerbation samples. In both stable bronchiectasis and during exacerbations, a sputum microbiome dominated by Proteobacteria and Firmicutes was observed. Individual patients' microbiome profiles were relatively stable over time, during exacerbations and at disease stability. Lower microbiome diversity, measured using the Shannon-Wiener diversity index, was associated with more severe bronchiectasis defined by the bronchiectasis severity index, lower FEV 1 , and more severe symptoms. Random forest analysis of baseline samples identified Pseudomonas, Enterobacteriaceae, and Stenotrophomonas as being associated with severe bronchiectasis (bronchiectasis severity index ≥9) and greater lung inflammation and Pseudomonas and Enterobacteriaceae with more frequent exacerbations. Patients in whom Pseudomonas was dominant (n=35) were at increased risk of all-cause mortality (hazard ratio 3·12, 95% CI 1·33-7·36; p=0·0091) and had more frequent exacerbations (incident rate ratio 1·69, 95% CI 1·07-2·67; p=0·024) during follow-up compared with patients with other dominant genera (n=246)., Interpretation: A reduction in microbiome diversity, particularly one associated with dominance of Pseudomonas, is associated with greater disease severity, higher frequency and severity of exacerbations, and higher risk of mortality. The microbiome might therefore identify subgroups of patients at increased risk of poor outcomes who could benefit from precision treatment strategies. Further research is required to identify the mechanisms of reduced microbiome diversity and to establish whether the microbiome can be therapeutically targeted., Funding: British Lung Foundation and European Respiratory Society EMBARC2 consortium., Competing Interests: Declaration of interests JDC reports research grants from AstraZeneca, Boehringer-Ingelheim, Chiesi, Gilead Sciences, GlaxoSmithKline, Insmed, Novartis, and Zambon. All other authors declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Bronchiectasis, a progressive chronic airway disease, is characterized by microbial colonization and infection. We present an approach to the multi-biome that integrates bacterial, viral and fungal communities in bronchiectasis through weighted similarity network fusion ( https://integrative-microbiomics.ntu.edu.sg ). Patients at greatest risk of exacerbation have less complex microbial co-occurrence networks, reduced diversity and a higher degree of antagonistic interactions in their airway microbiome. Furthermore, longitudinal interactome dynamics reveals microbial antagonism during exacerbation, which resolves following treatment in an otherwise stable multi-biome. Assessment of the Pseudomonas interactome shows that interaction networks, rather than abundance alone, are associated with exacerbation risk, and that incorporation of microbial interaction data improves clinical prediction models. Shotgun metagenomic sequencing of an independent cohort validated the multi-biome interactions detected in targeted analysis and confirmed the association with exacerbation. Integrative microbiomics captures microbial interactions to determine exacerbation risk, which cannot be appreciated by the study of a single microbial group. Antibiotic strategies probably target the interaction networks rather than individual microbes, providing a fresh approach to the understanding of respiratory infection.

Introduction: The chronic obstructive pulmonary disease (COPD) bacteriome associates with disease severity, exacerbations and mortality. While COPD patients are susceptible to fungal sensitisation, the role of the fungal mycobiome remains uncertain., Methods: We report the largest multicentre evaluation of the COPD airway mycobiome to date, including participants from Asia (Singapore and Malaysia) and the UK (Scotland) when stable (n=337) and during exacerbations (n=66) as well as nondiseased (healthy) controls (n=47). Longitudinal mycobiome analysis was performed during and following COPD exacerbations (n=34), and examined in terms of exacerbation frequency, 2-year mortality and occurrence of serum specific IgE (sIgE) against selected fungi., Results: A distinct mycobiome profile is observed in COPD compared with controls as evidenced by increased α-diversity (Shannon index; p<0.001). Significant airway mycobiome differences, including greater interfungal interaction (by co-occurrence), characterise very frequent COPD exacerbators (three or more exacerbations per year) (permutational multivariate ANOVA; adjusted p<0.001). Longitudinal analyses during exacerbations and following treatment with antibiotics and corticosteroids did not reveal any significant change in airway mycobiome profile. Unsupervised clustering resulted in two clinically distinct COPD groups: one with increased symptoms (COPD Assessment Test score) and Saccharomyces dominance, and another with very frequent exacerbations and higher mortality characterised by Aspergillus , Curvularia and Penicillium with a concomitant increase in serum sIgE levels against the same fungi. During acute exacerbations of COPD, lower fungal diversity associates with higher 2-year mortality., Conclusion: The airway mycobiome in COPD is characterised by specific fungal genera associated with exacerbations and increased mortality., Competing Interests: Conflict of interest: P.Y. Tiew has nothing to disclose. Conflict of interest: A.J. Dicker has nothing to disclose. Conflict of interest: H.R. Keir has nothing to disclose. Conflict of interest: M.E. Poh has nothing to disclose. Conflict of interest: S.L. Pang has nothing to disclose. Conflict of interest: M. Mac Aogáin has nothing to disclose. Conflict of interest: B.Q.Y. Chua has nothing to disclose. Conflict of interest: J.L. Tan has nothing to disclose. Conflict of interest: H. Xu has nothing to disclose. Conflict of interest: M.S. Koh has nothing to disclose. Conflict of interest: A. Tee has nothing to disclose. Conflict of interest: J.A. Abisheganaden has nothing to disclose. Conflict of interest: F.T. Chew reports personal fees for consultancy from Sime Darby Technology Centre, First Resources Ltd, Genting Plantation and Olam International, outside the submitted work. Conflict of interest: B.E. Miller is an employee and shareholder of GlaxoSmithKline. Conflict of interest: R. Tal-Singer reports personal fees from Immunomet and VOCALIS Health, outside the submitted work; and is a former employee and current shareholder of GlaxoSmithKline. Conflict of interest: J.D. Chalmers reports grants and personal fees from GlaxoSmithKline, Boehringer Ingelheim, AstraZeneca, Grifols and Insmed, grants from Gilead Sciences, personal fees from Chiesi, Napp, Novartis and Zambon, outside the submitted work. Conflict of interest: S.H. Chotirmall has nothing to disclose., (Copyright ©ERS 2021.)

Background: The sputum microbiome has a potential role in disease phenotyping and risk stratification in chronic obstructive pulmonary disease (COPD), but few large longitudinal cohort studies exist., Objective: Our aim was to investigate the COPD sputum microbiome and its association with inflammatory phenotypes and mortality., Methods: 16S ribosomal RNA gene sequencing was performed on sputum from 253 clinically stable COPD patients (4-year median follow-up). Samples were classified as Proteobacteria or Firmicutes (phylum level) and Haemophilus or Streptococcus (genus level) dominant. Alpha diversity was measured by using Shannon-Wiener diversity and Berger-Parker dominance indices. Survival was modeled by using Cox proportional hazards regression. A subset of 78 patients had label-free liquid chromatography with tandem mass spectrometry performed, with partial least square discriminant analysis integrating clinical, microbiome, and proteomics data., Results: Proteobacteria dominance and lower diversity was associated with more severe COPD according to the Global Initiative for Chronic Obstructive Lung Disease classification system (P = .0015), more frequent exacerbations (P = .0042), blood eosinophil level less than or equal to 100 cells/μL (P < .0001), and lower FEV 1 (P = .026). Blood eosinophil counts showed a positive relationship with percent of Firmicutes and Streptococcus and a negative association with percent Proteobacteria and Haemophilus. Proteobacteria dominance was associated with increased mortality compared with Firmicutes-dominated or balanced microbiome profiles (hazard ratio = 2.58; 95% CI = 1.43-4.66; P = .0017 and hazard ratio = 7.47; 95% CI = 1.02-54.86; P = .048, respectively). Integrated omics analysis showed significant associations between Proteobacteria dominance and the neutrophil activation pathway in sputum., Conclusion: The sputum microbiome is associated with clinical and inflammatory phenotypes in COPD. Reduced microbiome diversity, associated with Proteobacteria (predominantly Haemophilus) dominance, is associated with neutrophil-associated protein profiles and an increased risk of mortality., (Copyright © 2020 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

The implications of these findings are significant for development of CXCR2 antagonists and other mechanisms targeting neutrophil activation or NETosis, suggesting that IL-8-dependent mechanisms will only work in a subset of COPD patients https://bit.ly/32SeisO., Competing Interests: Conflict of interest: H.R. Keir has nothing to disclose. Conflict of interest: H. Richardson has nothing to disclose. Conflict of interest: C. Fillimore is an employee of and shareholder in GSK. Conflict of interest: A. Shoemark has nothing to disclose. Conflict of interest: A.L. Lazaar is an employee of and shareholder in GSK. Conflict of interest: B.E. Miller is an employee of and shareholder in GSK. Conflict of interest: R. Tal-Singer is a former employee of and current shareholder in GSK, and reports personal fees from Immunomet outside the submitted work. Conflict of interest: J.D. Chalmers reports grants from GSK during the conduct of the study; and grants and personal fees from AstraZeneca and Boehringer Ingelheim, grants from Gilead Sciences, grants and personal fees from Grifols and Insmed, and personal fees from GSK, Chiesi, Napp, Novartis and Zambon, outside the submitted work. Conflict of interest: D. Mohan is an employee of and shareholder in GSK., (Copyright ©ERS 2020.)

Background: Chitinase activity is an important innate immune defence mechanism against infection that includes fungi. The 2 human chitinases: chitotriosidase (CHIT1) and acidic mammalian chitinase are associated to allergy, asthma, and COPD; however, their role in bronchiectasis and bronchiectasis-COPD overlap (BCO) is unknown., Research Question: What is the association between chitinase activity, airway fungi and clinical outcomes in bronchiectasis and bronchiectasis-COPD overlap?, Study Design and Methods: A prospective cohort of 463 individuals were recruited across five hospital sites in three countries (Singapore, Malaysia, and Scotland) including individuals who were not diseased (n = 35) and who had severe asthma (n = 54), COPD (n = 90), bronchiectasis (n = 241) and BCO (n = 43). Systemic chitinase levels were assessed for bronchiectasis and BCO and related to clinical outcomes, airway Aspergillus status, and underlying pulmonary mycobiome profiles., Results: Systemic chitinase activity is elevated significantly in bronchiectasis and BCO and exceed the activity in other airway diseases. CHIT1 activity strongly predicts bronchiectasis exacerbations and is associated with the presence of at least one Aspergillus species in the airway and frequent exacerbations (≥3 exacerbations/y). Subgroup analysis reveals an association between CHIT1 activity and the "frequent exacerbator" phenotype in South-East Asian patients whose airway mycobiome profiles indicate the presence of novel fungal taxa that include Macroventuria, Curvularia and Sarocladium. These taxa, enriched in frequently exacerbating South-East Asian patients with high CHIT1 may have potential roles in bronchiectasis exacerbations., Interpretation: Systemic CHIT1 activity may represent a useful clinical tool for the identification of fungal-driven "frequent exacerbators" with bronchiectasis in South-East Asian populations., (Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)

Background: Identifying patients with COPD at increased risk of poor outcomes is challenging due to disease heterogeneity. Potential biomarkers need to be readily available in real-life clinical practice. Blood eosinophil counts are widely studied but few studies have examined the prognostic value of blood neutrophil counts (BNC)., Methods: In a large population-based COPD registry in the East of Scotland (TARDIS: Tayside Allergic and Respiratory Disease Information System), BNC were compared to measures of disease severity and mortality for up to 15 years follow-up. Potential mechanisms of disease modification by BNC were explored in a nested microbiome substudy., Results: 178,120 neutrophil counts were obtained from 7220 people (mean follow up 9 years) during stable disease periods. Median BNC was 5200cells/μL (IQR 4000-7000cells/μL). Mortality rates among the 34% of patients with elevated BNCs (defined as 6000-15000cells/μL) at the study start were 80% higher (14.0/100 person years v 7.8/100py, P < 0.001) than those with BNC in the normal range (2000-6000cells/μL). People with elevated BNC were more likely to be classified as GOLD D (46% v 33% P < 0.001), have more exacerbations (mean 2.3 v 1.3/year, P < 0.001), and were more likely to have severe exacerbations (13% vs. 5%, P < 0.001) in the following year. Eosinophil counts were much less predictive of these outcomes. In a sub-cohort (N = 276), patients with elevated BNC had increased relative abundance of Proteobacteria and reduced microbiome diversity., Conclusion: High BNC may provide a useful indicator of risk of exacerbations and mortality in COPD patients.

Rationale: PZP (pregnancy zone protein) is a broad-spectrum immunosuppressive protein believed to suppress T-cell function during pregnancy to prevent fetal rejection. It has not previously been reported in the airway. Objectives: To characterize PZP in the bronchiectasis airway, including its relationship with disease severity. Methods: Label-free liquid chromatography/mass spectrometry was performed for sputum protein profiling of patients with bronchiectasis confirmed by high-resolution computed tomography. Results for patients with and without Pseudomonas aeruginosa infection were compared. Sputum and serum PZP was measured by validated ELISA. Airway infection status was established by culture and 16S ribosomal RNA sequencing. Immunofluorescence, ELISA, and electron microscopy were used to identify the cellular source of PZP in neutrophils treated with multiple stimuli. Measurements and Main Results: Elevated PZP was identified by label-free liquid chromatography/mass spectrometry as being associated with P. aeruginosa infection. In a validation study of 124 patients, sputum but not serum concentrations of PZP were significantly associated with the Bronchiectasis Severity Index, the frequency of exacerbations, and symptoms. Airway infection with Proteobacteria such as P. aeruginosa was associated with higher concentrations of PZP. PZP in sputum was directly related to airway bacterial load. Neutrophils induced to form neutrophil extracellular traps (NETs) with phorbol myristate acetate released high concentrations of PZP in vitro , and fluorescence microscopy confirmed the presence of PZP in NETs, whereas fluorescence and electron microscopy localized PZP to the cytoplasm and nuclei of neutrophils. Effective antibiotic therapy reduced sputum PZP. Conclusions: PZP is released into NETs. We report a novel link between airway infection, NET formation, and disease severity in bronchiectasis during chronic airway inflammation.