The Association Between Bronchiectasis and Chronic Obstructive Pulmonary Disease: Data from the European Bronchiectasis Registry (EMBARC).

RATIONALE AND OBJECTIVE: Bronchiectasis and COPD are associated conditions but misdiagnosis is believed to be common. A recently published international consensus definition of bronchiectasis (BE) and COPD association: The ROSE criteria (radiological bronchiectasis(R), obstruction: FEV1/FVC ratio<0.7 (O), symptoms (S) and exposure:≥10 pack year smoking (E) allows objective diagnosis of the BE-COPD association. METHODS: Analysis of the EMBARC registry, a prospective observational study of patients with CT confirmed bronchiectasis from 28 countries. The ROSE criteria were used to objectively defined BE-COPD association. Key outcomes during up to 5-years follow-up were exacerbations, hospitalization and mortality. MEASUREMENT AND MAIN RESULTS: 16730 patients with bronchiectasis were included. 4336 had a co-diagnosis of COPD and these patients had more exacerbations, worse quality of life and higher severity scores. We observed marked overdiagnosis of COPD using the ROSE criteria: 22.2% of patients with a diagnosis of COPD did not have airflow obstruction and 31.9% did not have a history of ≥10 pack years smoking. Therefore the proportion meeting the ROSE criteria for COPD was 2157 (55.4%). Compared to patients without COPD, patients meeting ROSE criteria had increased risk of exacerbations and exacerbations resulting in hospitalisation during follow-up (IRR 1.25 95%CI 1.15-1.35 and 1.69 95%CI 1.51-1.90 respectively) but patients with a diagnosis of COPD who did not meet ROSE criteria also had increased risk of exacerbations. CONCLUSIONS: The label of COPD is often applied to bronchiectasis patients without objective evidence of airflow obstruction and smoking history. Patients with a clinical label of COPD have worse clinical outcomes.

A discrete choice experiment to quantify the influence of trial features on the decision to participate in cystic fibrosis trials.

BACKGROUND: Patient-centred trial design optimises recruitment and retention, reduces trial failure rates and increases the diversity of trial cohorts. This allows safe and effective treatments to reach clinic more quickly. To achieve this, patients' views must be incorporated into trial design. METHODS: A discrete choice experiment was used to quantify preferences of pwCF for trials features; medicine type, trial location, stipend, washout, drug access on trial completion and trial design. Respondents were presented pairs of hypothetical trial scenarios with different level combinations assigned through experimental design. Respondents were asked to pick their preferred option or decline both. The cross-sectional data were explored using a Random Parameters Logit model. RESULTS: We received 207 eligible responses between Oct2020-Jan2021. The strongest influence on the decision to participate was trial location; pwCF favour participation at their usual clinical centre. Greater travel distances made respondents less willing to participate. Post-trial drug access ranked second. pwCF would rather participate in modulator trials than trials of other drugs. In general, pwCF did not favour a washout period, but were more prepared to washout non-modulators than modulators. Stipend provision was not ranked highly, but higher stipends increased intention to participate. Trial design (placebo vs open-label) had minimal influence on the decision to participate. There are complex interactions between placebos and washouts. CONCLUSIONS: We used quantitative methods to systematically elicit preferences of pwCF for clinical trials' features. We explore the relevance of our findings to trial design and delivery in the current CF trials landscape.

Biologically Relevant Murine Models of Chronic Pseudomonas aeruginosa Respiratory Infection.

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen and the leading cause of infection in patients with cystic fibrosis (CF). The ability of P. aeruginosa to evade host responses and develop into chronic infection causes significant morbidity and mortality. Several mouse models have been developed to study chronic respiratory infections induced by P. aeruginosa, with the bead agar model being the most widely used. However, this model has several limitations, including the requirement for surgical procedures and high mortality rates. Herein, we describe novel and adapted biologically relevant models of chronic lung infection caused by P. aeruginosa. Three methods are described: a clinical isolate infection model, utilising isolates obtained from patients with CF; an incomplete antibiotic clearance model, leading to bacterial bounce-back; and the establishment of chronic infection; and an adapted water bottle chronic infection model. These models circumvent the requirement for a surgical procedure and, importantly, can be induced with clinical isolates of P. aeruginosa and in wild-type mice. We also demonstrate successful induction of chronic infection in the transgenic ßENaC murine model of CF. We envisage that the models described will facilitate the investigations of host and microbial factors, and the efficacy of novel antimicrobials, during chronic P. aeruginosa respiratory infections.

Basic, translational and clinical aspects of bronchiectasis in adults.

Bronchiectasis is a common progressive respiratory disease with recognisable radiological abnormalities and a clinical syndrome of cough, sputum production and recurrent respiratory infections. Inflammatory cell infiltration into the lung, in particular neutrophils, is central to the pathophysiology of bronchiectasis. Herein we explore the roles and relationships between infection, inflammation and mucociliary clearance dysfunction in the establishment and progression of bronchiectasis. Microbial and host-mediated damage are important processes underpinning bronchiectasis and the relative contribution of proteases, cytokines and inflammatory mediators to the propagation of inflammation is presented. We also discuss the emerging concept of inflammatory endotypes, defined by the presence of neutrophilic and eosinophilic inflammation, and explore the role of inflammation as a treatable trait. Current treatment for bronchiectasis focuses on treatment of underlying causes, enhancing mucociliary clearance, controlling infection and preventing and treating complications. Data on airway clearance approaches via exercise and mucoactive drugs, pharmacotherapy with macrolides to decrease exacerbations and the usefulness of inhaled antibiotics and bronchodilators are discussed, finishing with a look to the future where new therapies targeting host-mediated immune dysfunction hold promise.

A systematic review to identify and collate factors influencing patient journeys through clinical trials.

Patient-centred trial design and delivery; improves recruitment and retention; increases participant satisfaction; encourages participation by a more representative cohort; and allows researchers to better meet participants' needs. Research in this area mostly focusses on narrow facets of trial participation. We aimed to systematically identify the breadth of patient-centred factors influencing participation and engagement in trials, and collate them into a framework. Through this we hoped to assist researchers to identify factors that could improve patient-centred trial design and delivery. Robust qualitative and mixed methods systematic reviews are becoming increasingly common in health research. The protocol for this review was prospectively registered on PROSPERO, CRD42020184886. We used the SPIDER (Sample, Phenomenon of Interest, Design, Evaluation, Research Type) framework as a standardised systematic search strategy tool. 3 databases were searched as well as references checking, and thematic synthesis was conducted. Screening agreement was performed and code and theme checking were conducted by 2 independent researchers. Data were drawn from 285 peer-reviewed articles. 300 discrete factors were identified, and sorted into 13 themes and subthemes. The full catalogue of factors is included in the Supplementary Material. A summary framework is included in the body of the article. This paper focusses on outlining common ground that themes share, highlighting critical features, and exploring interesting points from the data. Through this, we hope researchers from multiple specialities may be better able to meet patients' needs, protect patients' psychosocial wellbeing, and optimise trial recruitment and retention, with direct positive impact on research time and cost efficiency.

Taxonomic position, antibiotic resistance and virulence factor production by Stenotrophomonas isolates from patients with cystic fibrosis and other chronic respiratory infections.

BACKGROUND: The potential pathogenic role of Stenotrophomonas maltophilia in lung disease and in particular in cystic fibrosis is unclear. To develop further understanding of the biology of this taxa, the taxonomic position, antibiotic resistance and virulence factors of S. maltophilia isolates from patients with chronic lung disease were studied. RESULTS: A total of 111 isolates recovered between 2003 and 2016 from respiratory samples from patients in five different countries were included. Based on a cut-off of 95%, analysis of average nucleotide identity by BLAST (ANIb) showed that the 111 isolates identified as S. maltophilia by Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF/MS) belonged to S. maltophilia (n = 65), S. pavanii (n = 6) and 13 putative novel species (n = 40), which each included 1-5 isolates; these groupings coincided with the results of the 16S rDNA analysis, and the L1 and L2 ß-lactamase Neighbor-Joining phylogeny. Chromosomally encoded aminoglycoside resistance was identified in all S. maltophilia and S. pavani isolates, while acquired antibiotic resistance genes were present in only a few isolates. Nevertheless, phenotypic resistance levels against commonly used antibiotics, determined by standard broth microbroth dilution, were high. Although putative virulence genes were present in all isolates, the percentage of positive isolates varied. The Xps II secretion system responsible for the secretion of the StmPr1-3 proteases was mainly limited to isolates identified as S. maltophilia based on ANIb, but no correlation with phenotypic expression of protease activity was found. The RPF two-component quorum sensing system involved in virulence and antibiotic resistance expression has two main variants with one variant lacking 190 amino acids in the sensing region. CONCLUSIONS: The putative novel Stenotrophomonas species recovered from patient samples and identified by MALDI-TOF/MS as S. maltophilia, differed from S. maltophilia in resistance and virulence genes, and therefore possibly in pathogenicity. Revision of the Stenotrophomonas taxonomy is needed in order to reliably identify strains within the genus and elucidate the role of the different species in disease.

The Effect of CFTR Modulators on Airway Infection in Cystic Fibrosis.

The advent of Cystic fibrosis transmembrane receptor (CFTR) modulators in 2012 was a critical event in the history of cystic fibrosis (CF) treatment. Unlike traditional therapies that target downstream effects of CFTR dysfunction, CFTR modulators aim to correct the underlying defect at the protein level. These genotype-specific therapies are now available for an increasing number of CF patients, transforming the way we view the condition from a life-limiting disease to one that can be effectively managed. Several studies have demonstrated the vast improvement CFTR modulators have on normalization of sweat chloride, CFTR function, clinical endpoints, and frequency of pulmonary exacerbation. However, their impact on other aspects of the disease, such as pathogenic burden and airway infection, remain under explored. Frequent airway infections as a result of increased susceptibility and impaired innate immune response are a serious problem within CF, often leading to accelerated decline in lung function and disease progression. Current evidence suggests that CFTR modulators are unable to eradicate pathogenic organisms in those with already established lung disease. However, this may not be the case for those with relatively low levels of disease progression and conserved microbial diversity, such as young patients. Furthermore, it remains unknown whether the restorative effects exerted by CFTR modulators extend to immune cells, such as phagocytes, which have the potential to modulate the response of people with CF (pwCF) to infection. Throughout this review, we look at the potential impact of CFTR modulators on airway infection in CF and their ability to shape impaired pulmonary defences to pathogens.

Clinical characteristics of Pseudomonas and Aspergillus co-infected cystic fibrosis patients: A UK registry study.

BACKGROUND: Pseudomonas aeruginosa (Pa) and Aspergillus species (Asp) are the most common bacterial and fungal organisms respectively in CF airways. Our aim was to examine impacts of Asp infection and Pa/Asp co-infection. METHODS: Patients on the UK CF Registry in 2016 were grouped into: absent (Pa-), intermittent (Pai) or chronic Pa (Pac), each with Asp positive (Asp+) or negative (Asp-). Primary outcome was best percentage predicted FEV1 (ppFEV1) that year. Secondary outcomes were intravenous (IV) antibiotic courses, growth (height, weight, BMI) and additional disease complications. Associations between outcomes and infection-status were assessed using regression models adjusting for significant confounders (age, sex, Phe508del homozygosity and CF-related diabetes (CFRD)). RESULTS: 9,270 patients were included (median age 19 [IQR 9-30] years, 54% male, 50% Phe508del/F508del). 4,142 patients (45%) isolated Pa, 1,460 (16%) Asp. Pa-/Asp+ subjects had an adjusted ppFEV1 that was 5.9% lower than Pa-/Asp- (p < 0.0001). In patients with Pai or Pac, there was no additional impact of Asp on ppFEV1. However, there was a higher probability that Pac/Asp+ patients had required IV antibiotics than Pac/Asp- group (OR 1.23 [1.03-1.48]). Low BMI, ABPA, CF-liver disease and CFRD were all more frequent with Asp alone than Pa-/Asp-, though not more common in Pac/Asp+ than Pac/Asp-. CONCLUSIONS: Co-infection with Pa and Asp was not associated with reduced lung function compared with Pa alone, but was associated with additional use of IV antibiotics. Asp infection itself is associated with several important indicators of disease severity. Longitudinal analyses should explore the impact of co-infection on disease progression.

Criteria and definitions for the radiological and clinical diagnosis of bronchiectasis in adults for use in clinical trials: international consensus recommendations.

Bronchiectasis refers to both a clinical disease and a radiological appearance that has multiple causes and can be associated with a range of conditions. Disease heterogeneity and the absence of standardised definitions have hampered clinical trials of treatments for bronchiectasis and are important challenges in clinical practice. In view of the need for new therapies for non-cystic fibrosis bronchiectasis to reduce the disease burden, we established an international taskforce of experts to develop recommendations and definitions for clinically significant bronchiectasis in adults to facilitate the standardisation of terminology for clinical trials. Systematic reviews were used to inform discussions, and Delphi processes were used to achieve expert consensus. We prioritised criteria for the radiological diagnosis of bronchiectasis and suggest recommendations on the use and central reading of chest CT scans to confirm the presence of bronchiectasis for clinical trials. Furthermore, we developed a set of consensus statements concerning the definitions of clinical bronchiectasis and its specific signs and symptoms, as well as definitions for chronic bacterial infection and sustained culture conversion. The diagnosis of clinically significant bronchiectasis requires both clinical and radiological criteria, and these expert recommendations and proposals should help to optimise patient recruitment into clinical trials and allow reliable comparisons of treatment effects among different interventions for bronchiectasis. Our consensus proposals should also provide a framework for future research to further refine definitions and establish definitive guidance on the diagnosis of bronchiectasis.

BronchUK: protocol for an observational cohort study and biobank in bronchiectasis.

Bronchiectasis has been a largely overlooked disease area in respiratory medicine. This is reflected by a shortage of large-scale studies and lack of approved therapies, in turn leading to a variation of treatment across centres. BronchUK (Bronchiectasis Observational Cohort and Biobank UK) is a multicentre, prospective, observational cohort study working collaboratively with the European Multicentre Bronchiectasis Audit and Research Collaboration project. The inclusion criteria for patients entering the study are a clinical history consistent with bronchiectasis and computed tomography demonstrating bronchiectasis. Main exclusion criteria are 1) patients unable to provide informed consent, 2) bronchiectasis due to known cystic fibrosis or where bronchiectasis is not the main or co-dominant respiratory disease, 3) age <18 years, and 4) prior lung transplantation for bronchiectasis. The study is aligned to standard UK National Health Service (NHS) practice with an aim to recruit a minimum of 1500 patients from across at least nine secondary care centres. Patient data collected at baseline includes demographics, aetiology testing, comorbidities, lung function, radiology, treatments, microbiology and quality of life. Patients are followed up annually for a maximum of 5 years and, where able, blood and/or sputa samples are collected and stored in a central biobank. BronchUK aims to collect robust longitudinal data that can be used for analysis into current NHS practice and patient outcomes, and to become an integral resource to better inform future interventional studies in bronchiectasis.

Time to get serious about the detection and monitoring of early lung disease in cystic fibrosis.

Structural and functional defects within the lungs of children with cystic fibrosis (CF) are detectable soon after birth and progress throughout preschool years often without overt clinical signs or symptoms. By school age, most children have structural changes such as bronchiectasis or gas trapping/hypoperfusion and lung function abnormalities that persist into later life. Despite improved survival, gains in forced expiratory volume in one second (FEV1) achieved across successive birth cohorts during childhood have plateaued, and rates of FEV1 decline in adolescence and adulthood have not slowed. This suggests that interventions aimed at preventing lung disease should be targeted to mild disease and commence in early life. Spirometry-based classifications of 'normal' (FEV1≥90% predicted) and 'mild lung disease' (FEV1 70%-89% predicted) are inappropriate, given the failure of spirometry to detect significant structural or functional abnormalities shown by more sensitive imaging and lung function techniques. The state and readiness of two imaging (CT and MRI) and two functional (multiple breath washout and oscillometry) tools for the detection and monitoring of early lung disease in children and adults with CF are discussed in this article.Prospective research programmes and technological advances in these techniques mean that well-designed interventional trials in early lung disease, particularly in young children and infants, are possible. Age appropriate, randomised controlled trials are critical to determine the safety, efficacy and best use of new therapies in young children. Regulatory bodies continue to approve medications in young children based on safety data alone and extrapolation of efficacy results from older age groups. Harnessing the complementary information from structural and functional tools, with measures of inflammation and infection, will significantly advance our understanding of early CF lung disease pathophysiology and responses to therapy. Defining clinical utility for these novel techniques will require effective collaboration across multiple disciplines to address important remaining research questions. Future impact on existing management burden for patients with CF and their family must be considered, assessed and minimised.To address the possible role of these techniques in early lung disease, a meeting of international leaders and experts in the field was convened in August 2019 at the Australiasian Cystic Fibrosis Conference. The meeting entitiled 'Shaping imaging and functional testing for early disease detection of lung disease in Cystic Fibrosis', was attended by representatives across the range of disciplines involved in modern CF care. This document summarises the proceedings, key priorities and important research questions highlighted.

Discrete choice experiment (DCE) to quantify the influence of trial features on the decision to participate in cystic fibrosis (CF) clinical trials.

INTRODUCTION: Engaging people with cystic fibrosis (CF) in clinical trials is critical to improving outcomes for this fatal disease. Following extensive exploration of engagement in CF trials we believe six key concepts require a quantitative understanding of their influence in the current CF trials landscape including how controversial issues like placebos, washouts, stipend provision and location of trial visits are viewed by the CF community and how these might be modified depending on the type of medicine being investigated and the mechanism of access to the drug on trial completion. METHODS AND ANALYSIS: We have designed and will administer an online discrete choice experiment to elicit and quantify preferences of people with CF for these trials' attributes and estimate the relative importance of an attribute when choosing to participate in a trial. The cross-sectional data generated will be explored using conditional multinomial logit model. Mixed logit models such as the random-parameters logit and a latent class models will be used to explore preference heterogeneity. To determine the relative importance of an attribute, the difference between the attribute level with the highest preference weight and the level with the lowest preference weight will be calculated. ETHICS AND DISSEMINATION: Imperial College London Joint Research Compliance Office has granted ethical approval for this study. Patient consent will be sought following full explanation. No identifying information will be collected. Dissemination will be via international conferences, peer-review publication and patient accessible forums. Major CF trials networks have agreed to incorporate our findings into their review process, meaning our results can realistically influence and optimise CF trial delivery. PROSPERO REGISTRATION NUMBER: CRD42020184886.

Antimicrobial resistance: Concerns of healthcare providers and people with CF.

BACKGROUND: Chronic lung infections and their treatment pose risks for the development of antimicrobial resistance (AMR) in people with cystic fibrosis (PWCF). In this study, we evaluated the attitudes of healthcare providers' (HCP) and PWCF or their parents' toward AMR within the international CF community. METHODS: HCP and PWCF identified through listservs and CF-related organizations were asked to complete an AMR centered survey, with additional questions on antimicrobial stewardship (AMS) for HCP. Descriptive analyses are reported. RESULTS: The responding 443 HCP and 464 PWCF/Parents were from 30 and 25 countries, respectively. Sixty-two percent of HCP and 56% of PWCF stated they were "very concerned" about AMR, with Pseudomonas spp. and Burkholderia spp. considered the most concerning organisms for both HCP and PWCF/Parents. Non-tuberculous mycobacteria were of greater concern to HCP compared to PWCF/Parents. There was a discrepancy regarding AMR education to PWCF, with 80% of HCP stating having discussed this with PWCF/Parents, but only 50% of PWCF recalling such discussions. CONCLUSION: These results highlight that AMR is relevant to CF HCP and PWCF internationally, indicating that educational tools and research are warranted.

Efficacy and safety of TOBI Podhaler in Pseudomonas aeruginosa-infected bronchiectasis patients: iBEST study.

The study aimed to determine the efficacy of a safe and well-tolerated dose and regimen of tobramycin inhalation powder (TIP) on Pseudomonas aeruginosa sputum density in patients with bronchiectasis.This is a phase II, double-blind, randomised study in bronchiectasis patients aged ≥18 years with chronic P. aeruginosa infection. Patients were randomised 1:1:1 to either cohort A: three capsules of TIP once daily (84 mg); cohort B: five capsules once daily (140 mg) or cohort C: four capsules twice daily (224 mg). Within each cohort, patients were further randomised 2:2:1 either to TIP continuously, TIP cyclically (alternating 28 days of TIP and placebo) or placebo for 16 weeks, respectively and were followed up for 8 weeks.Overall, 107 patients were randomised to cohorts A (n=34), B (n=36) and C (n=37). All three TIP doses significantly reduced the P. aeruginosa sputum density from baseline to day 29 versus placebo in a dose-dependent manner (p≤0.0001, each). A smaller proportion of patients in the continuous-TIP (34.1%) and cyclical-TIP (35.7%) groups experienced pulmonary exacerbations versus placebo (47.6%) and also required fewer anti-pseudomonal antibiotics (38.6% on continuous TIP and 42.9% on cyclical TIP) versus placebo (57.1%) although not statistically significant. Pulmonary exacerbation of bronchiectasis was the most frequent (37.4%) adverse event. Overall, TIP was well tolerated, however, 23.4% of the patients discontinued the study drug due to adverse events.Continuous- and cyclical-TIP regimens with all three doses were safe and effective in reducing the P. aeruginosa sputum density in patients with bronchiectasis and chronic P. aeruginosa infection.

Toll like Receptor signalling by Prevotella histicola activates alternative NF-κB signalling in Cystic Fibrosis bronchial epithelial cells compared to P. aeruginosa.

Cystic Fibrosis (CF), caused by mutations affecting the CFTR gene, is characterised by viscid secretions in multiple organ systems. CF airways contain thick mucus, creating a gradient of hypoxia, which promotes the establishment of polymicrobial infection. Such inflammation predisposes to further infection, a self-perpetuating cycle in mediated by NF-κB. Anaerobic Gram-negative Prevotella spp. are found in sputum from healthy volunteers and CF patients and in CF lungs correlate with reduced levels of inflammation. Prevotella histicola (P. histicola) can suppress murine lung inflammation, however, no studies have examined the role of P. histicola in modulating infection and inflammation in the CF airways. We investigated innate immune signalling and NF-kB activation in CF epithelial cells CFBE41o- in response to clinical stains of P. histicola and Pseudomonas aeruginosa (P. aeruginosa). Toll-Like Receptor (TLR) expressing HEK-293 cells and siRNA assays for TLRs and IKKα were used to confirm signalling pathways. We show that P. histicola infection activated the alternative NF-kB signalling pathway in CF bronchial epithelial cells inducing HIF-1α protein. TLR5 signalling was responsible for the induction of the alternative NF-kB pathway through phosphorylation of IKKα. The induction of transcription factor HIF-1α was inversely associated with the induction of the alternative NF-kB pathway and knockdown of IKKα partially restored canonical NF-kB activation in response to P. histicola. This study demonstrates that different bacterial species in the respiratory microbiome can contribute differently to inflammation, either by activating inflammatory cascades (P. aeruginosa) or by muting the inflammatory response by modulating similar or related pathways (P. histicola). Further work is required to assess the complex interactions of the lung microbiome in response to mixed bacterial infections and their effects in people with CF.

A 2 × 2 factorial, randomised, open-label trial to determine the clinical and cost-effectiveness of hypertonic saline (HTS 6%) and carbocisteine for airway clearance versus usual care over 52 weeks in adults with bronchiectasis: a protocol for the CLEAR clinical trial.

BACKGROUND: Current guidelines for the management of bronchiectasis (BE) highlight the lack of evidence to recommend mucoactive agents, such as hypertonic saline (HTS) and carbocisteine, to aid sputum removal as part of standard care. We hypothesise that mucoactive agents (HTS or carbocisteine, or a combination) are effective in reducing exacerbations over a 52-week period, compared to usual care. METHODS: This is a 52-week, 2 × 2 factorial, randomized, open-label trial to determine the clinical effectiveness and cost effectiveness of HTS 6% and carbocisteine for airway clearance versus usual care - the Clinical and cost-effectiveness of hypertonic saline (HTS 6%) and carbocisteine for airway clearance versus usual care (CLEAR) trial. Patients will be randomised to (1) standard care and twice-daily nebulised HTS (6%), (2) standard care and carbocisteine (750 mg three times per day until visit 3, reducing to 750 mg twice per day), (3) standard care and combination of twice-daily nebulised HTS and carbocisteine, or (4) standard care. The primary outcome is the mean number of exacerbations over 52 weeks. Key inclusion criteria are as follows: adults with a diagnosis of BE on computed tomography, BE as the primary respiratory diagnosis, and two or more pulmonary exacerbations in the last year requiring antibiotics and production of daily sputum. DISCUSSION: This trial's pragmatic research design avoids the significant costs associated with double-blind trials whilst optimising rigour in other areas of trial delivery. The CLEAR trial will provide evidence as to whether HTS, carbocisteine or both are effective and cost effective for patients with BE. TRIAL REGISTRATION: EudraCT number: 2017-000664-14 (first entered in the database on 20 October 2017). ISRCTN.com, ISRCTN89040295. Registered on 6 July/2018. Funder: National Institute for Health Research, Health Technology Assessment Programme (15/100/01). SPONSOR: Belfast Health and Social Care Trust. Ethics Reference Number: 17/NE/0339. Protocol version: v3.0 Final_14052018.

Efficacy and safety of tobramycin inhalation powder in bronchiectasis patients with P. aeruginosa infection: Design of a dose-finding study (iBEST-1).

In patients with bronchiectasis (BE), infection with Pseudomonas aeruginosa (Pa) results in disease progression, frequent pulmonary exacerbations and lung function decline. However, at present, no inhaled antibiotics have been approved for the treatment of these patients. Tobramycin inhalation powder (TIP), approved for treatment of Pa infection in cystic fibrosis, could be a promising candidate. We aimed to assess effective and well-tolerated doses and regimens of TIP in BE patients with Pa infection. In this phase II, double-blind, placebo-controlled, randomised study, three different daily doses of TIP are administered either as continuous or cyclical regimens. The study protocol comprises 7-28 days of screening, 112 days of double-blind treatment and 56 days of follow-up. The plan was to enrol 180 patients (aged ≥18 years) with BE, documented Pa infection and a history of exacerbations. The primary outcome is change in sputum Pa density from baseline. Key secondary outcomes include number of pulmonary exacerbations, use of antipseudomonal antibiotics, serum and sputum tobramycin concentrations, quality of life and safety. Exploratory endpoints include lung clearance index, sputum inflammatory markers and microbiome analysis. As of October 2018, 107/180 patients were enrolled at 34 sites (six countries) following which recruitment was closed for administrative reasons unrelated to safety findings. Despite a reduced sample size from initially planned enrolment, the unique design may inform the benefit-risk profile of TIP in BE patients with chronic Pa infection. Moreover, several novel and exploratory endpoints (lung clearance index, inflammatory biomarkers, lung microbiome), will contribute to the advancement of research in this area.

The lung and gut microbiome: what has to be taken into consideration for cystic fibrosis?

The 15th European Cystic Fibrosis Society (ECFS) Basic Science pre-conference Symposium focused on the topic of the microbiome, asking the question "The lung and gut microbiome: what has to be considered for cystic fibrosis (CF)?" This review gives an overview of the main points raised during the symposium, which dealt with the technical considerations, pathophysiology and clinical implications of the microbiome in CF.

Geographic variation in the aetiology, epidemiology and microbiology of bronchiectasis.

Bronchiectasis is a disease associated with chronic progressive and irreversible dilatation of the bronchi and is characterised by chronic infection and associated inflammation. The prevalence of bronchiectasis is age-related and there is some geographical variation in incidence, prevalence and clinical features. Most bronchiectasis is reported to be idiopathic however post-infectious aetiologies dominate across Asia especially secondary to tuberculosis. Most focus to date has been on the study of airway bacteria, both as colonisers and causes of exacerbations. Modern molecular technologies including next generation sequencing (NGS) have become invaluable tools to identify microorganisms directly from sputum and which are difficult to culture using traditional agar based methods. These have provided important insight into our understanding of emerging pathogens in the airways of people with bronchiectasis and the geographical differences that occur. The contribution of the lung microbiome, its ethnic variation, and subsequent roles in disease progression and response to therapy across geographic regions warrant further investigation. This review summarises the known geographical differences in the aetiology, epidemiology and microbiology of bronchiectasis. Further, we highlight the opportunities offered by emerging molecular technologies such as -omics to further dissect out important ethnic differences in the prognosis and management of bronchiectasis.