Endotypes of Exacerbation in Bronchiectasis: An Observational Cohort Study.

RATIONALE: Bronchiectasis is characterised by acute exacerbations but the biological mechanisms underlying these events is poorly characterised. Objectives To investigate the inflammatory and microbial characteristics of exacerbations of bronchiectasis. METHODS: 120 patients with bronchiectasis were enrolled and presented with acute exacerbations within 12 months. Spontaneous sputum samples were obtained during a period of clinical stability and again at exacerbation prior to receipt of antibiotic treatment. A validated rapid PCR assay for bacteria and viruses was used to classify exacerbations as bacterial, viral or both. Sputum inflammatory assessments included label free Liquid chromography/mass spectrometry and measurement of sputum cytokines and neutrophil elastase activity. 16s rRNA sequencing was used to characterise the microbiome. MEASUREMENTS AND MAIN RESULTS: Bronchiectasis exacerbations showed profound molecular heterogeneity. At least one bacteria was identified in 103 samples (86%) and a high bacterial load (total bacterial load >10(7) copies/g) was observed in 81 patients (68%). Respiratory viruses were identified in 55 (46%) patients with rhinovirus being the most common virus (31%). PCR was more sensitive than culture. No consistent change in the microbiome was observed at exacerbation. Exacerbations were associated with increased neutrophil elastase, proteinase-3, Il-1beta and CXCL8. There markers were particularly associated with bacterial and bacterial+viral exacerbations. Distinct inflammatory and microbiome profiles were seen between different exacerbation subtypes, including bacterial, viral and eosinophilic events in both hypothesis led, and hypothesis-free analysis using integrated microbiome and proteomics, demonstrating 4 subtypes of exacerbation. CONCLUSION: Bronchiectasis exacerbations are heterogeneous events with contributions from bacteria, viruses and inflammatory dysregulation.

Airway IL-1ß is related to disease severity and mucociliary function in bronchiectasis.

RATIONALE: The inflammasome is a key regulatory complex of the inflammatory response leading to IL-1ß release and activation. IL-1ß amplifies inflammatory responses and induces mucus secretion and hyperconcentration in other diseases. The role of IL-1ß in bronchiectasis has not been investigated. OBJECTIVES: To characterize the role of airway IL-1ß in bronchiectasis including the association with mucus properties, ciliary function, airway inflammation, microbiome and disease severity. METHODS: Stable bronchiectasis patients were enrolled in an international cohort study (n=269). IL-1ß was measured in sputum supernatant. A validation cohort also had sputum rheology and hydration measured (n=53). For analysis, patients were stratified according to the median value of IL-1ß in the population (High versus Low) to compare disease severity, airway infection, microbiome (16S rRNA sequencing), inflammation and caspase-1 activity. Primary human nasal epithelial cells grown in air-liquid interface culture were used to study IL-1ß effect on cilia function. MEASUREMENTS AND MAIN RESULTS: Patients with high sputum IL-1ß had more severe disease, increased caspase-1 activity and increased Th1, Th2 and neutrophil inflammatory response compared with patients with low IL-1ß. The active-dominant form of IL-1ß was associated with increased disease severity. High IL-1ß was related to higher relative abundance of Proteobacteria in the microbiome and increased mucus solid content and viscoelastic properties. Chronic IL-1ß treatment reduced the functionality of cilia and tight junctions of epithelial cells in-vitro. CONCLUSIONS: A subset of stable bronchiectasis patients show increased airway IL-1ß, suggesting pulmonary inflammasome activation is linked with more severe disease, airway infection, mucus dehydration and epithelial dysfunction.

SFX-01 in hospitalised patients with community-acquired pneumonia during the COVID-19 pandemic: a double-blind, randomised, placebo-controlled trial.

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-1ß 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, log2FC >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.

Extensive acute and sustained changes to neutrophil proteomes post-SARS-CoV-2 infection.

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.

Dipeptidyl peptidase-1 inhibition in patients hospitalised with COVID-19: a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial.

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.

The protective effect of SARS-CoV-2 antibodies in Scottish healthcare workers.

BACKGROUND: Healthcare workers (HCWs) are believed to be at increased risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. It is not known to what extent the natural production of antibodies to SARS-CoV-2 is protective against re-infection. METHODS: A prospective observational study of HCWs in Scotland (UK) from May to September 2020 was performed. The Siemens SARS-CoV-2 total antibody assay was used to establish seroprevalence in this cohort. Controls, matched for age and sex to the general local population, were studied for comparison. New infections (up to 2 December 2020) post antibody testing were recorded to determine whether the presence of SARS-CoV-2 antibodies protects against re-infection. RESULTS: A total of 2063 health and social care workers were recruited for this study. At enrolment, 300 HCWs had a positive antibody test (14.5%). 11 out of 231 control sera tested positive (4.8%). HCWs therefore had an increased likelihood of a positive test (OR 3.4, 95% CI 1.85-6.16; p<0.0001). Dentists were most likely to test positive. 97.3% of patients who had previously tested positive for SARS-CoV-2 by reverse transcriptase (RT)-PCR had positive antibodies. 18.7% had an asymptomatic infection. There were 38 new infections with SARS-CoV-2 in HCWs who were previously antibody negative, and one symptomatic RT-PCR-positive re-infection. The presence of antibodies was therefore associated with an 85% reduced risk of re-infection with SARS-CoV-2 (hazard ratio 0.15, 95% CI 0.06-0.35; p=0.026). CONCLUSION: HCWs were three times more likely to test positive for SARS-CoV-2 than the general population. Almost all infected individuals developed an antibody response, which was 85% effective in protecting against re-infection with SARS-CoV-2.

Relationship between Symptoms, Exacerbations, and Treatment Response in Bronchiectasis.

Rationale: Bronchiectasis guidelines regard treatment to prevent exacerbation and treatment of daily symptoms as separate objectives.Objectives: We hypothesized that patients with greater symptoms would be at higher risk of exacerbations and therefore that a treatment aimed at reducing daily symptoms would also reduce exacerbations in highly symptomatic patients.Methods: Our study comprised an observational cohort of 333 patients from the East of Scotland (2012-2016). Either symptoms were modeled as a continuous variable or patients were classified as having high, moderate, or low symptom burden (>70, 40-70, and <40 using the St. George's Respiratory Questionnaire symptom score). The hypothesis that exacerbation reductions would only be evident in highly symptomatic patients was tested in a post hoc analysis of a randomized trial of inhaled dry powder mannitol (N = 461 patients).Measurements and Main Results: In the observational cohort, daily symptoms were a significant predictor of future exacerbations (rate ratio [RR], 1.10; 95% confidence interval [CI], 1.03-1.17; P = 0.005). Patients with higher symptom scores had higher exacerbation rates (RR, 1.74; 95% CI, 1.12-2.72; P = 0.01) over 12-month follow-up than those with lower symptoms. Inhaled mannitol treatment improved the time to first exacerbation (hazard ratio, 0.56; 95% CI, 0.40-0.77; P < 0.001), and the proportion of patients remaining exacerbation free for 12 months of treatment was higher in the mannitol group (32.7% vs. 14.6%; RR, 2.84; 95% CI, 1.40-5.76; P = 0.003), but only in highly symptomatic patients. In contrast, no benefit was evident in patients with lower symptom burden.Conclusions: Highly symptomatic patients have increased risk of exacerbations, and exacerbation benefit with inhaled mannitol was only evident in patients with high symptom burden.

Managing and preventing exacerbation of bronchiectasis.

PURPOSE OF REVIEW: Pulmonary exacerbations are key events in the natural history of bronchiectasis given their impact on quality of life, prognosis, and their contribution to healthcare costs. Preventing and managing exacerbations is a priority for clinicians and in this review, we discuss measures that should be utilized to achieve this aim. RECENT FINDINGS: Experts have proposed a focus on phenotyping and endotyping the bronchiectasis population to overcome the heterogeneity of this condition. Recent large studies of inhaled antibiotics and smaller studies of macrolides, which included exacerbation measures as their primary outcomes, have drawn further attention to this issue. SUMMARY: Exacerbations are currently treated with prolonged antibiotic treatment (10-14 days). Prevention of exacerbations requires a multidisciplinary approach which includes optimising airway clearance and treating underlying conditions. Patients who continue to experience exacerbations despite these measures may be offered chronic macrolide therapy or additional therapies based on identified treatable traits.

Development and initial validation of the bronchiectasis exacerbation and symptom tool (BEST).

BACKGROUND: Recurrent bronchiectasis exacerbations are related to deterioration of lung function, progression of the disease, impairment of quality of life, and to an increased mortality. Improved detection of exacerbations has been accomplished in chronic obstructive pulmonary disease through the use of patient completed diaries. These tools may enhance exacerbation reporting and identification. The aim of this study was to develop a novel symptom diary for bronchiectasis symptom burden and detection of exacerbations, named the BEST diary. METHODS: Prospective observational study of patients with bronchiectasis conducted at Ninewells Hospital, Dundee. We included patients with confirmed bronchiectasis by computed tomography, who were symptomatic and had at least 1 documented exacerbation of bronchiectasis in the previous 12 months to participate. Symptoms were recorded daily in a diary incorporating cough, sputum volume, sputum colour, dyspnoea, fatigue and systemic disturbance scored from 0 to 26. RESULTS: Twenty-one patients were included in the study. We identified 29 reported (treated exacerbations) and 23 unreported (untreated) exacerbations over 6-month follow-up. The BEST diary score showed a good correlation with the established and validated questionnaires and measures of health status (COPD Assessment Test, r = 0.61, p = 0.0037, Leicester Cough Questionnaire, r = - 0.52,p = 0.0015, St Georges Respiratory Questionnaire, r = 0.61,p < 0.0001 and 6 min walk test, r = - 0.46,p = 0.037). The mean BEST score at baseline was 7.1 points (SD 2.2). The peak symptom score during exacerbation was a mean of 16.4 (3.1), and the change from baseline to exacerbation was a mean of 9.1 points (SD 2.5). Mean duration of exacerbations based on time for a return to baseline symptoms was 15.3 days (SD 5.7). A minimum clinically important difference of 4 points is proposed. CONCLUSIONS: The BEST symptom diary has shown concurrent validity with current health questionnaires and is responsive at onset and recovery from exacerbation. The BEST diary may be useful to detect and characterise exacerbations in bronchiectasis clinical trials.

Validation of the COPD Assessment Test (CAT) as an Outcome Measure in Bronchiectasis.

BACKGROUND: Objective assessment of symptoms in bronchiectasis is important for research and in clinical practice. The COPD Assessment Test (CAT) is a short, simple assessment tool widely used in COPD. The items included in the CAT are not specific to COPD and also reflect the dominant symptoms of bronchiectasis. We therefore performed a study to validate the CAT as an outcome measure in bronchiectasis. METHODS: The CAT was administered to two cohorts of bronchiectasis patients along with other quality of life questionnaires. Patients underwent comprehensive clinical assessment. One cohort had repeated questionnaires collected before-and-after treatment of acute exacerbations. We analyzed convergent validity, repeatability, and responsiveness of the score and calculated the minimum clinically important difference (MCID) using a combination of distribution and anchor-based methods. RESULTS: In both cohorts there were positive correlations between the CAT and the St. George's Respiratory Questionnaire (r = 0.90, P < .0001 and r = 0.87, P < .0001). There was an inverse relationship between CAT and Quality of Life - Bronchiectasis Respiratory Symptoms Scale (r = -0.75, P < .0001) and Leicester Cough Questionnaire score (r = -0.77, P < .0001). Patients with more severe disease, based on the bronchiectasis severity index, had significantly higher CAT scores. CAT also correlated with FEV1 % predicted and 6-min walk distance (6MWD). CAT increased significantly at exacerbation and fell at recovery. The intraclass correlation coefficient for two measurements four-weeks apart while clinically stable was 0.88 (95% CI, 0.73-0.95, P < .0001). An MCID of 4 was most consistent. CONCLUSIONS: CAT is a valid, responsive symptom assessment tool in bronchiectasis. The MCID is estimated as 4 points.

Anti-Pseudomonas aeruginosa IgG antibodies and chronic airway infection in bronchiectasis.

BACKGROUND: Identification of chronic Pseudomonas aeruginosa (PA) infection is important in the management of bronchiectasis, but requires repeated sputum sampling. We hypothesized that serum anti-PA IgG antibodies could diagnose chronic PA infection at a single visit. METHODS: Clinically stable bronchiectasis patients were studied prospectively. Chronic PA infection was defined as 2 or more positive sputum samples at least 3 months apart and/or failure to clear PA following eradication treatment. Baseline serum anti-PA IgG was determined by a validated ELISA kit. RESULTS: A total of 408 patients were included. Sixty of them (14.7%) had chronic PA infection and had higher anti-PA IgG levels (median 6.2 vs. 1.3 units, p < 0.001). Antibody levels showed direct significant correlations with exacerbation frequency, the bronchiectasis severity index and sputum inflammatory markers. Fifty-seven patients with chronic PA infection had a positive test, giving 95% sensitivity, 74.4% specificity and AUROC of 0.87. During follow-up, 38 patients had a new PA isolation. Eradication at 12 months was achieved in 89.5% of subjects with a negative antibody test and 15.8% of patients with a positive test. CONCLUSIONS: Anti-PA IgG test is highly accurate to detect chronic PA infection in bronchiectasis patients. In addition, it may be a marker of disease severity and treatment response.

New therapies for the prevention and treatment of exacerbations of bronchiectasis.

PURPOSE OF REVIEW: Exacerbations of bronchiectasis have a major impact on quality of life, healthcare costs, and long-term risk of complications. Preventing exacerbations is one of the major goals of treatment. Bronchiectasis is increasingly recognized and the impact of bronchiectasis exacerbations on daily clinical practice is also increasing. RECENT FINDINGS: Preventing bronchiectasis exacerbations are dependent on appropriate risk assessment, identifying the patients at highest risk to rationally target preventive therapies. Inhaled and oral antibiotic treatments can target chronic bacterial infection which is one of the major risk factors for exacerbation. Although the data is weak, airway clearance is an important part of long-term management including in patients with frequent exacerbations. Anti-inflammatory therapies such as inhaled corticosteroids do not currently have a major role outside comorbid chronic obstructive pulmonary disease and asthma, but further studies are required. SUMMARY: Treatment of acute exacerbations involves prompt administration of antibiotic therapy with usually 14 days of oral, or for severe exacerbations, intravenous antibiotics. The role of corticosteroids is not established and there is little data on the optimal management approach for acute exacerbations. Home intravenous therapy can reduce healthcare costs and improve patient satisfaction with care. A number of large randomized controlled trials are currently enrolling or have recently completed raising the possibility that the treatment paradigm may change in the near future.

A Comprehensive Analysis of the Impact of Pseudomonas aeruginosa Colonization on Prognosis in Adult Bronchiectasis.

RATIONALE: Eradication and suppression of Pseudomonas aeruginosa is a key priority in national guidelines for bronchiectasis and is a major focus of drug development and clinical trials. An accurate estimation of the clinical impact of P. aeruginosa in bronchiectasis is therefore essential. METHODS: Data derived from 21 observational cohort studies comparing patients with P. aeruginosa colonization with those without it were pooled by random effects meta-analysis. Data were collected for key longitudinal clinical outcomes of mortality, hospital admissions, exacerbations, and lung function decline, along with cross-sectional outcomes such as quality of life. MEASUREMENTS AND MAIN RESULTS: In the aggregate, the included studies comprised 3,683 patients. P. aeruginosa was associated with a highly significant and consistent increase in all markers of disease severity, including mortality (odds ratio [OR], 2.95; 95% confidence interval [CI], 1.98-4.40; P < 0.0001), hospital admissions (OR, 6.57; 95% CI, 3.19-13.51; P < 0.0001), and exacerbations (mean difference, 0.97/yr; 95% CI, 0.64-1.30; P < 0.0001). The patients with P. aeruginosa also had worse quality of life on the basis of their St. George's Respiratory Questionnaire results (mean difference, 18.2 points; 95% CI, 14.7-21.8; P < 0.0001). Large differences in lung function and radiological severity were also observed. The definitions of colonization were inconsistent among the studies, but the findings were robust regardless of the definition used. CONCLUSION: P. aeruginosa is associated with an approximately threefold increased risk of death and an increase in hospital admissions and exacerbations in adult bronchiectasis.