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

Reliability of blood eosinophil count in steady-state bronchiectasis

RATIONALE

The baseline value of eosinophils in peripheral blood (BEC) has been associated with different degrees of severity, prognosis and response to treatment in patients with bronchiectasis. It is not known, however, if this basal value remains constant over time.

OBJECTIVES

The aim of this study was to assess whether the BEC remains stable in the long term in patients with bronchiectasis.

METHODS AND MEASUREMENTS

Patients from the RIBRON registry of bronchiectasis diagnosed by computed tomography with at least 2 BEC measurements one year apart were included in the study. Patients with asthma and those taking anti-eosinophilic drugs were excluded. Reliability was assessed using the intra-class correlation coefficient (ICC). A patient with a BEC of at least 300 cells/uL or less than 100 cells/uL was considered eosinophilic or eosinopenic, respectively. Group changes over time were also calculated.

MAIN RESULTS

Seven hundred and thirteen patients were finally included, with a mean age of 66.5 (13.2) years (65.8 % women). A total of 2701 BEC measurements were performed, with a median number of measurements per patient of 4 (IQR: 2-5) separated by a median of 12.1 (IQR: 10.5-14.3) months between two consecutive measurements. The ICC was good (>0.75) when calculated between two consecutive measurements (approximately one year apart) but had dropped significantly by the time of the next annual measurements. Similarly, the change from an eosinophilic or eosinopenic patient to a non-eosinophilic or non-eosinopenic patient, respectively, was less than 30 % during the first year with respect to the baseline value but was close to 50 % in later measurements.

CONCLUSIONS

Given the significant changes observed in the baseline value of the BEC over time, its monitoring is necessary in patients with bronchiectasis in order to more reliably assess its usefulness.

Non-Cystic Fibrosis Bronchiectasis in Adults: A Review

Importance

Non-cystic fibrosis (CF) bronchiectasis is a chronic lung condition caused by permanent bronchial dilatation and inflammation and is characterized by daily cough, sputum, and recurrent exacerbations. Approximately 500 000 people in the US have non-CF bronchiectasis.

Observations

Non-CF bronchiectasis may be associated with prior pneumonia, infection with nontuberculous mycobacteria or tuberculosis, genetic conditions (eg, α1-antitrypsin deficiency, primary ciliary dyskinesia), autoimmune diseases (eg, rheumatoid arthritis, inflammatory bowel disease), allergic bronchopulmonary aspergillosis, and immunodeficiency syndromes (eg, common variable immunodeficiency). Up to 38% of cases are idiopathic. According to US data, conditions associated with non-CF bronchiectasis include gastroesophageal reflux disease (47%), asthma (29%), and chronic obstructive pulmonary disease (20%). The prevalence of non-CF bronchiectasis increases substantially with age (7 per 100 000 in individuals 18-34 years vs 812 per 100 000 in those ≥75 years) and is more common in women than men (180 vs 95 per 100 000). Diagnosis is confirmed with noncontrast chest computed tomography showing dilated airways and often airway thickening and mucus plugging. Initial diagnostic evaluation involves blood testing (complete blood cell count with differential); immunoglobulin quantification testing (IgG, IgA, IgE, and IgM); sputum cultures for bacteria, mycobacteria, and fungi; and prebronchodilator and postbronchodilator spirometry. Treatment includes airway clearance techniques; nebulization of saline to loosen tenacious secretions; and regular exercise, participation in pulmonary rehabilitation, or both. Inhaled bronchodilators (β-agonists and antimuscarinic agents) and inhaled corticosteroids are indicated for patients with bronchiectasis who have asthma or chronic obstructive pulmonary disease. Exacerbations of bronchiectasis, which typically present with increased cough and sputum and worsened fatigue, are associated with progressive decline in lung function and decreased quality of life. Exacerbations should be treated with oral or intravenous antibiotics. Individuals with 3 or more exacerbations of bronchiectasis annually may benefit from long-term inhaled antibiotics (eg, colistin, gentamicin) or daily oral macrolides (eg, azithromycin). Lung transplant may be considered for patients with severely impaired pulmonary function, frequent exacerbations, or both. Among patients with non-CF bronchiectasis, mortality is higher for those with frequent and severe exacerbations, infection with Pseudomonas aeruginosa, and comorbidities, such as chronic obstructive pulmonary disease.

Conclusions and Relevance

Non-CF bronchiectasis is a chronic lung condition that typically causes chronic cough and daily sputum production. Exacerbations are associated with progressive decline in lung function and decreased quality of life. Management involves treatment of conditions associated with bronchiectasis, airway clearance techniques, oral or intravenous antibiotics for acute exacerbations, and consideration of long-term inhaled antibiotics or oral macrolides for patients with 3 or more exacerbations annually.

Phase 3 Trial of the DPP-1 Inhibitor Brensocatib in Bronchiectasis

BACKGROUND

In bronchiectasis, neutrophilic inflammation is associated with an increased risk of exacerbations and disease progression. Brensocatib, an oral, reversible inhibitor of dipeptidyl peptidase 1 (DPP-1), targets neutrophil serine proteases, key mediators of neutrophilic inflammation.

METHODS

In a phase 3, double-blind trial, we randomly assigned patients with bronchiectasis (in a 1:1:1 ratio for adults and a 2:2:1 ratio for adolescents) to receive brensocatib (10 mg or 25 mg once per day) or placebo. The primary end point was the annualized rate of adjudicated pulmonary exacerbations over a 52-week period. The secondary end points, listed in hierarchical testing order, were the time to the first exacerbation during the 52-week period; the percentage of patients remaining exacerbation-free at week 52; the change in forced expiratory volume in 1 second (FEV1); the annualized rate of severe exacerbations; and change in quality of life.

RESULTS

A total of 1721 patients (1680 adults and 41 adolescents) underwent randomization and received brensocatib or placebo. The annualized rate of pulmonary exacerbations was 1.02 in the 10-mg brensocatib group, 1.04 in the 25-mg brensocatib group, and 1.29 in the placebo group (rate ratio, brensocatib vs. placebo, 0.79 [95% confidence interval {CI}, 0.68 to 0.92; adjusted P = 0.004] with the 10-mg dose and 0.81 [95% CI, 0.69 to 0.94; adjusted P = 0.005] with the 25-mg dose). The hazard ratio for the time to the first exacerbation was 0.81 (95% CI, 0.70 to 0.95; adjusted P = 0.02) with the 10-mg dose and 0.83 (95% CI, 0.70 to 0.97; adjusted P = 0.04) with the 25-mg dose. In each brensocatib group, 48.5% of patients remained exacerbation-free at week 52, as compared with 40.3% in the placebo group (rate ratio, 1.20 [95% CI, 1.06 to 1.37; adjusted P = 0.02] with the 10-mg dose and 1.18 [95% CI, 1.04 to 1.34; adjusted P = 0.04] with the 25-mg dose). At week 52, FEV1 had declined by 50 ml with the 10-mg dose, 24 ml with the 25-mg dose, and 62 ml with placebo (least-squares mean difference vs. placebo, 11 ml [95% CI, -14 to 37; adjusted P = 0.38] with the 10-mg dose and 38 ml [95% CI, 11 to 65; adjusted P = 0.04] with the 25-mg dose). The incidence of adverse events was similar across groups, except for a higher incidence of hyperkeratosis with brensocatib.

CONCLUSIONS

Among patients with bronchiectasis, once-daily treatment with brensocatib (10 mg or 25 mg) led to a lower annualized rate of pulmonary exacerbations than placebo, and the decline in FEV1 was less with the 25-mg dose of brensocatib than with placebo. (Funded by Insmed; ASPEN ClinicalTrials.gov number, NCT04594369; EudraCT number, 2020-003688-25.).

Use of inhaled corticosteroids in bronchiectasis: data from the European Bronchiectasis Registry (EMBARC)

INTRODUCTION

Current bronchiectasis guidelines advise against the use of inhaled corticosteroids (ICS) except in patients with associated asthma, allergic bronchopulmonary aspergillosis (ABPA) and/or chronic obstructive pulmonary disease (COPD). This study aimed to describe the use of ICS in patients with bronchiectasis across Europe.

METHODS

Patients with bronchiectasis were enrolled into the European Bronchiectasis Registry from 2015 to 2022. Patients were grouped into ICS users and non-users at baseline and clinical characteristics associated with ICS use were investigated. Patients were followed up for clinical outcomes of exacerbation, hospitalisation and mortality for up to 5 years. We evaluated if elevated blood eosinophil counts (above the laboratory upper limit of normal) modified the effect of ICS on exacerbations.

RESULTS

19 324 patients were included for analysis and 10 109 (52.3%) were recorded as being prescribed ICS at baseline. After exclusion of patients with a history of asthma, COPD and/or ABPA, 3174/9715 (32.7%) patients with bronchiectasis were prescribed ICS. Frequency of ICS use varied across countries, ranging from 17% to 85% of included patients. ICS users had more severe disease, with significantly worse lung function, higher Bronchiectasis Severity Index scores and more frequent exacerbations at baseline (p<0.0001). Overall, ICS users did not have a reduced risk of exacerbation or hospitalisation during follow-up, but a significant reduction in exacerbation frequency was observed in the subgroup of ICS users with elevated blood eosinophil counts (relative risk 0.70, 95% CI 0.59 to 0.84, p<0.001).

CONCLUSION

ICS use is common in bronchiectasis, including in those not currently recommended ICS according to bronchiectasis guidelines. ICS use may be associated with reduced exacerbation frequency in patients with elevated blood eosinophils.

Effect of N-Acetylcysteine on Bronchiectasis in a Real-life Study. Data From the Spanish RIBRON Registry

INTRODUCTION

There is scarce information about the most used mucolytic drug in bronchiectasis N-acetylcysteine (N-AC). Our objective was to analyze the effect of N-AC with respect to some outcomes in bronchiectasis.

METHODS

Ambispective, longitudinal, observational, multi-center (43 centers) study of a cohort of 2461 adult patients diagnosed with bronchiectasis. Those patients treated in a stable situation with at least 600mg/d of N-AC (368; 15%) for at least 6 months were compared with patients not receiving this treatment. The variables analyzed and compared were those available two years before and after treatment. ANCOVA analysis was used to analyze the effect of N-AC as the inter-group difference of the basal intra-group difference for each variable, adjusted for relevant covariables.

RESULTS

The N-AC group showed a full adjusted improvement of 27% in exacerbations, 17% in hospitalizations, and 31% in total exacerbation rates compared with the no-N-AC group. Moreover, a decrease in the volume of sputum production of 59.7% was observed as well as a decrease of 12% of patients with bronchial infection by Pseudomonas aeruginosa (PA). The use of 1200mg/d (n=116) resulted in only a mild, albeit significative improvement in the exacerbation rate compared with the use of 600mg/d (-11% in absolute number). Both doses were well tolerated.

CONCLUSION

N-AC (in most cases at a dose of 600mg/d) is safe and effective and sufficient to reduce both the number of exacerbations and hospitalizations and the purulence and volume of sputum, as well as the isolation rate of PA in patients with bronchiectasis.

Neutrophilic inflammation in bronchiectasis

Noncystic fibrosis bronchiectasis, hereafter referred to as bronchiectasis, is a chronic, progressive lung disease that can affect people of all ages. Patients with clinically significant bronchiectasis have chronic cough and sputum production, as well as recurrent respiratory infections, fatigue and impaired health-related quality of life. The pathophysiology of bronchiectasis has been described as a vicious vortex of chronic inflammation, recurring airway infection, impaired mucociliary clearance and progressive lung damage that promotes the development and progression of the disease. This review describes the pivotal role of neutrophil-driven inflammation in the pathogenesis and progression of bronchiectasis. Delayed neutrophil apoptosis and increased necrosis enhance dysregulated inflammation in bronchiectasis and failure to resolve this contributes to chronic, sustained inflammation. The excessive release of neutrophil serine proteases, such as neutrophil elastase, cathepsin G and proteinase 3, promotes a protease-antiprotease imbalance that correlates with increased inflammation in bronchiectasis and contributes to disease progression. While there are currently no licensed therapies to treat bronchiectasis, this review will explore the evolving evidence for neutrophilic inflammation as a novel treatment target with meaningful clinical benefits.

Mediators of the association between allergic diseases and bronchiectasis: A bi-directional univariable and multivariable Mendelian randomization study and mediation analysis

Background

Emerging research indicates that bronchiectasis often coexists with a range of allergic illnesses. The pathogenesis of both conditions is highly complex, involving a variety of interconnected factors, such as immune responses, metabolic pathways, and gut microbiota. However, the precise causal relationship between bronchiectasis and allergy-related conditions remains poorly understood.

Materials and methods

We obtained published GWAS datasets for 5 allergic disorders (allergic asthma, allergic rhinitis, atopic conjunctivitis, atopic dermatitis, and chronic rhinosinusitis) and bronchiectasis, along with data on 731 immune cells, 91 inflammatory proteins, 1400 plasma metabolites, and 473 gut microbiotas. Using bi-directional two-sample Mendelian Randomization (TSMR), we explored causal relationships between allergic diseases and bronchiectasis and validated these findings in a replication cohort. We also applied Linkage Disequilibrium Score Regression (LDSC) to assess genetic correlations between the conditions. Additionally, the mediating effects of immune cells, inflammatory proteins, metabolites, and gut microbiota on the relationship between allergic disorders and bronchiectasis were assessed through two-step TSMR and multivariate MR analysis.

Results

Our study revealed that allergic asthma, allergic rhinitis, atopic conjunctivitis, and atopic dermatitis all increased the risk of developing bronchiectasis, with no causal relationship identified in the reverse direction. Additionally, positive genetic associations were observed between allergic asthma, allergic rhinitis, atopic dermatitis, and bronchiectasis, respectively. We identified a total of forty immune cells, 5 inflammatory proteins, ninety plasma metabolites, and nineteen gut microbiota species as causal factors contributing to bronchiectasis onset. In mediation analysis, we found that the metabolic ratio of Retinol (Vitamin A) to oleoyl-linoleoyl-glycerol (18:1 to 18:2) was a risk factor for allergic asthma developing bronchiectasis, while the level of CD14 on CD33dim HLA-DR + CD11b + cells was a risk factor for allergic rhinitis. Two specific metabolic ratios-the Aspartate to N-acetylglucosamine to N-acetylgalactosamine ratio and the Methionine to phosphate ratio-served as, respectively, risk and protective factors for atopic dermatitis-developing bronchiectasis.

Conclusion

Our findings suggest that allergic asthma, allergic rhinitis, atopic conjunctivitis, and atopic dermatitis increase the risk of developing bronchiectasis, with no evidence of a reverse causal relationship. Specifically, 3 metabolic ratios were identified as mediators between allergic diseases and bronchiectasis. Further studies are needed to clarify the underlying mechanisms.

Normative values for lung, bronchial sizes, and bronchus-artery ratios in chest CT scans: from infancy into young adulthood

OBJECTIVE

To estimate the developmental trends of quantitative parameters obtained from chest computed tomography (CT) and to provide normative values on dimensions of bronchi and arteries, as well as bronchus-artery (BA) ratios from preschool age to young adulthood.

MATERIALS AND METHODS

Two independent radiologists screened a dataset of 1160 chest CT scans, initially reported as normal, from participants aged 0 to 24 years. Using an automated deep learning-based algorithm, we computed the following bronchus and artery parameters: bronchial outer diameter (Bout), bronchial inner diameter (Bin), adjacent pulmonary artery diameter (A), bronchial wall thickness (Bwt), bronchial wall area (BWA), and bronchial outer area (BOA). From these parameters, we computed the following ratios: Bout/A, Bin/A, Bwt/A, Bwt/Bout, and BWA/BOA. Furthermore, mean lung density, total lung volume, and the square root of wall area of bronchi with a 10-mm lumen perimeter (Pi10) were obtained. The effects on CT parameters of age, sex, and iodine contrast were investigated using mixed-effects or regression model analyses.

RESULTS

375 normal inspiratory chest CT scans (females / males = 156 / 219; mean age [SD] 12.7 [5.0] years) met the inclusion criteria. Bout and Bin progressively increased with age (all p < 0.05), but Bwt, Bout/A, Bin/A, Bwt/A, Bwt/Bout, or BWA/BOA did not. Total lung volume and mean lung density continuously increased with age (both p < 0.001), while Pi10 did not exhibit such a trend. Bout, total lung volume, and mean lung density were the only parameters that differed between males and females, all higher in males than females (all p < 0.03). The presence of iodinated contrast led to greater values for Bwt, Bwt/Bout, and BWA/BOA, but lower values for Bin, Bout/A, Bin/A, and Bwt/A (all p < 0.01).

CONCLUSION

Quantitative CT parameters of both lung parenchyma and bronchi exhibit growth-related changes, but from 6 to 24 years ratios between bronchus and artery dimensions remain constant. Contrast-enhanced CT scans affect the assessment of lung parenchyma and bronchial size. We propose age and technique-dependent normative values for bronchial dimensions and wall thickness.

KEY POINTS

Question What are the developmental trends of quantitative lung CT parameters in patients from childhood into young adulthood? Findings The ratio between bronchus and pulmonary artery dimensions demonstrates consistent values across age groups, indicating synchronized growth between bronchi and paired pulmonary arteries. Clinical relevance Our findings highlight the importance of standardized CT protocol and volume acquisition, and emphasize the need for ongoing collection of normal chest CT scans to refine the proposed reference values.

Asthma and respiratory comorbidities

Asthma is a common respiratory condition with various phenotypes, nonspecific symptoms, and variable clinical course. The occurrence of other respiratory conditions with asthma, or respiratory comorbidities (RCs), is not unusual. A literature search of PubMed was performed for asthma and a variety of respiratory comorbidities for the years 2019 to 2024. The 5 conditions with the largest number of references, other than rhinitis and rhinosinusitis (addressed elsewhere), or that are the most problematic in the authors' clinical experience, are summarized. Others are briefly discussed. The diagnosis and treatment of both asthma and RCs are complicated by the overlap of symptoms and signs. Recognizing RCs is especially problematic in adult-onset, non-type 2 asthma because there are no biomarkers to assist in confirming non-type 2 asthma. Treatment decisions in subjects with suspected asthma and RCs are complicated by the potential similarities between the symptoms or signs of the RC and asthma, the absence of a sine quo non for the diagnosis of asthma, the likelihood that many RCs improve with systemic corticosteroid therapy, and the possibility that manifestations of the RCs are misattributed to asthma or vice versa. Recognition of RCs is critical to the effective management of asthma, particularly severe or difficult-to-treat asthma.

Artificial intelligence-driven volumetric CT outcome score in cystic fibrosis: longitudinal and multicenter validation with/without modulators treatment

OBJECTIVES

Holistic segmentation of CT structural alterations with 3D deep learning has recently been described in cystic fibrosis (CF), allowing the measurement of normalized volumes of airway abnormalities (NOVAA-CT) as an automated quantitative outcome. Clinical validations are needed, including longitudinal and multicenter evaluations.

MATERIALS AND METHODS

The validation study was retrospective between 2010 and 2023. CF patients undergoing Elexacaftor/Tezacaftor/Ivacaftor (ETI) or corticosteroids for allergic broncho-pulmonary aspergillosis (ABPA) composed the monocenter ETI and ABPA groups, respectively. Patients from six geographically distinct institutions composed a multicenter external group. All patients had completed CT and pulmonary function test (PFT), with a second assessment at 1 year in case of ETI or ABPA treatment. NOVAA-CT quantified bronchiectasis, peribronchial thickening, bronchial mucus, bronchiolar mucus, collapse/consolidation, and their overall total abnormal volume (TAV). Two observers evaluated the visual Bhalla score.

RESULTS

A total of 139 CF patients (median age, 15 years [interquartile range: 13-25]) were evaluated. All correlations between NOVAA-CT to both PFT and Bhalla score were significant in the ETI (n = 60), ABPA (n = 20), and External groups (n = 59), such as the normalized TAV (ρ ≥ 0.76; p < 0.001). In both ETI and ABPA groups, there were significant longitudinal improvements in peribronchial thickening, bronchial mucus, bronchiolar mucus and collapse/consolidation (p ≤ 0.001). An additional reversibility in bronchiectasis volume was quantified with ETI (p < 0.001). Intraclass correlation coefficient of reproducibility was > 0.99.

CONCLUSION

NOVAA-CT automated scoring demonstrates validity, reliability and responsiveness for monitoring CF severity over an entire lung and quantifies therapeutic effects on lung structure at CT, such as the volumetric reversibility of airway abnormalities with ETI.

CLINICAL RELEVANCE STATEMENT

Normalized volume of airway abnormalities at CT automated 3D outcome enables objective, reproducible, and holistic monitoring of cystic fibrosis severity over an entire lung for management and endpoints during therapeutic trials.

KEY POINTS

Visual scoring methods lack sensitivity and reproducibility to assess longitudinal bronchial changes in cystic fibrosis (CF). AI-driven volumetric CT scoring correlates longitudinally to disease severity and reliably improves with Elexacaftor/Tezacaftor/Ivacaftor or corticosteroid treatments. AI-driven volumetric CT scoring enables reproducible monitoring of lung disease severity in CF and quantifies longitudinal structural therapeutic effects.

Eosinopenia in bronchiectasis: A novel biomarker for morbidity and mortality

BACKGROUND

The paradigm of bronchiectasis is shifting away from its exclusive characterization as a neutrophilic condition. Patients with bronchiectasis and high eosinophil levels have been found to have a specific phenotype, but the clinical effect of eosinopenia remains unclear.

METHOD

A retrospective, single-center, observational study was conducted at a tertiary medical center. Adult patients under follow-up for bronchiectasis from January 2007 to August 2020 were categorized by blood eosinophil count (BEC) as follows: eosinopenia (<100 cells/µL), normal (100-299 cells/µL), and eosinophilia (≥300 cells/µL). Data on the first hospitalization due to exacerbation and the community exacerbation rate in the first year of follow-up were analyzed. Mortality rates were assessed up to the end of follow-up on September 1, 2023.

RESULTS

The cohort included 724 patients (100%), 61% female (n = 442), of mean age 61 ± 16 years. The median follow-up period was 7.5 years (IQR: 5.1-10.8). Eosinopenia was found in 14.7% (n = 107), normal BEC in 56.6% (n = 417), and eosinophilia in 28.7% (n = 200). Patients with eosinopenia had a higher hazard ratio for first hospitalization than the normal-count group (1.71, 95% CI 1.11-2.64, p = .01) and the highest mean exacerbation rate (p = .04). On multivariate analysis, eosinopenia was significantly associated with higher mortality (HR 2.15, 95% CI 1.42-3.24, p < .001) after adjusting for age and sex.

CONCLUSION

Eosinopenia in bronchiectasis emerged as a potential biomarker for adverse outcomes. Further study of its role in disease behavior may provide insights for the development of therapeutic strategies.

Disease Severity and Activity in Bronchiectasis: A Paradigm Shift in Bronchiectasis Management

Bronchiectasis has an increasing prevalence and substantial clinical and economic burden. Therefore, physicians should identify patients with bronchiectasis at high risk of disease progression to ensure optimal management in advance. The heterogeneity of bronchiectasis means it is unlikely that any single parameter could identify highrisk patients; therefore, disease severity is usually assessed using validated composite tools, such as the Bronchiectasis Severity Index, FACED, and Bronchiectasis Aetiology Comorbidity Index, to predict long-term outcomes in bronchiectasis. Disease severity, however, implies an advanced process with lung destruction. Earlier intervention may prevent disease progression and improve outcomes. To identify patients at risk, rather than patients with established advanced disease, we need to shift our focus from disease severity to disease activity. Disease activity denotes the activation level of underlying pathophysiological processes and can be measured using clinical presentations and biomarkers. This review discusses a paradigm shift in bronchiectasis management, focusing on disease activity rather than severity, to prevent disease progression.

Brensocatib in patients with bronchiectasis: subgroup analyses from the WILLOW trial

Introduction

Bronchiectasis is a chronic inflammatory airway disease. Brensocatib, an oral, reversible inhibitor of dipeptidyl peptidase 1 (DPP1), reduces pulmonary inflammation by preventing the activation of neutrophil serine proteases. In the phase II WILLOW trial, brensocatib prolonged time to first exacerbation in patients with bronchiectasis. In this post hoc analysis we compare clinical outcomes in patients from WILLOW according to baseline disease characteristics.

Methods

Adults with bronchiectasis treated with brensocatib (10 or 25 mg) or placebo once daily were analysed by baseline Bronchiectasis Severity Index (BSI) score (≤4 (mild), 5-8 (moderate), or ≥9 (severe)), exacerbation history (2 or ≥3 in the previous year), blood eosinophil count (<300 cells per µL or ≥300 cells per µL), long-term macrolide use (≥6 months; no or yes) and Pseudomonas aeruginosa culture at screening (negative or positive). End-points were time to first exacerbation, annualised exacerbation rate, change in lung function from baseline, and safety. All patients who received brensocatib were pooled and compared with placebo.

Results

Treatment with brensocatib versus placebo was associated with a longer time to first exacerbation (hazard ratio (95% confidence interval), BSI: ≤4, 0.28 (0.08-0.96); 5-8, 0.75 (0.35-1.60); ≥9, 0.61 (0.35-1.04); prior exacerbations: 2, 0.56 (0.34-0.90); ≥3, 0.71 (0.32-1.59); blood eosinophils per µL: <300, 0.66 (0.42-1.06); ≥300, 0.49 (0.20-1.20); long-term macrolide use: no, 0.60 (0.38-0.94); yes, 0.60 (0.25-1.45); P. aeruginosa culture: negative, 0.54 (0.32-0.92); positive, 0.68 (0.37-1.27)). Safety results were similar across subgroups.

Discussion

Patients treated with brensocatib had a numerically longer time to first exacerbation and reduced annualised rate of exacerbation versus placebo across all key baseline disease characteristics.

Prevalence and Clinical Implications of Pulmonary Vein Stenosis in Bronchiectasis: A 3D Reconstruction CT Study

BACKGROUND

Recent studies on bronchiectasis have revealed significant structural abnormalities and pathophysiological changes. However, there is limited research focused on pulmonary venous variability and congenital variation. Through our surgical observations, we noted that coarctation of pulmonary veins and atrophied lung volume are relatively common in bronchiectasis patients. Therefore, we conducted a retrospective study to explore pulmonary venous variation and secondary manifestations in bronchiectasis cases, utilizing 3D reconstruction software (Mimics Innovation Suite 21.0, Materialise Dental, Leuven, Belgium) to draw conclusions supported by statistical evidence.

METHOD

This retrospective study included patients with bronchiectasis and healthy individuals who underwent CT examinations at Beijing Chao-Yang Hospital between January 2017 and July 2023. Chest CT data were reconstructed using Materialise Mimics. Pulmonary veins and lung lobes were segmented from surrounding tissue based on an appropriate threshold determined by local grey values and image gradients. Subsequently, venous cross-sectional areas and lung volumes were measured for statistical analysis.

RESULT

CT data from 174 inpatients with bronchiectasis and 75 cases from the health examination center were included. Three-dimensional reconstruction data revealed a significant reduction in cross-sectional areas of pulmonary veins in the left lower lobe (p < 0.001), the right lower lobe (p = 0.030), and the right middle lobe (p = 0.009) of bronchiectasis patients. Subgroup analyses indicated that approximately 73.5% of localized cases of the left lower lobe exhibited pulmonary vein stenosis, while in the diffuse group, this proportion was only 52.6%. Furthermore, the cross-sectional area of pulmonary veins had a gradually decreasing trend, based on a small sample. Lung function tests showed significant reductions in FEV1, FVC, and FEV1% in bronchiectasis patients, attributed to the loss of lung volume in the left lower lobe, which accounted for 60.9% of the included sample.

CONCLUSIONS

Our recent findings suggest that pulmonary venous stenosis is a common variation in bronchiectasis and is often observed concurrently with reduced lung volume, particularly affecting the left lower lobe. Moreover, localized cases are more likely to suffer from pulmonary venous stenosis, with an ambiguous downtrend as the disease progresses. In conclusion, increased attention to pulmonary venous variation in bronchiectasis is warranted, and exploring new therapies to intervene in the early stages or alleviate obstruction may be beneficial.

Impact of Antipseudomonal Antibiotics in Patients with Bronchiectasis Who Experienced Exacerbation or Developed Pneumonia: A Nationwide Study in Japan

Background/Objectives: Although chronic infection by Pseudomonas aeruginosa among patients with bronchiectasis is associated with poor prognosis, the impact of antibiotics with P. aeruginosa coverage in patients with bronchiectasis who experienced bacterial pneumonia or exacerbation of bronchiectasis has not been fully investigated. Methods: This study targeted patients with bronchiectasis who were admitted to hospitals because of bacterial pneumonia or exacerbation of bronchiectasis between April 2018 and March 2020 using a national inpatient database in Japan. The association of antipseudomonal antibiotic treatment with in-hospital mortality was assessed after propensity score matching to adjust the patients' backgrounds. Results: In total, 4943 patients with bacterial pneumonia and 1914 patients with exacerbation of bronchiectasis were included in this study. The in-hospital mortality rate did not differ between patients who did and did not receive antipseudomonal agents among patients with bacterial pneumonia (9.0% [185/2045] vs. 7.4% [151/2045]; p = 0.053) and those with exacerbation of bronchiectasis (5.2% [42/803] vs. 4.1% [33/803] group; p = 0.287). Conclusions: The use of antibiotics covering P. aeruginosa does not apparently improve prognosis in patients with bacterial pneumonia or exacerbation of bronchiectasis. A prospective study focusing on the impact of antibiotics covering P. aeruginosa among patients with bronchiectasis in whom P. aeruginosa is isolated is required.

[CT imaging of chronic obstructive pulmonary disease: What aspects and what role?]

Chronic obstructive pulmonary disease (COPD), commonly defined as irreversible airflow limitation, is associated with specific morphological changes involving all three parts of the lung, namely the bronchi, parenchyma and pulmonary vessels. In vivo imaging, with its ability to describe the different types of lung alterations and their regional distribution, helps to elucidate the relationship between lung structure and respiratory function. High-resolution computed tomography (CT) of the lung is the imaging modality best suited to assessing the pathological changes associated with airflow obstruction occurring in COPD. Over the last few decades, numerous studies have demonstrated the role of CT as a morphological and functional method conducive to the phenotyping of COPD patients. This review proposes to examine the data on CT imaging of COPD with a critical approach to recent data, and to determine the extent to which CT could be integrated into care or clinical research on patients with this/these disease(s).

Effect of inspiratory lung volume on bronchial and arterial dimensions and ratios on chest computed tomography in patients with chronic obstructive pulmonary disease

BACKGROUND

The assessment of bronchus-artery (BA) metrics on chest CT is important for detecting airway abnormalities. It is less clear how BA metrics are dependent on lung volume.

METHODS

CTs were obtained from a COPDGene substudy investigating the impact of radiation dose on lung density. Patients with chronic obstructive pulmonary disease underwent a full-dose and a reduced-dose CT in the same imaging session. CTs were automatically analyzed by measuring diameters of the bronchial outer edge (Bout), bronchial inner wall (Bin), artery (A), and bronchial wall thickness (Bwt) from segmental (G0) and distal generations. BA ratios were computed: Bout/A, Bin/A, Bwt/A, and bronchial wall area/bronchial outer area (Bwa/Boa). The total lung volume of the CT (TLC-CT) was computed. Differences between the volumes between the two CTs were expressed as % of the highest TLC-CT (ΔTLC-CT%). For the BA metrics of each CT, we computed the median of measurements in G1-6. Mixed-effect models were used to investigate the influence of TLC-CT on BA metrics adjusted for dose protocol.

RESULTS

One thousand three hundred nineteen patients with a mean (SD) age of 64.4 (8.7) years were included. Three hundred twenty-nine (124) BA pairs were analyzed per CT. No significant difference was found for TLC-CT in relation to dose (p = 0.17). A ΔTLC-CT% of >10% (found in 121, 9%) led to 0.03 and 0.05 decreases in Bout/A and Bin/A and 0.008 and 0.11 decrease in log (Bwt/A) and log (Bwa/Boa), and a 0.03 increase in Bin and 0.06, 0.12, and 0.04 decrease in Bout, log (Bwt), and log (A) (all p < 0.001).

CONCLUSIONS

Variations in TLC over 10% between time points significantly influence bronchial dimensions, affecting BA metrics. Standardizing volumes is recommended for sensitive tracking of airway disease changes over time.

KEY POINTS

Question Are BA metrics dependent on total lung capacity (TLC), and if so, how? Findings TLC variations over 10% between time points significantly influence bronchial dimensions, affecting BA metrics. Variations below 10% between CT scans have little effect on BA metrics. Clinical relevance Small lung volume differences between chest CTs have little impact on bronchus and artery metrics; it is imperative to standardize chest CT lung volumes to ensure precise diagnosis and monitoring of airway disease.

Association of asthma and bronchiectasis: Mendelian randomization analyses and observational study

BACKGROUND

Previous studies have demonstrated that asthma is closely associated with bronchiectasis, however, the causal relationship between asthma and bronchiectasis has not been investigated in depth. Therefore, this study aims to explore the causal relationship and to identify potential factors that mediate between these two diseases.

METHOD

All the necessary summarized information were obtained from publicly available genome-wide association study (GWAS). Two-sample Mendelian randomization (two-sample MR) was employed to explore the causal relationship between asthma and bronchiectasis, with an additional dataset used for validation. Heterogeneity and pleiotropy analyses were utilized to verify the robustness of the results. Subsequently, mediation MR analyses were performed to identify potential mediating factors. Lastly, a retrospective observational study was conducted to validate the findings.

RESULT

Preliminary inverse-variance weighted (IVW) results indicated there was a causal effect of asthma on bronchiectasis (odds ratio [OR] = 1.228, 95% confidence interval [CI]: 1.077-1.400, P = 0.002). Repetition validation yielded a consistent result. Mediation MR analysis demonstrated that the presence of nasal polyps (OR = 1.063, 95% CI: 1.015-1.113, mediation ratio = 30.492%, P = 0.009), acute sinusitis (OR = 1.062, 95% CI: 1.009-1.118, mediation ratio = 30.157%, P = 0.018), chronic sinusitis (OR = 1.085, 95% CI: 1.024-1.150, mediation ratio = 40.677%, P = 0.005), and peripheral eosinophil counts (OR = 1.013, 95% CI: 1.000-1.026, mediation ratio = 6.514%, P = 0.042) served as significant mediators in the occurrence and development of bronchiectasis induced by asthma. Furthermore, a retrospective observational study observed that bronchiectasis patients with asthma had a higher prevalence of sinusitis (5.043% vs 2.971%, P < 0.001), nasal polyps (0.536% vs 0.152%, P < 0.001), and rhinitis (13.197% vs 1.860%, P < 0.001). The ratio (1.950 (0.500, 5.600) vs 1.500 (0.500, 2.600), P = 0.006) and counts (0.125 (0.040, 0.363) vs 0.090 (0.030, 0.160), P < 0.001) of peripheral blood eosinophils were also elevated in bronchiectasis patients with asthma.

CONCLUSION

The MR analysis uncovered a notable genetic association between asthma and bronchiectasis, which was partially mediated by sinusitis, nasal polyps, and eosinophils. A subsequent retrospective study provided further evidence by demonstrating that bronchiectasis patients with asthma had a higher prevalence of sinusitis, nasal polyps, an elevated proportion of eosinophils, and higher eosinophil counts.

The impact of Tanreqing injection on mucus hypersecretion and cough in bronchiectasis: A meta-analysis of randomized controlled trials

BACKGROUND

Bronchiectasis clinically manifests airway mucus hypersecretion as mucopurulent sputum production and chronic cough. In the past decade, Tanreqing injection (TRQ) has been often used in clinical practice as an add-on treatment for bronchiectasis in China. Several in vivo studies have indicated that TRQ is effective in improving sputum expectoration and cough in acute exacerbation of bronchiectasis but results of individual studies are inconsistent. Therefore, systematically and critically evaluating the effectiveness and safety of TRQ on mucus hypersecretion and cough in bronchiectasis is necessary.

METHODS

Randomized controlled trials examining the treatment of bronchiectasis with TRQ were systematically searched from databases including PubMed, Cochrane Library, Embase, Web of Science, Chinese National Knowledge Infrastructure, Vip Information Database, Wanfang data, and Chinese Biomedical Literature Database, based on a preregistered protocol and adhering to Cochrane methods. Pertinent data were taken out from the included studies and a methodological quality assessment was done. R language (version 4.4.1) was used to perform the meta-analysis.

RESULTS

Twenty randomized controlled trials involving 1544 patients were analyzed. The results demonstrated that TRQ significantly improved mucus hypersecretion, shortened the duration of cough and phlegm, reduced symptom scores, and enhanced both forced expiratory volume in 1 second and forced vital capacity. Additionally, TRQ effectively lowered inflammatory markers, including C-reactive protein, procalcitonin, white blood cell count, neutrophil count, interleukin-6, and tumor necrosis factor-alpha. Moreover, TRQ increased the partial pressure of oxygen and decreased carbon dioxide pressure.

CONCLUSION

The findings suggest that TRQ positively impacts mucus hypersecretion and mucociliary clearance, leading to improvements in sputum production and cough during bronchiectasis exacerbations, without increasing the risk of adverse effects. TRQ may be considered a viable option for managing bronchiectasis and could serve as a novel mucus-modifying agent.

Automated method of bronchus and artery dimension measurement in an adult bronchiectasis population

Aim

Bronchiectasis (BE) is a disease defined by irreversible dilatation of the airway. Computed tomography (CT) plays an important role in the detection and quantification of BE. The aim of this study was three-fold: 1) to assess bronchus-artery (BA) dimensions using fully automated software in a cohort of BE disease patients; 2) to compare BA dimensions with semi-quantitative BEST-CT (Bronchiectasis Scoring Technique for CT) scores for BE and bronchial wall thickening; and 3) to explore the structure-function relationship between BA-method lumen dimensions and spirometry outcomes.

Methods

Baseline CTs of BE patients who participated in a clinical trial were collected retrospectively. CTs were analysed manually with the BEST-CT scoring system and automatically using LungQ (v.2.1.0.1, Thirona, The Netherlands), which measures the following BA dimensions: diameters of bronchial outer wall (Bout), bronchial inner wall (Bin) and artery (A), and bronchial wall thickness (Bwt) and computes BA ratios (Bout/A and Bin/A) to assess bronchial widening. To assess bronchial wall thickness, we used the Bwt/A ratio and the ratio between the bronchus wall area (Bwa) and the area defined by the outer airway (Boa) (Bwa/Boa).

Results

In total, 65 patients and 16 900 BA pairs were analysed by the automated BA method. The median (range) percentage of BA pairs defined as widened was 69 (55-84)% per CT using a cut-off value of 1.5 for Bout/A, and 53 (42-65)% of bronchial wall were thickened using a cut-off value of 0.14 for Bwt/A. BA dimensions were correlated with comparable outcomes for the BEST-CT scoring method with a correlation coefficient varying between 0.21 to 0.51. The major CT BA determinants of airflow obstruction were bronchial wall thickness (p=0.001) and a narrower bronchial inner diameter (p=0.003).

Conclusion

The automated BA method, which is an accurate and sensitive tool, demonstrates a stronger correlation between visual and automated assessment and lung function when using a higher cut-off value to define bronchiectasis.

[Management of adult bronchiectasis - Consensus-based Guidelines for the German Respiratory Society (DGP) e. V. (AWMF registration number 020-030)]

Bronchiectasis is an etiologically heterogeneous, chronic, and often progressive respiratory disease characterized by irreversible bronchial dilation. It is frequently associated with significant symptom burden, multiple complications, and reduced quality of life. For several years, there has been a marked global increase in the prevalence of bronchiectasis, which is linked to a substantial economic burden on healthcare systems. This consensus-based guideline is the first German-language guideline addressing the management of bronchiectasis in adults. The guideline emphasizes the importance of thoracic imaging using CT for diagnosis and differentiation of bronchiectasis and highlights the significance of etiology in determining treatment approaches. Both non-drug and drug treatments are comprehensively covered. Non-pharmacological measures include smoking cessation, physiotherapy, physical training, rehabilitation, non-invasive ventilation, thoracic surgery, and lung transplantation. Pharmacological treatments focus on the long-term use of mucolytics, bronchodilators, anti-inflammatory medications, and antibiotics. Additionally, the guideline covers the challenges and strategies for managing upper airway involvement, comorbidities, and exacerbations, as well as socio-medical aspects and disability rights. The importance of patient education and self-management is also emphasized. Finally, the guideline addresses special life stages such as transition, family planning, pregnancy and parenthood, and palliative care. The aim is to ensure comprehensive, consensus-based, and patient-centered care, taking into account individual risks and needs.

Primary Ciliary Dyskinesia in Adult Bronchiectasis: Data from the German Bronchiectasis Registry PROGNOSIS

BACKGROUND

Primary ciliary dyskinesia (PCD) is a rare genetic disorder caused by the malfunction of motile cilia and a specific etiology of adult bronchiectasis of unknown prevalence. A better understanding of the clinical phenotype of adults with PCD is needed to identify individuals for referral to diagnostic testing.

RESEARCH QUESTION

What is the frequency of PCD among adults with bronchiectasis; how do people with PCD differ from those with other etiologies; and which clinical characteristics are independently associated with PCD?

STUDY DESIGN AND METHODS

We investigated the proportion of PCD among the participants of the Prospective German Non-CF-Bronchiectasis Registry (PROGNOSIS) study; applied multiple imputation to account for missing data in 64 (FEV1), 58 (breathlessness), 26 (pulmonary exacerbations), and two patients (BMI), respectively; and identified predictive variables from baseline data using multivariate logistic regression analysis.

RESULTS

We consecutively recruited 1,000 patients from 38 centers across all levels of the German health care system. Overall, PCD was the fifth most common etiology of bronchiectasis in 87 patients (9%) after idiopathic, postinfective, COPD, and asthma. People with PCD showed a distinct clinical phenotype. In multivariate regression analysis, the chance of PCD being the etiology of bronchiectasis increased with the presence of upper airway disease (chronic rhinosinusitis and/or nasal polyps; adjusted OR [aOR], 6.3; 95% CI, 3.3-11.9; P < .001), age < 53 years (aOR, 5.3; 95% CI, 2.7-10.4; P < .001), radiologic involvement of any middle and lower lobe (aOR, 3.7; 95% CI, 1.3-10.8; P = .016), duration of bronchiectasis > 15 years (aOR, 3.6; 95% CI, 1.9-6.9; P < .001), and a history of Pseudomonas aeruginosa isolation from respiratory specimen (aOR, 2.4; 95% CI, 1.3-4.5; P = .007).

INTERPRETATION

Within our nationally representative cohort, PCD was a common etiology of bronchiectasis. We identified few easy-to-assess phenotypic features, which may promote awareness for PCD among adults with bronchiectasis.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT02574143; URL: www.

CLINICALTRIALS

gov.

The prevalence and implications of depression and anxiety in patients with bronchiectasis: a systematic review and meta-analysis

Background

Comorbidities significantly affect bronchiectasis prognosis. Depression and anxiety are frequently encountered psychological comorbidities that have the greatest impact on bronchiectasis. This systematic review aimed to identify the prevalence of depression and anxiety and describe their implications for bronchiectasis.

Methods

Three databases were searched from their inception to October 2023 for studies reporting the prevalence and/or clinical implications of depression and anxiety in patients with bronchiectasis. Two independent reviewers rated the quality of the evidence presented in the studies using the risk of bias tool for prevalence studies.

Results

Of the 50 studies identified, 17 studies with 2637 patients were included. The overall risk of bias was classified as low (10 studies) or moderate (seven studies). The pooled prevalence of depression and anxiety was 31% (95% CI 24-38%) and 34% (95% CI 28-40%), respectively. Depression was significantly higher in female compared to male patients (risk difference 10%, 95% CI 0-21%) and associated with bronchiectasis exacerbation (adjusted odds ratio 1.72, 95% CI 1.28-2.15). Depression and anxiety are closely associated with poor health-related quality of life. However, clinical outcomes including dyspnoea symptoms, severity index, computed tomography score, lung function and physical activity were not associated with depression or anxiety.

Conclusion

This study revealed a high prevalence of depression and anxiety among patients with bronchiectasis. Depression was more prevalent in females and is significantly associated with bronchiectasis exacerbation. Depression and anxiety were associated with poor health-related quality of life.

Efficacy and safety of long-term macrolide therapy for non-cystic fibrosis bronchiectasis: A systematic review and meta-analysis

BACKGROUND

Long-term macrolide therapy for non-cystic fibrosis bronchiectasis (NCFB) can play a significant role. However, such data are insufficient regarding the efficacy against severe exacerbation and adverse effects, including the emergence of macrolide-resistant pathogens and prolonged macrolide use beyond 1 year.

METHODS

Randomized controlled trials (RCTs) and prospective observational studies comparing the efficacy and safety of macrolides and placebo in adult patients with NCFB were screened on April 10, 2024. The primary outcome was severe exacerbation frequency.

RESULTS

Ten RCTs ≤1 year study durations were included. Most studies mainly included patients with a history of >2 exacerbations. Macrolides had a tendency to reduce the frequency of severe exacerbations compared with placebo (odds ratio = 0.54, 95% confidence interval (CI) = 0.25-1.18). Macrolides significantly reduced the frequency of exacerbations (rate ratio = 0.58, 95% CI = 0.48-0.69), prolonged the time to first exacerbation (rate ratio = 0.41, 95% CI = 0.30-0.55), improved the changes in SGRQ scores [mean difference (MD) = -3.99, 95% CI = -4.63-3.44] and percent predicted forced expiratory volume in 1 s (MD = -2.30, 95% CI = 0.26-4.33), and reduced sputum volume (gram) (MD = -7.44, 95% CI = -9.15-5.74). Additionally, macrolides did not increase drug-related adverse events leading to discontinuation. Qualitative SR of pathogens indicated macrolides might increase the number of macrolide-resistant oropharyngeal and sputum pathogens and the emergence of Pseudomonas aeruginosa.

CONCLUSIONS

Our results support macrolide therapy for patients with NCFB. Studies with an observation period of >1 year or those focusing on patients with/without a minimal exacerbation history are required to determine the long-term effects on patients with NCFB.

Bronchiectasis in a patient with Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy: a case report

BACKGROUND

The rare monogenic syndrome Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED) leads to multisystemic autoimmunity with possible lung involvement. Autoimmune pneumonitis is a rare manifestation, with bronchiectasis being the most frequent radiologic pattern, and may lead to fatal outcome. The Sardinian population in Italy has a high incidence of APECED, although no case of lung manifestation has been reported yet in this cohort. This is the case of a Sardinian APECED patient referred to a bronchiectasis clinic. Our aim is to raise awareness and screen these patients earlier for pulmonary involvement and to initiate multidisciplinary treatment for better outcome.

CASE PRESENTATION

A 49-year-old female native of Sardinia from consanguineous parents was diagnosed with APECED in childhood and was referred to our bronchiectasis clinic in March 2023. In addition to typical APECED features, she reported recurrent respiratory infections since childhood, chronic purulent sputum and a hospitalization for pneumonia. She came to our attention with a recent isolation of P. aeruginosa on sputum culture and diffuse cylindrical and varicoid bronchiectasis on her first CT scan. She underwent aetiologic screening for bronchiectasis with no evidence of another cause of disease. Lung treatment was optimized according to bronchiectasis guidelines, and during follow-up the patient developed methicillin-resistant Staphylococcus aureus (MRSA) infection and M. intracellulare pulmonary disease. The patient was offered P. aeruginosa eradication treatment with intravenous antibiotics and initiation of antimycobacterial therapy.

CONCLUSION

This is the first documented lung involvement case of APECED in a Sardinian patient, and the first patient reported to enter a bronchiectasis program. The patient was prescribed lung imaging late in time when bronchiectasis complications were already present. Our case report highlights the need for early pulmonary screening and multidisciplinary management in patients with APECED.

Clinical Remission Predictors in Non-Colonized Bronchiectasis and Severe Asthma with Type 2-Targeted Biologic Therapy: A Retrospective Real-Life Pilot Study

Background/Objective: Patients with severe asthma (SA) and non-cystic fibrosis bronchiectasis (BE) without microbiological colonization represent a unique and understudied population. Type 2-targeted biologic therapies have emerged as a promising treatment for these patients. However, predictive factors for achieving clinical remission remain unclear. This study aims to identify the predictive factors for achieving clinical remission in patients with severe asthma and non-colonized bronchiectasis undergoing type 2-targeted biologic therapies. Methods: A retrospective longitudinal analysis was conducted on 14 patients with severe asthma and non-cystic fibrosis bronchiectasis without microbiological colonization. Clinical remission was assessed at baseline (T0) and after 12 months (T1) of biologic therapy. Clinical remission was defined according to the Severe Asthma Network Italy (SANI) criteria, including the absence of oral corticosteroid use, no asthma-related symptoms, stable lung function, and no exacerbations. Logistic regression was performed to identify predictors of remission. ROC curves were constructed to evaluate the predictive accuracy of lung function parameters, specifically FEV1 and FVC. Results: After 12 months of biologic therapy, 28.6% of patients (n = 4) achieved clinical remission. The mean FEV1 percentage at baseline was significantly higher in the remission group (92.25 ± 15.64%) compared to the non-remission group (65.10 ± 23.36%, p = 0.034). Logistic regression analysis identified baseline FEV1 as a significant predictor of remission (OR = 1.008, p = 0.050). ROC curve analysis revealed that an FEV1 cutoff of 72.5% had a sensitivity of 100% and a specificity of 70% (AUC = 0.900, p = 0.024) for predicting clinical remission. Conclusions: FEV1 is a crucial predictor of clinical remission in patients with severe asthma and non-colonized bronchiectasis treated with type 2-targeted biologic therapies. An FEV1 threshold of 72.5% can guide clinicians in identifying patients most likely to achieve remission. These findings underline the importance of preserving lung function to optimize therapeutic outcomes in this complex population.

Discovery and analysis of the relationship between organic components in exhaled breath and bronchiectasis

The prevalence of patients with bronchiectasis (BE) has been rising in recent years, which increases the substantial burden on the family and society. Exploring a convenient, effective, and low-cost screening tool for the diagnosis of BE is urgent. We expect to identify the accuracy (ACC) of breath biomarkers (BBs) for the diagnosis of BE through breathomics testing and explore the association between BBs and clinical features of BE. Exhaled breath samples were collected and detected by high-pressure photon ionization time-of-flight mass spectrometry in a cross-sectional study. Exhaled breath samples were from 215 patients with BE and 295 control individuals. The potential BBs were selected via the machine learning (ML) method. The overall performance was assessed for the BBs-based BE detection model. The significant BBs between different subgroups such as the severity of BE, acute or stable stage, combined with hemoptysis or not, with or without nontuberculous mycobacterium (NTM),P. aeruginosa(P.a) isolation or not, and the BBs related to the number of involved lung lobes and lung function were discovered and analyzed. The top ten BBs based ML model achieved an area under the curve of 0.940, sensitivity of 90.7%, specificity of 85%, and ACC of 87.4% in BE diagnosis. Except for the top ten BBs, other BBs were found also related to the severity, acute/stable status, hemoptysis or not, NTM infection,P.aisolation, the number of involved lobes, and three lung functional parameters in BE patients. BBs-based BE detection model showed good ACC for diagnosis. BBs have a close relationship with the clinical features of BE. The breath test method may provide a new strategy for BE screening and personalized management.

Long-Term High-Flow Nasal Therapy in Patients with Bronchiectasis of Different Severity: A Retrospective Cohort Study

Background/Objectives: High-flow nasal therapy (HFNT) has been shown to reduce exacerbations of COPD and some evidence displays benefits in non-cystic fibrosis bronchiectasis (NCFB) patients. The present study aimed to compare the effectiveness of 12 months of home HFNT on the annual exacerbation rate between mild/moderate and severe NCFB patients, classified by the bronchiectasis severity index (BSI). Secondary outcomes were the evaluation of the dyspnea, pulmonary function, and sputum cultures in both groups. Methods: The study population included NCFB adult patients, with at least one severe exacerbation in the previous year on optimized therapy. NCFB exacerbations, dyspnea (mMRC score), pulmonary function test, and sputum cultures were assessed at baseline and after 12 months of HFNT. Results: A total of 86 NCFB patients were enrolled: 36 in the mild/moderate (BSI < 9) and 50 in the severe (BSI ≥ 9) group. A significant improvement in the annual exacerbation rate was found in both BSI ≥ 9 (p < 0.0001) and BSI < 9 cohorts (p < 0.0001), with a between-group difference of -1 (95% CI: -2 to 0) exacerbations per year (p = 0.0209). The change in the annual exacerbation rate was significantly correlated with BSI (ρ = -0.26, p = 0.0151) and with HFNT daily use (ρ = -0.22, p = 0.0460). The mMRC score significantly improved by -2 points (95% CI: -2 to -1) after treatment in both groups (p < 0.0001). The percentage of patients with P. aeruginosa colonization decreased from 34.9% to 27.9%. Conclusions: Long-term HFNT reduces the annual exacerbation rate in NCFB patients and its effectiveness increases alongside disease severity and daily use of HFNT.

Epidemiology of bronchiectasis

Bronchiectasis is a chronic respiratory disease characterised by permanent enlargement of the airways associated with cough, sputum production and a history of pulmonary exacerbations. In the past few years, incidence and prevalence of bronchiectasis have increased worldwide, possibly due to advances in imaging techniques and disease awareness, leading to increased socioeconomic burden and healthcare costs. Consistently, a mortality increase in bronchiectasis patient cohorts has been demonstrated in certain areas of the globe, with mortality rates of 16-24.8% over 4-5 years of follow-up. However, heterogeneity in epidemiological data is consistent, as reported prevalence in the general population ranges from 52.3 to more than 1000 per 100 000. Methodological flaws in the designs of available studies are likely to underestimate the proportion of people suffering from this condition worldwide and comparisons between different areas of the globe might be unreliable due to different assessment methods or local implementation of the same method in different contexts. Differences in disease severity associated with diverse geographical distribution of aetiologies, comorbidities and microbiology might explain an additional quota of heterogeneity. Finally, limited access to care in certain geographical areas is associated with both underestimation of the disease and increased severity and mortality. The aim of this review is to provide a snapshot of available real-world epidemiological data describing incidence and prevalence of bronchiectasis in the general population. Furthermore, data on mortality, healthcare burden and high-risk populations are provided. Finally, an analysis of the geographical distribution of determinants contributing to differences in bronchiectasis epidemiology is offered.

Pulmonary vascular resistance predicts the mortality in patients with bronchiectasis-associated pulmonary hypertension

OBJECTIVE

Pulmonary hypertension is a severe complication of bronchiectasis, characterized by elevated pulmonary vascular resistance (PVR) and subsequent right heart failure. The association between PVR and mortality in bronchiectasis-associated pulmonary hypertension has not been investigated previously.

METHODS

In the present study, a retrospective analysis was conducted on 139 consecutive patients diagnosed with bronchiectasis-associated pulmonary hypertension based on right heart catheterization, enrolled between January 2010 and June 2023. Baseline clinical characteristics and hemodynamic assessment were analyzed. The survival time for each patient was calculated in months from the date of diagnosis until the date of death or, if the patient was still alive, until their last visit.

RESULTS

Patients with bronchiectasis-associated pulmonary hypertension exhibited estimated survival rates of 89.5, 70, and 52.9 at 1-year, 3-year, and 5-year intervals respectively, with a median survival time of 67 months. Multivariable Cox regression analysis revealed that increased age [(adjusted hazard ratio per year 1.042, 95% confidence interval (CI) 1.008-1.076, P  = 0.015] and elevated PVR (adjusted HR per 1 Wood Units 1.115, 95% CI 1.015-1.224, P  = 0.023) were associated with an increased risk of all-cause mortality. In contrast, higher BMI was associated with a decreased risk of all-cause death (adjusted hazard ratio per 1 kg/m 2 0.915, 95% CI 0.856-0.979, P  = 0.009). Receiver-operating characteristic analyses identified a cutoff value for PVR at 4 Wood Units as predictive for all-cause death within 3 years [area under the curve (AUC) = 0.624; specificity= 87.5%; sensitivity= 35.8%; P  < 0.05]. Patients with a PVR greater than 4 Wood Units had a significantly higher risk of all-cause death compared with those with 4 Wood Units or less (adjusted hazard ratio 2.392; 95% CI 1.316-4.349; P  = 0.019). Notably, there were no significant differences in age, sex, BMI, WHO functional class, 6-min walk distance, and NT-proBNP levels at baseline between patients categorized as having 4 Wood Units or less or greater than 4 Wood Units for PVR.

CONCLUSION

Based on these data, PVR could serve as a discriminative marker for distinguishing between nonsevere pulmonary hypertension (PVR ≤ 4 Wood Units) and severe pulmonary hypertension (PVR > 4 Wood Units). The utilization of a PVR cutoff value of 4.0 Wood Units provides enhanced prognostic capabilities for predicting mortality.

Prevalence of bronchiectasis in adults: a meta-analysis

BACKGROUND

Bronchiectasis, once considered an orphan disease, is receiving attention globally owing to its increasing prevalence, healthcare burden, and associated morbidity. However, the prevalence of bronchiectasis is unclear. This meta-analysis estimates the prevalence of bronchiectasis in adults, providing a valuable reference for future research.

METHODS

PubMed, Embase, Cochrane Library, and Web of Science databases were searched from inception to May 31, 2024 for studies reporting the prevalence of bronchiectasis. Study selection, data extraction, and overall analysis of risk of the retrieved studies were conducted independently by two authors. The tool for assessing the risk of bias in prevalence studies was used to evaluate overall risk. Stata software (version 15.1) was used to performed the meta-analysis. Subgroup and sensitivity analyses were conducted to identify the source of heterogeneity. Funnel plots combined with Egger's test were used to detect publication bias.

RESULTS

The pooled prevalence of bronchiectasis in adults from 15 studies covering 437,851,478 individuals was 680 per 100,000 (95% CI: 634-727 per 100,000). Subgroup analysis showed that the prevalence of bronchiectasis in the United States, Korea, and China was 478 per 100,000 (95% CI: 367-588 per 100,000), 886 per 100,000 (95% CI: 778-993 per 100,000), and 759 per 100,000 (95% CI: 35-2399 per 100,000), respectively; 467 per 100,000 (95% CI: 416-518 per 100,000) in males and 535 per 100,000 (95% CI: 477-592 per 100,000) in females; 3958 per 100,000 (95% CI: 117-12637 per 100,000), 4677 per 100,000 (95% CI: 427-8928 per 100,000), and 3630 per 100,000 (95% CI: 158-7103 per 100,000) among never-smokers, ever-smokers, and current smokers, respectively; 430 per 100,000 (95% CI: 411-450 per 100,000), 380 per 100,000 (95% CI: 374-386 per 100,000), and 351 per 100,000 (95% CI: 342-360 per 100,000) among individuals with body mass index<18.5, 18.5-24.9, and ≥ 25, respectively. Sixteen comorbidities were evaluated in patients with bronchiectasis, revealing a high rate.

CONCLUSION

Bronchiectasis is not a rare disease and requires more attention from scientific researchers.

TRIAL REGISTRATION

The protocol for this review was registered with PROSPERO: CRD42023409216. Registered 26 June 2023.

Safety profile of drugs used in non-cystic fibrosis bronchiectasis: a narrative review

Non-cystic fibrosis bronchiectasis is a long-term lung disease characterised by abnormal dilatation of the bronchi, with patients experiencing chronic productive cough and recurrent exacerbations. Currently, there are no licensed drugs for use in bronchiectasis while clinical trials have been conducted to either test new drugs or repurpose existing ones. These drugs target the underlying pathophysiology of bronchiectasis which is known to include infection, inflammation, mucus hypersecretion and retention. Most of the drugs used in daily clinical practice for bronchiectasis are off-label with no randomised trials exploring their safety. This review aims at exploring the safety profile of drugs frequently used in clinical practice to manage bronchiectasis, including antibiotics (e.g. macrolides, aminoglycosides, polymyxins, fluoroquinolones, aztreonam), mucoactive therapy (e.g. hypertonic saline, mannitol, DNase and carbocisteine), anti-inflammatory therapy (inhaled corticosteroids) and drugs currently in development for use in bronchiectasis (e.g. brensocatib, benralizumab and itepekimab).

The impact of cardiovascular events in bronchiectasis: a systematic review and meta-analysis

Background

Bronchiectasis is a chronic respiratory condition characterised by airway and systemic inflammation with prevalence increasing with age. Given the median age of the patients, it is common to observe the presence of comorbidities, particularly cardiovascular diseases, which have been linked to adverse clinical outcomes. To investigate the pooled estimates of the association between bronchiectasis and coronary heart disease or stroke within this population, we conducted a systematic review and meta-analysis of the available scientific evidence.

Methods

Three investigators independently performed the search on PubMed and other sources and included studies published up to October 2023 according to predefined criteria. Relative measures of association between bronchiectasis and cardiovascular events were pooled and meta-analysed using a fixed-effects model. Studies were evaluated using the Newcastle-Ottawa Scale for assessing the quality of non-randomised studies in meta-analyses.

Results

A final pool of nine studies was included in the systematic review, with a total of 22 239 patients. Meta-analysis of three high-quality cohort studies showed a pooled hazard ratio of 1.42 (95% CI 1.30-1.57) for coronary heart disease and 1.71 (95% CI 1.55-1.89) for cerebrovascular stroke.

Conclusions

The increased cardiovascular risk among people with bronchiectasis underscores the critical need to raise awareness of this association and to develop preventive strategies accordingly. Further translational studies are imperative to gain a deeper understanding of the complex interplay between inflammation, the immune system and endothelial dysfunction in this patient group.

Evidence-based management guidelines for noncystic fibrosis bronchiectasis in children and adolescents

Noncystic fibrosis bronchiectasis is a chronic respiratory disease that carries high socioeconomic and medical burdens and is caused by diverse respiratory illnesses. To improve clinical outcomes, early recognition, active treatment of exacerbations, and prevention of further exacerbations are essential. However, evidence for the treatment and prevention of acute exacerbation of noncystic fibrosis bronchiectasis, especially in children, is lacking. Therefore, the evidence- and consensus-based guidelines for medical and nonmedical treatment strategies for noncystic fibrosis bronchiectasis in children and adolescents were developed by the Korean Academy of Pediatric Allergy and Respiratory Disease using the methods recommended by the Grading of Recommendations Assessment, Development, and Evaluation working group with evidence published through July 2, 2020. This guideline encompasses evidence-based treatment recommendations as well as expert opinions, addressing crucial aspects of the treatment and management of non-cystic fibrosis bronchiectasis in children. This includes considerations for antibiotics and airway clearance strategies, particularly in areas where evidence may be limited. Large, well-designed, and controlled studies are required to accumulate further evidence of management strategies for noncystic fibrosis bronchiectasis in children and adolescents.

Eosinophilic Bronchiectasis: Prevalence, Severity, and Associated Features-A Cohort Study

Background: Bronchiectasis (BE) has been traditionally associated with neutrophilic inflammation, but eosinophilic bronchiectasis (EB) has recently emerged. Data about prevalence, clinical features, and disease severity are lacking. This study aimed to assess the EB prevalence, compare EB with non-EB, evaluate the Type-2 (T2) high endotype in BE (T2-high EB) versus non-T2-high EB, and identify EB predictors. Methods: We conducted a prospective study involving 153 BE patients. The data collected included clinical, radiological, and microbiological findings. BE severity was assessed using the bronchiectasis severity index (BSI), FACED and E-FACED scores, and the bronchiectasis etiology and comorbidity index (BACI). EB was defined as a blood eosinophil count (BEC) ≥ 300 cells/μL, and T2-high EB as BEC ≥ 300 cells/μL with fractional exhaled nitric oxide (FeNO) ≥ 25 ppb. Results: Prevalence was 27% for EB and 20% for T2-high EB. EB patients exhibited poorer lung function and more severe radiologic features, with significantly higher severity scores [BSI, FACED, E-FACED, BACI (p < 0.05)], and a higher median exacerbation rate [4 (2-5) in EB vs. 2 (1-4) in non-EB, p = 0.0002], compared with non-EB patients. T2-high EB patients showed higher severity scores [BSI, FACED, E-FACED (p < 0.05)], as well as worse lung function parameters [FEV1%, FVC%, FEF 25-75% (p < 0.05)] compared with non-T2-high EB patients. In our study, patients with EB exhibited notably worsened lung function and higher BE severity scores compared with their non-EB counterparts, with exacerbations playing a major role in these differences. We found statistically significant positive correlations between BEC and disease severity scores, such as BSI, FACED, and mMRC, as well as an inverse relationship with pulmonary function. The likelihood of EB being present was significantly higher in association with mMRC ≥ 1 (OR = 2.53; 95% CI, 1.26-5.64), exacerbations/year ≥ 1 (OR = 1.27; 95% CI, 1.0-1.63), and chronic PA colonization (OR = 3.9; 95% CI, 1.08-15.8). Conclusions: EB is a distinct endotype. Dyspnea, exacerbations, and PA colonization may be predictive of EB, emphasizing the importance of early detection for improved outcomes. BEC could serve as a useful biomarker of disease severity to consider when diagnosing EB.

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

RATIONALE

The inflammasome is a key regulatory complex of the inflammatory response leading to interleukin-1β (IL-1β) release and activation. IL-1β amplifies inflammatory responses and induces mucus secretion and hyperconcentration in other diseases. The role of IL-1β in bronchiectasis has not been investigated.

OBJECTIVES

To characterise the role of airway IL-1β 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-1β 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-1β 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 the effect of IL-1β on cilia function.

RESULTS

Patients with high sputum IL-1β had more severe disease, increased caspase-1 activity and an increased T-helper type 1, T-helper type 2 and neutrophil inflammatory response compared with patients with low IL-1β. The active-dominant form of IL-1β was associated with increased disease severity. High IL-1β was related to higher relative abundance of Proteobacteria in the microbiome and increased mucus solid content and viscoelastic properties. Chronic IL-1β 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-1β, suggesting pulmonary inflammasome activation is linked with more severe disease, airway infection, mucus dehydration and epithelial dysfunction.

[Bronchiectasis not due to cystic fibrosis]

Bronchiectasis is a clinical-radiological condition composed of irreversible bronchial dilation due to inflammation and infection of the airways, which causes respiratory symptoms, usually productive cough and infectious exacerbations. Bronchiectasis can have multiple causes, both pulmonary and extrapulmonary, and its clinical presentation is very heterogenous. Its prevalence is unknown, although up to 35-50% of severe COPD and 25% of severe asthma present them, so their underdiagnosis is evident. Chronic bacterial bronchial infection is common, and Pseudomonas aeruginosa is the pathogen that has been found to imply a worse prognosis. Treatment of bronchiectasis has three fundamental characteristics: it must be multidisciplinary (involvement of several specialties), pyramidal (from primary care to the most specialized units) and multidimensional (management of all aspects that make up the disease).

Phenotypical characteristics of nontuberculous mycobacterial infection in patients with bronchiectasis

BACKGROUND

The global mortality and morbidity rates of bronchiectasis patients due to nontuberculous mycobacteria (NTM) pulmonary infection are on a concerning upward trend. The aims of this study to identify the phenotype of NTM-positive individuals with bronchiectasis.

METHODS

A retrospective single-center observational study was conducted in adult patients with bronchiectasis who underwent bronchoscopy in 2007-2020. Clinical, laboratory, pulmonary function, and radiological data were compared between patients with a positive or negative NTM culture.

RESULTS

Compared to the NTM-negative group (n=677), the NTM-positive group (n=94) was characterized (P ≤0.05 for all) by older age, greater proportion of females, and higher rates of gastroesophageal reflux disease and muco-active medication use; lower body mass index, serum albumin level, and lymphocyte and eosinophil counts; lower values of forced expiratory volume in one second, forced vital capacity, and their ratio, and lower diffusing lung capacity for carbon monoxide; higher rates of bronchiectasis in both lungs and upper lobes and higher number of involved lobes; and more exacerbations in the year prior bronchoscopy. On multivariate analysis, older age (OR 1.05, 95% CI 1.02-1.07, P=0.001), lower body mass index (OR 1.16, 95% CI 1.16-1.07, P <0.001), and increased number of involved lobes (OR 1.26, 95% CI 1.01-1.44, P=0.04) were associated with NTM infection.

CONCLUSIONS

Patients with bronchiectasis and NTM pulmonary infection are more likely to be older and female with more severe clinical, laboratory, pulmonary function, and radiological parameters than those without NTM infection. This phenotype can be used for screening patients with suspected NTM disease.

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

Rationale: COPD and bronchiectasis are commonly reported together. Studies report varying impacts of co-diagnosis on outcomes, which may be related to different definitions of disease used across studies. Objectives: To investigate the prevalence of chronic obstructive pulmonary disease (COPD) associated with bronchiectasis and its relationship with clinical outcomes. We further investigated the impact of implementing the standardized ROSE criteria (radiological bronchiectasis [R], obstruction [FEV1/FVC ratio <0.7; O], symptoms [S], and exposure [⩾10 pack-years of smoking; E]), an objective definition of the association of bronchiectasis with COPD. Methods: Analysis of the EMBARC (European Bronchiectasis Registry), a prospective observational study of patients with computed tomography-confirmed bronchiectasis from 28 countries. The ROSE criteria were used to objectively define the association of bronchiectasis with COPD. Key outcomes during a maximum of 5 years of follow-up were exacerbations, hospitalization, and mortality. Measurements and Main Results: A total of 16,730 patients with bronchiectasis were included; 4,336 had a clinician-assigned codiagnosis of COPD, and these patients had more exacerbations, worse quality of life, and higher severity scores. We observed marked overdiagnosis of COPD: 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 of smoking. Therefore, 2,157 patients (55.4%) met the ROSE criteria for COPD. Compared with patients without COPD, patients who met the ROSE criteria had increased risks of exacerbations and exacerbations resulting in hospitalization during follow-up (incidence rate ratio, 1.25; 95% confidence interval, 1.15-1.35; vs. incidence rate ratio, 1.69; 95% confidence interval, 1.51-1.90, respectively). Conclusions: The label of COPD is often applied to patients with bronchiectasis who do not have objective evidence of airflow obstruction or a smoking history. Patients with a clinical label of COPD have worse clinical outcomes.

Exacerbations of bronchiectasis

Bronchiectasis presents a significant challenge due to its rising prevalence, associated economic burden and clinical heterogeneity. This review synthesises contemporary understanding and literature of bronchiectasis exacerbations, addressing the transition from stable state to exacerbations, underlining the importance of early and precise recognition, rigorous severity assessment, prompt treatment, and prevention measures, as well as emphasising the need for strategies to assess and improve early and long-term patient outcomes. The review highlights the interplay between stable state phases and exacerbations in bronchiectasis, introducing the concept of "exogenous and endogenous changes in airways homeostasis" and the "adapted island model" with a particular focus on "frequent exacerbators", a group of patients associated with specific clinical characteristics and worse outcomes. The pathophysiology of exacerbations is explored through the lens of microbial and nonmicrobial triggers and the presence and the activity of comorbidities, elaborating on the impact of both exogenous insults, such as infections and pollution, and endogenous factors such as inflammatory endotypes. Finally, the review proposes a multidisciplinary approach to care, integrating advancements in precision medicine and biomarker research, paving the way for tailored treatments that challenge the traditional antibiotic paradigm.

Structural Lung Disease and Clinical Phenotype in Bronchiectasis Patients: The EMBARC CT Study

Rationale: Chest computed tomography (CT) scans are essential to diagnose and monitor bronchiectasis (BE). To date, few quantitative data are available about the nature and extent of structural lung abnormalities (SLAs) on CT scans of patients with BE. Objectives: To investigate SLAs on CT scans of patients with BE and the relationship of SLAs to clinical features using the EMBARC (European Multicenter Bronchiectasis Audit and Research Collaboration) registry. Methods: CT scans from patients with BE included in the EMBARC registry were analyzed using the validated Bronchiectasis Scoring Technique for CT (BEST-CT). The subscores of this instrument are expressed as percentages of total lung volume. The items scored are atelectasis/consolidation, BE with and without mucus plugging (MP), airway wall thickening, MP, ground-glass opacities, bullae, airways, and parenchyma. Four composite scores were calculated: total BE (i.e., BE with and without MP), total MP (i.e., BE with MP plus MP alone), total inflammatory changes (i.e., atelectasis/consolidation plus total MP plus ground-glass opacities), and total disease (i.e., all items but airways and parenchyma). Measurements and Main Results: CT scans of 524 patients with BE were analyzed. Mean subscores were 4.6 (range, 2.3-7.7) for total BE, 4.2 (1.2-8.1) for total MP, 8.3 (3.5-16.7) for total inflammatory changes, and 14.9 (9.1-25.9) for total disease. BE associated with primary ciliary dyskinesia was associated with more SLAs, whereas chronic obstructive pulmonary disease was associated with fewer SLAs. Lower FEV1, longer disease duration, Pseudomonas aeruginosa and nontuberculous mycobacterial infections, and severe exacerbations were all independently associated with worse SLAs. Conclusions: The type and extent of SLAs in patients with BE are highly heterogeneous. Strong relationships between radiological disease and clinical features suggest that CT analysis may be a useful tool for clinical phenotyping.

Pathophysiology and genomics of bronchiectasis

Bronchiectasis is a complex and heterogeneous inflammatory chronic respiratory disease with an unknown cause in around 30-40% of patients. The presence of airway infection together with chronic inflammation, airway mucociliary dysfunction and lung damage are key components of the vicious vortex model that better describes its pathophysiology. Although bronchiectasis research has significantly increased over the past years and different endotypes have been identified, there are still major gaps in the understanding of the pathophysiology. Genomic approaches may help to identify new endotypes, as has been shown in other chronic airway diseases, such as COPD.Different studies have started to work in this direction, and significant contributions to the understanding of the microbiome and proteome diversity have been made in bronchiectasis in recent years. However, the systematic application of omics approaches to identify new molecular insights into the pathophysiology of bronchiectasis (endotypes) is still limited compared with other respiratory diseases.Given the complexity and diversity of these technologies, this review describes the key components of the pathophysiology of bronchiectasis and how genomics can be applied to increase our knowledge, including the study of new techniques such as proteomics, metabolomics and epigenomics. Furthermore, we propose that the novel concept of trained innate immunity, which is driven by microbiome exposures leading to epigenetic modifications, can complement our current understanding of the vicious vortex. Finally, we discuss the challenges, opportunities and implications of genomics application in clinical practice for better patient stratification into new therapies.

Endotypes of Exacerbation in Bronchiectasis: An Observational Cohort Study

Rationale: Bronchiectasis is characterized by acute exacerbations, but the biological mechanisms underlying these events are poorly characterized. Objectives: To investigate the inflammatory and microbial characteristics of exacerbations of bronchiectasis. Methods: A total of 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 before 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 chromatography-tandem mass spectrometry and measurement of sputum cytokines and neutrophil elastase activity. 16 s rRNA sequencing was used to characterize the microbiome. Measurements and Main Results: Bronchiectasis exacerbations showed profound molecular heterogeneity. At least one bacterium was identified in 103 samples (86%), and a high bacterial load (total bacterial load > 107 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 testing 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-1β, and CXCL8. These markers were particularly associated with bacterial and bacterial plus 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 four subtypes of exacerbation. Conclusions: Bronchiectasis exacerbations are heterogeneous events with contributions from bacteria, viruses, and inflammatory dysregulation.

Longitudinal Evaluation of Bronchial Changes in Cystic Fibrosis Patients Undergoing Elexacaftor/Tezacaftor/Ivacaftor Therapy Using Lung MRI With Ultrashort Echo-Times

BACKGROUND

Lung magnetic resonance imaging (MRI) with ultrashort echo-times (UTE-MRI) allows high-resolution and radiation-free imaging of the lung structure in cystic fibrosis (CF). In addition, the combination of elexacaftor/tezacaftor/ivacaftor (ETI) has improved CF clinical outcomes such as need for hospitalization. However, the effect on structural disease still needs longitudinal evaluation at high resolution.

PURPOSE

To analyze the effects of ETI on lung structural alterations using UTE-MRI, with a focus on bronchiectasis reversibility.

STUDY TYPE

Retrospective.

POPULATION

Fifty CF patients (mean age 24.3 ± 9.2; 23 males).

FIELD STRENGTH/SEQUENCE

1.5 T, UTE-MRI.

ASSESSMENT

All subjects completed both UTE-MRI and pulmonary function tests (PFTs) during two annual visits (M0 and M12), and 30 of them completed a CT scan. They initiated ETI treatment after M0 within a maximum of 3 months from the annual examinations. Three observers scored a clinical MRI Bhalla score on UTE-MRI. Bronchiectasis reversibility was defined as a reduction in both outer and inner bronchial dimensions. Correlations were searched between the Bhalla score and PFT such as the forced expiratory volume in 1 second percentage predicted (FEV1%p).

STATISTICAL TESTS

Comparison was assessed using the paired t-test, correlation using the Spearman correlation test with a significance level of 0.05. Concordance and reproducibility were assessed using intraclass correlation coefficient (ICC).

RESULTS

There was a significant improvement in MRI Bhalla score after ETI treatment. UTE-MRI demonstrated bronchiectasis reversibility in a subgroup of 18 out of 50 CF patients (36%). These patients with bronchiectasis reversibility were significantly younger, with lower severity of wall thickening but no difference in mucus plugging extent (P = 0.39) was found. The reproducibility of UTE-MRI evaluations was excellent (ICC ≥ 0.95), was concordant with CT scan (N = 30; ICC ≥ 0.90) and significantly correlated to FEV1% at PFT at M0 (N = 50; r = 0.71) and M12 (N = 50; r = 0.72).

DATA CONCLUSION

UTE-MRI is a reproducible tool for the longitudinal follow-up of CF patients, allowing to quantify the response to ETI and demonstrating the reversibility of some structural alterations such as bronchiectasis in a substantial fraction of this study population.

LEVEL OF EVIDENCE

4 TECHNICAL EFFICACY: Stage 2.

Infection and the microbiome in bronchiectasis

Bronchiectasis is marked by bronchial dilatation, recurrent infections and significant morbidity, underpinned by a complex interplay between microbial dysbiosis and immune dysregulation. The identification of distinct endophenotypes have refined our understanding of its pathogenesis, including its heterogeneous disease mechanisms that influence treatment and prognosis responses. Next-generation sequencing (NGS) has revolutionised the way we view airway microbiology, allowing insights into the "unculturable". Understanding the bronchiectasis microbiome through targeted amplicon sequencing and/or shotgun metagenomics has provided key information on the interplay of the microbiome and host immunity, a central feature of disease progression. The rapid increase in translational and clinical studies in bronchiectasis now provides scope for the application of precision medicine and a better understanding of the efficacy of interventions aimed at restoring microbial balance and/or modulating immune responses. Holistic integration of these insights is driving an evolving paradigm shift in our understanding of bronchiectasis, which includes the critical role of the microbiome and its unique interplay with clinical, inflammatory, immunological and metabolic factors. Here, we review the current state of infection and the microbiome in bronchiectasis and provide views on the future directions in this field.

Association between bronchiectasis exacerbations and longitudinal changes in FEV1 in patients from the US bronchiectasis and NTM research registry

BACKGROUND

This study aimed to evaluate the association between the number of non-cystic fibrosis bronchiectasis (bronchiectasis) exacerbations during baseline and follow-up (objective 1) and to identify longitudinal changes in FEV1 associated with exacerbation frequency (objective 2).

METHODS

This was a retrospective cohort study of adult patients enrolled in the US Bronchiectasis and Nontuberculous Mycobacteria Research Registry September 2008 to March 2020. Objective 1 outcome was association between exacerbations during baseline (24 months) and 0-to-24 month and 24-to-48 month follow-up windows. Objective 2 outcomes were change in FEV1 and FEV1 % predicted over 24 months stratified by baseline exacerbation frequency.

RESULTS

Objective 1 cohort (N = 520) baseline frequency of any exacerbations was 59.2%. Overall, 71.4% and 75.0% of patients with ≥1 baseline exacerbations had ≥1 exacerbations during the 0-to-24 and 24-to-48 month follow-ups. Having ≥1 exacerbation during baseline was significantly associated with ≥1 exacerbation during the 0-to-24 month (P = 0.0085) and 24-to-48 month follow-ups (P=<0.0001). Objective 2 cohort (N = 431) baseline FEV1 was significantly lower in patients who had more exacerbations; however, decline in FEV1 from baseline was not significantly different between patients with 0, 1, and ≥2 exacerbations. In patients with more baseline exacerbations, FEV1 % predicted was significantly lower at baseline (P < 0.0001) and at 12 (P = 0.0002) and 24 month follow-ups (P < 0.0001).

CONCLUSIONS

Patients with frequent bronchiectasis exacerbations may be more likely than those with less frequent exacerbations to experience disease progression based on future exacerbation frequency and lower FEV1 at baseline, although FEV1 decline may not differ by baseline exacerbation frequency.

Biomarkers in bronchiectasis

Bronchiectasis is a heterogeneous disease with multiple aetiologies and diverse clinical features. There is a general consensus that optimal treatment requires precision medicine approaches focused on specific treatable disease characteristics, known as treatable traits. Identifying subtypes of conditions with distinct underlying biology (endotypes) depends on the identification of biomarkers that are associated with disease features, prognosis or treatment response and which can be applied in clinical practice. Bronchiectasis is a disease characterised by inflammation, infection, structural lung damage and impaired mucociliary clearance. Increasingly there are available methods to measure each of these components of the disease, revealing heterogeneous inflammatory profiles, microbiota, radiology and mucus and epithelial biology in patients with bronchiectasis. Using emerging biomarkers and omics technologies to guide treatment in bronchiectasis is a promising field of research. Here we review the most recent data on biomarkers in bronchiectasis.

Bronchiectasis

Non-cystic fibrosis bronchiectasis, a condition that remains relatively underrecognized, has garnered increasing research focus in recent years. This scientific interest has catalyzed advancements in diagnostic methodologies, enabling comprehensive clinical and molecular profiling. Such progress facilitates the development of personalized treatment strategies, marking a significant step toward precision medicine for these patients. Bronchiectasis poses significant diagnostic challenges in both clinical settings and research studies. While computed tomography (CT) remains the gold standard for diagnosis, novel alternatives are emerging. These include artificial intelligence-powered algorithms, ultra-low dose chest CT, and magnetic resonance imaging (MRI) techniques, all of which are becoming recognized as feasible diagnostic tools. The precision medicine paradigm calls for refined characterization of bronchiectasis patients by analyzing their inflammatory and molecular profiles. Research into the underlying mechanisms of inflammation and the evaluation of biomarkers such as neutrophil elastase, mucins, and antimicrobial peptides have led to the identification of distinct patient endotypes. These endotypes present variable clinical outcomes, necessitating tailored therapeutic interventions. Among these, eosinophilic bronchiectasis is notable for its prevalence and specific prognostic factors, calling for careful consideration of treatable traits. A deeper understanding of the microbiome's influence on the pathogenesis and progression of bronchiectasis has inspired a holistic approach, which considers the multibiome as an interconnected microbial network rather than treating pathogens as solitary entities. Interactome analysis therefore becomes a vital tool for pinpointing alterations during both stable phases and exacerbations. This array of innovative approaches has revolutionized the personalization of treatments, incorporating therapies such as inhaled mannitol or ARINA-1, brensocatib for anti-inflammatory purposes, and inhaled corticosteroids specifically for patients with eosinophilic bronchiectasis.

Baseline neutrophil-to-lymphocyte ratio as a predictor of response to hospitalized bronchiectasis exacerbation risks

Background

Bronchiectasis is a disease with predominantly neutrophilic inflammation. As a readily available biomarker, there is little evidence to support the use of blood neutrophil-to-lymphocyte ratio (NLR) to predict bronchiectasis exacerbation severe enough to warrant hospitalization.

Methods

A registry-based retrospective cohort study was conducted at a in Hong Kong. Chinese patients with non-cystic fibrosis (CF) bronchiectasis were retrospectively reviewed and subsequently followed up to investigate the association of NLR and the need for hospitalization for bronchiectasis exacerbation. Data on the NLR for patients in a clinically stable state in 2018 were collected and patients followed up from 1 January 2019 to 31 December 2022. The primary outcome was the need for hospitalization due to bronchiectasis exacerbation over the next 4 years.

Results

We reviewed 473 Chinese patients with non-CF bronchiectasis, of whom 94 required hospitalization for bronchiectasis exacerbation during the 4-year follow-up period. Multi-variable logistic regression adjusted for E-FACED score (Exacerbation, Forced expiratory volume in 1 s (FEV1), Age, Chronic colonization, Extension, and Dyspnea score), gender, age, smoking status, and presence of co-existing chronic obstructive pulmonary disease (COPD) was conducted to compare patients with highest and lowest quartile NLR. Results revealed that those with NLR at the highest quartile were at increased risk of hospitalization for bronchiectasis exacerbation with an adjusted odds ratio (aOR) of 2.02 (95% confidence interval = 1.00-4.12, p = 0.05).

Conclusion

Blood NLR may serve as a marker to predict the need for hospitalization due to bronchiectasis exacerbation.