Research on the Mechanism Affecting Progression of Bronchiectasis

Study Overview
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Brief Summary
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Bronchiectasis is a chronic inflammatory respiratory disease defined as the irreversible dilatation of one or more bronchi and is associated with chronic and frequently purulent expectoration, multiple exacerbations and progressive dyspnea. Bronchiectasis has a large heterogeneity. Different patients with bronchiectasis may have different etiology, clinical manifestations, and imaging features. Previous studies showed that there are significant relationship between the airway microbiome and the severity of the disease. For example, patient with airway Pseudomonas aeruginosa colonization has heavier symptoms, heavier severity, poorer quality of life, more acute exacerbations, and worse prognosis. A large number of studies have reported that long-term treatment of low-dose macrolides such as azithromycin or clarithromycin has anti-inflammatory and immunomodulatory effects, which can improve the clinical symptoms and disease progression of various chronic airway diseases, such as diffuse panbronchiolitis, chronic obstructive pulmonary disease, bronchiectasis. Both the 2017 European Respiratory Society guidelines and the 2019 British Thoracic Society Guideline recommend macrolide drugs for the treatment of chronic Pseudomonas aeruginosa colonization bronchiectasis or frequent acute exacerbations bronchiectasis, but the specific mechanism is unknown.This study is based on omics methods (Microbiology and Metabolomics) to deeply explore the composition of airway and gut microbiota in patients with bronchiectasis, the factors affecting the colonization of Pseudomonas aeruginosa and the mechanism of macrolides in the treatment of bronchiectasis. This study collected clinical data of bronchiectasis (including demographic information, clinical characteristics, lung function, and lung imaging), spontaneous sputum, stool, and peripheral blood, and followed up these patients for 12 months. Microbiology，metabolomics and cytokine in sputum and stool are tested, and cytokines, inflammatory mediators and metabolites in peripheral blood are tested. Through the above methods,investigators further understand the mechanism affecting progression of bronchiectasis and some factors that lead to the colonization of Pseudomonas aeruginosa, as well as mechanisms of macrolides in the treatment of bronchiectasis.

Detailed Description
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Clinical information: Demographic information,blood test results,lung function,severity of disease was evaluated using the E-FACED and the Bronchiectasis Severity Index (BSI).The severity of dyspnea was assessed using the Medical Research Council (MRC) grade, and lung radiological severity was assessed using the modified Reiff score and Bhalla score. Sputum collection: We collect sputum samples from patients with bronchiectasis. We divided into two parts from each sputum sample, one part was immediately stored -80℃ for microbiota sequencing, and the other part was diluted in PBS and centrifuge at 12,000g for 5 min, and supernatant stored at -80℃ for measurement of inflammatory mediators. Stool collection: We collect stool samples from patients with bronchiectasis.Fresh stools were processed in the laboratory within 30 min after collection and stored at -80°C until analysis. Peripheral blood collection: We collect peripheral blood samples from patients with bronchiectasis to detect inflammatory mediators and so on.

Official Title
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Research on the Mechanism Affecting Progression of Bronchiectasis Based on Omics Method

Conditions
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Bronchiectasis

Intervention / Treatment
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* Other: Pseudomonas aeruginosa colonization infection
* Drug: Macrolides


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: 18 years or older Bronchiectasis confirmed by high-resolution computed tomographic scan(HRCT) Chronic expectoration with ability to provide a sputum sample at the study visit Provision of written informed consent Exclusion criteria: Traction bronchiectasis Lack of important clinical information

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pseudomonas aeruginosa colonization group<br>Colonization of Pseudomonas aeruginosa in the airways of patients with bronchiectasis | Other: Pseudomonas aeruginosa colonization infection<br>* With or without airway Pseudomonas aeruginosa colonization infection<br>|
| Non-Pseudomonas aeruginosa colonization group<br>No colonization of Pseudomonas aeruginosa in the airways of patients with bronchiectasis | Other: Pseudomonas aeruginosa colonization infection<br>* With or without airway Pseudomonas aeruginosa colonization infection<br>|
| Before treatment with macrolides<br>Before treatment with macrolides in patients with bronchiectasis | Drug: Macrolides<br>* Before or after 6 months of treatment with macrolides for patients with bronchiectasis<br>|
| After treatment with macrolides<br>After 6 months of treatment with macrolides for patients with bronchiectasis | Drug: Macrolides<br>* Before or after 6 months of treatment with macrolides for patients with bronchiectasis<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Acute exacerbations and mortality | The number of acute exacerbations and outcome (death or survival) of patients with bronchiectasis after one year. | February 10, 2026 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lung function | Forced expiratory volume in 1s (FEV1),Forced vital capacity（FVC） | February 10, 2026 | 
| Symptoms assessment | MRC score,cough score,sputum purulent score,sputum volume score and hemoptysis score | February 10, 2026 | 
| Stool and sputum microtioba | Stool and sputum microtioba from patients with bronchiectasis after one year | February 10, 2026 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Bronchiectasis, Microbiota, Pseudomonas aeruginosa