Bronchiectasis frequently coexists with asthma or COPD, forming an overlap phenotype that’s increasingly recognized but often overlooked. Patients with these overlap syndromes tend to experience more frequent exacerbations, higher hospitalization rates, and worse outcomes than those with either condition alone.1
Clinical and radiographic recognition
Cough, sputum production, and recurrent infections are common across bronchiectasis, asthma, and COPD, making the diagnosis of overlap syndromes challenging. High-resolution CT imaging is essential for diagnosis, especially for those with persistent symptoms or poor response to standard therapies. This is particularly true in those with frequent exacerbations or eosinophilia.2
A bronchoarterial ratio of > 1 is a common radiographic criterion for bronchiectasis. While objective findings like this improve diagnostic consistency, interpretation must be cautious, especially in advanced COPD, where traction bronchiectasis or vascular changes can mimic true bronchiectasis.
Shared mechanisms, distinct outcomes
These diseases share key biological features, including chronic airway inflammation, impaired mucociliary clearance, and microbial colonization (particularly Pseudomonas aeruginosa). Neutrophil-mediated inflammation is especially prominent in both bronchiectasis and COPD.3
Individuals with overlapping COPD and bronchiectasis tend to produce more daily sputum, have more frequent exacerbations, have worse lung function, have higher inflammatory biomarker levels, and are more likely to grow Pseudomonas on cultures. They also tend to have longer tobacco exposure histories. Overall, this group faces a higher risk of adverse outcomes, including mortality.2
In contrast, the asthma-bronchiectasis overlap is less clearly defined. Available data suggest that allergic features are more common, including rhinitis, elevated serum IgE, and blood eosinophilia. These individuals may require higher doses of corticosteroids and often report poorer symptom control with more frequent exacerbations. Interestingly, registry data suggest lower mortality in this group compared with those with bronchiectasis alone, potentially reflecting the therapeutic benefit of inhaled corticosteroids (ICS).4
Tools for better identification
To help recognize overlap syndromes more reliably, clinical tools like the Radiology, Obstruction, Symptoms, and Exposure (ROSE) criteria have been developed. In parallel, large registries, such as the European Bronchiectasis Registry (EMBARC), are enhancing our understanding of disease burden and shaping future research.5
Emerging areas of interest include acquired cystic fibrosis transmembrane conductance regulator dysfunction, immune dysregulation, and microbiome shifts that may drive the development of bronchiectasis. These emerging insights point toward a future of endotype-driven, personalized care.
Management considerations
Treatment of overlap syndromes should be individualized. Core bronchiectasis management—airway clearance, targeted antibiotics, and microbiologic monitoring—should be integrated with established treatments for asthma or COPD. Though not yet studied, macrolides may be especially useful in patients with bronchiectasis-COPD overlap. ICS should be used judiciously; in the absence of eosinophilia, their use in bronchiectasis-COPD overlap may increase the risk of respiratory infections. Conversely, in patients with eosinophilia, particularly in asthma-bronchiectasis overlap, ICS use has been associated with fewer exacerbations and improved survival.
Ultimately, these overlap syndromes likely represent distinct biological entities rather than simply more advanced disease. As we continue to refine our understanding of airway inflammation and microbial patterns, targeted therapies such as biologics and other anti-inflammatory agents may help deliver more personalized and effective care.
References
1. Barker AF, Karamooz E. Non-cystic fibrosis bronchiectasis in adults: a review. JAMA. 2025;334(3):253-264. doi:10.1001/jama.2025.2680
2. Shi L, Wei F, Ma T, Zhou W, Li M, Wan Y. Impact of radiographic bronchiectasis in COPD. Respir Care. 2020;65(10):1561-1573. doi:10.4187/respcare.07390
3. Chalmers JD, Metersky M, Aliberti S, et al. Neutrophilic inflammation in bronchiectasis. Eur Respir Rev. 2025;34(176):240179. doi:10.1183/16000617.0179-2024
4. Polverino E, Dimakou K, Traversi L, et al. Bronchiectasis and asthma: data from the European Bronchiectasis Registry (EMBARC). J Allergy Clin Immunol. 2024;153(6):1553-1562. doi:10.1016/j.jaci.2024.01.027
5. Polverino E, De Soyza A, Dimakou K, et al. The association between bronchiectasis and chronic obstructive pulmonary disease: data from the European Bronchiectasis Registry (EMBARC). Am J Respir Crit Care Med. 2024;210(1):119-127. doi:10.1164/rccm.202309-1614OC
