Clinical Characteristics of Patients With Chronic Obstructive Pulmonary Disease With Comorbid Bronchiectasis: A Systemic Review and Meta-analysis

Abstract

Background: In the 2014 Global initiative for chronic Obstructive Lung Disease guidelines, bronchiectasis was for the first time defined as a comorbidity of chronic obstructive pulmonary disease (COPD), and this change has been retained in the 2015 update, which emphasizes the influence of bronchiectasis in the natural history of COPD. The present meta-analysis was aimed at summarizing the impact of bronchiectasis on patients with COPD. Methods: Databases including Embase, PubMed, and the Cochrane Central Register of Controlled Trials were searched comprehensively to identify all relevant human clinical studies published until August 2014. Bronchiectasis was confirmed either by computed tomography or high-resolution computed tomography. One or more clinicopathological or demographical characteristics, including age, sex, smoking history, daily sputum production, exacerbations, inflammatory biomarkers, lung function, and colonization by potentially pathogenic microorganisms (PPMs), were compared between COPD patients with and without bronchiectasis. Results: Six observational studies with 881 patients were included in the meta-analysis. The mean prevalence of bronchiectasis in patients with COPD was 54.3%, ranging from 25.6% to 69%. Coexistence of bronchiectasis and COPD occurred more often in male patients with longer smoking history. Patients with COPD and comorbid bronchiectasis had greater daily sputum production, more frequent exacerbation, poorer lung function, higher level of inflammatory biomarkers, more chronic colonization by PPMs, and higher rate of Pseudomonas aeruginosa isolation. Conclusion: In spite of the heterogeneity between included studies and detectable publication bias, this meta-analysis demonstrated the impact of bronchiectasis in patients with COPD in all directions, indicating that coexistence of bronchiectasis should be considered a pathological phenotype of COPD, which may have a predictive value.

British Thoracic Society Guideline for bronchiectasis in adults

“…Other features that distinguished patients with COPD and bronchiectasis from COPD alone included greater daily sputum production, higher exacerbation frequency, worse lung function, higher levels of inflammatory biomarkers, increased colonisation by potential pathogenic micro-organism (PPM) and increased rate of Pseudomonas aeruginosa ( P. aeruginosa ) colonisation. 16 A systematic review and meta-analysis of 14 observational studies in COPD patients found that the presence of bronchiectasis was associated with worse airflow obstruction, isolation of PPM, increased risk of exacerbation and of mortality. 17 …”

Exacerbations of COPD

“…Mortality was only slightly higher in the subgroup with many comorbidities and evidence of systemic inflammation. Bronchiectasis A meta-analysis of six observational studies demonstrated a correlation between the detection of bronchiectasis in (high-resolution) computed tomography in patients with COPD and the frequency of exacerbations (weighted mean difference 1.54 times in the previous year) [14]. Since these patients with bronchiectasis had more chronic colonisation by pathogenic microorganisms (odds ratio 7.33) and a higher rate of Pseudomonas aeruginosa isolation (odds ratio 3.5), this coexistence is considered a potential mechanism for frequent exacerbations.…”

Bronchiectasis in Chronic Obstructive Airway Disease: More than a Comorbidity?

“…There has only been one study analysing the impact of bronchiectasis on the quality of life Finally, one of the most consistently evident factors is the propensity of patients with bronchiectasis-associated COPD to have not only more exacerbations [14][15][16][17] but also ones that are more severe 13,15,17,20 and longer-lasting 9 , although not all authors have found this association 18,19,24 . Taken together, however, both the meta-analyses 28,29 found a relationship between exacerbations and bronchiectasis ( Table 3).…”

“…These differences are not limited to clinical factors but also involve functional, microbiological, inflammatory and even prognostic and therapeutic factors, which has led some authors to conclude that there is a specific clinical phenotype of COPD patients with bronchiectasis. Table 3 shows the results of the two meta-analyses published to date 28,29 .…”