Relationship between the presence of bronchiectasis and acute exacerbation in Thai COPD patients

Abstract

Background: The prevalence rate of bronchiectasis in COPD is variable. Coexisting bronchiectasis and COPD may influence COPD severity and exacerbation.

Objective: We investigated whether bronchiectasis is associated with frequent or severe COPD exacerbation. Lower airway bacterial and mycobacterial infections are a possible mechanism for bronchiectasis.

Materials and methods: A cross-sectional study was conducted in 2013-2014. COPD exacerbations and hospitalizations were reviewed. Spirometry and CT were performed. COPD symptoms were assessed by using the COPD assessment test (CAT) and modified Medical Research Council (mMRC) dyspnea scale. Sputum inductions were performed and specimens were sent for microbiology.

Results: We recruited 72 patients. Global Initiative for Chronic Obstructive Lung Disease (GOLD) A, B, C, and D, were noted in 20%, 27.1%, 14.3%, and 38.6% of the patients, respectively. Frequent exacerbations (≥2) and/or ≥1 hospitalization in the previous year were observed in 40.3% of patients. Median mMRC of COPD with frequent and non-frequent exacerbations was 1.0 (range 1-2) and 2.0 (range 1-3), (p=0.002), respectively. Median CAT of COPD with frequent and non-frequent exacerbations was 20.5 (3-37) and 11.0 (2-32), (p=0.004), respectively. CT-detected bronchiectasis was observed in 47.2% of patients. Median mMRC of COPD with and without bronchiectasis was 1.0 (0-4) and 1.0 (0-4) (p=0.22), respectively. Median CAT of COPD with and without bronchiectasis was 16.2 (95% CI: 12.9-19.6) and 13.0 (3-37), (p=0.49), respectively. The lower post-bronchodilator forced expiratory volume in 1 second (FEV₁) of COPD with frequent exacerbations than those without was noted (p=0.007). The post-bronchodilator forced expiratory volume at 1 second percent in patients with and without bronchiectasis was not different (p=0.91). After adjusting for gender, severity of airflow obstruction, severity of COPD symptoms, the odds ratio for bronchiectasis with frequent and/or severe exacerbation was 4.99 (95% CI: 1.31-18.94), (p=0.018). Neither bacterial nor mycobacterial airway infection was associated with bronchiectasis or frequent exacerbation.

Conclusions: Bronchiectasis is common in Thai COPD. It was associated with frequent exacerbation or hospitalization. Mycobacterial tuberculosis in COPD patients with bronchiectasis was uncommon.

Keywords: COPD; bacteria; bronchiectasis; computed tomography; exacerbation; mycobacterium; prevalence; sputum.

Figure 1

Axial CT image with a lung-window setting showing diffuse emphysema with varicose bronchiectasis in the right lower lobe and tubular bronchiectasis in the left lower lobe. Abbreviation: CT, computed tomography.

Figure 2

Axial CT images with a lung-window setting showing tubular bronchiectasis with the signet ring sign in the right lower lobe (A–C) and the tram-track sign in the left lower lobe (B). Abbreviation: CT, computed tomography.

Figure 3

Axial CT images with a lung-window setting showing combined tubular and varicose bronchiectasis, emphysema and fibrosis in bilateral upper lobes (A), right middle lobe (B) and right lower lobe (B). Abbreviation: CT, computed tomography.

Figure 4

Axial CT images with a lung-window setting showing severe centrilobular emphysema and bronchiectasis in both lungs (A–C). Abbreviation: CT, computed tomography.

Figure 5

Axial CT image with a lung-window setting showing emphysema and bronchial wall thickening in bilateral lower lobes. Abbreviation: CT, computed tomography.

Figure 6

Axial CT images with a mediastinal-window setting showing a dilated main pulmonary artery (A) and calcifications of the aorta and coronary arteries (B–C). Abbreviation: CT, computed tomography.