Back to Journals » International Journal of Chronic Obstructive Pulmonary Disease » Volume 7

Sputum eosinophilia can predict responsiveness to inhaled corticosteroid treatment in patients with overlap syndrome of COPD and asthma

Authors Kitaguchi Y, Komatsu, Fujimoto K, Hanaoka M, Kubo K

Received 7 February 2012

Accepted for publication 14 March 2012

Published 12 April 2012 Volume 2012:7 Pages 283—289

DOI https://doi.org/10.2147/COPD.S30651

Review by Single anonymous peer review

Peer reviewer comments 3



Yoshiaki Kitaguchi1,*, Yoshimichi Komatsu1,*, Keisaku Fujimoto2, Masayuki Hanaoka1, Keishi Kubo1
1First Department of Internal Medicine, Shinshu University School of Medicine, 2Department of Biomedical Laboratory Sciences, Shinshu University School of Health Sciences, Matsumoto, Japan

*These authors contributed equally to this work

Background: Chronic obstructive pulmonary disease (COPD) and asthma may overlap and converge in older people (overlap syndrome). It was hypothesized that patients with overlap syndrome may have different clinical characteristics such as sputum eosinophilia, and better responsiveness to treatment with inhaled corticosteroid (ICS).
Methods: Sixty-three patients with stable COPD (forced expiratory volume in 1 second [FEV1] ≤80%) underwent pulmonary function tests, including reversibility of airflow limitation, arterial blood gas analysis, analysis of inflammatory cells in induced sputum, and chest high-resolution computed tomography. The inclusion criteria for COPD patients with asthmatic symptoms included having asthmatic symptoms such as episodic breathlessness, wheezing, cough, and chest tightness worsening at night or in the early morning (COPD with asthma group). The clinical features of COPD patients with asthmatic symptoms were compared with those of COPD patients without asthmatic symptoms (COPD without asthma group).
Results: The increases in FEV1 in response to treatment with ICS were significantly higher in the COPD with asthma group. The peripheral eosinophil counts and sputum eosinophil counts were significantly higher. The prevalence of patients with bronchial wall thickening on chest high-resolution computed tomography was significantly higher. A significant correlation was observed between the increases in FEV1 in response to treatment with ICS and sputum eosinophil counts, and between the increases in FEV1 in response to treatment with ICS and the grade of bronchial wall thickening. Receiver operating characteristic curve analysis revealed 82.4% sensitivity and 84.8% specificity of sputum eosinophil count for detecting COPD with asthma, using 2.5% as the cutoff value.
Conclusion: COPD patients with asthmatic symptoms had some clinical features. ICS should be considered earlier as a potential treatment in such patients. High sputum eosinophil counts and bronchial wall thickening on chest high-resolution computed tomography might therefore be a good predictor of response to ICS.

Keywords: COPD, asthma, HRCT, inhaled corticosteroid, pulmonary function

Creative Commons License © 2012 The Author(s). This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.