Back to Journals » International Journal of Chronic Obstructive Pulmonary Disease » Volume 12

Sputum cell count: biomarkers in the differentiation of asthma, COPD and asthma-COPD overlap

Authors Gao J, Zhou WT, Chen BD, Lin WM, Wu SF, Wu F

Received 23 May 2017

Accepted for publication 14 August 2017

Published 11 September 2017 Volume 2017:12 Pages 2703—2710

DOI https://doi.org/10.2147/COPD.S142466

Checked for plagiarism Yes

Review by Single-blind

Peer reviewers approved by Dr Charles Downs

Peer reviewer comments 3

Editor who approved publication: Dr Richard Russell

Jie Gao, Wutie Zhou, Bida Chen, Weiming Lin, Sifang Wu, Feng Wu

Department of Respiratory Medicine, The Third People’s Hospital, Guangzhou Medical College, Huizhou, People’s Republic of China

Introduction: Cell count in induced sputum is a noninvasive biomarker to assess airway inflammation phenotypes. Accordingly, sputum cell counts are extensively used in the treatment of asthma and COPD. Nevertheless, the clinical application of sputum cell counts in patients with asthma–COPD overlap (ACO) remains elusive. The aim of this study was to investigate sputum cell counts in patients with ACO which are different from those in patients with asthma and COPD and also to examine the relationship between sputum cell counts in bronchial reversibility and bronchial hyperresponsiveness (BHR).
Patients and methods: A total of 374 patients participated in the study, including 142 patients with asthma, 160 patients with COPD and 72 patients with ACO. All patients underwent the following tests on the same day: pulmonary function test (PFT), BHR test or bronchodilator reversibility test and inducing sputum. They were classified into the asthma group, COPD group or ACO group based on a clinical history, PFT values and BHR test or bronchodilator reversibility test.
Results: The three groups had different PFT values (p<0.001) except for forced vital capacity (FVC) between the asthma and ACO groups (p=0.378). The sputum levels of eosinophil% were decreased in patients with COPD when compared with those in patients with asthma and ACO (p<0.001 and p<0.001, respectively). There was a difference in sputum neutrophil% and macrophage% counts among the three groups (p<0.001 and p<0.001, respectively); there was no difference in sputum eosinophil% counts between patients with ACO and asthma (p=0.668) and there was no difference in the percentage of induced sputum cells between the stage of airway obstruction and the stage of BHR.
Conclusion: The clinical relevance of this study provides evidence that sputum cell counts as an inflammatory biomarker could carry some information to distinguish ACO, asthma and COPD, and these biomarkers need more studies to provide diagnostic value in the differentiation between ACO, asthma and COPD.

Keywords: induced sputum cell counts, COPD, BHR, bronchodilator reversibility, asthma, asthma–COPD overlap

Creative Commons License 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.

Download Article [PDF]  View Full Text [HTML][Machine readable]

 

Other article by this author:

Correlation between fractional exhaled nitric oxide and sputum eosinophilia in exacerbations of COPD

Gao J, Zhang M, Zhou LQ, Yang X, Wu HG, Zhang JF, Wu F

International Journal of Chronic Obstructive Pulmonary Disease 2017, 12:1287-1293

Published Date: 27 April 2017