Airflow limitation in chronic obstructive pulmonary disease (COPD) is associated with influx of various inflammatory cells (e.g. eosinophils, neutrophils, lymphocytes, macrophages) into the airways. Approximately one-third of stable COPD patients and one in five COPD exacerbations are associated with eosinophilic bronchitis that usually responds to inhaled or ingested corticosteroids . Specific anti-eosinophil agents like mepolizumab, a humanised monoclonal antibody against interleukin 5 (IL-5), reduce severe asthma exacerbations and improve lung function [2–4]. The improvement in forced expiratory volume in 1 s (FEV1) is also associated with a decrease in biomarkers of airway remodelling, such as sputum hyaluronan and versican, over a 6-month treatment period . It is not known if the same benefits are observed in patients with COPD and eosinophilia in whom the airflow obstruction is due to cigarette smoke-related bronchitis and emphysema.
Eosinophils may not directly contribute to luminal obstruction in COPD although they may predict steroid response http://ow.ly/b3Au308wA0m
Clinical trial registration: NCT01463644.
Support statement: This study was funded by the Canada Research Chair program and GlaxoSmithKline. Funding information for this article has been deposited with the Open Funder Registry.
Conflict of interest: Disclosures can be found alongside this article at erj.ersjournals.com
- Received November 14, 2016.
- Accepted December 20, 2016.
- Copyright ©ERS 2017