Abstract
We aimed to describe the differences and similarities between patients with chronic obstructive airway disease classified on the basis of classical diagnostic labels (asthma, chronic obstructive pulmonary disease (COPD), or asthma–COPD overlap (ACOS)) or according to the underlying inflammatory pattern (Th-2 signature, either Th-2-high or Th-2-low).
We performed a cross-sectional study of patients aged ≥40 years and with a post-bronchodilator forced expiratory volume in 1 s to forced vital capacity ratio ≤0.7 with a previous diagnosis of asthma (non-smoking asthmatics (NSA)), COPD or ACOS, the latter including both smoking asthmatics (SA) and patients with eosinophilic COPD (COPD-e). Clinical, functional and inflammatory parameters (blood eosinophil count, IgE and exhaled nitric oxide fraction (FeNO)) were compared between groups. Th-2 signature was defined by a blood eosinophil count ≥300 cells·μL−1 and/or a sputum eosinophil count ≥3%.
Overall, 292 patients were included in the study: 89 with COPD, 94 NSA and 109 with ACOS (44 SA and 65 with COPD-e). No differences in symptoms or exacerbation rate were found between the three groups. With regards the underlying inflammatory pattern, 94 patients (32.2%) were characterised as Th-2-high and 198 (67.8%) as Th-2-low. The Th-2 signature was found in 49% of NSA, 3.3% of patients with COPD, 30% of SA and 49.3% of patients with COPD-e. This classification yielded significant differences in demographic, functional and inflammatory characteristics.
We conclude that a classification based upon the inflammatory profile, irrespective of the taxonomy, provides a more clear distinction of patients with chronic obstructive airway disease.
Abstract
Identifying a Th-2 signature in patients with chronic airflow limitation effectively differentiates treatable traits http://ow.ly/kq1E309MMkt
Footnotes
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Support statement: The project was endorsed by the COPD and Asthma Research Board of the Spanish Society of Respiratory Medicine (SEPAR). The project was partially funded by the Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III, Ministerio de Economia y Competitividad (FIS 15/01263) and by an unrestricted grant from Chiesi Pharmaceutici SpA. Chiesi had no role in the study design, data collection, data analysis, data interpretation, writing of the report, or in the decision to submit the article for publication. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication. Funding information for this article has been deposited with the Crossref Funder Registry.
Conflict of interest: Disclosures can be found alongside this article at erj.ersjournals.com
- Received December 6, 2016.
- Accepted March 2, 2017.
- Copyright ©ERS 2017