Involvement of Airway Eosinophilia and Airway Hyperresponsiveness in Management and Therapy for COPD>

This clinical study was designed to examine prevalence of eosinophilia and hyperresponsiveness in the airways in COPD who have no symptom and no past history of asthma, and to examine involvement of these pathophysiological features of asthma in management and therapy for COPD. Sputum examination via qualitative and quantitative procedures was performed in stable COPD (GOLD 1–3). When sputum eosinophils were qualitatively (≥+) or quantitatively assessed (≥3%), ciclesonide (ICS) was added on indacaterol (LABA). In cases with %FEV1 ≥ 70, acetylcholine provocation test was examined for assessment of airway hyperresponsiveness. Sputum eosinophils were observed in 65 of 129 subjects using qualitative analysis; in contrast, lower grade (>0%) and higher grade (≥3%) were observed in 15 and 25 of 74 subjects using quantitative analysis. Airway hyperresponsiveness developed in 46.9% of subjects with sputum eosinophils. Indacaterol significantly improved lung function (FEV1, IC) in subjects with airway eosinophilia. Exacerbations occurred much more frequently in lower-grade airway eosinophilia without ciclesonide than in higher-grade eosinophilia with ciclesonide. Airway hyperresponsiveness significantly increased frequency of exacerbations in subjects with airway eosinophilia. Addition of ciclesonide to indacaterol markedly improved lung function and CAT score in subjects with airway eosinophilia. However, ciclesonide was less effective in improving these values in subjects with airway hyperresponsiveness. Eosinophilia and hyperresponsiveness in the airways are complicated with 25–50% of COPD. These phenotypes are related to symptom stability and reactivity to LABA and ICS in COPD.