The different phenotypes of COPD.

BACKGROUND Chronic obstructive pulmonary disease (COPD) is associated with significant morbidity and mortality. To improve the health status and reduce symptom burden, it is important to identify a group of patients with similar characteristics and prognosis, called clinical phenotypes. Herein we shall review the different phenotypes of COPD. SOURCES OF DATA Keywords (COPD, phenotype, acute exacerbation) search was conducted in PubMed, Google Scholar. AREAS OF AGREEMENT Those with raised blood eosinophil counts respond better to steroid therapy at stable state and exacerbation. AREAS OF CONTROVERSY There is no universally accepted blood eosinophil cut-off value that will indicate favourable response to corticosteroids and potentially for future biologic therapy. GROWING POINTS There is an urgent need for further therapeutic options for COPD patients with non-eosinophilic inflammation. AREAS TIMELY FOR DEVELOPING RESEARCH Well-designed COPD trials with identification of phenotypes for more personalization of the treatment of COPD.