Clinical phenotypes of COPD: identification, definition and implications for guidelines.

The term phenotype in the field of COPD is defined as "a single or combination of disease attributes that describe differences between individuals with COPD as they relate to clinically meaningful outcomes". Among all phenotypes described, there are three that are associated with prognosis and especially are associated with a different response to currently available therapies. There phenotypes are: the exacerbator, the overlap COPD-asthma and the emphysema-hyperinflation. The exacerbator is characterised by the presence of, at least, two exacerbations the previous year, and on top of long-acting bronchodilators, may require the use of antiinflammatory drugs. The overlap phenotype presents symptoms of increased variability of airflow and incompletely reversible airflow obstruction. Due to the underlying inflammatory profile, it uses to have a good therapeutic response to inhaled corticosteroids in addition to bronchodilators. Lastly, the emphysema phenotype presents a poor therapeutic response to the existing antiinflammatory drugs and long-acting bronchodilators together with rehabilitation are the treatments of choice. Identifying the peculiarities of the different phenotypes of COPD will allow us to implement a more personalised treatment, in which the characteristics of the patients, together with their severity will be key to choose the best treatment option.