Asthma and COPD Overlap

Excerpt

Asthma and chronic obstructive pulmonary disease (COPD) are the most common obstructive lung diseases observed during clinical practice. They have common characteristics and similar clinical presentation. Moreover, they usually have the same presentation on pulmonary function tests (PFT). Therefore, the term "asthma-COPD overlap" (ACO) was used to describe the cases in that they have both features of asthma and COPD. Gibson first described ACO in 2009.

ACO is defined as an obstructive lung condition with clinical and inflammatory characteristics of asthma and COPD or predominantly COPD combined with bronchodilator responsiveness and elevated peripheral eosinophils count. Although the condition has now started to be described more, the last Global Initiative for Chronic Obstructive Lung Disease (GOLD) did not use ACO as a distinct condition, given there is no universally accepted definition.

The definition used commonly for ACO is the presence of airflow obstruction in individuals with a history of asthma and older than 40. According to the Global Initiative for Asthma (GINA) and GOLD, patients usually have chronic airway disease symptoms with cough, wheezing, recurrent lower respiratory tract infection, and asthma and COPD features. This review will describe the clinical presentation, evaluation, and management of patients with ACO.