Asthma COPD Overlap (ACO)

Abstract

Asthma and chronic obstructive pulmonary disease (COPD) are the most common chronic airway disorders worldwide. The overlap of asthma and COPD is a problem that has been discussed for a long time, and there was previously no unified name or definition of this condition. The Global Initiative for Asthma (GINA), an international committee examining asthma, and the Global Initiative for Chronic Obstructive Lung Disease (GOLD), an international committee examining COPD, jointly proposed the concept of “Asthma/COPD Overlap Syndrome (ACOS)” (currently named “asthma/COPD overlap (ACO).” However, it is unclear how to identify ACO as a clinically useful disease entity. In this chapter, we discussed clinical features and biomarkers to differentiate asthma, COPD, and ACO in elderly patients on the basis of the definition of GINA guideline and described historical background and prevalence and treatment of ACO.