IGHE and chronic obstructive pulmonary disease: Inversely, the present study showed that subjects with ACO shared the similar biological characteristics of asthma such as hypereosinophilia, increased total IgE, and high levels of FENO but also the functional characteristics of COPD such as distal airflow limitation, significant decreased DLCO, and low levels of 6MWD and VO2 max (Table 2).