IGHE and chronic obstructive pulmonary disease: COPD, chronic obstructive pulmonary disease; CSs, corticosteroids; FeNO, fractioned exhaled nitric oxide; FEV1/FVC, forced expiratory volume of first second/forced vital capacity; ICS, inhaled corticosteroids; IgE, serum immunoglobulin E; LABA, long-acting beta-agonist; LAMA, long-acting muscarinic antagonist; Pro-BNP, pro-brain natriuretic peptide