Smoking gun: when COPD therapies fail current smokers

Chronic obstructive pulmonary disease (COPD) is mainly treated with bronchodilators (long-acting beta-agonists (LABA) and/or long-acting muscarinic antagonists (LAMA)) to reduce symptoms and exacerbations. Inhaled corticosteroids (ICS) are also frequently used, more recently in the form of single inhaler triple therapy (SITT).1–3 There are numerous established adverse effects of ICS (pneumonia, mycobacterial infection, cataracts, glaucoma, thrush, bruising, osteoporosis, adrenal insufficiency—and the list goes on),4 5 with more potent adverse outcomes (pulmonary embolism, cardiovascular disease, type 2 diabetes) having recently been reported in association with high-dose ICS in asthma.6 7 In view of the potential harms of ICS, the increasingly one-size-fits-all use of SITT in COPD1 8 is a growing concern which must be balanced against the therapeutic benefits of ICS (decreased exacerbations, improved lung function and, perhaps, decreased mortality/cardiovascular events).2 3 9 10 To better specify the place of ICS in COPD, it has been proposed to classify patients based on exacerbation rates and blood eosinophil counts.1 This may identify patients who would benefit from ICS, with higher blood eosinophil counts (ideally ≥0.3×109/L) acting as an important prognostic (predicting exacerbations/readmissions)11 and theragnostic (predicting responsiveness to ICS or type 2 targeting biologics) marker.2 3 12 Crucially, such stratification could avoid adverse effects of ICS in patients who experience no …