Personalised medicine in exacerbations of COPD: the beginnings.

E xacerbations of chronic obstructive pulmonary disease (COPD) are inflammatory events induced by infection [1]. Therefore, the use of antimicrobial and antiinflammatory medications in exacerbations appears logical. However, the evidence that antibiotics and corticosteroids are beneficial in the treatment of exacerbations is relatively sparse, and only a meta-analytic approach has given us sufficient confidence in the use of these treatments [2, 3]. Placebocontrolled and observational studies in hospitalised patients with COPD exacerbations have shown the benefit of antibiotics and steroids [4–6]. This has led to current recommendations for treating all hospitalised exacerbations with both antibiotics and steroids. However, as we appreciate the heterogeneity of infection and inflammation in exacerbations, using the same treatment in all exacerbations does not appear appropriate. Bacterial infection causes approximately 50% of exacerbations; therefore, antibiotic use is probably unnecessary in the other 50% [1]. Eosinophilic inflammation is seen in a third of exacerbations, so corticosteroids may be of limited benefit in a substantial proportion of exacerbations [7].