Blood eosinophil guided prednisolone therapy for exacerbations of COPD: a further analysis

To the Editor: Exacerbations of chronic obstructive pulmonary disease (COPD) are associated with significant morbidity and mortality 1. Current guidelines advocate the use of systemic corticosteroids in addition to antibiotics to treat an exacerbation 2, 3, but these treatments are not universally effective and are not without harm 4. Individualised treatment may, therefore, be an advance. Recently we showed that patients with a peripheral blood eosinophil count of ≥2% at the onset of an outpatient managed exacerbation respond promptly and completely to prednisolone, whereas those with a count of <2% had a higher rate of treatment failure compared with placebo 5. Whether these findings can be replicated in a larger population, including patients hospitalised with exacerbations of COPD remains unclear. We set out to address these questions in a further analysis of randomised controlled studies comparing outcomes in patients with exacerbations of COPD treated with prednisolone or non-prednisolone (placebo or equivalent). We investigated the rates of treatment failures in patients stratified by the peripheral blood eosinophil count measured at the time of exacerbation. A literature search of the Medline, EMBASE and PubMed databases was performed using the MeSH terms: 1) chronic obstructive pulmonary disease; 2) exacerbations; 3) oral corticosteroid/prednisolone; and 4) randomised clinical trials. Six trials fulfilled these criteria and the authors were contacted about data sharing. Of these studies, the peripheral blood eosinophil count at the onset …