PT - JOURNAL ARTICLE AU - Helen F. Ashdown AU - Margaret Smith AU - Emily McFadden AU - Ian D. Pavord AU - Chris C. Butler AU - Mona Bafadhel TI - Blood eosinophils to guide inhaled maintenance therapy in a primary care COPD population AID - 10.1183/23120541.00606-2021 DP - 2021 Jan 01 TA - ERJ Open Research PG - 00606-2021 4099 - http://openres.ersjournals.com/content/early/2021/11/11/23120541.00606-2021.short 4100 - http://openres.ersjournals.com/content/early/2021/11/11/23120541.00606-2021.full AB - Blood eosinophils are a potentially useful biomarker for guiding inhaled corticosteroid (ICS) treatment decisions in COPD. We investigated whether existing blood eosinophil counts predict benefit from initiation of ICS compared to bronchodilator therapy.We used routinely collected data from UK primary care in the Clinical Practice Research Datalink. Participants were ≥40 years with COPD, ICS-naïve and starting a new inhaled maintenance medication (intervention group: ICS; comparator group: long-acting bronchodilator, non-ICS). Primary outcome was time-to-first exacerbation, compared between ICS and non-ICS groups, stratified by blood eosinophils (“high” (≥150/µL) and “low” (<150/µL) groups).Of 9475 eligible patients, 53.9% initiated ICS and 46.1% non-ICS treatment with no difference in eosinophils between treatment groups (p=0.71). Exacerbation risk was higher in patients prescribed ICS than non-ICS, but with a lower risk in those with “high” eosinophils (hazard ratio 1.04, 95% CI 0.98 to 1.10) than “low” eosinophils (1.19, 95% CI 1.09 to 1.31) (p value for interaction=0.01). Risk of pneumonia hospitalisation with ICS was greatest in those with “low” eosinophils (hazard ratio 1.26, 95% CI 1.05 to 1.50; p value for interaction=0.04). Results were similar whether the most recent blood eosinophil count or the mean of blood eosinophil counts was used.In a primary care population, the most recent blood eosinophil count could be used to guide initiation of ICS in COPD patients. We suggest that ICS should be considered in those with higher eosinophils and avoided in those with lower eosinophils (<150/µL).FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflicts of interest: Helen Ashdown reports support for the present manuscript from National Institute for Health Research. Consulting fees and payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events received from Boehringer Ingelheim, outside the submitted work.Conflicts of interest: Margaret smith has nothing to disclose.Conflicts of interest: Emily McFadden has nothing to disclose.Conflicts of interest: Dr. Pavord reports other from Sanofi, other from Regeneron Pharmaceuticals, Inc., non-financial support from Excerpta Medica, during the conduct of the study; other from Aerocrine AB, other from Almirall, other from AstraZeneca, other from Boehringer Ingelheim, grants and other from Chiesi, other from GSK, other from Novartis, other from Regeneron Pharmaceuticals, Inc, other from Sanofi, other from Teva , other from Circassia, other from Dey Pharma, other from Genentech, other from Knopp Biosciences, other from Merck, other from MSD, other from Napp Pharmaceuticals, other from RespiVert, other from Schering-Plough, outside the submitted work.Conflicts of interest: Chris C. Butler has nothing to disclose.Conflicts of interest: Mona Bafadhel reports grants or contracts from AZ. Payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events received from AZ, GSK, Chiesi, Cipla and Roche. Participation on a Data Safety Monitoring Board or Advisory Board for AZ and GSK. Stock or stock options held for Albus Health. Disclosures made outside the submitted work.