Distribution of Blood Eosinophils Among Patients with COPD in Primary Care

Rationale: In COPD, a higher level of blood eosinophils [EOS] may relate to an increased risk of exacerbations (AECOPD) [Vedel-Krogh, 2016] and is a promising biomarker of response to treatment with inhaled corticosteroids (ICS) [Pascoe, 2015]. We report the distribution of blood EOS levels in a primary care cohort of COPD patients. Methods: The ACCESS (Assessment of Comorbidities in COPD in European Symptomatic Subjects) was an observational study that prospectively recruited COPD patients across 5 European countries. There were minimal exclusion criteria, but patients with current asthma were excluded. White blood cell count (WBC), including EOS, was analyzed in local laboratories. Results: In a cohort of 2785 patients, mean blood EOS levels were 159 cells/µL or 2.2% of total WBC. Blood EOS ≥150 cells/µL or ≥2% were seen in 67% and 72% of patients respectively. Removing current users of ICS resulted in a minor difference in mean value (Non-users [N=1382] vs Users: 162 vs 157 cells/µL). No clinically important differences in EOS distribution were observed with any demographic or key clinical variables or exacerbations. Conclusions: In this post-hoc analysis, two thirds of COPD patients in primary care have blood EOS levels above the 150cells/µL level proposed as a threshold value to indicate potential benefit from ICS. Current use of ICS has minimal impact on EOS at a population level. Funding: GSK [115058; NCT01516528]