Correlations between exacerbation rate and blood eosinophil levels in COPD patients

Introduction: Some patients with COPD are prone to develop frequent exacerbations. The identification of biomarkers able to predict exacerbation frequency will give the opportunity to apply tailored pharmacological strategies to these patients. Recently, there has been interest in blood eosinophils as predictor of corticosteroid responsiveness in preventing exacerbation. Aim: To evaluate blood eosinophil levels in COPD patients with frequent (≥2 episodes per year) or infrequent (≤1 episodes per year) exacerbations. Methods: Single-centre retrospective cohort study. Patients were included in the analysis if regularly followed for at least 2 years and if a blood cell count was performed as routine practice in stable condition within 6 months prior to study analysis. Results: 142 COPD patients were included in the analysis (age 72.5±6.8 years; post-BD FEV1% 55.5±13.8% predicted). 32% of patients met the criteria of frequent exacerbators. No difference in: lung function; demographic characteristics and inhaled treatments were found between frequent and infrequent excacerbators. Significant higher blood eosinophil levels were found in frequent vs infrequent excacerbators (296±37 vs 202.60±14 cells/mcl respectively; p 0.05). Among subjects with severe airflow obstruction, patients with frequent exacerbations had significantly higher eosinophil levels than those with infrequent exacerbations (p Conclusions: In our cohort of COPD patients, higher levels of blood eosinophil counts were found in subjects with frequent exacerbations.