Elevated blood eosinophil counts in stable COPD patients in Belgian primary care: prevalence and clinical characteristics.

Objectives: Recently, eosinophilic Chronic Obstructive Pulmonary Disease (COPD) has been identified as a clinically relevant phenotype, as patients with elevated blood eosinophil counts (BEC) demonstrate a better response to maintenance inhaled corticosteroids (ICS). This real-world study in Belgian primary care describes the distribution of BECs and the ICS use in stable COPD patients.

Methods: This study retrospectively analysed data from two primary care practices using the most recent values retrievable from the electronic health record. Patients were dichotomized based on BEC GOLD thresholds of 100 and 300 cells/µL.

Results: Eighty stable COPD patients (60% male, mean (SD) age of 70.7 (9.7)years, mean FEV1 (SD) of 65.4 (17.5) % Predicted) were included. Amongst them, 46% used ICS maintenance therapy. BEC values ranged from 0 to 667 cells/µL with a median (IQR) of 182 (80-291) cells/µL. 71% and 23% of patients presented BEC > 100 and ≥ 300 cells/µL, respectively. The mean age in the BEC^≥300 group was significantly higher than in the BEC^<300 group (MD = 7.2 y; p = 0.005). No other significant differences in demographic characteristics, dyspnea, FEV1 % Predicted, ≥1 moderate/severe exacerbations in the previous year, current maintenance ICS use, number of comorbidities or Charlson Comorbidity Index were detected between groups.

Conclusion: In this primary care population in Belgium, elevated BECs and maintenance ICS use are prevalent. Besides age, clinical characteristics were comparable between eosinophil-based groups whether the 100 or 300 cells/µL threshold was used.

Trial registration: Not applicable given the retrospective nature of the study.