Prevalence of blood eosinophilia and its impact on lung functions in stable chronic obstructive pulmonary disease patients

ABSTRACT Background and Objective: Chronic obstructive pulmonary disease (COPD) is marked by persistent airflow limitation. Blood eosinophilia has emerged as a potential biomarker for predicting the risk of exacerbations as well as response to inhaled corticosteroids (ICS). However, its impact on lung function in stable COPD remains uncertain. This study aimed to assess the prevalence of blood eosinophilia in stable COPD patients and explore its relationship with lung function, exercise capacity and exacerbation history. Methods: A total of 60 stable COPD patients were included in this cross-sectional study, selected according to specific inclusion and exclusion criteria. Blood eosinophil counts were measured, with eosinophilia defined as ≥2%. Lung function was evaluated through spirometry, while exercise capacity was assessed using the 6-minute walk test (6MWT). Statistical tests were applied to compare data between the eosinophilic and non-eosinophilic groups. Results: Eosinophilia was present in 21.67% of patients. Eosinophilic patients had a higher rate of exacerbations (53.85%) and a lower FEV1 (mean 39.46% predicted) as compared to non-eosinophilic patients (17.02% and 50.79%, respectively). The 6MWT distance was shorter in eosinophilic patients (249.38 meters) as compared to non-eosinophilic patients (274.17 meters). Conclusion: Eosinophilic inflammation in COPD significantly impacts exacerbation risk, lung function and exercise capacity . Eosinophil counts may prove to be a useful biomarker for identifying COPD patients who are more likely to benefit from targeted treatments, such as inhaled corticosteroids (ICS).