Comparison of Eosinophilic and Non-eosinophilic Cases with Chronic Obstructive Pulmonary Disease (COPD) in terms of Clinical Arrival, Exacerbations, Quality of Life and Response to Treatment: A Prospective Study

Chronic obstructive pulmonary disease (COPD) is a heterogeneous diseases. Biomarkers are tried to be defined in order to evaluate the differences in response to pharmacological therapies. The aim of this study was; to determine blood and sputum eosinophil levels in stable COPD patients and evaluate the annual number of exacerbations and inflammatory biomarkers (C-Reactive Protein, Fibrinogen) among groups with and without eosinophilia. Pulmonary functions, symptoms scores, inflammatory biomarkers (C-Reactive Protein, Fibrinogen) sputum and blood eosinophil levels were measured in patients with stable COPD who presented to our Chest Diseases outpatient clinic; Patients with sputum eosinophil level ≥3%, blood eosinophil level ≥2% and ≥ 200/µL were considered to be eosinophilic. The patients were prospectively followed-up for a 1-year period and the rates of exacerbation and exacerbation were recorded. No correlation was found between blood and sputum eosinophil values (p = 0.129). The number of exacerbations was found to be significantly higher according to blood eosinophil percentage and absolute value (p = 0.029)(figure 1-2). Although sputum eosinophilia was associated with the number of exacerbations in the previous year and the number of exacerbations of follow-up, it was not found statistically significant. There was no significant difference in CAT, mMRC, FEV1 variability and inflammatory biomarkers between the eosinophilic and non-eosinophilic groups. This study showed that more frequent follow-up is required in cases with eosinophilic phenotype.