Background: The responsibility of eosinophilic inflammation in chronic obstructive pulmonary disease (COPD) exacerbations is hardly observed compared to asthma. We, therefore, aimed to study the possible function of eosinophilic airway inflammation (EAI) on acute exacerbations' result in COPD-patients.
Methods: A total of 34 of exacerbated COPD patients were included in an observational prospective cohort study. Total leucocytic count, eosinophils, neutrophils count, and sputum eosinophils were then measured on admission, which were repeated after 3 months of stabilizing the exacerbated chest condition. Evaluation of patient's outcome of exacerbation, Spirometric ventilatory function testing after stabilization, follow up of all patients every 3 months for one year, and reassessing mMrc scale and CAT score were also performed.
Results: The mean age of the included 34-exacerbated COPD patients in our study was about 65.3±6.9 years, where most of them were males (70.6%). Additionally, 55.8, 55.9, and 44.1% of the patients were smokers, admitted at ward, and admitted at ICU, separately. Blood eosinophil (≥2%) and sputum eosinophilia (>1.25%) were presented in 32.4% of the current patients. Most importantly, no statistically significant correlation among eosinophil levels on admission and the exacerbation outcome was noted. Analogously, no statistically significant variation among patients with low and high eosinophils levels for their mMRC-grade and CAT-score at charge after 3, 6, and 9 months of follow up.

Conclusion: EAI constitutes a lesser part besides neutrophilic inflammation in COPD exacerbations. There was an irrelevant correlation among eosinophils ratios at admission and the outcome.

Keywords: COPD; Exacerbation; Eosinophils; Inflammation.