Role of Eosinophil Count and Percentage in Chronic Obstructive Pulmonary Disease Exacerbation: A Retrospective Observational Study

Aim: To reveal the role of eosinophil count and percentage evaluated at the time of presentation in patients hospitalized with the exacerbation of chronic obstructive pulmonary disease (COPD). Material and Methods: In this study, the data of patients with a diagnosis of the exacerbation of COPD, who presented to the emergency department, and admitted to the general internal medicine ward, were retrospectively analyzed. The relationship of eosinophil count and ratios with the length of hospital stay and intensive care requirement was investigated.The Spearman correlation analysis was used for investigating correlation between parameters and outcome. Results: Of the study population, 39.7% were female and 60.3% were male. The ages of the participants ranged from 25 to 94 years, with a median value of 76 years. There was no significant correlation between the length of stay in ward and eosinophil count and percentage (rho=-0.148, p=0.066 and p=0.074, rho=-0.143, respectively) (Spearman correlation test). The group admitted to the intensive care unit had a significantly higher eosinophil count and percentage of eosinophils than the group that did not require intensive care (0.81(Inter Quarter Range (IQR):0.41-1.31) versus 1.32 (IQR:0.83-1.43) p=0.042 and 1.0 (IQR:0.81-1.21) versus 1.42 (IQR:1.02-1.64), p=0.018, respectively) (Mann Whitney U test). Conclusion: There was no correlation between a high eosinophil count and percentage and the length of hospital stay. However, the number and percentage of eosinophils were significantly higher among the patients requiring intensive care.