[Study of the role of blood eosinophil count in patients with severe acute exacerbation of chronic obstructive pulmonary disease hospitalized in a Tunisian Center].

Introduction: There is a controversy over the relationship between blood eosinophil count (BEC) and the severity of chronic obstructive pulmonary disease (COPD) exacerbations. The purpose of our study was to determine the relationship between blood eosinophil count and multiple parameters in assessing the severity of serious acute exacerbation (AE) of obstructive pulmonary disease.

Methods: We conducted a retrospective monocentric study of hospitalized patients with obstructive pulmonary disease treated between 2005 and 2015. We compared 2 groups of patients: G1(BEC+): BEC ≥ 200 cell/μl (103 cases, 20.4%), G2(BEC-): BEC < 200 cell/μl (403 patients: 79.6%).

Results: A total of 506 subjects with obstructive pulmonary disease were included in the study. No significant difference between the two groups in age, gender, forced expiratory volume in one second (FEV1), and the number of AE/year (BEC+: 2.6, BEC-:2.5 AE/year; p = 0.48) was found. The analysis of the parameters of severity of serious AE showed no difference between the two groups in partial pressure of oxygen PaO2 measured on admission (60.5, 59.2 mmHg; p = 0.26), capnia (p=0.57), pH (p=0.74), C-reactive protein rate (mg/L) (82.7, 81; p = 0.89), leukocytosis (p = 0.36), non-invasive mechanical ventilation (5.8%, 6.5%; p = 0.81), invasive mechanical ventilation (p = 0.5),length of stay in hospital (9.7, 9 days; p = 0.21), mean time to next AECOPD (p = 0.32). Survival at 1 year was comparable between the two groups (94% vs 96%; Log Rank: 0.708).

Conclusion: Increased BEC in patients with COPD does not appear to have a negative effect on patients with severe AE. Despite the recent guidelines recommend to consider blood eosinophil count while making treatment decisions, the role and the prognostic interest of blood eosinophil count in patients with COPD could be population-dependent.