Blood eosinophilia in chronic obstructive pulmonary disease: impact on exacerbations risk and severity

Abstract

Introduction: COPD a chronic respiratory disease, is currently considered as a true systemic disease, responsible for systemic inflammation. Blood eosinophils seem to be associated, with a greater exacerbation risk and severity. Tunisian data on this subject are scarce.

Aim: To study the impact of blood hypereosinophilia on risk and severity of COPD exacerbations,

Methods: This prospective study was conducted, including patients followed for COPD. They were assessed as stable and followed for one year. We had divided our study population into two groups according to blood eosinophilia. A threshold for hypereosinophilia of 200 elements/mm3 was defined.

Results: They were 120 patients, with mean age of 65 years and sex ratio of 8.23. Eosinophilic patients (n=49, 40.8%) were not more exacerbating (p=0.49). In These patients, moderate exacerbation was significantly more common (p <0,000). This was confirmed in multivariate analysis blood hypereosinophilia exposed to 2.62 times higher risk of moderate exacerbation (p = 0.001; OR 2.62; 95% CI [1.02 - 1.43]). Blood eosinophilia was not predictive of hospitalization. A significant negative correlation was found in our series between eosinophilia rate and hospitalization rate (p=0.04, r=-0.18). The length of hospital stay was longer with hypereosinophilia (p = 0.05).

Conclusions: Our results support the heterogeneity of data in literature. While they are inconsistent with some data in the literature, they agree with Tunisian results where blood eosinophilia doesn’t predict a greater risk of exacerbation but exposes to a greater risk of moderate exacerbation.