Chronic obstructive pulmonary disease acute exacerbation: prognostic value of eosinophilia in terms of recurrence.

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) acute exacerbation (AE) increases morbidity and has an impact on health status. Inflammation plays a key role in these events. Current evidence supports use of biomarkers to guide corticosteroid therapy, which is included in the treatments of COPD AE.

AIM: The aim of our study was to determine the prognostic value of hypereosinophilia (HEo +) in patients admitted to emergency department (ED) with COPD AE in terms of recurrence (Recurrence+).

METHODS

A prospective and observational study was conducted over nine months including patients admitted to ED with COPD AE. Patient history, clinical, paraclinical and therapeutic data was collected. HEo+, was defined as blood eosinophil count (BEC)≥200 cells/mm3. One month follow-up was performed. We compared two groups: Recurrence+ vs Recurrence- patients and HEo+ vs HEo- patients. Both univariate and multivariate analysis were performed to identify factors associated with COPD AE recurrence at one month.

RESULTS

We included 252 patients. Prevalence of HEo+ was 50%. Patients with HEo+ had less severe clinical signs on admission (p=0.03), less COPD AE recurrence (p <0.001) and required less hospitalization at one month (p=0.003). Mortality was higher in HEo- patients (p=0.05). Recurrence- patients had HEo+ more frequently (61% vs 19% ; p<0.001). In multivariate analysis, we identified two predictors of recurrence of COPD: COPD group D (adjusted OR 2,3; [95% IC 1,5-3,7]; p<0,001) and non-invasive ventilation on admission (adjusted OR 3,9; [95% IC 1,1-13]; p=0,03). HEo+ was a protective factor of COPD group D (adjusted OR 2,3; [95% IC 1,5-3,7]; p-0,001) and non-invasive ventilation on admission (adjusted OR 3,9; [95% IC 1,1-13]; p=0,03). HEo+ was a protective factor of COPD AE recurrence (adjusted OR 0,3; [95% CI] [0,17-0,4]; p-0,001).

CONCLUSION

Recurrence of COPD AE one month after ED visit was less frequent in patients with HEo+. BEC may predict systemic corticosteroid treatment failure or success. Identification of responders to corticotherapy can lead to less prescription of prednisone or equivalent and could be integrated into a therapeutic management algorithm.