Introduction: Blood eosinophils are proposed as a biomarker for treatment decisions, both on stable COPD and in COPD exacerbations. In this prospective observational study, we evaluated the impact of blood eosinophils on admission on the outcome of hospitalized COPD exacerbations. Methods: We evaluated consecutive patients hospitalized for COPD exacerbations in 5 tertiary hospitals in Greece. Patients >40 years with a previous COPD diagnosis were eligible; patients with other diagnoses or reasons for admission were excluded. Blood eosinophils were measured on admission prior to the initiation of treatment. Patients received standard care and followed up for a year. Results: A total of 388 patients were included in the study (84% male, age [meanSD] 714 years). On admission, patients with higher blood eosinophils (>2%) had higher FEV1, higher PaO2/FiO2 ratio, less dyspnea on Borg scale and lower CRP. Patients with higher eosinophil counts were discharged earlier (5.3 ±3.0 vs. 11.6±8.5 days for >2% and <2%, respectively). On the first 30 days from admission, 38 patients died, all of whom had <2% blood eosinophils; 65 patients died in the one-year follow-up (55 in the <2% and 10 in the >2% groups; log-rank test p<0.001). Less patients presented moderate/severe exacerbations in the higher eosinophils group. Similar results were observed using 3% and 150 and 300 cells/μL cut-points. Conclusion: In this prospective study we showed that hospitalized COPD patients with higher blood eosinophils present with lower disease severity on admission and have better outcomes. Our data further support the use of blood eosinophils as a prognostic biomarker for hospitalized COPD patients.
In the present prospective multicentre observational study, we evaluated the potential role of blood eosinophils on the outcomes of patients hospitalized for COPD exacerbations.Consecutive patients >40 years with a previous COPD diagnosis were recruited. Blood eosinophils were measured on admission prior to the initiation of treatment and were evaluated in three groups (<50, 50-149 and ≥150 cells/μL). Patients received standard care and were followed up for a year.A total of 388 patients were included (83.5% male, mean age 72 years). Patients with higher blood eosinophils had less dyspnoea (Borg scale), lower C-reactive protein (CRP) and higher PaO2/FiO2 (partial pressure for oxygen/fraction of inhaled oxygen), and were discharged earlier (median 11 vs. 9 vs. 5 days for patients with <50, 50-149 and ≥150 cells/μL, respectively). Patients with <50 cells/μL presented higher 30-day and 1-year mortality, whereas there were no differences in moderate/severe COPD exacerbations between the three groups. In a post hoc analysis, treatment with inhaled corticosteroids as per physicians' decision was associated with better exacerbation prevention during follow-up in patients with ≥150 cells/μL.Higher blood eosinophils were associated with better outcomes in hospitalized COPD patients, further supporting their use as a prognostic biomarker.
