Eosinopenia Predicting Long-term Mortality in Hospitalized Acute Exacerbation of COPD Patients with Community-acquired Pneumonia—A Retrospective Analysis

BACKGROUND: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) could be triggered by community-acquired pneumonia (CAP). Peripheral blood eosinopenia are strongly associated with increased mortality. In hospitalized AECOPD patients with CAP, eosinopenia may be used to identify patients with high risk of death on admission. METHODS: We conducted a retrospective cohort study in 82 hospitalized AECOPD patients with CAP. Patients who had received systemic corticosteroids preadmission were excluded. The patients were identified by individual case file review. According to blood eosinophil count, patients were grouped as eosinopenia (<50/μL) and non-eosinopenia (≥50/μL). Association of eosinopenia with infection and 18-month survival were analyzed using appropriate statistical methods. RESULTS: Baseline demographic, comorbidity, CURB65 and Pneumonia Severity Index scores were similar between two groups. The eosinopenia group had significantly higher pro-brain natriuretic peptide, D-dimer, neutrophil percentage, and lower lymphocyte count and lymphocyte percentage. The eosinopenia group had significantly higher C-reactive protein (median 77.30 vs 16.55, p=0.008) and procalcitonin (median 0.32 vs 0.12, p=0.001). Survival at 18 months after hospital discharge was significantly lower in the eosinopenia group vs non-eosinopenia group (log rank, p=0.002). CONCLUSION: Eosinopenia (<50/μL) was a strong predictor of 18-month mortality and associated with more severe infection in hospitalized AECOPD patients with CAP. Eosinophil count at admission can be used as a prognosis marker of mortality in those population.