Eosinopenia as a Marker of Outcome in Acute Exacerbations of Chronic Obstructive Pulmonary Disease.

Background: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a common cause of hospitalization and mortality. Recent studies have shown the usefulness of eosinopenia in predicting the outcomes of patients admitted to the intensive care unit. This study examined the association of eosinopenia with the outcomes of patients with AECOPD.

Methods: This is a prospective study. Patients with AECOPD were divided into two cohorts: patients with eosinopenia and those without eosinopenia. Duration of hospitalization, need of mechanical ventilation, in-hospital mortality, rehospitalization, or death within 30 days after discharge were compared between the two cohorts. Eosinopenia was defined as eosinophil count of >40 cells/mm(3).

Results: Among 100 patients with AECOPD, 44 were eosinopenic and 56 were non-eosinopenic. Duration of hospitalization of patients with eosinopenia was 12.38 ± 9.85 days and that of patients without eosinopenia was 7.35 ± 5.68 days (p = 0.001). In all, 16 (36%) patients with eosinopenia and seven (12%) patients without eosinopenia needed mechanical ventilation (p = 0.005). In-hospital mortality rate among eosinopenic and noneosinopenic patients was 37.5% (12/44) and 7.6% (4/56), respectively (p = 0.006). Among 100 patients with AECOPD, 16 died in the hospital. Of these, 12 (27.27%) were eosinopenic and 4 (7.6%) were noneosinopenic (p = 0.006). The mean eosinophil count of patients who died in the hospital (n = 16) was 44.00 cells/ml whereas that of survivors (n = 84) was 107.41 cells/ml (p = 0.022).

Conclusion: We conclude that a significant relationship exists between eosinopenia and outcomes of patients with AECOPD. Thus, eosinopenia can be a useful, easy-to-measure, and inexpensive biomarker for predicting the prognosis of patients with AECOPD.