Blood eosinophils: a biomarker of response to glucocorticoids and increased readmissions in severe hospitalized exacerbations of COPD

Abstract

Objective: To compare the clinical characteristics of patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) by different levels of blood eosinophil (EOS) count and to investigate the predictive value of the response to glucocorticoid treatment and the readmission rate in the patients with higher blood eosinophils. Methods: A total of 120 patients with AECOPD were admitted to the Department of Pulmonary and Critical Care Medicine in The Second Xiangya Hospital of Central South University from January 01, 2017 to December 31, 2017. Patients were divided into two groups according to their admission blood eosinophil fractions. Patients with EOS%≥2% were in the EOS group (n=56) , while patients with EOS%<2% were in the Non-EOS group (n=64) . The clinical characteristics, hospitalization treatments especially the glucocorticoid treatment response were compared, and the risk of severe acute exacerbation of the two groups including the 12-month COPD-related readmission, and time to first COPD-related readmission were also compared. Results: Compared with the Non-EOS group, the EOS group had lower values of white blood cell (WBC) , neutrophil fraction (N%) , blood neutrophil-to-lymphocyte ratio (NLR) , and C-reactive protein (CRP) . The EOS group also required shorter course of antibiotic treatment [8 (6-10) and 9 (7-11) , P=0.033]. In glucocorticoid-treated patients (n=82) , the EOS group had significantly alleviated symptoms than the Non-EOS group (patients withδCAT≥2 were 86.8% and 68.2%, respectively, P=0.046) , and the duration of hospitalization of the EOS group was shorter [9 (7-11) and 10 (9 to 13) , P=0.042]. Patients with glucocorticoid treatment in the EOS group had significantly alleviated symptoms than those without glucocorticoid treatment (patients with δCAT ≥ 2 were 86.8% and 61.1%, respectively, P=0.040) . The follow-up one year after discharge showed a higher risk of severe acute exacerbation in the EOS group [Adjust OR 2.67 (1.10-6.46), P=0.030; HR: 1.57 (1.02-2.40), P=0.040]. Conclusion: The blood eosinophil levels were useful in predicting the AECOPD patients' response to glucocorticoid treatment and the risk of severe acute exacerbations.