The Prognostic Value of Blood Eosinophil Level in AECOPD is Influenced by Corticosteroid Treatment During Hospitalization

Abstract

Purpose

Blood eosinophil is a promising biomarker for phenotyping patients with acute exacerbation of COPD (AECOPD). We aimed to evaluate the prognostic value of eosinophil on short- and long-term outcomes stratified by corticosteroid treatment among AECOPD inpatients.

Patients and Methods

In this retrospective cohort study, we included patients hospitalized for AECOPD from July 2013 to June 2021 in Beijing, China. Clinical data were collected from electronic medical records. The blood eosinophil count was measured within 24h after admission. Eosinophilic AECOPD was defined as having an eosinophil percentage ≥ 2%. The study outcomes were length of stay (LOS), treatment failure, and AECOPD readmission risk within 3 years of discharge. Multivariable models were used to analyze the associations between blood eosinophil count and outcomes stratified by corticosteroid treatment during hospitalization.

Results

A total of 2406 AECOPD patients were included. The median LOS of AECOPD patients was 10 (interquartile range: 8–14) days. The eosinophil percentage was negatively associated with LOS (P-trend=0.014). Compared with the non-eosinophilic AECOPD group, the eosinophilic group had a 58% lower risk of treatment failure (OR=0.42, 95% CI: 0.20–0.89) in patients treated with systemic corticosteroids, but no association was observed in those treated with inhaled corticosteroids (ICS) only (OR=0.95, 95% CI: 0.60–1.52). The eosinophilic group had an increased risk of 90-day re-admission in patients treated with ICS only (HR=1.51, 95% CI: 1.00–2.29), but not in patients treated with systemic corticosteroids during hospitalization (HR=0.67, 95% CI: 0.39–1.15). No statistically significant results were found for 180-day, 1-year, or 3-year readmission risk.

Conclusion

Elevated blood eosinophils in AECOPD were associated with shorter length of stay and improved response to treatment with systemic corticosteroids, but not inhaled corticosteroids. Our study suggested that a therapeutic approach of using systemic corticosteroid may benefit patients present with eosinophilic AECOPD.

Keywords:

• chronic obstructive pulmonary disease
• eosinophilic inflammation
• glucocorticoids
• interaction

Data Sharing Statement

The datasets used during the current study are available from the corresponding author on reasonable request.

Ethics Approval and Informed Consent

This study was approved by the Research Ethics Board of Beijing Chaoyang Hospital (2020-ke-511). Informed consent was waived by the Research Ethics Board of Beijing Chaoyang Hospital (2020-ke-511) due to the retrospective nature of the study. Patient data was anonymized before analysis. All methods were carried out in accordance with the Declaration of Helsinki.

Disclosure

Professor Christopher E Brightling reports grants, personal fees from GSK, AZ, Chiesi, BI, Sanofi, Regeneron, Genentech, Roche, Mologic, Novartis, Areteia, outside the submitted work. The authors report no other conflicts of interest in this work.

Additional information

Funding

This work was supported by grants from the Beijing Municipal Science & Technology Commission (No. Z201100005520028, Z201100005520029), Beijing Key Specialists in Major Epidemic Prevention and Control, Financial Budgeting Project of Beijing Institute of Respiratory Medicine (Ysbz2023002), and Clinical Research Incubation Project, Beijing Chao-Yang Hospital, Capital Medical University (CYFH202210). The funder had no role in the study design, data collection, data analysis and interpretation, writing of the report, or the decision to submit the article for publication.