Difficulty in recruiting subjects

Chronic Obstructive Pulmonary Disease (COPD) is one of the top three causes of death worldwide now. Acute exacerbations (AEs) of COPD are a risk factor for lung function deterioration, poor quality of life, longer hospitalization, and increased mortality. To date, COPD is associated with a heavy clinical and socioeconomic burden, of which AEs of COPD account for a significant part of the cost of patients with COPD. Although several retrospective cohort studies and post-hoc analyses from randomized controlled trials (RCTs) showed that AECOPD patients with higher blood eosinophils had a shorter length of hospital stay (LOS), lower doses of corticosteroid use, and better response to systematic corticosteroid treatment than those with lower blood eosinophils, the efficacy of systematic corticosteroids in AECOPD patients with higher blood eosinophils has not been confirmed by RCTs. Therefore, this study aims to evaluate if AECOPD patients admitted to hospitals with higher blood eosinophil levels could benefit from systemic corticosteroid therapy. In this study, all eligible AECOPD participants with peripheral blood eosinophil blood count >2% or > 300 cells/μL will be randomly assigned (1:1) to either a control group or a systemic corticosteroid group. The control group will receive an oral placebo of 40mg/day for five consecutive days in addition to standard treatment during emergency admission or hospitalization. And systemic corticosteroid group will receive oral prednisone 40mg/day for five consecutive days and standard treatment. This study will provide evidence on using peripheral blood eosinophil blood count to guide corticosteroid therapy in AECOPD patients and help the clinician make an individual decision for each patient.

Data about individual deidentified participants of this trial will be available from the corresponding author Zhaohui Tong (Email: tongzhaohuicy@sina.com) on reasonable request after the main results of the ECHO study have been published.

Inclusion Criteria:

1. Within 24 hours of admission;
2. Aged between of 40 and 80 years old;
3. Established clinical history of COPD with spirometry-verified COPD (defined as post-bronchodilator forced expiratory volume in one second (FEV1)/ forced vital capacity (FVC) ≤ 0.70);
4. AECOPD diagnosis in accordance with the GOLD guideline (An acute worsening of respiratory symptoms that result in additional therapy)12;
5. Current or former cigarette smokers (≥10 packs per year);
6. Blood eosinophil count > 2% or >300 cells/μL tested within 24 hours of admission;
7. Signed informed consent.

Exclusion Criteria:

1. Admission due to other diseases (pneumonia, pneumothorax, pulmonary interstitial disease, active tuberculosis or bronchiectasis, ect);
2. Regular use of glucocorticoid ≥3 months;
3. Received prednisone ≥ 60 mg in the past three days (or equivalent doses of other corticosteroid);
4. Allergic or intolerant to corticosteroid;
5. Participating in or completed another drug trial within 90 days;
6. Pregnancy or lactation;
7. Severe COPD exacerbation requiring invasive mechanical ventilation (IMV) or transfer to ICU within 24 hours after emergency admission or hospitalization;
8. With complications that may cause eosinophilia;
9. Pulmonary embolism within the past two years;
10. Myocardial infarction, uncontrollable congestive heart failure or arrhythmia within the past four weeks;
11. Comorbidity that may influence the immune system;
12. Malignant tumor;
13. Neuromuscular disease affecting the respiratory system;
14. Systemic fungal infection;
15. Thoracotomy or bronchoscopic lung volume reduction surgery history;
16. Adrenocortical insufficiency history;
17. Diabetes mellitus with poor glycemic control;
18. Uncontrollable severe psychiatric illnesses even with medication, cognitive impairment, and severe language difficulties;
19. ALT ≥ 100U/L or AST ≥ 80U/L;
20. Serum creatinine ≥ 162umol/L;
21. Life expectancy of less than 30 days.

Data about individual deidentified participants of this trial will be available from the corresponding author Zhaohui Tong (Email: tongzhaohuicy@sina.com) on reasonable request after the main results of the ECHO study have been published

After the main results of the ECHO study have been published

Supporting information will be available from the corresponding author Zhaohui Tong (Email: tongzhaohuicy@sina.com)