MxA and CRP-Guided Use of Antimicrobial Agents for AECOPD

Inclusion Criteria: * ≥40 years old； * Current or former smoker with a minimum smoking history of 10 pack years, clinical diagnosed with mild-to-severe COPD; * Presenting with an acute exacerbation of COPD * The severity of AECOPD is mild to moderate. Exclusion Criteria: * Required urgent hospitalization * Received interferon therapy within 30 days before screening * Had an active systemic inflammatory condition within 30 days prior to screening, such as cerebral infarction, myocardial infarction, or surgery * Received vaccine in the past 30 days * Active tuberculosis * Immunocompromised * Presenting with current respiratory failure * Clinical suspicion of pneumonia or pulmonary edema. * Coexisting bronchiectasis, cystic fibrosis, or asthma * Had a concurrent infection at another site, such as urinary tract infections or sinusitis; * Contraindications to antibiotics and/or antivirals * Known etiology of the present exacerbation * Pre-treatment with corticosteroids (cumulative dose of methylprednisolone ≥ 80 mg or equivalent dose) for the present exacerbation.