Inclusion Criteria:  CAP meets the diagnostic criteria published in 2016 Chinese CAP diagnosis and treatment guidelines; CPOPD and AECOPD meet the diagnostic criteria published in Chinese 2013 COPD diagnosis and treatment guidelines; Age ≧ 40years.  Exclusion Criteria:  age <40years; pregnancy; positive for human immunodeficiency virus (HIV) antibodies; suspected or confirmed tuberculosis or fungal infection of the lung.