The Study of Differences in Eosinophil Function and Subsets in Patients With Eosinophilic Pulmonary Diseases

Inclusion Criteria: * For Healthy Volunteers: healthy volunteers matching the age and gender of the study subjects * For EPD: ① Persistent eosinophil count increase\>1500 per cubic millimeter for more than 6 months. ② Lack of evidence of a secondary cause of eosinophilia is required. ③ Signs and symptoms of end-organ damage presumed to be secondary to eosinophilia Exclusion Criteria: * Patients with concurrent definitive pulmonary infections, malignancies, or other parenchymal lung diseases; * Patients who are unable or unwilling to cooperate with the collection of clinical information (e.g., due to mental disorders, memory impairments, etc.); * Patients who are unable to provide informed consent.