Large doses of systemic corticosteroids ，severe lung tissue damage and longer COPD diagnosis may increase the risk of IPA in patients with chronic structural lung disease. By comparing the risk factors of aspergillus colonization group and aspergillus infection group, the main risk factors of aspergillus pneumonia were determined.

Patients with chronic lung disease were identified as positive for Aspergillus fumigatus through sputum microscopy. According to diagnostic criteria, patients diagnosed with IPA and CPA and were assigned to the Aspergillosis pneumonia group, while the remaining patients were included in the Aspergillus colonization group. Then,Risk factors for aspergillus pneumonia, invasive pulmonary aspergillus disease, and chronic pulmonary aspergillus disease, such as the use of high-dose corticosteroids, inhaled corticosteroids, and the extent of damage to basic lung structures, were identified by comparing the aspergillus colonization group with the aspergillus infection group.

Inclusion Criteria:

1. Age : at least 18 years old ;
2. Imageological examination : Patients who complete high-resolution computed tomography (HRCT) images of the chest;
3. Serological examination : Patients who complete serological test results, including serum aspergillus specific IgG antibody, serum aspergillus IgM antibody and GM antigen detection.

Exclusion Criteria:

1. immunodeficiency conditions : Patients diagnosed with HIV infection, hematological malignancies, and autoimmune diseases.
2. Critically ill patients : Those who require mechanical ventilation in the ICU and have established various types of cardiopulmonary bypass.
3. Inadequate Clinical Data: Inability to provide reliable diagnostic measurements or insufficient clinical information.

Non-repeat patients with chronic lung disease were included in the suspected pulmonary aspergillosis study group. According to the current study inclusion criteria, patients were excluded due to unqualified sputum specimens or negative culture results, together with patients lacked HRCT image data. Qualified patients were finally included. According to different group definitions, patients without IPA and CPA were classified into the Aspergillus colonization group and patients with IPA and CPA were included in the aspergillus infection group.