The aim of the study is to investigate by flow cytometry the phenotype of alveolar macrophages (AMs) isolated from patients with non-infectious lung diseases.

Although alveolar macrophages (AMs) represent the main immune cell population in the human lungs, consensus on their phenotypic characterization is still missing.

Current translational protocols use human AMs obtained by invasive methods (broncho-alveolar lavage and lung biopsy) or differentiate macrophages from blood monocytes cultured in the presence of growth factors such as macrophage colony-stimulating factor (M-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF). The group has already published the phenotypic and functional comparison of human blood monocyte-derived macrophages differentiated with M-CSF or GM-CSF. Aim of this study is to use a multi-staining flow cytometry (FACS analysis) to better characterize the phenotype of AMs isolated from broncho-alveolar lavage fluids of patients affected by non-infectious lung diseases. The FACS profiles of AMs will be further compared to the phenotypic profile of blood monocyte-derived macrophages differentiated in the presence of GM-CSF or M-CSF. The results of this study will allow to define the most valid in vitro model of AMs in a non-infectious setting.

Inclusion Criteria:

• Patients affected by non-infectious lung diseases and for whom a broncho-alveolar lavage is scheduled for their medical care in the pulmonary division
• Patient Information leaflet provided
• Written informed consent of the patient

Exclusion Criteria:

• A suspected respiratory infection

Patients affected by non-infectious lung diseases older than 18 years