The HOMEOS study is an exploratory, observational, and monocentric research. It focuses on characterizing the homeostatic roles of eosinophils in severe asthma. The primary objective is to identify eosinophil subpopulations among different groups of severe asthmatic patients using flow cytometry. The study aims to advance understanding of eosinophil diversity, which could guide new therapeutic approaches .

Inclusion Criteria:

• Patients diagnosed with mild asthma with severe asthma (Biologic-naïve, responders to anti-eosinophil biologic therapies and resistant to anti-eosinophil biologic therapies), control subjects without asthma
• Signature of informed consent
• Affiliation with the French social security system

Exclusion Criteria:

• Non-eosinophilic asthma
• Coexistence of a chronic eosinophilic inflammatory condition other than asthma
• Other respiratory conditions (cystic fibrosis, COPD, allergic bronchopulmonary aspergillosis, etc.)
• Treatment with corticosteroids within 10 days prior to inclusion
• Active smoking or a smoking history of more than 20 pack-years
• Pregnant women
• Legal incapacity or limited legal capacity
• Subject unlikely to cooperate with the study and/or with anticipated low cooperation as assessed by the investigator
• Subject without health insurance
• Subject currently in an exclusion period of another study or as indicated by the "national registry of volunteers."