Study of the Involvement of IL-17 / IL-22 Pathway in Bacterial Exacerbations of COPD

This study is looking at how a specific immune system pathway (involving proteins called IL-17 and IL-22) may contribute to bacterial infections that cause flare-ups (exacerbations) in patients with COPD (chronic obstructive pulmonary disease — a long-term lung condition that makes breathing difficult, often caused by smoking). **You may be eligible if...** - You have been diagnosed with COPD according to standard medical guidelines - You are a current or former smoker with at least 10 pack-years of smoking history (e.g., one pack per day for 10 years, or equivalent) - You are currently hospitalized due to a COPD exacerbation (a sudden worsening of your breathing symptoms) **You may NOT be eligible if...** - You have asthma or cystic fibrosis - You have another chronic lung disease that could confuse the results - You have an active or recently treated cancer that has not gone into remission - You currently use inhaled recreational drugs - You are a woman of childbearing age without effective contraception - You are pregnant or breastfeeding - You lack the legal or mental capacity to give informed consent - You do not have social security coverage (required for this study site) Talk to your doctor to see if this trial is right for you.