Inclusions was stopped at 30 patients. Investigators did not wish to extend inclusions.

This is a prospective study comparing 4 groups: (1) non-smoking controls, (2) smokers without chronic obstructive pulmonary disease (COPD), (3) smokers with COPD, (4) severe asthma.

Bronchial biopsy specimens from each subject will be obtained to produce air-liquid-interface cell cultures. These will then be used to make observations concerning cilia and mucus rheology.

This is a first pilot study. The working hypothesis is that the largest group differences will be found for cilia densities; the latter metric was thus chosen as a primary criterion.

Inclusion criteria for non smoking controls:

• The subject has given free and informed consent and signed the consent form
• The subject is affiliated with or beneficiary of a medical insurance program
• The subject has never smoked
• No obstructive breathing disorder (forced expiratory volume at one second (FEV1) >70% of predicted value; the ratio of FEV1 to forced vital capacity (FEV1/FVC) is > 0.7)
• No known respiratory disease

Inclusion criteria for smokers without COPD:

• The subject has given free and informed consent and signed the consent form
• The subject is affiliated with or beneficiary of a medical insurance program
• Smoker or former smoker (>= 30 pack years)
• No obstructive breathing disorder (forced expiratory volume at one second (FEV1) >70% of predicted value; the ratio of FEV1 to forced vital capacity (FEV1/FVC) is > 0.7)

Inclusion criteria for smokers with COPD:

• The subject has given free and informed consent and signed the consent form
• The subject is affiliated with or beneficiary of a medical insurance program
• Smoker or former smoker (>= 30 pack years)
• Subject presenting with COPD: FEV1/FVC < 0.7 (based on spirometry values in the medical file and performed in the 3 months prior to inclusion)
• The subject requires bronchial fibroscopy (decision made by pneumologist)
• COPD of grade "2" or "3" according to GOLD criteria (Global Initiative for Chronic Obstructive Lung Disease)

Inclusion criteria for subjects with severe asthma:

• The subject has given free and informed consent and signed the consent form
• The subject is affiliated with or beneficiary of a medical insurance program
• Non-smoker or former smoker (<10 pack years)
• Subject presenting with severe asthma: FEV1/FVC >= 0.7 and FEV1 < 80%
• The subjects requires bronchial fibroscopy (decision made by pneumologist)

Exclusion criteria:

• The subject has an extensive neoplastic disease
• The subject has another active lung disease (tuberculosis, pulmonary interstitium disease, active or recent pulmonary infection)
• The subject has had a recent psychiatric disorder (within one year prior to inclusion and documented by a specialist consultation)
• Emergency situations (object extractions...)
• Subject consuming illicit drugs or alcohol
• The subject is in an exclusion period determined by a previous study
• The subject is under judicial protection, or is an adult under any kind of guardianship
• It is impossible to correctly inform the patient
• The subject cannot fluently read French