RATIONALE:

In asthmatic subjects, smoking can lead to several changes in disease characterictics. in smokers of more than 20 pack-years, chronic obstructive pulmonary disease (COPD) can be associated with asthma, also called asthma-COPD overlap syndrome (ACOS). Increasing data support the concept that ACOS is a clinical entity. However, this should be further studied in order to better target therapy.

AIM:

The objective of this study is to evaluate the comparative features of ACOS

METHODS:

This will be a descriptive study comparing the features of the ACOS with the features of asthmatic subjects with an incomplete reversibility of airway obstruction (IRAO).The study will be done over 1 or 2 visits (within a week interval), according to subjects' availability. The visit will include completion of different questionnaires (asthma control asthma quality of life, medical history, exacerbations, etc.), a thoracic examination, allergy skin-prick tests, spirometry and bronchodilator response, lung volumes and compliance measurements, exhaled nitric oxide measurement, blood sampling and a sputum induction.

Inclusion Criteria:

ALL SUBJECTS

1. Subjects aged 45 years and older.
2. Free of any other respiratory condition, except for asthma and/or COPD, which may interfere with the tests.
3. Asthma that requires a baseline treatment with inhaled corticosteroids and/or additional asthma medication.
4. Free of respiratory infection in the 4 weeks preceding the study.
5. No changes in the asthma and COPD-related medications in the 4 weeks preceding the study.
6. If female, not pregnant (or lactating).
7. Able to adhere to study procedures.
8. Able and willing to provide written informed consent to participate in the study, in accordance with international conference on harmonization (ICH) good clinical practice (GCP) requirements.

ACOS SUBJECTS

1. Smokers or ex-smokers of at least 20 pack-years. 2. With an IRAO (see definitions section). IRAO SUBJECTS

1. Long-life non-smokers or ex-smokers defined as someone who smoked less than 5 pack-years and who completely stopped smoking for at least 12 months before inclusion in the study.
2. With an IRAO.

Exclusion Criteria:

• ALL SUBJECTS

  1. With COPD without a past diagnosis of asthma.
  2. Unstable respiratory or non-respiratory condition.
  3. Any active chronic inflammatory disease.
  4. Any evidence of malignancy (active and/or treated) within the previous 5 years.
  5. Any significant concomitant illness or injury that would interfere with the subject's participation in the study.
  6. Any history of bronchial thermoplasty. IRAO SUBJECTS
  1. Use of any nicotine containing product within 1 year prior to study entry or a smoking history of > 5 pack-years.

Asthmatic subjects will be recruited from the asthma outpatient clinic, from participation to past research studies, or from advertisements.