Small Airways Disease in Asymptomatic and Symptomatic Subjects With Airway Hyperresponsiveness (AHR)

Inclusion criteria

for asymptomatic subjects with airway hyperresponsiveness (AHR) :

• Age between 18 and 65 years.
• Forced expiratory volume in one second (FEV1) > 80% predicted post bronchodilator.
• Provocative concentration causing a 205 fall in FEV1 (PC20) methacholine <8 mg/ml.
• No history of asthma or previous use of asthma medication.

Inclusion criteria

for asymptomatic subjects without AHR :

• Age between 18 and 65 years.
• FEV1 > 80% predicted post bronchodilator.
• PC20 methacholine >8 mg/ml.
• No history of asthma or previous use of asthma medication.

Inclusion criteria

for patients with asthma:

• Age between 18 and 65 years.
• FEV1 > 80% predicted.
• PC20 methacholine ≤8 mg/ml.
• Doctor's diagnosis of asthma.
• No history of Chronic obstructive pulmonary disease (COPD).

Exclusion criteria

• Use of inhaled or oral steroids, antihistamines, nedocromil, theophylline, leukotrien antagonists or long-acting beta-agonists for at least three weeks before the start of the study.
• Any disease that may affect the outcome of the study as judged by the Investigator.
• FEV1 <1.2 liter.