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

Study Overview
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Brief Summary
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The purpose of this study is to study differences in small airways (<2mm) parameters in asthma patients, subjects with asymptomatic airway hyperresponsiveness and healthy controls.

Official Title
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Differences in Small Airways Disease Between Asymptomatic and Symptomatic Subjects With Airway Hyperresponsiveness

Conditions
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Asthma, Airway Hyperresponsiveness

Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Asthma<br>asthmatic subjects | |
| Asymptomatic AHR<br>Asymptomatic subjects with airway hyperresponsiveness | |
| Control<br>Healthy controls, without airway hyperresponsiveness | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peripheral airway resistance measured with impulse oscillometry (IOS) | Difference between resistance at 5 Hz (R5) and resistance at 20 Hz (R20) (R5-20). | visit 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Small airway parameters | Forced expiratory flow between 25 and 75% of forced vital capacity (FEF25-75), alveolar nitric oxide (NO), residual volume (RV), RV/total lung capacity (TLC) | visit 1 | 
| mRNA expression in nasal epithelium |  | visit 2 | 
| Peripheral airway resistance measured during provocation test | Resistance at 5 Hz (R5) during a bronchial provocation test with methacholine | visit 2 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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asthma, airway hyperresponsiveness, asymptomatic airway hyperresponsiveness, small airways