Controlled Exposure to Diesel Exhaust in Subjects With Allergic Rhinitis

Study Overview
=================
Brief Summary
-----------------
Proximity to traffic, particularly to diesel-powered heavy-duty vehicles, has been associated with inducing and enhancing allergies in children and adults. To investigate the basis for this association, a controlled exposure of allergic rhinitics to diesel exhaust was performed at a dose known to be pro-inflammatory in healthy individuals. The hypothesis was that airway inflammation would be augmented in allergic rhinitics following exposure to diesel exhaust at an environmentally pertinent particulate matter concentration. Fourteen allergic rhinitics were exposed in a double-blinded, randomised trial to both diesel exhaust at 100 microgram/m3 PM10 (representing an aerosol of nanoparticulate combustion particles, mean diameter 80 nm) and filtered air for two hours on separate occasions. Bronchoscopy with endobronchial mucosal biopsies and airway lavage was performed 18 hours post-exposure, and samples were analysed for markers of inflammation.

Official Title
-----------------
Controlled Exposure to Diesel Exhaust in Subjects With Allergic Rhinitis

Conditions
-----------------
Allergic Rhinitis

Intervention / Treatment
-----------------
* Procedure: Bronchoscopy


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: History of seasonal allergic rhinitis requiring medical treatment only during the pollen season and were classified as mild and intermittent according to ARIA guidelines. Positive skin prick test to airborne allergens Normal lung function Negative Metacholine challenge Exclusion Criteria: Current smoking or a previous history of smoking. Asthma Chest infection within six weeks prior to or during the study Current use of non-steroidal anti-inflammatory drugs Current vitamin C or E supplementation Current use of topical nasal steroids.

Ages Eligible for Study
-----------------
Minimum Age: 20 Years
Maximum Age: 45 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Diesel exhaust<br>2 hour exposure to diesel exhaust at 100 microgram per cubic meter during intermittent exercise | Procedure: Bronchoscopy<br>* Bronchoscopy with endobronchial biopsy sampling and bronchoalveolar lavage (BAL) 18 hours post exposure. Airway inflammation was assessed.<br>* Other names: BAL;|
| Experimental: Filtered air exposure<br>2 hour exposure to filtered air during intermittent exercise | Procedure: Bronchoscopy<br>* Bronchoscopy with endobronchial biopsy sampling and bronchoalveolar lavage (BAL) 18 hours post exposure. Airway inflammation was assessed.<br>* Other names: BAL;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Airway inflammation | Bronchoscopy with endobronchial mucosal biopsies and airway lavage was performed 18 hours post-exposure to diesel exhaust and filtered air, and samples were analysed for markers of inflammation. | 18 hours post exposure | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Particulate matter, Air pollution, Diesel exhaust, Allergic rhinitis