Trial record 8 of 30 for:    "Air Pollution" | Open Studies

Air Pollution and Allergens - Attenuation of Health Effects Particle Reduction (DE3)

This study is currently recruiting participants. (see Contacts and Locations)
Verified June 2014 by University of British Columbia
Sponsor:
Information provided by (Responsible Party):
University of British Columbia
ClinicalTrials.gov Identifier:
NCT02017431
First received: December 16, 2013
Last updated: June 19, 2014
Last verified: June 2014
  Purpose

The study probes the effects of combined exposures to diesel exhaust and allergens on lung function and on the immune system, specifically focusing on the ability of a particle depletion technique to attenuate effects we and others have seen previously. Individuals are exposed to either filtered air (FA), carefully controlled levels of diesel exhaust (DE) or particle-depleted diesel exhaust (PDDE) in our exposure chamber, after which the investigators will administer an inhaled allergen challenge. 48h later, a procedure called bronchoscopy is used to collect samples from the lungs. After 1mo, the entire procedure is to be repeated with one of the alternate exposures. This will be repeated 4 times (4 exposures; 2 filtered air, 1 diesel exhaust, 1 particle-depleted diesel exhaust)


Condition Intervention
Allergies
Other: Allergen
Other: Saline
Other: Particle depleted diesel exhaust

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Strengthening the Case for Ongoing Reduction of Exposure to Traffic-Related Air Pollution

Resource links provided by NLM:


Further study details as provided by University of British Columbia:

Primary Outcome Measures:
  • Allergen-specific immunoglobulin [ Time Frame: 48 hours ] [ Designated as safety issue: No ]
    BAL IgE and IgG4 specific to the allergen used for allergen challenge will be assessed at 48 hrs, from the BAL, using immunocap assay.


Secondary Outcome Measures:
  • epithelial cell DNA methylation [ Time Frame: 48 hours ] [ Designated as safety issue: No ]
    Determine if allergen-induced changes in DNA methylation within epithelial cells is augmented by DE (300 µg/m3 inhaled for two hours) and attenuated by PDDE.

  • proteomic signature [ Time Frame: 48 hours ] [ Designated as safety issue: No ]
    Determine if allergen-induced changes in proteomic profile within epithelial cells is augmented by DE (300 µg/m3 inhaled for two hours) and attenuated by PDDE.

  • Airway reactivity [ Time Frame: 48 hours ] [ Designated as safety issue: No ]
    Determine if airway reactivity (measured by PC20 methacholine challenge) is augmented by DE (300 µg/m3 inhaled for two hours) or PDDE exposure.


Estimated Enrollment: 18
Study Start Date: January 2014
Estimated Study Completion Date: January 2015
Estimated Primary Completion Date: January 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Filtered air
Exposure for 2 hours to filtered air followed by subject specific inhaled allergen challenge
Other: Allergen
Subject specific allergen is inhaled on day 1 of the triad
Experimental: Diesel exhaust
Exposure for 2 hours to diesel exhaust followed by subject specific inhaled allergen challenge
Other: Allergen
Subject specific allergen is inhaled on day 1 of the triad
Active Comparator: Filtered air control
Exposure for 2 hours to filtered air followed by inhaled saline challenge
Other: Saline
Saline is inhaled on day 1 of the triad
Experimental: Particle depleted diesel exhaust
Exposure for 2 hours to particle depletion diesel exhaust followed by inhaled allergen challenge
Other: Allergen
Subject specific allergen is inhaled on day 1 of the triad
Other: Particle depleted diesel exhaust
High-efficiency particulate filtration of diesel exhaust

Detailed Description:
  1. Purpose/Objective:

    The aim of this study is to investigate the ability of depletion of diesel exhaust particles to attenuate adverse effects of diesel exhaust on lung function and on allergic responses.

  2. Hypotheses:

    Hypothesis 1: Allergen-specific immune response (specific IgG4, etc; relevant responses in DNA methylation and proteomics) in allergen-challenged airways in sensitized individuals is increased by diesel exhaust.

    Hypothesis 2: Synergistic responses to will be greater in asthmatics than in non-asthmatics.

    Hypotheses 3: Synergy between inhaled DE and common aeroallergens is attributable to the particulate fraction of DE (i.e. is normalized by particle depletion).

  3. Justification:

    Diesel exhaust consists of both gaseous and particulate air pollutants. In recent studies, cardiovascular effects seem attenuated when only the particulate portion is removed. We would like to know if that is true for respiratory and immunological endpoints. Understanding these potentially subtle changes will help us prevent health problems associated with air pollution in the future.

  4. Research Method:

Blinded crossover experiment between four conditions (DE and allergen, PDDE and allergen, FA and allergen, FA and saline), randomized and counter-balanced to order. Each condition will be separated by a 4-week washout period.

An inhaled allergen or saline challenge is delivered after each exposure (DE, PDDE, or FA). 24 h post challenge, airway reactivity will be assessed with a methacholine challenge. 48 h post challenge, bronchoalveolar lavage (BAL), airway brushes and tissue biopsies will be obtained for analysis of immune activation. Nasal lavage samples will also be collected to examine responses in the upper airways and blood and urine will be studied to examine systemic responses. Spirometry and methacholine challenge will be used to assess effects on airway function.

  Eligibility

Ages Eligible for Study:   19 Years to 49 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Age between 19 and 49 years
  • Non-smoking
  • Positive skin prick test for at least one of: birch, grass, or dust

Exclusion Criteria:

  • Using inhaled corticosteroids
  • Pregnant or planning to be pregnant in the next 12 months / Breastfeeding
  • Usage of bronchodilators more than three times per week.
  • Co-morbidities (as assessed by the primary investigator)
  • Taking part in other studies
  • Unwilling to withhold bronchodilator, aspirin, anti-coagulant, antihistamine or decongestant medications or caffeine prior to testing procedures.
  • FEV1(Forced expiratory volume in one second) < 70% predicted.
  • Allergy to lidocaine, fentanyl, midazolam or salbutamol.
  • Unstable asthma (i.e exacerbation in 2 weeks preceding testing)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT02017431

Contacts
Contact: Christopher Carlsten, MD, MPH 604-875-4122 carlsten@mail.ubc.ca

Locations
Canada, British Columbia
University of British Columbia Recruiting
Vancouver, British Columbia, Canada, V5Z 1M9
Contact: Christopher Carlsten, MD, MPH    604-875-4122    carlsten@mail.ubc.ca   
Principal Investigator: Christopher Carlsten, MD, MPH         
Sponsors and Collaborators
University of British Columbia
Investigators
Principal Investigator: Christopher Carlsten, MD, MPH University of British Columbia
  More Information

Publications:
Responsible Party: University of British Columbia
ClinicalTrials.gov Identifier: NCT02017431     History of Changes
Other Study ID Numbers: H11-01831/2013
Study First Received: December 16, 2013
Last Updated: June 19, 2014
Health Authority: Canada: Health Canada

Keywords provided by University of British Columbia:
Diesel exhaust
Particle depleted diesel exhaust
Air pollution
Airway responsiveness
Allergies

ClinicalTrials.gov processed this record on September 16, 2014