Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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COMPLETED
NA
18 participants
INTERVENTIONAL
2011-10-31
2013-11-30
Brief Summary
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Detailed Description
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To study the effects of diesel exhaust particles on lung function and on allergic responses.
2. Hypotheses:
Hypothesis 1: DE exposure augments systemic oxidative stress from allergen challenge in allergen-sensitized individuals.
Hypothesis 2: DE exposure augments allergen-specific immune response in allergen-challenged airways in sensitized individuals. These responses will be greater in asthmatic individuals than in non-asthmatics.
3. Justification:
The use of diesel engines is increasing because they are more fuel-efficient than gasoline engines. However, diesel engines produce different emissions than gasoline engines. Diesel exhaust is emitted from the tailpipe of both "on-road" diesel engine vehicles (diesel cars, buses and trucks) and "non-road" diesel engines (locomotives, marine vessels and some construction equipment). Diesel exhaust consists of both gaseous and particulate air pollutants. Since people with asthma and allergic diseases appear to be sensitive to air pollution, we would like to know how diesel exhaust (DE) can affects your respiratory and immune systems. We are expecting that any responses that may occur will only be detectable through careful examination of cells and tissues (e.g., bronchoalveolar lavage (fluid from your lungs), blood, urine). Understanding these potentially subtle changes will help us prevent health problems associated with air pollution in the future.
4. Research Method:
This is a blinded crossover experiment between two conditions (DE or filtered air, FA), randomized and counter-balanced to order. Data collection for each condition will be separated by a 4-week washout period.
Following each exposure, The investigators will use bronchoscopy (performed at the Vancouver General Hospital Endoscopy Suite) to deliver a diluent-controlled segmental allergen challenge (SAC). 24 h post-SAC, airway reactivity will be assessed with a methacholine challenge. 48 h post-SAC, bronchoalveolar lavage (BAL), airway brushes and tissue biopsies will be obtained in the same regions 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
Conditions
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Study Design
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RANDOMIZED
CROSSOVER
BASIC_SCIENCE
TRIPLE
Study Groups
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Filtered air
Exposure for 2 hours to filtered air followed by subject specific allergen placed in lung
Allergen
Subject specific allergen is placed in the lungs on day 1 of each triad
Diesel exhaust
Exposure for 2 hours to diesel exhaust followed by subject specific allergen placed in lung
Allergen
Subject specific allergen is placed in the lungs on day 1 of each triad
Filtered air control
Exposure for 2 hours to filtered air followed by subject saline placed in lung
Saline
Saline will be placed in the lung on day 1 of each triad
Diesel exhaust control
Exposure for 2 hours to diesel exhaust followed by saline placed in lung
Saline
Saline will be placed in the lung on day 1 of each triad
Interventions
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Allergen
Subject specific allergen is placed in the lungs on day 1 of each triad
Saline
Saline will be placed in the lung on day 1 of each triad
Eligibility Criteria
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Inclusion Criteria
2. Non-smoking.
3. Positive skin prick test for at least one of: birch, grass, or dust
Exclusion Criteria
2. Pregnant or planning to be pregnant in the next 12 months / Breastfeeding
3. Usage of bronchodilators more than three times per week.
4. Co-morbidities (as assessed by the primary investigator)
5. Taking part in other studies
6. Unwilling to withhold bronchodilator, aspirin, anti-coagulant, antihistamine or decongestant medications or caffeine prior to testing procedures.
7. FEV1(Forced expiratory volume in one second) \< 70% predicted.
8. Allergy to lidocaine, fentanyl, midazolam or salbutamol.
9. Unstable asthma (i.e exacerbation in 2 weeks preceding testing)
19 Years
49 Years
ALL
Yes
Sponsors
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University of British Columbia
OTHER
Responsible Party
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Christopher Carlsten
Principal Investigator
Principal Investigators
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Christopher Carlsten, MD, MPH
Role: PRINCIPAL_INVESTIGATOR
University of British Columbia
Locations
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University of British Columbia
Vancouver, British Columbia, Canada
Countries
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References
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Saxon A, Diaz-Sanchez D. Air pollution and allergy: you are what you breathe. Nat Immunol. 2005 Mar;6(3):223-6. doi: 10.1038/ni0305-223. No abstract available.
Rudell B, Ledin MC, Hammarstrom U, Stjernberg N, Lundback B, Sandstrom T. Effects on symptoms and lung function in humans experimentally exposed to diesel exhaust. Occup Environ Med. 1996 Oct;53(10):658-62. doi: 10.1136/oem.53.10.658.
Diaz-Sanchez D, Tsien A, Fleming J, Saxon A. Combined diesel exhaust particulate and ragweed allergen challenge markedly enhances human in vivo nasal ragweed-specific IgE and skews cytokine production to a T helper cell 2-type pattern. J Immunol. 1997 Mar 1;158(5):2406-13.
Fujieda S, Diaz-Sanchez D, Saxon A. Combined nasal challenge with diesel exhaust particles and allergen induces In vivo IgE isotype switching. Am J Respir Cell Mol Biol. 1998 Sep;19(3):507-12. doi: 10.1165/ajrcmb.19.3.3143.
Hashimoto K, Ishii Y, Uchida Y, Kimura T, Masuyama K, Morishima Y, Hirano K, Nomura A, Sakamoto T, Takano H, Sagai M, Sekizawa K. Exposure to diesel exhaust exacerbates allergen-induced airway responses in guinea pigs. Am J Respir Crit Care Med. 2001 Nov 15;164(10 Pt 1):1957-63. doi: 10.1164/ajrccm.164.10.2011070.
Carlsten, C., et al., Symptoms and perceptions in response to a controlled diesel exhaust exposure in healthy adults. Environmental Research, In Review
Riedl MA, Diaz-Sanchez D, Linn WS, Gong H Jr, Clark KW, Effros RM, Miller JW, Cocker DR, Berhane KT; HEI Health Review Committee. Allergic inflammation in the human lower respiratory tract affected by exposure to diesel exhaust. Res Rep Health Eff Inst. 2012 Feb;(165):5-43; discussion 45-64.
Carlsten C, Melen E. Air pollution, genetics, and allergy: an update. Curr Opin Allergy Clin Immunol. 2012 Oct;12(5):455-60. doi: 10.1097/ACI.0b013e328357cc55.
Kramer MM, Hirota JA, Sood A, Teschke K, Carlsten C. Airway and serum adipokines after allergen and diesel exposure in a controlled human crossover study of atopic adults. Transl Res. 2017 Apr;182:49-60. doi: 10.1016/j.trsl.2016.11.001. Epub 2016 Nov 9.
Hosseini A, Hirota JA, Hackett TL, McNagny KM, Wilson SJ, Carlsten C. Morphometric analysis of inflammation in bronchial biopsies following exposure to inhaled diesel exhaust and allergen challenge in atopic subjects. Part Fibre Toxicol. 2016 Jan 13;13:2. doi: 10.1186/s12989-016-0114-z.
Carlsten C, Blomberg A, Pui M, Sandstrom T, Wong SW, Alexis N, Hirota J. Diesel exhaust augments allergen-induced lower airway inflammation in allergic individuals: a controlled human exposure study. Thorax. 2016 Jan;71(1):35-44. doi: 10.1136/thoraxjnl-2015-207399. Epub 2015 Nov 16.
Other Identifiers
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H11-01831
Identifier Type: -
Identifier Source: org_study_id