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Completed

NCT Number: NCT00625989

The Effect of Allergen Inhalation on Sputum Myeloid and Plasmacytoid Dendritic Cells in Mild Atopic Asthmatics

Summary:

A picture is emerging of dendritic cells migrating through the blood to the airways following allergen inhalation in atopic asthmatics. Although the Koh and McCarthy articles present novel findings, both do not provide a comprehensive view of sputum DCs following allergen challenge. Therefore, the proposed study will examine the kinetics of mDCs and pDCs in the induced sputum of atopic asthmatics following inhalation of allergen.

Hypothesis:

Following allergen challenge, sputum myeloid and plasmacytoid DCs will migrate into the airway lumen in atopic asthmatics during the timeframe of the late asthmatic response.

Objective:

The objective of this study is to examine the kinetics of dendritic cells in induced sputum following allergen challenge in atopic asthmatic subjects.

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Key information

Conditions

Asthma Bronchial Diseases Hypersensitivity Hypersensitivity, Immediate Immune System Diseases Lung Diseases Lung Diseases, Obstructive Respiratory Hypersensitivity Respiratory Tract Diseases

Age range

18 year–65 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

McMaster University

Hamilton, Ontario, L8N 3Z5, Canada

About this study

Subjects will be put through two study periods. Each study period will consist of four visits and will be separated by 2-4 weeks. On the first visit, subjects will undergo screening procedures, including complete history and physical examination. In addition, methacholine inhalation challenge and skin-prick testing will be preformed to assess airway hyper-responsiveness and determine atopic status respectively. Lastly, sputum will be induced before challenge (0 hrs) and peripheral blood will be collected. On the second visit, subjects will inhale diluent or allergen and sputum will be collected 7 hours following inhalation challenge. Next, on the third visit, subjects will return 24 hours following inhalation challenge and sputum will be induced. On the final visit, subjects will return 72 hours following inhalation challenge and sputum will be collected, along with peripheral blood.

Before the next study period begins, there will be a washout period of 2-4 weeks. On the first visit of the second study period, a methacholine challenge will be performed to ensure the return of PC20 to within one doubling dose of baseline values. Also, sputum will be induced before challenge (0hrs) and peripheral blood will be collected. On the second visit, subjects will inhale diluent or allergen and sputum will be collected 7hrs following inhalation challenge. Next, on the third visit, subjects will return 24 hours following inhalation challenge and sputum will be induced. On the final visit, subjects will return 72 hours following inhalation challenge and sputum will be collected, along with peripheral blood.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Mild atopic asthmatics, presently well controlled on ß2-agonists.
  • Non-smokers.
  • Baseline FEV1 more than 70% of predicted normal.

Exclusion criteria

  • Airway infection during the last 4 weeks.
  • Exacerbation during the last 4 weeks.
  • Inhaled or oral steroids during the last 4 weeks.
  • Antihistamines during the last 48 hours.
  • Asthma medication other than inhaled and/or oral ß2-agonists during the last 4 weeks.
  • Pregnant women.

Treatment and study plan

Aeroallergen

Drug

Primary outcomes

  1. The Primary Outcome Measure for This Study is the Number of Sputum Myeloid Dendritic Cells

    Time frame: 24 hrs

    Flow-cytometric acquisitions were used to determine the percentage of each type of mononuclear cell. These percentages were multiplied by the number of sputum mononuclear cells calculated by using total and differential cell counts of the sputum sample.

  2. The Primary Outcome Measure for This Study is the Number of Sputum Plasmacytoid Dendritic Cells

    Time frame: 24 hrs

    Flow-cytometric acquisitions were used to determine the percentage of each type of mononuclear cell. These percentages were multiplied by the number of sputum mononuclear cells calculated by using total and differential cell counts of the sputum sample.

Secondary outcomes

  1. The Secondary Outcome Measure is the Level of Specific Chemokines Released in the Sputum Supernatant.

    Time frame: Before inhalation (0hrs)

  2. The Secondary Outcome Measure is the Level of Specific Chemokines Released in the Sputum Supernatant

    Time frame: 7 hrs

  3. The Secondary Outcome Measure is the Level of Specific Chemokines Released in the Sputum Supernatant

    Time frame: 24 hrs

  4. The Secondary Outcome Measure is the Level of Specific Chemokines Released in the Sputum Supernatant

    Time frame: 72 hrs

Sponsors and collaborators

Lead sponsor

Hamilton Health Sciences Corporation

Other

Registry information

Important dates

Study start
2008
Primary completion
2008
Study completion
2008
First posted
Feb 29, 2008
Registry last updated
May 21, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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