Inflammatory Cellular Trafficking in Asthma in Response to Segmental Allergen Challenge
Benjamin Medoff
Summary
Asthma is a heterogeneous disorder in which multiple potential inflammatory pathways contribute to airway obstruction. The biological basis for airway inflammation is the subject of intensive investigation. This work is designed to identify airway factors that are responsible for recruiting cells and associate their airway presence with atopy and asthma.
Description
The production of chemotactic cytokines or chemokines by the airways is one of the mechanisms thought to be responsible for the recruitment of inflammatory cells to the airways (Makay 2001). While the chemokine receptor-ligand systems responsible for immune cell homing to the mucosal surface of the gastrointestinal tract have been clarified, those responsible for allergic airway inflammation remain unknown. This work is designed to identify airway factors that are responsible for recruiting cells and associate their airway presence with atopy and asthma.
Eligibility
- Age range
- 18–50 years
- Sex
- All
- Healthy volunteers
- Yes
A. Subjects with Allergic Asthma (AA subjects) Inclusion Criteria: 1. All subjects will have a baseline FEV1 determined at the characterization visit that is no less than 75 % of the predicted value. 2. All subjects will have a clinical history of allergic symptoms to cat or dust mite allergen and demonstrated skin reactivity (a positive allergen prick test). 3. Life-long absence of cigarette smoking (defined as a lifetime total of less than 5 pack-years); none in 5 years). 4. Willing and able to give informed consent. 5. Expressed the desire to participate in an interview with the principal…
Interventions
- BiologicalBronchoscopy, Segmental Allergen Challenge, and Broncheoalveolar Lavage
Bronchoalveolar lavage is performed in the lingula without instillation of diluent or allergen. A 2ml aliquot of diluent is instilled into the right upper lobe. The procedure is repeated in the right middle lobe with instillation of 2ml of Cat or Mite allergen. A test dose of allergen is administered first. This will consist of 2ml allergen at 1/10th the threshold concentration for Cat or DF Mite Allergen or at 1/30th the threshold concentration for DP Mite Allergen. If on visual inspection through the bronchoscope there is no evidence of reaction to the test dose, a 2nd allergen challenge is done in the right middle lobe using 2ml of full-dose allergen. After a 1,6, or 24hr recovery period, a single 2nd bronchoscopy is performed after delivery of allergen extract and diluent and 1 Tbsp of blood is obtained. Bronchoalveolar lavage will be obtained from the lobes in which the diluent and allergen were instilled. OFDI and endobronchial brushing of the airways will also be performed.
Location
- Massachusetts General HospitalBoston, Massachusetts