The role of indoleamine 2,3-dioxygenase in virus-induced asthma exacerbations

Conditions: asthma
virus-induced asthma exacerbation
10001708
10006436
10047438

Registration Number: NL-OMON33934

Lead Sponsor: Academisch Medisch Centrum

Brief Summary: Not available

Detailed Description: Not available

Recruitment & Eligibility

Status: Pending

Sex: Not specified

Target Recruitment: 42

Inclusion Criteria

Inclusion criteria for allergic asthma patients:
- Controlled, intermittant to mild persistant asthma patients (according to the updated (2007) GINA guidelines);
- FEV1 at baseline at least 80% of the predicted value;
- baseline bronchial hyperresponsiveness to histamine (PC20histamine) between 0.25 and 8 mg/ml;
- Skin-prick test positive to common allergens;
- Patients are treated with inhaled beta-2-agonists on demand only (twice a week or less);
- Age between 18 and 40 years;;Inclusion citeria for healthy subjects:
- FEV1 at baseline at least 80% of the predicted value and baseline;
- PC20histamine above 16 mg/ml;
- Skin-prick test negative to common allergens;
- Age between 18 and 40 years;

Exclusion Criteria

Exclusion criteria for allergic asthma patients:
- Moderate to severe asthma patients (according to the updated (2007) GINA guidelines);
- Allergic asthma patients with daily symptoms;
- Nocturnal symptoms more than once a week;
- Patients who have had an exacerbation during the past 6 months, as indicated by a course of systemic steroids or antibiotics;
- Patients that used (inhaled) steroids less than 6 weeks prior to the study;
- Smokers;
- Ex-smokers ( < 12 months or > 5 packyears);
- Circulating antibodies against rhinovirus type 16;
- Patients who are in close contact with young children (< 2 years), either professional or family related.;Exclusion criteria for healthy subjects:
- Healthy subjects with a history of pulmonary complaints;
- Smokers;
- Ex-smokers ( < 12 months or > 5 packyears);
- Circulating antibodies against rhinovirus type 16;
- Patients who are in close contact with young children (< 2 years), either professional or family related.

Study & Design

Study Type: Observational invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>With this project we will analyze the expression (mRNA and protein) and<br /><br>activity (tryptophan and kynurenine in serum and BALF) of indoleamine<br /><br>2,3-dioxygenase. In addition we will determine cell counts and phenotype of<br /><br>inflammatory cells in BALF, viral load and inflammatory mediator production in<br /><br>epithelial cells and BALF and apoptosis markers in BALF cells and airway<br /><br>epithelial cells. Endogenous standards will be used to compare between healthy<br /><br>indiviuals and allergic asthma patients and between the two different<br /><br>time-points (pre- and post-RV16 exposure). Regression analysis will be<br /><br>performed to link these parameters to clinical details (FEV1, PC20histamine,<br /><br>symptom scores for asthma and common colds).</p><br>

Secondary Outcome Measures