Immunological phenotype of asthma severity (iPhase)

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 100

Inclusion Criteria

In order to be eligible to participate in this study, a subject must meet one of the following criteria:
- Diagnosis of asthma confirmed by at least one of the following as assessed at least once during the 5 past years before the study:
- 1. Reversibility to β2-agonists as shown by an increase from baseline in FEV1>= 12% predicted and >= 200 ml after 400 µg inhaled salbutamol or equivalent;
- 2. Bronchial hyper-responsiveness (BHR) to metacholine (PD < 1.76) or histamine (PD < 2.59) as measured by standardized methods.
- 3. Peak-flow variability of >20% ((PEFmax - PEFmin)/PEFmax) over a period of 14 days.
- 4. Fall in FEV1>12% and >200ml when tapering of treatment (ICS, oral steroid, LABA and/or LTRA). ;We will include patients diagnosed with asthma and a recent (< 12 monts) metacholine provocation test, or histamine provocation test (PD20 < 1.76 mg). These test are performed in a standardized manner in both centers.
o In this study we will compare three different asthmatic phenotypes. These phenotypes will be determined based on clinical features and inflammatory sputum profile;
- Use inhaled corticosteroids daily and β2-agonists as required;
- Given written informed consent;
- Age: 18 - 50.

Exclusion Criteria

A potential subject who meets any of the following criteria will be excluded from participation in this study:;- received systemic corticosteroid therapy (>= 7.5 mg/kg) within three months prior to inclusion;
- no use of inhaled corticosteroids and β2-agonists
- BMI > 35;
- Smoking > 10 pack years;
- Other diseases which could influence pulmonary function and/or the immune system such as:
o A possible infection of the upper- or lower respiratory tract 4 weeks prior to the collection of materials;
o Chronic obstructive pulmonary disorder (COPD) in the medical history;
o Auto-immune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), myasthenia gravis or Goodpasture*s syndrome;
o Malignancies;
o Human immunodeficiency virus (HIV);
o Pregnancy;
o Other allergies except for allergic rhinitis.

Study & Design

Study Type: Observational invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Cell numbers and activation of Th subsets, DCs, ILC2s and granulocytes will be<br /><br>determined in peripheral blood and induced sputum of controlled, partly<br /><br>controlled and uncontrolled asthma patients and healthy controls.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>- To compare the differences in activation status in DCs, and to identify<br /><br>correlations with immunological and clinical disease phenotype<br /><br>- To compare the differences in activation status in T cell subsets, and to<br /><br>identify correlations with immunological and clinical disease phenotype<br /><br>- To establish whether T helper cell polarization by DCs is altered in asthma<br /><br>patients<br /><br>- To find correlations between ILC2 numbers and characteristics and<br /><br>immunological and clinical disease phenotype</p><br>