Towards Targeting the ORigin of the Inflammatory Cascade in Allergic Asthma

Inclusion Criteria: Inclusion criteria for all subjects: * Age between 18 and 45 years old. * Smoking history ≤2 packyears. Specific inclusion criteria for the two groups: * Group 1. Patients with ongoing asthma * Age of onset of asthmatic symptoms: 0 - 18 years. * Documented history of asthma diagnosed according to latest GINA guidelines, i.e. respiratory symptoms and either bronchodilator reversibility (improvement in FEV1 of more than 12% of baseline (and at least 200 mL) after inhalation of 800 µg salbutamol). * Use of inhaled corticosteroids or either persistent symptoms of wheeze, cough, or dyspnea or regular use of β2 agonists at least once a week during the last 2 months. * PC20 methacholine \< 8 mg/ml. * Group 2. Non-asthmatic controls * No history of asthma. * No use of inhaled corticosteroids or β2-agonists for a period longer than 1 month. * No symptoms of wheeze, nocturnal dyspnea, or bronchial hyperresponsiveness. * PC20 methacholine \> 8 mg/ml, FEV1/FVC \> 70% and FEV1 \> 80% predicted. Exclusion Criteria: * FEV1 \<1.2 L, * Subjects must be able to adhere to the study visit schedule and other protocol requirements. * A subject is not eligible to enter and participate if he has not signed and dated a written informed consent form prior to participation in the study. * A subjects is not eligible to enter and participate if he does not agree that we inform his general practitioner. * Upper respiratory tract infection (e.g. colds), within 6 weeks. * Serious acute infections (such as hepatitis, pneumonia or pyelonephritis) in the previous 3 months. * Signs or symptoms of severe, progressive or uncontrolled renal, hepatic, hematologic, endocrine, pulmonary, cardiac, neurologic or cerebral disease. * Malignancy within the past 5 years (except for squamous or basal cell carcinoma of the skin that has been treated with no evidence of recurrence). * Known recent substance abuse (drug or alcohol). * Females of childbearing potential without an efficient contraception unless they meet the following definition of post-menopausal: 12 months of natural (spontaneous) amenorrhea or 6 months of spontaneous amenorrhea with serum FSH \>40 mIU/mL or the use of one or more of the following acceptable methods of contraception: 1. Surgical sterilization (e.g. bilateral tubal ligation, hysterectomy). 2. Hormonal contraception (implantable, patch, oral, injectable). 3. Barrier methods of contraception: condom or occlusive cap (diaphragm or cervical/vault caps) with spermicidal foam/gel/cream/suppository. 4. Continuous abstinence.