Development of a Novel Non-invasive Inflammometry Following Allergen Challenge in Patients With Mild Allergic Asthma
The goal of this exploratory method-development study is to to establish and evaluate novel non-invasive methods to monitor airway inflammation induced by allergen challenge (both by instillation during bronchoscopy and by inhalation) in patients with mild allergic asthma. The investigator wants to further profile and develop the allergen challenge model by investigating the utility of various non-invasive monitoring methods. The hypothesis of the project is that local inflammatory changes in the lung induced by allergen can be captured by gas-enhanced magnetic resonance imaging (MRI) and analysis of exhaled breath. The validation of cellular outcome measures and non-invasive inflammometry can be used in future clinical trials for proof of concept of novel anti-inflammatory medications. Participants will undergo * methacholine challenge * 2 inhaled allergen challenges * 2 MRI with hyperpolarized xenon and gadolinium based contrast agent * 2 bronchoscopies with bronchoalveolar lavage (BAL) * segmental allergen challenge during the first bronchoscopy * spirometry * skin prick test and skin prick dilution tests * measurement of particles in exhaled air * nasal filter * nasal lavage * sputum induction * peak flow meter tests * exhaled NO (nictric oxide) * blood sampling (in total approx. 190 ml)
• Able and willing to give written informed consent.
• Male and female subjects aged 18-65 years. Women will be considered for inclusion if they are:
‣ Not pregnant, as confirmed by pregnancy test (see assessment schedule), and not nursing.
⁃ Of non-childbearing potential (i.e., physiologically incapable of becoming pregnant, including any female who is pre-menarcheal or post-menopausal, with documented proof of hysterectomy or tubal ligation, or meets clinical criteria for menopause and has been amenorrhoeic for more than 1 year prior to the Screening Visit).
⁃ Of childbearing potential and using a highly effective method of contraception during the entire study (vasectomised partner, sexual abstinence, implants, injectables, combined oral contraceptives, hormonal Intrauterine Devices (IUDs) or double-barrier methods, i.e. any double combination of IUD, condom with spermicidal gel, diaphragm, sponge, and cervical cap).
• History of mild asthma for at least 12 months prior to the Screening Visit that is well controlled with Short Acting Beta-Adrenergic Stimulator (SABA) only.
• Body mass index between 18 and 32 kg/m2
• Normal pulmonary function with forced Expiratory Volume in the first second (FEV1) ≥80% of predicted normal and FEV1/Forced Vital Capacity(FVC) ≥70% at Screening Visit. Calculations will be based on Global Lung Function Initiative (GLI) formula. If the participant fails to meet this criterion on the first measurement, spirometry may be repeated twice.
• Positive skin prick test (wheal diameter reaction ≥3 mm) for the respective challenge aeroallergen (i.e. tree, weed, grass or house dust mite) at or within 12 months prior to the Screening Visit (if performed and documented at Fraunhofer ITEM).
• Positive early and late asthmatic response upon incremental inhaled allergen challenge at or prior to the Screening Visit (if performed and documented at Fraunhofer ITEM).
• Production of adequate sputum with ≥1 x 106 total non-squamous cells at or within 12 month prior to the Screening Visit 1 (if not performed and documented at Fraunhofer ITEM).
• Nonsmokers with a history of less than 1 pack year having been nonsmokers for at least one year.