Intrinsic Asthma, Allergic Asthma, Allergy, Bronchial Hyperresponsiveness
Conditions
Keywords
asthma, preschool child, bronchial hyperresponsiveness, methacholine challenge test, atopy
Brief summary
The aim of investigator´s clinical trial is to investigate 52 patients aged three to five years with viral-induced asthma and 52 patients aged three to five years with allergic asthma. Over a time-span of 5 years the investigators will explore lung function and bronchial responsiveness. The investigators plan to evaluate long-term clinical history of moderate to severe bronchial hyperresponsiveness in preschool children with asthma. Therefore factors like atopy in children, parental atopy and bronchial hyperresponsiveness will be explored.
Detailed description
A positive family history with prevalence of atopy, eczema, wheezing are well-known factors predicting asthma. Caudri et al. found more important predictors like perinatal transmission, parental use of inhalative medications and wheezing/dyspnea out of viral infections(5). Measurement of BHR in children was in most studies a second outcome parameter. Four visits will be performed, baseline and after 1, 3, and 5 years. At visit 1 the investigators will characterize all patients by a ISAAC survey. At each visit in children a methacholine challenge, a skin Prick test, eNO, RAST and total IgE will be performed. At visit 3 and 4 sputum will be induced. In parents only at the first visit a methacholine challenge will be performed. A genetic identification of ADAM33 gene from EDTA blood shall be provided. ADAMs are multidomain proteins with a metalloprotease domain, associated with airway remodelling. Visits should be kept in a time interval without asthma therapy and respiratory infection. To examine the feasibility of methacholine challenges in preschool children data measured in 2006 will be analysed.
Interventions
2 ml of liquid-dissolved methacholine in concentration of 16 mg/ml dosed in 5 steps of 0.01 mg, 0.1 mg, 0.4 mg, 0.8 mg, and 1.6 mg. 2 minutes after each step up an impulse oscillometry (IOS) and spirometry will be performed. the challenge will be stopped in case of a ≥ 20% decrease from baseline in FEV1 (PD20) and 0,2 mg Salbutamol will be given.
Sponsors
Johann Wolfgang Goethe University Hospital
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
3 Years to 5 Years
Healthy volunteers
No
Inclusion criteria
* informed consent * age 3 to 6 years * diagnosis asthma * pulmonary function: FEV1 (% pred.)≥ 70% * ability to carry out 2 reproducible flow volume loops * moderate to severe BHR (PD20 FEV1 ≤ 0,3 mg methacholine) * more than 4 weeks interval since last infection * 8 hours washout period of Short Acting Beta Agonist * 1 week washout period of Ipratropium Bromide * 1 week washout period of Long Acting Beta Agonist * 4 weeks washout period of Systemic Corticosteroids * 4 weeks washout period of Leukotriene Antagonists
Exclusion criteria
* Age \< 3 and \> 6 Years * Pulmonary function test: FEV1 (% pred.) \< 70% * Others chronic diseases or infections (e.g., HIV, tuberculosis, malignancy) * Incapability to perform spirometry * Current participation in another clinical trial
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change of severe bronchial hyperresponsiveness over time of five years. | five years | Bronchial hyperresponsiveness will be defined by the provocation dose (PD) of methacholine causing a 20% drop of FEV1 (PD-20FEV1). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Bronchial responsiveness of parents | two years | In parents at first visit bronchial hyperresponsiveness will be defined by the provocation dose (PD) of methacholine causing a 20% drop of FEV1 (PD-20FEV1). |
| Impact of atopy | five years | Influence of atopy on the time course of bronchial hyperresponsiveness. |
| eNO | five years | Influence of the level of exhaled NO on the time course of BHR. |
| Total-IgE | five years | Influence of the level of total-IgE on the time course of BHR |
Countries
Germany
Outcome results
None listed