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.
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.
Study Type
OBSERVATIONAL
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.
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.
Goethe University
Frankfurt am Main, Germany
Change of severe bronchial hyperresponsiveness over time of five years.
Bronchial hyperresponsiveness will be defined by the provocation dose (PD) of methacholine causing a 20% drop of FEV1 (PD-20FEV1).
Time frame: five years
Bronchial responsiveness of parents
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).
Time frame: two years
Impact of atopy
Influence of atopy on the time course of bronchial hyperresponsiveness.
Time frame: five years
eNO
Influence of the level of exhaled NO on the time course of BHR.
Time frame: five years
Total-IgE
Influence of the level of total-IgE on the time course of BHR
Time frame: five years
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