Allergic Asthma
Conditions
Keywords
asthma, allergy, bronchial hyperresponsiveness, provocation
Brief summary
The purpose of this study is to establish the methodology of bronchial provocation tests with house dust mites in China, and to evaluate its safety and effects on upper and lower airways inflammation.
Detailed description
After screening,each participant undergo baseline lung function test,airway inflammation evaluation (blood and sputum eosinophils count,interleukin-13 (IL-13),FeNO)and airway responsiveness tests(methacholine bronchial provocation,nasal histamine provocation). On the second day,the participant undergo bronchial house dust mites challenge tests. On the third day,the participant undergo the lung function test,airway inflammation evaluation (blood and sputum eosinophils count,IL-13,FeNO)and airway responsiveness tests(methacholine bronchial provocation,nasal histamine provocation).
Interventions
OTHERhouse dust mites
house dust mites(two-fold increasing concentration of house dust mite (HDM) extract, dilutions prepared starting from 1:8, 1:16, 1:32, 1:64, 1:128, 1: 256, 1:512, 1:1024,……)
Sponsors
Firestone Institute for Respiratory Health
Guangzhou Institute of Respiratory Disease
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Clinical diagnosis of asthma; * Sensitive to house dust mite; * Stable for more than 4 weeks with FEV1≥70%pred
Exclusion criteria
* exacerbation within 3 months; * upper airway infections within 6 weeks; * concomitant of hypertension or heart diseases; * pregnancy
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| percentages of the participants that tested positive to house dust mites bronchial provocation | 30 minutes after house dust mites bronchial provocation |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Changes of the percentages of eosinophils in sputum, nasal lavage and fractional exhaled nitric oxide (FeNO) from baseline | 30mins, 7 and 24 hours after bronchial challenge | — |
| Changes of provocative concentration induced a 20% decrease in forced expiratory volume at one second (FEV1) to methacholine before and after house dust mites bronchial provocation | 24 hours after house dust mites bronchial challenge | — |
| percentages of the participants that tested positive to house dust mites bronchial provocation measured by impulse oscillometry | 10 minutes after house dust mites bronchial provocation | — |
| Changes of provocative concentration induced a 60% increase in nasal airway resistance to histamine before and after house dust mites bronchial provocation | 24 hours after house dust mites bronchial challenge | By Comparison with methacholine provocation test |
Other
| Measure | Time frame | Description |
|---|---|---|
| correlate of IL-4,IL-13,periostin with provocative concentration induced a 20% decrease in FEV1 to house dust mite in asthmatic | 30 mins and 24 hours after house dust mites bronchial challenge | By Comparison with methacholine provocation test |
| Incidence and Severity of Adverse Events During The House Dust Mite Bronchial Provocation Test | 30 minutes, 7 hours and 24 hours after house dust mites bronchial provocation | By Comparison with methacholine provocation test at 30 min and 24 hours after challenge test. |
Countries
China
Outcome results
None listed