The first aim of the study is to determine the prevalence of latent infections by non invasive assessment of induced sputum, exhaled breath condensate and nasal/throat swabs in stable asthmatic patients and controls. The second aim is to value…
ID
Source
Brief title
Condition
- Respiratory tract infections
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The first aim of the study is to determine the prevalence of latent infections
by non invasive assessment of induced sputum, exhaled breath condensate and
nasal/throat swabs in stable asthmatic patients and controls.
Secondary outcome
The severity of airway inflammation based on sputum cell differentials
Background summary
Asthma is a disease characterized by variable airflow limitation and chronic
airway inflammation. There is overwhelming evidence that respiratory infections
are closely associated with exacerbations of pre-existing asthma and that
rhinovirus infection plays an important role. Furthermore, latent or persistent
infections may be responsible for the chronicity of airway inflammation.
We postulate that:
a. Patients with stable asthma have increased presence of viruses and bacteria
in the airways as compared to controls.
b. Severe asthmatic patients have a higher load of viruses and bacteria than
mild asthmatic patients.
c. Infections can be detected by non invasive sampling of the airways.
d. The presence of pathogens in the airways is reproducible with non invasive
techniques.
e. The persistent infections correlate with inflammatory markers measured in
the same samples.
Study objective
The first aim of the study is to determine the prevalence of latent infections
by non invasive assessment of induced sputum, exhaled breath condensate and
nasal/throat swabs in stable asthmatic patients and controls.
The second aim is to value whether the presence and types of bronchial
pathogens are associated with clinical severity of asthma.
The third aim is to determine whether the assessment of latent infections can
be reproduced after six weeks and twelve weeks from the first measurement.
The fourth aim is to investigate the associations between latent infections and
airways inflammation.
Study design
The study will have a cross-sectional design, including patients with asthma
and controls.
The study consists of three study phases:
1. Screening: a review of the medical history, physical examination, standard
spirometry, post-bronchodilator spirometry and methacholine challenge (in case
of uncertain diagnosis of asthma) will be performed.
2. Phase 1: nasal and throat swabs, breath condensate and induced sputum will
be collected.
3. Phase 2 and 3: the patients will repeat all the procedures included in phase
1 after six and twelve weeks, respectively.
Screening for viral and bacterial pathogens will be done with real-time
multiplex PCR on all the samples collected during the phase 1, phase 2 (after
six weeks) and phase 3 (after twelve weeks).
Study burden and risks
The current tests are purposely non-invasief. ( except the swabs) Sputum
induction will follow a safety protocol validated in severe asthma.
Meibergdreef 9
1105 AZ Amsterdam
Nederland
Meibergdreef 9
1105 AZ Amsterdam
Nederland
Listed location countries
Age
Inclusion criteria
- Men and/or women age between 18-65 years
- History of episodic chest tightness and wheezing (for the MILD and SEVERE astmatic patients)
- Prebronchodilator FEV 1 *80% predicted (for the MILD asthmatic patients)
- Reversibility in FEV1>12% predicted, or documented hyperesponsiveness (PC20 methacoline < 4mg/ml) during the past 12 months.
- Steroid-naïve (for the MILD asthmatic patients)
- Non smoking or ex-smokers (stopped more than 12 months ago and 5 pack year or less).
- Proven skin prick test. (for the MILD asthmatic patients)
- Use of high doses of inhaled corticosteroids (* 1000 µg/day beclomethasone or equivalent) and long acting bronchodilators for more than 12 months. (for the SEVERE athmatic patients)
- One severe asthma exacerbation requiring oral steroid therapy during the past 12 months. (for the SEVERE athmatic patients)
- Baseline FEV1*75% of predicted or negative documented airway hyperresponsiveness (PC20 methacoline>8mg/ml) (for the HEALTHY subjects)
- Negative history of pulmonary and any other relevant diseases. (for the HEALTHY subjects)
Exclusion criteria
- History of current alcohol or drug abuse, as judged by the investigator.
- Subjects who have had an exacerbation or a chest infection within the last 4 weeks prior to the study.
- Uncontrolled hypertension-systolic blood pressure(BP)>200 mmHg and/or diastolic BP>100 mmHg.
- Concomitant disease or condition which could interfere with the conduct of the study or which would, in the opinion of the investigator, pose an unacceptable risk to the patient in this study
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| Other | Is in aanvraag |
| CCMO | NL20639.018.08 |