A Phase 1 interventional study of Endotoxin - lipopolysaccharide (LPS) in Atopic Asthma and Healthy, sponsored by John Sundy. Terminated at 1 site in United States. Open to participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2013-07-16.
Sponsored by John Sundy · Phase 1, Interventional, and Basic science
The purpose of this study is to identify the mediators and genes in airway epithelial and BAL cells that are differentially regulated following inhalation of endotoxin lipopolysaccharide (LPS) among study participants with allergic asthma and normal phenotypes. This approach is designed to identify novel genes associated with both asthma pathogenesis and asthma susceptibility. LPS, or endotoxin, a cell wall component of gram-negative bacteria, is ubiquitous in the environment, and is thought to influence both susceptibility and severity of asthma.
240 subjects (healthy adult men and women (age >18-40) with and without atopy and asthma) will complete the screening evaluations in order to establish 3 study groups of 60 subjects each. Each qualified subject will undergo an inhaled LPS endotoxin challenge followed by bronchoscopy after 24 hours, which will consist of a bronchoalveolar lavage (BAL) and endobronchial brush biopsies. BAL involves squirting a small amount of sterile salt water into one of the airways then gently taking it back out through the bronchoscope. The brush sample involves gently moving a small brush back and forth in an airway to collect cell samples. Samples of whole blood will also be obtained at various time points. RNA will be isolated from these cell populations in order to assess differential gene expression expression using microarrays.
Background:
Endotoxin or lipopolysaccharide (LPS), a cell wall component of gram-negative bacteria, is ubiquitous in the environment, and is often present in high concentrations in organic dusts, as well as in air pollution, and household dusts. There is convincing evidence that endotoxin exacerbates airflow obstruction and airway inflammation in allergic asthmatics. Additional findings indicate that allergic airways can enhance the response to inhaled endotoxin, and that endotoxin can enhance the airway response to allergens. However, when considering the interaction between endotoxin and allergens, the timing of the exposure appears to be critical. Emerging evidence suggests that early exposure to endotoxin, a potent inducer of Th1 type cytokines (IFN-g and IL-12), may minimize the risk of allergen sensitization which could has profound effects on reducing the risk of developing asthma in children. Independent of its effect in allergic asthma, several studies demonstrate that inhalation of air contaminated with endotoxin is associated with the classical features of asthma (reversible airflow obstruction and airway inflammation, and persistent airway hyperreactivity and airway remodeling). Epidemiological studies have shown that the concentration of inhaled endotoxin in the bioaerosol is strongly and consistently associated with reversible airflow obstruction among cotton workers, agricultural workers, and fiberglass workers. Importantly, the concentration of endotoxin in the bioaerosol is the most important occupational exposure associated with the development and progression of airway disease in agricultural workers. Experimentally, inhalation of endotoxin can cause reversible airflow obstruction and airway inflammation in previously unexposed healthy study subjects. The ability of the host to respond to endotoxin is highly variable, and is influenced in part by genetic factors.:
The rationale for this investigation is based on the following points:
3,921 studies on the registry are indexed under Asthma; 507 are open to participants now.
This study's enrollment of 17 is below the median of 83 across 2,752 interventional studies indexed under Asthma.
Browse Asthma studies →John Sundy is the lead sponsor of 6 studies on the registry; none are open to participants now.
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Exclusion Criteria:
Participants receive inhalation of LPS endotoxin, followed by bronchoscopy in this study.
Biological: Endotoxin - lipopolysaccharide (LPS)
Nebulized 5000EU, 10,000EU, 20,000EU endotoxin doses delivered to completion. Nebulized dose inhaled 30 minutes apart if no adverse events occur after the previous dose. Fiberoptic Bronchoscopy with Bronchoalveolar Lavage (BAL) and brush samples performed 24 hours after LPS nebulization.
Also known as: Lipopolysaccharide (LPS), NIH Clinical Center Reference Endotoxin
Identify Genes in airway epithelial and Bronchoalveolar Lavage (BAL)that are differentially regulated following inhalation of LPS endotoxin.
Time frame: bronchoscopy performed 24 hours after inhalation of endotoxin
Identify mediators in airway epithelial and BAL cells that are differentially regulated following LPS inhalation.
Time frame: Bronchoscopy performed 24 hours post inhalation of endotoxin
This study is terminated, as verified in Jul 2013. You cannot join it, but the record below documents what was studied.
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