Clinical Trial: Genetic Susceptibility TO Ozone-induced Airway Inflammation in Humans

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Interventional

Official Title: Genetic Susceptibility TO Ozone-induced Bronchial Airway Inflammatory Responses In Humans

Brief Summary: The principal purpose of this study is to identify hyper-responsive, responsive and non-responsive groups of healthy human subjects based on their airway neutrophilic response to ozone exposure, and to perform micro-array analyses on DNA collected from recovered airway cells to explore possible differences in gene expression profiles between the three groups

Detailed Summary:

Sputum assessment day: Subjects meeting the required health status following the medical screening will be provided with a verbal and written description of all experimental procedures and possible risks involved in their participation. All subjects will be required to provide written informed consent to participate in the study. The ability of subjects to produce adequate induced sputum samples will also be determined. Therefore the subjects will be asked to produce sputum following inhalation of hypertonic saline (3, 4 and 5%). Subjects should be able to produce at least 50 mg of sputum (selected plug) per sample. Each sputum sample must contain a total cell count of at least 100,000 cells, a differential cell count containing less than 40% squamous epithelial cells, and cell viability of at least 50%, thus minimizing variability in cell recovery and squamous cell contamination. Subjects who are effective sputum producers will then be scheduled for a training session. Subjects may still be excluded from the study if unable to perform adequate pulmonary function tests.

Training session: Training session will occur no less than 2 days prior to exposure

• Lung function tests, including spirometry and plethysmography (body box measurements).
• Introduction to the ozone exposure chamber.
• Instruction on how to use the treadmill, including a minute ventilation measurement to reach the level of exercise required for the study.
• Nitric oxide measurement - this measures the amount of nitric oxide (NO) present in expired air. An increased concentration of NO in exhaled air may be found in normal persons with acute inflammation during upper respiratory tract infections and in association with symptoms i
  Sponsor: University of North Carolina, Chapel Hill
  

  Current Primary Outcome: Airway neutrophilic response to ozone exposure [ Time Frame: 6-24 hours post challenge ]
  
  

  Original Primary Outcome: Same as current
  
  

  Current Secondary Outcome: expression of specific genes of interest in a subset of ozone-responsive and ozone-non-responsive subjects [ Time Frame: pre/ post exposure ]
  
  

  Original Secondary Outcome: Same as current
  
  Information By: University of North Carolina, Chapel Hill
  

  Dates:
  Date Received: February 6, 2009
  Date Started: February 2002
  Date Completion: September 2018
  Last Updated: September 8, 2016
  Last Verified: September 2016