- Requirements for Participation
- Types of Studies Performed
- General Information
- Consent Forms for Study Participation
Because TB is a lung disease and infection occurs by inhalation of the organism, we are also interested in the ability of lung cells to contain Mycobacterium tuberculosis (Mtb), the bacteria that causes tuberculosis (TB). These cells are obtained using the procedure of fiberoptic bronchoscopy, as described below. For many studies, we also obtain blood samples in order to compare the immune responses of lung and blood cells from the same individual.
We are seeking healthy non-smoking subjects to participate in our laboratory's studies of human immune responses to Mycobacterium tuberculosis (M. tuberculosis), the organism that causes tuberculosis (TB). We are specifically recruiting subjects who have a history of inactive (latent) M. tuberculosis infection (LTBI), as demonstrated by a positive TB skin test (also known as PPD or tuberculin test) or a positive blood test for TB (known as QuantiFERON testing). We are also recruiting volunteers who have received the TB vaccine BCG and do not have evidence of LTBI, as well as healthy-nonsmokers who have no history of LTBI.
Subjects aged 18-50 can participate. We cannot include individuals with asthma or other chronic lung diseases in our studies. Individuals with disorders of the immune system or who take medications that may interfere with normal immunity may be ineligible as well. If you have specific questions relating to your own medical history, please feel free to contact us.
1. Skin Testing and Blood Testing for Tuberculosis Infection
In interpreting our studies, it is important for us to know whether volunteer subjects have a history of exposure to Mtb. This is determined by performing PPD skin testing and, more recently, by QuantiFERON blood testing. Although many people have been tested previously, we usually request that new volunteers undergo testing for LTBI in our lab prior to participating in other parts of the study. The QuantiFERON blood test is more specific for Mtb infection than skin testing. As a result, this is the main test we current use in the lab to determine whether or not a volunteer been infected with M. tuberculosis.
For some studies, it is specifically required that subjects undergo PPD skin-testing, even if it has been done previously. For research purposes, we perform skin testing with the standard doses of PPD, as well as with a diluted dose of PPD and a dose of salt water alone. Subjects must return 48 hours later to have the skin-test sites examined.
2. Blood Drawing
In many of our studies, we look at the responses of subjects' blood cells to M. tuberculosis and M. tuberculosis proteins. Blood is obtained in sterile fashion from a vein in the arm. Generally we request donations of 60-150 mL (2 to 5 ounces) of blood, which is between 1/8th and 1/3rd of the amount of blood given in a standard Red Cross blood donation.
3. Research Bronchoscopy Procedures
Because TB is a lung disease and infection occurs by inhalation of the organism, we are also interested in the ability of lung cells to contain M. tuberculosis. To obtain these cells, we perform research bronchoscopy. The bronchoscope is a flexible tube that is similar in width to a pencil and is approximately 24 inches long. The procedures of bronchoscopy involves passing the bronchoscope through the nose or mouth into the breathing tubes. We then collect lung cells by putting salt water into a small area of the lung and then suctioning the salt water back out. The procedure is performed in a special floor of University Hospitals Cleveland Medical Center dedicated to research-related projects. Volunteers typically spend 90 minutes in the research facility, but most of this required time is spent in preparation for the procedure and observation afterwards. Subjects receive $150 for undergoing research bronchoscopy.
We also have an additional, and relatively new, project in which we are trying to assess how protective immune cells move into the lung in response to antigens of M. tuberculosis. This study involves 2 bronchoscopy procedures. In the first procedure, a small amount of the skin-test material PPD is placed into a localized area of one lung and salt water is placed into a similar area of the opposite lung. We then ask subjects to return for repeat bronchoscopy in which we wash out these same lung regions to see what cells have accumulated. Subjects receive $150 for each bronchoscopy procedure performed in this study.
We would like to emphasize that the actual Mtb bacteria will only be used in laboratory studies and that subjects will not be exposed to Mtb during their participation. Agreeing to participate in one part of our experiments does not imply that a volunteer has agreed to any additional parts of the study, and volunteers may choose to end their participation in at any time. We hope that this summary will be useful in explaining the goals of our studies and what is involved. If you are interested in participating or have further questions, please contact us for more information at firstname.lastname@example.org or by phone at (216) 368-0531.
To learn the more details about study procedures, you can review the consent forms used in this study at the links below:
- Skin testing and blood testing for latent tuberculosis infection (LTBI)
- Blood donations
- Research bronchoscopy with bronchoalveolar lavage (BAL)
- Clinical Evaluation
- Bronchoscopy with bronchoscopic challenge with PPD