View clinical trials related to Latent Tuberculosis.
Filter by:The aim of this study is to evaluate the safety of a new vaccine against Tuberculosis (RUTI) when administered to healthy adult volunteers, compared to placebo; and determine its safe dosage range. An initial evaluation of immune responses to the vaccine compared to placebo will also be undertaken. In the present Phase I clinical trial, four increasing doses of RUTI will be tested, the groups composed by 6 volunteers each. (Total of 24 volunteers). The escalation to a new dose to test will be done after the safety of the previous dose has been ensured. For each dose of FCMtb to test, each volunteer will be inoculated twice (at day 0 and day 28) with RUTI (4 volunteers) or placebo (2 volunteers) and will be followed-up up to 25 weeks from the first inoculation. The global length of the study will be approximately 15 months.
Background: The TB and HIV epidemics are closely linked in developing countries, where 450,000 children die from HIV annually. TB is a major cause of death in HIV-infected children and is reversing gains made in child survival. The traditional tuberculin skin test (TST) has limited diagnostic accuracy for detecting TB infection. Adult studies suggest that new blood-based diagnostic TB testing offers a quicker, more accurate way to diagnose TB infection. Such diagnostic testing may directly guide clinical management and preventive strategies in immune-suppressed HIV-infected children, who are at high risk of becoming TB diseased following infection. Data regarding the usefulness of these tests in children is currently limited. Objective(s) and Hypothesis(es): The investigators hypothesize that blood-based TB diagnostic testing can accurately identify children with TB infection. In a community with high rates of TB and HIV infection, the following specific aims will be investigated in HIV-infected and uninfected children: 1. assess the agreement between the TST and blood-based diagnostic testing, 2. compare the performance of the TST and blood-based diagnostic testing to a standardized history of TB exposure, 3. measure the impact of age, nutritional and immune status on children's response to blood-based testing, 4. describe factors that might modify children's response to testing over time, and 5) examine the effect of environmental exposures and previous vaccination on the TST, blood-based testing and other measures of immune responses to TB. Potential Impact: The benefits of an accurate, rapid diagnostic test of TB infection in children include 1) timely institution of treatment for TB infection to prevent severe disease and mortality, and 2) preclusion of over diagnosis and treatment. Treatment of childhood TB infection also prevents future contagious adult disease, thus decreasing community transmission. Blood-based diagnostic testing may also be able to identify children that are more likely to become ill following TB infection. Therefore, blood-based diagnostic testing has great potential to improve TB control and the health of HIV-infected and uninfected children, their households and communities.
Primary Objective: 1. To evaluate the performance of the new T-SPOT.TB test and the conventional TST for screening of Latent Tuberculosis infections in patients with cancer and those undergoing Hematopoietic Stem Cell Transplant. Secondary Objectives: 1. To examine the factors associated with positive response to T-SPOT.TB and the TST (tuberculin skin test) in patients with anergy. 2. To determine the impact of immunosuppressive and antineoplastic therapy on the screening performance of T-SPOT.TB and the TST in cancer patients.
The purpose of this study is to evaluate whether isoniazid can safely (and further) reduce the risk of tuberculosis in HIV infected people receiving HAART.
The purpose of this study is to study the effect that treatment of dormant tuberculosis infection has on the immunological system. We expect to observe an impact over the production of cytokines by peripheral white blood cells which may be useful to know if treatment has been effective.
This study will examine how the immune system responds to infection with Mycobacterium tuberculosis bacteria (bacteria that cause tuberculosis) in order to better understand how the germ produces infection and how the immune response might work to control the infection. Only about one in 10 people infected by M. tuberculosis become sick, sometimes years or even decades after exposure. It is not known why some people become sick and most do not, but the immune system of people who never develop disease may be better able to control the bacteria. This study will evaluate the latent form of M. tuberculosis infection to further the understanding of the immune mechanisms - particularly the role of certain white blood cells - involved in the disease process. Healthy volunteers 18 years of age and older may be eligible for this study. Candidates are screened with a medical history, family history of medical conditions, sexual history, history of drug use, physical examination and blood tests, including a test for HIV. People in Mali, West Africa, and in local health clinics in the United States may participate. At the start of the study, participants have blood tests and a tuberculin skin test (PPD test), which indicates whether a person has been exposed to tuberculosis bacteria. For the PPD, a tiny amount of liquid containing dead tuberculosis antigen is put under the skin of the forearm with a needle. The antigen cannot cause infection or disease. After 3 days, participants have another blood test and the site of the tuberculin test is examined for swelling that would indicate a positive result. Participants with a positive PPD have a chest x-ray to check for tuberculosis disease. Those whose x-ray is also positive are withdrawn from the study and referred to their doctor for evaluation and treatment. Those whose x-ray is negative return to the clinic within 3 weeks of the tuberculin test to give another blood sample. Participants whose PPD is negative have a second tuberculin test 10 to 21 days later and return 3 days after the test to determine if it is still negative or if it is positive. (Some people who are negative after the first test may test positive after the second procedure.) Those whose test is still negative end their participation in the study at that time. Participants whose second PPD is positive have a chest x-ray as described above, and those with a negative chest x-ray return in 3 weeks to donate one last blood sample. The purpose of the present study is to evaluate the latent form of this infection, the prevalence of which worldwide exceeds that of active disease. Our hypothesis is that in latent tuberculosis antigen specific effector memory CD4+ T cells are responsible for the generation of clinically measurable delayed type hypersensitivity and that central memory CD4+T cells are not directly involved in this process. We base this idea on the assumption that latent tuberculosis is a state of antigen persistence and that effector memory T cells should be maintained as long as antigen/infection is present. We propose to conduct this study in Mali, West Africa and local clinics in the U.S. Tuberculosis affects 593/100,000(2) individuals in Mali and most have been exposed to the disease. Additionally it would be important to evaluate the same parameters locally as latent infection is one of the major factors for reactivation tuberculosis in this country. Patients would be enrolled in 4 major groups: HIV-/TST- (Group A), HIV-/TST+ (Group B), HIV+/TST+(G roup C) and HIV+/TST- (Group D). To evaluate this hypothesis we plan to enroll between 100 - 300 patients over the course of 2 years from both countries. Blood samples before and at predetermined time points after the application of Purified Protein Derivative (PPD) will be obtained to determine the fraction of CD4+ T cells which produce interferon gamma in response to stimulation with PPD with a 16hr antigen stimulation assay. Appropriate staining will be done to ascertain the phenotype as well as cytokine production (Interferon gamma,( IFN gamma), Interleukin 2 (IL2) and Tumour Necrosis Factor ( TNF)). Additionally lymphocyte proliferation will be studied using 5-(and-6)-carboxyflouorescein diacetate succinimidyl ester (CFSE.) In conducting this study we hope to further the understanding of the immune mechanisms involved, particularly mechanisms of T cell memory, which would provide insights into TB and HIV pathogenesis. We also believe that understanding these mechanisms could lead towards establishment of surrogates for immunity in TB vaccine studies, which could enhance vaccine trial design. It might also help in understanding better the immunological dynamics of tuberculosis co-infection in individuals with HIV infection.
This study will determine the differential cumulative mean number of isoniazid (INH) pills completed over 9 to 12 months for adolescents assigned to one of the following two groups: 1) peer adherence coaching, parent training, and self-esteem/life skills counseling; or 2) self-esteem/life skills counseling alone. The study will also estimate the costs and cost effectiveness of peer adherence coaching versus control procedures; this will be done from a provider and societal perspective.
Tuberculosis (TB) is spread by airborne transmission from adults with active contiguous TB to children, especially those living in the same household. Once children are exposed and infected they are at very high risk to develop active TB - which can be lethal if not detected and treated promptly. This makes it very important to detect TB infection as soon as possible, and treat this while it is still latent or dormant. Current therapy for latent TB infection is 9 months of Isoniazid; this is very effective if taken properly but because treatment is so long many children do not finish this. Four months of Rifampin is a recommended alternative. In adults this has been shown to be safer with much higher completion rates. However the effectiveness of this treatment is unclear, and is being studied in an ongoing study. The investigators plan to compare the safety as well as the acceptability and effectiveness of 4 months Rifampin with 9 months Isoniazid (standard treatment) in children in several sites in Canada and other countries. It is hypothesized that among children at high risk for development of active TB, intolerance/adverse events will not be worse (non-inferiority), among those randomized to 4RIF compared to those randomized to 9INH. In addition completion of latent tuberculosis infection (LTBI) therapy will be significantly greater (superiority), and subsequent rates of active TB will not be significantly higher (non-inferiority) in children taking 4RIF.
The tuberculin skin test (TST) has been the gold standard for diagnosing latent tuberculosis for almost 100 years. While this test performs reasonably well in healthy, non-bacille Calmette-Guerin (BCG) vaccinated populations, it is believed to perform less well in patients who do not have intact cellular immune systems (immunocompromised). The investigators hypothesize that a new test, the T-SPOT TB ELISPOT test will provide a more accurate measurement of latent infection in immunocompromised people. This study will compare the TST to the T-SPOT TB ELISPOT test, and to the results of an expert physician diagnostic panel.
Open-label, multi-center, Phase III clinical trial to compare the effectiveness and tolerability of a three-month (12-dose) regimen of weekly rifapentine and isoniazid (3RPT/INH) to the effectiveness of a nine-month (270-dose)regimen of daily isoniazid (9INH) to prevent tuberculosis (TB) among high-risk tuberculin skin-test reactors, including children and HIV-infected persons, who require treatment of latent TB infection (LTBI).