A Trial of Isoniazid for the Reversion of Interferon Gamma ELISPOT in Tuberculosis (TB) Case Contacts (IRS)
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|ClinicalTrials.gov Identifier: NCT00130325|
Recruitment Status : Completed
First Posted : August 15, 2005
Last Update Posted : January 13, 2010
There are new TB vaccines already developed that need to be tried in humans to assess their efficacy.
The researchers had previously shown that production of interferon gamma by T cells in response to TB antigens is a more specific marker of TB infection.
The researchers hypothesize that this can be used as a reliable early marker of TB vaccine efficacy. The researchers expect to show a significantly increased reversion of this test in household contacts of TB patients given Isoniazid prophylaxis treatment for 6 months.
|Condition or disease||Intervention/treatment||Phase|
|Tuberculosis||Drug: Isoniazid Drug: Placebo of Isoniazid tablets 300mg||Not Applicable|
Current efforts to control the spread of tuberculosis are failing. An increasingly large number of new generation vaccines are being produced and a plan for assessing their ability to prevent disease and treat infection needs to be developed.
The MRC Labs in The Gambia is well positioned to conduct safety and immunogenicity studies and also to conduct trials of the therapeutic effect of these vaccines in preventing disease in case contacts who are infected.
This study is part one of a three-step plan to develop a reliable early surrogate marker of the therapeutic efficacy of new TB vaccines.
The three-step plan is as follows:
- Evaluate the ability of isoniazid, known to be effective in the treatment of MTB infection, to revert the antigen-specific IFNg-ELISPOT in ESAT-6 and/or CFP-10 positive contacts of TB patients.
- Compare the ability of different combinations of a TB vaccine and isoniazid to revert the ELISPOT in a 4-arm randomised trial using:1) isoniazid alone, 2) a TB vaccine alone, 3) a combination of isoniazid and TB vaccine, and 4) placebo
- Compare, in a randomized trial, the ability of TB vaccine or vaccine plus isoniazid versus isoniazid alone to prevent the development of secondary disease.
For this first step the researchers will test the following hypothesis:
- Those receiving isoniazid have a significantly higher reversion rate of MTB-specific responses as measured with IFNg-ELISPOT assays compared to those who receive a placebo.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||214 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||Triple (Participant, Investigator, Outcomes Assessor)|
|Official Title:||A Double Blind Placebo-controlled Randomized Trial of Isoniazid for the Reversion of a Positive IFNg ELISPOT in TB Case Contacts|
|Study Start Date :||October 2004|
|Actual Primary Completion Date :||October 2008|
|Actual Study Completion Date :||June 2009|
Active Comparator: A
Isoniazid 900mg, tablets, twice a week for 6 months
INH 900mg twice weekly for 6 months
Placebo Comparator: B
Placebo of Isoniazid tablet 300mg
Drug: Placebo of Isoniazid tablets 300mg
Isoniazid BP 0mg twice weekly for 6 months
- Qualitative IFN-g ELISPOT reversion [ Time Frame: 12 months ]
- Quantitative IFN-g ELISPOT reversion [ Time Frame: 12 months ]
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00130325
|Banjul, Ksmd, Gambia, Po Box 273 Banjul|
|Principal Investigator:||Philip C Hill, MPH FRACP||MRC Laboratories, Gambia|
|Principal Investigator:||Roger H Brookes, PhD||MRC laboratories, Gambia|
|Study Chair:||Richard A Adegbola, PhD FRCPath||MRC laboratories, Gambia|