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A Trial of Isoniazid for the Reversion of Interferon Gamma ELISPOT in Tuberculosis (TB) Case Contacts (IRS)

This study has been completed.
Information provided by:
Medical Research Council Unit, The Gambia Identifier:
First received: August 11, 2005
Last updated: January 12, 2010
Last verified: January 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 Intervention
Drug: Isoniazid
Drug: Placebo of Isoniazid tablets 300mg

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Double Blind Placebo-controlled Randomized Trial of Isoniazid for the Reversion of a Positive IFNg ELISPOT in TB Case Contacts

Resource links provided by NLM:

Further study details as provided by Medical Research Council Unit, The Gambia:

Primary Outcome Measures:
  • Qualitative IFN-g ELISPOT reversion [ Time Frame: 12 months ]
  • Quantitative IFN-g ELISPOT reversion [ Time Frame: 12 months ]

Enrollment: 214
Study Start Date: October 2004
Study Completion Date: June 2009
Primary Completion Date: October 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: A
Isoniazid arm
Drug: Isoniazid
Isoniazid 900mg, tablets, twice a week for 6 months
Drug: Isoniazid
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

Detailed Description:

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.

Ages Eligible for Study:   15 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Healthy person aged 15 years and above
  • Normal medical history and physical examination
  • Normal biochemistry and haematological indices
  • Mantoux ≥ 10mm
  • Negative HIV antibody test
  • No serological evidence of hepatitis B virus (HBV) infection
  • Normal Chest X-ray
  • ESAT6 and/or CFP-10 peptides and ESAT6/CFP-10 protein positive (≥10 SFC for ESAT 6 or CFP-10 and ESAT6/CFP-10 protein).
  • Index case is sputum smear positive
  • Index case has chest X ray (CXR) characteristics of TB

Exclusion Criteria:

  • Pregnant female
  • Haemoglobin <8 g/dl
  • Previous history of tuberculosis
  • Clinical case of tuberculosis
  • Current participation in another clinical trial, or within 12 weeks of this study.
  • Any other factor that might increase the risk of an adverse outcome from participation in the trial
  • Significant history or evidence of skin disorder, allergy, immunodeficiency, organ specific disorders causing significant immunodeficiency.
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Please refer to this study by its identifier: NCT00130325

MRC Laboratories
Banjul, Ksmd, Gambia, Po Box 273 Banjul
Sponsors and Collaborators
Medical Research Council Unit, The Gambia
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
  More Information

Additional Information:
Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Prof. Tumani Corrah, Unit Director, MRC (UK) Laboratories, The Gambia Identifier: NCT00130325     History of Changes
Other Study ID Numbers: IRS SCC965
Study First Received: August 11, 2005
Last Updated: January 12, 2010

Keywords provided by Medical Research Council Unit, The Gambia:
Mycobacterium tuberculosis
Clinical trial

Additional relevant MeSH terms:
Mycobacterium Infections
Actinomycetales Infections
Gram-Positive Bacterial Infections
Bacterial Infections
Antitubercular Agents
Anti-Bacterial Agents
Anti-Infective Agents
Fatty Acid Synthesis Inhibitors
Hypolipidemic Agents
Molecular Mechanisms of Pharmacological Action
Lipid Regulating Agents processed this record on April 26, 2017