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Case Western Reserve University Tuberculosis Research Unit
  Integrating research to combat the global TB epidemic
 
 

Phase I Study of Whether Preclearance of Latent M. tuberculosis (MTB) Infection with Isoniazid (INH) Enhances Specific Immune Response to MTB Following Subsequent BCG Revaccination in Healthy, HIV-uninfected, Tuberculin Skin Test Positive Adults

(DMID Protocol Number: 07-0083)

Type of Study

Phase 1 Clinical Trial

Design

Randomized, Parallel Arm, Open-Label Phase 1 Clinical Trial

Project Site

South African Tuberculosis Vaccine Initiative (SATVI), Worcester, South Africa

Sample Size

82 subjects

Population

Healthy, HIV-uninfected, TST+ adults 18-40 years old with prior BCG vaccination in infancy

Study Period

2009-Present

Goal of Study:

Current TB vaccination strategies have little protective efficacy against the development of pulmonary TB in adults - the main source of TB transmission in the community. Earlier studies also have shown little benefit from revaccination with current BCG vaccines. TST positive adults with latent TB infection represent the largest group (an estimated one-third of the world’s population or 2 billion persons) at risk for TB. Recent data suggest that preclearance (treatment of LTBI) with isoniazid (INH), which decreases or eliminates latent tubercle bacilli, may result in enhanced MTB specific immune responses. This trial will test the hypothesis that the effect of preclearance of latent MTB infection with INH treatment will enhance immune responses to BCG revaccination.

Objectives of Study:

Primary Objectives:

  1. Determine the effect of INH preclearance on the kinetics and characteristics of the specific immune response following BCG revaccination in adults with latent M. tuberculosis (MTB) infection (TST positive).
  2. Determine the safety and reactogenicity of BCG revaccination in TST+ adults.

Secondary Objectives:

  1. Determine the effect of INH preclearance and BCG revaccination on MTB-specific Th1 effector and central memory cell function.
  2. Determine the effect of INH preclearance and BCG revaccination on MTB-specific Treg cell function.
  3. Determine the effect of INH preclearance and BCG revaccination on innate immune responses as measured by T cell mediated inhibition of intracellular mycobacterial growth and inflammatory cytokine production.
  4. Determine weather a host gene expresion signature can predict immunological outcome of BCG vaccination.
Research Activities: