Tuberc Respir Dis.  2006 May;60(5):497-509.

Diagnosis of Mycobacterium tuberculosis Infection using Ex-vivo interferon-gamma Assay

• Lee JY
• Shim TS

Abstract

Until recently, the tuberculin skin test (TST) has been the only tool available for diagnosing a latent TB infection. However, the development of new diagnostic tools, using the Mycobacterium tuberculosis (MTB)-specific early secreted antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10) antigens, should improve the control of tuberculosis (TB) by allowing a more accurate identification of a latent TB infection (LTBI). Antigen-specific interferon-gamma (IFN-gamma) assays have greater specificity in BCG-vaccinated individuals, and as less biased by nontuberculous mycobacterial infections. Many comparative studies have suggested that those assays have a higher specificity than the TST, and the sensitivity of these assays are expected to remarkably improved if more MTB-specific antigens can become available. Nevertheless, the major obstacle to the widespread use of these tests is the limited financial resources. Similar to other diagnostic tests, the predictive value of IFN-gamma assays depends on the prevalence of a MTB infection in the population being tested. Therefore, prospective studies will be meeded to establish the applicability of these new assays at multiple geographic locations among patients of different ethnicities, and to determine if the IFN-gamma responses can indicate those with a high risk of progressing to active TB.

Keyword

Interferon-gamma assay; Tuberculin test; Tuberculosis; Latent tuberculosis infection

MeSH Terms

Bias (Epidemiology)
Diagnosis*
Diagnostic Tests, Routine
Geographic Locations
Humans
Interferon-gamma*
Latent Tuberculosis
Mycobacterium tuberculosis*
Mycobacterium*
Prevalence
Skin Tests
Tuberculin
Tuberculin Test
Tuberculosis
Interferon-gamma
Tuberculin