T-cell assays for the diagnosis of latent tuberculosis infection: moving the research agenda forward.
For nearly a century, the tuberculin skin test was the only tool available for the detection of latent tuberculosis infection. A recent breakthrough has been the development of T-cell-based interferon-gamma release assays. Current evidence suggests interferon-gamma release assays have higher specificity than the tuberculin skin test, better correlation with surrogate markers of exposure to Mycobacterium tuberculosis in low-incidence settings, and less cross-reactivity as a result of BCG vaccination compared with the tuberculin skin test. The body of literature supporting the use of interferon-gamma release assays has rapidly expanded. However, several unresolved and unexplained issues remain. To address these issues, a group of experts met in Geneva, Switzerland, in March, 2006, to discuss the research evidence on T-cell-based assays, their clinical usefulness, limitations, and directions for future research, with a specific focus on resource-limited and high HIV prevalence settings. On the basis of 2 days of discussions, a comprehensive research agenda was generated, which will propel the field forward by stimulating focused high-impact research and encourage the investment of resources needed to tackle priority research questions, especially in resource-limited settings. Ultimately, if adequately financed, the research findings will inform appropriate use of novel latent tuberculosis infection diagnostics in global tuberculosis control.
Pai
Madhukar
M
McGill University, Department of Epidemiology, Biostatistics and Occupational Health, Montreal, Quebec, Canada.
Dheda
Keertan
K
Cunningham
Jane
J
Scano
Fabio
F
O'Brien
Richard
R
D003955:Diagnostic Tests, Routine / Q000379:methods* / Q000592:standards; D006801:Humans; D007111:Immunity, Cellular; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013557:Switzerland; D013601:T-Lymphocytes / Q000276:immunology*; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis* / Q000276:immunology*