[Specific interferon-gamma assays: a modern tool for tuberculosis diagnosis]

Compared with the tuberculin skin test, the antigen-specific interferon-gamma assays, using a combination of two antigens ESAT-6 and CFP-10, has higher specificity for the diagnosis of latent tuberculosis, better correlation with exposure to M. tuberculosis, no cross-reactivity due to BCG vaccination and less towards nontuberculous mycobacterial infection. Fewer false positive results in uninfected persons avoid the costs of unnecessary therapy and its possible side effects. In low endemic areas, interferon-y assays are useful in addition of diagnostic algorithm for individuals with suspected tuberculosis. Further studies are required to evaluate the utility of the interferon-gamma assays in specialised subgroups of patients (immunocompromised, young children, patients with extrapulmonary disease,...) and as a marker of disease activity.