[Specific immune-based diagnosis of tuberculosis infection].
Two blood tests have been developed that detect tuberculosis (TB) infection by measuring in vitro T-cell interferon (IFN) -gamma release in response to unique antigens that are highly specific to Mycobacterium tuberculosis. One assay, the enzyme-linked immunospot (ELISpot) [T-SPOT, TB; Oxford Immunotec; Oxford, UK], enumerates IFN-gamma-secreting T cells, while the other measures IFN-gamma concentration in the supernatant by enzyme-linked immunosorbent assay (ELISA) [QuantiFERON-TB Gold; Cellesist, Carnegie, Australia]. Clinical evidence indicates that both tests are more specific than the century-old tuberculin skin test (TST) because they are not influenced by prior Bacille Calmette-Guerin vaccination. Meta-analysis shows that pooled specificity was 97.7% and 92.5% for QFT and Elispot, respectively, and the sensitivity of these tests was suboptimal when newly diagnosed active tuberculosis was used as a surrogate for latent TB infection. These tests are considered to be superior to TST and will replace it for detecting TB infection.
Yotsumoto
Hideki
H
National Hospital Organization, Tokyo National Hospital, Kiyose, Tokyo 204-8585, Japan. yotumoto@tokyo.hosp.go.jp
D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D007371:Interferon-gamma / Q000378:metabolism; D009169:Mycobacterium tuberculosis / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis*
D007371:Interferon-gamma