T-SPOT.TB

T-SPOT.TB is a type of ELISPOT assay used for tuberculosis diagnosis in Europe. It counts the number of effector T cells, white blood cells that produce gamma interferon, in a sample of blood. This gives an overall measurement of the antigen load on the immune system, which can reveal the presence of subclinical disease. Because this does not rely on production of a reliable antibody response or recoverable pathogen, the technique can be used to detect conditions such as latent tuberculosis.