interferon gamma assay for tuberculosis


interferon gamma assay for tuberculosis

Any test for latent tuberculosis that relies on the amount of interferon gamma (IFNγ) released by T cells that have been previously exposed to mycobacterial antigens. One such test, the whole blood assay, is performed by withdrawing about 1 ml of whole blood from the vein of a patient. This blood is heparinized, to prevent clotting, and then mixed with specific mycobacterial antigens and control substances. After overnight incubation, samples of plasma from the blood are tested for INFγ levels. The test is considered positive if INFγ in a sample exposed to mycobacterial antigens is > 0.35 IU/ml. See also: assay