Get Quantiferon-tb

The QuantiFERON(R) TB Gold (in Tube) assay is intended for use as an aid in diagnosis of TB infection. Negative results suggest that there is not TB infection. In patients with high suspicion of exposure, a negative test should be repeated. A positive test indicates infection with Mycobacterium tuberculosis.

You have a positive Tuberculin Skin Test (TST) or QuantiFERON blood test: what does this mean? If your TST (Mantoux) or Quantiferon blood test was found to be positive, this means you have a latent TB infection, but usually not the active disease.

Quantiferon-TB Gold Plus (QFT-Plus) is an gamma release assay used to diagnose latent tuberculosis (LTB). A borderline range (0.20 to 0.99 IU/ml) around the cutoff (0.35 IU/ml) has been suggested for the earlier QFT version.

QuantiFERON-TB Gold (QFT) is a simple blood test that aids in the detection of Mycobacterium tuberculosis, the bacteria which causes tuberculosis (TB). QFT is an -gamma (IFN-γ) release assay, commonly known as an IGRA, and is a modern alternative to the tuberculin skin test (TST, PPD or Mantoux).

A “positive” TB blood test result means you probably have TB germs in your body. Most people with a positive TB blood test have latent TB infection. To be sure, your doctor will examine you and do a chest x-ray. You may need other tests to see if you have latent TB infection or active TB disease.

A positive test result suggests that M. tuberculosis infection is likely; a negative result suggests that infection is unlikely. An indeterminate result indicates an uncertain likelihood of M. tuberculosis infection.

TB test detects individual memory T cells that produce IFN-γ in response to M. tuberculosis antigens, using the enzyme-linked immunospot technique. The QuantiFERON-TB Gold test measures IFN-γ in the supernatant of antigen-stimulated cells by enzyme-linked immunoassay.