Quantiferon TB Gold Plus/TB-IGRA (Qualitative)

Specimen Required

8cc-Lithium Heparin Vial (Two Vials)

Fasting Required

Purpose of the Test

The test is used to diagnose TB infection, especially in people who have been exposed to the TB bacteria but do not have symptoms of active TB. It is also used to screen people who are at high risk for TB infection, such as healthcare workers and people who have immigrated from countries with high rates of TB.

When this test is required

The test may be requested when a person has been exposed to the TB bacteria, has a weakened immune system, or has symptoms of TB, such as coughing, fever, and weight loss. It may also be used to monitor the response to treatment for TB infection.

What the Test Detects

The test measures the body’s immune response to the TB bacteria by detecting the release of interferon-gamma (IFN-gamma) from white blood cells that have been exposed to TB antigens. The presence of IFN-gamma in the blood indicates exposure to TB bacteria.

Preparation for the Test

No specific preparation is needed for the test.

Sample Requirements

A blood sample is required for the test.

Additional Notes

The test should be interpreted in conjunction with a person’s medical history, physical examination, and other laboratory tests. False-positive and false-negative results are possible, and the test may not be accurate in people with certain medical conditions, such as HIV infection. The test does not distinguish between latent TB infection and active TB disease, which requires additional testing.

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