Quick Facts
- Sample: Blood
- Fasting: No fasting required
- Turnaround: 2-5 days (may take longer based on weather, holiday, or lab delays)
What This Test Measures
The QuantiFERON TB Gold Plus Blood Test is an Interferon-gamma Release Assay (IGRA) that looks for signs of an immune reaction to Mycobacterium tuberculosis. Using a blood sample, this test evaluates how your immune system responds to TB-specific antigens, helping identify evidence of TB infection.
This test reports results based on your immune system's reaction rather than directly visualizing the bacteria itself. It does not distinguish between latent TB infection and active TB disease. The test has specificity as high as 99% in TB disease detection.
Benefits
- Simple blood draw instead of a skin test visit
- FDA-approved method to screen for TB infection
- High specificity in TB disease detection
- Convenient alternative to traditional TB skin testing
- No fasting required before your blood draw
Who Is This Test For?
- People experiencing symptoms associated with TB, such as persistent cough
- Individuals working or living in settings where TB is more common
- People who work in healthcare, shelters, or correctional facilities
- Those with health conditions that affect the immune system's ability to fight TB
- People previously infected with TB within the last two years
- Individuals who were not appropriately treated for TB in the past
How It Works
- Order Your Test Online
- Visit a Local Lab
- Get Results Online
FAQ
1. What is the purpose of this test?
This test helps screen for TB infection by measuring your immune system's reaction to Mycobacterium tuberculosis antigens using a blood sample. It may help a healthcare provider evaluate whether you have signs of an immune response consistent with TB exposure. This test does not independently diagnose TB disease or determine whether an infection is latent or active.
2. Who would benefit from this test?
This test may be appropriate for individuals who work or live in settings where TB is more common, such as healthcare facilities, shelters, or jails. It may also be considered by people with health conditions that make it harder to fight TB bacteria, or those previously infected with TB within the last two years. People not appropriately treated for TB in the past may also consider this test.
3. When should I order this test?
You may consider ordering this test if you have experienced symptoms associated with TB disease, such as a persistent cough lasting more than three weeks, night sweats, unexplained weight loss, or chest discomfort. It may also be considered by individuals with known exposure risk factors described in the source material. This test does not replace a full medical evaluation.
4. What does this test measure?
This test measures your immune system's response to Mycobacterium tuberculosis antigens using a blood sample, reported through the QuantiFERON-TB Gold Plus assay. Reported values include measures such as the Mitogen-Nil, Nil, TB1 Ag, and TB2 Ag values, along with the QuantiFERON criteria used to interpret the reaction pattern. This is a blood-based test and does not use other specimen types.
5. Do I need to fast before this test?
No fasting is required for this test. This test does require a special collection kit that may not be available at all LabCorp locations, so contact your local LabCorp draw site to confirm kit availability before your visit.
6. How quickly will I get results?
Results are typically available in 2-5 days. Results may take longer based on weather, holiday, or lab delays.
7. How do I interpret the results?
The meaning of your result depends on your immune response pattern, medical history, symptoms, and other clinical factors. Your healthcare provider will consider your individual circumstances, including exposure history and any related test results, when reviewing your report. A reactive or non-reactive result should be interpreted in context, not on its own.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
8. What should I do if my results are abnormal?
If your results fall outside expected ranges, review them with a qualified healthcare provider. They can help interpret your result in the context of your health history and determine whether additional evaluation may be appropriate. This test result alone does not provide a complete clinical conclusion.
9. How often should I get tested?
There is no set testing schedule for this test. How often you may need testing should be determined by your healthcare provider based on your individual circumstances and ongoing risk of TB exposure.
Pre test preparation
No fasting is required.
