What Is Tested
This QuantiFERON-TB Gold Plus Test is a blood test designed specifically to detect the presence of M. tuberculosis bacteria (MTB). Unlike tests that detect antibodies, it focuses on measuring the cell-mediated immune (CMI) response, which involves T-cells. CMI is a crucial aspect of the body’s defense against certain diseases, indicating activation when detected. While most blood tests assess antibody production following exposure, the Tuberculosis Blood Test targets T-cells, which are essential for fighting bacterial infections. As a result, individuals who have received the bacillus Calmette-Guérin (BCG) TB vaccine or those infected with environmental mycobacteria typically yield negative results on this blood test.
Who Should Get Tested?
According to the Centers for Disease Control and Prevention (CDC), the following individuals should consider undergoing tuberculosis (TB) testing:
- Individuals who have close contact with patients at risk for TB, such as those working in nursing homes.
- People with compromised immune systems.
- Those arriving in the United States from countries with a high prevalence of TB, including regions like Latin America, the Caribbean, Africa, Asia, Eastern Europe, and Russia.
- Individuals who have been in contact with someone diagnosed with TB.
- People who use illegal drugs.
- Individuals experiencing symptoms of TB, such as fever, cough, and weight loss.
- Healthcare professionals.
When Is The QuantiFERON Test Recommended?
The QuantiFERON test is advisable for individuals who have previously received the Bacillus Calmette–Guérin (BCG) vaccine or those who may find it challenging to return for a follow-up appointment to evaluate TB skin test reactions.
What To Expect During The QuantiFERON Test?
Initially, a blood sample is collected using a needle and tube. The sample is then analyzed in a laboratory, with the results subsequently communicated to your physician.
This test assesses an individual’s immune response to Mycobacterium tuberculosis, specifically detecting the secretion of interferon-gamma by white blood cells when exposed to the TB bacterial antigen.
How To Interpret QuantiFERON Test Results:
- Positive: Suggests TB infection, prompting further investigations to determine whether the infection is active or latent. Additional assessments, such as physical examination and chest X-ray, assist in diagnosing the type of infection, guiding subsequent treatment plans.
- Negative: Indicates that active or latent infection is unlikely.
How Often Should QuantiFERON Testing Occur?
You can repeat the test at any time.
What To Expect After The Test
After you provide your specimen, it generally takes few business days to process and release your test results. Your test results will be available in a clear and easy-to-read report. Independent physicians are available to discuss questions or concerns you may have regarding your results.
