Understanding the TB Gold Quantiferon Test
Alternative Names:
Interferon-gamma (IFN-gamma)
Interferon-gamma release assay (IGRA)
TB Gold
QFT Gold Test
Latent tuberculosis infection (LTBI) Test
What It Is: The TB Gold Quantiferon test, also known as the Quantiferon-TB Gold test, is a blood test used to detect tuberculosis (TB) infection. It measures the immune system's response to TB bacteria by detecting the release of interferon-gamma (IFN-gamma) in response to TB antigens.
Why It's Done:
Diagnosing TB Infection: The primary purpose of the TB Gold Quantiferon test is to diagnose latent or active tuberculosis infection.
Screening: It is often used to screen individuals who may have been exposed to TB, such as healthcare workers, immigrants, or people living in high-risk areas.
Monitoring Immune Response: The test can help monitor the immune response to TB infection, especially in individuals with a history of TB exposure or infection.
How the Test Works:
Blood Sample Collection: A blood sample is drawn from the patient.
Exposure to TB Antigens: The blood sample is exposed to TB antigens in a laboratory setting.
Measurement of IFN-gamma: The test measures the amount of interferon-gamma (IFN-gamma) released by the immune cells in response to the TB antigens.
Results: The results indicate whether the immune system has been exposed to TB bacteria.
Understanding the Results:
Positive Result: Indicates that the immune system has been exposed to TB bacteria, suggesting a TB infection.
Negative Result: Indicates that the immune system has not been exposed to TB bacteria, suggesting no TB infection.
Why Your Doctor Might Order This Test:
Symptoms of TB: If you have symptoms such as a persistent cough, fever, night sweats, weight loss, or blood in your sputum, this test can help diagnose TB.
Exposure to TB: If you have been in close contact with someone who has TB, this test can help determine if you have been infected.
Screening: For individuals at high risk of TB exposure, such as healthcare workers or immigrants.
Symptoms That Might Prompt This Test:
Persistent cough lasting more than three weeks
Chest pain
Coughing up blood or sputum
Unexplained weight loss
Fatigue and weakness
Night sweats
Lifestyle and Management: Depending on your results, your healthcare provider might recommend further tests, treatments, or lifestyle changes to manage TB effectively. Regular monitoring and follow-up are essential for successful treatment.