TB Gold Quantiferon
Understanding TB Gold Quantiferon
What is TB Gold Quantiferon?
A TB Gold Quantiferon test helps detect a latent tuberculosis infection (LTBI) or an active tuberculosis (TB) disease. This test is suggested if you have symptoms of TB, such as persistent cough, fever, and sudden weight loss. It is particularly valuable for individuals who have had recent exposure to TB, healthcare workers, and those with a higher risk of TB infection.
Tuberculosis is an infection that most often affects the lungs and is caused by a bacteria called mycobacterium tuberculosis. An active TB infection is when the affected individual is experiencing TB symptoms. However, latent infection is when the TB organism is present in the individual’s body, but there are no symptoms. People with latent TB infection are not infectious and cannot spread the infection to others. However, if left untreated, this individual may develop an active infection in the future and may be able to transmit the disease.
A TB Gold Quantiferon test, also called QuantiFERON-TB Gold (QFT-G), is a modern alternative to the tuberculin skin test (TST). It assesses the specific immune response to TB, providing a more specific and sensitive analysis than the TST. A TB Gold Quantiferon test may be helpful for individuals who have been in close contact with someone with active TB, those with a history of travel to or residence in TB-endemic regions, and individuals with a weakened immune system. It is also used for healthcare workers and in TB screening programs.
A positive result is a strong indicator of TB infection. However, a TB Gold Quantiferon test cannot distinguish between active and latent TB infection and, therefore, is used in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations.
Usually, no special preparation is required for a TB Gold Quantiferon test. The timing of the test can affect the accuracy of the results. If a person is tested too soon after exposure to tuberculosis bacteria, they may have a false negative result. Doctors recommend testing at least 6 to 8 weeks after the exposure to TB.
Test result ranges are approximate and may differ slightly between labs depending on the methodology and laboratory guidelines. Discuss your test reports with your doctor. Doctors may consider other factors, such as your health history, symptoms, medical conditions, and other test results, to establish a diagnosis of TB disease.
What is TB Gold Quantiferon used for?
A TB Gold Quantiferon test is done to:
- Detect tuberculosis (TB) in case you have been exposed.
- To screen individuals at higher risk of TB, such as healthcare workers, individuals with recent exposure to TB, and those from regions with a high prevalence of TB.
- To monitor individuals on immunosuppressive therapy since they have a high risk of progression of latent TB infection into active TB.
What does TB Gold Quantiferon measure?
A Quantiferon TB Gold Test is conducted to detect the presence of Mycobacterium tuberculosis, the tuberculosis (TB) causing bacteria in an individual’s body. This test helps determine whether a person has a tuberculosis infection or not. It measures the release of interferon-gamma (IFN-γ), a substance produced by T cells in response to TB antigens. It assesses the specific immune response to TB, providing a more targeted and accurate result than the TST.
Interpreting TB Gold Quantiferon results
Interpretations
|
NIL TUBE in IU/mL |
ANTIGEN TUBE MINUS NIL TUBE in IU/mL |
FINAL RESULT |
INTERPRETATION |
|
< = 8.00 |
<0.35 > = 0.35 & <25% of Nil tube > = 0.35 & > = 25% of Nil tube |
Negative Negative Positive |
M. tuberculosis infection unlikely M. tuberculosis infection unlikely M. tuberculosis infection likely |
|
>8.00 |
Any result |
Indeterminate |
This may be due to excessive levels of circulating gamma interferon or the presence of heterophile antibodies. |
Answers to Patient Concerns & Frequently Asked Questions (FAQs) about TB Gold Quantiferon
Frequently Asked Questions about TB Gold Quantiferon
Q. What is the TB Gold Quantiferon test?
Q. When should one get the Quantiferon TB Gold test?
Q. What happens if a TB Gold Quantiferon test result is positive?
Q. What happens if TB is not treated timely?
Q. How does tuberculosis spread?
Q. What is Latent TB infection?
Q. Can tuberculosis be cured?
Book TB Gold Quantiferon at-home
References
- Babu K, Philips M, Subbakrishna DK. Perspectives of Quantiferon TB Gold test among Indian practitioners: a survey. J Ophthalmic Inflamm Infect. 2013 Jan 11;3(1):9. [Accessed 26 Oct. 2023]. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3605069/
- Franken WP, Timmermans JF, Prins C, Slootman EJ, Dreverman J, Bruins H, van Dissel JT, Arend SM. Comparison of Mantoux and QuantiFERON TB Gold tests for diagnosis of latent tuberculosis infection in Army personnel. Clin Vaccine Immunol. 2007 Apr;14(4):477-80. [Accessed 26 Oct. 2023]. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1865601/ this Page
- Adigun R, Singh R. Tuberculosis. [Updated 2023 Jul 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441916/
- Tuberculosis [Internet]. WHO; 21 Apr. 2023 [Accessed 26 Oct. 2023]. Available from: https://www.who.int/news-room/fact-sheets/detail/tuberculosis#:~:text=Overview,Tuberculosis%20is%20preventable%20and%20curable.
- Basic TB Facts [Internet]. CDC; 20 Mar. 2016 [Accessed 26 Oct. 2023]. Available from: https://www.cdc.gov/tb/topic/basics/default.htm
- Narasimhan P, Wood J, Macintyre CR, Mathai D. Risk factors for tuberculosis. Pulm Med. 2013;2013:828939. [Accessed 26 Oct. 2023]. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3583136/#:~:text=However%20at%20the%20population%20level,accelerate%20progression%20to%20TB%20disease.
- TB Screening (Whole Blood) [Internet]. Rochester, NY: University of Rochester Medical Center; [Accessed 26 Oct. 2023]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid=tb_screen_blood
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