Tuberculosis Test

Why should I get the QuantiFERON-TB Gold test?

This test is right for anyone who is worried they may have been exposed to Tuberculosis. If you know anyone that has tuberculosis, have visited or lived in any country where Tuberculosis is present, if you were born in any country where Tuberculosis is prevalent or if you are unsure if you received the Tuberculosis (BCG) vaccine, then you should consider getting this test.

What is Tuberculosis?

Tuberculosis (TB) is a bacterial infection that usually affects the lungs, but can spread to other parts of the body:

TB is caused by the bacterium Mycobacterium tuberculosis. It's spread through the air when an infected person coughs, sneezes, or spits.

Symptoms of Tuberculosis include:

• A cough that lasts more than three weeks, with or without mucus or blood
• Feeling tired or exhausted
• High temperature or night sweats
• Loss of appetite
• Weight loss
• Chest pain, especially when breathing in

TB is usually treated with antibiotics and can be fatal without treatment.

What is the QuantiFERON-TB Gold test?

QuantiFERON-TB Gold (QFT) is a simple blood test to test you for Tuberculosis infection. QuantiFERON-TB Gold is an interferon-gamma (IFN-γ) release assay, commonly known as an IGRA, and is a modern alternative to the tuberculin skin test (TST, PPD or Mantoux). Unlike the TST, theQuantiFERON test is a controlled laboratory test that requires only one patient visit and is unaffected by previous Bacille Calmette-Guerin (BCG) vaccination.

Is the QuantiFERON-TB Gold test good?

The QuantiFERON-TB Gold test is highly specific and sensitive: a positive result is strongly predictive of true infection with M. tuberculosis.

The US Centers for Disease Control (CDC) Guidelines recommend the use of QuantiFERON-TB Gold test in all situations in which the Tuberculin Skin Test was historically used, with IGRAs being the preferred test for persons who have been BCG vaccinated.

The QuantiFERON-TB Gold test offers:

• The most accurate and reproducible results for Tuberculosis infection
• The confidence of more than 1200 clinical and scientific studies
• The QFT test is not affected by a previous BCG vaccination, and it only requires one visit to a laboratory.
• Convenient and objective ELISA technology
• Single visit testing

How does the QuantiFERON-TB Gold test work?

The test measures the release of interferon-gamma from T cells in response to synthetic polypeptides specific to M. tuberculosis. The QuantiFERON-TB Gold (QFT) The QFT test kit consists of four sample tubes which are lined either with the TB antigens ESAT-6, CFP-10 or with control substances that enable any reaction to be measured and analysed. When a blood sample is taken from an individual with latent or active TB infection it contains T cells that are only present in a person with a current infection. These T cells are not present in the blood of individuals who are not infected or who have recovered from TB in the past. When these TB specific T cells come into contact with the TB antigens lining the QFT sample tubes they release the cytokine Interferon-gamma (IFN- γ). The QFT test measures the level of Interferon-gamma (IFN- γ) in the blood sample and from this the likelihood of current TB infection is calculated.

What are the QuantiFERON-TB Gold test limitations?

The QFT test can't distinguish between latent and active TB, and it's not suitable for people who are immunocompromised or taking immunosuppressive drugs.

What Samples will be collected for my QuantiFERON-TB Gold test?

A blood sample is collected from your arm into special tubes. These tubes will be sent to our laboratory for fast analysis.

What will my results mean?

The QFT test can produce negative, positive, or indeterminate results. A positive result is strongly predictive of a true tuberculosis infection.

Description provided by Better2Know.