Home›TB Gold Quantiferon

Content created by

Written by

BDS, MDS - Oral and Maxillofacial Pathology

Reviewed by

Dr. Ashish Ranjan

MBBS, MD (Pharmacology)

Want to know more?
Read our Editorial Policy

TB Gold Quantiferon

Also known as TB Gold IGRA, Gamma Interferon For TB

₹2620~~₹2800~~ 6% Off

You need to provide

Blood

This test is for

Male, Female

Test Preparation

No special preparation is required.

Understanding TB Gold Quantiferon

What is TB Gold Quantiferon?

The 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.

The 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. The 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, the 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 the 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?

The 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

Positive

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?

The TB Gold Quantiferon test is the most accurate way to measure your TB risk. The test checks for the presence of Mycobacterium tuberculosis (TB) and helps you understand your risk for TB. Quantiferon TB Gold Test is a polymerase chain reaction (PCR) test and takes about two hours to complete.

Q. When should one get the Quantiferon TB Gold test?

It is usually recommended for people who have a high risk of tuberculosis, such as people who are HIV positive or have other diseases that make them more likely to develop tuberculosis.

Q. What happens if the TB Gold Quantiferon test result is positive?

If the TB Gold Quantiferon test results are positive, it indicates that there is a high possibility that you were exposed to tuberculosis and that you may have latent tuberculosis infection. However, your doctor may order several more tests to differentiate between active or latent TB.

Q. What happens if TB is not treated timely?

TB can lead to numerous health complications when not treated timely. These complications may include infection or damage to the joints, bones, spinal cord, brain, or lymph nodes, liver problems, kidney problems, and inflammation of tissues around the heart.

Q. How does tuberculosis spread?

Tuberculosis can spread when a person with the disease coughs, sneezes or sings. This can put tiny droplets of germs into the air. Then another person can breathe in the droplets, and the germs enter the lungs.

Q. What is Latent TB infection?

Latent tuberculosis infection (LTBI) is a state of continuous immune system response to the antigens of Mycobacterium tuberculosis. In this, the body continuously fights with these bacteria to control their growth. As a result, the body does not show any evidence of clinically manifested active TB. This condition makes it difficult to diagnose as the person does not feel ill and does not show signs of active TB disease. However, this infection can show its effect and may develop into an active TB disease in the future.