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Dr. Ashish Ranjan

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Tuberculosis Gold Interferon Gamma Release Assay

(TB Gold IGRA)

₹2650

This test is for

Male, Female

Test Preparation

No special preparation required

Understanding Tuberculosis Gold Interferon Gamma Release Assay

What is Tuberculosis Gold Interferon Gamma Release Assay?

TB Gold / Gamma Interferon, also called QuantiFERON-TB Gold (QFT-G), is a screening test done to diagnose for Tuberculosis (TB). This test is suggested if you have symptoms of TB such as persistent cough, fever, and sudden weight loss. People who are at high risk for developing TB are those with HIV infection, weakened immune system, and advanced age. It may also affect those not treated properly for TB in the past.

QFT is a modern alternative to the tuberculin test. It provides highly specific and sensitive analysis of the condition. A positive result is a strong indicator of TB infection. However, this test cannot distinguish between active and latent TB infection.

What is Tuberculosis Gold Interferon Gamma Release Assay used for?

This test is mostly recommended to :

Young age children, elderly people and immunocompromised patients, since they have a high risk of progression of LTBI into active TB.
People who are in close contact with the TB infected patients,
Health care professionals taking care of TB patients
People residing in high-risk settings such as near health care facilities or nursing homes etc.

What does Tuberculosis Gold Interferon Gamma Release Assay measure?

Latent tuberculosis infection (LTBI) is a non-communicable asymptomatic condition that can persist for many years and may progress to tuberculous disease in the future. The main aim of diagnosing LTBI is to analyze the condition and suggest a medical treatment to prevent the disease. This test measures the response of the immune system towards the antigens produced by the mycobacterial proteins.

A positive result indicates that mycobacterium tuberculosis infection is likely to happen but to confirm the diagnosis further medical evaluation is necessary.

This test is usually negative in individuals vaccinated with Mycobacterium bovis BCG.

Interpreting Tuberculosis Gold Interferon Gamma Release Assay 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 Tuberculosis Gold Interferon Gamma Release Assay

Frequently Asked Questions about Tuberculosis Gold Interferon Gamma Release Assay

Q. How is the blood sample taken?

The healthcare provider takes a blood sample from the arm. The site from where the blood is to be withdrawn is cleaned with a swab of rubbing alcohol. This is then followed by inserting a small needle which has a tube attached to it for collecting blood. Once the sufficient blood for analysis is withdrawn, the needle is removed. The site is then covered with a gauze pad.

Q. Is there any risk associated with the withdrawal of blood sample procedure?

As such there is no risk but in few cases, bruising, bleeding, and infection at the puncture site can be seen. In very few cases, there can be swelling of the vein after the blood is withdrawn.

Q. How does it work?

Step 1: Provide a saliva sample and send to the lab. Pre-paid envelope included. Step 2: Receive your easy-to-read report in 3 to 4 weeks. Step 3: Talk to our genetic counselor about a personalized health plan for you and your family.

Q. What is Latent TB infection?

Latent tuberculosis infection (LTBI) is a state of continuous immune system response to the antigens of Mycobacterium tuberculosis antigens. In this, the body continuously fights with these bacteria in order 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.

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