TB Gold - IGRA (Interferon-y Gamma release assay) - 3 tube, Lithium Heparin Blood

What is the IGRA Test (Interferon Gamma Release Assay)?

The Interferon Gamma Release Assay (IGRA) test is a modern blood test used to detect latent tuberculosis (TB) infection. It measures the immune system’s release of interferon-gamma (IFN-γ) when exposed to Mycobacterium tuberculosis-specific antigens.

Unlike the traditional Tuberculin Skin Test (TST), the IGRA test does not require multiple visits and is not affected by prior BCG vaccination, making it a more accurate method for identifying latent TB.

The IGRA test cannot directly diagnose active TB disease but indicates whether the person has been infected with TB bacteria at any point.

What Does an IGRA Test Measure?

The IGRA test quantifies interferon-gamma (IFN-γ) released by T-cells in the blood after exposure to TB-specific antigens.

It helps:

• Detect TB infection: Determines if you’ve been exposed to TB bacteria.
• Differentiate latent from BCG-induced immunity: Distinguishes true infection from BCG vaccination response.
• Evaluate immune response: Especially useful in immunocompromised or high-risk individuals.
• Support contact tracing: Identifies infection in people exposed to confirmed TB cases.
• Guide preventive therapy: Helps decide if preventive anti-TB treatment is needed to avoid active disease.

IGRA Test: Who Needs It and Why It’s Done

What Symptoms May Call for an IGRA Test (Interferon Gamma Release Assay)?

The IGRA test is recommended for:

• Individuals exposed to someone with active TB.
• Healthcare professionals and lab workers handling TB cases.
• People planning organ transplants or receiving immunosuppressive therapy.
• Patients with HIV/AIDS, diabetes, or kidney failure.
• People previously vaccinated with BCG but requiring TB screening.
• Children and adults in high TB prevalence areas.
• Individuals undergoing pre-employment or immigration health checks.

Why is an IGRA Test (Interferon Gamma Release Assay) Done?

• The IGRA test plays a crucial role in identifying latent tuberculosis infection (LTBI) — a condition where TB bacteria are present but inactive.
• People with latent TB show no symptoms and are not contagious, but the infection can reactivate if their immune system weakens.
• Early detection and preventive treatment significantly reduce the risk of developing active TB.
• The test’s accuracy and convenience make it ideal for large-scale screening programs and clinical settings.

Importance of IGRA Test (Interferon Gamma Release Assay)

The IGRA test plays a crucial role in identifying latent tuberculosis infection (LTBI) — a condition where TB bacteria are present but inactive. People with latent TB show no symptoms and are not contagious, but the infection can reactivate if their immune system weakens.

Early detection and preventive treatment significantly reduce the risk of developing active TB. The test’s accuracy and convenience make it ideal for large-scale screening programs and clinical settings.

IGRA Test Booking & Reports – Metropolis Healthcare India

How to Book an IGRA Test (Interferon Gamma Release Assay)?

1. Simple Online Booking
   Book your IGRA test through the Metropolis Healthcare website or app. Choose your nearest lab or request home sample collection.
2. Safe Home Sample Collection
   Our skilled professionals collect your blood sample at home, following strict hygiene and safety protocols.
3. Accredited Testing
   Samples are processed in NABL & CAP accredited laboratories using advanced Enzyme Immunoassay (EIA) technology.
4. Fast & Accurate Reporting
   Receive precise reports the next day by 8:00 PM. Access your results via email, WhatsApp, or directly from the Metropolis app or website.

Is Home Sample Collection for IGRA Test (Interferon Gamma Release Assay) Available Near You?

Yes. Metropolis Healthcare provides safe, hygienic home collection services. Your sample is handled carefully to maintain stability and test reliability.

In how much time will I get IGRA Test (Interferon Gamma Release Assay) report?

Receive precise reports the next day.
Note: Reporting time and cost may vary depending on your location.

Where can I see or get IGRA Test (Interferon Gamma Release Assay) results?

You can download your IGRA test report from the Metropolis Healthcare website or mobile app. Reports are also sent via email and WhatsApp, or you can collect a hard copy from your nearest lab.

Interpreting IGRA Test Results

What Your IGRA Test Results May Indicate
 

Note:

A positive result does not confirm active TB. Further tests such as chest X-ray, sputum microscopy, or GeneXpert MTB/RIF are needed for confirmation.
 

Understanding Abnormal IGRA Test (Interferon Gamma Release Assay) Results by Parameter

How Should You Prepare for an IGRA Test?

Provide complete clinical history; fasting not required

• Recent TB exposure (false negatives may occur within 8–10 weeks of infection).
• HIV infection or other conditions causing immune suppression.
• Recent viral infections (e.g., measles, influenza).
• Certain cancers or chronic diseases (e.g., diabetes, renal failure).
• Recent BCG vaccination.
• Technical issues in sample handling or delayed processing.

How Is an IGRA Test (Interferon Gamma Release Assay) Done? (Step-by-Step Procedure)

The test involves drawing a small amount of blood into three special tubes:

• Nil Tube: Serves as a negative control.
• Antigen Tube: Contains TB-specific antigens that trigger immune response.
• Mitogen Tube: Serves as a positive control to confirm immune reactivity.
• In the lab, white blood cells are exposed to TB antigens.
• If the body has been infected with TB, T-cells release interferon-gamma (IFN-γ), which is measured quantitatively using Enzyme Immunoassay (EIA).

Conditions That May Affect IGRA Test Accuracy

Factors That Can Affect IGRA Test Accuracy

• Recent TB exposure (false negatives may occur within 8–10 weeks of infection).
• HIV infection or other conditions causing immune suppression.
• Recent viral infections (e.g., measles, influenza).
• Certain cancers or chronic diseases (e.g., diabetes, renal failure).
• Recent BCG vaccination.
• Technical issues in sample handling or delayed processing.

Diseases That an IGRA Test (Interferon Gamma Release Assay) Can Help Detect

• Detects Mycobacterium tuberculosis infection.
• Helps diagnose latent TB infection.
• Differentiates infection from BCG vaccination response.
• Useful for screening immunocompromised individuals.
• Supports pre-transplant and occupational health screening.
• Assists in TB contact tracing and public health surveillance.
• Monitors response to anti-TB therapy in some cases.