QuantiFERON®-TB Gold Plus (TB Test) Most Popular

The QuantiFERON®-TB Gold Plus (TB Test) test contains 1 test with 5 biomarkers.

Brief Description: The Quantiferon TB Gold Plus test is a blood test that helps detect tuberculosis (TB). It measures the body's immune response to the bacteria called Mycobacterium tuberculosis, which causes TB. This test is often preferred over the traditional TB skin test because it only requires one blood test and tends to be more accurate, especially in people who have received the BCG vaccine. Additionally, you can conveniently order this test from your home, making it easier to access.

Also Known As: TB Test, Tuberculosis Test, IGRA Test, Interferon-Gamma Release Assay Test.

Specimen Type: Whole Blood

Test Preparation: No preparation required

When and Why You Might Order a Quantiferon TB Gold Plus Test

You might consider ordering a Quantiferon TB Gold Plus test for yourself in these scenarios:

Screening for Latent TB Infection: This test is useful if you think you’ve been exposed to TB or if you're at increased risk of infection. It’s particularly recommended for individuals who have been in close contact with someone diagnosed with TB, those working in healthcare settings, and immigrants from areas where TB is more prevalent.

Diagnosis of Active TB: If you’re experiencing symptoms like a persistent cough, fever, weight loss, and night sweats, this test can be ordered to help determine if these are due to active TB.

Ordering this test directly can be a proactive step in managing your health, providing a quick and reliable result without multiple visits to healthcare facilities. It’s a convenient option that allows you to take timely action based on the results.

What the Quantiferon TB Gold Plus Test Checks For:

Tuberculosis (TB) is a disease that spreads through the air, caused by the bacteria called M. tuberculosis complex. When someone is infected, they might develop active TB disease quickly, or they might have Latent TB Infection (LTBI). LTBI doesn't show symptoms and can't spread to others, but it's still important to diagnose because treatment can prevent it from turning into active TB. Before, the only way to check for LTBI was through a skin test.

The Quantiferon TB Gold Plus test is a blood test that has several advantages. It doesn't give false positives from past vaccinations for TB or from exposure to non-TB bacteria, which is a problem with the skin test. Also, this test is consistent and doesn't change depending on the person’s reaction to the testing material, and it doesn't require a second visit to check the results.

Compared to the skin test, the TB blood test is usually more accurate and only needs one trip to the lab. This makes it easier and less time-consuming than going back to the doctor's office several times, which is necessary for the skin test.

Conditions or Diseases Requiring a Quantiferon TB Gold Plus Test

The Quantiferon TB Gold Plus test is mainly used for:

Screening for Latent TB Infection: This test checks if someone who might have been near TB or is at a higher risk has a hidden TB infection. This includes people who live close to someone with active TB, health care workers, and people from places where TB is more common.

Diagnosis of Active TB: This test is used to help find out if someone has active TB, especially when they show signs like a bad cough, feeling tired, or losing weight, which could mean they have TB.

Utilization of Quantiferon TB Gold Plus Test Results by Health Care Providers

Health care providers use the results of the Quantiferon TB Gold Plus test to:

1. Identify Latent TB Infection: A positive result indicates exposure to TB bacteria and the presence of a latent infection, requiring further evaluation and possible treatment to prevent the development of active TB disease.

2. Support Diagnosis of Active TB: A positive result, along with other clinical findings, assists in confirming the diagnosis of active TB, prompting initiation of appropriate treatment and infection control measures.

3. Guide Treatment Decisions: The test results, in combination with other diagnostic information, help determine the need for TB treatment, the duration of treatment, and the choice of specific anti-TB medications.

It's important to note that the interpretation of Quantiferon TB Gold Plus test results should consider the individual's clinical history, risk factors, and exposure history. Consultation with a health care provider experienced in TB management is essential for accurate interpretation and appropriate patient care.

Other Lab Tests Ordered alongside a Quantiferon TB Gold Plus Test

When a QuantiFERON TB Gold Plus test is ordered, it might be part of a broader evaluation for tuberculosis or other related health issues. Here are some tests commonly ordered alongside it:

1. Complete Blood Count (CBC):

   • Purpose: Provides a broad picture of overall health, including red and white blood cells and platelets.
   • Why Is It Ordered: To assess general health status and detect signs of infection or other health issues that may be relevant in the context of TB diagnosis or treatment.

2. Liver Function Test:

   • Purpose: To assess liver health.
   • Why Is It Ordered: Certain medications used in the treatment of TB can affect liver function, so baseline and ongoing liver function tests are important.

3. Kidney Function Test:

   • Purpose: To evaluate kidney function.
   • Why Is It Ordered: To ensure that kidney function is adequate, especially considering that some TB medications can affect kidney health.

4. Blood Glucose and Hemoglobin A1c (HbA1c):

   • Purpose: To assess blood sugar control, particularly in individuals with diabetes.
   • Why Is It Ordered: Diabetes can increase the risk of developing active TB and can affect the management of TB treatment.

These tests, when ordered alongside a QuantiFERON TB Gold Plus test, provide a comprehensive view of an individual’s health status in relation to TB infection and are critical for diagnosing, managing, and monitoring tuberculosis. The specific combination of tests will depend on the individual's risk factors, symptoms, and overall health condition.

Most Common Questions About the QuantiFERON TB Gold test:

Understanding the QuantiFERON-TB Gold Test

What is the QuantiFERON-TB Gold Test?

The QuantiFERON-TB Gold test, also known as QFT-GIT, is a blood test that checks for Mycobacterium tuberculosis, the bacteria that causes tuberculosis (TB). It measures how your immune system reacts to TB proteins to see if you have been infected with TB bacteria.

Why is the QuantiFERON-TB Gold Test Performed?

This test is used to screen people who might be at risk for TB or who might have been exposed to TB. People who often get this test include health care workers, immigrants from places where TB is common, and those living close to someone who has TB.

TB Infection and Its Implications

What's the difference between latent TB infection and TB disease, and how does the QuantiFERON-TB Gold test fit in?

Latent TB infection means you have TB bacteria in your body, but they are not active, so you don't feel sick and can't spread TB to others. TB disease means the bacteria are active and can make you feel sick. The QuantiFERON-TB Gold test can find both conditions by checking if TB bacteria are in your body, whether they are active or not.

If my QuantiFERON-TB Gold test is positive, does it mean I have TB disease?

No, a positive result from this test only means you have been infected with TB bacteria. It does not tell if the infection is latent or has turned into TB disease. More tests, like a chest x-ray and sputum culture, are needed to see if it is TB disease.

What happens if I have a positive QuantiFERON-TB Gold test but no symptoms of TB?

If your test is positive but you don't have symptoms, you probably have latent TB infection. You can't spread TB to others, but doctors usually recommend treatment to stop the latent infection from becoming active TB disease.

Understanding Test Results

How are the results of the QuantiFERON-TB Gold test interpreted?

The results of the QFT-GIT are usually reported as positive, negative, or indeterminate. A positive result indicates TB infection, a negative result indicates no infection, and an indeterminate result suggests the test couldn't conclusively determine your TB status, possibly due to a lab error or immune system suppression.

Can the QuantiFERON-TB Gold test yield false positive or false negative results?

Yes, false positives can occur if the immune system reacts to the test despite the absence of TB bacteria. False negatives can occur if the immune system fails to react to the test despite the presence of TB bacteria, which can happen in people with weakened immune systems.

What should I do if my QuantiFERON-TB Gold test results are indeterminate?

Indeterminate results usually require retesting. They can occur if your immune system response is insufficient to give a clear result, often due to immune system suppression or lab error.

Health Implications and the QuantiFERON-TB Gold Test

What health implications are associated with a positive QuantiFERON-TB Gold test result?

A positive QFT-GIT result indicates that you've been infected with TB bacteria. This puts you at risk for developing TB disease, especially if your immune system becomes weakened. It's essential to consult with your healthcare provider for potential treatment to prevent the infection from becoming active.

Can the QuantiFERON-TB Gold test detect TB in people with HIV?

Yes, the QFT-GIT can detect TB infection in people with HIV. However, the test's sensitivity might be reduced in individuals with HIV, particularly those with advanced immune suppression.

The QuantiFERON-TB Gold Test in Medical Practice

How often should I get a QuantiFERON-TB Gold test?

The frequency of testing depends on your risk of TB exposure. High-risk individuals, like healthcare workers in settings where TB is prevalent, might need routine annual testing. If you're not at high risk, retesting is usually only needed if you believe you've been exposed to TB bacteria.

Can the QuantiFERON-TB Gold test be used in children?

Yes, the QFT-GIT can be used in children over the age of two. However, it's not as sensitive in young children compared to adults, so additional testing might be necessary.

Further Insights into the QuantiFERON-TB Gold Test

Why would I choose a QuantiFERON-TB Gold test over a TB skin test?

The QuantiFERON-TB Gold test, or QFT-GIT, has several benefits compared to the skin test. It only requires one visit to the doctor, is less likely to give a false positive result if you've had the Bacillus Calmette-Guérin (BCG) vaccine, and it doesn't depend on your own judgment to read the results.

If I've had the BCG vaccine, will the QuantiFERON-TB Gold test give a false positive?

No, the QFT-GIT is not affected by the BCG vaccine, so it is unlikely to give a false positive result because of the vaccine.

Can the QuantiFERON-TB Gold test detect drug-resistant TB?

No, the QFT-GIT can only tell if TB bacteria are present, not if they are resistant to drugs.

How does pregnancy affect the results of the QuantiFERON-TB Gold test?

Being pregnant does not usually change the results of the QFT-GIT. If you are pregnant and at risk for TB, you might still be advised to get tested.

What impact do immunosuppressive medications have on the QuantiFERON-TB Gold test results?

Drugs that suppress the immune system, like corticosteroids or medications for autoimmune diseases or organ transplants, can make the immune response weaker. This might lead to a false negative result from the QFT-GIT.

Can the QuantiFERON-TB Gold test tell if I'm contagious?

No, the QFT-GIT can't tell if you're contagious. It only shows if you have a TB infection. More tests, like a sputum culture, are needed to see if you have active TB disease and are contagious.

Can the QuantiFERON-TB Gold test check how well TB treatment is working?

No, the QFT-GIT is not used to monitor TB treatment because it can't tell the difference between active and latent TB. The immune response it detects might stay the same even after you've been successfully treated.

What factors can make the QuantiFERON-TB Gold test less accurate?

Things like lab mistakes, incorrect blood handling, recent TB exposure (less than 8 weeks ago), being very young (under 2 years old), and having a weakened immune system can all make the QFT-GIT less accurate.

Can the QuantiFERON-TB Gold test detect TB meningitis?

No, the QFT-GIT can't specifically find TB meningitis. While it detects TB infection, it doesn’t show where the infection is in your body. TB meningitis is usually diagnosed with other tests, like a lumbar puncture.

How do other health conditions affect the QuantiFERON-TB Gold test results?

Health conditions that weaken your immune system, like HIV, some cancers, or autoimmune diseases, can affect the results of the QFT-GIT. These conditions might cause a false negative result.

Can the QuantiFERON-TB Gold test diagnose infections caused by non-tuberculous mycobacteria (NTM)?

No, the QFT-GIT is only designed to detect Mycobacterium tuberculosis, the bacteria that cause TB, not other types of mycobacterial infections.

What should I do if I think I've been exposed to TB, but my QuantiFERON-TB Gold test is negative?

If you believe you've been exposed to TB recently (within the last 8 weeks) and your test is negative, talk to your doctor. Sometimes, the test might be negative if your immune system hasn’t reacted to the bacteria yet. You might need to be tested again.

What does a negative QuantiFERON-TB Gold test result mean for my health?

A negative result usually means you don't have a TB infection, lowering your risk of developing TB disease. However, no test is perfect. There's a small chance of a false negative, especially if your immune system is weak or if you were recently infected.