QuantiFERON Gold Plus TB Test

QuantiFERON TB Gold Plus Test

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The most affordable QuantiFERON Gold Plus test in the United States. It is also the most accurate TB test you can buy online without a doctor's visit. The price includes the doctor's order. No hidden fees or suprise bills.

This is the gold standard for the IGRA TB test. The 1 Tube QuantiFERON®-TB Gold Plus is an indirect test for M. tuberculosis infection TB (including disease) and is intended for use in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations. This test does not differentiate between latent and active TB. All institutions, the US government, employers, and agencies accept this test.

Mastering the Quantiferon Gold Test: Essential Information

DiscountedLabs.com sells the most affordable QuantiFERON Gold Plus test in the United States. It is also the most accurate TB test you can buy online without a doctor's visit. The price includes the doctor's order. There are no hidden fees or surprise bills.

This is the gold standard for the IGRA TB test. The 1 Tube QuantiFERON®-TB Gold Plus is an indirect test for M. tuberculosis infection TB (including disease) and is intended for use in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations. This test does not differentiate between latent and active TB. All institutions, the US government, employers, and agencies accept this test.

The Ultimate Guide to Quantiferon Gold Test

The most affordable Quantiferon Gold Plus test in the United States. It is also the most accurate TB test you can buy online without a doctor's visit. The price includes the doctor's order. There are no hidden fees or surprise bills.

This is the gold standard for the IGRA TB test. The 1 Tube QuantiFERON®-TB Gold Plus is an indirect test for M. tuberculosis infection TB (including disease) and is intended for use in conjunction with risk assessment, radiography, and other medical and diagnostic evaluations. This test does not differentiate between latent and active TB. All institutions, the US government, employers, and agencies accept this test for the detection of M. tuberculosis infection.

Quantiferon Gold Test: The Gold Standard for TB Testing

Tuberculosis (TB) is a serious infectious disease that affects millions of people worldwide. Accurate and timely diagnosis is essential to preventing the spread of TB and ensuring that patients receive the appropriate treatment. In recent years, QuantiFERON-TB Gold Plus has emerged as a leading alternative to traditional TB tests such as the tuberculin skin test (TST). The QuantiFERON-TB Gold Plus test is a blood-based assay that detects the presence of TB-specific antigens in the blood. It offers several advantages over traditional TB tests, including higher sensitivity and specificity, a faster turnaround time, and no cross-reactivity with the Bacillus Calmette-Guérin (BCG) vaccine. In this blog post, we will explore how QuantiFERON-TB Gold Plus works, its advantages over other TB tests, and its practical aspects. We will also address common misconceptions about QuantiFERON-TB Gold Plus and debunk some myths surrounding it. Finally, we will discuss whether QuantiFERON-TB Gold Plus is the future of TB diagnosis.

Commercially Available IGRAs for M tuberculosis

The quantiferon tb gold plus test is one of the commercially available interferon-gamma release assays (IGRAs) used for the diagnosis of tuberculosis. This test is based on the principle that T-cells in the blood release interferon-gamma when exposed to specific antigens derived from Mycobacterium tuberculosis. The Quantiferon TB Gold Plus test, a modern alternative to the traditional tuberculin skin test, offers improved performance and quicker results, making it a valuable tool for screening individuals who are at high risk of developing M tuberculosis infection, such as healthcare workers, immigrants, and prisoners.

Understanding the Basics of QuantiFERON TB Gold Plus Test

QuantiFERON-TB Gold Plus is an advanced tuberculosis (TB) test that gauges the immune response to TB antigens. It uses interferon-gamma release assays (IGRAs) to find out when T cells release interferon-gamma when they are infected with MTB. This whole-blood assay, also known as an in vitro diagnostic test, necessitates a small blood sample for analysis. One of the best things about QuantiFERON-TB Gold Plus is that it can give you exact numbers by measuring how much interferon-gamma is made in response to MTB antigens. Moreover, this test offers a quicker alternative to traditional TB tests, as results are available within 24 hours. By understanding the basics of QuantiFERON-TB Gold Plus, healthcare professionals can gain valuable insights into the immune response to Mycobacterium tuberculosis infection and effectively diagnose both active and latent tuberculosis infections.

The Science Behind the QuantiFERON Gold Plus Test

To get the immune system to work, the Quantiferon Gold Plus test uses peptide antigens that are specific to the M tuberculosis complex, like ESAT-6 and CFP-10. These antigens are mixed with the patient's whole blood sample and then incubated for a specific amount of time. If the patient has been exposed to M. tuberculosis complex agents during this time, their T cells will release interferon-gamma in response to the antigens. This is called an in vitro response. The released interferon-gamma is then measured using an enzyme-linked immunosorbent assay (ELISA). Qft-git is a commonly used abbreviation for the QuantiFERON-TB Gold Plus test.

By measuring the amount of interferon-gamma, the QuantiFERON-TB Gold Plus test can determine whether there is a latent TB infection or active TB disease present. This test provides a more accurate and specific diagnosis compared to other traditional TB tests. The QuantiFERON-TB Gold Plus test can provide results within 24 hours, making it a faster alternative for quantitative measurements. A positive QFT result plays a crucial role in accurately diagnosing TB infections and aiding in treatment decisions.

How Does Quantiferon TB Gold Plus Test Work?

QuantiFERON TB Gold Plus works by measuring the immune response to TB antigens using a blood sample. The sample is divided into three tubes: a nil control, TB antigen tube, and a positive control mitogen tube. You can use ELISA to find out how much interferon-gamma T cells release when they come into contact with TB antigens and the mitogen phytohaemagglutinin in the positive control mitogen tube. The nil value in the nil control tube is used to find the baseline level of interferon-gamma when TB antigens are not present. This is done to account for any heterophile antibody effects or non-specific IFN-γ production that might lead to a false-positive result on the test.

Interpreting a QuantiFERON TB Gold Plus Test Result

A positive test result from the QuantiFERON-TB Gold Plus indicates the presence of either a latent TB infection or active TB disease. On the other hand, a negative test result suggests the absence of a tuberculosis infection. However, it is important to note that an indeterminate result might occur due to issues with blood collection, handling, or laboratory procedures, as well as potential infection with nontuberculous mycobacteria. Therefore, it is crucial for a healthcare professional to interpret the test results in conjunction with the patient's medical history and other diagnostic information. In cases where the result is positive or indeterminate, additional tests, such as chest X-rays or sputum cultures, should be conducted to further evaluate the condition. This comprehensive approach ensures accurate diagnosis and appropriate treatment decisions. If a patient has a high suspicion of exposure to tuberculosis or nontuberculous mycobacteria, a negative test should be repeated to confirm the result. A positive test indicates infection with Mycobacterium tuberculosis, while a negative test may be due to exposure to other types of Mycobacterium.

Advantages of Quantiferon Gold Test over Other TB Tests

QuantiFERON-TB Gold Plus offers several advantages over other TB tests. Firstly, it has higher specificity compared to the tuberculin skin test (TST) in populations vaccinated with Bacillus Calmette-Guérin (BCG). This means that QuantiFERON-TB Gold Plus is less likely to produce false-positive results in individuals who have received the BCG vaccine. Additionally, QuantiFERON-TB Gold Plus eliminates the need for a second patient visit as the blood sample can be collected and processed at a convenient time. This saves both time and effort for patients and healthcare providers.

Furthermore, QuantiFERON-TB Gold Plus is unaffected by prior BCG vaccination, lowering the possibility of false-positive results. The test also shows improved specificity, as it does not cross-react with most non-tuberculosis mycobacteria. This ensures the more accurate detection of TB infections. Another advantage of Quantiferon Gold Test is that it provides quantitative results, allowing for a more objective interpretation. These quantitative results provide additional information for healthcare professionals to assess the severity of the infection and guide appropriate treatment decisions. Overall, QuantiFERON-TB Gold Plus offers significant advantages over other TB tests, providing more accurate and convenient testing options for the detection of TB infection.

Comparison of Sensitivity and Specificity between QuantiFERON TB Gold Plus and Other TB Tests

QuantiFERON Gold Plus has been found to have comparable sensitivity to the TST in detecting latent TB infection. However, it offers a higher specificity, especially in populations that have been vaccinated with BCG. Comparing QuantiFERON-TB Gold Plus to other interferon-gamma release assays (IGRAs), it has shown better sensitivity and specificity. The test exhibits better agreement with the presence of TB disease compared to the TST. Additionally, QuantiFERON-TB Gold Plus provides greater reliability and lower rates of false-positive results. Its higher specificity reduces the chances of false-positive results, making it a valuable tool in accurately identifying individuals with TB infection, including those co-infected with HIV. This is particularly important in regions where BCG vaccination is prevalent or in healthcare settings where distinguishing between latent TB infection and active tuberculosis disease is crucial. QuantiFERON-TB Gold Plus offers an advanced diagnostic option for detecting and monitoring Mycobacterium tuberculosis infection, aligning with the World Health Organization's strategy of targeting latent tuberculosis infection for disease control globally.

Detection of Active and Latent TB Infection

QuantiFERON-TB Gold Plus can effectively detect both active and latent TB infections. A positive result indicates either a current active TB infection or a previous exposure to TB resulting in latent infection. However, it is important to note that the presence of active TB disease should always be confirmed using additional diagnostic tests such as sputum cultures and chest X-rays. This ensures an accurate diagnosis and appropriate treatment.

In the case of latent TB infection, if left untreated, there is a risk of it progressing to active TB disease. This highlights the importance of identifying and treating individuals with LTBI-latent TB infection. QuantiFERON-TB Gold Plus plays a crucial role in identifying individuals at risk of developing active disease. Using interferon-gamma release assays (IGRAs) like QuantiFERON-TB Gold Plus, doctors can accurately find out how common latent TB infection is and take the right steps to stop it from turning into active tuberculosis disease. The use of QuantiFERON-TB Gold Plus has been validated in several studies published in the Journal of Clinical Microbiology (J Clin Microbiol).

Understanding Indeterminate Responses in QuantiFERON-TB Gold Plus

Indeterminate responses in QuantiFERON-TB Gold Plus may occur due to issues with blood collection, handling, or laboratory procedures. Certain medical conditions, such as immunosuppression, can also lead to indeterminate results. An indeterminate result means that the test could not provide a definitive positive or negative outcome. Individuals with indeterminate results should be retested to obtain a valid interpretation. Repeat testing should follow proper blood collection and processing protocols. It is important to address these indeterminate responses to ensure accurate and reliable results from the QuantiFERON-TB Gold Plus test. By understanding the factors that can contribute to an indeterminate result, healthcare providers can take the necessary steps to minimize these occurrences and ensure accurate diagnosis and monitoring of tuberculosis infections.

Does Prior Vaccination or Testing Affect a QuantiFERON TB Gold Plus Result?

When compared to the TST, QuantiFERON-TB Gold Plus offers higher specificity because it is unaffected by prior BCG vaccination. Prior testing with QuantiFERON-TB Gold or QuantiFERON-TB Gold In-Tube does not affect the interpretation of QuantiFERON-TB Gold Plus results. A positive result indicates an immune response to TB antigens, regardless of previous testing or vaccination history.

Addressing Common Misconceptions about QuantiFERON TB Gold Plus

QuantiFERON-TB Gold Plus is not a standalone diagnostic tool for active TB disease. Instead, it aids in identifying individuals with latent TB infection, including low-risk health care workers. To ensure accurate interpretation, healthcare professionals should assess the test results alongside other clinical and laboratory findings, as well as consider the patient's overall health care needs. It's important to note that QuantiFERON-TB Gold Plus does not replace the need for contact tracing and other infection control measures, especially for health care workers. False-positive results may occur in individuals with non-tuberculous mycobacterial infections or autoimmune conditions. Therefore, it's crucial to perform the test following proper collection and processing protocols, with trained health care workers handling the specimen. By addressing these common misconceptions, we can enhance understanding and promote the appropriate utilization of QuantiFERON-TB Gold Plus as a valuable complementary tool in the fight against tuberculosis.

Practical Aspects of QuantiFERON TB Gold Plus

The practical aspects of QuantiFERON-TB Gold Plus make it a convenient and efficient option for TB testing. The blood collection process is easy and straightforward, requiring minimal handling and incubation time. Results can be obtained within 24 hours, providing a quick turnaround time for healthcare professionals. QuantiFERON-TB Gold Plus can be performed in any standard laboratory setting, making it accessible to healthcare facilities worldwide. It offers accurate and reliable results compared to other TB tests, ensuring confidence in its diagnostic capabilities. By incorporating NLP terms such as Mycobacterium tuberculosis, latent tuberculosis infection, and interferon gamma release assays, the test aligns well with international guidelines, including those set by the FDA and World Health Organization. With its practical advantages, such as the use of a green cap tube for TB1 samples, QuantiFERON-TB Gold Plus is an invaluable tool in the detection and monitoring of TB infections.

How Reliable is QuantiFERON TB Gold Plus in Monitoring TB Therapy?

QuantiFERON-TB Gold Plus is highly reliable in monitoring TB therapy. By quantifying the immune response to TB antigens, it can detect both active and latent TB infections. This test also helps monitor treatment responses and identify treatment failures. When used alongside clinical evaluation, it provides accurate quantitative results for easy tracking of progress.

Can QuantiFERON TB Gold Plus be Used for Children and Immunocompromised Individuals?

Quantiferon Gold Plus can be used for children and individuals with compromised immune systems. It provides accurate results without requiring a strong T-cell response, making it helpful in diagnosing TB in populations with weaker immune responses. Additionally, there is limited data about the performance of QFT-GIT in children under 17 years, especially in low-risk groups in regions where tuberculosis is endemic. This makes it a valuable tool for diagnosing TB in these populations. Additionally, it is less affected by previous BCG vaccinations compared to traditional tests and provides reliable results in immunosuppressed individuals.

Understanding Conversion and Reversion in QuantiFERON TB Gold Plus

Conversion and reversion are important concepts to understand when it comes to the QuantiFERON-TB Gold Plus test. Conversion refers to the indication of recent tuberculosis (TB) infection or reactivation. It shows that someone has been exposed to the bacterium Mycobacterium tuberculosis, and their immune system has responded by releasing interferon-gamma in response to specific antigens. Reversion, on the other hand, indicates a decrease in the immune response over time. It can be a result of waning immunity or successful treatment of the TB infection.

Monitoring conversions and reversions is crucial, as it helps healthcare professionals assess disease progression. By tracking these changes, they can identify individuals who may be at risk of developing active TB. Additionally, monitoring conversions and reversions assists in evaluating the effectiveness of TB prevention strategies, such as vaccination programs.

The QuantiFERON-TB Gold Plus test provides quantitative results, measured in international units (IU), making it easier to track progress over time. It is a reliable tool for assessing TB infection, both active and latent, and can be used in conjunction with clinical evaluation for a more accurate diagnosis.

To sum up, knowing about conversion and reversion in QuantiFERON-TB Gold Plus is important for figuring out how the disease is progressing, who is likely to have active TB, and how well TB prevention strategies are working. This test provides valuable insights into the immune response to TB and plays a significant role in the diagnosis and management of this infectious disease.

How Does QFT-Plus Compare with Traditional TB Blood Test Methods in Low-Risk Populations?

Compared to the traditional TST, QFT-Plus offers higher specificity and lower chances of false-positive results. It does not cross-react with BCG vaccination or most non-tuberculosis mycobacteria. In low-risk populations, QFT-Plus provides higher sensitivity, reduces the need for repeat testing, and offers faster turnaround time.

What are the Sources of Variability in QuantiFERON TB Gold Plus Test Results?

The QuantiFERON-TB Gold Plus test results can be changed by biological factors like age and immune status, as well as by pre-analytical factors like assay performance and lab procedures, and technical factors like assay performance and circadian rhythms. Standardization and quality control measures help minimize variability.

Debunking Myths about QuantiFERON-TB Gold Plus

There are several myths surrounding the QuantiFERON TB Gold Plus test that need to be addressed. Firstly, there is a misconception that the QFT-Plus is expensive compared to other TB tests. However, this is not true, as the cost of the QFT-Plus test is comparable to other diagnostic options available.

Another myth is that the QFT-Plus is not as accurate as the tuberculin skin test (TST). In reality, the QFT-Plus offers higher sensitivity and specificity in detecting active and latent tuberculosis infections compared to the TST.

Some people believe that the QFT-Plus cannot differentiate between active and latent TB. This is not true; the test measures the release of interferon-gamma in response to certain antigens of Mycobacterium tuberculosis. This lets it tell the difference between TB infections that are active and those that are not.

It is also mistakenly believed that specialized training is required for interpreting QFT-Plus results. However, the test provides clear positive and negative readings, making it easy to interpret without requiring specialized training.

Lastly, some think that the QFT-Plus is not suitable for high-burden TB settings. On the other hand, organizations like the World Health Organization have extensively validated and recommended the QFT-Plus for use in high-burden TB settings.

In conclusion, these myths about QuantiFERON-TB Gold Plus have been debunked with evidence and facts, highlighting the accuracy, effectiveness, and suitability of the test in various scenarios.

What Makes QuantiFERON-TB Gold Plus a Preferred Choice for TB Testing?

QuantiFERON-TB Gold Plus is less affected by the BCG vaccine and mycobacteria that do not cause tuberculosis because it has a higher specificity. It eliminates the risk of false-positive results due to the booster phenomenon. The test provides objective and quantitative results for easy interpretation while ensuring minimal patient discomfort compared to the TST. It can also be used on people who have had positive or unclear TST results in the past. This makes it a popular choice for TB testing because it can accurately find TB in people who have been vaccinated with BCG strains or who are infected with other mycobacteria that are not tuberculous.

How to Buy an Affordable Quantiferon Gold Test from DiscountedLabs.com

To purchase an affordable Quantiferon Gold Test from DiscountedLabs.com, start by browsing their website to explore the available options. Take into consideration your specific needs and select the test package that best suits you. Once you have made your selection, follow the instructions provided on the website to conveniently place your order online. After completing the order process, you will receive a lab requisition form, either via email or as a download from the website. This form is essential for your test procedure. Next, visit a participating lab, where a healthcare professional will collect a blood sample from you. Rest assured that the process is quick and efficient, and the use of our website allows for a seamless experience. Finally, you can expect to receive your test results in a timely manner, allowing you to gain valuable insights into your health status.


In conclusion, QuantiFERON-TB Gold Plus is a highly accurate and reliable test for detecting tuberculosis infection. Its advanced technology and methodology make it superior to traditional TB tests, such as the tuberculin skin test. With its high sensitivity and specificity, QuantiFERON-TB Gold Plus provides more accurate results, reducing the chances of false positives and false negatives. Additionally, it offers the advantage of detecting both active and latent TB infections. This test is particularly beneficial for individuals who have received the BCG vaccine or those with compromised immune systems. DiscountedLabs.com offers affordable QuantiFERON-TB Gold Plus tests, making it accessible to everyone. Take control of your health and get tested today.


[1] https://www.aafp.org/pubs/afp/issues/2021/0201/p177.html

[2] https://www.questdiagnostics.com/healthcare-professionals/clinical-education-center/faq/faq204

[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3571094/

[4] https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5202a2.htm


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