Quantiferone | Tuberculosis test

Quantifferon The test is a blood test used to diagnose both latent and active forms of tuberculosis.

The test measures the intensity of the cellular immune response to antigens similar to ESAT-6 and CFP-10 proteins (ESAT-6 and CFP-10 are produced by mycobacteria). People infected with mycobacteria usually have T lymphocytes in their blood that recognize these antigens (ESAT-6 and CFP-10). The identification process involves the production and release of cytokines, particularly γ-interferon, which can be detected and quantified by enzyme-linked immunosorbent assay (ELISA).

Unlike the tuberculin test, the results of the quantiferone test are not affected by BCG vaccination and are less affected by non-tuberculous mycobacterial infections. In addition, no hypersensitivity side effects were observed during the quantiferous test. Its results are much more objective - without errors in reading and interpretation.

General Information

Tuberculosis Is a contagious respiratory infectious disease caused by mycobacteria, which are of three types: Mycobacterium tuberculosis (Most common), m bovis და M. africanum.

Tuberculosis infection includes as Active, also Latent forms. Latent tuberculosis develops when it causes an infection M. tuberculosis And the body's immune system controls and limits the infection but is unable to eliminate it.

It is estimated that approximately 10% of people with latent tuberculosis go into active form during their lifetime. Causes of latent infection reactivation include HIV infection, treatment with TNFα antagonists, and more. For this reason, diagnosing latent tuberculosis is an important step in preventing infection reactivation, especially in high-risk individuals.

Treatment of latent tuberculosis can significantly reduce the risk of progression to the active form.

When to take a quantiferous test?

Quantifferon test is performed in the following cases:

• Suspicion of active or latent form of tuberculosis;
• Contact with a patient with an active form of tuberculosis;
• Monitoring disease progression, activity, and treatment effectiveness;
• Screening of high-risk individuals: staff of medical institutions, persons living in unhygienic environments, etc.

The study is recommended on the advice of a doctor in the presence of symptoms such as: Weakness and fatigue, low-grade fever, night sweats, weight loss, prolonged cough with sputum of various characteristics.

Note: Quantifferon replaces the tuberculin test and therefore both tests should not be used at the same time.

How to prepare for the test?

Immunosuppressive therapy should be discontinued at least 14 days prior to testing.

No special preparation is required for the test.

Research material

Venous blood

Possible interpretation of the results

Negative result:

Under the given conditions can be excluded Mycobacterium tuberculosisInfection with. However, in patients with chronic HIV infection or other severe immunodeficiency conditions (treatment with immunosuppressive drugs, lymphoma, some tumors, diabetes, silicosis, chronic renal failure), current immune status should be considered.

A negative result in people who have recently had contact with a TB patient should be confirmed by a new test 6-8 weeks after contact.

Positive result:

A positive result indicates M. tuberculosisOn infection. In most cases, this test makes it impossible to differentiate between latent and active infection.

In case of clinical suspicion of active tuberculosis, it is possible to use all methods of microbiological diagnostics (microscopy, bacteriology) and molecular biology.

Uncertain result:

If the sample is collected and transported under appropriate conditions and we have an uncertain result, it is likely to indicate severe immunosuppression caused by AIDS, other serious illnesses, or immunosuppressive medications (high-dose corticosteroids, TNFα antagonists, medications used during transplantation).

The prognostic value of the test depends on the prevalence of tuberculosis in the study population. The test result should be interpreted in the patient's clinical and epidemiological context. It is rarely possible to obtain a false positive result in patients infected with non-tuberculous mycobacteria (M. kansasii, M. szulgai and M. Marinum).

Resources

https://www.synevo.bg/quantiferon-tuberkuloza/

https://www.synevo.ro/shop/quantiferon-tbc-test/