Interferon gamma production - Quantiferon® TB Gold Plus

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Eurofins Biomnis code

QANR

Synonyms
  • IGRA
  • Infection tuberculeuse latente
  • Interferon gamma production blood test
  • Interferon Gamma Release Assays
  • Quantiferon® TB Gold Plus
  • Quantiferon test
Specialty

Infectious

Clinical significance

Latent tuberculosis infection (LTBI) is defined as a persistent immune response to stimulation by Mycobacterium tuberculosis complex antigens, without clinical signs of active tuberculosis. The risk of reactivation into active tuberculosis (TB) is highest in the first 2 years following primary infection and decreases significantly after 5 years. This reactivation occurs in the majority of cases in children and in situations that induce immunosuppression. The QuantiFERON® TB test is an in vitro blood test of the cell-mediated immune response. It measures the release of interferon-gamma (IFN-gamma) by T cells following stimulation by antigens specific to the M. tuberculosis complex, in particular the ESAT-6 and CFP-10 antigens, which are not found in BCG vaccine strains. There is therefore no analytical interference in vaccinated patients.The main indication for the QuantiFERON® test is the diagnosis of LTBI due to its high negative predictive value (NPV) in countries with low incidence of tuberculosis. It therefore allows for the diagnosis of exclusion of LTBI.The QuantiFERON® test is not: - Intended for the diagnosis of active TB due to its low sensitivity during certain phases of the disease. This test therefore cannot rule out active TB in the event of a negative result. - Recommended for monitoring treatment of ITL or TM (only 1/3 of tests will become negative in the months following successful treatment).Pre-analytical instructions for sampling and pre-treatment of tubes must be strictly followed to avoid false positive and false negative results. Please note that the interpretation of the result is qualitative. If a tuberculin skin test (TST) has been performed, it is necessary to wait at least 8 weeks before taking a sample from the patient for a QuantiFERON® test.

Preanalytics
  • A tube specifically for this analysis : No
Further information

Sampling to be carried out using the Quantiferon kit, to be ordered 3 days before the sample. Scrupulous compliance with the pre-analytical phase is required to ensure the quality of the result, in particular: - stir the tubes well before incubating 16 to24h at 36-38ºC - centrifuge before sending at +4ºC. There are no recommendations on centrifugation but the gel needs to be positioned between the cap and the plasma.
[To be translated]
- Do not aliquot; transfer the primary tube.

Specific equipment available
  • K4: Quantiferon sampling kit
Documents to download
Methodology

Enzyme-immunoassay

Turnaround time

3 days

Testing Laboratory

Biomnis Lyon

Contact(s)
Customer Care