What is CD8 T-cell technology?
CD8 T cells seek out and destroy infected cells as part of the cell-mediated immune response to infection. Together with CD4 T cells, CD8 T cells are critical for identifying and eliminating infected cells – particularly for intracellular infections like tuberculosis (TB). CD8 T-cell technology enables detection of CD8 responses, for a more complete picture of the immune response to TB.
What is the role of CD8 T cells in tuberculosis?
CD8 T cells contribute to TB immunity by producing interferon-gamma (IFN-γ) and other factors that suppress M. tuberculosis, kill infected cells and lyse intracellular bacteria. Research indicates that CD8 T-cell responses are more common in active TB than during latent infection, are linked to recent TB exposure and are detectable even in HIV-positive patients and children (1–6).
How does QuantiFERON-TB Gold Plus use CD8 T-cell technology?
Advantages of CD8 technology in TB diagnostics
A large meta-analysis based on 17 research studies and 4050 subjects has illustrated the unique clinical value of the CD8 signal detected by the QFT-Plus TB2 antigen tube (7). Higher test values were consistently found in the TB2 tube compared to the TB1 tube across all patients, affirming the important role of CD8 T cells for a broad immune assessment of TB infection.
The study also showed that CD8 signal from the TB2 tube was significantly higher among those with active TB disease compared to those with inactive (latent) TB infection. The authors identified potential benefits of the TB2 tube for CD8 signal detection in high-risk populations, such as immunocompromised patients and those with CD4 T-cell deficiency.
Who should get tested with a TB blood test?
Anyone can become infected with TB, but certain populations are at higher risk of infection and progression to TB disease. These include people with weakened immune systems, such as those with HIV, diabetes or young children, as well as individuals in high-prevalence settings or in close contact with people who have active TB.
Advance your TB testing with QuantiFERON
References
- Day CL, Abrahams DA, Lerumo L, et al. Functional capacity of Mycobacterium tuberculosis-specific T cell responses in humans is associated with mycobacterial load. J Immunol. 2011;187(5):2222.
- Rozot V, Patrizia A, Vigano S, et al. Mycobacterium tuberculosis-specific CD8+ T cells are functionally and phenotypically different between latent infection and active disease. Eur J Immunol. 2013;43(6):1568.
- Nikolova M, Markova R, Slavchev G, et al. Antigen-specific CD4- and CD8-positive signatures in different phases of Mycobacterium tuberculosis infection. Diagn Microbiol Infect Dis. 2013;75(3):277.
- Chicchio T, Sauzullo I, Mengoni F, et al. Polyfunctional T-cells and effector memory phenotype are associated with active TB in HIV-infected patients. J Infect. 2014;69(6):533.
- Ongaya A, Siawaya JFD, Kimuda SG, et al. Mycobacterium tuberculosis-specific CD8+ T cell recall in convalescing TB subjects with HIV co-infection. Tuberculosis. 2013;93(Suppl):S60.
- Lanicioni C, Petruccioli E, Petrone L, et al. CD8+ T cells provide an immunologic signature of tuberculosis in young children. Am J Respir Crit Care Med. 2012;185(2):206.
- Darmawan G, Takasaki J, Harada N. Comparison of interferon-gamma production between TB1 and TB2 tubes of QuantiFERON-TB Gold Plus: a meta-analysis. Clin Chem Lab Med. 2023;10.1515/cclm-2023-0293.
- Andersen P., Doherty TM, Pai M and Weldingh K The prognosis of latent tuberculosis: can disease be predicted. Trends Mol Med. 2007;13(5):175–82.