Abstract |
The tuberculin skin test (TST) and interferon gamma (IFN-γ) release assays (IGRAs) are used as adjunctive tests for the evaluation of suspected cases of active tuberculosis (TB). However, a positive test does not differentiate latent from active TB. We investigated whether flow cytometric measurement of novel combinations of intracellular cytokines and surface makers on CD4 T cells could differentiate between active and latent TB after stimulation with Mycobacterium tuberculosis-specific proteins. Blood samples from 60 patients referred to the Singapore Tuberculosis Control Unit for evaluation for active TB or as TB contacts were stimulated with purified protein derivative ( PPD), ESAT-6 and CFP-10, or heparin-binding hemagglutinin (HBHA). The CD4 T cell cytokine response (IFN-γ, interleukin-2 [IL-2], interleukin-17A [IL-17A], interleukin-22 [IL-22], granulocyte-macrophage colony-stimulating factor [ GM-CSF], and tumor necrosis factor alpha [TNF-α]) and surface marker expression (CD27, CXCR3, and CD154) were then measured. We found that the proportion of PPD-specific CD4 T cells, defined as CD154(+) TNF-α(+) cells that were negative for CD27 and positive for GM-CSF, gave the strongest discrimination between subjects with latent and those with active TB (area under the receiver operator characteristic [ROC] curve of 0.9277; P < 0.0001). Also, the proportions and absolute numbers of HBHA-specific CD4 T cells were significantly higher in those with latent TB infection, particularly CD154(+) TNF-α(+) IFN-γ(+) IL-2(+) and CD154(+) TNF-α(+) CXCR3(+). Finally, we found that the ratio of ESAT-6- and CFP-10-responding to HBHA-responding CD4 T cells was significantly different between the two study populations. In conclusion, we found novel markers of M. tuberculosis-specific CD4 cells which differentiate between active and latent TB.
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Authors | Paul Hutchinson, Timothy M S Barkham, Wenying Tang, David M Kemeny, Cynthia Bin-Eng Chee, Yee T Wang |
Journal | Clinical and vaccine immunology : CVI
(Clin Vaccine Immunol)
Vol. 22
Issue 2
Pg. 200-12
(Feb 2015)
ISSN: 1556-679X [Electronic] United States |
PMID | 25520147
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | Copyright © 2015, American Society for Microbiology. All Rights Reserved. |
Chemical References |
- Antigens, Bacterial
- Antigens, CD
- Bacterial Proteins
- CFP-10 protein, Mycobacterium tuberculosis
- Cytokines
- ESAT-6 protein, Mycobacterium tuberculosis
- Lectins
- Tuberculin
- heparin-binding hemagglutinin
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Topics |
- Adult
- Aged
- Antigens, Bacterial
(immunology)
- Antigens, CD
(analysis)
- Bacterial Proteins
(immunology)
- CD4-Positive T-Lymphocytes
(immunology)
- Cytokines
(metabolism)
- Diagnosis, Differential
- Female
- Flow Cytometry
(methods)
- Humans
- Lectins
(immunology)
- Male
- Middle Aged
- Mycobacterium tuberculosis
(immunology)
- ROC Curve
- Singapore
- Tuberculin
(immunology)
- Tuberculosis
(diagnosis, immunology)
- Young Adult
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