Table 4.
Comparison of TB antigen-specific IFN-γ secreting T cell levels in response to TB antigens in the QFT-Plus and TB-Feron assays measured by flow cytometry intracellular cytokine analysis.
| No. of Cases | % of TB Antigen-Specific IFN- Secreting T Cells |
p-Value † (TB1 vs. TB2) |
p-Value † (TB1 vs. TBF) |
p-Value † (TB2 vs. TBF) |
|||
|---|---|---|---|---|---|---|---|
| QFT-Plus TB1 |
QFT-Plus TB2 |
TB-Feron | |||||
| ATB CD4+ | 38 | 0.18 (0.11–0.29) | 0.10 (0.04–0.21) | 0.07 (0.02–0.23) | 0.0308 | 0.2004 | 0.8777 |
| ATB CD8+ | 0.10 (0.00–0.21) | 0.04 (0.00–0.15) | 0.22 (0.03–0.58) | 0.3414 | 0.1597 | 0.0249 | |
| P-LTBI CD4+ | 10 | 0.12 (0.03–0.22) | 0.11 (0.03–0.36) | 0.22 (0.07–0.74) | 0.2031 | 0.0645 | 0.0273 |
| P-LTBI CD8+ | 0.00 (0.00–0.02) | 0.00 (0.00–0.05) | 0.34 (0.00–1.12) | 0.6250 | 0.0469 | 0.0156 | |
| H-LTBI CD4+ | 8 | 0.06 (0.00–0.12) | 0.06 (0.01–0.12) | 0.02 (0.00–0.13) | 0.8125 | 1.0000 | 0.6875 |
| H-LTBI CD8+ | 0.00 (0.00–0.03) | 0.00 (0.00–0.08) | 0.21 (0.00–0.41) | 0.6250 | 0.0625 | 0.0625 | |
| HC CD4+ | 12 | 0.02 (0.00–0.06) | 0.02 (0.00–0.04) | 0.00 (0.00–0.04) | 0.7058 | 0.6166 | 0.5195 |
| HC CD8+ | 0.00 (0.00–0.01) | 0.00 (0.00–0.08) | 0.19 (0.06–0.56) | 0.1594 | 0.0304 | 0.0463 | |
Percentage of IFN-γ released by CD4+ or CD8+ T lymphocytes, median (95% CI). † Categories in each group were compared using the Wilcoxon signed-rank test. Abbreviation: TB, tuberculosis; TB1 or 2, QFT-Plus TB antigen tube 1 or 2; TBF, Standard E TB-Feron; IFN-γ, interferon-gamma.