Antigen-Specific IFN-γ Responses Correlate with the Activity of M. tuberculosis Infection but Are Not Associated with the Severity of Tuberculosis Disease

Figure 3

The performance of QFT in HD, TBC, and patients with different TB activity. (a) Percent of positive QFT results in groups of study participants having different risk of Mtb infection. (b) Percent of positive QFT results in TBS having different activity of TB disease. (c–f) The levels of antigen-driven IFN-γ secretion in groups of participants with different risk (c, d) and activity (e, f) of TB infection. (g, h) The levels of antigen-driven IFN-γ secretion in HD, TBC, and TBP with positive QFT results. IFN-γ concentrations greater than 10 IU/mL were assigned a value of 10 IU/mL. HD, healthy donors; TBC, TB contacts; TBP, TB patients; TBS-RL, TB suspects having residual TB lesions in the lungs; TBS-TB⁺-low activity, TB suspects diagnosed for pulmonary TB and having radiological signs of low TB activity; TBS-TB⁺ high activity, TB suspects diagnosed for pulmonary TB and having radiological signs of high TB activity. Shown are the differences determined in Mann-Whitney test (; ; ). Solid lines indicate differences that were also significant in Kruskal-Wallis test with Dunn’s posttest. Dotted lines, differences significant in Mann-Whitney and insignificant in Kruskal-Wallis test with Dunn’s posttest.