The mean quantity of IFN-γ produced in response to the <i>M.tb</i>-specific antigens used in IGRA.

<p>A.B. The cut-off value for a positive response was set at 0.163 IU/ml by receiver operator characteristic (ROC) curve analysis. C. Each dot represents individual response of one participant in the study and horizontal lines represent the mean values. The geometric mean ± SD for culture-positive TB was 2.78±3.50 IU/ml (n = 32), for culture-negative TB 4.24±3.86 IU/ml (n = 22) and for NMLD 3.89±5.19 IU/ml (n = 11).