ROC curve analysis for TB antigens specific IP-10.

<p>The cut-off value for TB antigens specific IP-10 levels was determined by using QFT-IT and TST negative healthy controls as uninfected and culture confirmed TB patients as diseases subjects. The area under curve was 0.946 (95% CI: 0.905–0.987). TB- tuberculosis; IP-10-Interferon gamma inducible protein-10; QFT-IT – QuantiFERON-TB Gold in-tube; TST – Tuberculin Skin test; CI-Confidence interval.</p

The levels of IFN-γ in unstimulated, TB antigens stimulated and mitogen stimulated samples of healthy controls (a) and PTB patients (b).

<p>The levels of <b>IFN-γ</b> in TB antigen stimulated and mitogen stimulated samples were significantly higher that unstimulated samples. Box and Whisker plots show range, inter-quartile range and median. Nil – unstimulated; TB ag – TB antigens stimulated; mitogen- mitogen stimulated samples. *significant difference p<0.05 by Kruskal- Wallis test.</p

Analysis of combination of tests.

<p>10 mm cut-off point was used for TST.</p><p>Specificity was calculated as number of subjects negative for both the two tests among the total number of healthy subjects, after excluding the indeterminate results.</p><p>Sensitivity was calculated as number of subjects positive for either test among PTB patients, after excluding the indeterminate results.</p><p>QFT-IT - QuantiFERON-TB Gold.</p><p>IP-10 - Interferon gamma inducible protein-10.</p><p>TST - Tuberculin skin test.</p><p>CI - Confidence interval.</p><p>% Sen - Percentage of sensitivity.</p><p>% spe - Percentage of specificity.</p

Positivity of QFT-IT, IP-10 and TST in healthy adult subjects.

<p>10 mm cut-off point was used for TST.</p><p>QFT-IT - QuantiFERON-TB Gold.</p><p>IP-10 - Interferon gamma inducible protein-10.</p><p>TST - Tuberculin skin test.</p><p>N - Number of subjects.</p><p>Pos - Positive.</p><p>Neg - Negative.</p><p>Indt - Indeterminate.</p><p>% Spec - Percentage of specificity, calculated after excluding indeterminate results.</p

Analysis of variables associated with positive QFT-G test results.

<p>BMI – Body mass index.</p><p>N – Number of patients tested.</p

The level of total lymphocyte and T cell counts in QFT-G positive, negative and indeterminate subjects.

<p>The decline of total lymphocytes (a) or CD3 count (b) or CD4 count (c) or CD8 count (d) was associated with QFT-G indeterminate only but not with QFT-G negative. Box and Whisker plots show range, inter-quartile range and median. QFT-G – Quantiferon TB Gold (in-tube), * significant difference p<0.05, **significant difference p<0.01 by Mann-Whitney U test.</p

Analysis of variance associated with TST positive results.

<p>BMI – Body mass index.</p><p>N – Number of patients tested.</p

Agreement between TST and QFT-G test results.

<p>Among the 105 subjects tested, 72 were negative for TST. Of the 72 TST negative, 50% were positive for QFT-G. None of the TST positive was negative or indeterminate for QFT-G. TST-Tuberculin Skin Test, QFT-G-Quantiferon TB Gold in-tube, Pos - Positive, Neg - Negative, Indt – Indeterminate.</p

The level of IFN-γ secretion in response to PHA in QFT-G indeterminate subjects.

<p>The level of IFN-γ secretion in response to PHA in QFT-G indeterminate subjects.</p

The level of total lymphocyte and T cell count in TST Positive and negative subjects.

<p>The level of total lymphocytes (a), CD3 count (b), CD4 count (c) were significantly low in TST negatives than TST positives whereas CD8 count (d) was not significantly different. Box and Whisker plots show range, inter-quartile range and median. TST – Tuberculin skin test, * significant difference p<0.05 by Mann-Whitney U test.</p