Table 2.
The associations (1) between the interferon-gamma level of QuantiFERON-TB Gold In-tube (QFT-GIT) at baseline and at 1st follow-up with the QFT-GIT and QuantiFERON-TB Gold Plus (QFT-Plus) and (2) between the two tests at 1st follow-up.
| mean ± SD | p | Spearman coefficient | |
|---|---|---|---|
| (1) QFT-GIT0* | 2.31 ± 2.40 | ||
| versus QFT-GIT1* | 1.49 ± 1.97 | < 0.001 | 0.520 |
| versus T1 of QFT-Plus1* | 1.30 ± 1.80 | < 0.001 | 0.611 |
| versus T2 of QFT-Plus1* | 1.36 ± 1.92 | < 0.001 | 0.611 |
| versus T2–T1 of QFT-Plus1* | 0.064 ± 0.513 | 0.477 | 0.085 |
| (2) QFT-GIT1* | 1.49 ± 1.97 | ||
| versus T1 of QFT-Plus1* | 1.30 ± 1.80 | < 0.001 | 0.879 |
| versus T2 of QFT-Plus1* | 1.36 ± 1.92 | < 0.001 | 0.895 |
| versus T2–T11 of QFT-Plus1* | 0.064 ± 0.513 | 0.206 | 0.150 |
QFT-GIT response: the interferon-gamma level of the TB antigen tube minus the negative control.
T1 or T2 response: the interferon-gamma level of the TB1 or TB2 tube, respectively, minus the negative control of the QFT-Plus test.
All QFT responses are represented as IU/ml.
*0: baseline test; 1: 1st follow-up, around 6 months later.