Table 2

TST+ subjects without a past MTB exposure: trends of RD1 test during follow up in the responders*

Group of subjects analysed
Number of subjects
N (%)
Time 1
0 months
Time 2
1–2 months
Time 3
6 months
Time 2 vs time 1
Time 3 vs time 1



IFN-gamma (IU/ml)



No INH
6 (100)





PHA
6 (100)
9.9 ± 4.3
8.6 ± 4.1
12.1 ± 6.5
Ns
Ns
PPD
6 (100)
27.4 ± 3.1
21.4 ± 4.9
23.5 ± 3.8
Ns
Ns
QTF-G
6 (100)
21.1 ± 5.2
19.5 ± 7.2
20.2 ± 6.1
Ns
Ns
RD1 proteins
6 (100)
16.1 ± 4.5
16.3 ± 7.2
7.3 ± 2.2
Ns
Ns
RD1 peptides
6 (100)
7.5 ± 3.3
7.0 ± 4.7
5.7 ± 4
Ns
Ns







INH therapy
24 (100)





PHA
24 (100)
14.7 ± 2.7
16.8 ± 3
14.8 ± 2.8
Ns
Ns
PPD
24 (100)
17.6 ± 2.8
15.6 ± 2.7
14.1 ± 2.5
Ns
Ns
QTF-G
19 (79)
17.5 ± 2.7
11.6 ± 2.5
5.2 ± 1.3
p = 0.03
p = 0.0001
RD1 proteins
18 (75)
12.5 ± 2.6
5.4 ± 1.4
2.6 ± 0.9
p = 0.001
p = 0.0002
RD1 peptides
15 (63)
9.2 ± 1.7
3.4 ± 0.9
0.9 ± 0.1
p = 0.005
p = 0.0005

*Responders are defined as those responding to the tests at baseline.

T1: time 1 (baseline); T2. time 2 (after 1–2 months INH therapy), T3: time 3 (after 6 months, at therapy completion). IFN: interferon; PHA: Phytohemagglutinin; PPD: purified protein derivative; RD: region of difference; QTF-G: QuantiFERON TB Gold; IFN: interferon; IU: international units. INH: isoniazid; ns: not statistically significant.

Goletti et al. Respiratory Research 2007 8:5   doi:10.1186/1465-9921-8-5