Evaluation of the diagnostic utility of a whole-blood interferon-gamma assay for determining the risk of exposure to Mycobacterium tuberculosis in Bacille Calmette-Guerin (BCG)-vaccinated individuals.
We evaluated the utility of the "QuantiFERON-TB Gold In-Tube" (QuantiFERON) test that uses tuberculosis (TB)-specific antigens for the diagnosis of latent infection in such individuals. We also examined the correlation between the interferon (IFN)-gamma response to these antigens and the exposure risk to TB by evaluating antigen-specific IFN-gamma release in comparison with IFN-gamma release in response to purified protein derivative (PPD) in 3 groups: medical students, nurses in a TB hospital, and TB patients. All nurses and TB patients responded to PPD, whereas 52% (P < 0.0001) and 79.2% (P = 0.04) responded to QuantiFERON, respectively. In the medical students, only 10.4% responded to QuantiFERON, whereas 85.2% were positive to PPD (P < 0.0001). There was also a significant correlation between the levels of IFN-gamma production and the duration of employment in the group of nurses at the TB hospital, suggesting ongoing exposure in this high-risk group. Thus, these results demonstrate that Mycobacterium tuberculosis-specific IFN-gamma release assay accurately discriminates low- and high-risk healthy subjects and might therefore be a useful diagnostic tool for the diagnosis of latent infection in Bacille Calmette-Guerin (BCG)-vaccinated individuals.
Eum
Seok-Yong
SY
International Tuberculosis Research Center, Division of Immunopathology and Cell Immunology, Masan, Republic of Korea. syeumkr@gmail.com
Lee
Ye-Jin
YJ
Kwak
Hyun-Kyung
HK
Min
Jin-Hong
JH
Hwang
Soo-Hee
SH
Via
Laura E
LE
Barry
Clifton E
CE
Cho
Sang-Nae
SN
D000328:Adult; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009163:Mycobacterium bovis / Q000276:immunology*; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D009726:Nurses; D013337:Students, Medical; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis* / Q000517:prevention & control
D007371:Interferon-gamma