Comparison of T-cell interferon-gamma release assays for Mycobacterium tuberculosis-specific antigens in patients with active and latent tuberculosis.
Through the use of QuantiFERON-TB Gold, a commercial IFN-gamma assay, we compared differences in quantitative T-cell responses to Mycobacterium tuberculosis (MTB)-specific antigens [QuantiFERON TB-2G (QFT-2G)] between patients with active tuberculosis (TB) disease and those with latent TB infection (LTBI). The patient group consisted of 180 patients with active TB disease (culture-positive for MTB) and 50 screening contacts with LTBI-positive response to the QFT-2G test. We prospectively performed a tuberculin skin test (TST) and a QFT-2G test for all subjects. The median IFN-gamma levels upon the application of both antigens, ESAT-6 and CFP-10, were significantly higher in patients with active TB disease than in those with LTBI. A combined positive response to both antigens occurred at a higher rate in patients with active TB disease than in those with LTBI. There were no significant relationships between the quantitative responses of IFN-gamma to both antigens and the maximum induration on TST in both patient groups. We demonstrated significant differences in the quantitative responses of IFN-gamma to MTB between patients with active TB disease and those with LTBI in this study. However, there was an overlap in the IFN-gamma levels between active TB disease and LTBI groups. Therefore, it would be difficult to use the QFT-2G test to completely discriminate active TB disease from LTBI.
Kobashi
Yoshihiro
Y
Division of Respiratory Diseases, Department of Medicine, Kawasaki Medical School, 577 Matsushima, Kurashiki, Japan. yoshihiro@med.kawasaki-m.ac.jp
Shimizu
Hiroki
H
Ohue
Yoshihiro
Y
Mouri
Keiji
K
Obase
Yasushi
Y
Miyashita
Naoyuki
N
Oka
Mikio
M
D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007159:Immunologic Tests; D007371:Interferon-gamma / Q000032:analysis / Q000276:immunology*; D055985:Latent Tuberculosis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification*; D013601:T-Lymphocytes / Q000276:immunology*; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*
D000942:Antigens, Bacterial; C072681:Mycobacterium tuberculosis antigens; D007371:Interferon-gamma