Transitional changes in T-cell responses to Mycobacterium tuberculosis-specific antigens during treatment.
BACKGROUND
Currently, there is no available test for monitoring the clinical effect of active tuberculosis (TB) disease treatment. Therefore, we studied the usefulness of two commercial IFN-gamma assays (QuantiFERON TB-2G (QFT-2G) and T-SPOT.TB tests) for monitoring clinical efficacy.


METHODS
The subjects were 40 patients with active TB disease. These two commercial IFN-gamma assays were carried out every three months during active TB disease treatment.


RESULTS
While the positive response rate of QFT-2G test significantly decreased from 83% at treatment initiation to 58% at treatment completion, that of T-SPOT.TB decreased from 90% at treatment initiation to 63% at treatment completion. Although there was a significant decrease in patients with TB infection showing positive responses for ESAT-6 only or CFP-10 only antigens on both IFN-gamma assays, there was no significant decrease in patients showing positive responses for both ESAT-6 and CFP-10 antigens on both IFN-gamma assays. On both QFT-2G test and T-SPOT.TB test, the mean values of the IFN-gamma levels in the pre- and post-treatment responses showed significantly decreased responses to CFP-10. On the other hand, smear conversion results of clinical specimens were obtained in all patients at treatment completion.


CONCLUSIONS
Antituberculous treatment induced a significant decrease in T-cell responses to separate ESAT-6 and CFP-10 antigens as measured by both IFN-gamma assays. Although IFN-gamma assays might be later than smear conversion results of clinical specimens, the quantitative responses especially to CFP-10 may be one of the useful monitoring markers of clinical efficacy for active TB disease treatment.
Division of Respiratory Diseases, Department of Medicine, Kawasaki Medical School, Kurashiki, Okayama, Japan. yoshihiro@med.kawasaki-m.ac.jp
Yoshihiro
Y
Kobashi
Keiji
K
Mouri
Shinichi
S
Yagi
Yasushi
Y
Obase
Naoyuki
N
Miyashita
Mikio
M
Oka
D000368:Aged; D000942:Antigens, Bacterial / Q000276:immunology; D000995:Antitubercular Agents / Q000276:immunology* / Q000627:therapeutic use*; D001426:Bacterial Proteins / Q000276:immunology; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000276:immunology; D013183:Sputum / Q000382:microbiology; D013601:T-Lymphocytes / Q000276:immunology*; D014376:Tuberculosis / Q000188:drug therapy* / Q000276:immunology*
D000942:Antigens, Bacterial; D000995:Antitubercular Agents; D001426:Bacterial Proteins; C117940:CFP-10 protein, Mycobacterium tuberculosis; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D007371:Interferon-gamma