Detection of active tuberculosis infection by T cell responses to early-secreted antigenic target 6-kDa protein and culture filtrate protein 10.
The purified protein derivative (PPD) skin test has no predictive value for tuberculosis (TB) in Mycobacterium bovis bacillus Calmette-Guérin (BCG)-vaccinated individuals because of cross-reactive responses to nonspecific constituents of PPD. T cell responses to early-secreted antigenic target 6-kDa protein (ESAT-6) and the newly identified culture filtrate protein 10 (CFP-10), 2 proteins specifically expressed by M. tuberculosis (MTB) but not by BCG strains, were evaluated. Most TB patients responded to ESAT-6 (92%) or CFP-10 (89%). A minority of BCG-vaccinated individuals responded to both ESAT-6 and CFP-10, their history being consistent with latent infection with MTB in the presence of protective immunity. No responses were found in PPD-negative controls. The sensitivity and specificity of the assay were 84% and 100%, respectively, at a cutoff of 300 pg of interferon-gamma/mL. These data indicate that ESAT-6 and CFP-10 are promising antigens for highly specific immunodiagnosis of TB, even in BCG-vaccinated individuals.
Arend
S M
SM
Dept. of Infectious Diseases, C5P, Leiden University Medical Center, 2300 RC Leiden, The Netherlands. smarend@lumc.nl.
Andersen
P
P
van Meijgaarden
K E
KE
Skjot
R L
RL
Subronto
Y W
YW
van Dissel
J T
JT
Ottenhoff
T H
TH
D000293:Adolescent; D000328:Adult; D000368:Aged; D000917:Antibody Formation; D000942:Antigens, Bacterial / Q000276:immunology*; D001500:BCG Vaccine; D001426:Bacterial Proteins / Q000276:immunology*; D002648:Child; D006801:Humans; D008213:Lymphocyte Activation; D008875:Middle Aged; D012372:ROC Curve; D013601:T-Lymphocytes / Q000276:immunology*; D014374:Tuberculin Test; D014376:Tuberculosis / Q000276:immunology* / Q000517:prevention & control
D000942:Antigens, Bacterial; D001500:BCG Vaccine; D001426:Bacterial Proteins; C117940:CFP-10 protein, Mycobacterium tuberculosis; C093276:ESAT-6 protein, Mycobacterium tuberculosis