Detection of active tuberculosis infection by T cell responses to early-secreted antigenic target 6-kDa protein and culture filtrate protein 10

J Infect Dis. 2000 May;181(5):1850-4. doi: 10.1086/315448. Epub 2000 May 15.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Antibody Formation
  • Antigens, Bacterial / immunology*
  • BCG Vaccine*
  • Bacterial Proteins / immunology*
  • Child
  • Humans
  • Lymphocyte Activation
  • Middle Aged
  • ROC Curve
  • T-Lymphocytes / immunology*
  • Tuberculin Test*
  • Tuberculosis / immunology*
  • Tuberculosis / prevention & control


  • Antigens, Bacterial
  • BCG Vaccine
  • Bacterial Proteins
  • CFP-10 protein, Mycobacterium tuberculosis
  • ESAT-6 protein, Mycobacterium tuberculosis