Table 3.

Sensitivity and specificity of PPD and the combination of ESAT-6 and CFP-10 in TB patients and healthy controlsa

Cutoff value for IFN-γ release pg/mlAntigenNo. of responders/ total no.Sensitivity (%)aSpecificity (%)b
TB patientsHealthy controlsc
>300 PPD10/1114/14910
ESAT-6/CFP108/114/147371
>1,000PPD9/1113/14827
ESAT-6/CFP108/111/147393
  • a Percentage of positive responders in the TB-infected group.

  • b Percentage of nonresponders to the antigen in the noninfected group.

  • c BCG-vaccinated and nonvaccinated individuals.