Figure 1: Enumeration of antigen-specific CD4+IFN-γ +TNF-α + T cells in HHC and TB patients. Scatter plots show antigen-specific CD4+IFN-γ +TNF-α + T cells in HHC and TB patients. The frequency of antigen-specific ((a) PPD, (b) ESAT-6, and (c) CFP-10) CD4+IFN-γ +TNF-α + T cells was significantly higher in TB patients compared to HHC for all three antigens. The difference between HHC and TB was calculated by Mann-Whitney test. TB: tuberculosis patients; HHCs: healthy household contacts.