Figure 4

A-B. A higher ratio of the response to RD1 antigens in relation to CD4 ⁺ T-cell count is associated with active TB in HIV ⁺ subjects. ELISPOT counts per million PBMC for each antigen were divided by the corresponding total CD4⁺ T-cell count per mm³ and were plotted against CD4⁺ T-cell counts. Shaded symbols indicate patients with TB and unshaded symbols indicate individuals without TB. A) For the response to selected RD1 peptides, a ratio in the TB group (shaded symbols) higher than 0.21 predicted active TB with 100% sensitivity and 80% specificity). B) For the response to RD1 proteins, a ratio in the TB group (shaded symbols) higher than 0.22 predicted active TB with 89% sensitivity and 70% specificity.