Fig. 2

Correlation of T cell numbers with antigen-induced induration. CD4 and CD8 T cell counts were measured for TB patients that were HIV positive (n = 38) and are plotted against the skin induration measured 24 h after they were intradermally inoculated with either 5 TU of Tubersol PPD Tuberculin or the bioequivalent 1 µg of DPPD. Each dot represents an individual data point, while the solid line represents the correlation of results and the black dotted lines represent the 95% confidence intervals. The r² value is indicated in the text insert. In B, per cent of each group falling within the indicated induration range is plotted