Reduced total body naive and memory CD4⁺ T-cell numbers in HIV infection. (A) In healthy children (○), total body naive T-cell numbers increased over time, concomitant with an increase in CD27⁺ and CD27^– memory CD4⁺ T cells (B-C). In children infected with HIV (•) expansion of the naive (A) and memory (B-C) CD4⁺ T-cell pools was significantly reduced. See Table 2 for nonparametric Spearman correlation coefficients of all parameters with age.