Naive CD4 T cells and TREC contents. (A) Comparative analysis between the percentage of CD45RA⁺CD4⁺ T cells in HIV-negative subjects (□) and in 42 randomly selected HIV-1-infected subjects (▦) at early and intermediate stages of disease. (B) Correlation between the percentage of CD45RA⁺CD4⁺ T cells and TREC contents within the CD4 T-cell population in HIV-1-infected subjects. Data are expressed as mean ± SE.