CD4⁺ T cells that were dull double-positive for CD45RA⁺/CD45RO⁺ were increased in IL-2–treated patients and expressed high levels of CD25.

For the results shown in panel A, gating was done on CD3⁺/CD4⁺ cells. A representative example from each group is shown. In panel B, the histograms of CD25 expression on the different CD4⁺ T cell subsets are shown for an IL-2–treated patient (R1, CD45RA⁺/RO⁻ cells; R2, dull double-positive CD45RA⁺/CD45RO⁺ cells, and R3, CD45RO⁺/RA⁻). In panel C, the number of dull RA⁺/RO⁺ CD4⁺ cells is shown to be associated with the total CD4⁺ T-cell count in both the HAART group (circles) and the IL-2+HAART group (squares). Spearman rank correlation coefficients and P values are shown.