Recovery of lymphopoiesis with ART. (A) Absolute counts of CD34⁺ CD45^low Lin⁻ cells in HIV-1–infected patients with low CD4⁺ T-cell nadir before treatment (< 200 cells/μL) and treated for > 3 years with ART, grouped according to CD4⁺ T-cell counts: > 500 (Hx; n = 13), between 200 and 500 (Ix; n = 28), or < 200 (Lx; n = 13) cells/μL. For comparison, counts in middle-aged control adults (M; n = 27), treatment-naive HIV-1–infected patients with CD4⁺ T-cell count < 200 cells/μL (L;, n = 23), and treated HIV-1–infected patients with high CD4⁺ T-cell nadir and counts (> 500 cells/μL) (Hxh; n = 21) are also shown. (B) CD4-to-CD8 ratios and (C) absolute naive CD4⁺ or CD8⁺ T-, B-, and NK-cell counts in ART-treated HIV-1–infected patients or comparative donor groups. Bars indicate the median. The Kruskal-Wallis test was used for group comparison. *P < .05, **P < .01, and ***P < .001.