Fig. 3

Frequency of CD45RO-expressing memory CD4⁺ T cells, but not CD57⁺ CD4⁺ T cells, is associated with CD4⁺ T cell decline. PBMC samples were analyzed by flow cytometry by first gating on the total mononuclear cells and then on the CD3⁺ T cells. The frequency of (a) CD4⁺ CD45RO⁺ T cells was then determined. The correlations between total peripheral blood CD4⁺ T cell counts and (b) T cells CD4⁺ CD45RO⁺ T cells, (c) CD4⁺ CD28⁺ CD57⁺ T cells, or (d) CD8⁺ CD28⁻ CD57⁺ T cells were determined (Pearson correlation)