IRIS patients display a distinct activation status during reconstitution after ART therapy. The percentage of naive (CD45RO⁻CD27⁺; A) effector memory (CD45RO⁺CD27⁻; B) and HLA-DR⁺ (C) cells within CD4⁺ T lymphocytes, and Ki67⁺ cells within central memory CD4⁺ T lymphocytes (D) in HIV⁺ controls (open symbols) and HIV⁺ IRIS patients (filled symbols) were measured before and during ART. The shaded area represents the IQR of the time of initiation of IRIS episode. Dotted lines represent median values of the given measurements in healthy donors. Representative dot plots showing proportions of naive (Nv), central memory (CM), effector memory (EM), and effector (Ef) CD4⁺ T cells (E) and frequencies of Ki67⁺ cells within central memory CD4⁺ T lymphocytes (F) from a single HIV⁺ non-IRIS (left panel) and a single HIV⁺ IRIS patient (right panel) are shown.