Peripheral CD4⁺ T cells have been efficiently restored and contain an increased proportion of activated/effector memory CD4⁺ T cells compared with healthy control patients. CD4⁺ T-cell numbers and frequencies of effector memory cells (EM), central memory cells (CM), recent thymic emigrants (RTE), and central naive cells (CN) within CD4⁺ T cells (A) during the course of immune reconstitution after CCR5Δ32/Δ32 SCT and (B) in SCT controls (27.5 ± 7 months after transplantation) compared with healthy patients were determined in fresh whole blood. Median CD4⁺ T-cell numbers of healthy patients is indicated by the thick horizontal line, and the dashed horizontal lines denote the normal 25th and 75th percentiles in panel A. The horizontal lines in panel B denote the median values of each group. Statistical significances are given for comparisons between healthy control values and SCT control values (*P < .05, **P < .01, ***P < .001). (C) CD4⁺ T-cell expression of the activation markers CD38, HLA-DR, and CD49d and the proliferation marker Ki67 at 9.5 and 24 months after CCR5Δ32/Δ32 SCT in comparison with SCT control and healthy control patients. Data are representative for 5 SCT control and 4 healthy control patients.