T-cell reconstitution after haplo-HCT and MD-HCT. (A) Peripheral blood reconstitution of CD4⁺ Tcon, CD4⁺ Treg, and CD8⁺ T cells after transplant; the median cell counts per microliter are represented at each time point. (B) Median CD4/CD8 and Treg/Tcon ratio after HCT. (C) Heat map summarizes T-cell reconstitution during the first year after HCT. Absolute median counts were scaled for the lowest and highest values in each group. Red denotes the highest value and blue denotes the smallest value in each group. (D) Flow cytometry plots from 2 representative patients (haplo-HCT and MD-HCT) showing PD-1 expression on T-cell subsets; CD4⁺ Tcon naive cells were used as internal negative control. (E) Expression of PD-1 on CD4⁺ Tcon, CD4⁺ Treg, and CD8⁺ T cells after haplo-HCT and MD-HCT. Values are expressed as median and range. Treg cells were defined as CD4⁺CD25⁺CD127⁻ T cells and Tcon cells as CD4⁺ conventional (non-T regulatory) T cells. Naive T cells are CD45RO⁻CD62L⁺ lymphocytes; CM T cells are CD45RO⁺CD62L⁺ lymphocytes; TEMRA T cells are defined as CD45RO⁻CD62L⁻ lymphocytes and EM T cells are CD45RO⁺CD62L⁻ lymphocytes. Haplo-HCT, n = 60; MD-HCT, n = 35. Asterisks denote statistically significant differences comparing haplo-HCT and MD-HCT cohorts at specific time points (****P < .0001; ***P < .001; **P < .01; *P < .05). White stars within the heat map (C) denote P < .05 (Wilcoxon rank-sum test). See supplemental Table 8 for the median absolute values along with the corresponding interquartile values and P values for panels A-C.