Late memory skewing of CD4⁺ and CD8⁺ T cells after CBT. The relative proportions of CD4⁺ and CD8⁺ T cells in 4 distinct maturation stages (from least mature to more mature: CD45RA⁺CCR7⁺, CD45RA⁻CCR7⁺, CD45RA⁻CCR7⁻, CD45RA⁺CCR7⁻) were assessed using 6-color flow cytometry. Relative proportions of naive and memory T cells in CB transplant recipients (n = 32) were compared with healthy SCT donors (n = 100). CB transplant recipients had, at baseline and after transplantation, relatively reduced proportions of naive and central memory CD4⁺ and CD8⁺ T cells and greater proportions of effector and late-effector memory (ie, CCR7⁻) T cells. Differences relative to healthy donors were statistically significant at all time points (P < .05).