Different size and distribution of donor-derived CD56^brightCD16^−/low, CD56^dimCD16⁺, and CD56⁻CD16⁺ subsets in NK cells reconstituting after intrabone UCBT. (A) Fresh NK cells, collected at the indicated time intervals from recipients of a transplant, were analyzed by double immunofluorescence and FACS analysis for the expression of CD56 and CD16. Three different patients are shown. Dotted lines in the plots separate CD56^bright from CD56^dim NK-cell subsets. The percentage of each subset is indicated in the different quadrants. (B) For comparison, the distribution and relative percentage of the CD56^brightCD16^−/low, CD56^dimCD16⁺, and CD56⁻CD16⁺ NK-cell subsets are shown for NK cells isolated from representative healthy adult peripheral blood (left) and CB (right). (C-D) The differential development of the CD56^negCD16⁺ (C) and the CD56^bright (D) NK-cell subsets are shown as 95% CIs for the mean at 1, 3, 6, and 12 months after UCBT in the 3 groups of patients (Top, group 1 ●; middle, group 2 ■; bottom, group 3 ▴). In each panel the 95% CI for the mean is reported for healthy adult (□) and CB (○) NK-cell subset. (E) The percentage of CD56⁻CD16⁺ in group 1 (black histograms) and group 2 (white histograms) patients is shown as 95% CI at 6 and 12 months after UCBT. Statistical significance is indicated (*P < .05).