Figure 1

(a) CD34 + cell and CD3 + T-cell content in the graft using capping of T cells to a maximum T cells of 600 million/kg of recipient weight is shown. Excess CD34 + cells and T cells grafted using T-cell capping method rather than CD34 + capping at 5 million/kg are also shown. 1 (b) The primary outcome measure of CD4+ T-cell reconstitution at day + 90 and day + 180 is shown. The patients who did not meet the outcome measure are shown in red, and the connecting lines between day + 90 and day + 180 are shown to indicate the trend of CD4+ T-cell reconstitution. 1 (c) Percent of naïve versus central memory + effector memory + terminal differentiated (CM + EM + TD) CD4+ T cells and percent of CD4+ recent thymic emigrants (RTEs) in 4 children are shown. Circulating naïve CD4+ T cells and RTEs were absent at 3 months post-transplant confirming the differential effect of alemtuzumab on naïve and memory-effector-terminal differentiated subsets. Naïve T-cell reconstitution at 6 and 9 months correlated with the emergence of RTEs suggesting naïve T-cell reconstitution is via thymic output. 1 (d) Correlation between graft T-cell dose and CD4 reconstitution (at 90 days) in 18 patients who did not receive steroids is shown. A direct correlation was observed in patients not receiving steroids excluding the one outlier (a patient with aplastic anemia shown in blue) that developed early mixed chimerism and had received lowest T-cell dose of 90 million/kg. 1 (e) There was no correlation between graft T-cell dose and CD4 recovery in 8 patients receiving steroids. Seven patients were treated with a short course of systemic steroids (one to three weeks) for engraftment syndrome (n = 1); autoimmunity (n = 1) and acute GvHD (grade 1 skin; n = 5). One patient with acute GvHD (skin and gut; grade 3) required immunosuppression (including steroids, etanercept and ruxolitinib) for a total of 458 days.