Figure 2. Clinical grade culture of CB progenitors with Delta1^ext-IgG results in significant in vitro expansion of CD34⁺ cells and more rapid neutrophil recovery in a myeloablative double CBT setting.

CD34⁺ cord blood progenitor cells were enriched and placed into culture with Delta1^ext-IgG as described. (a) The mean fold expansion for both total nucleated cells (TNC) and CD34⁺ cells upon harvest is presented. Data shown in the bar graph are the mean ± sem for the ten patients enrolled to date (range in parentheses). (b) The individual and median times (solid line) to absolute neutrophil counts (ANC) of ≥500 μl⁻¹ for patients receiving double unit CB transplants with two non-manipulated units (“conventional”) versus with one ex vivo expanded unit and one non-manipulated unit (“expanded”) is presented. (c) The absolute neutrophil count and specific donor CB unit contribution to myeloid engraftment over time (x axis, days 0 to 80) determined by ampFLP analysis are presented. The bars indicate percent expanded (hatched gray) or non-manipulated (white) unit contributing to myeloid (CD33⁺) engraftment (left axis) weekly through day 28 (day 7, 14, 21 and 28) post transplant and then at day 56 and 80. Eight of ten evaluable patients are presented (see results). The left column represents patients who achieved an ANC of ≥500 μl⁻¹ when the expanded unit was the dominant donor while the right column represents patients who had converted to the non-manipulated donor when the ANC reached ≥500 μl⁻¹. The solid line represents ANC over time (right Y axis). Individual time to ANC ≥500 μl⁻¹ is shown to the left of each graph.