Figure 1.

Extended post-transplant follow-up enhances the detection efficiency of human acute myeloid leukemia cell engraftment in NSG mice. Longitudinal engraftment analysis by routine bone marrow punctures performed every 4 weeks revealed dependency of engraftment efficiency on post-transplant follow-up time. Lower percentages of engrafted mice were detected at standard post-transplantation analysis time-points used in previous protocols as shown by (A) quantification of engrafted samples at 8–10 weeks, 12–14 weeks and 16 weeks versus 1 year and by (B) Kaplan-Meier survival analysis of 109 mice xenotransplanted with human AML cells, indicating that with extended follow-up time, ~95% of all transplanted mice develop leukemia. A Fisher exact test was used to calculate statistical significance between engrafters and non-engrafters at each analyzed time to our endpoint of 1 year of observation in (A).