Is the post-transplantation treatment with AMD beneficial?

Recent data have suggested novel ways to enhance donor cell engraftment by treating transplanted recipients with CXCR4/CXCL12 inhibitors, thereby expanding the biologic potential of these molecules primarily used for mobilization purposes. We tested whether repeated pulse inhibitions of CXCR4/CXCL12 signaling using AMD, an inhibitor of CXCR4/CXCL12 signaling, would enhance engraftment in non-myeloablated murine recipients, similar to data published in a myeloablative setting. We documented an increased proportion of circulating neutrophils (both donor- and host-derived) in the AMD-treated group, but this increase was not kinetically influenced by AMD treatment and multilineage engraftment was not enhanced. Although our results with neutrophils are similar to recent clinical data in neutropenic patients chronically treated with AMD, the absence of multilineage engraftment diverges from data in myeloablated recipients. We conclude that pulses of mobilization by AMD post transplantation do not enhance multilineage engraftment.