Relationship between donor source, pre-transplant measurable residual disease, and outcome after allografting for adults with acute myeloid leukemia.

Lack of HLA-matched related/unrelated donor remains a barrier to allogeneic hematopoietic cell transplantation (HCT) for adult acute myeloid leukemia (AML), with ongoing uncertainty about optimal donor type if more than one alternative donor is available. To assess the relationship between donor type, pre-HCT measurable residual disease (MRD), and post-HCT outcomes, we retrospectively analyzed 1265 myelodysplastic neoplasm (MDS)/AML and AML patients allografted in first or second remission with an HLA-matched sibling (MSD) or unrelated donor (MUD), HLA-mismatched unrelated donor (MMD), an HLA-haploidentical donor, or umbilical cord blood (UCB) at a single institution. Relapse risk was non-significantly higher after HLA-haploidentical and lower after UCB HCT.

Measurable Residual Disease as Predictor of Post-Day +100 Relapses Following Allografting in Adult AML.

Measurable residual disease (MRD) by multiparametric flow cytometry (MFC) before allogeneic hematopoietic cell transplantation (HCT) identifies patients at high risk of acute myeloid leukemia (AML) relapse, often occurring early after allografting. To examine the role of MFC MRD testing for the prediction of later relapses, we examined 935 adults with AML or myelodysplastic neoplasm (MDS)/AML transplanted in first or second morphologic remission who underwent bone marrow restaging studies between day 70 and 100 post-HCT and were alive and without relapse by day +100. Of these 136 (15%) had MRD before HCT, whereas only 11 (1%) had MRD at day +70-100.