Pretransplantation risk factors for positive MRD after allogeneic stem cell transplantation in AML patients: a prospective study.

We aimed to prospectively explore the risk factors for measurable residual disease (MRD) positivity after allogeneic stem cell transplantation (allo-SCT) in AML patients (n = 478). The cumulative incidences (CIs) of post-SCT MRD positivity at 100 days, 360 days and 3 years were 4.6%, 12.1% and 18.3%, respectively. Positive pre-SCT MRD and pre-SCT active disease were risk factors for post-SCT MRD positivity at both 360 days and 3 years (P < 0.001). European LeukemiaNet (ELN) 2017 risk stratification was a risk factor for positive post-SCT MRD at 360 days (P = 0.044). A scoring system for predicting post-SCT MRD positivity at 360 days was established by using pre-SCT MRD, pre-SCT active disease and ELN 2017 risk stratification. The CI of positive post-SCT MRD at 3 years was 13.2%, 23.7%, and 43.9% for patients with scores of 0, 1, and 2, respectively (P < 0.001). Multivariate analysis demonstrated that the scoring system was associated with a higher CI of post-SCT MRD positivity, leukemia relapse and inferior survival. Our data indicate that positive pre-SCT MRD status, pre-SCT active disease, and ELN 2017 risk stratification are risk factors for positive post-SCT MRD status in AML patients.