Role of pre-transplant MRD level detected by flow cytometry in recipients of allogeneic stem cell transplantation with AML.

Abstract

We analyzed the impact of pretransplant MRD level in bone marrow measured by flow cytometry using "different from normal" method on outcomes for 189 AML patients (108 males; median age, 58 (21-80)years). All patients were subdivided into negative (n=96), "low" (0.1%-0.5%, n=32), and "high" MRD (>0.5%, n=61) groups. In multivariate analysis, the hazard ratios for "high" and "low" MRD levels related to MRD negativity were 7.9 (95% CI 3.5-18.1, P<.001) and 5.4 (95% CI 2.1-14, P=.0058) for relapse; 2.3 (95% CI 1.3-4.1, P=.006) and 1.6 (95% CI 0.82-3.3, P=.16) for OS; and 2.8 (95% CI 1.7-4.7, P<.001) and 2.2 (95% CI 1.1-4.2, P=.02) for LFS, respectively. We found no significant impact of "low" MRD level on relapses (0.68, 95% CI 0.33-1.4, P=.30), OS (0.72, 95% CI: 0.36-1.5, P=.36) and LFS (0.79, 95% CI: 0.42-1.5, P=.46) related to "high" MRD group. Presence of detectable MRD was indicative for a high relapse risk, low LFS and OS. "Low" MRD level showed no significant impact on relapse, LFS and OS related to "high" MRD group.