The aim of this study was to examine the value of minimal residual disease (MRD) detection by multiparameter flow cytometry (MFC) and real-time quantitative PCR (RQ-PCR) at the early stage after hematopoietic stem cell transplantation for predicting relapse and leukemia-free survival (LFS) in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+-ALL). Patients who maintained complete molecular remission (BCR-ABL <.01%) status at 1 and 3 months were associated with a lower relapse rate (P = .02 and <.001) and better LFS (P = .014 and .013) than were those without a complete molecular remission. Negative MFC at 1, 2, and 3 months was associated with a lower relapse rate (P = .01, .004, and .04, respectively) and better LFS (P = .044, <.0001, and .013, respectively). Multivariate analysis showed that MRD positivity identified by MFC or RQ-PCR at 3 months was an independent risk factor for relapse (hazard ratio [HR], 6.042 (95% confidence interval [CI], 2.283 to 15.988), P < .001), LFS (HR, 3.614 (95% CI, 1.610 to 8.111), P = .002), and overall survival (HR, 2.547, 95% CI, 1.008 to 6.443), P = .048). In summary, MRD detection by MFC and RQ-PCR detection of BCR-ABL at the early stage were important predictors of outcome in patients with Ph+-ALL, and these tests played complementary roles in predicting prognosis.
Keywords: BCR-ABL; Flow cytometry; MRD; Relapse.
Copyright © 2018 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.