[Clinical Significance of Minimal Residual Disease Monitoring by Multi-parameter Flow Cytometry before Allogeneic Hematopoietic Stem Cell Transplantation for Prognosis of Acute Leukemia Patients].

Objective: To investigate the clinical significance of minimal residual disease (MRD) monitoring by multiparameter flow cytometry (MFC) before allogeneic hematopoietic stem cell transplantation (allo-HSCT) in acute leukemia.
Methods: 81 cases of patients with AL treated with allo-HSCT in Department of Hematology, the First Affiliated Hospital of Chongqing Medical University form July 2015 to July 2018 was selected and retorspectively analyed. of which 79 patients were in CR and two patients were in non-CR. The CR group was further divided into two groups of MRD ⁺ and MRD ^- based on the MRD level prior to HSCT.
Results: Among 81 patients, there were statistically significant differences in the three-year overall survival(OS) (CR 82.2%: NCR 0%), cumulative relapse incidence(RI) (CR 17.7%; NCR 100%) and leukemia-free survival rate(LFS) (CR 42.3%: NCR 0%) between CR and NCR group(P<0.05). Among 79 CR patients, MRD was negative in 30 patients while positive in 49 patients, there was significant differences in the three-year overall survival between MRD ^- and MRD ⁺ group. The results of univariate analysis showed that the MRD ⁺ group showed lower LFS compared with that of MRD ^- group （10.5% vs 36.2%）(P＜0.001，95%CI).
Conclusion: MRD ^- patients shows longer LFS as compared with that of MRD ⁺ patients, therefore, MRD monitoring by MFC before allo-HSCT is very important for the prognosis of the AL patients.