| Objective: Dynamically monitoring of minimal residual disease(MRD)levels after induction chemotherapy in patients with acute lymphoblastic leukemia(ALL).To explore the relationship between different MRD levels at different time points and relapse of ALL patients and the relationship between different MRD levels and 3-year overall survival at different time pointsMethods: Bone marrow MRD levels were measured by flow cytometry(FCM)in 64 cases with ALL during the 33 rd,12th week,6th,9th,and12 th months of chemotherapy in the first hospital of Lanzhou University from January 2010 to December 2015.According to the MRD levels,they were divided into positive MRD group and negative MRD group,to evaluate whether there was statistic difference in gender,age,subtype,chromosome,fusion gene,white blood cell count and bone marrow image on the 15 th day of chemotherapy in MRD positive and negative groups.Analyse the relationships between MRD levels and relapse in children with ALL at different chemotherapy time points.At the same time,analyse the relationships between MRD levels and 3-year overall survival.Results: 1.There was statistical differences in the white blood cell count,the BCR-ABL and MLL-AF4 fusion genes,the 15 th day of bone marrow chemotherapy,and the risk stratification between MRD positive and negative groups(P<0.05);There was no statistical differences in gender,age,subtype,chromosome,the fusion genes of E2A-PBX1 and TEL-AML1 between MRD positive and negative groups in the incidence of 64 children(P>0.05).2.The relapse rate of MRD positive group was significantly higher than MRD negative group at the 33 th day,the 12 th week and the 6th month of chemotherapy.There was statistical differences between two groups(P<0.05).There was no statistical differences in the relapse rate between the MRD-positive and negative groups at the 9th and the 12 th month of chemotherapy.(P>0.05).3.The early relapse rate of MRD positive group was significantly higher than laterelapse rate in children with ALL at the 33 th day and the 12 th week after chemotherapy.There was statistical differences between two groups(P<0.05).There was no statistical differences in the early and late relapse rates between the MRD positive and negative groups at the 6th,the 9th and the 12 th month of chemotherapy(P>0.05).4.There was statistical differences in the 3-year OS rate between the MRD positive and negative groups at the 33 th day and the 12 th week after chemotherapy in children with ALL(P<0.05).There was no statistical differences in 3-year OS rate between the MRD-positive group and the MRD-negative group at the 6th,the 9th and the 12 th month after chemotherapy(P>0.05).5.There was statistical differences between the relapse and non-relapse of children in the 3-year OS.There was statistical differences between the early and late relapse in the 3-year OS(P <0.05).Conclusions: MRD was dynamically monitored by flow cytometry in 64 patients with bone marrow specimens by retrospective study.MRD could predict the relapse of ALL in the prognosis of ALL.The positive of MRD in patients with ALL on the 33 th day and the 12 th week increases the early relapse rate.The earlier MRD positive time during chemotherapy,the lower 3-year overall survival rate. |
