The Clinical Significance Of Monitoring The Minimal Residual Disease Dynamically In Acute Leukemia By Multiparameter Flow Cytometry And WT1 Gene Expression

Objective To explore the clinical significance of minimal residual disease(MRD) monitored by flow cytometry(FCM) dynamically in patients with acute lymphocytic leukemia(ALL);To explore the significance of MRD and WTl gene monitored by FCM and Real time quantitative PCR(RT-PCR)dynamically in patients with acute myeloid leukemia(AML).Methods 302 bone marrow specimens of 44 patients with ALL were detected the MRD by FCM after complete remission(CR) by first induction chemotherapy and each consolidation chemotherapy, the change of bone marrow cell morphology was detected at the same time;63 bone marrow specimens from 63 patients with AML were detected WT1 gene expression level before induction chemotherapy(and 50 bone marrow specimens from 50 healthy were detected) by RT-PCR,256 bone marrow specimens of 42 patients with AML were detected the MRD by FCM and256 bone marrow specimens of these patients were dected the WT1 gene expression level by RT-PCR,the change of bone marrow cell morphology was detected at the same time.Results1)The recurrence rate of patients with ALL was signifieantlv higher in patients with bone marrow MRD>1% than that in those with MRD ≤1% after CR1(P<0.005));2)The patients with ALL associated with high risk factors are more likely to appear MRD> 1% than those with no risk factors after CR1(P = 0.034, < 0.05);3) the recurrence rate of patients with ALL was no statistically significant difference no matter whether associated with high risk factors if the MRD always≤1%after CR1(P=0.565, >0.05);4) WT1 gene is highly expressed before induction therapy in patients with AML,high expression rate is 93.7%;WT1 expression level drop down after induced therapy,WTl expression level of patients with CR1 was significantly lower than thatof patients without induce therapy(P = 0.001, < 0.05);WT1 gene don’t express or very low expression in healthy people;5)The recurrence rate was signifieantlv higher in patients with bone marrow WT1>110 cobies than that in those with WT1 ≤110 cobies(P=0.001,<0.05);6)The recurrence rate of patients with AML has no obvious statistical significance in patients with bone marrow MRD>1% and that in those with MRD≤1%(P=0.072,>0.05);7)The expression level of WTl in patients with CR1 had positive con’elation with the level of MRD(r=0.472,P=0.001). The recurrence rate of patients with AML with both low level of MRD and WTl was significantly lower than those of either high level of MRD and WTl(P=0.014,<0.05)Conclusions1)Bone marrow MRD > 1% in patients with ALL after CR1 means high recurrence rate, the bone marrow MRD is one of the important indicators monitoring ALL remission and prompt relapse,using MFC monitoring MRD dynamically may provide the basis for clinical individual therapyin.2)The patients with ALL associated with high risk factors are higher probability to appear MRD> 1% than those with no risk factors after CR1;the recurrence rate of patients with ALL was no statistically significant difference no matter whether associated with high risk factors if the MRD always≤1% after CR1;3)WT1 gene is highly expressed before induction therapy above 95% patients with AML;WT1 gene don’t express or very low expression in healthy people;WT1gene expression level is closely related to the treatment effect after induction in patients with AML;4)The expression level of WTl in patients with CR1 had positive correlation with the level of MRD,conbine these can evaluate the detection-rate of residual tumor cells among patients with AML and increasing the accuracy of prompt relapse,provide clinical significance for the individual treatment.