Clinical Significance Of Monitoring Minimal Residual Disease By Multi-parameter Flow Cytometry In Adult B-cell Acute Lymphoblastic Leukemia

Objective:Our aim is to find the optimal threshold of MRD, to explore the clinical value of MRD in adult B-cell acute lymphoblastic leukemia which monitored by multi-parameter flow cytometry and to discuss whether the optimal threshold could predict relapse, prognosis and guide individual treatment.Methods:In a retrospective study, a total of 100 adult adult B-cell acute lymphoblastic leukemia patients, from the First Affiliated Hospital of Soochow University during June 1,2008 to June 30,2011, were recruited. The MRD of 100 adult B-cell acute lymphoblastic leukemia patients which were detected by multi-parameter flow cytometry monitored consecutively during the introduction and consolidation therapy.Results:1. In 14 days induction therapy, low risk group (MRD< 10-3) 23 patients, median RFS 27.22±17.896 months, including:RFS< 12 months in 3 patients (13%), RFS 12 months or more 20 cases (87.0%).High-risk groups (MRD> 10-3) 38 patients, median RFS 11.82±1.239 months, including:RFS< 12 months 23 cases (60.5%), RFS 12 months or more 15 cases (39.5%);P= 0.000.2.28 days in induction therapy, low risk group (MRD< 10-3) 46 patients, median RFS 21.13±.080 months, including:RFS<12 months in 15 patients (32.6%),RFS 12 months or more 31 cases (67.4%);Hig-risk groups (MRD> 10-3) 18 patients, median RFS 9.28±8.094 months, including:RFS< 12 months 12 cases (66.7%),12 months RFS or more 6 cases (33.3%);P= 0.023.3.16 weeks after treatment, low risk group (MRD< 10-3) 41 patients, median RFS 23.39±15.862 months, including:RFS<12 months in 8 patients (19.5%),RFS 12 months or more 33 cases (80.5%);High-risk groups (MRD> 10"3) 17 patients, median RFS 5.59±2.980 months, including:RFS< 12 months 15 cases (88.2%),12 months RFS or more 2 cases (11.8%);P= 0.000. 4.28 weeks after treatment, low risk group (MRD< 10-3) 35 patients, median RFS 24.63±16.707 months, including:RFS<12 months in 8 patients (22.9%),RFS 12 months or more 27 cases (77.1%);High-risk groups (MRD> 10-3) 14 patients, median RFS 8.43±3.228 months, including:RFS< 12 months 9 cases (64.3%),12 months RFS or more 5 cases (35.7%);P= 0.009.Conclusion:In conclusion, adult B-ALL patients who had a positive or consecutively positive of MRD strongly suggest that the risk of relapse is increasing significantly with a shorter relapse-free survival and overall survival time. So, we can conclude that MRD monitoring by multi-parameter flow cytometry in adult B-cell acute lymphoblastic leukemia was a clinical useful index monitored during the course of treatment, which could predict relapse, prognosis and guide individual treatment.