[Early detection of MRD in peripheral blood after induction chemotherapy of newly diagnosed patients with AML and its correlation with curative effects].

The purpose of this study was to detect the minimal residual disease (MRD) in peripheral blood of newly diagnosed patients with acute myeloid leukemia (AML) on day 8 of induction chemotherapy and analyze the correlation between day 8 MRD (D8RD) and therapeutic effectiveness. 29 adult patients (13 males and 16 females, aged 16 - 75 years, median 41 years) with AML diagnosed and treated in West China Hospital from September 2009 to June 2010 were analyzed and followed up in the study. The leukemia-associated aberrant immunophenotype (LAIP) of all the patients were detected by multiparameter flow cytometry (FCM) before therapy. The level of MRD in the peripheral blood at day 8 of induction chemotherapy was detected by FCM based on the LAIP. The overall survival curve was drawn by calculation using Kaplan-Meier method using, and the comparison between different groups was carried out by Log-rank test. The results indicated that after first course therapy, the levels of peripheral D8RD in 7 out of 29 AML cases were lower than 0.01% (negative group), and that in another 22 cases were higher than 0.01% (0.08% - 55%, positive group). The sex, age, WBC, LDH, percentage of bone marrow blasts at diagnosis in these groups were not statistically different. 6 cases achieved CR (86%) in D8RD negative group, and also 6 cases achieved CR (27%) in D8RD positive group, CR rate in D8RD negative group was higher than in D8RD positive group (86% vs 27%, P < 0.05). The median follow-up of 29 cases lasted for 15 months; the 1-year overall survival rate of D8RD negative and D8RD positive groups was 100% and 39.4%, respectively (P < 0.01). It is concluded that MRD level in peripheral blood at day 8 of induction chemotherapy is an early index to predict clinical efficacy of induction therapy in AML.