Quantitative detection of minimal residual leukemia cells in peripheral blood and clinical application

Objective To explore the clinical application significance of quantitative detection of minimal residual leukemia cells in peripheral blood in acute leukemia patients.Methods Using PCR amplification of quantitative method of limited dilution,the FLT3 gene was detected in blast cells of peripheral blood from 25 newly diagnosed cases of acute leukemia,and the number of minimal residual leukemia cells in newly diagnosed cases and the cases after one course of chemotherapy was calculated respectively.10 healthy subjects were used as control group.Results ①The positive rate of FLT3 gene in 25 newly diagnosed cases of acute leukemia sample was 80%(20/25),the positive rate in acute myeloblastic leukemia(AML) patients was 88.2%(15/17)and in acute lymphocytic leukemia(ALL)was 62.5%(5/ 8).②The mean DNA content in peripheral blood in 20 cases with FLT3 positive expression in newly diagnosed group was(2.36±1.25)×108 μg·L-1,being equal to(18.66±8.79)×106 leukemia cells in every microliter peripheral blood.After one course of chemotherapy ,there was 1 case without remission,the DNA content in peripheral blood was 1.69×107μg·L-1,being equal to 1.01×106 leukemia cells in every microliter peripheral blood;there were 3 cases with partial remission,the mean DNA content in peripheral blood was(0.57±0.24)×106 μg·L-1,being equal to(1.82±0.19)×103 leukemia cells in every microliter peripheral blood.There were 9 cases with complete remission with FLT3 negtive expression,and 7 cases with complete remission with FLT3 positive expression,the mean DNA content in peripheral blood was(0.16±0.06)×106 μg·L-1,being equal to(1.86±1.31)×102 leukemia cells in every microliter peripheral blood.Conclusion The quantitative and periodic detection of minimal residual leukemia cells would help to evaluate leukemia chemotherapy efficiency and to adjust treatment scheme in time.