Minimal Residual Disease Monitoring Of Acute Leukemia With Complete Remission And Its Significance

Background:Complete remission of acute leukemia is:clinical symptoms and signs disappeared;normal blood image,the level of blast cells in the bone marrow is less than 5%.However,there are lots of leukemic cells still existed which could not be detected by conventional microscopy.It is called minimal residual disease(minimal residual disease,MRD).MRD is the course of relapse.As an independent prognostic factor and part of criteria of CR,MRD promotes the morphology level of leukemia to the molecular level.It is important to monitor quantification of MRD during clinical remission period.Objectives:To observe the level of MRD in acute leukemia patients with complete remission and explore the role of monitoring MRD in relapse and its significance.Methods:Acute leukemia patients:51 cases of adult acute lymphoblastic leukemia with complete remission(CR)patients(male:37 cases,female:14 cases)and 132 cases of adult acute myeloid leukemia with complete remission(male:77 cases,female:55 cases),were observed,detected the MRD by flow cytometery,and morphology by light microscopy at the same time.The average follow-up period was 6 months(3 months to 25 months).The average MRD level was got,and the role of MRD predicting relapse was assessed in these patients.Results:MRD of the 51 cases of ALL patients:B-ALL maximum was 8.83%,the average was 0.716%,T-ALL maximum was 1.21,the average was 0.262%.MRD of 132 cases of AML patients:the average was 1.002%,the maximum was 11.82%,the minimum was 0.009%.There were 20 cases of relapsed ALL patients and 25 cases of relapsed AML patients.When MRD＞0.1%,the rate of relapse was significantly increased. Conclusions:MRD detection by FCM is a large range(10^-5 10^-2),which can not be used as a single indicator of complete remission.MRD could be used as sensitive indicator for prognosis.The possibility of relapse is increased when MRD≥0.1%. When MRD≥1%,the disease might be relapsed within 3 months.