OBJECTIVETo investigate the presence of leukemia stem cells (LSC) in acute myeloid leukemia (AML) and find out the relative position of leukemia cells in the figures of flow cytometry, and to analyze the relationship between minimal residual diseases (MRD) and the level of LSC, so as to explore the correlation of LSC changes with the curative effect and the prognosis during chemical therapy.

METHODSA total of 85 samples were collected from 50 AML (except M3) patients, including 50 samples from the newly diagnosed patients, 7 samples of AML patients with non-remission and 28 samples of AML patients with complete remission. All samples were used for detection of LSC from immune phenotype of CD34/CD38/CD123 by flow cytometry. The detection of immune phenotypic of leukemia cells was performed in the newly diagnosed patients. The detection of leukemia- associated immune phenotypes (LAIP) was implemented in the non-newly diagnosed patients.

RESULTSThe LSC was identified in the CD34/ CD38/ CD123 in AML and consistent with the relative position of the leukemia cell in flow cytometry figures. Statistical analysis showed significant difference in LSC content between the newly diagnosed AML group and the post-chemotherapy complete remission group(P<0.01),but did not between the newly diagnosed AML group and the post-chemotherapy non-remission group(P>0.05).There was significant positive correlation between the LSC content and MRD level in 28 AML patients with complete remission (r=0.680,P<0.01).

CONCLUSIONLSC exist in AML and the relative position are consistent with the leukemia cells in flow cytometry figures, the size characteristics and weak expression of CD45 are also similar to leukemia cells. The proportion of LSC decreases after chemotherapy. Detecting and tracking the LSC changes in bone marrow and combination with detecting minimal resident disease(MRD) may contribute to evaluate the theraputic efficacy and prognosis of leukemia patients.