Abstract: Objective: To observe the influence of the CD96 and CD71 expressions in the surface of leukemia stem cells (LSC) in the therapeutic effects and prognosis of the children with acute leukemia,and to clarify the relationships between the molecular biological characteristics of LSC in the children with leukemia and their therapeutic effects and prognosis.Methods: Eighty children with acute leukemia were selected as the subjects. Among them, 39 cases were acute lymphoblastic leukemia (ALL) and 41 cases were acute myeloid leukemia (AML). The CD96 and CD71 expressions on the surface of LSC were detected with flow cytometry; the therapeutic effects of the first cycle chemotherapy, the survival rate of 5-year, the incidence of infection after chemotherapy, the recurrence rate after chemotherapy, and the incidence of extramedullary infiltration of the children were observed and compared.Results: The CD96 expression on the surface of LSC was positive in 38 cases (47.5%) and the CD71 expression on the surface of LSC was positive in 45 cases (56.3%);the difference of positive expression rates of CD96 and CD71 was not significant (χ²=1.227, P=0.268). The positive expression rates of CD96 and CD71 on the surface of LSC of the children with AML were significantly higher than those in the children with ALL, and the differences were statistically significant (χ²=22.225, χ²=34.028, P<0.01). The distribution of therapeutic effects and the clinical efficiency of the first cycle chemotherap, in the children with negative CD96 expression on the surface of LSC were superior to those with positive CD96 expression on the surface of LSC; the distribution of therapeutic effects and the clinical efficiency of the first cycle chemotherapy in the children with negative CD71 expression on the surface of LSC were superior than those with positive CD71 expression on the surface of LSC; the differences between two groups were statistically significant (χ²=11.323, χ²=16.589, P<0.05; U=2.939, U=2.291, P<0.05). The survival rate of 5-year in the children with negative CD96 expression on the surface of LSC was higher than those with positive CD96 expression; the incidence of infection after chemotherapy,the recurrence rate after chemotherapy and the incidence of extramedullary infiltration were lower than those with positive CD96 expression. The incidence of infection after chemotherapy and the recurrence rate after chemotherapy in the children with negative CD71 expression on the surface of LSC were lower than those with positive CD71 expression,and the differences between two groups were statistically significant (χ²=5.051,χ²=13.288, P<0.05).Conclusion: The expressions of CD96 and CD71 on the surface of LSC in the children with acute leukemia has relationship with the subtypes of the disease and the therapeutic effects of the first cycle chemotherapy, which can be used as markers for the diagnosis and evaluation of therapeutic effects. The expression level of CD96 is related to the prognosis of the patients, which can be used as an indicator for predicting the prognosis of patients.

Key words: CD71, acute leukemia, prognosis, leukemia stem cells, CD96, therapeutic effects