Expression Of Costimulatory Molecule B7-H3 On Blaste Cells Of Human Acute Leukemia And Its Clinical Significance

Objective: To analyze the expression of costimulatory molecule B7-H3 (CD276) in the human acute leukemia patients, and explore the clinical significance of the expression of B7-H3.Methods: The expression of B7-H3 protein was detected by FCM and the expression of B7-H3 mRNA was detected by RT-PCR. We analyzed the relationship between the expression of B7-H3 and some clinical factors, for example: the sex, the age, WBC counts, bone marrow blast cells, the expression of CD34 in the blast cells and the karyotype. We evaluated the Progression-free Survival (PFS) and Overall Survival (OS) between B7-H3+ group and B7-H3- group.Results: We analyzed the expression of B7-H3 on leukemic cells of bone marrow from AL patients by FCM analysis and RT-PCR. The results demonstrated that B7-H3 was weakly expressed on bone marrow of AL patients, and RT-PCR also detected mRNA of B7-H3. Among the 59 cases of B7-H3+AL, 50.8%(30/59)was weakly expressed (12% to 20%) , 30.5%(19/59) was medium (20% to 40%), and 18.6%(11/59) of cases was high. However, no B7-H3 positive cells were detected in the normal human bone marrow. No statistical difference was found between the expression and some clinical factors except the expression of CD34 and the karyotype. Moreover, the expression of B7-H3 was significantly highly in CD34 positive group than that in CD34 negative group. In addition, the expression of B7-H3 was higher in poor-risk cytogenetics group than that in Better-risk cytogenetics group and intermediate-risk cytogenetics group(P<0.05), but there was no statistical difference between Better-risk cytogenetics group and intermediate-risk cytogenetics group(P> 0.05). The expression of B7-H3 in B-ALL was the highest in AL but there was no statistical difference between B-ALL and other AL subtypes(P>0.05). There was also statistical difference in PFS(7.4 mouths and 15.2 mouths)and OS(9.8 mouths and 17.8 mouths) between B7-H3 positive group and B7-H3 negative group(P<0.05). Conclusion: The expression of B7-H3 in AL has relationship with the expression of CD34 and the karyotype. The B7-H3 positive patients have shorter overall survival and shorter PFS. The research of B7-H3 may be a new prognostic marker and provide insights into the leukemogenesis of acute leukemia.