Abstract: Objective To investigate the relationship between fusion gene expression and immunological phenotype,we carried out retrospective analysis of data from 109 B cell-malignancy cases. Methods Real-time quantitative PCR assay was used for detection of fusion genes,and immunological phenotype was analyzed by multi-parameter flow cytometry. Results Of the 109 B-ALL cases,98 patients were 1~10 years old. A total of 42 cases（38.5%） were positive for fusion gene,among which TEL/AML1 is most frequent（64.3%）; For immunophenotype,81 cases（74.3%） were type II common-B-ALL which is CD34⁺CD10⁺. Those with TEL/AML1 or BCR/ABL fusion gene were all of this type; Expression of myeloid antigen was not associated with prognosis of the disease. In contrast,different fusion gene expression was related to variable efficacy of clinical therapy. Conclusion Onset age,fusion gene and immunophenotype of acute B-ALL are related to each other. Changes of specific immune markers predict expression of fusion gene in early stage of the disease,and a characteristic fusion gene will benefit an accurate diagnosis and treatment.

Key words: Acute B-lymphoblastic leukemia, Fusion gene, Immunophenotype