慢性B淋巴细胞白血病B细胞B7.2分子表达缺陷的研究

Defective expression of B7.2 in B cell chronic lymphocytic leukemia B cells

目的 研究比较慢性B淋巴细胞白血病 (BCLL)与正常人外周血中B细胞的B7 1、B7 2分子的表达水平 ,探讨其表达与慢性B淋巴细胞白血病发病机制的关系。方法 将 2 3例BCLL患者分为 0～Ⅱ期、Ⅲ～Ⅳ期两组 ,并设正常对照组。乙聚蔗糖 泛影钠淋巴细胞分离液分离出BCLL患者及正常人的外周血单个核细胞 ,体外培养 2 4h后 ,流式细胞仪检测B细胞B7 1、B7 2表达的百分率 ;BCLL组与对照组及 0～Ⅱ期组与Ⅲ～Ⅳ期组间分别进行t检验。结果 与正常对照组相比 ,Bell患者外周血B细胞B7 2分子的表达率 (2 0 %± 13% )明显低于正常人 (5 8%± 12 % ,P <0 0 5 ) ,B7 1单独表达率及B7 1、B7 2同时表达率在正常人与BCLL两组比较差异无显著意义 (P >0 0 5 ) ;BCLL组中 0～Ⅱ期组与Ⅲ～Ⅳ期组B7 2的表达率分别为 2 5 %± 17%及 17%± 8% (P >0 .0 5 )。结论 外周血B细胞B7 2分子的表达存在缺陷 。

Objective To investigate the expression of B7.1 and B7.2 molecules in peripheral B cells of patients with chronic B cell lymphocytic leukemia (BCLL) and to study the relationship between B7.1 and B7.2 expression and pathogenic mechanism of BCLL. Methods Peripheral blood mononuclear cells (PBMC) were separated by Ficoll Hypaque lymphocytes separation medium from 25 normal persons (normal control group) and 23 BCLL patients (BCLL group) which were further divided into two groups, phase 0～II group and phase III～IV group. Flow cytometry (FCM) was used to analyze the B7.1 and B7.2 expression in peripheral B cells after the mononuclear cells had been cultured for 24 hours in vitro. Results The B7.2 expression in B cells of BCLL patients was significantly lower than that in normal control group ( P <0.05). No statistically significant difference was found in the B7.1 expression and co expression of B7.1 and B7.2 between the BCLL group and normal control group. The average B7.2 expression rates in patients of phase 0～II group and phase III～IV group were 25%±17% and 17%±8% respectively without statistically significant difference. Conclusion The B7.2 expression in B cell of patients with BCLL is defective, which may be one of the pathogenic mechanisms of chronic BCLL and a major cause why the body fails to clear the BCLL cells via immunological means.