SLE患者外周血B细胞B7RP-1的表达及其与疾病活动度的相关性

Expression of B7-related protein-1 on B lymphocytes in peripheral blood from patients with sy temic lupus erythematosus and its relationship with disease activity

目的探讨SLE患者B细胞分化和B7相关蛋白-1（B7RP-1）在B细胞上的表达。方法用三色流式细胞仪检测23例初发SLE患者和16例正常人对照浆细胞、记忆性B细胞、原始B细胞的百分比，并检测三类B细胞上B7RP-1的表达量；同时收集患者临床资料，进行SLE疾病活动度指数（SLEDAI）评分，分析疾病活动度与B7RP-1表达水平的关联。结果活动期和非活动期SLE患者浆细胞所占比例较正常人对照显著增加（P〈0．01），且活动期高于非活动期（P〈0．01）；相对于正常人对照，活动期SLE患者记忆性B细胞所占比例减少（P〈0．01），非活动期同正常人对照组差异无统计学意义；原始B细胞所占比例三组间差异无统计学意义。SLE肾炎组浆细胞所占比例高于非肾炎组（P〈0．05），记忆性B细胞和原始B细胞两组差异无统计学意义。SLE患者B细胞B7RP-1表达（46．51％）低于正常人对照组（63．75％），且三种类型B细胞B7RP-1表达量均低于正常人（P〈0．01），但活动期和非活动期患者B7RP-1的表达差异无统计学意义。SLE患者B7RP-1的表达同疾病活动度无关联（r＝0．035，P〉0．05），狼疮肾炎和非狼疮肾炎组B7RP-1表达差异无统计学意义。结论SLE患者外周血浆细胞所占比例增加，B7RP-1的表达下降，可能与SLE的发病机制有关。

Objective To explore the differentiation of B lymphocytes and expression of B7-related protein-1 （B7RP-1） on B lymphocytes in patients with systemic lupus erythematosus （SLE）. Methods Three-color immunofluorescent staining and flow cytometric assay were used to analyze the frequency of three types of B lymphocytes, i.e., plasma cells, memory B lyphocytes and naive B lymphocytes, as well as the expression of B7RP-1 on these cells in peripheral blood from 23 patients with SLE and 16 normal human controls. Clinical data of these patients with SLE were collected, and SLE disease activity index （SLEDAI） was also evaluated. The relationship was assessed between the expression of B7RP-1 and SLEDAI. Results The frequency of plasma cells was highest in patients with active SLE, followed by patients with inactive SLE and normal human controls （P 〈 0.01 ）. A significant decrease was observed in the frequency of memory B lymphocytes in patients with active SLE compared with normal controls （P 〈 0.01 ）, but no significant difference was found between patients with inactive SLE and those with active SLE （P 〉 0.05 ）. Regarding the frequency of naive B lymphocytes, there was no significant difference among the three groups. Increased frequency of plasma cells was also noted in patients with lupus nephritis （LN） compared with those without LN [ （6.15 ± 3.12 ）% vs （3.31 ± 1.41 ）%, P 〈 0.05 ）, but no significant difference was found with regard to the frequency of memory or naive B lymphocytes between these two groups. The expression rate of B7RP-1 was significantly lower on total lymphocytes from patients with SLE than from normal human controls （46.51% vs 63.75%, P 〈 0.05）, which was the case with B7RP-1 on plasma cells, memory B lyphocytes and naive B lymphocytes （all P 〈 0.01 ）, whereas no significant difference was found between patients with inactive SLE and active SLE or between patients with and without LN. In addition, no correlation was found between the expression of B7RP-1 and SLEDAI （r = 0.035, P 〉 0.05）. Conclusions In peripheral blood of patients with SLE, the frequency of plasma ceils is increased, while the expression of B7RP-1 on lymphocytes is decreased, which may be relevant to the pathogenesis of SLE.