系统性红斑狼疮患者外周血T细胞CTLA-4表达及其临床意义的研究#

目的：研究系统性红斑狼疮（Systemic Lupus Erythematosus, SLE）T细胞中CTLA-4的表达及临床意义。 方法：分离正常人和SLE患者的外周血单个核细胞（PBMCs），以抗-CD3、抗-CD28刺激培养48h，刺激培养前后收取细胞，以流式细胞术（FCM）检测CD4+和CD8+T细胞中CTLA-4+细胞比例，并分析其与SLE疾病活动性指数（SLE Disease Activity Index，SLEDAI）和肾损害的关系。再以ELISA法检测培养上清中游离的CTLA-4水平。 结果：SLE患者刺激前的CD4+和CD8+T细胞中、主要是CD25+T细胞中CTLA-4+细胞的比例较正常人显著增高，且与SLEDAI呈正相关；而其CD8+CD28- T细胞中CTLA-4+细胞比例也显著高于正常人，但与SLEDAI之间无显著相关性；经抗-CD3、抗-CD28抗体刺激后，其CD4+CD25+T细胞、CD8+CD25+T细胞或CD8+CD28- T细胞中CTLA-4+细胞的比例却显著低于正常人，但与SLEDAI之间无显著相关性，仅在活动性SLE患者中有肾损组的CD8+CD28- T细胞中CTLA-4+细胞的比例显著低于非肾损组；而且经刺激培养后SLE患者PBMC上清中游离的CTLA-4水平也显著低于正常人。结论：SLE患者新鲜分离的T细胞（CD4+及CD8+）中CTLA-4表达异常增高，反映T细胞异常活化和疾病活动；另一方面，SLE患者T细胞又存在CTLA-4诱导性表达障碍，可能与SLE T细胞体外再活化的能力减弱有关。

The expression of CTLA-4 in T cells from peripheral blood of patients with systemic lupus erythematosus and its clinical significance

Objective: To investigate CTLA-4 expression in T cells from peripheral blood of patients with systemic lupus erythematosus(SLE) and its significance in clinic. Methods: Peripheral blood mononuclear cells (PBMCs) from SLE patients and healthy donors were isolated and then cultured with anti-CD3 and anti-CD28 antibodies for 48 hours. Before and after culture, the cells were detected for the percentages of CTLA-4+ cells in CD4 and CD8 T subsets by flow cytometer (FCM). Based on these data, the correlation between CTLA-4 expression in CD4 or CD8 T subsets of SLE patients and SLE disease activity index(SLEDAI) and kidney damage were analyzed. The cell culture supernatants were also collected for the determination of free CTLA-4 level by ELISA. Results: In fresh PBMC, CTLA-4+ cell percentages of CD4+CD25+ and CD8+CD25+T subsets, in SLE patients, were significantly higher than those in controls, and were positively correlated with SLEDAI; CTLA-4+ cell percentage of CD8+CD28- T subset was also significantly higher in SLE than that in controls, but was not correlated with SLEDAI. After stimulation with anti-CD3 and anti-CD28, in the cultured cells, CTLA-4+ percentages of CD4+CD25+, CD8+CD25+ and CD8+CD28- T subsets were significantly lower in SLE than those in controls, but was not correlated with SLEDAI, while in active SLE, CTLA-4+ cell percentage of CD8+CD28- T subsets was significantly lower in patients with kidney damage than that in patients without kidney damage; CTLA-4 level of the culture supernatant was lower in SLE patients than that in controls. Conclusions: The abnormally increased expression of CTLA-4, in T(CD4+ and CD8+) cells fresh isolated from SLE patients T cells might indicate disease development with T cell activation. On the other hand, T cells of SLE patients are deficient in induced expression of CTLA-4,which might be related with the deficient ability of reactivation of SLE T cells in vitro.