系统性红斑狼疮患者外周血中γδT细胞的变化及临床意义

Change and clinical significance of peripheral blood γδT cells in patients with systemic lupus erythematosus

目的探讨γδT细胞在系统性红斑狼疮（SLE）患者外周血中的变化及临床意义。方法流式细胞术检测42例SLE患者、20名健康对照组外周血中CD3＋γδ8＋T细胞百分率及绝对数；用膜联蛋白-V/碘化丙啶法检测6例活动期SLE患者及6名正常对照组外周血中CD3＋T细胞及γδ＋T细胞的凋亡率。酶联免疫吸附试验（ELISA）法测定42例SLE患者血清抗核抗体和抗双链DNA（dsDNA）抗体水平。统计学方法采用t检验及Pearson相关分析。结果活动期SLE患者外周血中T细胞百分率[（3．0±1．8）％]较非活动期[（5．3±3．0）％]及健康对照组[（6．8±2．8）％]均显著下降（t值分别为-3．071和-5．913，P均〈0．01）；活动期SLE患者78T细胞绝对数[（1．7±1．6）×10^7／L]明显低于非活动期[（5．3±3．6）×10^7／L]（t=-3．292，P〈0．01），且两者均低于健康对照组[（10．1±5．0）×10^7／L]（t值分别为-7．247和-2．905，P均〈0．01）。活动期SLE患者78T细胞绝对数与SLE疾病活动指数（SLEDAI）评分呈负相关（r=-0．365，P=0．047）。SLE患者外周血中78T细胞百分率（r=-0．336，P=0．030）及绝对数（r=-0．410，P=0．007）均与红细胞沉降率（ESR）呈负相关，γδT细胞绝对数与血红蛋白呈正相关（r=0．409，P=-0．007）。此外，SLE患者外周血中γδT细胞凋亡率显著高于健康对照组及SLE患者CD3＋T细胞凋亡率（t值分别为2．886和2．952，P均〈0．05）。结论SLE患者外周血中γδT细胞数量下降，与病情活动相关；γδT细胞数量下降的机制可能与凋亡增加有关。

Objective To investigate the number of γδT cells in the peripheral blood from patients with systemic lupus erythematosus （SLE） and their correlation to disease activity. Methods γδT ceUs were detected in the peripheral blood from 42 SLE patients and 20 normal controls by flow cytometry. Anniex-V/PI double-staining flow cytometry was employed to observe the proportion of the apoptotic γδ and CD3＋T cells in 6 SLE patients with active disease and 6 normal controls, respectively. The levels of plasma anti-nuclear antibody and anti-dsDNA antibody were determined by using enzyme-linked immunosorbent assay. Data were analyzed with t test and Pearson＇s correlation test. Results The percentages of γδT cells were remarkably down-regulated in SLE patients [（3.0±1.8）% ] with active disease compared with that of those patients with inactive [（5.3±3.0）%] disease and normal controls [（6.8±2.8）%]（t=-3.071 and -5.913 respectively, both P〈0.01 ）. The absolute number of γδT cells decreased significantly in SLE patients with active disease [ （ 1.7±1.6）×10^7/L] than those with inactive SLE [ （5.3±3.6）×10^7/L] （t=-3.292, P〈0.01）, and both were lower than the normal controls [ （10.1±5.0）×10^7/L]（t=-7.247 and -2.905 respectively, both P〈0.01）. There was a negative correlation between systemic lupus erythematosus disease activity index （SLEDAI） and T cell counts in 30 SLE patients with active disease （r=-0.365, P=0.047）. 78T cell percentage （r=-0.336, P=0.030） and counts （r=-0.410, P=0.007） were both inversely correlated with the erythrocyte sedimentation rate, but positive correlation were found between hemoglobulin and γδT cell counts （r=0.409, P=0.007）. The apoptosis of γδT cells in SLE patients was more common than in normal controls （t=2.886, P〈0.05）. The number of apoptotic γδT cells was higher than that of CD3＋T cells in SLE patients （t=2.952, P〈0.05）. Conclusion γδT cells of the peripheral blood of SLE patients are down-regulated partially due to excessive apoptosis, which may correlate with the disease activity.