T辅助细胞17在结节病发病中的作用

摘要

目的 研究Th17在活动期结节病患者外周血和BALF中的表达特征及其特异性核转录因子mRNA水平在糖皮质激素治疗前后的变化,探讨Th17细胞在结节病免疫病理机制中的作用.方法 选择2010年7-9月在北京协和医院呼吸内科门诊经病理确诊、根据结节病诊疗建议的原则需要接受系统性糖皮质激素治疗、用药4～6周后治疗有效的活动期肺结节病患者10例(男1例,女9例)为研究组,招募性别、年龄匹配的10名健康志愿者为对照组；年龄为40 ～ 60岁,平均(52 ±8)岁.以CD4+ IL-17A+标记Th17细胞,通过流式细胞分析比较研究组治疗前和对照组外周血中Th17细胞的水平,以及研究组治疗前外周血和BALF中Th17细胞的水平.通过实时PCR的方法比较研究组治疗前后外周血中Th17细胞特异性核转录因子视黄酸相关孤独受体γt(RORγt)mRNA的表达水平.结果 (1)流式细胞分析结果:研究组治疗前外周血中 Th17细胞的比例为(1.61±1.09)％,高于对照组外周血的(0.51±0.43)％(t=3.02,P=0.014),低于同一患者BALF中的(3.05±1.87)％(t=-2.94,P=0.001).(2)实时PCR检测结果:研究组治疗前外周血中的RORγt的mRNA表达水平为(0.952±0.367),治疗后其表达水平为(0.168±0.272),RORγt mRNA表达水平有下凋趋势,但差异无统计学意义(t=1.76,P=0.057).结论 Th 17细胞可能参与结节病的发病,且可能参与糖皮质激素的治疗反应过程；抑制驱使Th17转化的细胞因子有可能成为结节病的治疗靶点.%Objective To describe the characteristic of Th17 cells in peripheral blood (PB) and bronchoalveolar lavage fluid (BALF) from patients with sarcoidosis,and to investigate the effect of glucocorticoid therapy on the expression of RORγt mRNA,and therefore to explore the role of Th17 cells in the immunopathogenesis of pulmonary sarcoidosis.Methods Ten patients with active pulmonary sarcoidosis who were prescribed with prednisone according to the guidelines were defined as the study group.All of them had positive pathological results and had definite response to corticosteroids. Ten healthy controls were recruited from volunteers with similar sex distribution and age. The proportion of CD4+ IL-17A + T cells in peripheral blood mononuclear cells (PBMC) and BALF were calculated by flow cytometry. The mRNA expression of RORc in PBMC was measured by Real-time PCR.Results The mean age was (52 ± 8) years in both the study group and the controls,and there were 9 females and 1 male in both groups.The proportion of CD4+ IL-17A + T cells was higher in the PB of sarcoidosis patients compared to that of the controls [(1.61±1.09)％ vs (0.51 ±0.43)％,t=3.02,P=0.014].For the same patients,the proportion of CD4+ IL-17A +T cells was higher in the BALF compared to that in the PB [ (3.05 ± 1.87)％ vs (1.61 ±1.09 )％,t =2.94,P =0.001 ].After 4 to 6 week therapy with glucocorticoids,all the 10 patients showed definite response. The level of RORc mRNA in the PB did not decrease significantly after treatment [ (0.952 ±0.367) vs (0.168 ±0.272),t =1.76,P =0.057],although a trend was noted.Conclusions Th17 cells was probably involved in the immunopathogenesis of sarcoidosis, and glucocorticoids might modulate the disturbance of Th17 cells in pulmonary sarcoidosis.