成人特发性膜性肾病患者外周血中调节性T细胞和辅助性T细胞17的比例变化研究

Study on the proportional change of regulatory T cell/T helper cell 17 in idiopathic membranous nephropathy patients

目的研究特发性膜性肾病(IMN)患者外周血和肾组织中调节性T细胞(Treg)和辅助性T细胞17(Th17)的比例变化,探讨Treg和Th17比例失衡参与IMN发病的可能机制。方法选取于上海交通大学医学院附属新华医院就诊经肾活检确诊为IMN的患者(IMN组,n=30)、健康志愿者(健康对照组,n=20)及行肾癌手术者(肾癌对照组,n=10)为研究对象。采用流式细胞仪测定IMN组和健康对照组外周血单核细胞(PBMC)中Treg和Th17的表达;实时聚合酶链反应(PCR)法检测PBMC中叉状头/翅膀状螺旋转录因子3(Foxp3)和维甲酸相关孤核受体(RORγt)的表达水平;采用免疫组化法检测IMN组和肾癌对照组肾组织中IL-17的表达。结果流式细胞仪检测结果显示,与健康对照组相比,IMN组PBMC中CD4^+Foxp3^+Treg表达水平降低(P<0.05),Th17表达水平升高(P<0.05),Treg/Th17比值显著降低(P<0.01)。PCR检测结果显示,与健康对照组相比,IMN组PBMC中Foxp3 mRNA的表达水平明显下调(P<0.01),RORγt mRNA水平明显上调(P<0.01)。免疫组化结果显示,IMN组患者肾组织中IL-17的表达较肾癌对照组患者显著升高(P<0.05),主要体现于肾小管处。相关性分析显示,IMN组患者外周血Treg/Th17比值与24 h尿蛋白定量水平呈明显负相关(r=-0.537,P<0.05),与血清白蛋白水平呈明显正相关(r=0.669,P<0.05)。结论 IMN患者外周血中存在Treg表达水平降低和Th17表达水平升高的比例失衡,而Treg/Th17比例失衡与IMN的发病机制有关。

Objective To observe the changes of regulatory T cell(Treg) and T helper cell 17(Th17) in patients with idiopathic membranous nephropathy(IMN), and to explore the significance of Treg/Th17 imbalance in IMN pathogenesis. Methods Adults with IMN initially diagnosed by renal biopsy were selected in Shanghai Xinhua Hospital(IMN group, n=30), healthy volunteers(healthy control group, n=20) and patients with renal carcinoma(renal carcinoma control group, n=10) were selected. Flow cytometry was employed to determine the percentage of Treg and Th17 in peripheral blood mononuclear cell(PBMC) of the IMN group and the healthy control group. The expression of the transcription factors forkhead box P3(Foxp3) and retinoid-related orphan nuclear receptor γt(RORγt) of the IMN group and the healthy control group were detected by real-time polymerase chain reaction(PCR). Renal expression of IL-17 of the IMN group andrenal carcinoma control group were detected by immunohistochemistry. Results Compared with healthy control group, IMN group had decreased frequency of CD4^+Foxp3^+Treg(P<0.05), and increased frequency of Th17(P<0.05), and decreased ratio of Treg/Th17(P<0.01) in PBMC. The expression of Foxp3 mRNA in PBMC in IMN group was significantly lower than that in healthy control group(P<0.01), while the expression of RORγt mRNA was significantly higher than that in healthy control group(P<0.01). Renal expression of IL-17 in IMN group was increased significantly compared with that in renal carcinoma control group(P<0.05), mainly expressed on reanl tubular. Correlation analysis revealed that the frequency of Treg/Th17 in PBMC was correlated with 24 h protein urea(r=-0.537, P<0.05) and serum albumin(r=0.669, P<0.05). Conclusions IMN patients have the decreased expression of Treg and its transcription factor Foxp3, and the increased expression of Th17 and its transcription factor RORγt, which suggests the Treg/Th17 imbalance might be involved with IMN pathogenesis.