Abstract:

Objective To investigate the expression of helper T cell 17 (Th17) cells and associated cytokines in patients with myasthenia gravis (MG) and its correlations to the level of anti-acetylcholine receptor (AChR) antibodies. Methods Thirty patients with MG including 16 patients with ocular myasthenia gravis (OMG) and 14 patients with general myasthenia gravis (GMG) were enrolled in the study from September 2016 to December 2017. Flow cytometry was used to calculate the percentage of circulating Th17 cells in the peripheral blood mononuclear cell (PBMC). Real-time reverse transcription polymerase chain reaction (RT-PCR) was used to examine the expression of interleukin-17A (IL-17A) retinoid-related orphan receptor γ (RORγ) mRNA. Enzyme-linked immunosorbent assay (ELISA) was used to detect IL-17A, IL-6, IL-23 and anti-AChR antibodies. Results The percentage of circulating Th17 cells (t = - 3.312, P = 0.002; t = - 2.286, P = 0.030), the expression of the IL-17A level (t = - 4.282, P = 0.004; t = - 2.788, P = 0.007) and RORγ mRNA (t = 4.408, P = 0.001; t = 1.991, P = 0.049) in GMG and OMG group were higher than those in control group with statistical significance. IL-23 was also higher in the GMG group than that in the control group (t = -2.267, P = 0.031). The percentage of Th17 and level of IL-17A were positively correlated with the anti-AChR antibodies (r = 0.851, P = 0.012; r = 0.743, P = 0.025; respectively). Conclusions The high level of Th17 cells and IL-17A may be closely related to the etiology of MG. It must be verified in the future.

Key words: Myasthenia gravis, T-lymphocytes, Interleukins, Reverse transcriptase polymerase chain reaction, Enzyme-linked immunosorbent assay

摘要：

目的 研究重症肌无力患者外周血辅助性 T 细胞 17（Th17)及其相关细胞因子水平，探讨其与血清抗乙酰胆碱受体（AChR）抗体水平的相关性。方法 纳入 2016 年 9 月至 2017 年 12 月共 30 例初诊重症肌无力患者，眼肌型（OMG）16 例、全身型（GMG）14 例。流式细胞术检测外周血单个核细胞Th17细胞比例，实时定量聚合酶链反应检测 Th17 细胞标志性细胞因子白细胞介素-17A（IL-17A）及其相关转录因子维 A 酸相关孤儿受体γ（RORγ）mRNA 水平，酶联免疫吸附试验检测血浆 IL-17A、IL-6、IL-23和抗 AChR 抗体水平。结果 与正常对照组相比，GMG 组和 OMG 组外周血 Th17 细胞比例（t = - 3.312，P = 0.002；t = - 2.286，P = 0.030）及其相关转录因子 RORγ mRNA 表达水平（t = 4.408，P = 0.001；t = 1.991， P = 0.049），以及IL-17A 水平（t = - 4.282，P = 0.004；t = - 2.788，P = 0.007）均高于正常对照组；GMG 组IL-23水平亦高于正常对照组（t = - 2.267，P = 0.031）。重症肌无力患者外周血 Th17 细胞比例及血浆 IL-17A 水平与血清抗 AChR 抗体水平呈正相关（r = 0.851，P = 0.012；r = 0.743，P = 0.025）。结论 重症肌无力患者外周血 Th17细胞数目增加、血浆IL-17A 表达水平升高，可能是导致重症肌无力发生与发展的重要原因，二者之间关系尚待进一步研究加以证实。

关键词: 重症肌无力, T 淋巴细胞, 白细胞介素类, 逆转录聚合酶链反应, 酶联免疫吸附测定