重症肌无力患者外周血淋巴细胞亚群水平及其临床意义

Levels of lymphocyte subsets in peripheral blood and their clinical significance in patients with myasthenia gravis

目的探讨重症肌无力(MG)患者外周血淋巴细胞亚群水平及其临床意义。方法选取MG患者90例,按受累肌群分为眼肌组(n=40)和全身组(n=50),同时选取40例健康体检者作为对照组,MG患者于免疫治疗前采集空腹静脉血5~10 mL,对照组受试者于健康体检日抽取空腹静脉血5~10 mL,2组标本均取3~5 mL分离血清,剩余样本加乙二胺四乙酸(EDTA)抗凝;采用流式细胞法检测3组受试者外周血淋巴细胞亚群CD4^(+)、CD8^(+)、CD4^(+)/CD8^(+)及NK细胞比例,采用酶联免疫吸附(ELISA)法检测2组MG患者血清抗乙酰胆碱受体抗体(AChR-Ab)的水平;采用重症肌无力定量评分(QMG)及重症肌无力绝对和相对评分(ARS-MG)评价2组MG患者首次就诊时的病情严重程度,采用Pearson和Spearman法分析MG患者外周血淋巴细胞亚群与病情严重程度及AChR-Ab的关系。结果全身组MG患者外周血CD4^(+)、CD4^(+)/CD8^(+)及NK细胞比例高于对照组和眼肌组(P<0.05)、但CD8^(+)细胞比例低于对照组和眼肌组(P<0.05),眼肌组MG患者外周血CD4^(+)/CD8^(+)和NK细胞比例高于对照组(P<0.05);全身组MG者QMG评分和ARS-MG评分均高于眼肌组(P<0.05);MG患者外周血CD4^(+)、CD4^(+)/CD8^(+)、NK细胞比例分别与QMG评分、ARS-MG评分、血清AChR-Ab阳性率呈正相关(P<0.05),但CD8^(+)细胞比例与QMG、ARS-MG评分、血清AChR-Ab阳性率呈负相关(P<0.05)。结论MG患者外周血淋巴细胞亚群水平在不同的临床分型之间存在差异,与疾病严重程度、AChR-Ab阳性率存在相关,检测淋巴细胞亚群水平可作为评价MG病情严重程度的参考指标。

Objective To investigate the level of peripheral blood lymphocyte subsets in patients with myasthenia gravis(MG)and its clinical significance.Methods Ninety patients with MG were selected and divided into ocular muscle group(n=40)and systemic group(n=50)according to the affected muscle groups.At the same time,40 healthy subjects were selected as the control group.Five to ten mililiters of fasting vein blood were collected from MG patients before immunotherapy and from control group on the day of healthy physical examination,and divided into two parts:3~5 ml blood was used to isolate serum,and the remaining part was added with ethylene diaminetetraacetic acid(EDTA)for anticoagulation,then for detecting CD4^(+),CD8^(+),CD4^(+)/CD8^(+),and NK cells using flow cytometry.Enzyme linked immunosorbent assay(ELISA)was used to detect the serum acetylcholine receptor antibody(AChR-Ab)levels in MG patients.MG Quantitative Score(QMG),MG Absolute and Relative Score(ARS-MG)were used to evaluate the severity of the condition of MG patients at the first visit.Pearson and Spearman were used to analyze the correlation of peripheral blood lymphocyte subsets with MG patients severity and the AChR-Ab levels.Results The levels of CD4^(+)and NK cells and the ratio of CD4^(+)to CD8^(+)cells in systemic group were higher than both those in control and ocular muscle groups(P<0.05),but CD8^(+)cell level was lowest in systemic groups(P<0.05).The ratio of CD4^(+)/CD8^(+)and NK cell level in ocular muscle group was higher than that in control group(P<0.05).QMG score and ARS-MG score of MG in systemic group were greater than those in ocular muscle group(P<0.05).The levels of CD4^(+)and NK cells and the ratio of CD4^(+)to CD8^(+)were positively correlated with QMG score,ARS-MG score and positive rate of serum AChR-Ab(P<0.05),in contrast,CD8^(+)cell level was negatively correlated with QMG,ARS-MG score,and positive rate of serum AChR-Ab(P<0.05).Conclusion The levels of lymphocyte subsets in peripheral blood of MG patients are different in different clinical types,and related to MG severity and the positive rate of AChR-Ab.The level of lymphocyte subsets can be used as reference indexes for evaluating MG severity.