乙酰胆碱受体抗体阳性重症肌无力外周血单个核细胞miRNA表达谱

目的 本研究对比乙酰胆碱受体抗体阳性重症肌无力患者（AchR-MG）和正常对照组外周血单个核细胞miRNA,预测对AchR-MG发病可能产生影响的通路,为进一步探讨发病机制打下基础。方法 采用病例对照研究方法,基于高通量测序,筛选了AchR-MG特异性表达的miRNA。利用TargetScan、miRanda进行靶基因交叉预测,利用基因条目（GO）和京都基因与基因组百科全书（KEGG）进行富集分析。结果 共筛选出差异性miRNA 28种,其中上调17种,下调11种。差异最显著的前5个为：mmu-miR-3968、miR-4785、miR-210-3p、miR-664a-3p、miR-2277-5p。miR-4785预测到METTL22、TMEM38A、ZNF324、ITGB4、CDC34等395种靶基因。最终识别了319条GO term（P<0.01）,获得了119个的风险通路（P<0.05）。结论 AchR-MG特异性表达miR-4785、miR-210-3p、miR-664a-3p、miR-2277-5p等28种miRNA。以Wnt信号通路为代表的多种通路可能参与AchR-MG的发病。     

乙酰胆碱受体抗体测定对儿童重症肌无力的诊断价值

重症肌无力(MG)是累及神经肌肉接头突触后膜乙酰胆碱受体的自身免疫性疾病,免疫学研究已发现,患者血清中针对靶细胞的抗乙酰胆碱受体抗体(AchRsb)滴度增加,并认为AchRab是MG的主要致病因子。故检测患儿血清AchRab具有诊断MG的特异性价值。本文应用ELASA法对63例MG患儿进行了血清AchRab测定,发现大多数患儿抗体滴度明显升高,能反映临床情况,具有很高的实验诊断价值。     

重症肌无力发病的非乙酰胆碱受体抗体机制

重症肌无力 (ＭＧ)是一种主要由乙酰胆碱受体 (ＡＣｈＲ)抗体介导的自身免疫性疾病。然而 ,约有 1 5 %的ＭＧ患者血清中未检测到ＡＣｈＲ抗体 ,这些患者被称为抗体阴性重症肌无力 (ｓｅｒｏｎｅｇａｔｉｖｅＭＧ ,ＳＮＭＧ) [1 ] 。由于ＳＮＭＧ患者的临床表现与抗体阳性的ＭＧ患者基本相似 ,对免疫抑制剂治疗亦敏感 ,而且给小鼠注射ＳＮＭＧ患者的血清或ＩｇＧ亦能复制出ＭＧ模型[2 ] ,因此 ,对ＭＧ发病机制而言 ,除ＡＣｈＲ抗体的介导外 ,可能还有其他的抗体或分子参与。近年来对ＭＧ发病的非ＡＣｈＲ抗体机制研究取得了一系列的进展 ,综…     

重症肌无力血清乙酰胆碱受体抗体的阳性率及其影响因素

采用ABC-ELISA法检测162例重症肌无力患者的224份血清标本,100例正常人和78例其他疾病病人的血清中AchRab。重症肌无力病人的抗体阳性率为80.2％,其中单纯眼肌型63.1％,脊髓肌型90.0％,延髓肌型93.8％和全身肌型91.5％。合并胸腺瘤的阳性率为83.3％,与全组阳性率无显著性差异。激素和血浆交换治疗均未影响抗体阳性结果。随访观察表明,重症肌无力病人的AchRab阳性率与疾病严重程度不成线性相关。我们认为,AchRab滴度虽然与临床状况不相关,但在重症肌无力的诊断和自身免疫病因的研究中,仍是一项重要参数。     

重症肌无力患者外周血单个核细胞白细胞介素6活性变化

探讨白细胞介素 6(IL -6)在重症肌无力 (MG)发病机理中的作用及其临床意义。　　方法　采用3H -TdR掺入法检测 40例正常对照及 42例MG患者外周血单个核细胞IL -6分泌活性。　　结果　MG患者组IL -6活性显著高于正常对照组 ,且IL -6活性变化与乙酰胆碱受体抗体产生以及与MG临床类型、病情、预后密切相关。　　结论　IL -6在MG发病机理中起着重要作用 ,检测IL -6活性对区分MG临床类型、判断病情、推测预后、指导治疗有重要的参考价值。     

重症肌无力乙酰胆碱受体亚基基因结构研究进展

重症肌无力发病机制尚不清楚,但与乙酰胆碱受体密切相关。随着分子生物学技术的发展,AChR的α、β、γ、δ及ε亚基的cDNA序列已经确定;不同亚基基因突变或使AChR合成减少,或影响AChR对ACh的反应,或使AChR功能障碍。本文从遗传学角度对重症肌无力乙酰胆碱受体各亚基及其基因的研究近况进行综述。     

重症肌无力的临床分型、电诊断及乙酰胆碱受体抗体的比较

本文对３９８例重症肌无力（ＭＧ）患者的临床分型、重复电刺激（ＲＮＳ）及血中乙酰胆碱受体抗体（ＡｃｈＲ·Ａｂ）浓度三者作了比较分析。其中眼肌型２２４例，全身型１６１例，肌无力危象１３例。ＲＮＳ总的阳性率５１．３％，其中刺激腋神经时最高（６８．４％）。全身型者ＲＮＳ阳性率明显高于眼肌型。对临床眼肌型，ＲＮＳ可能发现亚临床病变，有助于预后的估计。ＲＮＳ异常与ＡｃｈＲ·Ａｂ浓度升高有相关性（Ｐ＜０．０５），对于ＭＧ的诊断，两者的结果具有互补性，其中ＲＮＳ异常而ＡｃｈＲ·Ａｂ正常者占２１．５％，相反的情况占２０．５％。     

乙酰胆碱受体抗体与全身型重症肌无力手术预后的关系

目的比较乙酰胆碱受体抗体(ACh R-Ab)阳性全身型重症肌无力(MG)与ACh R-Ab阴性全身型MG患者胸腺切除术的疗效。方法将124例于胸外科接受胸腔镜胸腺扩大切除术的全身型MG患者,根据术前血清ACh R-Ab表现,分为ACh R-Ab阳性组(81例)和ACh R-Ab阴性组(43例),比较两组患者的完全稳定缓解率。结果两组患者的性别、手术时年龄、术前病程、首发症状及胸腺病理类型等基本情况组间比较差异无显著性。术后ACh R-Ab阳性组失访1例,阴性组失访2例,共完成随访121例患者,随访时间15~84个月,其中ACh R-Ab阳性组80例,随访(44.9±19.9)个月,ACh R-Ab阴性组41例,随访(48.2±20.3)个月。术后完全稳定缓解率ACh R-Ab阳性组(48.8%)显著高于ACh R-Ab阴性组(26.8%),χ2=5.372,P=0.020。术后总有效率ACh R-Ab阳性组为95.0%,ACh R-Ab阴性组为90.2%,两组比较差异无统计学意义(χ2=0.993,P=0.319)。完全稳定缓解率的Kaplan-Meier生存曲线提示,随着术后随访时间的延长,完全稳定缓解率逐渐升高;Log-rank法比较两组之间的完全稳定缓解率均逐渐升高(P=0.03)。结论血清ACh R-Ab阳性患者胸腺扩大切除术后完全稳定缓解率优于ACh R-Ab阴性患者,随着随访时间的延长,完全稳定缓解率逐渐升高,但两组患者的总有效率类似。     

重症肌无力患者烟碱型乙酰胆碱受体抗体致鼠脑干？…

目的神经肌接头（ＮＭＪ）处乙酰胆碱（ＡＣｈ）传递障碍，是重症肌无力（ＭＧ）发病机制，然而，近年有研究表明部分ＭＧ患者有中枢神经系统（ＣＮＳ）受损的症状和神经电生理方面的异常表现，本研究为探讨其机制。方法 从烟碱型乙酰胆碱受体抗体（ｎＡＣｈＲ－ａｂ）阳性的全身型ＭＧ患者血清中提取ＩｇＧ将其注入ＳＤ大鼠脑室系统，观察其对脑干听觉诱发电位（ＢＡＥＰ）的影响。结果 ｎＡＣｈＲ－ａｂ使脑干听觉传导功能异常，     

重症肌无力患者HLA-DQB1等位基因与乙酰胆碱受体抗体的相关性研究

目的探讨重症肌无力(MG)患者HLA-DQB1等位基因和乙酰胆碱受体抗体(AchRab)的相关性.方法采用ELISA法对50例MG患者以及48名健康对照者进行AchRab检测,对其中36例患者同时进行了HLA-DQB1检测.结果眼肌型患者AchRab阳性频率显著低于全身型,18岁以下组AchRab显著低于30岁以上组;本组所有DQB1等位基因和AchRab相关性分析结果均P>0.05.结论 MG患者发病年龄和AchRab相关,HLA-DQB1等位基因和AchRab无关,AchRab受其他遗传因素影响.     

Acetylcholine receptor antibody in myasthenia gravis

Radioimmunoassay techniques were used to detect antibodies to the acetylcholine receptor (AAChR) in 164 patients with adult-onset myasthenia gravis. AAChR levels above 0.6 nM/l were considered pathological and were found in 67% of the patients with an average value of 58.99 +/- 125.02 nM/l (0.6-900.0). Correlation, with clinical functional status, the histopathological thymus alterations and the different therapeutics used did not disclose any statistically significant differences.     

The B-cell repertoire in myasthenia gravis includes all four acetylcholine receptor subunits

By enumerating cells secreting IgG antibodies of particular specificities using an enzyme-linked immunospot (ELISPOT) assay, the B-cell responses to Torpedo acetylcholine receptor (AChR) and its α-, β-, γ- and δ-subunits in peripheral blood from patients with myasthenia gravis (MG), and controls with other neurological diseases (OND) as well as healthy subjects were determined. Compared to controls, the patients with MG had elevated numbers of B cells secreting antibodies against AChR and its α-, β-, γ- and δ-subunits in peripheral blood in parallel. The mean numbers of anti-AChR antibody secreting cells were about 17 per 10⁵ blood MNC, and for the subunits 10 to 15 in MG patients, compared to between 0.8 and 1.9 per 10⁵ blood MNC in OND patients, and 0.1 to 0.3 in healthy controls. Such B cells detected in controls probably represent naturally occurring B cells responded to AChR and its subunits. The finding that most (60%) MG patients had B cells predominantly recognizing the α-subunit may be an indirect argument for the existence of a main immunogenic region (MIR). In the remaining 40% of patients with MG the predominant B-cell responses were directed to β-, γ- or δ-subunit. The data suggest that all four AChR subunits may function as strong immunogens in MG, though the α-subunit may be the major immune target in a substantial proportion of MG patients.     

Inhibition of peripheral blood natural killer cell cytotoxicity in patients with myasthenia gravis treated with plasmapheresis

Background and purpose: Myasthenia gravis (MG) is an autoimmune disorder that may involve natural killer (NK) cells. Although NK cells are part of the innate immune system, they also influence adaptive immune responses. Double‐filtration plasmapheresis (DFP) is an effective therapy for MG crisis. Thus, we examined the effects of DFP on the cytotoxicity of NK cells. Methods: A total of 20 patients with MG and 16 healthy controls were recruited for the study. Ficoll‐Paque‐isolated peripheral blood mononuclear cells (PBMCs) and K562 cells were used as the effector and target cells, respectively. NK cell cytotoxicity was analyzed using flow cytometry immediately before and after DFP and upon course completion. Results: Double‐filtration plasmapheresis treatment decreased significantly the NK cell cytotoxicity in patients with MG, especially in good responders, those who were positive for acetylcholine receptor (AChR) antibodies, and those receiving immunosuppressants. Conclusions: The decrease in NK cell cytotoxicity after DFP and the decline of AChR antibody titer were observed in good responders indicating that this could benefit patients with MG.     

放射免疫法定量检测乙酰胆碱受体抗体与重症肌无力患者临床特征的相关性

目的探讨乙酰胆碱受体抗体(AChR-Ab)与重症肌无力(MG)临床特征的相关性。方法采用放射免疫法检测115例MG患者及92例对照组(非MG神经系统疾病患者42例,健康体检者50名)血清AChRAb浓度,应用临床绝对评分记录MG患者病情严重程度。分析各组血清AChR-Ab浓度的差异,以及AChR-Ab浓度与MG患者临床特征的相关性。采用ROC工作特征曲线探讨AChR-Ab诊断MG的敏感度和特异度。结果MG患者血清AChR-Ab浓度中位数(四分位数间距,下同)为3.45(39.38)nmol/L,较非MG神经系统疾病患者[0(0)nmol/L]和健康体检者[0(0)nmol/L]增高(P0.01)。全身型MG(GMG)患者AChR-Ab浓度[25.45(46.14)nmol/L]较眼肌型MG(OMG)患者[0.58(3.56)nmol/L]增高(P0.01)。用ROC曲线法分析显示,以血清AChR-Ab浓度≥0.50nmol/L作为诊断MG界值时灵敏度为72.17%,特异度为100%,曲线下面积(AUC)=0.895(95%CI:0.849~0.941)。AChR-Ab浓度与发病年龄、病程及改良Osserman分型呈正相关(r=0.220,P0.05;r=0.184,P0.05;r=0.382,P0.01),但相关性较弱(均r0.5),与临床绝对记分无相关性(r=0.147,P0.05)。结论用放射免疫法检测血清AChR-Ab浓度诊断MG的灵敏度和特异度均高,有助于减少MG的漏诊率及误诊率,值得临床推广。     

重症肌无力病人乙酰胆碱受体抗体的测定及临床意义

用ＥＬＩＳＡ（固相酶联免疫吸附）法测定１７２例ＭＧ病人血清乙酰胆碱受体抗体（ＡｃｈＲａｂ），结果显著高于健康献血员组和非ＭＧ病人组。不同性别、病程及临床类型与ＡｃｈＲａｂ无相关性，但４１～５０岁组的显著高于其他年龄组。６７例类固醇激素治疗组、２２例大剂量两种球蛋白治疗组、１２例胸腺切除术组及３例ＭＧ危象病人２４次血浆交换疗法（ＰＥ）组，治疗后伴随肌无力症状的好转，ＡｃｈＲａｂ均显著低于治疗前。结果表明：ＡｃｈＲａｂ测定为ＭＧ诊断提供了可靠的实验依据，为类固醇激素、大剂量丙种球蛋白、胸腺切除术和ＰＥ等治疗ＭＧ提供理论依据和疗效评定的实验指标，进一步证实了ＭＧ免疫学发病机理。     

Correlation of C3 level with severity of generalized myasthenia gravis

Acute exacerbation of generalized myasthenia gravis (GMG) can cause swallowing impairment, respiratory failure, or death. It is important to identify immunological factors that might be regarded reliably as an index of the patient's clinical condition, response to treatment, and measure of certain immune aberrations of MG. In this study we investigated correlations between complement component C3, acetylcholine receptor antibody (AChRab) titer, and clinical severity of GMG. AChRab titer and C3 concentration were determined by radioimmunoassay and nephelometry, respectively. The clinical severity of GMG was assessed by the quantitative MG score (QMGS) according to Besinger and colleagues. Our findings indicate that the C3 level correlates with clinical severity of AChRab‐positive GMG. Muscle Nerve, 2009     

Muscle antibodies in the cerebrospinal fluid from patients with myasthenia gravis

IgG antibodies to nicotinic acetylcholine receptor (AChR) and to a muscle antigen extracted by citric acid, were quantified in serum and cerebrospinal fluid (CSF) from 28 patients with myasthenia gravis, and the serum:CSF ratios compared with those of total IgG. Agarose-electrophoresis and calculations of the IgG index and Tourtellotte's formula were performed. No evidence of intrathecal antibody synthesis was demonstrated. Compared to the total IgG concentrations in serum and CSF, the CSF concentrations of IgG AChR antibodies were lower than expected.