重症肌无力小鼠模型的建立

目的建立重症肌无力小鼠模型。方法电鳗乙酰胆碱受体(TnAChR)和完全弗氏佐剂(CFA)混合物免疫C57BL/6J小鼠,经二次加强免疫后,检测肌力、腓肠肌肌电图、膈肌终板电镜、血清抗体水平等指标。结果与对照小鼠相比,发病小鼠表现出肌力减弱的症状,肌电图显示小鼠腓肠肌复合动作电位振幅幅度显著下降,电镜证实神经肌接头处突触后膜变平、皱褶减少、空泡样变性,发病小鼠血清抗体水平明显升高。结论成功建立了重症肌无力小鼠模型,有助于探讨其发病机理及探索治疗自身免疫病新的途径和方法。     

芪参地黄颗粒对实验性自身免疫性重症肌无力大鼠B细胞介导的免疫机制研究

摘要 目的：探讨芪参地黄颗粒对实验性自身免疫性重症肌无力（EAMG）大鼠B细胞介导的免疫机制。方法：通过Rα97-116肽段和完全弗氏佐剂免疫,成功将30只Lewis大鼠构建EAMG模型,将EAMG大鼠随机分为模型组、芪参地黄颗粒低、中、高剂量组和阳性药组,每组6只。进一步观察大鼠体重及临床症状,检测血清中乙酰胆碱受体抗体（AChR-Ab）含量、脾脏组织CD19和CD27的蛋白表达、B淋巴细胞刺激因子（BAFF）、B细胞趋化因子CXC配体13（CXCL13）、C-X-C趋化因子受体5型（CXCR5） mRNA表达。结果：经给药治疗后芪参地黄颗粒低、中、高剂量组和阳性药组与模型组相比体重增加（P＜0.05）,临床症状评分均下降（P＜0.05）。经给药治疗后,与模型组相比,芪参地黄颗粒低、中、高剂量组血清中AChR-Ab含量均降低（P<0.05）,芪参地黄颗粒中、高剂量组脾脏组织CD27蛋白表达、CD19蛋白表达和BAFF mRNA表达降低（P＜0.05）,芪参地黄颗粒高剂量组脾脏组织CXCL13和CXCR5 mRNA表达降低（P＜0.05）,且芪参地黄颗粒中、高剂量组脾脏组织CD19蛋白表达较阳性药组下降（P＜0.05）。结论：芪参地黄颗粒通过降低EAMG大鼠CD19和CD27蛋白、BAFF、CXCL13和CXCR5 mRNA的表达,减少B细胞的分化增殖,抑制B细胞产生AChR-Ab,减少对乙酰胆碱受体的破坏,使EAMG大鼠体重增加,临床症状得到改善。     

S100/RAGE在实验性自身免疫性重症肌无力中对T细胞的作用及其机制研究

目的:探讨RAGE及其配体S100B在实验性自身免疫性重症肌无力(EAMG)中对T细胞的作用及其相关机制。方法:选取体重160-180g的Lewis大鼠,并将其随机分为EAMG模型组和CFA对照组。EAMG模型组大鼠通过尾根部注入200μL含有R-ACh R97-116肽段的免疫乳剂,并于初始免疫后的第30天尾根部追加免疫一次;CFA对照组大鼠为免疫乳剂中不含有R-ACh R97-116肽段。采用流式细胞术检测和比较两组大鼠CD4+T细胞上RAGE的表达情况;ELISA方法检测淋巴细胞培养上清中IFN-γ、IL-4、IL-17、TGF-β、IL-6和S100B的表达水平;采用S100B体外干预淋巴细胞,进一步检测S100B对EAMG大鼠T细胞增殖、亚型分布、细胞因子分泌的影响。结果:在疾病发生的晚期时相(初次免疫后第45天),EAMG组淋巴细胞CD4+T细胞上RAGE的表达明显高于CFA组(P0.001),血清中RAGE的配体S100B的表达也高于CFA组(P0.001);体外加入S100B干预能促进T淋巴细胞的增殖,与未干预组相比较差异显著(P0.05);S100B刺激后,Th1细胞和Th17细胞的百分比进一步增高,Th2细胞和Treg细胞百分比下降(PTh10.05,PTh170.05,PTh20.05,PTreg0.05),IFN-γ和IL-17的表达上调(PIFN-γ0.05,PIL-170.05),而IL-4和TGF-β表达下降(PTGF-β0.01,PIL-40.05),Th17细胞的调控因子IL-6表达升高(PIL-60.05)。结论:RAGE及其配体S100B参与EAMG的发病过程,在晚期时相中表现出明显的致病性;RAGE与S100B相互作用可以上调T细胞的致病性作用,加重四种辅助性T细胞之间的网络失衡。     

重症肌无力的治疗

获得性重症肌无力是一种累及神经肌肉肌接头的自身免疫性疾病.突触后膜的乙酰胆碱受体受到免疫攻击而破坏,以致不能产生足够的终板电位,突触后膜传递功能障碍而产生肌无力.多数患者在病程的不同时期需要接受免疫治疗,并通过适当治疗获得完全或部分缓解.本文将就重症肌无力的胆碱酯酶抑制剂治疗、免疫调节治疗及胸腺切除手术的常规方法及进展进行综述.包括常用药物的剂量、用法、疗程、适应症、副作用以及针对副作用的临床对策.治疗的目标是使患者达到临床或药物缓解并将治疗的副作用降到最低.同时针对重症肌无力患者的治疗应根据疾病分型、严重程度、是否存在合并症而个体化,并强调患者的积极参与.近年来由于新型免疫抑制药物逐渐应用到重症肌无力的治疗中,使重症肌无力患者的临床转归明显改善,故本文重点介绍免疫抑制药物,特别是新型的免疫抑制剂,如环孢素A、霉酚酸酯、他克莫司及利妥昔单抗等,并介绍这些药物的治疗作用机制.     

Myasthenia Gravis and the Myasthenic Syndrome

Two disorders of neuromuscular transmission producing muscle weakness and easy fatigability which may confront the physician are myasthenia gravis and the myasthenic syndrome. The former has early symptoms and signs of oculobulbar and then extremity weakness with rapid decline of action potential and contractile strength with repetitive use and nerve-muscle stimulation. Anticholinesterases improve strength.The myasthenic syndrome has early symptoms and signs of pelvic girdle, pectoral girdle and proximal limb muscle weakness. This is worst when first starting to use or carry out nerve muscle stimulation in the rested muscles. It improves significantly for a time with use or on rapid stimulation, and then declines with continued activation. Deep tendon reflexes are sluggish or absent. Small cell carcinoma of the lung is often associated. Guanidine improves the strength. Other features and possible underlying mechanisms of the two disorders help to differentiate and treat them.     

Insights into the Classification of Myasthenia Gravis

Background and Purpose

Myasthenia gravis (MG) is often categorized into thymoma-associated MG, early-onset MG with onset age <50 years, and late-onset MG with onset age ≥50 years. However, the boundary age of 50 years old between early- and late-onset MG remains controversial, and each category contains further subtypes. We attempted to classify MG from a statistical perspective.

Methods

We analyzed 640 consecutive MG patients using two-step cluster analysis with clinical variables and discrimination analysis, using onset age as a variable.

Results

Two-step cluster analyses categorized MG patients into the following five subtypes: ocular MG; MG with thymic hyperplasia (THMG); generalized anti-acetylcholine receptor antibody (AChR-Ab)-negative MG; thymoma-associated MG; and generalized AChR-Ab-positive (SP) MG without thymic abnormalities. Among these 5 subtypes, THMG showed a distribution of onset age skewed toward a younger age (p<0.01), whereas ocular MG and SPMG without thymic abnormalities showed onset age skewed toward an older age (p<0.001 and p<0.0001, respectively). The other 2 subtypes showed normal distributions. THMG appeared as the main component of early-onset MG, and ocular MG and SPMG without thymic abnormalities as the main components of late-onset MG. Discrimination analyses between THMG and ocular MG and/or SPMG without thymic abnormalities demonstrated a boundary age of 45 years old.

Conclusions

From a statistical perspective, the boundary age between early- and late-onset MG is about 45 years old.     

Disorders Affecting the Acetylcholine Receptor: Myasthenia Gravis and Congenital Myasthenia

Abstract

Myasthenia gravis (MG) is an autoimmune disease in which anti-acetylcholine receptor antibodies (anti-AChR) cause loss of functional endplate AChR by increasing AChR degradation, and by complement-mediated destruction. MG anti-AChR binds to regions on the human AChR which can be defined by monoclonal antibodies (mabs).

Several congenital forms of myasthenia have been described, three of which may directly involve abnormalites of the AChR, including one in which the open-time of the ion channel is prolonged.     

血清胆红素与尿酸水平对重症肌无力的临床意义

目的：探讨血清胆红素以及尿酸的水平对重症肌无力患者的临床价值。方法：选取我院确诊的重症肌无力患者作为实验组, 另选择同期体检的健康志愿者作为对照组。检测并比较两组血清直接胆红素(DBIL)、间接胆红素(IBIL)、总胆红素(TBIL)、尿酸 (UA)及肌酐(Cr)等指标水平。结果：实验组血清DBIL、IBIL、TBIL、UA 水平均显著低于对照组,差异有统计学意义(P＜0.05),但实 验组不同类型的MG 患者血清DBIL、IBIL、TBIL、UA水平比较差异均无统计学意义(P>0.05)。同组男性DBIL、IBIL、TBIL、UA值 均明显高于女性,差异具有统计学意义(P<0.05);两组间相同性别比较,实验组DBIL、IBIL、TBIL、UA 均低于对照组,差异有统计 学意义(P＜0.05)。结论：检测血清BIL 和UA水平对诊断重症肌无力具有一定的参考价值。     

Repeated Acetylcholine Receptor Antibody-Concentrations and Association to Clinical Myasthenia Gravis Development

Introduction

We aimed to examine the longitudinal association between Myasthenia Gravis (MG) clinical severity and concentration of acetylcholine receptor (AChR)-antibodies to evaluate if AChR-antibody variations correlate to disease severity. A positive AChR-antibody test is specific for MG.

Material and Methods

All patients from western Norway who had two or more AChR- antibody tests in the period 1983–2013 were identified. The Myasthenia Gravis Foundation of America (MGFA) Clinical Classification was used to grade disease development. Multiple ordinal logistic regression analysis was used to estimate a possible predictive effect for AChR-antibody concentration on MGFA classification result.

Results

In 67 patients two or more AChR-antibody tests with a corresponding MGFA-score were performed, with a total of 309 tests. 56 patients were treated with immunosuppressive drugs and 11 by pyridostigmine only. There was a positive association between concentration of AChR-antibodies and longitudinal MGFA-score for the subgroup with immunosuppressive treatment, but not for those treated with pyridostigmine only. This association between AChR-antibody concentration and MGFA score declined with increasing time since onset (p = 0.005 for the interaction of group×time×concentration).

Conclusions

For MG patients with immunosuppressive treatment, repeated AChR-antibody measurements give information about clinical development, and can therefore be of support in therapeutic decisions.     

AMP-Deaminase from Thymus of Patients with Myasthenia Gravis

Myasthenia gravis (MG) is characterized clinically by skeletal muscle fatigue following the excessive exercise. Interestingly most of MG patients manifest parallely also some abnormalities of the thymus.AMP-deaminase (AMPD) from human thymus was not a subject of studies up to now. In this paper, mRNA expression and some physico-chemical and immunological properties of AMPD purified from the thymus of MG patients were described. Experiments performed identified the liver isozyme (AMPD2) as the main isoform of AMPD expressed in this organ. The activity of AMPD found in this organ was higher than in other human non-(skeletal) muscle tissues indicating on role the enzyme may play in supplying of guanylates required for the intensive multiplication of thymocytes.     

Isozymes of AMP-Deaminase in Muscles Myasthenia Gravis Patients

Similar symptoms observed in Myasthenia gravis (MG) can be also detected in the case of skeletal muscle AMP-deaminase deficiency. We compared the activity and expression of AMP-deaminase (AMPD) products in skeletal muscles of MG patients and MG-free individuals. The activity of AMP-deaminase in the muscles of MG patients was significantly higher than in the controls and was 2.05 µmol/min/mg protein (±0.31). The two groups differ in level of AMPD product expression. Furthermore in MG-group molecular size of isoform AMPD1 is 90 kDa in contrast to MG-free group where is present 70 kDa isoform of enzyme. The data suggests that the disturbances in transmission of neuronal signaling, taking place in the skeletal muscles of MG patients, may also change energetic metabolism of the affected muscles by changing molecular mass of isoform.     

The Role of Radiation Therapy in Myasthenia Gravis

Myasthenia gravis is a serious and debilitating disease associated with conduction defects occurring at the myoneural junction. About 15 per cent of the patients have associated tumors of the thymus and 80 per cent of the remaining patients show abnormalities of the thymus. Although a definite relationship between cause and effect has not been proved, thymectomy or radiotherapy of the thymus does seem to influence the disease.Seven cases of myasthenia gravis in which radiation therapy was used at the University of California Medical Center are reported and compared with those described in the literature. It is concluded that patients whose disease is progressing and not well managed medically, and who have no evidence of thymoma, should be treated by irradiation—whether pre-operatively or as definitive treatment, depending on the result of irradiation. Those patients with evidence of thymoma should be irradiated before surgical procedure. Small tumors, or patients in whom surgical risk is increased, may be managed by radiation therapy alone.     

重症肌无力患者免疫球蛋白治疗的最佳剂量探讨

目的:探讨重症肌无力患者采用免疫球蛋白治疗的最佳剂量。方法:选择2007年8月到2014年11月在我院收治的174例重症肌无力患者,随机分为ACS组、小剂量IgG组和大剂量IgG组,分别每日静脉滴注15 mg肾上腺素、250 mg免疫球蛋白和500 mg免疫球蛋白进行治疗,对比三组的临床疗效、住院时间和呼吸机辅助时间。结果:经过治疗后,小剂量IgG组与ACS组总有效率无显著性差异(P0.05);大剂量IgG组总有效率明显高于小剂量IgG组和ACS组,具有显著性差异(P0.05);大剂量IgG组患者的住院时间和呼吸机辅助时间均明显少于ACS组和小剂量IgG组,具有显著性差异(P0.05)。结论:500 mg免疫球蛋白静脉滴注临治疗重症肌无力,临床疗效显著,能明显缩短患者的住院时间和呼吸机辅助时间,值得在临床上推广。     

321例重症肌无力患者睡眠质量分析

目的:分析312例重症肌无力患者病情稳定期的睡眠质量。方法:收集2013年2月—2014年6月第四军医大学唐都医院神经内科门诊就诊的重症肌无力患者,应用匹兹堡睡眠质量指数(PSQI)对患者进行近1月的睡眠质量问卷调查、重症肌无力定量评分表(QMG)进行病情评分,以P0.05为有统计学意义,对MG患者睡眠质量指数、各因子分进行分析研究。结果:符合重症肌无力诊断标准、知情同意并纳入研究患者共有321例,男156,女165。研究发现,多数重症肌无力患者有睡眠质量问题:性别与睡眠质量、病情评定无相关性(P0.05);重症肌无力患者睡眠质量问题主要表现为入睡时间、睡眠效率、睡眠障碍、日间功能方面。结论:重症肌无力患者存在睡眠质量差这一问题。改善MG患者肌无力症状的同时,应注重改善患者的睡眠质量。