肢带型肌营养不良2B型与多发性肌炎的临床及病理鉴别诊断

Objective To diagnose and differentially diagnose limb-girdle muscular dystrophy type 2B(LGMD2B)and polymyositis (PM) based on clinical and pathological characteristics. Methods Muscle biopsics were obtained from 8 patients suspected with LGMD2B who were initially diagnosed with PM.The clinical and pathological data from 8 cases of LGMD2B and 4 cases of PM by using histo-and immunohistochemistry with anti-dysferlin,dystrophins,sarcoglycans,MHC-Ⅰ,CD8 monoclonal antibodies were compared.Results (1) LGMD2B and PM shared similar pathological presentations including muscle fibet degeneration and necrosis in various degree,proliferation of connective tissue,and inflammatory cell infiltration.Normal stains of dystrophins and sarcoglycans were observed.whereas absent or very faint staining of dysfedin observed in muscle biopsies of 8 patients confirmed the diagnosis of LGMD2B.while normal stains of dysferlin on sarcolemma were observed in the 4 cases of PM.MHC-Ⅰ was weakly expressed or absent in LGMD2B.while strongly expressed on sarcolemma in PM and the infiltration area of inflammation cells.The expression of CD8 on a few inflammatory cells were positive in LGMD2B.while some inflammatory cells were positive in PM.(2)Both LGMD2B and PM shared similar presentation,including proximal muscle weakness,remarkable elevation of CK,myopathic changes in electromyography.Patients with LGMD2B did not complain of apparent muscle pain.and their erythrocyte sedimentation rate and Creactive protein were in normal range.which could be used as marker to differentiate from patients with PM.Conclusions Clinically and pathologically LGMD2B and PM are presented similarly and likely to be misdiagnosed.The absence of dysferlin in LGMD2B and high expression of MHC-Ⅰ and CD8 in PM are the key index of the diagnosis and differential diagnosis between LGMD2B and PM.     

应用免疫印迹法诊断肢带型肌营养不良2A型

目的 应用免疫印迹法(Western blot)诊断肢带型肌营养不良2A型(LGMD2A)患者并与LGMD2B型相鉴别.方法 收集我院诊治的4例LGMD2型患者的临床、病理及生化检验资料.取肌肉活体组织行组织化学和免疫组织化学染色,用Western blot分析dysferlin蛋白及calpain-3蛋白的表达.结果 LGMD2A与2B型患者的临床症状相似;免疫组织化学染色显示所有患者均出现不同程度的dysferlin缺失.但Western blot揭示:LGMD2A型患者calpain-3蛋白完全缺失,dysferlin蛋白部分缺失;而2B型患者则相反.结论 用Western blot检测calpain-3蛋白可在dysfedin蛋白表达缺失的LGMD患者中鉴别出2A型患者,该方法对临床辅助诊断LGMD2A有很好的价值.     

微量标本Western blot在诊断肢带型肌营养不良2A型中的应用

目的 探讨微量标本Western blot在诊断肢带型肌营养不良2A型中的应用.方法 对73例以肢体近端肌肉受累为首要临床表现的进行性肌营养不良患者行开放式骨骼肌活体组织检查,标本行组织化学染色以及抗dystrophin-N、C、R,α、β、γ、δ-sarcoglycan,dysferlin,caveolin-3单克隆抗体免疫组织化学染色.对其中已经除外dystrophin、sarcoglycans、dysferlin、caveolin-3蛋白异常的29例患者再行骨骼肌Western blot抗calpain-3、caveolin-3单克隆抗体免疫反应.结果 共有10例患者被确诊为肢带型肌营养不良2A型,其临床特点均为肢体近端肌无力起病,血清肌酸激酶不同程度升高,肌电图呈肌源性改变.组织化学染色见肌纤维大小不一,可见不同程度肌纤维变性、坏死和再生,结缔组织增生,6例见分叶状肌纤维;免疫组织化学染色见肌纤维中dystrophin、sarcoglycan、dysferlin、caveolin-3蛋白均正常表达.Western blot发现该10例患者相对分子质量94 000条带(calpain-3)与Duchenne/Becker型肌营养不良对照相比,呈完全(8例)或部分(2例)缺失;30 000区域附加条带均呈弱表达,22 000区域条带(caveolin-3)均正常表达.结论 骨骼肌微量标本Western blot是诊断LGMD2A的有效方法,适用于临床LGMD的分型诊断.     

B7-H1分子免疫病理在多发性肌炎中的临床研究

目的 通过免疫组化染色了解协同刺激分子B7-H1蛋白在多发性肌炎(PM)和肢带型肌营养不良2B型(LGMD 28)患者肌组织中的表达情况,探讨其在PM诊断和鉴别诊断中的意义.方法 选择苏州大学附属第一医院神经内科自2006年1月至2009年12月收治的43例PM患者(PM组),26例LGMD 2B型患者(LGMD 2B组)及21例肌活检正常者(对照组).对所有成员行肌肉活检,冰冻切片后进行常规HE染色、免疫组织化学染色,检测肌组织中B7-H1蛋白的表达.结果 (1)PM组与LGMD 2B型组肌肉活检普通病理染色结果相似,表现为不同程度的坏死、吞噬、再生现象,伴有不同程度的炎细胞浸润.(2)PM组B7-H1蛋白阳性表达主要定位于细胞膜,呈棕黄色至棕褐色,主要集中在有炎细胞浸润的变性、坏死肌纤维上;其肌组织中B7-H1蛋白表达水平比较LGMD2B型组和对照组成员肌组织中水平明显增高(分别为69.77%、26.92%、4.76%),差异有统计学意义(P<0.05).结论 协同刺激分子B7-H1在PM患者肌组织中高表达,参与了PM的免疫学发病机制,可成为PM与继发性炎细胞浸润性肌病相鉴别的免疫病理标志.     

B7-H1分子免疫病理在多发性肌炎中的临床研究

目的 通过免疫组化染色了解协同刺激分子B7-H1蛋白在多发性肌炎(PM)和肢带型肌营养不良2B型(LGMD 28)患者肌组织中的表达情况,探讨其在PM诊断和鉴别诊断中的意义.方法 选择苏州大学附属第一医院神经内科自2006年1月至2009年12月收治的43例PM患者(PM组),26例LGMD 2B型患者(LGMD 2B组)及21例肌活检正常者(对照组).对所有成员行肌肉活检,冰冻切片后进行常规HE染色、免疫组织化学染色,检测肌组织中B7-H1蛋白的表达.结果 (1)PM组与LGMD 2B型组肌肉活检普通病理染色结果相似,表现为不同程度的坏死、吞噬、再生现象,伴有不同程度的炎细胞浸润.(2)PM组B7-H1蛋白阳性表达主要定位于细胞膜,呈棕黄色至棕褐色,主要集中在有炎细胞浸润的变性、坏死肌纤维上;其肌组织中B7-H1蛋白表达水平比较LGMD2B型组和对照组成员肌组织中水平明显增高(分别为69.77%、26.92%、4.76%),差异有统计学意义(P<0.05).结论 协同刺激分子B7-H1在PM患者肌组织中高表达,参与了PM的免疫学发病机制,可成为PM与继发性炎细胞浸润性肌病相鉴别的免疫病理标志.     

dysferlinopathy患者40例临床和病理分析

目的 回顾性分析40例dysferlinopathy患者临床及活检骨骼肌组织化学、免疫组织化学染色病理变化,探讨dysferlinopathy的临床、病理诊断价值.方法 对40例dysferlinopathy患者临床资料进行分析;并对活检骨骼肌进行组织化学、免疫组织化学染色病理分析.结果 患者一般临床表现:进行性加重的肌无力、萎缩;根据病初受累肌群分为:肢带型肌营养不良2B型27例,Miyoshi远端型肌营养不良12例,以及胫骨前肌起病的远端肌病1例;血肌酸激酶水平呈不同程度的升高(134～ 19 795 U/L);全部患者肌电图呈肌源性损害;12例行骨骼肌MRI,其中9例行双侧大、小腿MRI检查,3例行双侧小腿MRI检查;近端肌受累为主4例、腓肠肌受累为主7例、胫骨前肌受累为主1例.骨骼肌活检组织化学染色病理表现:肌纤维变性、坏死和再生活跃,结缔组织不同程度增生,16例可见肌内膜、肌束膜和小血管周围炎性细胞浸润;抗-dysferlin单克隆抗体免疫组织化学染色结果显示,30例dysferlinopathy患者肌纤维膜上dysferlin蛋白完全缺失,10例重度减低.结论 本病典型临床表现为进行性加重肌无力、肌萎缩,根据病初受累肌群区分临床表型;血肌酸激酶显著增高,符合膜蛋白破坏型肌营养不良特点;骨骼肌MRI可清晰判断受累肌群范围、程度,帮助判断临床表型及选择合适的骨骼肌活检部位;病理特点为肌营养不良改变,部分患者有炎性细胞浸润,需要结合临床与炎性肌病相鉴别;肌纤维膜dysferlin蛋白缺失或重度减低,是dysferlinopathy分子病理诊断的重要依据.     

分子病理确诊的肢带型肌营养不良2A型患者五例临床及病理特点

目的 通过总结5例肢带型肌营养不良2A型(LGMD2A)患者的病例资料,探讨其临床和病理特点.方法 对病理诊断排除LGMD2B(7例)之后的30例分型未明的LGMD患者的肌肉标本进行免疫组织化学染色和钙激活蛋白酶-3(calpain-3)蛋白免疫印迹分析.结果 30例患者肌肉标本中有5例calpain-3蛋白条带缺失或遗留痕迹,从而被确诊为钙蛋白酶肌病,即LGMD2A.该5例患者起病年龄10～45岁,病程2～10年.其中2例的同胞兄妹有相似的临床表现,而父母无异常,提示本病的常染色体隐性遗传方式.5例均以下肢近端肌无力起病,肌萎缩明显;血清肌酸激酶639～8237 U/L,平均2502 U/L,肌电图均为肌源性损害.5例肌肉活体组织检查病理符合典型肌营养不良的病理特点,表现为肌纤维大小明显不等,可见坏死伴吞噬及再生,内核纤维增多,还原型辅酶Ⅰ四氮唑还原酶染色2例见分叶状纤维.5例LGMD2A患者dystrophin、caveolin-3和α-、β-、γ-、δ-sarcoglycan免疫组织化学染色均正常,2例dysferlin染色减低,余3例正常.结论 LGMD2A的临床表现和肌活体组织检查病理均缺乏特异性,免疫印迹分析有助于此病的诊断和鉴别诊断.     

dysferlinopathy患者八例临床及分子病理学特点

目的探讨中国dysferlinopathy患者的临床及分子病理学特点。方法分析已确诊的4例肢带型肌营养不良2B型、4例Miyoshi远位型肌营养不良患者的临床、骨骼肌活体组织检查和免疫组织化学染色病理特点。并以Duchenne肌营养不良4例，多发性肌炎和包涵体肌炎各2例作为对照。结果dysferlinopathy患者均以进行性加重的肌无力、萎缩为主要症状，符合进行性肌营养不良的临床表现。组织化学染色示dysferlinopathy患者出现不同程度的肌纤维变性、坏死、再生，结缔组织增生；多数病例可见炎性细胞浸润；抗dysferlin单克隆抗体免疫组织化学染色显示8例dysferlinopathy患者均出现dysferlin蛋自在肌纤维膜上和胞质内的缺失。结论（1）dysferlinopathy符合进行性肌营养不良的临床、病理表现；（2）抗dysferlin单克隆抗体免疫组织化学染色病理分析是诊断dysferlinopathy的可靠方法，值得临床推广应用。     

Dysferlin肌病的临床和病理特点分析(附6例报道)

目的:探讨dysferlin肌病的临床和病理特点。方法:对9例患者的肌肉病理标本进行组织化学和免疫组化染色检查,并对肌肉组织进一步行dysferlin蛋白的Westernblot分析。结果:9例患者中确诊6例为dysferlin肌病,病理表现均为肌源性损害,无边缘空泡,其中2例患者的病理分析有炎细胞浸润。根据临床表现特点,6例患者中有3例为Miyoshi肌病(MM),2例为肢带型肌营养不良2B型(LGMD2B),1例为远端前群肌病(DACM)。结论:Dysferlin肌病在肌电图上为肌源性损害、肌酶显著升高,其临床表现多样,dysferlin免疫组化染色联合Westernblot有着重要诊断意义。     

B7-H1分子免疫病理在多发性肌炎中的临床研究

目的 通过免疫组化染色了解协同刺激分子B7-H1蛋白在多发性肌炎(PM)和肢带型肌营养不良2B型(LGMD 28)患者肌组织中的表达情况,探讨其在PM诊断和鉴别诊断中的意义.方法 选择苏州大学附属第一医院神经内科自2006年1月至2009年12月收治的43例PM患者(PM组),26例LGMD 2B型患者(LGMD 2B组)及21例肌活检正常者(对照组).对所有成员行肌肉活检,冰冻切片后进行常规HE染色、免疫组织化学染色,检测肌组织中B7-H1蛋白的表达.结果 (1)PM组与LGMD 2B型组肌肉活检普通病理染色结果相似,表现为不同程度的坏死、吞噬、再生现象,伴有不同程度的炎细胞浸润.(2)PM组B7-H1蛋白阳性表达主要定位于细胞膜,呈棕黄色至棕褐色,主要集中在有炎细胞浸润的变性、坏死肌纤维上;其肌组织中B7-H1蛋白表达水平比较LGMD2B型组和对照组成员肌组织中水平明显增高(分别为69.77%、26.92%、4.76%),差异有统计学意义(P<0.05).结论 协同刺激分子B7-H1在PM患者肌组织中高表达,参与了PM的免疫学发病机制,可成为PM与继发性炎细胞浸润性肌病相鉴别的免疫病理标志.

Abstract：

Objective To analyze the protein expression of costimulatory molecule B7-H1 in muscular tissues of patients with polymyositis (PM) and limb-girdle muscular dystrophy-2B type (LGMD-2B), and investigate its relevance to the pathogenesis of PM and its role in the diagnosis and identification of PM. Methods Forty-three patients with PM, 26 patients with LGMD -2B and 21 with normal muscle biopsy were recruited. Muscle biopsy was performed before frozen sections, and then, HE staining and immunohistochemistry were employed to detect the protein expression of B7-H1 in muscle tissues of each group. Results The results of HE staining of muscle tissues in the PM group and LGMD 2B group were very similar; varying degrees of necrosis, phagocytosis and regeneration phenomenon were noted with varying degrees of inflammatory cell infiltration. In PM group,muscle-related expression of B7-H1 was observed on the surface of muscle fibers (the cytomembrane). It was localized in areas where inflammatory cells lay in close apposition to damaged or non-necrotic muscle fibers. The B7-H1 protein in the PM muscular tissue was significantly increased as compared with that in the LGMD -2B tissue and normal tissue (69.77%, 26.92%, 4.76%, P<0.05). Conclusion Costimulatory molecule B7-H1 is highly expressed in the muscular tissue of patients with PM and it may be involved in the immunological pathogenesis of PM. It can be used to make a distinction between PM and other myopathies that have secondary inflammatory changes.     

Intracellular accumulation and reduced sarcolemmal expression of dysferlin in limb--girdle muscular dystrophies

Dysferlin has recently been identified as a novel gene involved in limb-girdle muscular dystrophy type 2B (LGMD2B) and its allelic disease, Miyoshi myopathy. The predicted structure of dysferlin suggests that it is a transmembrane protein possibly involved in membrane fusion. Thus, unlike previously identified structural proteins in muscular dystrophy, dysferlin is likely involved in a novel pathogenic mechanism for this disease. In this study, we have analyzed the expression of dysferlin in skeletal muscle of patients with disruptions in the dystrophin-glycoprotein complex and patients with a clinical diagnosis of LGMD2B or Miyoshi myopathy. We show expression of dysferlin at the sarcolemma in normal muscle and reduced sarcolemmal expression along with accumulation of intracellular staining in dystrophic muscle. Electron microscopy in Miyoshi myopathy biopsies suggests that the cytoplasmic staining could be a result of the abundance of intracellular vesicles. Our results indicate that dysferlin expression is perturbed in LGMD and that both mutations in the dysferlin gene and disruption of the dystrophin-glycoprotein complex can lead to the accumulation of dysferlin within the cytoplasm.     

Dysferlin protein analysis in limb-girdle muscular dystrophies

Dysferlin is the protein product of the DYSF gene mapped at 2p31, which mutations cause limb-girdle muscular dystrophy type 2B (LGMD2B) and Miyoshi myopathy. To date, nine autosomal recessive forms (AR-LGMD) have been identified: four genes, which code for the sarcoglycan glycoproteins, are associated with both mild and severe forms, the sarcoglycanopathies (LGMD2C, 2D, 2E and 2F). The other five forms, usually causing a milder phenotype are LGMD2A (calpain 3), LGMD2B (dysferlin), LGMD2G (telethonin), LGMD2H (9q31-11), and LGMD21 (19q13.3). We studied dysferlin expression in a total of 176 patients, from 166 LGMD families: 12 LGMD2B patients, 70 with other known forms of muscular dystrophies (LGMD2A, sarcoglycanopathies, LGMD2G), in an attempt to assess the effect of the primary gene-product deficiency on dysferlin. In addition, 94 still unclassified LGMD families were screened for dysferlin deficiency. In eight LGMD2B patients from five families, no dysferlin was observed in muscle biopsies, both through immunofluorescence (IF) and Western blot methodologies, while in two families, a very faint band was detected. Both patterns, negative or very faint bands, were concordant in patients belonging to the same families, suggesting that dysferlin deficiency is specific to LGMD2B. Myoferlin, the newly identified homologue of dysferlin was studied for the first time in LGMD2B patients. Since no difference was observed between patients mildly and severely affected, this protein do not seem to modify the phenotype in the present dysferlin-deficient patients. Dystrophin, sarcoglycans, and telethonin were normal in all LGMD2B patients, while patients with sarcoglycanopathies (2C, 2D, and 2E), LGMD2A, LGMD2G, and DMD showed the presence of a normal dysferlin band by Western blot and a positive pattern on IF. These data suggest that there is no interaction between dysferlin and these proteins. However, calpain analysis showed a weaker band in four patients from two families with intra-familial concordance. Therefore, this secondary deficiency of calpain in LGMD2B families, may indicate an interaction between dysferlin and calpain in muscle. Dysferlin was also present in cultured myotubes, in chorionic villus, and in the skin. Dysferlin deficiency was found in 24 out of a total of 166 Brazilian AR-LGMD families screened for muscle proteins (approximately 14%), thus representing the second most frequent known LGMD form, after calpainopathy, in our population.     

Dysferlin interacts with affixin (beta-parvin) at the sarcolemma

The dysferlin gene is defective in Miyoshi myopathy (MM) and limb girdle muscular dystrophy type 2B (LGMD2B). Dysferlin is a sarcolemmal protein that is implicated in calcium-dependent membrane repair. Affixin (beta-parvin) is a novel, integrin-linked kinase-binding protein that is involved in the linkage between integrin and the cytoskeleton. Here we show that affixin is a dysferlin binding protein that colocalizes with dysferlin at the sarcolemma of normal human skeletal muscle. The immunoreactivity of affixin was reduced in sarcolemma of MM and LGMD2B muscles, although the total amount of the affixin protein was normal. Altered immunoreactivity of affixin was also observed in other muscle diseases including LGMD1C, where both affixin and dysferlin showed quite similar changes with a reduction of sarcolemmal staining with or without cytoplasmic accumulations. Colocalization of dysferlin and affixin was confirmed by immunofluorescence analysis using dysferlin-expressing C2 myoblasts. Wild-type and mutant dysferlin colocalized with endogenous affixin. The interaction of dysferlin and affixin was confirmed by immunoprecipitation study using normal human and mouse skeletal muscles. Using immunoprecipitation with deletion mutants of dysferlin, we have identified that C-terminal region of dysferlin is an apparent binding site for affixin. We also found N-terminal calponin homology domain of affixin as a binding site for dysferlin. Our results suggest that affixin may participate in membrane repair with dysferlin.