Dystrophin abnormalities in polymyositis and dermatomyositis

The expression of dystrophin in muscle biopsies from nine cases of polymyositis, ten cases of juvenile dermatomyositis and three adults with dermatomyositis was studied by Western blot analysis and immunocytochemistry. Five antibodies corresponding to different N- and C-terminal regions of the dystrophin gene were used. Sixteen of the 22 cases (73%) showed an abnormality in the expression of dystrophin on Western blot analysis, either with a reduced molecular weight protein or a reduced amount. Immunostaining was abnormal in 11 out of 19 cases (58%) and showed varying degrees of discontinuity or loss of sarcolemmal staining. Immunolabelling of these areas with antibodies to beta-spectrin was normal implying that the changes were not caused by a loss of the sarcolemma. These results show that secondary changes in the expression of dystrophin can occur in the absence of an abnormality in the corresponding gene and that dystrophin cannot be used in isolation as a diagnostic marker for muscular dystrophy.     

Quantitative electromyography in polymyositis and dermatomyositis

Twelve patients with polymyositis or dermatomyositis were examined repeatedly during the course of the illness by muscle strength tests, serum enzyme determinations, frequency analysis of the electromyographic signal, and estimations of the spontaneous activity. All methods can be used to follow the course of the disease. Increasing muscle strength was correlated to decreasing serum enzyme values, decreasing spontaneous activity, and decreasing proportion of high-frequency components in the EMG signal, except during the initial period of treatment, when a temporary increase in high-frequency components was recorded.     

An overview of polymyositis and dermatomyositis

Polymyositis and dermatomyositis are inflammatory myopathies that differ in their clinical features, histopathology, response to treatment, and prognosis. Although their clinical pictures differ, they both present with symmetrical, proximal muscle weakness. Treatment relies mainly upon empirical use of corticosteroids and immunosuppressive agents. A deeper understanding of the molecular pathways that drive pathogenesis, careful phenotyping, and accurate disease classification will aid clinical research and development of more efficacious treatments. In this review we address the current knowledge of the epidemiology, clinical characteristics, diagnostic evaluation, classification, pathogenesis, treatment, and prognosis of polymyositis and dermatomyositis. Muscle Nerve 51 :638–656, 2015     

Oropharyngeal dysphagia in polymyositis/dermatomyositis

The nature of the oropharyngeal dysphagia in polymyositis/dermatomyositis (PM/DM) has been investigated by EMG methods. Nineteen patients with PM/DM were studied. The oropharyngeal phase of swallowing was evaluated by the electrophysiological methods measuring the laryngeal relocation time, pharyngeal transit time and the triggering of the pharyngeal phase of swallowing reflex. The EMG of cricopharyngeal muscle of the upper esophageal sphincter was also recorded in 10 patients. The patients have been compared with a group of 22 healthy controls matched with age and gender. Dysphagia limit was also measured for all patients and control subjects. Fourteen out of 19 patients could not swallow 20 ml or less amount of water at one go and divided the bolus into two or more pieces (piecemeal deglutition) in comparison to normal subjects. In PM/DM patients, the triggering of the swallowing reflex for the voluntarily initiated swallow was normal while the pharyngeal phase of swallowing was significantly prolonged. The cricopharyngeal sphincter muscle EMG demonstrated severe abnormalities in halves of the patients investigated. These findings demonstrated the weakness of the striated oropharyngeal muscles. Cricopharyngeal sphincter muscle was affected less frequently and showed either hyperreflexic or hyporeflexic states during swallowing. It is concluded that the pharyngeal stage of oropharyngeal swallowing is mainly involved in patients with PM/DM.     

Monocyte/macrophage differentiation in dermatomyositis and polymyositis

Recent advances have revealed significant differences in the pathogenesis of inflammatory myopathies. To determine whether different patterns of macrophage differentiation are a useful tool to delineate the major groups of inflammatory myopathies, the muscle biopsies of 11 patients with dermatomyositis and 12 patients with polymyositis were studied using different macrophage markers. In polymyositis, the early-activation markers MRP14 and 27E10 stained the majority of macrophages, which were recognized by the pan-macrophage marker Ki-M1P and which were located primarily in the endomysium. In dermatomyositis, macrophages predominantly expressed the late-activation marker 25F9 and were found mainly in the perimysium. Thus, the location and presence of different subsets of macrophages distinguish dermatomyositis and polymyositis. The predominance of early-activated macrophages in polymyositis indicates a more acute disease process. The findings in dermatomyositis, by contrast, suggest a role of persistent monocytes/macrophages in the disease process.     

多发性肌炎与皮肌炎的临床病理研究

目的 探讨多发性肌炎和皮肌炎的病理变化、发病机制、治疗效果和预后。方法 按照Bohan的多发性肌炎和皮肌炎的诊断分类标准,将本研究中的58例多发性肌炎和皮肌炎患者分成4类亚型。对全部患者进行肌肉病例及血甭酶学检查,并进行治疗观察。结果 临床表现以肌无力、肌肉压血清酶谱增高、肌电图及病理学异常等为特征。但各型之间又有差异,提示存在不同的发病机制,治疗以激素为主,必要时加用免疫抑制剂。结论 预后治疗时机密切相关,症状随血清酶谱下降而了转,肺部感染、心肌病损及病程迁延提示预后不良。     

多发性肌炎、皮肌炎诊断治疗中的几个问题

多发性肌炎(polymyositis，PM)、皮肌炎(dermatomyositis，DM)是一组免疫性炎性肌病，其共同表现为对称性四肢近端肌肉及延髓支配肌肉力弱，血清肌酸激酶(CK)升高，肌电图呈肌源性改变，肌肉病理表现为肌纤维坏死、再生和炎性细胞浸润。近年来已经对其临床表现多样性的认识，发病机制的了解，以及治疗取得了一些进展，但是对发病机制尚未完全阐明，对各项诊断技术的评价尚未标准化，对治疗规律缺乏精确了解，对繁杂的治疗方法尚需规范。因此，有必要对一些问题进行深入的研究、讨论。     

单纯性多发性肌炎和皮肌炎的病程演变

目的　探讨单纯性多发性肌炎和皮肌炎的病程演变规律,以期获得对该病较全面的认识,指导临床治疗。方法　对６２ 例单纯性多发性肌炎和皮肌炎病程演变、临床病理和治疗相互间关系进行分析研究。结果　起病急、进展快、病情在半年内发展至高峰者,临床上以发热、肌痛、颈肌无力和吞咽困难常见,病理以急性炎症改变突出,及时治疗疗效好;而起病隐匿、进展缓慢、病情半年以上仍在进展者,以肢体肌无力多见,病理以间质改变更突出,预后较差,易迁延。结论　我们认为,病情在半年以内达高峰者可称为急性或亚急性单纯性多发性肌炎或皮肌炎,病情超过半年仍在进展者可称为慢性多发性肌炎或皮肌炎。     

Frequency of relapses in patients with polymyositis and dermatomyositis

The frequency of clinical and biochemical relapses was determined in a group of 50 patients with polymyositis (PM), dermatomyositis (DM), or overlap syndromes who were followed for periods of up to 13 years. Relapses occurred in 30 of the 50 patients (60%) during the period of follow-up. The annual relapse rate was not significantly different in the three groups of patients. Subclinical relapses occurred in each group but were less frequent in the DM than in the PM and overlap groups. Relapses could occur at any time but were more frequent during periods of stable maintenance therapy. There was no correlation between relapses and initial disease severity, delay to diagnosis and commencement of treatment, or any class I or II histocompatibility locus antigen. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21: 1668–1672, 1998     

磁共振成像在多发性肌炎、皮肌炎诊断中的应用

目的 研究多发性肌炎(PM)、皮肌炎(DM)的磁共振成像(MRI)表现，评价MRI在PM及DM诊断中应用价值。方法 对5例PM及4例DM患者行MRI检查，选择骨盆、双侧大腿及小腿肌肉，采用自旋回波序列(SE)、快速自旋回波序列(FSE)及短时反转恢复序列(STIR)进行扫描。结果 5例PM及4例DM患者的受累肌群均表现为斑片状等T1长T2异常信号，2例PM患者尚可见小斑片状短T1长T2异常信号影；6例患者肌筋膜增厚，呈长T2线样高信号改变；4例DM患者的表皮及皮下结缔组织尚可见条带状及网格状长T1长T2异常信号影。受累肌群主要表现为炎症水肿样改变，晚期受累肌肉可见少量脂肪替代改变；病变双侧不对称，以内收肌受累最重，股中间肌受累最轻。结论 PM与DM患者的MRI表现具有一定的特征性，MRI能为PM及DM的定位诊断、疗效判断及病情随访提供客观资料，并能为临床选取准确的活检部位提供帮助。     

Serum immunogloblin levels in myasthenia gravis, polymyositis, and dermatomyositis.

Analyses of serum immunoglobulin (Ig) levels were performed in patients with myasthenia gravis, polymyositis and dermatomyositis, and in normal subjects. The mean IgG levels were elevated in the disease groups and there was minimal depression of serum IgM levels in nonthymectomized myasthenic patients. There was no consistent pattern with regard to selective immunoglobulin class abnormalities, effect of thymectomy in serial studies, and no evidence of gross humoral immunological deficiency as manifested by consistent depression of serum IgA, IgG, or IgM in the disease groups.     

Spontaneous electrical muscle fiber activity in polymyositis and dermatomyositis

Forty patients with polymyositis or dermatomyositis underwent detailed electromyographic evaluation. The paraspinal muscles of all patients were examined, as were several extremity muscles. The distribution of fibrillation potentials (FPs) in different muscles is discussed. FPs were most frequent in paraspinal muscles. We conclude that, for any patient suspected of having a myopathy, electromyographic examination should include the paraspinal muscles.     

皮肌炎和多发性肌炎175例神经传导检测

目的 研究皮肌炎(dermatomyositis,DM)和多发性肌炎(polymyositis,PM)合并神经传导检测(NCS)异常患者的临床和电生理特点以及病因探讨.方法 收集2005年1月到2008年9月中国医学科学院北京协和医院病房收治的DM或PM确诊病例175例,对其临床和NCS结果进行回顾性分析.结果 175例患者中,NCS异常者66例,其中明确的周围神经病32例(48.5%),不能肯定为周围神经损害者34例(51.5%).合并周围神经损害的DM或PM患者恶性肿瘤(3/32,9.3%)、其他免疫病(6/32,18.8%)的发生率较无周围神经损害的DM或PM患者(4/109,3.7%;7/109,6.4%)有明显增加(X2=13.653,P=0.003).结论 合并周围神经损害的DM或PM患者恶性肿瘤、其他免疫病的发生率明显增加,NCS可以为临床早期诊断提供更多的提示和帮助.     

皮肌炎和多发性肌炎175例神经传导检测

目的 研究皮肌炎(dermatomyositis,DM)和多发性肌炎(polymyositis,PM)合并神经传导检测(NCS)异常患者的临床和电生理特点以及病因探讨.方法 收集2005年1月到2008年9月中国医学科学院北京协和医院病房收治的DM或PM确诊病例175例,对其临床和NCS结果进行回顾性分析.结果 175例患者中,NCS异常者66例,其中明确的周围神经病32例(48.5%),不能肯定为周围神经损害者34例(51.5%).合并周围神经损害的DM或PM患者恶性肿瘤(3/32,9.3%)、其他免疫病(6/32,18.8%)的发生率较无周围神经损害的DM或PM患者(4/109,3.7%;7/109,6.4%)有明显增加(X2=13.653,P=0.003).结论 合并周围神经损害的DM或PM患者恶性肿瘤、其他免疫病的发生率明显增加,NCS可以为临床早期诊断提供更多的提示和帮助.     

Magnetic resonance imaging of the muscles in patients with polymyositis and dermatomyositis

Magnetic resonance imaging (MRI) of the muscles was performed in patients with polymyositis and dermatomyositis. Lesions with high intensity on T2-weighted image, but normal intensity on T1-weighted image, were observed in 7 of 8 patients in the active stage of the disease. Following clinical improvement with corticosteroid therapy in 4 patients, the high intensity lesions reverted to normal. The high intensity lesions seen on T2-weighted image in the active stage may represent edema and inflammation of the muscle. MRI of the muscle may serve as a diagnostic tool and be useful for follow-up of the patients with polymyositis or dermatomyositis.     

Clinico-developmental aspects in 44 cases of polymyositis/dermatomyositis

A retrospective study, paying particular attention to the clinical and evolutive aspects of the disease, was performed on 44 subjects affected by polymyositis/dermatomyositis (PM/DM) and hospitalized at the Institute of Medical Clinics of the 1st School of Medicine of Naples University. On the basis of the different clinical pictures, the cases were classified into the following groups: primary PM (4); primary DM (19); DM/PM associated with malignancy (6); childhood DM/PM (3); PM/DM associated with connective tissue disorders (12). Diagnosis was established in terms of the following criteria: a) symmetrical and mostly proximal bilateral muscle weakness (100%); b) elevation of serum enzymes (86.3%); c) electromyographic findings of myopathy sometimes with fibrillation potentials, increased insertional irritability and pseudo-myotonic discharges (93.1%); d) muscle biopsy changes compatible with a clinical form of polymyositis (83.3% out of 30 cases); e) dermatological manifestations including particularly pink or lilac edema-erythema over the periorbital areas, wine-red maculae, Gottron's sign, "poikiloderma vasculare atrophicans", telangiectasias and skin vasculitis (86.3%). An involvement of the extraneural apparatus and organs was present in 40 patients; the most damaged was the osteoarticular apparatus, followed by esophagus, lung, heart and kidney; such pathology was rarely present in the childhood form. A follow-up of the disease has been performed in 36 cases and the therapy consisted fundamentally of high dose corticosteroids (mostly prednisone), associated, in a minority of cases, with methotrexate. A clinical improvement was observed in most cases and a remission of the disease in part of the latter. However, a worsening of the illness was noticed only in the patients suffering from PM/DM associated with malignancy, and mortality rate was 11.1% in all.     

Successful treatment of dermatomyositis and polymyositis with anti-tumor-necrosis-factor-alpha: preliminary observations

Tumor necrosis factor alpha neutralization seems a rational therapy for myositis because this proinflammatory cytokine has been implicated in the pathogenesis of this disorder. Until now, we have treated 2 patients with a chimeric anti-TNF-alpha monoclonal antibody (infliximab). Both patients demonstrated a marked and sustained subjective and objective improvement without the occurrence of any side effects. These preliminary results suggest that anti-TNF-alpha treatment with infliximab is a safe and rapidly effective therapy for myositis.     

Immunolocalization of protectin (CD59) and macrophages in polymyositis and dermatomyositis

Immunohistochemical stainings for protectin (CD59) and for the macrophage/monocyte antigen were performed in muscle specimens of polymyositis (PM) and dermatomyositis (DM) patients. In control muscles, a granular immunostaining of CD59 at the surface of 10-15% from among muscle fibers and an intense reaction in endothelia of blood vessels were noted. Strong immunostaining appeared inside vacuoles of vacuolar degeneration changes of muscle fibers, and in regenerating muscle fibers in PM and DM. No macrophages were found next to the CD59 positive muscle regions. The results seem to strongly support a role of the complement (C) system and of the factors protecting cells from the C-induced damage in the mechanism of muscle injury in PM and DM. The findings can have treatment implications.     

多发性肌炎和皮肌炎201例临床病理研究

201例多发性肌炎和皮肌炎,根据Bohan分型标准分成五组类型,其临床上以肢体肌无力、皮肤损害、疼痛、血肌酶升高、肌电图改变、肌活检肌纤维坏死及炎性细胞浸润为特征,但不同类型有所侧重,揭示其发病机制不同。治疗体会仍以激素为首选,必要时加用免疫抑制剂,开始治疗时间不应晚于1.5年,防治肺部感染是改善预后的重要措施之一。