散发性包涵体肌炎的研究进展

Research progress of sporadic inclusion body myositis

散发性包涵体肌炎（sporadic inclusion body myositis，sIBM）是特发性炎性肌病（idiopathic inflammatory myopathy，IIM）的一种，好发于年龄大于50岁的男性人群；患者通常隐匿起病，随后出现缓慢进行性肌无力和肌萎缩；该病可能与多种因素有关。实验室检查显示患者肌酶水平正常或轻度升高，肌活检提示肌内膜炎性细胞浸润、肌纤维内出现镶边空泡、淀粉样蛋白沉积以及肌纤维数量的减少，电镜下可见管状细丝包涵体。在2011年召开的第188届欧洲神经肌肉中心（European Neuromuscular Center，ENMC）会议上确立了诊断该疾病的最新标准。近几年研究者发现了一种新的自身抗体一抗cN1A自身抗体（cytoplasmic5’nucleotidase 1A，cN1A），并证实与sIBM存在相关性。包涵体肌炎对免疫治疗的反应性欠佳，其预后与患者的年龄、肌纤维的受累情况、是否合并其他疾病有关。因而研究该病的流行病学、病因及发病机制、临床表现、实验室检查、诊断及治疗具有重要意义。

Sporadic inclusion body myositis （sIBM） belongs to the idiopathic inflammatory myopathy （IIM）. sIBM often affect old male over 50 years of age with usually insidious onset, followed by a slowly progressive muscle weakness and atrophy. Laboratory examination shows the muscle enzyme level in patients is normal or mildly elevated. Muscle biopsy is characterized with endomysial inflammatory cell infiltration, rimmed vacuoles within muscle fibers, amyloid deposition and decreased muscle fibers. Under electron microscope, tubu- lar filament inclusion is often observed. The new standard for the diagnosis of sIBM was established by the euro- pean neuromuscular center （ENMC） in 2011. In recent years, researchers have discovered a new autoantibody, the anti-cN1A （cytoplasmic 5＇-nucleotidase 1A,cN1A） autoantibody,and confirmed its correlation with sIBM. Inclusion body myositis responds to immunotherapy poorly. The prognosis of the patients is related with patients＇ age, involvement of muscle fiber, and the combination of other diseases. It is important to discusses the epidemi- ology, etiology, pathogenesis, clinical manifestation, diagnosis and treatment of sIBM.