Grundtman Cecilia, Lundberg Ingrid E
Curr Rheumatol Rep. 2006 Jun;8(3):188-95. doi: 10.1007/s11926-996-0024-4.
The idiopathic inflammatory myopathies, myositis, are characterized by a chronic course with decreased muscle endurance and by infiltrates of T lymphocytes and macrophages in muscle tissue. Treatment with immunosuppressives rarely leads to recovery of muscle function, despite abolishment of inflammatory cell infiltrates in muscle tissue. Therefore, other mechanisms than immune-mediated muscle fiber damage are likely to contribute to the pathogenesis. One such non-immune-mediated muscle dysfunction could be caused by a disturbed microcirculation due to capillary loss or to phenotypically changed endothelial cells in the capillaries. These aberrations may affect the micro-environment of muscle tissue and lead to local tissue hypoxia with development of a secondary metabolic myopathy. Another possible non-immune-mediated mechanism leading to muscle dysfunction is the newly identified endoplasmatic reticulum (ER) stress response in myositis. The ER stress response is thought to be a consequence of the up-regulation of major histocompatibility complex class I in muscle fibers. These newly identified molecular pathways could play a major role in the pathogenesis of myositis and could be important targets in the development of new therapies.
特发性炎性肌病，即肌炎，其特征为病程慢性、肌肉耐力下降，以及肌肉组织中有T淋巴细胞和巨噬细胞浸润。尽管免疫抑制剂治疗可消除肌肉组织中的炎性细胞浸润，但很少能使肌肉功能恢复。因此，除免疫介导的肌纤维损伤外，其他机制可能也参与了发病过程。一种非免疫介导的肌肉功能障碍可能是由于毛细血管丧失或毛细血管内皮细胞表型改变导致微循环紊乱引起的。这些异常可能会影响肌肉组织的微环境，导致局部组织缺氧，并引发继发性代谢性肌病。另一种导致肌肉功能障碍的非免疫介导机制是最近在肌炎中发现的内质网（ER）应激反应。内质网应激反应被认为是肌纤维中主要组织相容性复合体I类上调的结果。这些新发现的分子途径可能在肌炎的发病机制中起主要作用，并且可能成为新疗法开发的重要靶点。
