Hohlfeld R, Engel A G, Goebels N, Behrens L
Department of Neurology, Klinikum Grosshadern, University of Munich, Germany.
Curr Opin Rheumatol. 1997 Nov;9(6):520-6. doi: 10.1097/00002281-199711000-00007.
The inflammatory myopathies include dermatomyositis, polymyositis, and inclusion body myositis. In dermatomyositis, muscle fiber injury is secondary to an antibody- or immune-complex-mediated immune response against a vascular-endothelial component. In polymyositis and inclusion body myositis, CD8+ T cells and macrophages invade and eventually destroy initially nonnecrotic muscle fibers. The autoaggressive T cells have the phenotype of activated (HLA-DR+) memory (CD45RO+) cells. T-cell receptor analyses indicate that the autoaggressive T cells are oligoclonal. In inflammatory lesions, muscle fibers express various cytoplasmic and surface molecules that are not detectable in normal fibers. These molecules, which include HLA class I antigens, heat-shock proteins, adhesion molecules, and Fas, are probably induced by locally secreted cytokines. The autoaggressive CD8+ T cells harbor granules containing perforin that aggregate near the contact zone with the target muscle fiber. This is consistent with a perforin- and secretion-dependent mechanism of muscle fiber injury. Many invaded muscle fibers also express the Fas "death receptor," but signs of apoptosis are absent.
炎症性肌病包括皮肌炎、多发性肌炎和包涵体肌炎。在皮肌炎中，肌纤维损伤继发于针对血管内皮成分的抗体或免疫复合物介导的免疫反应。在多发性肌炎和包涵体肌炎中，CD8 + T细胞和巨噬细胞侵入并最终破坏最初未坏死的肌纤维。自身攻击性T细胞具有活化（HLA - DR +）记忆（CD45RO +）细胞的表型。T细胞受体分析表明，自身攻击性T细胞是寡克隆的。在炎症病变中，肌纤维表达多种在正常纤维中无法检测到的细胞质和表面分子。这些分子包括HLA I类抗原、热休克蛋白、黏附分子和Fas，可能是由局部分泌的细胞因子诱导产生的。自身攻击性CD8 + T细胞含有含有穿孔素的颗粒，这些颗粒在与靶肌纤维的接触区附近聚集。这与肌纤维损伤的穿孔素和分泌依赖性机制一致。许多被侵入的肌纤维也表达Fas“死亡受体”，但不存在凋亡迹象。
