Englund P, Lindroos E, Nennesmo I, Klareskog L, Lundberg I E
Department of Medicine, Rheumatology Unit, Karolinska Institutet, Stockholm, Sweden.
Am J Pathol. 2001 Oct;159(4):1263-73. doi: 10.1016/S0002-9440(10)62513-8.
The aim of our study was to address the question of whether muscle fibers express major histocompatibility complex (MHC) class II in inflammatory myopathies. For this purpose we performed a systematic study of MHC class II antigen expression on muscle fiber membranes in muscle tissue from polymyositis and dermatomyositis patients in various stages of disease activity. Thirty-two patients with classical clinical signs of myositis were divided into subgroups depending on duration of clinical signs of myositis and presence or absence of inflammatory infiltrates in muscle tissue. Immunohistochemistry as well as double-immunofluorescence stainings were used to identify the presence of MHC class II in muscle tissue. MHC class I was included for comparison. Quantification of positive staining was performed using an image analysis system in addition to evaluation by manual microscopic scoring and laser confocal microscopy. It was demonstrated that a significant proportion of skeletal muscle fibers in inflammatory myopathies express MHC class II as well as MHC class I and that MHC antigen expression is independent of the inflammatory cell infiltration. Furthermore, there were no differences in staining pattern between polymyositis and dermatomyositis patients. Our results indicate that MHC class II and MHC class I molecules may be involved in initiating and maintaining the pathological condition in myositis rather than only being a consequence of a preceding local inflammation.
我们研究的目的是解决炎性肌病中肌纤维是否表达主要组织相容性复合体(MHC)II类分子这一问题。为此,我们对处于疾病活动不同阶段的多发性肌炎和皮肌炎患者肌肉组织中肌纤维膜上的MHC II类抗原表达进行了系统研究。32例有典型肌炎临床症状的患者根据肌炎临床症状持续时间以及肌肉组织中有无炎性浸润被分为不同亚组。采用免疫组织化学以及双重免疫荧光染色来鉴定肌肉组织中MHC II类分子的存在情况。同时纳入MHC I类分子作为对照。除了通过手动显微镜评分和激光共聚焦显微镜评估外,还使用图像分析系统对阳性染色进行定量分析。结果表明,炎性肌病中有相当比例的骨骼肌纤维表达MHC II类分子以及MHC I类分子,且MHC抗原表达与炎性细胞浸润无关。此外,多发性肌炎和皮肌炎患者之间的染色模式没有差异。我们的结果表明,MHC II类分子和MHC I类分子可能参与了肌炎病理状态的启动和维持,而不仅仅是先前局部炎症的结果。