Lundberg Ingrid E, Fujimoto Manabu, Vencovsky Jiri, Aggarwal Rohit, Holmqvist Marie, Christopher-Stine Lisa, Mammen Andrew L, Miller Frederick W
Division of Rheumatology, Department of Medicine, Solna, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden.
Department of Dermatology, Osaka University Graduate School of Medicine, Suita, Japan.
Nat Rev Dis Primers. 2021 Dec 2;7(1):86. doi: 10.1038/s41572-021-00321-x.
Idiopathic inflammatory myopathies (IIM), also known as myositis, are a heterogeneous group of autoimmune disorders with varying clinical manifestations, treatment responses and prognoses. Muscle weakness is usually the classical clinical manifestation but other organs can be affected, including the skin, joints, lungs, heart and gastrointestinal tract, and they can even result in the predominant manifestations, supporting that IIM are systemic inflammatory disorders. Different myositis-specific auto-antibodies have been identified and, on the basis of clinical, histopathological and serological features, IIM can be classified into several subgroups - dermatomyositis (including amyopathic dermatomyositis), antisynthetase syndrome, immune-mediated necrotizing myopathy, inclusion body myositis, polymyositis and overlap myositis. The prognoses, treatment responses and organ manifestations vary among these groups, implicating different pathophysiological mechanisms in each subtype. A deeper understanding of the molecular pathways underlying the pathogenesis and identifying the auto-antigens of the immune reactions in these subgroups is crucial to improving outcomes. New, more homogeneous subgroups defined by auto-antibodies may help define disease mechanisms and will also be important in future clinical trials for the development of targeted therapies and in identifying biomarkers to guide treatment decisions for the individual patient.
特发性炎性肌病（IIM），也称为肌炎，是一组临床表现、治疗反应和预后各异的自身免疫性疾病。肌肉无力通常是典型的临床表现，但其他器官也可能受到影响，包括皮肤、关节、肺、心脏和胃肠道，甚至可能导致主要表现，这表明IIM是全身性炎性疾病。已经鉴定出不同的肌炎特异性自身抗体，根据临床、组织病理学和血清学特征，IIM可分为几个亚组——皮肌炎（包括无肌病性皮肌炎）、抗合成酶综合征、免疫介导的坏死性肌病、包涵体肌炎、多发性肌炎和重叠性肌炎。这些组之间的预后、治疗反应和器官表现各不相同，这意味着每个亚型都有不同的病理生理机制。深入了解发病机制背后的分子途径并确定这些亚组中免疫反应的自身抗原对于改善治疗结果至关重要。由自身抗体定义的新的、更同质的亚组可能有助于确定疾病机制，在未来针对靶向治疗开发的临床试验以及识别指导个体患者治疗决策的生物标志物方面也将具有重要意义。
