Idiopathic Inflammatory Myopathy and the COVID-19 Pandemic

特發性炎症肌病變與COVID-19之相關性

特發性炎症性肌病變(IIM)是一種具有多種臨床表現的自體免疫性疾病，包括肌肉無力、肌痛以及各種肌肉外表現。遺傳和環境風險因素已被證明與IIM的發展有關。根據歐洲抗風濕病聯盟／美國風濕病學會(European League Against Rheumatism／American College of Rheumatology)的分類標準，IIM分為幾個臨床血清學亞組：多發性肌炎(PM)、皮肌炎（DM；包括成人和青少年（JDM））、無肌病變性DM(ADM)、抗合成酶綜合徵候群(ASS)、包涵體肌炎(IBM)、免疫介導壞死性肌病變(IMNM)、肌病性肌病變(HDM)、癌症相關性肌炎與重疊型肌炎(OM)。肌炎特異性自體抗體(MSA)和肌炎相關自體抗體(MAA)的鑑定已被證明有助於判斷各種IIM亞組的分類。近來研究發現2019新冠病毒肺炎(COVID-19)患者具有類似的IIM臨床症狀表現。在這篇小型綜論中，我整理關於IIM亞組、MSA／MAA以及IIM與COVID-19疾病間的相關性，包括疾病介紹、診斷挑戰、檢測限制以及目前提出的疾病機制等當前知識。未來如果能夠早期診斷出不同IIM亞組分類，將有助於避免後續嚴重併發症的發生，例如快速進展的間質性肺病，並且將有機會改善IIM和COVID-19患者的治療結果和生存率。

Idiopathic inflammatory myopathy (IIM) is an autoimmune disease with diverse clinical manifestations, including muscle weakness, myalgia, and extra muscular manifestations. Genetic and environmental risk factors have been shown to be involved in the development of IIM. According to the European League Against Rheumatism/American College of Rheumatology classification criteria, IIM is divided into several clinical-serological subgroups: polymyositis (PM), dermatomyositis (DM; including adult and juvenile (JDM)), amyopathic DM (ADM), antisynthetase syndrome (ASS), inclusion body myositis (IBM), immune-mediated necrotizing myopathy (IMNM), hypomyopathic DM (HDM), cancer-associated myositis, and overlap myositis (OM). The identification of myositis-specific autoantibodies (MSAs) and myositis-associated antibodies (MAAs) has been shown to facilitate the identification of various IIM subgroups. Recently, patients with Coronavirus disease 2019 (COVID-19) are found to have similar IIM manifestations. In this mini-review, I collate current knowledge on IIM subgroups, MSAs/MAAs, and the correlation between IIMs and the COVID-19 pandemic, including but not limited to the presentation, diagnostic challenges, detection limitations, and currently proposed disease mechanisms. Early and prompt diagnosis of patients with different IIM subgroups will help avoid serious complications, such as rapidly progressive interstitial lung disease, and improve treatment outcomes and survival of IIM and COVID-19 patients.