Immune-mediated necrotising myopathy (IMNM) is a recently described entity. We describe a cohort of South Australian IMNM patients in order to define the spectrum of disease, characterise features that distinguish IMNM from other idiopathic inflammatory myopathy (IIM) subtypes and identify factors associated with clinically severe disease. Subjects were identified from the South Australian Myositis Database (SAMD), a histologically defined registry. Consecutive muscle sections from patients with IMNM (n = 62), other forms of IIM (n = 60) and histologically normal muscle (n = 17) were stained using immunohistochemistry and graded. Clinical information was collected from the SAMD and through retrospective chart review. IMNM patients displayed clinical and histological heterogeneity. While most (67%) were profoundly weak at presentation, 24% exhibited mild to moderate weakness and 9% had normal power. Histological myonecrosis ranged from minor to florid. The amount of myofibre complement deposition was closely associated with clinical severity. Patients of Aboriginal and Torres Strait Islander heritage and those with anti-SRP autoantibodies present with a severe phenotype. Despite intense immunotherapy, few IMNM patients recovered full power at one year follow up. The identification of clinical, serological and histological features which are associated with severe forms of the disease may have diagnostic and therapeutic utility.

中文翻译：

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免疫介导的坏死性肌病的临床和组织学特征：一项多中心的南澳大利亚队列研究

免疫介导的坏死性肌病 (IMNM) 是最近描述的实体。我们描述了一组南澳大利亚 IMNM 患者，以定义疾病谱，表征将 IMNM 与其他特发性炎症性肌病 (IIM) 亚型区分开来的特征，并确定与临床严重疾病相关的因素。受试者是从南澳大利亚肌炎数据库 (SAMD) 中确定的，这是一个组织学定义的注册表。来自 IMNM (n = 62)、其他形式的 IIM (n = 60) 和组织学正常肌肉 (n = 17) 的连续肌肉切片使用免疫组织化学染色并分级。临床信息是从 SAMD 和通过回顾性图表审查收集的。IMNM 患者表现出临床和组织学异质性。虽然大多数 (67%) 在演示时非常虚弱，24% 的人表现出轻度至中度的无力，9% 的人有正常的力量。组织学肌坏死范围从轻微到严重。肌纤维补体沉积量与临床严重程度密切相关。原住民和托雷斯海峡岛民传统患者以及具有抗 SRP 自身抗体的患者表现出严重的表型。尽管进行了强烈的免疫治疗，但很少有 IMNM 患者在一年的随访中完全恢复。与严重形式的疾病相关的临床、血清学和组织学特征的鉴定可能具有诊断和治疗效用。原住民和托雷斯海峡岛民传统患者以及具有抗 SRP 自身抗体的患者表现出严重的表型。尽管进行了强烈的免疫治疗，但很少有 IMNM 患者在一年的随访中完全恢复。与严重形式的疾病相关的临床、血清学和组织学特征的鉴定可能具有诊断和治疗效用。原住民和托雷斯海峡岛民传统患者以及具有抗 SRP 自身抗体的患者表现出严重的表型。尽管进行了强烈的免疫治疗，但很少有 IMNM 患者在一年的随访中完全恢复。与严重形式的疾病相关的临床、血清学和组织学特征的鉴定可能具有诊断和治疗效用。