免疫介导的坏死性肌病一例及其分型研究进展

A Single Case of Immune-Mediated Necrotizing Myopathy and Its Subtyping Progress

摘要: 目的：首先总结免疫介导的坏死性肌病(IMNM)的发病机制及其分型，其次总结该患儿的临床特点以及辅助检查，提高对该病的认识。此外免疫介导的坏死性肌病(IMNM)以肌酐激酶升高和组织学上散在坏死的肌纤维为特征，通常与抗信号识别颗粒(SRP)或3-羟基-3-甲基戊二酰辅酶A还原酶(HMGCR)的自身抗体有关。通常进展迅速，病情严重，严重的病例常出现不良临床反应和复发。抗B细胞疗法常用于难治/复发病例，其次可能对与抗SRP抗体相关的IMNM患者更为显著。抗3-羟基-3-甲基戊二酰辅酶A还原酶(HMGCR)阳性免疫介导的坏死性肌病(IMNM)常常由外源性物质诱发的，最常见的是他汀类药物，皮肤损害更常见。病理结果表明IMNMS的主要组织病理学表现为：肌纤维频繁坏死和再生，MHC-I在非坏死纤维中的可变表达和肌浆p62的恒定表达。在血清阴性的IMNM患者中，疾病可能伴随着癌症。治疗方面，利妥昔单抗或静脉注射免疫球蛋白等方法现在可以用于IMNM的治疗，而靶向治疗，如抗补体治疗，可能是难治性疾病患者的未来选择。

Abstract: OBJECTIVE: To firstly summarize the pathogenesis of immune-mediated necrotizing myopathy (IMNM) and its staging, and secondly to summarize the clinical features as well as the ancillary in-vestigations in this child to improve the understanding of the disease. In addition, im-mune-mediated necrotizing myopathy (IMNM) is characterized by elevated creatinine kinase and histologically scattered necrotic myofibers, usually associated with autoantibodies against signal recognition particles (SRP) or 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). Pro-gression is usually rapid and severe, with adverse clinical reactions and relapses often occurring in severe cases. Anti-B cell therapy is commonly used in refractory/relapsed cases and to a lesser ex-tent may be more significant in patients with IMNM associated with anti-SRP antibodies. An-ti-3-hydroxy-3- methylglutaryl coenzyme A reductase (HMGCR)-positive immune-mediated ne-crotizing myopathy (IMNM) is often induced by exogenous substances, most commonly statins, and skin damage is more common. Pathological findings suggest that the main histopathological mani-festations of IMNMS are: frequent necrosis and regeneration of myofibers, variable expression of MHC-I in non-necrotic fibers and constant expression of sarcoplasmic p62. In seronegative IMNM patients, the disease may be accompanied by cancer. For treatment, approaches such as rituximab or intravenous immunoglobulin are now available for IMNM, while targeted therapies, such as an-ti-complement therapy, may be a future option for patients with refractory disease.