Muruganandam Maheswari, Iqbal Ahsan, Akpan Eyerusalem B, Dolomisiewicz Anthony C, Waters Yvonne M, Emil N Suzanne, Nunez Sharon E, McElwee Matthew K, O'Sullivan Frank X, Fields Roderick A, Sibbitt Wilmer L
Department of Internal Medicine, Division of Rheumatology and School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM.
Department of Internal Medicine, Division of Rheumatology and Immunology, University of Nebraska Medical Center, Nebraska Medical Center, Omaha, NE, USA.
Rheumatology (Oxford). 2022 Nov 28;61(12):4855-4862. doi: 10.1093/rheumatology/keac198.
Statin-associated immune-mediated necrotizing myopathy (IMNM) and idiopathic inflammatory myositis (IIM) are myopathies with overlapping features. This study compared the manifestations of IMNM to IIM in Native Americans.
Twenty-one Native American patients with inflammatory myopathy (IM) were characterized as to diabetes mellitus, hyperlipidaemia, statin exposure, myopathy diagnosis, muscle histology, autoimmune and myositis-specific autoantibodies, therapy and outcome.
IM consisted of 52.4% IMNM, 42.9% IIM and 4.8% metabolic myopathy. IMNM vs IIM patients were older [61.6 years (s.d. 9.8) vs 39.8 (14.3)], diabetes mellitus (100% vs 55.6%), hyperlipidaemia (100% vs 33.3%), statin-exposure (100% vs 22.2%), creatine kinase [CK; 11 780 IU (s.d. 7064) vs 1707 (1658)], anti-3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) antibodies (85.7% vs 11.1%) and necrotizing IM (81.8% vs 11.1%), but shorter disease duration [26.2 months (s.d. 395) vs 78.4 (47.9)], RP (9.1% vs 55.6%), cutaneous manifestations (0% vs 55.6%), ANA (18.2% vs 66.7%) or any autoantibody (18.2% vs 88.9%) (all P < 0.05). MRI abnormalities, histologic IM, myositis-specific autoantibodies, pulmonary hypertension, oesophageal dysfunction, interstitial lung disease, disability and persistently elevated CK were similar. IMNM vs IIM was treated more with IVIG (72.7% vs 11.1%; P = 0.009) and less with antimetabolites (45.5% vs 88.9%; P = 0.05) and rituximab (18.2% vs 55.6%; P = 0.09).
IMNM may occur in Native Americans and is associated with diabetes mellitus, hyperlipidaemia, statin use and older age and is characterized by marked CK elevation, necrotizing myopathy and anti-HMGCR antibodies with few cutaneous or vascular manifestations.
他汀类药物相关免疫介导坏死性肌病（IMNM）和特发性炎性肌病（IIM）是具有重叠特征的肌病。本研究比较了美洲原住民中IMNM与IIM的表现。
对21例患有炎性肌病（IM）的美洲原住民患者进行了糖尿病、高脂血症、他汀类药物暴露、肌病诊断、肌肉组织学、自身免疫和肌炎特异性自身抗体、治疗及预后等方面的特征分析。
IM包括52.4%的IMNM、42.9%的IIM和4.8%的代谢性肌病。IMNM患者与IIM患者相比年龄更大[61.6岁（标准差9.8）对39.8岁（14.3）]，糖尿病患病率更高（100%对55.6%），高脂血症患病率更高（100%对33.3%），他汀类药物暴露率更高（100%对22.2%），肌酸激酶[CK；11780 IU（标准差7064）对1707（1658）]，抗3-羟基-3-甲基戊二酰辅酶A还原酶（HMGCR）抗体阳性率更高（85.7%对11.1%），坏死性IM比例更高（81.8%对11.1%），但病程更短[26.2个月（标准差395）对78.4个月（47.9）]，雷诺现象（RP）发生率更低（9.1%对55.6%），皮肤表现更少（0%对55.6%），抗核抗体（ANA）阳性率更低（18.2%对66.7%）或任何自身抗体阳性率更低（18.2%对88.9%）（所有P<0.05）。MRI异常、组织学IM、肌炎特异性自身抗体、肺动脉高压、食管功能障碍、间质性肺病、残疾及CK持续升高情况相似。IMNM与IIM相比，接受静脉注射免疫球蛋白（IVIG）治疗的比例更高（72.7%对11.1%；P=0.009），接受抗代谢药物治疗的比例更低（45.5%对88.9%；P=0.05），接受利妥昔单抗治疗的比例更低（18.2%对55.6%；P=0.09）。
IMNM可能发生在美洲原住民中，与糖尿病、高脂血症、他汀类药物使用及年龄较大有关，其特征为CK显著升高、坏死性肌病及抗HMGCR抗体，皮肤或血管表现较少。
