Mutoh Tomoyuki, Takahashi Mikihiro, Satake Hiroyuki, Daikoku Kensuke, Fujii Hiroshi
Department of Rheumatology, Osaki Citizen Hospital, 3-8-1 Furukawa Honami, Osaki, Miyagi, 989 - 6183, Japan.
Department of Rheumatology, Tohoku University Hospital, Sendai, Miyagi, Japan.
Clin Rheumatol. 2025 Apr 16. doi: 10.1007/s10067-025-07439-3.
Idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of autoimmune diseases characterized primarily by muscle inflammation. Anti-mitochondrial antibodies (AMA) are typically associated with primary biliary cholangitis; however, they have also been linked to a rare subgroup of IIMs, namely "AMA-positive myositis," marked by a chronic disease course and muscle weakness, particularly affecting the paravertebral muscles, alongside muscle atrophy and cardiopulmonary complications. We report the case of a 40-year-old woman diagnosed with AMA-positive myositis, predominantly involving axial myopathy complicated by multiple arrhythmias and biopsy-proven focal segmental glomerulosclerosis with mitochondrial abnormalities on electron microscopy. The patient presented with progressive back pain and palpitations over a 3-month period. Although high-dose glucocorticoids and intravenous cyclophosphamide improved the axial myopathy and proteinuria, the cardiac condition remained unstable, necessitating permanent pacemaker implantation for persistent sinus dysfunction and radiofrequency catheter ablation for worsening atrial fibrillation (Af). Our literature review focusing on cardiac involvement in AMA-positive myositis revealed tachyarrhythmia was the most common (87.7%), particularly Af (55.4%), followed by cardiomyopathy (74.2%), myocarditis (43.2%), and bradyarrhythmia (40.0%). Arrhythmias and/or cardiac function deteriorated in 41.7% of patients treated with immunosuppressants and in 66.7% of patients treated without immunosuppressants, respectively. Furthermore, in the treated group, more patients with worsened cardiac lesions required additional electronic devices compared to those without (53.3% vs. 4.8%). Early detection and adequate management of cardiac complications in AMA-positive myositis are critical to prevent irreversible myocardial damage and fatal outcomes. In addition to cardiac complications, concomitant renal involvement associated with AMA-positive myositis may be also considered.
特发性炎性肌病（IIMs）是一组异质性自身免疫性疾病，主要特征为肌肉炎症。抗线粒体抗体（AMA）通常与原发性胆汁性胆管炎相关；然而，它们也与IIMs的一个罕见亚组有关，即“AMA阳性肌炎”，其特点是病程慢性、肌肉无力，尤其影响椎旁肌，伴有肌肉萎缩和心肺并发症。我们报告了一例40岁女性诊断为AMA阳性肌炎的病例，主要累及轴索性肌病，并发多种心律失常，活检证实为局灶节段性肾小球硬化，电镜下可见线粒体异常。患者在3个月内出现进行性背痛和心悸。尽管大剂量糖皮质激素和静脉注射环磷酰胺改善了轴索性肌病和蛋白尿，但心脏状况仍不稳定，因持续性窦性功能障碍需要植入永久性起搏器，因房颤（Af）恶化需要进行射频导管消融。我们对AMA阳性肌炎心脏受累情况的文献综述显示，快速性心律失常最为常见（87.7%），尤其是Af（55.4%），其次是心肌病（74.2%）、心肌炎（43.2%）和缓慢性心律失常（40.0%）。接受免疫抑制剂治疗的患者中，41.7%出现心律失常和/或心脏功能恶化，未接受免疫抑制剂治疗的患者中这一比例为66.7%。此外，在治疗组中，与未出现心脏病变恶化的患者相比，更多心脏病变恶化的患者需要额外的电子设备（53.3%对4.8%）。早期发现和适当处理AMA阳性肌炎的心脏并发症对于预防不可逆的心肌损伤和致命后果至关重要。除了心脏并发症外，还可能需要考虑AMA阳性肌炎合并的肾脏受累情况。
