Servicio de Reumatología, Hospital Universitario La Paz, Madrid, Spain.
Servicio de Reumatología, Hospital Universitario Doce de Octubre, Madrid, Spain.
Int J Rheum Dis. 2019 Aug;22(8):1393-1401. doi: 10.1111/1756-185X.13559. Epub 2019 Apr 10.
Inflammatory idiopathic myositis (IIM) comprises a heterogeneous group of systemic muscular diseases that can occur together with other connective tissue diseases (CTD), named overlap myositis (OM). The question of whether OM is a distinct entity still remains controversial.
The present study was conducted to assess the clinical and prognostic differences between patients diagnosed with OM, primary polymyositis (PM) and primary dermatomyositis (DM).
The study consists of a retrospective longitudinal and multicenter series of IIM patients. Patients were classified as OM, PM and DM. Overlap myositis was defined as patients fulfilling criteria for IIM plus criteria for other CTD (namely systemic sclerosis, systemic lupus erythematosus, mixed connective tissue disease, rheumatoid arthritis and primary Sjögren's syndrome).
A total of 342 patients were included (98 OM, 137 PM and 107 DM). Overlap myositis patients, in comparison with PM and DM, showed significant differences, with more extramuscular involvement, particularly more arthritis (66%, 34.6% and 48.1%, respectively), puffy fingers (49.5%, 11.1% and 24.3%), sclerodactyly (45.4%, 2.2% and 2%), dysphagia (41.8%, 18.2% and 26.4%), Raynaud phenomenon (65.3%, 16.9% and 19.8%), leucopenia (28.9%, 2.2% and 8.4%), thrombocytopenia (8.2%, 2.2% and 1.9%), interstitial lung disease (ILD) (48%, 35% and 30.8%), renal manifestations (13.4%, 3.7% and 1.9%), and more severe infections (41.3%, 26.7% and 21%). No significant differences were found in survival between groups in log rank test (P = 0.106). Multivariate adjusted survival analyses revealed a worse prognosis for severe infections, ILD and baseline elevation of acute phase reactants.
Overlap myositis stands out as a distinct entity as compared to PM and DM, featuring more extramuscular involvement and more severe infections. Close monitoring is recommended in this subset for early detection and treatment of possible complications.
特发性炎性肌病（IIM）由一组异质性全身肌肉疾病组成，可与其他结缔组织疾病（CTD）同时发生，称为重叠肌炎（OM）。OM 是否为一种独特的实体仍存在争议。
本研究旨在评估 OM、原发性多发性肌炎（PM）和原发性皮肌炎（DM）患者的临床和预后差异。
该研究是一项回顾性纵向多中心 IIM 患者系列研究。患者分为 OM、PM 和 DM。重叠肌炎的定义为符合 IIM 标准且符合其他 CTD 标准（即系统性硬化症、系统性红斑狼疮、混合性结缔组织病、类风湿关节炎和原发性干燥综合征）的患者。
共纳入 342 例患者（98 例 OM、137 例 PM 和 107 例 DM）。与 PM 和 DM 相比，重叠肌炎患者的肌肉外表现更为明显，特别是关节炎（66%、34.6%和 48.1%）、浮肿手指（49.5%、11.1%和 24.3%）、硬皮病（45.4%、2.2%和 2%）、吞咽困难（41.8%、18.2%和 26.4%）、雷诺现象（65.3%、16.9%和 19.8%）、白细胞减少症（28.9%、2.2%和 8.4%）、血小板减少症（8.2%、2.2%和 1.9%）、间质性肺病（ILD）（48%、35%和 30.8%）、肾脏表现（13.4%、3.7%和 1.9%）和更严重的感染（41.3%、26.7%和 21%）。对数秩检验显示各组之间的生存无显著差异（P=0.106）。多变量调整生存分析显示严重感染、ILD 和基线急性期反应物升高与预后较差相关。
与 PM 和 DM 相比，重叠肌炎是一种独特的实体，其肌肉外表现更为明显，且感染更为严重。对于这一亚组患者，建议进行密切监测，以早期发现和治疗可能出现的并发症。
