Unit of Rheumatology, Department of Precision and Regenerative Medicine, Area Jonica (DiMePRe-J), University of Bari, Italy.
Unit of Human Anatomy and Histology, Department of Translational Biomedicine and Neuroscience "DiBraiN", University of Bari, Italy.
Clin Exp Rheumatol. 2024 Feb;42(2):288-294. doi: 10.55563/clinexprheumatol/kgpnbq. Epub 2024 Mar 14.
To characterise clinical amyopathic dermatomyositis (CADM) from a clinical, histological, and prognostic perspective.
We retrospectively recorded data from our DM cohort. Patients were categorised into three groups: classic DM, hypomyopathic DM (HDM), characterised by normal muscle strength and evidence of muscle involvement in laboratory tests and/or instrumental examinations and CADM, featured by normal muscle strength and unremarkable findings in both laboratory tests and instrumental examinations. Available muscle biopsies from each group were also compared.
Our cohort included 63 DM (69.2%), 12 HDM (13.2%) and 16 CADM (17.6%) patients. Compared to DM, CADM patients were younger at onset and diagnosis (45.5±17 vs. 57±18, and 46±17 vs. 58±18 years, respectively; p<0.05). They were more likely to test positive for anti-MDA5 (37.5% vs. 4.8%) and anti- TIF1-γ (31.3% vs. 6.3%), had a higher incidence of arthritis (37.5% vs. 12.6%) and interstitial lung disease (ILD) (43.8% vs. 15.9%) (all comparisons with p<0.05). Muscle biopsies were available for 44 DM, 7 CADM, and 11 HDM patients, revealing similar sarcolemma MHC-I expression rates. Five-year survival rates were comparable across groups (DM: 74.6%, CADM: 75%, HDM: 83.3%). Cox analysis indicated the main mortality predictors in overall cohort were ILD (HR: 3.57, CI: 1.11-11.5) and cancer (HR: 3.67, CI: 1.17-11.5), not CADM (HR: 1.46, CI: 0.33-6.68).
CADM patients differ in disease onset, autoantibody profiles, joint and lung involvement. While laboratory and instrumental tests have not shown muscle involvement in CADM, many muscle biopsies have shown MHC-I overexpression.
从临床、组织学和预后的角度描述临床无肌病性皮肌炎（CADM）。
我们回顾性地记录了我们的 DM 队列中的数据。患者分为三组：经典 DM、低肌病性 DM（HDM），其特征为肌肉力量正常，实验室检查和/或仪器检查显示有肌肉受累，以及 CADM，其特征为肌肉力量正常，实验室检查和仪器检查均无明显异常。还比较了每组现有的肌肉活检。
我们的队列包括 63 例 DM（69.2%）、12 例 HDM（13.2%）和 16 例 CADM（17.6%）患者。与 DM 相比，CADM 患者的发病和诊断年龄更小（分别为 45.5±17 岁和 57±18 岁，以及 46±17 岁和 58±18 岁；p<0.05）。他们更有可能检测到抗 MDA5（37.5% vs. 4.8%）和抗 TIF1-γ（31.3% vs. 6.3%）阳性，关节炎（37.5% vs. 12.6%）和间质性肺病（ILD）（43.8% vs. 15.9%）发生率更高（所有比较均 p<0.05）。有 44 例 DM、7 例 CADM 和 11 例 HDM 患者进行了肌肉活检，显示相似的肌膜 MHC-I 表达率。各组 5 年生存率相似（DM：74.6%，CADM：75%，HDM：83.3%）。Cox 分析表明，总体队列中主要的死亡率预测因素是ILD（HR：3.57，CI：1.11-11.5）和癌症（HR：3.67，CI：1.17-11.5），而不是 CADM（HR：1.46，CI：0.33-6.68）。
CADM 患者在疾病发作、自身抗体谱、关节和肺部受累方面存在差异。虽然实验室和仪器检查未显示 CADM 有肌肉受累，但许多肌肉活检显示 MHC-I 过度表达。
