The Alfred Hospital and Monash University, Melbourne, Victoria, Australia.
St. Vincent's Hospital Melbourne, Melbourne, Victoria, Australia.
Arthritis Care Res (Hoboken). 2021 May;73(5):732-741. doi: 10.1002/acr.24167. Epub 2021 Apr 3.
To describe the clinical characteristics and outcomes of systemic sclerosis-mixed connective tissue disease (SSc-MCTD) and SSc overlap syndrome.
We included patients from the Australian Scleroderma Cohort Study who met American College of Rheumatology/European Alliance of Associations for Rheumatology criteria for SSc. Three mutually exclusive groups were created: SSc-MCTD, SSc overlap, and SSc only. Univariate comparison of clinical features was performed by analysis of variance or chi-square test. Survival analysis was performed using Kaplan-Meier (KM) curves and Cox proportional hazards regression models.
Of 1,728 patients, 97 (5.6%) had SSc-MCTD, and 126 (7.3%) had SSc overlap. Those with MCTD-SSc were more commonly Asian (18.3% versus 10.1% in SSc overlap, and 3.6% in SSc only; P < 0.0001) and younger at disease onset (38.4 years versus 46.5 or 46.8 years, P < 0.0001). Those with SSc-MCTD or SSc overlap were more likely to have limited cutaneous SSc. All 3 groups had similar frequency of interstitial lung disease (ILD), although pulmonary arterial hypertension (PAH) was less common in SSc overlap. Synovitis and myositis were more common in SSc overlap and SSc-MCTD than in SSc only. KM curves showed better survival in SSc-MCTD than SSc overlap or SSc only (P = 0.011), but this was not significant after adjustment for sex and age at disease onset. SSc-specific antibodies were survival prognostic markers, with antinuclear antibody centromere or anti-RNP conferring better survival than anti-Scl-70 or anti-RNA polymerase III (P = 0.005). Patients with SSc-MCTD and SSc overlap had lower mortality following diagnosis of ILD and PAH than patients with SSc only.
This study provides insights into the clinical characteristics of patients with SSc-MCTD, SSc overlap, and SSc only and shows that anti-RNP antibodies are associated with better survival than anti-Scl-70 and anti-RNA polymerase III antibodies.
描述系统性硬化症-混合性结缔组织病（SSc-MCTD）和重叠性系统性硬化症的临床特征和结局。
我们纳入了符合美国风湿病学会/欧洲抗风湿病联盟 SSc 诊断标准的澳大利亚硬皮病队列研究中的患者。创建了三个互斥的组：SSc-MCTD、重叠性 SSc 和单纯 SSc。采用方差分析或卡方检验进行临床特征的单变量比较。采用 Kaplan-Meier（KM）曲线和 Cox 比例风险回归模型进行生存分析。
在 1728 例患者中，97 例（5.6%）为 SSc-MCTD，126 例（7.3%）为重叠性 SSc。MCTD-SSc 患者更常见于亚洲人（18.3%与重叠性 SSc 中的 10.1%和单纯 SSc 中的 3.6%相比，P＜0.0001），且发病年龄更小（38.4 岁与 46.5 岁或 46.8 岁相比，P＜0.0001）。SSc-MCTD 或重叠性 SSc 患者更可能为局限性皮肤型 SSc。所有 3 组间间质性肺病（ILD）的发生率相似，尽管重叠性 SSc 中肺动脉高压（PAH）较少见。关节炎和肌炎在重叠性 SSc 和 SSc-MCTD 中比单纯 SSc 更常见。KM 曲线显示 SSc-MCTD 的生存优于重叠性 SSc 或单纯 SSc（P=0.011），但在校正发病年龄和性别后无统计学意义。抗核抗体着丝粒或抗 RNP 等 SSc 特异性抗体是生存预后标志物，与抗 Scl-70 或抗 RNA 聚合酶 III 相比，抗核抗体着丝粒或抗 RNP 抗体的生存预后更好（P=0.005）。与单纯 SSc 患者相比，SSc-MCTD 和重叠性 SSc 患者在ILD 和 PAH 诊断后死亡率更低。
本研究深入了解了 SSc-MCTD、重叠性 SSc 和单纯 SSc 患者的临床特征，并表明抗 RNP 抗体与抗 Scl-70 和抗 RNA 聚合酶 III 抗体相比，与更好的生存相关。
