摘要目的:回顾性分析老年抗黑色素瘤分化相关基因(MDA5)抗体阳性皮肌炎患者的临床特征。方法:收集2016年5月至2019年12月我院收治的抗MDA5抗体阳性皮肌炎患者62例，并根据年龄将其分为老年组(≥60岁，17例)和非老年组(<60岁，45例)。对两组患者的临床表现、实验室检查、治疗情况及预后等资料进行统计分析。结果:本研究共纳入62例抗MDA5抗体阳性皮肌炎患者，老年患者17例(27.4%)，年龄为(65.5±5.3)岁，非老年患者45例(72.6%)，年龄为(46.5±8.4)岁。与非老年患者相比，老年患者的病程更短[(1.6±1.0)月比(3.7±3.3)月， t＝3.883， P<0.001]，伴有劳力性呼吸困难以及合并抗Ro-52抗体阳性的比例更高[分别为(15/17，88.2%)比(26/45，57.8%)， χ2＝5.11， P＝0.024和(15/17，88.2%)比(26/45，57.8%)， χ2＝5.11， P＝0.024]，且病死率显著增高[(12/17，70.6%)比(8/45，17.8%)， χ2＝15.748， P<0.001]；伴有Heliotrope征的老年患者少于非老年患者[(9/17，41.2%)比(38/45，57.8%)， χ2＝5.07， P＝0.024]。 结论:老年抗MDA5抗体阳性皮肌炎具有独特临床表型，其起病急、皮疹不典型、肺部病变重，治疗难度大，预后更差。

abstractsObjective:To retrospectively analyze the clinical characteristics of elderly patients with anti-MDA5 antibody-positive dermatomyositis.Methods:Data of 62 patients with anti-MDA5 antibody-positive dermatomyositis admitted to Second Xiangya Hospital from May 2016 to December 2019 were collected and patients were divided into an elderly group(≥60 years old, 17 cases)and a non-elderly group(<60 years old, 45 cases). The clinical manifestations, laboratory test resuls, treatment and prognosis of the patients in both groups were statistically analyzed.Results:A total of 62 patients with anti-MDA5 antibody-positive dermatomyositis were included in this study, including 17 elderly patients(27.4%)with an average age of(65.5±5.3)years and 45 non-elderly patients(72.6%)with an average age of(46.5±8.4)years.Compared with non-elderly patients, older patients had a shorter disease duration[(1.6±1.0)months vs.(3.7±3.3)months, t=3.883, P<0.001], a higher proportion of patients with exertional dyspnea(15/17 or 88.2% vs.26/45 or 57.8%, χ2=5.11, P=0.024)and with combined positive anti-Ro-52 antibodies(15/17 or 88.2% vs.26/45 or 57.8%, χ2=5.11, P=0.024), and a higher mortality rate[(12/17 or 70.6%) vs.(8/45 or 17.8%, χ2=15.748, P<0.001)]. In contrast, fewer elderly patients than non-elderly patients had the Heliotrope's sign(9/17 or 41.2% vs.38/45 or 57.8%), χ2=5.07, P=0.024). Conclusions:Elderly patients with anti-MDA5 antibody-positive dermatomyositis have a unique clinical phenotype with an acute onset, atypical rashes, severe pulmonary lesions, making treatment difficult, and have a poor prognosis.