摘要目的:分析抗黑素瘤分化相关基因5（MDA5）抗体阳性皮肌炎（MDA5-DM）临床特征，为早期诊断和早期治疗提供依据。方法:入组2019年3月至2021年6月南京医科大学炎性肌病相关肺间质病变队列MDA5-DM患者272例，以76例抗合成酶抗体综合征（ASS）患者为对照，分析其临床特征及肺间质病变发生情况。对于正态分布且方差齐的两组独立样本采用 t检验比较均数，非正态分布计量资料采用Mann-Whitney U检验比较，对二分类变量资料使用 χ2检验或Fisher确切概率法进行比较。 结果:在272例MDA5-DM患者中，88.6%（241/272）患者发生间质性肺疾病（ILD），33.8%（92/272）患者出现快速进展性ILD（RP-ILD）。MDA5-DM患者6个月全因病死率为16.9%（46/272），伴发RP-ILD患者6个月全因病死率高达47.8%（44/92）。与ASS患者相比，MDA5-DM患者男性和关节炎比例、Gottron征、向阳疹、V字征、甲周红斑和皮肤溃疡比例明显高于ASS组（ P<0.05），ALT、AST和铁蛋白显著升高（ P<0.05）。与非RP-ILD患者相比，RP-ILD患者男性比例[35.9%（33/92）和23.3%（42/180）， χ2=4.79， P=0.029]、LDH[387（276，547）U/L和310（245，400）U/L， Z=-3.67， P<0.001]、ESR[45.5（29.25，63.25）mm/1 h和31.2（20，51）mm/1 h， Z=-3.71， P<0.001]、CRP[10.9（4.1，25.2）mg/L和4.54（2.58，9.08）mg/L， Z=-4.97， P<0.001]和铁蛋白水平[1 340（650，2 000）ng/ml和556（203，1 186）ng/ml， Z=-4.40， P<0.001]、抗Ro52抗体和抗MDA5抗体双阳性的比例[87.0%（80/92）和52.2%（94/180）， χ2=31.87， P<0.001]显著增加。 结论:MDA5-DM患者易出现RP-ILD，预后差。

abstractsObjective:To analyze the clinical features of MDA5 antibody positive dermatomyositis (MDA5-DM) and to provide evidence for early diagnosis and treatment.Methods:From March 2019 to June 2021, 272 patients with anti-MDA5-DM from the Nanjing Medical University myositis-associated interstitial lung disease cohort were enrolled, with 76 patients with anti-synthetase syndrome (ASS) as the control group. The clinical characteristics and the occurrence of interstitial lung disease were analyzed. T-test was used for normally distributed and variance-homogeneous independent samples, Mann-Whitney U test for non-normally distributed data, and chi-square test or Fisher′s exact test for dichotomous variables. Results:Among the 272 anti-MDA5-DM patients, 88.6% (241/272) developed interstitial lung disease (ILD), and 33.8% (92/272) developed rapidly progressive ILD (RP-ILD). The six-month all-cause mortality rate of anti-MDA5-DM patients was 16.9% (46/272), and it was as high as 47.8% (44/92) for those with RP-ILD. Compared with ASS patients, anti-MDA5-DM patients had a significantly higher proportion of males, arthritis, Gottron's sign, heliotrope rash, V-sign, periungual erythema, and skin ulcers ( P<0.05). The levels of ALT, AST, and ferritin were significantly increased ( P<0.05). Compared with non-RP-ILD patients, RP-ILD patients had a significantly higher proportion of males [35.9%(33/92) vs. 23.3%(42/180), χ2=4.79, P=0.029], higher levels of LDH [387 (276, 547) U/L vs. 310 (245, 400) U/L, Z=-3.67, P<0.001], ESR [45.5 (29.25, 63.25) mm/1 h vs. 31.2 (20, 51) mm/1 h, Z=-3.71, P<0.001], CRP [10.9 (4.1, 25.2) mg/L vs. 4.54 (2.58, 9.08) mg/L, Z=-4.97, P<0.001], ferritin [1 340 (650, 2 000) ng/ml vs. 556 (203, 1 186) ng/ml, Z=-4.40, P<0.001], and a higher proportion of anti-Ro52 antibody and anti-MDA5 antibody co-positivity [87.0%(80/92) vs. 52.2%(94/180), χ2=31.87, P<0.001]. Conclusion:Anti-MDA5-DM patients are prone to develop RP-ILD and have poor prognosis.