摘要目的:探讨抗黑色素瘤分化相关蛋白5（MDA5）抗体阳性皮肌炎（DM）合并纵隔气肿的临床特征。方法:收集2017年3月至2019年12月宁波市第一医院抗MDA5抗体阳性DM合并或不合并纵隔气肿患者的临床资料，复习国内外文献并与之比较。计量资料采用 t检验或Mann-Whitney U检验，计数资料采用 χ2检验或Fisher确切概率法，Logistic回归分析抗MDA5抗体阳性DM合并纵隔气肿的危险因素。 结果:该院共收治有12例抗MDA5抗体阳性DM不合并纵隔气肿者，1例抗MDA5抗体阳性DM合并纵隔气肿者，结合文献复习资料详细的16例抗MDA5抗体阳性DM合并纵隔气肿者，2组间比较，纵隔气肿组血清铁蛋白（SF）水平[991.6（548.5，2875.1）ng/ml与355（143.5，395）ng/ml， Z=-2.506， P=0.012]、快速进展性肺间质病变（RPILD）发生率（76.5%与16.7%， χ2=10.076， P=0.002）高于非纵隔气肿组。进一步Logistic回归分析并未发现男性[ OR=0.192，95% CI（0.009,4.125）， P=0.291]、SF[ OR=1.002，95% CI（0.998，1.006）， P=0.279）、RPILD（ OR=0.084，95% CI（0.003，2.178）， P=0.136）、临床无肌病性皮肌炎（CADM）（ OR=0.258，95% CI（0.009，7.419）， P=0.429]是抗MDA5抗体阳性DM合并纵隔气肿的危险因素。 结论:抗MDA5抗体阳性DM患者中，SF水平高、肺间质病变进展迅速的患者易合并纵隔气肿。

abstractsObjective:To investigate the clinical characteristics of dermatomyositis (DM) patients with positive anti-melanoma differentiation-associated protein 5 (MDA5) antibody-complicated with pneumomediastinum.Methods:Clinical data of patients with anti-MDA5 antibody-positive DM with or without pneumomediastinum from March 2017 to December 2019 in Ningbo First Hospital were collected and analyzed. The international literature were reviewed and compared. T-test or Mann-Whitney U test was used for measurement data, chi-square test or Fisher exact probability was used for count data. Logistic regression analysis was used to analyze the risk factors for anti-MDA5 antibody-positive DM with pneumomediastinum. Results:Twelve DM patients with -positive anti-MDA5 antibody without pneumomediastinum, and 1 DM patient with positive anti-MDA5 antibody-complicated with pneumomediastinum. Pooling with literature review, 16 DM patients with positive anti-MDA5 antibody-complicated with pneumomediastinum were compared. It was found that the serum ferritin (SF) level [991.6(548.5, 2875.1) ng/ml vs 355 (143.5, 395) ng/ml, Z=-2.506, P=0.012] and the rate of rapid progressive pulmonary interstitial disease (RPILD) in the pneumo-mediastinum group [76.5% vs 16.7%, χ2=10.076, P=0.002] were significantly higher than those in the non-pneumome-diastinum group. Further Logi-stic regression analysis did not show male gender [ OR=0.192, 95% CI(0.009, 4.125), P=0.291]; SF [ OR=1.002, 95% CI(0.998, 1.006), P=0.279]; RPILD[ OR=0.084, 95% CI(0.003, 2.178), P=0.136]; CADM[ OR=0.258, 95% CI(0.009, 7.419), P=0.429] was risk factor for pneumomediastinum. Conclusion:DM patients with positive anti-MDA5 antibody and high seral SF level and rapid progression of pulmonary interstitial disease are more likely to complicate with pneumomediastinum.