Abstract: Background　Concurrent interstitial lung disease（ILD）in patients with polymyositis（PM）and dermatomyositis（DM）is a major cause of death with a fatality rate that exceeds 50%.However，there are currently few domestic studies on the clinical characteristics and related influencing factors of PM/DM combined with ILD（PM/DM-ILD） with different results，and there is still no valid evidence to confirm which factors are related to the occurrence of PM/DM-ILD.Objective　To explore the clinical characteristics of PM/DM-ILD and its influencing factors.Methods　A total of 119 patients with PM/DM who were treated in the Affiliated Hospital of North Sichuan Medical College from January 1，2014 to June 30，2018 were selected as subjects and divided into ILD group and non-interstitial lung disease（NILD）group.The general data，clinical symptoms，laboratory parameters，results of lung high-resolution CT（HRCT）and prognosis of the two groups were compared.Stepwise Logistic regression was used to analyze the influencing factors of PM/DM-ILD.Results　The age，the first episode of arthritis，the first episode of respiratory symtom，mechanic's hand，Reynolds phenomenon，dry cough，expectoration，post-exercise shortness of breath，fever，incidence of arthritis，erythrocyte sedimentation rate（ESR），globulin（GLOB） level，positive rate of anti-Jo-1 antibody of patients in ILD group were higher than those of patients in the NILD group，while the first episode of myasthenia，creatine kinase（CK），CK/glutamic-oxalacetic transaminase（AST），albumin（ALB） level of patients in ILD group were lower than those of patients in NILD group（P<0.05）．Lung HRCT manifestations of 60 patients of the ILD group were mainly stripe shadow（68.3%，41/60），patchy shadow（68.3%，41/60），reticulate shadow（45.0%，27/60），ground glass opacity shadow（31.7%，19/60），cloud flocculent shadow（15.0%，9/60），and honeycomb shadow（10.0%，6/60），which could be seen alone or simultaneously.In NILD group，25.4%（15/59） of lung HRCT also showed a small amount of stripe shadow，patchy shadow and ground glass opacity shadow while the lesion location，distribution range and lesion degree did not meet the imaging diagnostic criteria of ILD，and most of them were old changes of previous diseases.The results of stepwise Logistic regression analysis showed that age，dry cough，post-exercise shortness of breath，arthritis，GLOB and anti-Jo-1 antibody were influencing factors of PM/DM-ILD（P<0.05）．The repetitive hospitalization rate and the rate of repetitive hospitalization caused by pulmonary infection in ILD group were higher than those in NILD group（χ2=5.275，P=0.022； P=0.010）．There was no significant difference in the treatment effects between the two groups（χ2=0.192，P=0.909）．Conclusion　Advanced age，dry cough，arthritis，post-exercise shortness of breath，positive anti-Jo-1 antibody in serum and elevated GLOB level are risk factors for PM/DM-ILD.The lung function and HRCT changes of elderly patients with above symptoms and related serological results need to be closely monitored.

Key words: Polymyositis；Dermatomyositis；Lung disease, interstitial；Clinical characteristics；Root cause analysis

摘要： 背景　多发性肌炎（PM）/皮肌炎（DM）患者合并间质性肺疾病（ILD）是PM/DM主要致死因素，致死率在50%以上。目前国内对PM/DM合并ILD（PM/DM-ILD）临床特征及其影响因素的研究较少，且研究结果各不相同，尚缺乏有效证据证实哪些因素与PM/DM-ILD的发生有关。目的　探讨PM/DM-ILD患者的临床特征及其影响因素。方法　选取2014-01-01至2018-06-30于川北医学院附属医院诊治的119例PM/DM患者为研究对象，将其分为ILD组与非间质性肺疾病（NILD）组。比较两组一般情况、临床表现、实验室指标、肺部高分辨率CT（HRCT）结果及预后情况。采用逐步Logistic回归分析PM/DM-ILD的影响因素。结果　ILD组患者年龄，关节炎首发、呼吸道症状首发、技工手、雷诺现象、干咳、咳痰、活动后气促、发热、关节炎发生率，红细胞沉降率（ESR）、球蛋白（GLOB）水平，抗Jo-1抗体阳性率高于NILD组，肌无力首发、肌酸激酶（CK）、CK/天冬氨酸氨基转移酶（AST）、清蛋白（ALB）水平低于NILD组（P<0.05）。ILD组中60例患者肺部HRCT以条索影（68.3%，41/60）、斑片影（68.3%，41/60）、网格状影（45.0%，27/60）、磨玻璃样（31.7%，19/60）、云絮状影（15.0%，9/60）、蜂窝状影（10.0%，6/60）等表现多见，可单独或同时出现；NILD组25.4%（15/59）的肺部HRCT也会出现少量条索影、斑片影、磨玻璃影等，但其病变部位、分布范围和病变程度均不满足ILD的影像学诊断标准，多属既往疾病的陈旧性改变。逐步Logistic回归分析结果显示，年龄、干咳、活动后气促、关节炎、GLOB、抗Jo-1抗体水平是PM/DM-ILD的影响因素（P<0.05）。ILD组患者重复住院率（χ2=5.275，P=0.022）、肺部感染致重复住院率（P=0.010）高于NILD组。两组治疗效果比较，差异无统计学意义（χ2=0.192，P=0.909）。结论　年龄大，干咳、关节炎、活动后气促症状，血清抗Jo-1抗体阳性，GLOB水平升高是PM/DM-ILD发生的危险因素，对表现上述症状及血清学结果的高龄患者需密切检测其肺功能及肺部HRCT的改变。

关键词: 多发性肌炎；皮肌炎；肺疾病, 间质性；临床特征；影响因素分析