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

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