Analysis Of Survival And Risk Factors Associated With Survival And Interstitial Lung Disease In Patients With Idiopathic Inflammatory Myopathy

Objective:1.To study the independent risk factors for IIM-ILD by retrospectively analyzing and comparing the clinical characteristics of ILD and non-ILD patients with idiopathic inflammatory myopathy(IIM).2.To explore the survival rates and prognosis in different subgroups and the overall of IIM,as well as the independent risk factors related to survival via cohort follow-up.Methods:The medical records of 303 IIM patients who admitted to Rheumatology and Immunology Department of Tongji hospital affiliated to Tongji Medical College of Huazhong University of science and technology from January 2012 to December 2018 were retrospectively collected.We gathered the related clinical data(including demographic information,clinical manifestations,laboratory parameters and therapy modalities)through browsing the electronic medical records system and obtained the outcome of patients mainly through follow-up.Patients were divided into ILD group and non-ILD group according to the presence or absence of interstitial lung disease and were divided into survival group and death group on the basis of the survival condition at the end of follow-up.Laboratory indicators,clinical characteristics and treatment regimens were compared between different subgroups respectively.Multivariate logistic analysis was used to analyze the independent risk factors related to ILD in IIM.The Kaplan-Meier curve was used to evaluate survival of IIM patients in different subgroups and the log-rank test was used to evaluate differences between groups.The risk factors associated with prognosis in IIM patients were carried out by multivariate Cox regression analysis.Recevier operating curve(ROC)was used to determine the best diagnostic threshold of the clinical index and evaluate the diagnostic efficacy.Results:The proportion of men and women was 95 vs 208 of the 303 IIM patients included,DM and PM patients accounted for 224 and 79,respectively among all the patients.The number of patients in ILD group and non-ILD group was 143 / 160(47.2% / 52.8%),respectively,and that in death group and survival group was 75 / 228(24.8% / 75.2%),respectively.The older onset age(comparing to patients under 30 years old,the odds ratio of ILD in patients over 60 years old and patients aged 30 to 60 years old was 5.938 and 7.814,respectively,P=0.003 and P < 0.001),the positivity of anti-Ro52 antibody(OR=2.897,P<0.001)and the positivity of anti-Jo-1 antibody(OR=3.031,P=0.027),the Gottron sign(OR=2.980,P<0.001)and hypoalbuminemia(for every 1g/L increase of serum albumin,OR=0.933,P=0.007)were the independent risk factors for IIM patients with ILD,while the risk of ILD in IIM patients with dysphagia was significantly lower than that in patients without dysphagia(OR=0.310,P=0.001).Survival analysis suggested that the 1-year,5-year and cumulative survival rates of IIM patients in our hospital was 83.2%,74.2% and 69.4%,respectively,while the 1-year,5-year and cumulative survival rates of ILD group and non-ILD group were 76.2%,65.7%,65.7% and 89.4%,81.6%,72.9%,respectively.The Kaplan-Meier curve in subgroup analysis indicated that the cumulative survival rate of DM was significantly lower than that of PM,and the cumulative mortality rate of patients with hypertension,malignant tumor,ILD and pulmonary infection were significantly higher than that of patients without these comorbidities.The cumulative survival rate of patients with heliotrope rash and Gottron sign was significantly lower than that of patients with negative group.In the ILD group,the prognosis of those who received high-dose glucocorticoid therapy were significantly worse than those who did not.Multivariate Cox regression analysis showed that the older onset age(HR=1.034,P=0.001),ILD(HR=1.677,P=0.042),pulmonary infection(HR=2.130,P=0.005),heliotrope rash(HR=2.328,P=0.001),high serum AST(HR=1.001,P=0.013)and hypoalbuminemia(for every 1g/L increase of serum albumin,HR=0.930,P=0.004)were the independent risk factors for the poor prognosis of IIM patients,while anti-Jo-1 antibody(HR=0.220,P=0.039)was the protective factor.The results of ROC curve indicated that the best diagnostic cut-off value of NLR was 6.11 for evaluating the prognosis of IIM(the AUC was 0.642,P<0.001;the sensitivity was 58.1% and the specitifity was 65.0%).Conclusions:1、IIM patients are prone to lung involvement,mainly manifested as interstitial lung disease.The older onset age,the positivity of anti-Ro52 antibody and anti-Jo-1 antibody,the Gottron sign and hypoalbuminemia were the independent risk factors for IIM patients with ILD,while the risk of ILD in IIM patients with dysphagia was significantly lower than that in patients without dysphagia.2、IIM patients had a poor overall prognosis and relatively high mortality,and their survival were affected by many factors.The older onset age,ILD,pulmonary infection,heliotrope rash,elevated serum AST and hypoalbuminemia were the independent risk factors for patients with much unfavorable prognosis,close follow-up should be carried out to formulate a more intensely individualized treatment regimens in clinical practice,while the positivity of anti-Jo-1 antibody was the protective factor for the survival of IIM patients.3、NLR had certain diagnostic value for evaluating the survival and prognosis of IIM patients,and can be used to assist in the clinical evaluation of the prognosis of IIM patients.