The Clinical Features And Prognostic Analysis Of Patients With Anti-MDA5 Antibody Positive Dermatomyositis Complicated With Interstitial Lung Disease

Objective This article aims to study the clinical characteristics,disease outcome and prognosis of patients with anti-melanoma differentiation-related gene 5(MDA5)antibody positive in dermatomyositis(DM)secondary pulmonary interstitial disease(ILD),so as to provide clinical evidence for further understanding Anti-MDA5 antibody related ILD.Methods Collect DM-ILD patients who were hospitalized or outpatients in the First Affiliated Hospital of Guangxi Medical University and were sent to a third-party medical laboratory to check the myositis antibody profile from August 1,2016 to February 1,2021.The clinical symptoms,signs,laboratory indicators,HRCT performance,treatment plan,survival time and other datas of the anti-MDA5 antibody positive group and the anti-MDA5 antibody negative group of the patients were analyzed.The independent sample t test was used to compare and analyze the clinical characteristics of the death group and the survival group in the follow-up patients;The Kaplan-Meier was used to compare the survival rate between the two groups,and the Cox regression analysis method was used to evaluate the prognostic risk factors.Results : 1.A total of 45 DM-ILD patients were collected in this study.There were 22 patients with positive anti-MDA5 antibodies,including 6 males and 16 females;the median duration of the disease was 2.34 months,and the average age of onset was 46.77±11.90 years.There were 23 patients with negative anti-MDA5 antibodies,including 4 males and 19 females;the median duration of the disease was 4 months,and the average age of onset was48.26±11.48 years.There were 18 Han patients in the anti-MDA5 antibody positive group,which was more than 12 Han patients in the negative group(P=0.023).2.The common clinical manifestations of DM-ILD patients are myalgia/muscle weakness(84.4%),joint pain(66.7%),Gottron sign(51.1%),shortness of breath after activity(51.1%),cough/sputum expectoration(51.1%)etc.Compared with anti-MDA5 antibody-negative ILD patients,anti-MDA5antibody-positive patients have periorbital purplish red edema [11/22 cases(50%)vs 5/23 cases(21.7%)],Gottron sign [16/ 22 cases(72.7%)vs 7/23 cases(30.4%)],skin ulceration [10/22 cases(45.5%)vs 1/23 cases(4.3%)],joint pain[20/22 cases(90.9%))vs 10/23 cases(43.5%)] had a higher positive rate(all P<0.05).3.Compared with the anti-MDA5 antibody negative group,the WBC,HGB,PLT,CK,LD,UA of the positive group decreased,and the ALP,GGT,Scr,ESR increased(all P<0.05);and the tumor markers CEA,CA199 increased(P<0.01);and the positive rate of ANA medium and high titer(≥1:320)is low(P=0.021).There were significantly more RP-ILD patients with positive anti-MDA5 antibodies than the negative group [7/22 cases(31.8%)vs 1/23 cases(4.3%),P=0.043].Comparing the HRCT scores of the patients,we found that the GGO score of the positive group was higher than that of the negative group(4.59±1.82 vs 3.17±1.85,P=0.013).There were 20 patients with perfect pulmonary function test,10 in the positive group and 10 in the negative group.The average level of DLco of all patients was lower than the normal value.The FEV1,FVC,and VC of the positive group were higher than those of the negative group(P<0.01).4.Among the 22 subgroups of anti-MDA5 antibody-positive patients,they were divided into 7 cases in the RP-ILD group and 15 cases in the non-RP-ILD group.Patients in the RP-ILD group had lower UA,but GGO score,type I respiratory failure,and the use of globulin and mortality were higher(all P<0.05).5.In the end,36 patients had follow-up outcomes,with an average follow-up of 17(7.25,30.25)months,of which 9 died and 27 survived.The anti-MDA5 antibody positive group had a higher mortality rate than the negative group [8/19 cases(42.1%)vs 1/17 cases(5.9%),P=0.02],and the higher the anti-MDA5 antibody titer,the higher the mortality rate high.Compared with the DM-ILD survival group,the death group had higher ESR and anti-MDA5 antibody positive rates,lower WBC,and more patients with type I respiratory failure and RP-ILD(all P<0.05).The median survival time of patients in the death group was much lower than that in the survival group(1.33 months vs 22 months,P<0.01).6.The anti-MDA5 antibody positive group had a survival rate of 78.9%,63.2%,and 63.2% in the first,third,and sixth months.The negative group had a survival rate of 100%,94.1%,94.1% in the first,third,and sixth months.94.1%。The comparison between the two groups was statistically different(P=0.01).7.In the Cox regression analysis,through the single factor analysis method,we found that anti-MDA5 antibody positive,RP-ILD,type I respiratory failure are the influencing factors of the poor prognosis of DM-ILD patients,and elevated WBC is the protective factor.Through multivariate analysis,we found that RP-ILD is an independent risk factor for death in patients with DM-ILD.Conclusions:1.Anti-MDA5 antibody-positive DM-ILD patients are more common in Han nationality,prone to typical dermatomyositis rash,high disease activity,low ANA titer,more common ground glass shadows in the lungs,easy to progress to RP-ILD,and death The rate increases.2.Anti-MDA5 antibody positive combined with RP-ILD patients,their uric acid decreased,GGO scores increased,which were prone to type I respiratory failure,and the mortality rate of these patients increased.3.Anti-MDA5 antibody positive,RP-ILD,type I respiratory failure are the influencing factors of poor prognosis in patients with DM-ILD,and elevated WBC is a protective factor,and RP-ILD is an independent risk factor for death in DM-ILD patients.