Characterization Of Clinical Features Of Dermatomyositis Patients With Different Initial Manifestations

ObjectiveOur study aimed to characterize the clinical features and laboratory results from dermatomyositis(DM)patients with different initial symptoms,and we expected that the results of these analyses will improve our understanding of DM,reduce delayed or misdiagnosis,propose customized treatment,and improve the prognosis of the patients.MethodsA retrospective analysis was performed on 136 DM patients hospitalized in the First Affiliated Hospital of Zhengzhou University between January 1 of 2019 to January 1 of 2021.According to different first symptoms,patients were divided into rash vs non-rash group,muscle weakness vs non-muscle weakness group,arthritis vs non-arthritis group,respiratory symptoms vs non-respiratory group.Patients with interstitial lung disease(ILD)were divided into ILD respiratory symptoms group and ILD non-respiratory symptoms group.General clinical characteristics and laboratory data were recorded and analyzed from patients with different initial manifestations.SPSS 25.0 and GraphPad Prim 9.0 statistical software were used for analysis,and Kaplan-Meier survival curve was plotted to compare the survival rate of the two groups in ILD patients.P<0.05 was considered statistically significant.Results1.Among the 136 patients with DM in this study,the male to female ratio was 1:2.7.The patients were aged from 19 to 72 years old,and average age of onset was 49.68±11.79 years.Rash(n=55,40.4%)was the most common initial symptoms of DM,followed by respiratory symptoms(n=30,22.1%),arthritis(n=27,19.9%),muscle weakness(n=13,9.6%)and other symptoms(n=11,8.1%).Other initial manifestations included fever(n=7),diarrhea(n=3),oral ulcer(n=1).2.Patients in rash group had a lower incidence of ILD,respiratory symptoms and arthritic symptoms,with statistically significant(P=0.004,P=0.000,P=0.003).High-density lipoprotein and DLCO%were higher in rash group patients(P=0.012,P=0.011).Muscle weakness group had a higher gastrointestinal incidence,total cholesterol,triglyceride,FEV1/FVC and MMEF%(P=0.033,P=0.034,P=0.038,P=0.001,P=0.026).The digestive tract symptom involvement rate,creatine kinase and lactate dehydrogenase were lower in arthritis group(P=0.035,P=0.005,P=0.026).The incidence of ILD was higher in respiratory symptom group,and the levels of MMEF%,FVC%and DLCO%were lower in respiratory symptom group(P=0.000,P=0.001,P=0.000,P=0.000).In all ILD patients,compared with the ILD non-respiratory symptom group;ILD respiratory symptom group had a lower joint involvement rate,and lower levels of MMEF%,FVC%and DLCO%(P=0.026,P=0.006,P=0.001,P=0.001).However,there was no significant difference in survival rate between the two groups in DM-ILD patients(χ2=0.648,P=0.421).3.In terms of myositis specific antibodies,the positive rate of anti-TIF1γantibody was higher in rash group(P=0.000).Arthritis group patients and respiratory group patients had a lower positive rate of anti-TIF1γ antibody(P=0.029,P=0.018).Arthritis group had a higher positive rate of anti-MDA5 antibody(P=0.014,P=0.029).ConclusionThere are differences in clinical characteristics,myositis antibodies and laboratory indicators among patients with different first symptoms.In DM-ILD,patients with respiratory symptoms as the first manifestation often present more severe restrictive ventilatory dysfunction and pulmonary diffuse dysfunction.