Abstract：Objective: To explore the clinical and imaging features of anti-melanoma differentiationassociated Gene 5 (MDA5) antibody-associated dermatomyositis (DM) combined with interstitial lung disease (ILD) for the benefit of the diagnosis and prognosis of the disease. Methods: We made a retrospective analysis of 81 DM patients with ILD who had been admitted to the Department of Rheumatology and the Department of Aspiration and Critical Care Medicine in the First Affiliated Hospital of Wenzhou Medical University from January 2017 to July 2021. According to test results of anti-MDA5 antibody, the patients were divided into two groups: 26 positive cases (positive group) and 55 negative cases (negative group). General data, imaging features, laboratory examination results and prognosis were analyzed, and the cases of death within half a year were counted. Results: Fever, joint pain, Gottron sign, V sign and skin rash were significantly different between the positive group and the negative group (P<0.05). The single factor analysis of imaging features showed that pleural effusion was more common in the positive group than that in the negative Group, with significant difference(P<0.05). The expression level of carcinoembryonic antigen (CEA), Cytokeratin 19 fragment (Cyfra21-1) and serum ferritin (SF) were higher in the positive group than in the positive group (P<0.05). The results of multivariate analysis showed that there was significant difference in high CEA (≥3.45 μg/L), high Cyfra21-1 (≥11.20 ng/mL) and high SF (≥561.65 μg/L) between the two groups (P<0.05). The area under the ROC curve (AUC) and the sensitivity of the combined detection of CEA and SF in the diagnosis of anti-MDA5 antibody positive DM with ILD were higher than those of the single indicator or combined detection of another two indicators or all three indicators, with the AUC being 0.756 (P<0.001). The sensitivity and specificity of the combined detection of CEA and SF for anti-MDA5 antibody positive DM with ILD were 80.8% and 70.9%, respectively. The death cases of positive group and negative group were 16(61.54%) and 10(18.18%), respectively. The prognosis difference was statistically significant (P<0.05). Conclusion: The clinical and imaging features of patients with anti-MDA5 antibody positive DM combined with ILD were various. The combined detection of CEA and SF is helpful to improve the diagnostic ability of anti-MDA5 antibody positive DM with ILD. The dynamic monitoring of CEA,Cyfra21-1 and SF may be helpful to evaluate the prognosis of anti-MDA5 antibody positive DM combined with ILD.
