Abstract: Objective To analyze retrospectively clinical manifestations and prognostic factors of interstitial lung disease (ILD) in patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis(DM). Methods The patients with DM-ILD admitted to Kailuan General Hospital between January 2017 and April 2018 were selected as subjects including 9 patients with anti-MDA5 antibody positive (4 survivors，5 deaths) and 9 patients with anti-synthase (ARS)-antibody positive. The clinical manifestations were compared between the two groups. Cox regression analysis adjusted for age and sex was used to determine prognostic factors for anti-MDA5 antibody-related ILD. Results Compared with ARS-ILD patients, krebs von den lungen 6 (KL-6), alanine aminotransferase (ALT), glutamyltransferase (GGT) and ferritin levels were significantly higher in MDA5-ILD patients (P＜0.05). There were no significant differences in age, sex, incidence of CADM, creatine kinase (CK), KL-6, lactate dehydrogenase (LDH), aspartate aminotransferase (AST),ALT, GGT, C-reactive protein (CRP) and ferritin levels between 4 survivors and 5 dead patients (all P＞0.05). After adjusting confounding factors, the level of ferritin was not associated with the prognosis of anti-MDA5 antibody positive patients. Conclusion Anti-MDA5 antibody is an important index for early diagnosis of DM complicated with acute /subacute interstitial pneumonia (A / SIP). It has not yet been demonstrated that the level of ferritin is associated with the severity of disease and prognosis of anti-MDA5 antibody-related ILD.

Key words: dermatomyositis, interstitial lung disease, melanoma differentiation related gene 5, ferritin, macrophage activationactivation