Clinical characteristics of 11 cases of anti-melanoma differentiation associated gene 5 autoantibody-positive juvenile dermatomyositis / 中华实用儿科临床杂志

ABSTRACT

Objective:To clarity the clinical features of juvenile dermatomyositis (JDM) with positive anti-melanoma differentiation associated gene 5 (MDA5) antibody.Methods:Retrospective study.Clinical data of 11 anti-MDA5 autoantibody-positive JDM patients in the Department of Rheumatology and Immunology, Children′s Hospital Affiliated to Capital Institute of Pediatrics from January 2016 to January 2019 were retrospectively recruited for analyzing their clinical characteristics, pulmonary imaging and pulmonary function, thus summarizing treatment experiences.Results:A total of 11 children with anti-MDA5 autoantibody-positive JDM were recruited, involving 2 males and 9 females, with the average onset age of 1-13 (5.8±4.2) years.Clinical manifestations included rash in 11 cases (100.0%), arthritis in 5 cases (45.5%), and myasthenia in 4 cases (36.4%). Muscle enzyme elevated in 10 cases (90.9%) and serum ferritin (SF) elevated in 9 patients (81.8%). Ten cases (90.9%) showed interstitial lung disease (ILD), manifesting as ground glass opacity at subpleural area on CT scans, restrictive ventilation and decreased diffusion function on lung function test, while respiratory symptoms were absent.All patients were treated with glucocorticoid combined with immunosuppressor.Case 2 developed into rapid progressive pulmonary interstitial disease (RPILD), and died of respiratory failure 2 months later.The remaining was followed up for 1-2 years, and the ILD was relieved.Conclusions:All recruited children with anti-MDA5 autoantibody-positive JDM presented typical rash, and mild muscle weakness with a greater tendency to arthritis.Chinese pediatric patients are prone to complicate with ILD with no respiratory symptoms, but ground glass opacity at subpleural area on CT, and restrictive ventilation and decreased diffusion function on lung function test can be detected.Elevated SF is associated with the development of ILD.Glucocorticoid combined with immunosuppressive therapy is effective to JDM with ILD, but ineffective for RPILD.The mortality of anti-MDA5 autoantibody-positive JDM is high without an effective treatment.