Clinical significance of radiological patterns of HRCT and their association with macrophage activation in dermatomyositis
Yu Zuo, Lifang Ye, Min Liu, Shanshan Li, Weifang Liu, Fang Chen, Xin Lu, Patrick Gordon, Guochun Wang, Xiaoming Shu
Abstract
OBJECTIVES: To evaluate the distribution of radiological characteristics stratified by different myositis-specific autoantibodies, identify prognostic value of high-resolution CT (HRCT) patterns in DM-associated interstitial lung disease (DM-ILD), and explore the possible mechanism associated with macrophage activation. METHODS: We enrolled 165 patients with PM/DM-ILD. The distribution of HRCT radiological types with different myositis-specific autoantibodies and the relationship between radiological features and ILD course and prognosis were analysed. Additionally, the potential role of macrophage activation in rapidly progressive ILD (RP-ILD) with DM was studied. RESULTS: The organizing pneumonia pattern was dominant in HRCT findings of patients with DM-ILD, especially those with anti-SAE (6/6, 100%) and anti-MDA5 (46/62, 74.2%) antibodies. The ratios of organizing pneumonia and nonspecific interstitial pneumonia patterns were almost equal in patients with aminoacyl tRNA synthetase antibodies, and nonspecific interstitial pneumonia pattern was associated with a mild clinical course. Lower lung zone consolidation in HRCT was related to RP-ILD in both anti-MDA5 and anti-aminoacyl tRNA synthetase antibody-positive groups. Ferritin levels of >1000 ng/ml (odds ratio (OR), 12.3; P=0.009), elevated carcinoembryonic antigen (OR, 5.8; P=0.046) and carbohydrate antigen 19-9 (OR, 7.8; P=0.018) were independent predictors of a lower lung zone consolidation pattern in anti-MDA5 antibody-positive DM. The infiltration of CD163-positive macrophages into alveolar spaces was significantly higher in the DM-RP-ILD group than in the chronic DM-ILD group. CONCLUSION: HRCT patterns are different among variable myositis-specific autoantibodies positive patients with ILD and lower zone consolidation in HRCT correlated with RP-ILD in DM. Activated macrophages may contribute to the pathogenesis of RP-ILD in DM.