抗ARS抗体阳性和抗MDA5抗体阳性皮肌炎/多发性肌炎相关间质性肺疾病的定量CT特征比较

Objective This study aimed to investigate the difference of quantitative CT features of the lung in patients with anti-aminoacyl tRNA synthetase (ARS) antibody-positive and anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis/polymyositis-associated interstitial lung disease (DM/PM-ILD). Methods A cross-sectional study was conducted on 167 patients with DM/PM-ILD diagnosed in the First Affiliated Hospital of Xi 'an Jiaotong University from November 2012 to November 2022. The patients included 57 males and 110 females aged 19-78 (53.1±11.6) years and were divided into two groups according to the type of antibodies. The anti-ARS group included 123 anti-ARS antibody-positive patients, and the anti-MDA5 group included 44 anti-MDA5 antibody-positive patients. All patients underwent chest CT, and the CT images were imported into the "digital lung" analysis platform for processing. The quantitative CT parameters of the whole lung and each lobe were compared between the two groups. Observational index: (1) The baseline data of two groups were compared. (2) The parameters compared were lung volume, mean lung density, pulmonary vascular volume (IPVV), and percentage of lung volume with CT value less than -950 Hu in the whole lung and each lobe volume (LAA%_-950). Results (1) Age and body mass index had no statistically significant differences between the two groups (all P values > 0.05). Duration was statistically significantly differences in gender distribution and the course of disease between the two groups (χ²=19.71, Z=-3.17, all P values < 0.05). (2) In the anti-ARS group, the lung volumes of the whole lung, left lung, right lung, right middle lobe, lower lobe, and left lower lobe were lower than those in the anti-MDA5 group. The mean lung density of the right lung, right middle lobe, lower lobe, and left lower lobe were higher than those in the anti-MDA5 group. The IPVV of the whole lung, left lung, right lung, right middle lobe, lower lobe, and left lower lobe were lower than those in the anti-ARS group. The LAA%_-950 in the middle and lower lobes of the right lung and the upper and lower lobes of the left lung in the anti-ARS group were lower than those in the anti-MDA5 group, and the differences were statistically significant (all P values < 0.05). Conclusion Quantitative CT can objectively and accurately evaluate differences in lung imaging features in patients with DM/PM-ILD positive for anti-ARS antibody and anti-MDA5 antibody. This work provides theoretical basis for clinicians to evaluate the condition of patients with DM/PM-ILD and design personalized diagnosis and treatment.