Differences in clinical features of interstitial lung disease between polymyositis and dermatomyositis / 中华风湿病学杂志

ABSTRACT

Objective To assess if there are differences in clinical features and prognosis of intersti-tial lung disease(ILD) between polymyositis(PM) and dermatomyositis(DM). Methods Medical records of 114 patients with PM/DM(31 PM-ILD, 83 DM-ILD) were reviewed retrospectively to analyze the demograph-ics , clinical manifestations, laboratory findings, high-resolution computed tomography (HRCT), pulmonary function tests (PFTs), blood gas analysis, treatments and prognosis. The differences of measured data were detected by descriptive statisitical analysis, and rates were detected by four-fold table Chi-Square test and Fisher′s exact test. Results The incidence of PM/DM-ILD was 35.8%(114/318) in this study, and DM was more prone to have ILD (χ2=5.019, P=0.025). There were significant difference in sex ratio between PM-ILD and DM-ILD(χ2=4.929, P=0.026). Arthralgia/arthritis was more common in DM-ILD than PM-ILD(χ2=7.756, P=0.005). In PM-ILD, ILD was often present before the diagnosis of PM (χ2=15.555, P sion (χ2=6.322, P=0.012) were more frequently observed in PM-ILD, while patchy shadows were more frequent in DM-ILD (χ2=5.105, P=0.024). There was no difference in PFTs and blood gas analysis between the two groups. With the similar therapeutic regimen, the prognosis of DM-ILD was significantly worse than in PM-ILD (χ2=7.595, P =0.006). Conclusion There are significant differences in sex ratio, clinical manifestations, HRCT imaging findings, and prognosis between PM-ILD and DM-ILD. We propose that the difference in the immunopathological processes of PM and DM leads to different clinical features of ILD between PM and DM.