A retrospective study for clinical characteristics of 293 patients with dermatomyositis

This retrospective study aimed to investigate differences in clinical characteristics between different antibody phenotypes in patients with dermatomyositis (DM). Two hundred and ninety-three patients with DM were included in this study from September 2018 to September 2023. We collected basic clinical data from the patients, using statistical methods to analyze the clinical characteristics, and used survival analysis and COX regression to assess the prognosis of the patients. In the 293 patients, the antibody distribution was as follows: antibody negative (50, 20.3%), anti-melanoma differentiation-associated gene 5 (MDA5) antibody (104, 42.3%), anti-transcription intermediary factor γ (TIF-γ) antibody (41, 16.7%), anti-complex nucleosome remodeling histone deacetylase (Mi2) antibody (28, 11.4%), anti-nuclear matrix protein 2 (NXP2) antibody (19, 7.7%), anti-small ubiquitin-like modifier activating enzyme (SAE) antibody (4, 1.6%). Interstitial pneumonia (P < .001), lung infection (P < .001), respiratory symptoms (P < .001), arthralgia (P < .001), and fever (P < .001) were more likely to be seen in patients with anti-MDA5 antibody. Malignancy (P < .001) and V-sign (P = .017) were more likely to occur in anti-TIF1-γ antibody positive patients. Anti-NXP2 antibody-positive patients showed more symptoms of muscle involvement, such as myasthenia (P = .002), myalgia (P = .003) and dysphagia (P = .001). In the analysis of prognosis, age at onset (hazard ratio = 1.096, 95% CI: 1.064-1.129, P < .001), fever (hazard ratio = 2.449, 95% CI: 1.183-5.066, P = .016), γ-glutamyl transferase level (hazard ratio = 1.005, 95% CI: 1.002-1.008, P < .001), eosinophil level (hazard ratio = 0.000, 95% CI: 0.000-0.324, P = .024), and complement 3 (C3) level (hazard ratio = 0.115, 95% CI: 0.023-0.575, P = .008) had a statistically significant effect on survival time. The clinical features of DM are associated with myositis-specific antibodies. At the same time, advanced age, fever, elevated γ-glutamyl transferase levels, and reduced C3 and eosinophil levels may be associated with poor prognosis in patients with DM. These data may provide useful information for clinical management of patients with DM.