Clinical characteristics and prognostic analysis of idiopathic inflammatory myopathy with positive anti‐aminoacyl‐tRNA synthetase antibodies: A single center experience

OBJECTIVES: To identify the differences of clinical characteristics, laboratory findings, and the long‐term outcomes in patients with anti‐synthetase syndrome (ASS) of different anti‐aminoacyl‐transfer RNA synthetase antibodies. METHODS: We retrospectively enrolled 119 patients with ASS, and the clinical characteristics and laboratory findings were collected. Additionally, multivariate COX regression analysis was performed to estimate the risk factors of prognosis in patients with ASS. RESULTS: The frequency of interstitial lung disease (ILD) reached 93.3% in our cohort, of 28 (23.5%) was classified as rapidly progressive (RP)‐ILD. The highest incidence of RP‐ILD was 36.4% in the PL12 group of ASS patients. The ILD group was characterized by an older age, a lower prevalence of V sign, and a higher prevalence of pulmonary symptoms when contrasted with the non‐ILD group. There were statistical differences of clinical significance in arthritis, myositis, mechanic's hands, triad, shawl sign, V sign, and Raynaud's phenomenon among the four subgroups (all p < .05). Additionally, the prevalence rates of arthritis, myositis, mechanic's hands, triad, and V sign in the anti‐Jo1 antibody‐positive group were significantly higher than anti‐Jo1 antibody‐negative patients with ASS (all p < .05). Multivariate Cox regression analysis showed mechanic's hands (odds ratio [OR] = 6.47, p < .001), anti‐nuclear antibodies (ANA) (OR = 2.13, p = .026), ILD (OR = 10.50, p < .001), and V sign (OR = 0.30, p = .007) were independent factors affecting the prognosis of patients with ASS. The incidences of RP‐ILD, arthritis, myositis, triad, mechanic's hands, and shawl sign were more frequent in the anti‐Ro52 antibody‐positive group than the anti‐Ro52 antibody‐negative patients with ASS (all p < .05). CONCLUSIONS: Patients with ASS accompanied with ILD are highly prevalent. Mechanic's hands, ANA, and ILD may be a potential biomarker for predicting a poor prognosis in patients with ASS. Additionally, the detection of the anti‐Ro52 antibody provides valuable insights for managing and predicting disease progression and long‐term outcomes.