Objective: To analyze the clinical features and outcomes of the patients with anti-glycyl tRNA synthetase (anti-EJ) syndrome in a large Chinese cohort.
Methods: The medical records, imaging, and serologic data of patients with anti-EJ antibodies from the China-Japan Friendship Hospital database were retrospectively investigated. Anti-EJ antibodies were identified using immunoblot assay. Long-term follow-up was conducted.
Results: Anti-EJ antibodies were present in 46 (19.7%) of the 234 patients with antisynthetase syndrome (ASS), preceded by anti-Jo-1 and anti-PL-7 antibodies. The mean age of disease onset was 51.2 ± 15.9 years, and 69.6% of these patients were female. The most prevalent clinical feature was interstitial lung disease (ILD) (96.7%), which was also the most common initial manifestation, followed by fever (60.9%), mechanic's hands (56.5%), muscle involvement (50%), and Raynaud phenomenon (8.7%). Ten (21.7%) patients developed rapidly progressive ILD (RP-ILD). Organizing pneumonia (OP) on high-resolution computed tomography (HRCT) scans (OR = 37.5, p = 0.006) and a higher C-reactive protein-to-albumin ratio (CAR) (OR = 28.3, p = 0.01) were independent risk factors for RP-ILD. Muscular pathological features were heterogeneous. Concomitant infection was noted in 63.0% of the patients during the disease course. Hypoalbuminemia (OR = 0.759, p = 0.002) was an independent risk factor for concomitant infection. Patients responded well to glucocorticoid therapy. The 5- and 10-year survival rates of the patients with anti-EJ were 97.8% and 88%, respectively.
Conclusion: Anti-EJ syndrome was found to be a relatively common ASS subtype, with a favorable outcome. A notable proportion of the patients experienced RP-ILD, which was prone to OP on HRCT and a higher CAR, and needed aggressive management. Key Points • ILD was the most common initial manifestation of anti-glycyl tRNA synthetase syndrome. • RP-ILD was notable in anti-EJ positive patients. • Anti-EJ positive patients possessed a favorable long-term prognosis, but easily relapsed.
Keywords: Anti-EJ antibodies; Interstitial lung disease; Prognosis.