Clinical-imaging characteristics and management of anti-JO-1 and non-JO-1 anti-synthetase syndrome-associated interstitial lung disease

Objectives Given a substantial proportion of patients with ASS-ILD (anti-synthetase syndrome-associated interstitial lung disease) develop progressive pulmonary fibrosis (PPF), we aimed to investigate the clinical-radiographic characteristics and treatment in patients with or without anti-Jo-1 antibody. Methods Patients diagnosed with ASS-ILD from two centers were retrospectively reviewed and stratified into subgroups according to the anti-synthetase antibody. Demographic, clinical features, radiographic patterns, pulmonary function tests, management, and mortality were compared. Results In total, 377 patients were recruited, comprising 169 (44.8%) with anti-Jo-1 and 208 (55.2%) without, including 89 (23.6%) with anti-EJ, 72 (19.1%) with anti-PL-7, 39 (10.3%) with anti-PL-12 and 8 (2.1%) with anti-OJ. Patients with non-Jo-1 had significantly longer diagnostic durations (p= 0.037), hyperglobulinemia (p< 0.05), and more frequently combined with secondary Sjögren’s syndrome (p= 0.003) compared with those with anti-Jo-1. Regarding the radiographic patterns, patients with Anti-Jo-1 antibody frequently showed an organizing pneumonia pattern (15.6%) in chest high-resolution computed tomography (HRCT), while non-Jo-1 exhibited the fibrotic radiographic patterns, including usual interstitial pneumonia (UIP) (43.3%) and nonspecific interstitial pneumonia (NSIP) (52.2%). Moreover, patients with anti-Jo-1 had received an increased corticosteroids dose. Despite these, antifibrotic treatments and mortality were comparable between patients with anti-Jo-1 and non-anti-Jo-1. Conclusion Patients with ASS-ILD had distinctive clinical-imaging characteristics among the different antibodies, and non-anti-Jo-1 patients were susceptible to presenting a fibrotic phenotype. Further long-term study is needed to investigate the disease behaviour to guide optimal treatment strategy.