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

OBJECTIVES: Given that a substantial proportion of patients with anti-synthetase syndrome-associated interstitial lung disease (ASS-ILD) develop progressive pulmonary fibrosis (PPF), we aimed to investigate the clinical-radiographic characteristics and treatments in patients with or without anti-Jo-1 antibodies. METHODS: Patients diagnosed with ASS-ILD from two centres were retrospectively reviewed and stratified into subgroups according to the anti-synthetase antibody. Demographic, clinical features, radiographic patterns, pulmonary function tests results, management, and mortality were compared between the various antibody subgroups. 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 periods (P = 0.037), had more hyperglobulinemia (P < 0.05), and their ASS-ILD was more frequently combined with secondary SS (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 CT (HRCT), while non-Jo-1 exhibited the fibrotic radiographic patterns, including usual interstitial pneumonia (UIP) (43.3%) and non-specific interstitial pneumonia (NSIP) (52.2%). Moreover, patients with anti-Jo-1 had received an increased CS dose. Despite these differences, 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 associated with 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 provide guidance for an optimal treatment strategy.