Phenotypic Profiles Among 72 Caucasian and Afro-Caribbean Patients with Antisynthetase Syndrome Involving Anti-PL7 or Anti-PL12 Autoantibodies

Abstract

Objectives: Antisynthetase syndrome (ASyS) is a rare autoimmune disease. We aimed to determine clinical, biological, radiological, and evolutive profiles of ASyS patients with anti-PL7 or anti-PL12 autoantibodies.

Methods: We performed a retrospective study that included adults with overt positivity for anti-PL7/anti-PL12 autoantibodies and at least one Connors' criterion.

Results: Among 72 patients, 69% were women, 29 had anti-PL7 and 43 anti-PL12 autoantibodies, median age was 60.3 years, and median follow-up period was 52.2 months. At diagnosis, 76% of patients had interstitial lung disease, 61% had arthritis, 39% myositis, 25% Raynaud's phenomenon, 18% mechanic's hands, and 17% had fever. The most frequent pattern on initial chest computed tomography was non-specific interstitial pneumonia and 67% had fibrosis at last follow-up. During follow-up, 12 patients had pericardial effusion (18%), 19 had pulmonary hypertension (29%), 9 (12.5%) had neoplasms, and 14 (19%) died. Sixty-seven patients (93%) received at least one steroid or immunosuppressive drug. Patients with anti-PL12 autoantibodies were younger (p=0.01) and more frequently exhibited anti-SSA autoantibodies (p=0.01); patients with anti-PL7 autoantibodies had more severe weakness and higher maximum creatine kinase levels (p=0.03 and 0.04, respectively). Initial severe dyspnoea was more common in patients from the West Indies (p=0.009), with lower predicted values of forced vital capacity, forced expiratory volume in 1s, and total lung capacity (p=0.01, p=0.02, p=0.01, respectively) contributing to a more severe 'respiratory' initial presentation.

Conclusions: The high mortality and significant numbers of cardiovascular events, neoplasms and lung fibrosis in anti-PL7/12 patients justify close monitoring and question addition of antifibrotic drugs.

Keywords: Anti-PL12; Anti-PL7 autoantibody; Antisynthetase syndrome; Idiopathic inflammatory myopathy; tRNA synthetase autoantibody.