AB0590 CLINICAL AND DEMOGRAPHIC CHARACTERISTICS OF PATIENTS WITH ANTISYNTHETASE AUTOANTIBODIES: DATA FROM A PORTUGUESE TERTIARY OUTPATIENT CLINIC
Authors: P. Martins, E. Dourado, A. T. Melo, N. Khmelinskii, I. Cordeiro, R. Campanilho-Marques
Journal: Annals of the Rheumatic Diseases (2020)

Background: Antisynthetase syndrome (AS) may have different clinical phenotypes and outcomes associated with different anti-aminoacyl RNA-synthetase (anti-ARS). Patients may also present with incomplete/early phenotypes that do not fulfil the classification criteria. Objectives: To evaluate the clinical and demographic characteristics of patients positive for anti-ARS in our Myositis clinic. Methods: Observational study using data from the Portuguese Rheumatic Diseases Register (Reuma.pt/Myositis protocol). Data extracted included demographic variables, clinical features and immunological expression of the disease. Results: 17 patients were identified. All met the criteria for AS according to Connors criteria, while 3 did not met according to the Solomon criteria. Mean age at diagnosis was 60.1 years (26 - 80) and 76.5% were female. Mean follow-up time was 2.8 (0.5-9) years. Only 3 patients had history of smoking in the past. The autoantibodies expressed were anti-Jo1 (n=12), anti-PL12 (n=2), anti-OJ (n=2) and anti-PL7 (n=1). 4 patients positive for anti-Jo-1 also expressed anti-Ro52. The clinical information and treatment are described in table 1. One patient presented as a paraneoplastic syndrome associated with anti-Jo-1. Table 1. Demographic and clinic characteristics of our cohort. AZA – azathioprine; CYC – Cyclophosphamide; DM – dermatomyositis; GS – Gottron’s sign; ILD – Interstitial lung disease; PM – Polymyositis; NSIP - Nonspecific interstitial pneumonia; MH – mechanic hands; MMF - Mycophenolate mofetil; MTX – Methotrexate; PDN – prednisolone; RP – Raynaud phenomenon; RTX – Rituximab; UIP - Usual interstitial pneumonia; Y – yes; N – no. Connors criteria – anti-ARS plus one or more of RP, MH, arthritis, ILD, fever. Solomon criteria – anti-ARS plus 2 major criteria or 1 major and 2 minor criteria. *induction therapy. Case Serology Major criteria (ILD [NSIP/UIP/non-specific] or PM/DM ) Minor criteria (Arthritis, MH, RP ) Other manifestations Connors (2010)/ Solomon (2011) criteria PDN DMARDcs (MTX/MMF/AZA ) CYC/RTX 1 Jo1 PM MH, arthritis GS Y/Y Y MMF - 2 Jo1 NSIP RP, MH Asthenia Y/Y Y AZA - 3 Jo1 NSIP MH, arthritis Calcinosis, asthenia Y/Y Y AZA - 4 Jo1 NSIP; DM - GS Y/Y Y - - 5 Jo1/Ro52 PM MH, arthritis GS, asthenia Y/Y Y MTX - 6 Jo1 UIP RP, arthritis Asthenia Y/Y Y - RTX 7 Jo1/Ro52 NSIP; PM arthritis - Y/Y Y MMF CYC* 8 Jo1 NSIP; PM - - Y/Y Y MMF - 9 Jo1/Ro52 NSIP; PM - - Y/Y Y AZA - 10 PL7 - RP, arthritis, MH Dysphagia Y/N Y - - 11 Jo1 - RP Asthenia Y/N - - - 12 Jo1/Ro52 PM MH, arthritis GS, asthenia Y/Y Y MMF - 13 PL12 PM RP, arthritis GS, asthenia Y/Y Y MMF - 14 Jo1 UIP RP, arthritis Weight loss, asthenia Y/Y Y - RTX 15 OJ Non-specific pattern - - Y/N Y MMF - 16 OJ NSIP - - Y/Y Y - - 17 PL12 PM RP, MH - Y/Y - - - Conclusion: The most frequent autoantibody was anti-Jo-1, which is consistent with the literature. Interestingly, patients with anti-PL, usually described as having severe lung disease, in our series do not have it. Additionally, we found a trend for a younger age at diagnosis in Jo1 positive patients and remarkably more than half of these patients have been diagnosed with ILD, being the NSIP pattern the most frequently reported. Disclosure of Interests: None declared