ANTISYNTHETASE SYNDROME: NON-ANTISYNTHETASE ANTIBODIES, CLINICAL MANIFESTATIONS AND OVERLAPS

Background: The antisynthetase syndromes (ASSD) are characterized by the presence of anti-aminoacyl transfer RNA synthetase (ARS) autoantibodies and clinical features including myositis, arthritis, interstitial lung disease (ILD), Raynaud’s phenomenon (RP), mechanic hands (MH), and fever. Two aSSD diagnosis criteria have been developed; those proposed by Connors, and the stricter criteria proposed by Solomon (1, 2). Additionally, other symptoms of connective tissue diseases (CTD) can be present. Objectives: To describe a series of patients with positive aRS and analyze: 1) the associated non-ARS antibodies, 2) the clinical manifestations that are not included in the different aSSD diagnosis criteria; and 3) the initial diagnosis attributed by the Rheumatologist in the clinical records. Methods: We performed an observational retrospective study in two hospitals. All patients with clinical suspicion of aSSD or myopathy and positive aRS in the myositis immunoblot (Euroimmun assay) were included. Results: We analyzed 37 patients; 70.3% woman, with a mean age at the moment of the first symptom of 50.5 (SD±14.0) years, and 51.4 (SD±14.0) years at the moment of the aRS detection. The frequency of aRS was: anti-Jo1 (n=17), anti-PL12 (n=8), anti-PL7 (n=4), anti-EJ (n=4), and anti-OJ (n=4). The rate of the aSSD clinical manifestations was: arthritis (56.7%), ILD (54.1%), muscle weakness (48.6%), RP (37.8%), MH (29.7%) and fever (21.6%). Thirty-four patients (91.9%) met Connors’ criteria and 17 of them (45.9%) also met Solomon’s criteria. Non-antisynthetase characteristics: - associated non-ARS antibodies: anti-Ro52 (n=17, 46%); anti-PM/Scl75 (n=6, 16.2%); anti-PM/Scl100 (n=5, 13.5%); anticentromere (n=3, 8.1%); rheumatoid factor (n=2, 5.4%); anti-CCP (n=2, 5.4%); and anti-DNAds (n=2, 5.4%). Other antibodies detected only once: anti-SRP, lupic-anticoagulant, anti-Ku, anti-Mi2, anticardiolipin, Nor90, Th/To. - Most frequent clinical manifestations not included in the aSSD diagnosis criteria: dysphagia (n=10, 27%); dermatomyositis rash (n=9, 24.3%); and SICCA sympthoms (n=7, 18.9%). - First diagnosis attributed by the clinicians in the medical records: aSSD (n=19, 51.35%), dermatomyositis/polymyositis (DM/PM) (n= 3), overlap syndrome (n= 3), systemic lupus erythemoatous (SLE) (n= 3), primary Sjögren’s syndrome (SS) (n=2); rheumatoid arthritis (RA) (n=2); undiferenciated-CTD (UCTD) (n=2); and Systemic Sclerosis (SSc) (n=1; 2.7%). Overlaps included 2 DM/PM-SSc and 1 DM/PM-SS, and both UCTD was described with SSc pattern. Thus, of the 18 cases not diagnosed as aSSD, 6 (33.3%) presented DM/PM diagnosis pattern and 6 (33.3%) SSc pattern. - additionally, when we applied the aSSD diagnosis criteria, 7 of the 18 cases (38.8%) not diagnosed as aSSD by the Rheumatologist fulfilled Solomon’s criteria. Conclusion: In our series, the most frequent non-ASSD profiles associated to aRS positivity was DM/PM, SSc and Sjögren’s syndrome. This, considering the most frequently associated non-ARS, the most frequent non-ASSD clinical manifestations and that the most frequent non-ASSD diagnosis diagnoses or profiles described by the Rheumatologist. Our results suggest that aRS can be present in patients with other CTD without presenting aSSD, and additionally that aSSD can be present in overlaps with other CTD. REFERENCES: [1] Solomon J, et al. Jornal brasileiro de pneumologia. 2011;37(1):100-9. [2] Connors GR, et al. Chest. 2010;138(6):1464-74. Disclosure of interests: Martín Greco: None declared, María Jesús García de Yébenes: None declared, inmaculada alarcón: None declared, anahy Brandy-Garcia: None declared, Iñigo Rua-Figueroa: None declared, Estíbaliz Loza Grant/research support from: Roche, MSD, Pfizer, abbvie, BMS, UCB, actelion, Celgene, Grunenthal and Sanofi, Teresa Oton: None declared, R. López-Sánchez: None declared, Laur Cáceres Martín: None declared, Loreto Carmona Grant/research support from: abbvie, actelion, astellas, BMS, Eisay, Gebro Pharma, Grünenthal, Leo Pharma, Lilly, MSD, Novartis, Pfizer, Roche, Sanofi-Aventis and UCB Pharma, Paid instructor for: Novartis DOI: 10.1136/annrheumdis-2019-eular.7149Citation: Ann Rheum Dis, volume 78, supplement 2, year 2019, page A1789Session: Scleroderma, myositis and related syndromes (Scientific Abstracts)