Background:The antisynthetase syndrome (SAS) is characterized by the presence of antisynthetase antibodies, anti-JO1, PL7 y PL12 are the most common; and the classic triad of myositis, arthritis, and diffuse interstitial lung disease (ILD)1. Most patients present incomplete forms and the severity of the ILD determines the prognosis of the disease2.Objectives:to analyze epidemiological, clinical and serological characteristics and treatments used in a cohort of patients with SAS.Methods:descriptive study of review of medical records. Data were collected from 15 patients with SAS followed in the Rheumatology and Pneumology consultations of the Virgen Macarena Hospital (Seville) in the last 10 years. The analysis was carried out using the R software.Results:15 patients were included, 8 men and 7 women. The median age was 56 years (33-77). Seven patients (47%) used to smoke. Four patients (27%) met the classical triad. All of them presented ILD and 8 patients (53%) had arthritis and / or myositis. Five (33%) had mechanic’s hands and six of them (40%) presented Raynaud. Seven (47%) suffered from dyspnea before the SAS diagnosis. The median diagnostic delay was 1 month (0-43). Seven (47%) patients had anti-JO1, 1 (7%) anti-PL7, 2 (13%) anti-PL12 and 2 (13%) patients anti-Ro52. Radiological patterns detected by HRCT were: 5 (33%) NINE, 4 (37%) NIU and 6 (40%) others. The initial treatment included mostly (66%) glucocorticoids (GC) and one or more cFAME. In maintenance, mycophenolate was used in 7 patients (47%), cyclosporine 5 (33%), cyclophosphamide in 3 cases (20%), azathioprine in 3 patients (20%) and methotrexate in 3 of them (20%). Four (37%) patients required a combination of DMARDs and 2 cases needed (13%) biological therapy, Rituximab and Tocilizumab. Changes in the mean value of the initial respiratory function tests (FVC1 and DLCO1) and during follow-up (FVC2 and DLCO2) were not relevant (FVC1 81.5% [42-110], FVC2 81% [59-115]; DLCO1 83% [10-112], DLCO2 80.5% [47-108]). Nine patients (60%) remained clinically stable and 3 patients (20%) progressed radiologically. Four patients died from ILD progression.Conclusion:In this study, the incomplete diagnosis of SAS predominated. The most detected antibody was anti-JO1. ILD is present in all cases, with NINE being the most frequent pattern so multidisciplinary management is necessary. Most used treatments were GC and FAMES combined, some cases required biological therapy.References:[1]Irazoque F, et al. Epidemiology, etiology and classification. Reumatol Clin. 2009;5:2-5.[2]Johnson C, et al. Clinical and pathologic differences in interstitial lung disease based on antisynthetase antibody type. Respir Med. 2014; 108(10):1542-8.Disclosure of Interests:None declared