SESSION TITLE: Pulmonary Manifestations of Systemic Disease Posters SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, October 28, 2015 at 01:30 PM - 02:30 PM PURPOSE: The purpose of this study is to evaluate the effects of Rituximab and Mycophenolate (MMF) in the treatment of Anti-synthetase Syndrome (ASS) by comparing subjective and objective measures of pulmonary function and extrapulmonary manifestations, before and six months after treatment. METHODS: Retrospective review of five patients diagnosed with ASS and treated for greater than six months. RESULTS: Five patients were diagnosed with ASS with associated ILD. Two patients were positive for Jo-1, one for PL-7, one for PL-12 and one for MI-2 antibodies. The radiologic patterns were Non-specific Interstitial Pneumonitis (NSIP) in three cases, and Organizing Pneumonia (OP) and no classifiable radiologic pattern in one each. The patients positive for PL-7 and PL-12 antibodies presenting with isolated pulmonary involvement, while Myositis, Raynaud's phenomenon, arthritis and Mechanic hands were present in all the other three cases. Rituximab was given in one of the Jo-1 and in the MI-2 positive patients, who presented with myositis and arthritis and in the PL-12 case due to severe ILD. MMF was offered as an additional therapy in all these cases and as only treatment in the other two. In a 6 months period, four patients experienced improved dyspnea, decreasing one NYHA class, increase in Forced Vital Capacity (FVC) and DLCO, by average of 290ml and 1.84ml/min/mmHg, respectively, and in 2 patients oxygen requirement were weaned by 8LPM each. The three patients with extrapulmonary manifestations demonstrated good control of those and in all of the patients was possible to reduce the steroid dose. CONCLUSIONS: Use of MMF and/or Rituximab in our patients with AS Syndrome yielded improvement in subjective and objective measures of pulmonary function and extrapulmonary manifestations. CLINICAL IMPLICATIONS: ASS is a newly recognized clinical entity, with ILD being a key feature, which contributes to the morbidity and mortality of the disease. Treatment is not clearly established. We hypothesize than in presence of significant extrapulmonary manifestations, advanced, or refractory cases, Rituximab should be considered first line of therapy, supported by different trials demonstrating its good effect over both lung and other manifestations, mainly myositis. However, the high risk for relapse suggests maintenance therapy is indicated, MMF represents a good option, based on recent studies in Connective Tissue Disease (CTD)-associated ILD. Our study adds to the limited data available regarding treatment of ASS. DISCLOSURE: The following authors have nothing to disclose: Andres Borja Alvarez, Sarah Robison, Isabel Mira-Avendano No Product/Research Disclosure Information