SESSION TITLE: Medical Student/Resident Diffuse Lung Disease SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Antisynthetase syndrome (ASS) is a rare autoimmune condition characterized by antibodies directed against amino-acyl-tRNA synthetase along with clinical features of myositis, arthritis, Raynaud’s phenomenon and interstitial lung disease (ILD). We present a case of rapidly progressive ASS associated ILD. CASE PRESENTATION: A 40-year-old African American woman with past medical history of smoking and prior hospitalization for presumed pneumonia presented to the emergency department with complaints of ongoing but worsening cough and dyspnea for more than four months. She was hypoxic and lung examination revealed bilateral fine crackles. Chest imaging revealed patchy mixed consolidation and ground-glass opacities at the lung bases (figure 1). Her course worsened needing mechanical ventilation. Given the clinical picture and imaging findings raising concerns for ILD, she underwent VATS/lung biopsy, which revealed pinkish fibrous plugs: Masson bodies, concerning for organizing pneumonia (figure 2). Autoimmune work including ANA and rheumatoid factor was negative. She continued to decline despite broad-spectrum antibiotics and high dose steroids and had to be placed on VV-ECMO for severe ARDS. Hyperkeratosis and hyperpigmentation of her hands were later noted, raising concerns for an autoimmune process. A myositis panel was done, which revealed positive Anti-PL12 antibodies. Lung function recovery was sub-optimal despite ECMO support for 85 days, IVIG, plasma exchange and cyclophosphamide therapy. She had to undergo single left lung transplantation. She eventually was discharged home on immunosuppressants after five months of hospitalization. Her explanted lung showed features of non-specific interstitial pneumonia. She has done well for more than 2 years post-transplant with amelioration in the imaging findings of her native right lung and with no signs of graft rejection. The final diagnosis was rapidly progressive ASS associated ILD with progression to ARDS requiring single lung transplantation. DISCUSSION: ASS is a rare group of idiopathic inflammatory myopathies, characterized by the presence of seven different myositis-specific antisynthetase antibodies with Anti-Jo1 being the most common one. Anti-PL12 antibody type is associated with a severe form of ILD. ANA antibodies are typically negative and hence a high index of suspicion for ASS is warranted. Literature about the management of ASS-ILD is sparse but anecdotal experience favors steroids as first-choice agents and other immunosuppressive agents, plasma exchange therapy, and even lung transplantation in severe and refractory cases. CONCLUSIONS: Our case of ASS-ILD with anti-PL12 antibodies shows the rapid progression of the ILD despite aggressive immunosuppressive therapy and highlights the importance of identification, aggressive therapy and the role of VV-ECMO with lung transplantation as an option for refractory cases. Reference #1: Connors GR, Christopher-Stine L, Oddis CV, et al. Interstitial lung disease associated with the idiopathic inflammatory myopathies: what progress has been made in the past 35 years? Chest. 2010;138:1464–1474. Reference #2: Esposito AC, Gige TC, Miot HA. Syndrome in question: antisynthetase syndrome (anti-PL-7). An Bras Dermatol. 2016;91(5):683-685. DOI:10.1590/abd1806-4841.20164449 Reference #3: Witt LJ, Curran JJ, Strek ME. The Diagnosis and Treatment of Antisynthetase Syndrome. Clin Pulm Med. 2016;23(5):218-226. DOI:10.1097/CPM.0000000000000171 DISCLOSURES: No relevant relationships by Anas Alameh, source=Web Response No relevant relationships by Ansaam Daoud, source=Web Response No relevant relationships by Sujith Modugula, source=Web Response No relevant relationships by Lokesh Venkateshaiah, source=Web Response No relevant relationships by Elizabeth Verghese, source=Web Response