When Rheumatology Meets Pulmonology: Antisynthetase Syndrome

Abstract

SESSION TITLE: Pulmonary Manifestations of Systemic Disease 1 SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Antisynthetase syndrome is a rare autoimmune syndrome characterized by interstitial lung disease (ILD), inflammatory myositis, fevers, Raynaud’s phenomenon and polyarthralgia. Rarely, this syndrome can present as isolated ILD, with clinical features very similar to atypical pneumonia. CASE PRESENTATION: A 55-year-old female with no significant medical history presented with a dry cough for one month associated with decreased exercise tolerance, dyspnea on exertion, and bilateral chest pain. Physical examination revealed bibasilar “Velcro-like” dry inspiratory crackles and oxygen saturation of 95% on room air. Initial laboratory tests revealed microcytic anemia, C reactive protein 35.9 (0-3 mg/dL) and creatine kinase levels of 464 (21-215 units/L). Chest radiograph showed bibasilar airspace infiltrates more pronounced on the left. She was treated for community acquired pneumonia while Legionella and Mycoplasma pneumonia were ruled out. During her hospital course, she continued to desaturate to 80% upon exertion despite antibiotic treatment. Computed tomography of the chest showed extensive bilateral lower lobe opacities along with scattered ground glass opacities and peri-bronchial consolidations. Her gender, age, and radiological findings suspicious for ILD prompted a rheumatology workup, which was positive for rheumatoid factor, antinuclear antibody, cyclic citrullinated peptide, and anti-Jo-1 antibody. A subsequent right quadricep muscle biopsy revealed myositis. She was diagnosed with antisynthetase syndrome presenting primarily with ILD. The patient was started on pulse dose steroids along with mycophenolate mofetil (MMF) resulting in significant improvement. She was discharged home on tapering steroids, MMF, and oxygen supplementation with plans to start Rituximab along with close follow up. DISCUSSION: Initially described in 1990, antisynthetase syndrome was classified as a triad of polymyositis, ILD, and positive autoantibodies. Since then, rare case reports have identified ILD as the sole presentation for this syndrome. Autoantibodies are formed against eight aminoacyl-tRNA synthetases involved in recruiting antigen-presenting and inflammatory cells to sites of muscle or lung injury. Anti-Jo- 1 is the most common of these antibodies, seen in approximately 80% of these cases. High dose steroids are recommended for initial treatment and immunosuppressive agents and rituximab are used in patients with significant ILD. The prognosis of this syndrome is primarily based on the degree of ILD and its response to treatment. CONCLUSIONS: An alternative diagnosis must be entertained when standard therapy for pneumonia is unsuccessful. Although rare, early recognition and prompt treatment of antisynthetase syndrome can limit ILD progression and improve disease prognosis. Reference #1: Zamora AC et al. Clinical features and outcomes of interstitial lung disease in anti-Jo-1 positive antisynthetase syndrome. Respir Med. 2016 Sep;118:39-45. DISCLOSURE: The following authors have nothing to disclose: Robert Chao, Petros Efthimiou No Product/Research Disclosure Information