Early Recognition and Successful Treatment of Anti-synthetase Syndrome

Anti-synthetase syndrome is an autoimmune disorder that is characterized by inflammatory myopathy, non-erosive polyarthritis, interstitial lung disease in addition to the presence of anti-aminoacyl t-RNA synthetase antibody. It can have variable presentations posing a major diagnostic challenge. Recognition of this syndrome is crucial for appropriate, timely therapy to prevent morbidity and mortality. We report the case of a 55-year-old male who initially presented to the emergency department (ED) with sudden onset shortness of breath, low-grade fever, dry cough, fatigue, and severe arthralgia. He was diagnosed with community-acquired pneumonia and was discharged with antibiotics. He then presented to his primary care physician (PCP) with worsening symptoms. A computed tomography (CT) scan of the chest showed the presence of patchy bilateral airspace opacities and infiltrates. He had elevated inflammatory markers and anti-nuclear antibodies (ANAs). Pulmonary function test (PFT) showed a restrictive pattern with a reduction in lung volumes. Further workup revealed the presence of anti-Jo-1 antibodies. In addition, a muscle biopsy was obtained which showed inflammatory myopathy. Lung biopsy was consistent with interstitial fibrosis. The diagnosis of the anti-synthetase syndrome was made and the patient was promptly started on high-dose prednisone and cyclophosphamide which was later switched to azathioprine and tacrolimus due to resistance and side effects. The patient's symptoms improved significantly with the current treatment without any other complications. This case highlights the importance of a thorough history and physical exam by PCP. Prompt communication and care coordination between PCP and specialists (rheumatologist and pulmonologist) are essential to expedite diagnostic testing and initiate treatment early in this disorder.