Case Presentation: A 41-year-old woman with a history of progressive ILD, Raynaud’s phenomenon, and Sjögren syndrome presented to ED for worsening dyspnea on exertion, malaise, fevers, chills, and body ache lasting more than 3 weeks. She had received treatment with antibiotics and a short course of steroids as an outpatient without effect. On physical exam, she had low-grade fever, tachycardia, tachypnea, and hypotension. Dry crackles were heard in the lower lobes bilaterally. The hyperkeratotic rash was noted on the palmar aspect of both hands. Laboratory work was remarkable for WBC of 31000/mcL and Hb of 8.9 g/dL. CT chest showed worsening pulmonary fibrosis, mediastinal lymphadenopathy. The patient was treated with broad-spectrum antibiotics. Her white blood cell count improved. However, she continued to have fevers ranging from 99 °F to 101.3 °F while being on scheduled Tylenol over a week of hospitalization. Shortness of breath and body aches persisted. All infectious workup including imaging, cultures, and viral panel was negative. Bronchoalveolar lavage showed normal cells. Rheumatologic workup showed CRP of 22, RF of 4. She was positive for anti-PL12 and anti-SSA-52 antibodies. Her CK and LDH were normal.Antisynthetase syndrome was diagnosed in the setting of ILD, fever, characteristic palmar rash, and positive anti-PL12. The patient was started on corticosteroids which helped with the fever. She was started on hydroxychloroquine and mycophenolate. She was discharged on 3 L of home oxygen and PFT later showed a restrictive pattern with FVC 0.99L. An option of a lung transplant was introduced to the patient.

Discussion: Antisynthetase syndrome (ASyS) is a spectrum of uncommon autoimmune diseases associated with antibodies to aminoacyl-t-RNA synthases (ARS). It was initially described as an acquired inflammatory myopathy associated with anti-Jo1 antibodies. We now know that only 78% of ASyS cases present with myositis and there have been eight ARS antibodies identified to date. anti-Jo-1 is the most prevalent, comprising two-thirds of identified ARS antibodies. Others are less frequent and include anti-PL-12, anti-PL-7, anti-OJ, anti-EJ, anti-asparaginyl-tRNA synthetase, anti-phenylalanyl-tRNA synthetase and anti-tyrosyl tRNA synthetase. Clinical presentation varies including myositis, interstitial lung disease (ILD), arthritis, cutaneous hyperkeratosis, mechanic’s hands, fever and Raynaud’s phenomenon. Our case is an example of ASyS diagnosed in a setting of fever of unknown origin (FUO) in an acute setting, though the disease manifested years prior with ILD. Fortunately patient had rheumatologic testing that uncovered ASyS and the patient was started on targeted treatment. Literature overview shows that ASyS is frequently found months to years after the initial presentation which delays definitive treatment and worsens prognosis particularly if the disease manifests with ILD.Our patient was positive for anti-PL12 and anti-SSA-52 which is not a frequent combination. Additionally, only one case of AsyS association with Sjögren syndrome was found in the literature.

Conclusions: 1. Rheumatologic workup is beneficial for patients meeting FUO criteria when more common causes are excluded.2. Early broad rheumatologic workup is beneficial for patients with ILD. 3. ASyS may be also associated with Sjögren syndrome-like picture.