CASE OF REFRACTORY INTERSTITIAL LUNG DISEASE IN ANTISYNTHETASE SYNDROME

Abstract

SESSION TITLE: Medical Student/Resident Diffuse Lung Disease SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Along with corticosteroids, patients with anti-synthetase syndrome associated interstitial lung disease (ILD) require a corticosteroid-sparing agent, such as azathioprine, rituximab, or cyclophosphamide. However, there is no study that demonstrates the superiority of one agent, making it difficult to choose one over the other given their high side effect profile. CASE PRESENTATION: A 67 years old female who had symptoms of left shoulder, arms, and eye pain that started 5 months ago, and dyspnea with exertion that started 7 months prior to presenting with worsening dyspnea. Initial work up was significant for elevated CK and aldolase, and positive ANA, anti Jo-1 and anti SS-A. CT was significant for NSIP pattern; and workup for infection was negative. Her initial oxygen requirement was 6 L. She was started on prednisone 60 mg daily, but her dyspnea progressed, getting into respiratory failure that required intubation. She was switched from prednisone to methylprednisolone 1 g/day for 3 days. She also received 2 doses of IV cyclophosphamide 1000 mg, followed by a total of 3 doses of IV Rituximab 700 mg that was initiated 8 days later. She was extubated 6 days later to facemask ventilation. She had frequent episodes of worsening dyspnea that occurred after a corticosteroid tapering attempt, therefore, requiring increased corticosteroids. She was eventually weaned to 2 liters of oxygen and discharged with home oxygen and a tapered dose of prednisone. DISCUSSION: Anti-synthetase syndrome is part of the idiopathic inflammatory myopathies (IIM) in which antibodies develop against aminoacyl tRNA. The diagnostic criteria for antisynthetase syndrome is the presence of tRNA synthetase autoantibody in addition to clinical features, such as ILD and/or myositis. The most commonly identified antibody is anti-Jo-1; other less common antibodies include: anti-PL12 and anti-PL7. ILD Anti-synthetase syndrome is more severe, rapidly progressing and leads to a high mortality when compared to ILD in the other IIMs. Corticosteroid-monotherapy in these patients is known to cause frequent lung disease reoccurrence. Therefore, an additional agent needs to be added in refractory cases. Azathioprine is a commonly used agent in conjunction with prednisone, but not well studied. Multiple other case studies showed improvement in lung function and/or pulmonary symptoms in patients who received Rituximab as the adjunctive medication. The treatment options that can be used in antisynthetase ILD lies at the discretion of the physician. In our case, the use of corticosteroids, Rituximab, and cyclophosphamide appeared to have significant clinical outcome. CONCLUSIONS: To better treat patients with this condition, high clinical suspicion is needed, and patients may benefit from early rituximab therapy. Future studies that compare the effect of corticosteroid-sparing agents would help on deciding the best treatment agents. Reference #1: Witt L., Curran J., Strek M. The Diagnosis and Treatment of Antisynthetase Syndrome. Clin Pulm Med. 2016 Sep; 23(5): 218-226. DISCLOSURES: no disclosure on file for Subramanyam Chittivelu; No relevant relationships by Ronald Espinosa, source=Web Response No relevant relationships by Abdirahman Hussein, source=Admin input