Antisynthetase Syndrome With Predominant Pulmonary Involvement: A Case Report.

Antisynthetase syndrome (ASyS) is an autoimmune disease characterized by the presence of aminoacyl-transfer RNA synthetase antibodies. Its clinical presentation is variable and may include interstitial lung disease (ILD), myositis, arthritis, fever, Raynaud's phenomenon, and "mechanic's hands." ILD is more prevalent in this entity when compared to other idiopathic inflammatory myopathies and imparts greater severity to the condition. Here, we report the case of a 42-year-old female patient who sought care for severe ILD and persistent fever. Her diagnosis was made only after the detection of anti-Jo1 autoantibodies. Treatment was refractory to both prednisone monotherapy and cyclophosphamide pulse therapy, requiring the introduction of rituximab. A high degree of clinical suspicion is required to allow early diagnosis of ASyS in patients with pulmonary involvement in the absence of accompanying muscle weakness or other clinical symptoms.