Introduction
Antisynthetase syndrome is a constellation of “mechanic’s hands,” interstitial lung disease (70%), myositis, arthritis (50%), rash (30%), sicca syndrome, Raynaud’s phenomenon and constitutional symptoms.1-3 Antibodies are produced to aminoacyl tRNA synthetases that catalyze attachment of amino acids to tRNA and recruit inflammatory cells to sites of muscle and lung injury.1 In EJ-antibody antisynthetase syndrome, the antigen is glycyl tRNA synthetase (GARS).2
Eight anti-aminoacyl-tRNA synthetases (ARS) have been described; anti-EJ comprise 2-5%.3 Myositis is a late manifestation at 17 months.2 EMG, muscle MRI and biopsy show steroid-responsive myopathy.3 Long term immunosuppression is required 80% of the time.4