Immune Myopathy with Perimysial Pathology Associated with Interstitial Lung Disease and Anti-EJ Antibodies

OBJECTIVES: We report a case of immune myopathy with perimysial pathology associated with anti-glycyl-transfer RNA synthetase (anti-EJ) antibody and an excellent treatment response. METHODS: Chart review. RESULTS: A 36-year-old woman presented with 3 months of fatigue, weight loss, progressive weakness in a scapuloperoneal distribution, and dysphagia. Nerve conduction studies, electromyography, and ultrasound suggested an irritable myopathy. She had marked elevations of creatine kinase and positive anti-glycyl-transfer RNA synthetase (anti-EJ) antibodies. A left biceps muscle biopsy revealed inflammation of the perimysium and surrounding perimysial blood vessels with focal fragmentation of the perimysium. Further evaluation revealed interstitial lung disease. Treatment with prednisone and mycophenolate mofetil led to marked clinical improvement of her symptoms. CONCLUSIONS: Our case adds to the growing spectrum of inflammatory myopathies and highlights the importance of performing a comprehensive, multisystem workup.