The Diagnosis and Treatment of Antisynthetase Syndrome

Abstract

Anti-synthetase syndrome is an autoimmune condition, characterized by antibodies directed against an aminoacycl transfer RNA synthetase along with clinical features that can include interstitial lung disease, myositis, Raynaud's phenomenon, and arthritis. There is a higher prevalence and increased severity of interstitial lung disease in patients with anti-synthetase syndrome, as compared to dermatomyositis and polymyositis, inflammatory myopathies with which it may overlap phenotypically. Diagnosis is made by a multidisciplinary approach, synthesizing rheumatology and pulmonary evaluations, along with serologic, radiographic, and occasionally muscle and/or lung biopsy results. Patients with anti-synthetase syndrome often require multi-modality immunosuppressive therapy in order to control the muscle and/or pulmonary manifestations of their disease. The long-term care of these patients mandates careful attention to the adverse effects and complications of chronic immunosuppressive therapy, as well as disease-related sequelae that can include progressive interstitial lung disease necessitating lung transplantation, pulmonary hypertension, malignancy and decreased survival. It is hoped that greater awareness of the clinical features of this syndrome will allow for earlier diagnosis and appropriate treatment to improve outcomes in patients with anti-synthetase syndrome.

Figure 1. High-resolution CT in anti-synthetase syndrome at presentation

48 year-old woman with Jo-1 positive anti-synthetase antibody syndrome, presented with acute respiratory distress syndrome. HRCT reveals bilateral, diffuse groundglass opacities.

Figure 2. High-resolution CT anti-synthetase syndrome after treatment

The same patient eleven days after treatment with IV cyclophosphamide and high-dose corticosteroids. Tacrolimus was also initiated. The cyclophosphamide was subsequently switched to azathioprine after discharge from the hospital. Lung function normalized despite tapering off prednisone. Lung disease relapsed when patient self-discontinued tacrolimus. She is now back in remission on a prednisone taper, azathioprine and tacrolimus.