Antisynthetase Syndrome

Autoantibodies to many of the aminoacyl-transfer RNA synthetases have been identified, the most common of which is directed at histidyl-tRNA synthetase (anti-Jo-1). Most individual patients have AuAbs to only one of these enzymes, but each autoantibody has been associated with a similar set of clinical manifestations including inflammatory myopathy, interstitial lung disease, arthritis, Raynaud’s phenomenon, and mechanic’s hands. The antisynthetases were first recognized as myositis, autoantibodies, and myositis is present in over 95% of anti-Jo-1 patients in most studies, but some patients have interstitial lung disease, or occasionally arthritis, without myositis, particularly those with certain of the non-Jo-1 antisynthetases. Clinically similar myositis and other connective tissue disease features can occur in association with other autoantibodies, but when associated with an antisynthetase autoantibody, it has been referred to as the antisynthetase syndrome. Patients often do not have all features of the syndrome. Although there are no defined criteria for this condition, patients with two major clinical features along with the autoantibody could reasonably be considered to have the syndrome. Identifying patients as having antisynthetases may be helpful in diagnosis, patient characterization, and patient management.