Anti-Ha Antisynthetase Syndrome: A Case Report.

Anti-synthetase syndrome (ASyS) is a rare systemic autoimmune myopathy characterized by the involvement of muscles, lungs, and joints, in addition to Raynaud's phenomenon, "mechanics' hand," and fever. Laboratory ASyS is defined by the positivity of anti-aminoacyl-tRNA synthetase autoantibodies, of which anti-Jo-1 is the most common. Herein, we reported an ASyS defined by an anti-Ha autoantibody, which has rarely been described in the literature. Moreover, to the best of our knowledge, we reported the first case of anti-Ha ASyS in Brazil.