Coexistence of two antisynthetases in a patient with the antisynthetase syndrome

Abstract

We describe the immunologic findings in a patient with the antisynthetase syndrome characterized by prominent arthritis, lung fibrosis, and subclinical myositis. At disease onset and during the followup, this patient's serum showed 2 different subsets of antisynthetase autoantibodies: anti–Jo‐1, which reacted with histidyl–transfer RNA (tRNA) synthetase by immunoblot and inhibited its enzymatic function; and anti‐OJ, which immunoprecipitated the multi‐enzyme complex of synthetases, and reacted with lysyl‐tRNA synthetase by immunoblot. This is the first report of anti–Jo‐1 and another antisynthetase antibody being found together in the same patient.