Coexistence of two antisynthetases in a patient with the antisynthetase syndrome



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.