Casal-Dominguez M, Pinal-Fernandez I, Huapaya J, et al. - In this investigation, researchers studied muscle strength efficacy and corticosteroid tapering, as well as the prevalence of adverse effects in patients with the antisynthetase syndrome (ASyS) treated with azathioprine (AZA) vs those treated with methotrexate (MTX). Clinical outcomes were compared in ASyS patients treated with AZA vs MTX including change in corticosteroid dose, strength, and creatine kinase (CK) as well as the prevalence of adverse effects. Among 169 ASyS patients, 102 were treated with either AZA or MTX (± corticosteroids) exclusively at some point. No significant differences were found in the rate of muscle strength recovery, CK reduction or corticosteroid tapering between those ASyS patients treated with MTX vs AZA. In patients with ASyS, AZA and MTX exhibited comparable effectiveness and adverse events (elevated liver enzymes and gastrointestinal involvement). In patients receiving MTX, pneumonitis is a rare but important event.