Case report: Antisynthetase syndrome with positive anti-PL7/SSA/RO52 antibodies

Background: Antisynthetase syndrome (ASS) is a rare autoimmune disease characterized by the immune system attacking specific synthetase in the body. Due to the difficulty in clinical diagnosis, there is still a lack of effective treatment. Methods: We report a case of a 50-year-old man who presented with progressive, symmetric limb weakness, starting from the lower limbs and gradually affecting the upper limbs. He was admitted to the intensive care unit (ICU) for treatment due to recurrent fever and coma. When he was admitted to the ICU, his limbs were almost unable to move, and the levels of creatine phosphokinase and muscle glycogen were significantly elevated (2449 u/l and 1857 ng/ml). The electromyogram showed myogenic injury, and the anti-PL7 antibody, anti-SSA antibody, and anti-Ro52 antibody were positive. Pathological biopsy of the left biceps brachii showed striated muscle necrosis and macrophage infiltration. He was finally diagnosed with ASS and received treatment with methylprednisolone (subsequently changed to prednisone) and traditional Chinese medicine (Buzhongyiqi Decoction and Shenlingbaizhu powder). Results: After receiving 2 weeks of glucocorticoid and traditional Chinese medicine treatment, his muscle strength had basically recovered, reaching grade 5 in his limb muscles strength. During the 3-month follow-up period, his activity tolerance continued to improve. Conclusion: We present a case of severe anti-PL7 positive ASS with positive anti-SSA/Ro52 antibody. The disease was relieved by glucocorticoid and traditional Chinese medicine treatment. This provides an effective approach for managing ASS.