Anti-Ro52-positive antisynthetase syndrome (ASS): a case report and review of the literature.

Background: This study aimed to diagnose and treat a patient with anti-Ro52-positive antisynthetase syndrome (ASS), investigate the association between anti-Ro52 antibodies and ASS, and determine its clinical significance. The objective of this clinical report is to highlight this unusual syndrome to avoid incorrect diagnosis. Case Description: A middle-aged woman presenting with obvious lung symptoms was admitted to our hospital. A physical examination revealed swollen joints in both hands, mechanic's hands, and normal muscle strength and muscle tone in all 4 extremities. A myositis-specific antibody panel, lung computed tomographic (CT) imaging, electromyography, and muscle biopsy were performed as auxiliary examinations, and appropriate treatment was administered after the confirmed diagnosis. The myositis-specific antibody panel yielded strongly positive results for anti-Jo-1 and anti-Ro52 antibodies, lung CT imaging revealed interstitial lung disease, electromyography revealed myogenic damage, and muscle magnetic resonance imaging revealed multiple inflammatory exudates. A definitive diagnosis of ASS was made, and glucocorticoid and immunosuppressant therapy were administered. After treatment, the patient's symptoms were alleviated, creatine kinase activity was reduced, and signs of disease activity and secondary tumors were not observed on a subsequent follow-up evaluation. Conclusions: Anti-Ro52 antibodies, being myositis-associated antibodies, can lead to an atypical clinical presentation in ASS patients and are potentially associated with a poor prognosis. Therefore, thorough follow-up evaluation is required for such cases.