目的 分析幼年型皮肌炎（juvenile dermatomyositis, JDM）中肌炎特异性抗体（myosositis-specific antibody, MSA）的分布情况，并探讨其与JDM临床特征的关系。 方法 回顾性分析2020年1月—2025年4月收治的72例JDM患儿临床资料，所有患儿均行肌炎抗体检测，分析常见MSA亚型与JDM患儿临床特征的关系。 结果 72例JDM患儿中，MSA阳性45例（62%），其中抗NXP2抗体阳性27例（38%），抗MDA5抗体阳性10例（14%），抗cN1A抗体阳性3例（4%）。抗MDA5抗体阳性患儿发热、关节炎/关节痛、间质性肺病发生率高于MSA阴性患儿（P<0.05）。抗NXP2抗体阳性患儿皮下钙质沉着症、发热、软组织水肿、间质性肺病发生率高于MSA阴性患儿（P<0.05）。抗NXP2抗体阳性患儿的肌酸激酶和肌酸激酶同工酶水平高于抗MDA5抗体阳性和MSA阴性患儿（P<0.017），儿童肌炎评估量表评分低于抗MDA5抗体阳性和MSA阴性患儿（P<0.017）。 结论 JDM患儿MSA阳性率较高，不同MSA亚型与特定临床特征及脏器受累相关，开展MSA检测对疾病诊治具有重要意义。

Objective To investigate the distribution of myositis-specific antibodies (MSA) in juvenile dermatomyositis (JDM) and the relationship between MSA and clinical features of JDM. Methods Clinical data of 72 children with JDM hospitalized from January 2020 to April 2025 were reviewed retrospectively, all of whom had been tested for MSA. The relationship between common MSA subtypes and clinical features was analyzed. Results Among the 72 children, 45 (62%) were positive for MSA, including 27 anti-NXP2-positive cases (38%), 10 anti-MDA5-positive cases (14%), and 3 anti-cN1A-positive cases (4%). Compared with the MSA-negative group, the anti-MDA5-positive patients showed significantly higher incidence rates of fever, arthritis, and interstitial lung disease (P<0.05). The anti-NXP2-positive patients exhibited significantly higher incidence rates of calcinosis, fever, soft tissue edema, and interstitial lung disease than the MSA-negative patients (P<0.05). Compared with the anti-MDA5-positive group and MSA-negative group, the anti-NXP2-positive group had significantly higher levels of creatine kinase and creatine kinase isoenzyme (P<0.017) and a significantly lower score of the Childhood Myositis Assessment Scale (P<0.017). Conclusions The positive rate of MSA is high in children with JDM, with different subtypes correlating with specific clinical manifestations and organ involvement. Detection of MSA is crucial for diagnosis and clinical management of JDM.