Clinical characteristics in antibody-positive pediatric patients with immune-mediated necrotizing myopathy

作者：Yiwen Xu, Z. Zhang, Yixuan Chu, Fang He, Leilei Mao, Li Yang, Li Yang, Fei Yin, Jing Peng, Lifen Yang, Lifen Yang, Ciliu Zhang · 发表于：˜The œItalian Journal of Pediatrics/Italian journal of pediatrics · 年份：2026 · DOI：10.1186/s13052-026-02278-7 · 研究领域：Inflammatory Myopathies and Dermatomyositis、Parkinson's Disease and Spinal Disorders、Viral Infections and Immunology Research

OBJECTIVE: To investigate the clinical characteristics and therapeutic strategies of childhood immune-mediated necrotizing myopathy (IMNM) and to provide evidence for clinical diagnosis and management. METHODS: This single-center retrospective study analyzed the clinical data of 10 children diagnosed with antibody-positive IMNM at the Children's Medical Center, Xiangya Hospital, Central South University, from January 2016 to May 2025. The onset features, clinical manifestations, laboratory findings, muscle magnetic resonance imaging (MRI) characteristics, treatment modalities, and prognosis were summarized. RESULTS: Among the 10 patients, 4 were male and 6 were female, with a median age at onset of 5.5 years (range: 3-16 years). The main clinical manifestations included symmetric proximal muscle weakness (100%) and cutaneous manifestations (50%, including Gottron's sign and periorbital rash). Creatine kinase (CK) levels were markedly elevated, with a median of 3988.5 U/L (range: 2080-13524 U/L). Muscle MRI revealed edema or fatty infiltration in the thigh muscles. Anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibodies were detected in 4 patients (40%), and anti-signal recognition particle (SRP) antibodies in 6 patients (60%). Electromyography (EMG) showed myopathic changes in all tested cases (8/10 patients). Muscle histopathology was available for one patient, demonstrating myofiber necrosis, regeneration, and inflammatory cell infiltration. All patients rec...