Antibodies against 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) have recently been associated with immune-mediated necrotizing myopathy, especially in patients with statin exposure. As the data are very limited concerning phenotypes and treatment in paediatric patients, this study aimed to identify the paediatric patients positive for anti-HMGCR antibodies and clarify their features and therapeutic strategies. Of 62 screend paediatric patients who were clinically and/or pathologically suspected to have inflammatory myopathy for anti-HMGCR antibodies, the authors identified nine paediatric patients with anti-HMGCR antibodies (15%). The onset age ranged from infancy to 13 years. Five patients were initially diagnosed with muscular dystrophy, including congenital muscular dystrophy. Most patients responded to high-dose corticosteroid therapy first but often needed adjuvant immunosuppressants to become stably controlled. These results suggest that autoantibody testing, including that for HMGCR, should be considered early for paediatric patients clinically and pathologically suspected to have not only necrotizing myopathy but also undiagnosed muscular dystrophy.
Liang WC, Uruha A, Suzuki S, et al. Pediatric necrotizing myopathy associated with anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibodies. Rheumatology (Oxford). 2016 Nov 6. pii: kew386. [Epub ahead of print]
