Clinical and Radiological Features of Korean Patients With Anti-HMGCR Myopathy

• Published in: Journal of clinical neurology (Seoul, Korea) 2023, 19(5), , pp.460-468
• Main Authors: Oh, Eun Kyoung, Lee, Seung-Ah, Lee, Hyun Joon, Cha, Yoon Jin, Kim, Sungjun, Lee, Hyung-Soo, Suh, Bum Chun, Shin, Ha Young, Kim, Seung Woo, Yoon, Byeol-A, Oh, Seong-Il, Kim, Yoo Hwan, Cho, Joong-Yang, Cho, Jeong Hee, Kwon, Ki-Han, Choi, Young-Chul, Park, Hyung Jun
• Format: Article
• Language: English
• Subjects: Original; 신경과학
• ISSN: 1738-6586; 2005-5013
• DOI: 10.3988/jcn.2022.0374

To understand the characteristics of Korean patients with anti-3-hydroxy-3-methylglutaryl-coenxyme A reductase (HMGCR) myopathy, we measured anti-HMGCR antibodies and analyzed the clinical, radiological, and pathological features of patients with anti-HMGCR myopathy. We measured titers of anti-HMGCR antibodies in the sera of 99 patients with inflammatory myopathy, 36 patients with genetic myopathy, and 63 healthy subjects using an enzyme-linked immunosorbent assay. We tested 16 myositis-specific autoantibodies (MSAs) in all patients with anti-HMGCR myopathy. Positivity for the anti-HMGCR antibody was observed in 17 (4 males and 13 females) of 99 patients with inflammatory myopathy. The median age at symptom onset was 60 years. Ten (59%) of the patients with anti-HMGCR positivity had taken statins. The titer of anti-HMGCR antibodies was significantly higher in the statin-naïve group (median=230 U/mL, interquartile range=170-443 U/mL) than in the statin-exposed group (median=178 U/mL, interquartile range=105-210 U/mL, =0.045). The most common symptom was proximal muscle weakness in 15 patients (88%), followed by myalgia in 9 (53%), neck weakness in 4 (24%), dysphagia in 3 (18%), and skin lesions in 2 (12%). The median titer of anti-HMGCR antibody was 202 U/mL. We found eight different MSAs in nine (53%) patients. The median disease duration from symptom onset to diagnosis was significantly shorter in the MSA-positive group than in the MSA-negative group ( =0.027). Our study was the first to measure anti-HMGCR antibodies in inflammatory myopathy. It has provided new findings, including the suggestion of the coexistence of other MSAs in Korean patients.