Anti-HMGCR immune-mediated necrotizing myopathy: A case report.
- Author:
Yuan Jin ZHANG
1
;
Jing Yue MA
1
;
Xiang Yi LIU
1
;
Dan Feng ZHENG
2
;
Ying Shuang ZHANG
1
;
Xiao Gang LI
1
;
Dong Sheng FAN
1
Author Information
1. Department of Neurology, Peking University Third Hospital, Beijing 100191, China.
2. Department of Pathology, Peking University School of Basic Medical Sciences, Beijing 100191, China.
- Publication Type:Journal Article
- Keywords:
3-hydroxy-3-methylglutaryl-coenzyme areductase (HMGCR);
Antibody;
Autoimmune-mediated necrotizing myopathy
- MeSH:
Male;
Humans;
Middle Aged;
Autoantibodies;
Myositis/diagnosis*;
Autoimmune Diseases;
Muscle, Skeletal/pathology*;
Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use*;
Necrosis/pathology*;
Muscular Diseases/drug therapy*
- From:
Journal of Peking University(Health Sciences)
2023;55(3):558-562
- CountryChina
- Language:Chinese
-
Abstract:
The patient was a 55-year-old man who was admitted to hospital with "progressive myalgia and weakness for 4 months, and exacerbated for 1 month". Four months ago, he presented with persistent shoulder girdle myalgia and elevated creatine kinase (CK) at routine physical examination, which fluctuated from 1 271 to 2 963 U/L after discontinuation of statin treatment. Progressive myalgia and weakness worsened seriously to breath-holding and profuse sweating 1 month ago. The patient was post-operative for renal cancer, had previous diabetes mellitus and coronary artery disease medical history, had a stent implanted by percutaneous coronary intervention and was on long-term medication with aspirin, atorvastatin and metoprolol. Neurological examination showed pressure pain in the scapularis and pelvic girdle muscles, and V- grade muscle strength in the proximal extremities. Strongly positive of anti-HMGCR antibody was detected. Muscle magnetic resonance imaging (MRI) T2-weighted image and short time inversion recovery sequences (STIR) showed high signals in the right vastus lateralis and semimembranosus muscles. There was a small amount of myofibrillar degeneration and necrosis, CD4 positive inflammatory cells around the vessels and among myofibrils, MHC-Ⅰ infiltration, and multifocal lamellar deposition of C5b9 in non-necrotic myofibrils of the right quadriceps muscle pathological manifestation. According to the clinical manifestation, imageological change, increased CK, blood specific anti-HMGCR antibody and biopsy pathological immune-mediated evidence, the diagnosis of anti-HMGCR immune-mediated necrotizing myopathy was unequivocal. Methylprednisolone was administrated as 48 mg daily orally, and was reduced to medication discontinuation gradually. The patient's complaint of myalgia and breathlessness completely disappeared after 2 weeks, the weakness relief with no residual clinical symptoms 2 months later. Follow-up to date, there was no myalgia or weakness with slightly increasing CK rechecked. The case was a classical anti-HMGCR-IMNM without swallowing difficulties, joint symptoms, rash, lung symptoms, gastrointestinal symptoms, heart failure and Raynaud's phenomenon. The other clinical characters of the disease included CK as mean levels >10 times of upper limit of normal, active myogenic damage in electromyography, predominant edema and steatosis of gluteus and external rotator groups in T2WI and/or STIR at advanced disease phase except axial muscles. The symptoms may occasionally improve with discontinuation of statins, but glucocorticoids are usually required, and other treatments include a variety of immunosuppressive therapies such as methotrexate, rituximab and intravenous gammaglobulin.
