Analysis of clinical characteristics and treatment of pediatric anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibody-positive myopathy
10.3760/cma.j.cn101070-20200824-01402
- VernacularTitle:儿童抗3-羟基-3-甲基戊二酰-辅酶A还原酶抗体肌病临床特点和治疗分析
- Author:
Zhiqiang LUO
1
;
Jianxiang LIAO
Author Information
1. 深圳市儿童医院神经内科，深圳 518038
- Keywords:
Child;
Anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase antibody-positive myopathy;
Immune-mediated necrotizing myopathy;
Clinical characteristic;
Tre
- From:
Chinese Journal of Applied Clinical Pediatrics
2022;37(2):139-142
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To explore clinical characteristics and treatment of pediatric anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibody-positive myopathy.Methods:Two cases of pediatric anti-HMGCR antibody-positive myopathy admitted to the Department of Neurology, Shenzhen Children′s Hospital from January to July 2020 were retrospectively analyzed for their clinical manifestations, creatine kinase (CK), myositis autoantibody, electromyography (EMG), muscle pathology, muscle magnetic resonance imaging (MRI), and treatment information.Results:Both of them were female cases.Case 1 was 3 years and 11 months old and case 2 was 7 years and 9 months old.They used to be healthy without history of statin use.Case 1 showed chronic onset of the disease, and case 2 had a subacute onset.The main clinical manifestations were progressive symmetric proximal muscle weakness accompanied by myalgia.Case 1 developed skin rash but case 2 did not.Significantly increased CK level was detected in both of them, which increased by 27.3-48.0 and 66.7-77.4 times of the upper limit before treatment in case 1 and case 2, respectively.They were diagnosed as muscular dystrophy at the early stage.EMG results suggested myogenic injuries in 2 cases, and muscle MRI showed extensive muscle edema.The muscle pathology of the 2 cases suggested muscle necrosis with a small amount of inflammatory cell infiltration.After diagnosis, both of them were treated with Methylprednisolone combined with intravenous immunoglobulin.CK decreased significantly but remained high, and muscle weakness was improved but did not return to normal.Oral Prednisone was given after discharge and case 2 was additionally medicated with azathioprine.Conclusions:Compared with adult patients, the clinical characteristics of pediatric anti-HMGCR antibody-positive myopathy are mostly similar.However, children patients usually have no history of statins and are more difficult to treat, less effective and worse prognosis.In addition, children patients are more likely to be diagnosed with " muscular dystrophy" at the beginning of illness.Therefore, idiopathic myositis autoantibody should be examined to confirm the diagnosis for children suspected to be " muscular dystrophy" but not confirmed by genetic examination.
