抗信号识别颗粒抗体阳性肌病的临床特点并文献复习

Clinical characteristics and literature review of myopathy with positive anti-signal recognition particle antibody

目的探讨抗信号识别颗粒(signal recognition particle,SRP)抗体阳性肌病的临床特点。方法对4例抗SRP抗体阳性肌病患者的临床资料、辅助检查及诊疗经过进行回顾性分析。结果4例患者有起病方式各异,部分慢性起病。主要表现为近端为著的肢体无力及吞咽困难,血肌酸激酶均显著升高,血清中抗SRP抗体阳性。肌电图提示肌源性损害,也可合并部分神经源性损害表现。部分合并心肌酶及转氨酶的升高。肌肉活检表现为骨骼肌纤维的变性、坏死和再生。肥大、萎缩肌纤维可累及两型。炎性细胞可以出现,以巨噬细胞为主,少量淋巴细胞浸润。主要组织相容性复合体1型抗原(MHC-I)染色弥漫性阳性或弱阳性表达,膜攻击复合物(C5b-9)染色可见坏死肌纤维补体沉积。结论抗SRP抗体阳性肌病是免疫介导性坏死性肌病中的一种重要类型,临床表现多样,主要依靠血液中抗SRP抗体检测及肌肉的病理进行诊断。如果能早期明确,给予早期足量和长期有效维持量的药物治疗,能改善预后。

Objective To investigate the clinical characteristics of myopathy with positive anti-signal recognition particle(SRP)antibody.Methods The clinical data,laboratory examination,diagnosis and treatment of 4 patients with anti-SRP antibody positive myopathy were retrospectively analyzed.Results Four patients had different onset modes and could have chronic onset.The main manifestations were proximal limb weakness and dysphagia,significantly increased serum creatine kinase and positive serum anti-SRP antibody.Electromyography(EMG)suggested myogenic damage,but may also be accompanied by some neurogenic damage.Myocardial enzyme and transaminase elevated in some patients.Muscle pathology showed degeneration,necrosis,and regeneration of skeletal muscle fibers.Hypertrophic and atrophic muscle fibers were involved in both types.Inflammatory cells may be present,mainly macrophages,with a small infiltration of lymphocytes.Expression of major histocompatibility complex class 1(MHC-I)was diffusely positive or weakly positive,and membrane attack complex(C5b-9)staining showed complement deposition of necrotic muscle fibers.Conclusion Anti-SRP antibody positive myopathy is an important type of immune-mediated necrotizing myopathy with a variety of clinical manifestations.The diagnosis mainly depends on the detection of anti-SRP antibody in blood and muscle pathology.If it can be identified early,the administration of early sufficient dose and long-term effective maintenance dose of drug therapy can improve the prognosis.