肌炎抗体在特发性炎性肌肉病中的诊断价值

The research of myositis antibodies in idiopathic inflammatory muscle disease

目的探讨肌炎抗体在炎性肌肉病诊断和鉴别诊断中的作用。方法应用免疫印迹法对2010-01-2012-04于作者医院门诊就诊的101例患者进行血清肌炎抗体谱的检测,同时行肌肉活检,进行常规组织学、酶组织化学和免疫组织化学染色。结果 101例患者中经肌肉活检确诊炎性肌肉病50例和非炎性肌肉病51例。在炎性肌肉病患者中肌炎特异性抗体(myositis-specific antibodies,MSAs)阳性者13例(26.0%),肌炎相关性抗体(myositis-associated antibodies,MAAs)阳性者22例(44.0%)。在非炎性肌肉病患者中MSAs阳性者1例(2.0%),MAAs阳性者8例(15.7%)。MSAs的敏感性和特异性分别为26.0%和98.0%,MAAs的敏感性和特异性分别为56.0%和84.3%。所有肌炎抗体阳性的患者中抗SRP抗体的阳性者所占的比例为31.4%,抗Jo-1、Mi-2、Ro-52、Pm/scl-75、Ku抗体阳性者所占的比例分别为5.7%、2.9%、68.6%、20.0%、2.9%。结论在炎性肌肉病患者中,MSAs特异性高而敏感性较低,MAAs敏感性高特异性相对较低,二者结合有助于不同类型炎性肌肉病的诊断及与其他肌肉病如代谢性肌肉病和肌营养不良的鉴别诊断,对临床疑诊炎性肌肉病的患者应该进行肌炎抗体的筛查,特别是应对坏死性肌病患者进行抗SRP抗体的检测。

Objective To discuss the value of myositis antibodies tested by immunoblotting assay in the diagnosis and differential diagnosis of idiopathic inflammatory muscle disease.Methods Serum myositis antibody profiles were tested by immunoblotting assay for the 101 patients with muscle diseases from January 2010 to April 2012; muscle biopsies were performed in all of them and the specimens were examined with standard histological,enzyme histochemistrical,immunohistochemical methods.Results There were 50 patients with inflammatory muscle disease,including 13 MSAs-positive cases （26.0％） and 22 MAAs-positive cases （44.0％）.There were 51 patients with non-inflammatory muscle disease,including 1 MSAs-positive case （2.0％） and 8 MAAs-positive cases （15.7％）.The sensitivity and specificity of the MSAs were 26.0％ and 98.0％ respectively while the MAAs were 56.0％ and 84.3％.In all the patients who had positive myositis antibodies,the positive rate was 31.4％ for anti-SRP antibody,and 5.7 ％,2.9 ％,68.6 ％,20.0 ％,2.9 ％ for Jo-1,Mi-2,Ro-52,Pm/scl-75,Ku antibodies respectively.Conclusions In the patients with inflammatory muscle disease,the MSAs are of high specificity but low sensitivity while the MAAs are of high sensitivity but low specificity,so the detection of the miyositis antibodies will contribute to the diagnosis of idiopathic inflammatory muscle disease and the differential diagnosis of idiopathic inflammatory muscle disease from other myopathies such as metabolic myopathies and muscular dystrophy.The serum myositis antibodies should be screened in the patients with clinically suspected inflammatory muscle disease,specially patients with suspected autoimmune necrotizing myopathy should carry out the detection of anti-SRP antibodies.