重症肌无力患者血清Ryanodine受体抗体与临床的相关性研究

目的 探讨血清Ryanodine受体抗体(RyR-Ab)与重症肌无力(MG)的关系.方法 应用ELISA和Western blot法分别检测81例MG患者、45例非MG神经系统其他疾病(NMG)患者和50例健康对照者(HC)血清中RyR-Ab水平.结果 ELISA法显示:MG组RyR-Ab阳性率为23.4%.明显高于HC组和NMG组(均为阴性),差异有统计学意义(P<0.05);MG伴胸腺瘤(MGT)组阳性率最高(77.2%),MG伴胸腺萎缩(MGA)者次之(14.2%),MG伴胸腺增生(MGH)者为6.6%;而且RyR-Ab水平与肌无力的严重程度成正相关(r=0.547.P<0.05);RyR-Ab诊断MGT的敏感性(77.2%)低于胸腺CT(88.2%),但特异性(91%)高于后者(72.2%),差异有统计学意义(P<0.05).Westemblot法显示:MGT组RyR-Ab阳性条带检出率最高(81.8%),明显高于非胸腺瘤MG(NTMG)组(4.5%)和NMG组(0),差异有统计学意义(P<0.05).结论 RyR-Ab阳性多见于MGT,检测RyR-Ab可以弥补影像学的不足,有助于诊断MGT和评估病情.

Clinical value of serum level of ryanodine receptor antibodies in diagnosis of myasthenia gravis

Objective To investigate the clinical value of detecting the serum level of ryanodine receptor antibodies (RyR-Ab) in the diagnosis and evaluation of myasthenia gravis (MG). Methods Enzyme-linked immunosorbent assay (ELISA) and Western blotting were used to detect the serum level of RyR-Ab in 81 patients with MG, 45 non-MG patients with other neurological disorders and 50 healthy control subjects. Results The results of ELISA showed a serum RyR-Ab positivity rate of 23.4% in the in MG patients, significantly higher than the rates in non-MG patients and the healthy subjects (P<0.05). The serum RyR-Ab positivity rate was 77.2% in MG patients with thymoma (MGT), 14.2% in those with thymie atrophy (MGA), and 6.6% in those with thymie hyperplasia (MGH). A positive correlation was found between the titer of serum RyR-Ab and the severity of muscle weakness (r=0.547, P<0.05). Compared with CT scanning, serum RyR-Ab level had low sensitivity (77.2%) but high specificity (91%, P<0.05) for diagnosis of MGT. According to the results of Western blotting, the serum RyR-Ab positivity rate was 81.8% in MGT patients, significantly higher than that in thymomβ-free MG patients and NMG patients (P<0.05). Conclusion RyR-Ab positivity is mainly found in MGT patients, and detection of serum RyR-Ab may help evaluate the severity of MG and assist in CT-based diagnosis of MGT.