摘要：

目的 探讨血清抗乙酰胆碱受体（AChR）抗体、抗连接素（Titin）抗体和抗Ryanodine 受体（RyR）抗体对重症肌无力的诊断价值。方法 采用酶联免疫吸附试验分别检测182 例重症肌无力患者（MG 组）、105 例其他神经系统疾病患者（OND 组）和62 例正常对照者（对照组）血清抗AChR 抗体、抗Titin 抗体和抗RyR 抗体水平。结果 重症肌无力患者血清抗AChR 抗体、抗Titin 抗体和抗RyR 抗体阳性率分别为68.13%（124/182）、64.29%（117/182）和67.03%（122/182），高于OND 组（均P = 0.000）和对照组（均P = 0.000）；3 种血清学标志物同时阳性，诊断重症肌无力的灵敏度为41.21%，特异度达99.40%。其中，早发型与晚发型重症肌无力亚组血清抗AChR 抗体、抗Titin 抗体和抗RyR 抗体阳性率差异无统计学意义（均P > 0.05）；伴胸腺瘤的重症肌无力亚组仅血清抗AChR 抗体阳性率高于不伴胸腺瘤的重症肌无力亚组（P = 0.004），而抗Titin 抗体和抗RyR 抗体阳性率差异无统计学意义（均P > 0.05）；不同改良Osserman 分型亚组中仅全身型重症肌无力（Ⅱa 和Ⅱb 型）血清抗AChR 抗体阳性率高于眼肌型重症肌无力（Ⅰ型；P = 0.005，0.012），而抗Titin 抗体和抗RyR 抗体阳性率差异无统计学意义（均P > 0.05）。结论 血清抗AChR 抗体、抗Titin 抗体和抗RyR 抗体均有助于诊断重症肌无力，对于3 种生物学标志物同时呈阳性的患者，应高度怀疑重症肌无力，其中，眼肌型重症肌无力患者血清抗AChR 抗体水平较高，有可能进展为全身型重症肌无力，应积极治疗。

关键词: 重症肌无力, 受体, 胆碱能, 抗体, 酶联免疫吸附测定

Abstract:

Objective To investigate the expressions and clinical significance of serum anti - acetylcholine receptor antibodies (AChR-Ab), anti-Titin antibodies (Titin-Ab), and anti-Ryanodine receptor antibodies (RyR-Ab) in patients with myasthenia gravis (MG). Methods Serum AChR-Ab, Titin-Ab and RyR-Ab were detected with enzyme-linked immunosorbent assay (ELISA) in 182 MG patients, 105 patients of other neurological diseases (OND) and 62 normal controls. Results Serum AChR-Ab, Titin-Ab and RyR-Ab were detected positive respectively in 68.13% (124/182), 64.29% (117/182) and 67.03% (122/182) of patients in MG group. The positive rates of those antibodies in MG group were significantly higher than those in OND group (P = 0.000, for all) and control group (P = 0.000, for all). When 3 antibodies coexisted, the sensitivity in the diagnosis of MG was 41.21%, with 99.40% of specificity. There was no significant difference in the positive rate of serum AChR-Ab, Titin-Ab and RyR-Ab between early-onset MG subgroup and late-onset MG subgroup (P > 0.05, for all). The positive rates of AChR-Ab were significantly higher in MG patients with thymoma than in those without thymoma (P = 0.004). There was no significant difference in the positive rate of Titin-Ab and RyR-Ab between MG with thymoma subgroup and MG without thymoma subgroup (P > 0.05, for all). The prevalence of AChR-Ab in generalized MG (GMG) atients (Ⅱa and Ⅱb) was higher than those in ocular MG (OMG) patients (typeⅠ; P = 0.005, 0.012). There was no significant difference in the positive rate of Titin-Ab and RyR-Ab between GMG subgroup and OMG subgroup (P > 0.05, for all). Conclusions Serum AChR-Ab, Titin-Ab and RyR-Ab can be used as ndicators of the diagnosis of MG. Patients with 3 coexisted positive antibodies are highly suspected as MG. Higher AChR-Ab level in serum of OMG patients indicates the possibility of progressing to GMG.

Key words: Myasthenia gravis, Receptors, cholinergic, Antibodies, Enzyme - linked immunosorbent assay