Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, England, UK.
J Neurol Sci. 2011 Feb 15;301(1-2):71-6. doi: 10.1016/j.jns.2010.10.023. Epub 2010 Dec 4.
To establish non-radioactive assays for detection of antibodies (Abs) to the acetylcholine receptor (AChR) and to muscle specific kinase (MuSK). To show that the assays can be used in Tianjin for testing patients with MG.
AChR and MuSK Abs in 51 Chinese MG patients' sera were tested in Oxford, UK, using the conventional radioimmunoprecipitation assay (RIPA), a recently described cell-based assay (CBA), and a new non-radioactive fluorescence immunoprecipitation assay (FIPA) which can measure both AChR and MuSK antibodies in one step. 102 MG sera were subsequently tested by CBA and FIPA in Tianjin, China. Based on the different serological subgroups, the clinical features of these 153 MG patients were analyzed.
We first confirmed the sensitivity and specificity of the assays in Oxford. There was good agreement between the FIPA and the RIPA for AChR Abs (r² = 0.6; p < 0.0001) with 80% positivity in the RIPA and 76% in the FIPA. Two patients were positive for MuSK Abs (4% of total) by both RIPA and FIPA assays. CBA was more sensitive for MuSK Abs, identifying an additional 3 patients. In Tianjin, using the FIPA and CBA, 84/102 (82%) AChR Ab positive patients and four MuSK Ab positive patients were identified. In the whole group of 153 MG patients, there were no differences in clinical features between different antibody subgroups. However, there were 30 patients with thymomas (20%), of whom one had MuSK antibodies. Moreover, two patients with purely ocular MG also had MuSK antibodies.
Both the FIPA and CBA were established in China and should prove useful for diagnostic testing. Including the CBA for MuSK antibodies increased the number of MuSK-MG patients to 6% of the total, and 33% of the patients without AChR antibodies. The clinical features were mainly relatively mild but thymic tumors were common.
建立检测乙酰胆碱受体（AChR）和肌肉特异性激酶（MuSK）抗体的非放射性检测方法。证明这些检测方法可在中国天津用于检测重症肌无力（MG）患者。
在英国牛津，使用传统的放射免疫沉淀检测法（RIPA）、最近描述的细胞基础检测法（CBA）和一种新的非放射性荧光免疫沉淀检测法（FIPA）对 51 例中国 MG 患者血清中的 AChR 和 MuSK 抗体进行检测。随后，在中国天津用 CBA 和 FIPA 对 102 例 MG 血清进行了检测。基于不同的血清学亚组，分析了这 153 例 MG 患者的临床特征。
我们首先在牛津证实了这些检测方法的敏感性和特异性。FIPA 与 RIPA 检测 AChR Ab 的结果具有良好的一致性（r²=0.6；p<0.0001），RIPA 的阳性率为 80%，FIPA 的阳性率为 76%。有两名患者同时通过 RIPA 和 FIPA 检测出 MuSK Ab（占总数的 4%）。CBA 对 MuSK Ab 更为敏感，又发现了 3 例。在天津，使用 FIPA 和 CBA，在 102 例 AChR Ab 阳性患者中，有 84 例（82%）和 4 例 MuSK Ab 阳性患者被识别。在 153 例 MG 患者中，不同抗体亚组之间的临床特征没有差异。然而，在 30 例胸腺瘤（20%）患者中，有 1 例存在 MuSK 抗体。此外，两名单纯眼肌型 MG 患者也存在 MuSK 抗体。
FIPA 和 CBA 在中国均已建立，应该对诊断检测有用。纳入 CBA 检测 MuSK 抗体，使 MuSK-MG 患者总数增加到 6%，无 AChR 抗体的患者增加到 33%。这些患者的临床特征主要较为轻微，但胸腺肿瘤较为常见。
