Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China.
Department of Neurology, Children's Hospital of Fudan University, Shanghai, China.
Pediatr Neurol. 2019 Sep;98:74-79. doi: 10.1016/j.pediatrneurol.2019.01.016. Epub 2019 Jan 30.
Patients in China with juvenile-onset myasthenia gravis present early, with a high prevalence of purely ocular symptoms, spontaneous remission rates, and low antibody seropositivity. Antibody detection using a cell-based assay has been reported to increase the diagnostic sensitivity in adult-onset myasthenia gravis. However, this method in patients with juvenile-onset myasthenia gravis has not been investigated.
Patients with juvenile-onset myasthenia gravis who had not received prednisone or immunosuppressive therapy were recruited between June 2015 and April 2018 at the Huashan Hospital. Clinical information was collected. Serum anti-acetylcholine receptor antibodies were detected via cell-based assay with HEK293T cells expressing acetylcholine receptor subunits and rapsyn. Additionally, the IgG antibody subclass was identified.
Eighty-two patients with juvenile-onset myasthenia gravis were enrolled in the current study. Among them, 48 patients were anti-acetylcholine receptor positive (58.5%) and 34 were seronegative (41.5%), as assessed via enzyme-linked immunosorbent assay. Cell-based assay yielded 63 positive subjects (76.8%) and 19 seronegative subjects (23.2%). All the enzyme-linked immunosorbent assay-positive samples showed robust immunofluorescence in the cell-based assay, whereas 15 of 34 enzyme-linked immunosorbent assay-negative patients (44.1%) were found to have low-affinity acetylcholine receptor antibodies. Among all the cell-based assay-positive patients, 41 were positive for both adult and fetal acetylcholine receptor antibodies (50.0%), 18 were found positive for only adult acetylcholine receptor antibodies (21.9%), and four were found to possess only fetal acetylcholine receptor antibodies (4.9%). Fifteen antibody-positive samples underwent subclassification and were confirmed to be IgG1 subclass predominant (n = 15, including eight adult and fetal acetylcholine receptor antibody positive, five only adult acetylcholine receptor antibody positive, and two only fetal acetylcholine receptor antibody positive). There were no significant differences in clinical features among patients with different antibody profiles.
The cell-based assay showed increased sensitivity in acetylcholine receptor antibody detection in Chinese patients with juvenile-onset myasthenia gravis, and most cases of Chinese juvenile-onset myasthenia gravis are still acetylcholine receptor autoantibody mediated. Furthermore, the antibodies detected are predominately of the IgG1 subclass.
中国的青少年起病型重症肌无力患者发病较早，单纯眼肌症状、自发缓解率和抗体血清阳性率均较高。使用基于细胞的检测方法已被报道可提高成人起病型重症肌无力的诊断敏感性。然而，这种方法在青少年起病型重症肌无力患者中尚未得到研究。
2015 年 6 月至 2018 年 4 月，华山医院招募了未经泼尼松或免疫抑制治疗的青少年起病型重症肌无力患者。收集临床资料。使用表达乙酰胆碱受体亚单位和rapsyn 的 HEK293T 细胞通过细胞为基础的测定法检测血清抗乙酰胆碱受体抗体。此外，还鉴定了 IgG 抗体亚类。
本研究共纳入 82 例青少年起病型重症肌无力患者。其中，48 例患者（58.5%）通过酶联免疫吸附测定法检测到抗乙酰胆碱受体阳性，34 例患者（41.5%）为血清阴性。细胞为基础的测定法检测到 63 例阳性（76.8%）和 19 例阴性（23.2%）。所有酶联免疫吸附测定法阳性样本在细胞为基础的测定法中均显示出强免疫荧光，而 34 例酶联免疫吸附测定法阴性患者中有 15 例（44.1%）被发现具有低亲和力乙酰胆碱受体抗体。在所有细胞为基础的测定法阳性患者中，41 例同时具有成人和胎儿乙酰胆碱受体抗体阳性（50.0%），18 例仅具有成人乙酰胆碱受体抗体阳性（21.9%），4 例仅具有胎儿乙酰胆碱受体抗体阳性（4.9%）。15 个抗体阳性样本进行了分类，被确认为 IgG1 亚类为主（n=15，包括 8 例成人和胎儿乙酰胆碱受体抗体阳性，5 例仅成人乙酰胆碱受体抗体阳性，2 例仅胎儿乙酰胆碱受体抗体阳性）。不同抗体谱的患者在临床特征上无显著差异。
细胞为基础的测定法在检测中国青少年起病型重症肌无力患者的乙酰胆碱受体抗体方面显示出更高的敏感性，且大多数中国青少年起病型重症肌无力仍为乙酰胆碱受体自身抗体介导。此外，检测到的抗体主要为 IgG1 亚类。
Zotero 插件