Hong Yu, Skeie Geir Olve, Zisimopoulou Paraskevi, Karagiorgou Katerina, Tzartos Socrates J, Gao Xiang, Yue Yao-Xian, Romi Fredrik, Zhang Xu, Li Hai-Feng, Gilhus Nils Erik
Department of Clinical Medicine, University of Bergen, Bergen, Norway.
Department of Neurology, Haukeland University Hospital, 5021, Bergen, Norway.
J Neurol. 2017 May;264(5):955-962. doi: 10.1007/s00415-017-8478-z. Epub 2017 Mar 31.
Myasthenia gravis (MG) is an autoimmune disorder mediated by antibodies against proteins at the neuromuscular junction. Juvenile-onset MG (JMG) has been reported to have special characteristics. It is still unclear whether there are any pathogenic and genetic differences between juvenile and adult MG. In this study, we evaluated the clinical characteristics, autoantibody status (antibodies against AChR, MuSK, LRP4, titin and RyR) and genetic susceptibility (CHRNA1, CTLA4 and AIRE) in 114 Chinese JMG patients, and compared with 207 young adult MG patients (onset age 18-40 years). JMG patients were classified into two subgroups: the very early onset group (<8 years) and puberty onset group (8-18 years). The very early onset MG patients had a higher proportion of ocular MG and thymus hyperplasia, compared with puberty onset MG and young adult MG (P < 0.05). AChR antibodies were found in majority of JMG patients and were associated with more severe disease (P < 0.05), while other antibodies were rare in JMG. Moreover, the very early onset MG had a more prominent genetic predisposition than puberty and adult MG, affecting the susceptible genes CHRNA1 and CTLA4. JMG has the same pathogenic background as adult MG, but has typical clinical features and a prominent genetic predisposition in very early onset patients (<8 years). Specific therapeutic considerations are needed.
重症肌无力（MG）是一种由针对神经肌肉接头处蛋白质的抗体介导的自身免疫性疾病。据报道，青少年型重症肌无力（JMG）具有特殊特征。青少年和成人重症肌无力之间是否存在致病和遗传差异仍不清楚。在本研究中，我们评估了114例中国JMG患者的临床特征、自身抗体状态（抗AChR、MuSK、LRP4、肌联蛋白和兰尼碱受体抗体）和遗传易感性（CHRNA1、CTLA4和AIRE），并与207例青年成人MG患者（发病年龄18 - 40岁）进行比较。JMG患者分为两个亚组：极早期发病组（<8岁）和青春期发病组（8 - 18岁）。与青春期发病MG和青年成人MG相比，极早期发病的MG患者眼肌型MG和胸腺增生的比例更高（P < 0.05）。大多数JMG患者发现有AChR抗体，且与更严重的疾病相关（P < 0.05），而其他抗体在JMG中罕见。此外，极早期发病的MG比青春期和成人MG有更突出的遗传易感性，影响易感基因CHRNA1和CTLA4。JMG与成人MG有相同的致病背景，但在极早期发病患者（<8岁）中有典型的临床特征和突出的遗传易感性。需要特殊的治疗考虑。
