Department of Neurology, Tongde Hospital of Zhejiang Province, Hangzhou, China.
Department of Neurology, Second Affiliated Hospital School of Medicine Zhejiang University, Hangzhou, China.
Front Immunol. 2021 May 21;12:652820. doi: 10.3389/fimmu.2021.652820. eCollection 2021.
Anti-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) encephalitis, a rare subtype of autoimmune encephalitis, was first reported by Lai et al. The AMPAR antibodies target against extracellular epitopes of the GluA1 or GluA2 subunits of the receptor. AMPARs are expressed throughout the central nervous system, especially in the hippocampus and other limbic regions. Anti-AMPAR encephalitis was more common in middle-aged women and most patients had an acute or subacute onset. Limbic encephalitis, a classic syndrome of anti-AMPAR encephalitis, was clinically characterized by a subacute disturbance of short-term memory loss, confusion, abnormal behavior and seizure. Magnetic resonance imaging often showed T2/fluid-attenuated inversion-recovery hyperintensities in the bilateral medial temporal lobe. For suspected patients, paired serum and cerebrospinal fluid (CSF) testing with cell-based assay were recommended. CSF specimen was preferred given its higher sensitivity. Most patients with anti-AMPAR encephalitis were complicated with tumors, such as thymoma, small cell lung cancer, breast cancer, and ovarian cancer. First-line treatments included high-dose steroids, intravenous immunoglobulin and plasma exchange. Second-line treatments, including rituximab and cyclophosphamide, can be initiated in patients who were non-reactive to first-line treatment. Most patients with anti-AMPAR encephalitis showed a partial neurologic response to immunotherapy.
抗 α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体 (AMPAR) 脑炎是一种罕见的自身免疫性脑炎亚型，最初由 Lai 等人报道。AMPAR 抗体针对受体的 GluA1 或 GluA2 亚基的细胞外表位。AMPAR 广泛表达于中枢神经系统，特别是海马体和其他边缘区域。抗 AMPAR 脑炎在中年女性中更为常见，大多数患者呈急性或亚急性起病。边缘性脑炎是抗 AMPAR 脑炎的一种典型综合征，临床上表现为亚急性记忆障碍、意识混乱、异常行为和癫痫发作。磁共振成像常显示双侧内侧颞叶 T2/液体衰减反转恢复高信号。对于疑似患者，建议进行基于细胞的检测的配对血清和脑脊液 (CSF) 检测。由于其更高的灵敏度，因此推荐使用 CSF 标本。大多数抗 AMPAR 脑炎患者合并有肿瘤，如胸腺瘤、小细胞肺癌、乳腺癌和卵巢癌。一线治疗包括大剂量类固醇、静脉注射免疫球蛋白和血浆置换。二线治疗，包括利妥昔单抗和环磷酰胺，可用于对一线治疗无反应的患者。大多数抗 AMPAR 脑炎患者对免疫治疗有部分神经反应。
