DataSheet_1_Circulating plasmablasts and follicular helper T-cell subsets are associated with antibody-positive autoimmune epilepsy.docx

Autoimmune epilepsy (AE) is an inflammatory disease of the central nervous system with symptoms that have seizures that are refractory to antiepileptic drugs. Since the diagnosis of AE tends to rely on a limited number of anti-neuronal antibody tests, a more comprehensive analysis of the immune background could achieve better diagnostic accuracy. This study aimed to compare the characteristics of anti-neuronal antibody-positive autoimmune epilepsy (AE/Ab(+)) and antibody-negative suspected autoimmune epilepsy (AE/Ab(-)) groups. A total of 23 patients who met the diagnostic criteria for autoimmune encephalitis with seizures and 11 healthy controls (HC) were enrolled. All patients were comprehensively analyzed for anti-neuronal antibodies; 13 patients were identified in the AE/Ab(+) group and 10 in the AE/Ab(-) group. Differences in clinical characteristics, including laboratory and imaging findings, were evaluated between the groups. In addition, the immunophenotype of peripheral blood mononuclear cells (PBMCs) and CSF mononuclear cells, particularly B cells and circulating Tfh (cTfh) subsets, and multiplex assays of serum and CSF were analyzed using flow cytometry. Patients with AE/Ab(+) did not show any differences in clinical parameters compared to patients with AE/Ab(-). However, the frequency of plasmablasts within PBMCs and CSF in patients with AE/Ab(+) was higher than that in patients with AE/Ab(-) and HC, and the frequency of cTfh17 cells and inducible T-cell co-stimulator (ICOS) expressing cTfh17 cells within cTfh subsets was higher than that in patients with AE/Ab(-). Furthermore, the frequency of ICOShighcTfh17 cells was positively correlated with that of the unswitched memory B cells. We also found that IL-12, IL-23, IL-6, IL-17A, and IFN-γ levels were elevated in the serum and IL-17A and IL-6 levels were elevated in the CSF of patients with AE/Ab(+). Our findings indicate that patients with AE/Ab(+) showed increased differentiation of B cells and cTfh subsets associated with antibody production. The elevated frequency of plasmablasts and ICOS expressing cTfh17 shift in PBMCs may be indicative of the presence of antibodies in patients with AE.

自身免疫性癫痫（Autoimmune epilepsy, AE）是一类中枢神经系统炎性疾病，其临床特征表现为对抗癫痫药物耐药的癫痫发作。由于当前AE的诊断往往依赖数量有限的抗神经元抗体检测，对免疫背景开展更为全面的分析或可提升诊断准确率。本研究旨在对比抗神经元抗体阳性自身免疫性癫痫（AE/Ab(+)）与抗体阴性疑似自身免疫性癫痫（AE/Ab(-)）两组患者的特征。本研究共纳入23例符合伴癫痫发作的自身免疫性脑炎诊断标准的患者，以及11例健康对照（HC）。所有患者均接受了全面的抗神经元抗体检测，其中13例被归入AE/Ab(+)组，10例归入AE/Ab(-)组。研究评估了两组间临床特征（包括实验室检查与影像学表现）的差异。此外，本研究采用流式细胞术分析了外周血单个核细胞（PBMCs）与脑脊液单个核细胞的免疫表型，尤其是B细胞与循环滤泡辅助性T细胞（cTfh）亚群，并对血清与脑脊液进行了多重检测。AE/Ab(+)组患者与AE/Ab(-)组患者的临床参数并无显著差异。然而，AE/Ab(+)组患者外周血单个核细胞及脑脊液中的浆母细胞频率均高于AE/Ab(-)组与健康对照组；且其循环滤泡辅助性T细胞亚群中cTfh17细胞及表达诱导性T细胞共刺激分子（ICOS）的cTfh17细胞频率，亦高于AE/Ab(-)组。进一步分析显示，ICOS高表达的cTfh17细胞频率与未转换记忆B细胞频率呈正相关。本研究还发现，AE/Ab(+)组患者的血清中IL-12、IL-23、IL-6、IL-17A及γ干扰素（IFN-γ）水平均升高，而脑脊液中IL-17A与IL-6水平亦升高。本研究结果表明，AE/Ab(+)组患者的B细胞与抗体生成相关的循环滤泡辅助性T细胞亚群分化程度更高。外周血单个核细胞中浆母细胞频率升高及表达ICOS的cTfh17细胞偏移，或可作为AE患者体内存在抗体的潜在标志物。