Data_Sheet_2_Clinical Characteristics and Short-Term Prognosis of Autoimmune Encephalitis: A Single-Center Cohort Study in Changsha, China.docx

Background and Purpose: The incidence and prevalence of autoimmune encephalitis is gradually increasing. This retrospective observational study primarily aimed to analyze the clinical characteristics of autoimmune encephalitis patients in the Second Xiangya Hospital and report patient prognoses after immunotherapy.
Methods: The clinical data of 86 patients who were diagnosed with autoimmune encephalitis from October 2014 to September 2018 were collected, and their corresponding clinical characteristics, laboratory examination, treatment, and outcome data analyzed.
Results: In our study, 72 patients (83.7%) were positive for anti-NMDAR (N-methyl-D-aspartate receptor) antibody; 5 patients (6%) for anti-GABABR (γ-aminobutyric acid receptor-A); 4 patients (4.7%) for anti-LGI1 (leucine-rich, glioma inactivated 1); 3 patients (3.5%) for anti-Caspr2 (contactin-associated protein-like 2) (1 patient was positive for both anti-LGI1 and anti-Caspr2 antibodies); and 3 patients (3.5%) for onconeural antibodies. Among the 86 patients diagnosed as having autoimmune encephalitis, 50% showed acute disease onset (≤2 weeks). The most common inducing factor was fever or cold (17/86, 19.8%). The main clinical symptoms included, among others, psychiatric disturbances (82.5%), epilepsy (60.5%), autonomic dysfunction (58.1%), sleep disorders (45.3%), consciousness disorders (45.3%), and speech disorders (46.5%). No significant correlation between ICU admission rates and CSF or serum antibody scores was observed. However, CSF antibody scores of (+ + +) and (++) were associated with longer lengths of hospitalization (p < 0.05) and a higher CSF WBC count when compared with CSF antibody scores of (+) in patients with anti-NMDAR encephalitis (p < 0.05). Additionally, there was no significant correlation between mRS score difference on admission and discharge (after immunotherapy) and age, sex, and choice of immune treatment, while immune therapy taken within 15 days from onset was more inclined to be associated with an mRS score difference ≥2 after immunotherapy in patients with anti-NMDAR encephalitis (p = 0.006).
Conclusions: Autoimmune encephalitis has an acute or sub-acute onset and presents with psychotic symptoms, epilepsy, and autonomic dysfunction. The sex ratio in anti-NMDAR encephalitis was nearly balanced. Infection was a major factor inducing anti-NMDAR encephalitis, and the CSF antibody scores could be helpful in determining its prognosis since these scores showed associations with hospitalization duration and CSF WBC counts.

研究背景与目的：自身免疫性脑炎（autoimmune encephalitis）的发病率与患病率逐年升高。本项回顾性观察研究旨在分析中南大学湘雅二医院自身免疫性脑炎患者的临床特征，并报告免疫治疗后的患者预后情况。
研究方法：收集2014年10月至2018年9月期间确诊的86例自身免疫性脑炎患者的临床资料，对其临床特征、实验室检查结果、治疗方案及转归数据进行分析。
研究结果：本研究中，72例（83.7%）患者抗N-甲基-D-天冬氨酸受体（anti-NMDAR）抗体呈阳性；5例（6%）抗γ-氨基丁酸B型受体（anti-GABABR）抗体阳性；4例（4.7%）抗富亮氨酸胶质瘤失活1蛋白（anti-LGI1）抗体阳性；3例（3.5%）抗接触蛋白相关蛋白样2（anti-Caspr2）抗体阳性（其中1例同时抗LGI1与Caspr2抗体均为阳性）；另有3例（3.5%）肿瘤相关神经抗体（onconeural antibodies）阳性。在86例确诊自身免疫性脑炎的患者中，50%呈急性起病（病程≤2周）。最常见的诱发因素为发热或感冒（17/86，19.8%）。主要临床症状包括精神行为异常（82.5%）、癫痫发作（60.5%）、自主神经功能障碍（58.1%）、睡眠障碍（45.3%）、意识障碍（45.3%）及言语障碍（46.5%）。未观察到重症监护病房（Intensive Care Unit, ICU）入住率与脑脊液（cerebrospinal fluid, CSF）或血清抗体滴度存在显著相关性。然而在抗NMDAR脑炎患者中，脑脊液抗体滴度为(+++)和(++)的患者，相较于抗体滴度为(+)的患者，住院时长更长（p<0.05），且脑脊液白细胞计数更高（p<0.05）。此外，入院时与免疫治疗后的改良Rankin量表（modified Rankin Scale, mRS）评分差值与患者年龄、性别及免疫治疗方案选择均无显著相关性，但在抗NMDAR脑炎患者中，起病15天内接受免疫治疗者，其治疗后mRS评分差值≥2的比例更高（p=0.006）。
研究结论：自身免疫性脑炎多呈急性或亚急性起病，临床表现以精神症状、癫痫发作及自主神经功能障碍为主。抗NMDAR脑炎患者的性别比例近乎均衡。感染是诱发抗NMDAR脑炎的主要因素，脑脊液抗体滴度与住院时长及脑脊液白细胞计数存在相关性，因此可辅助评估患者预后。