Abstract:

Objective: To summarize the clinical characteristics of patients with anti-contactin-associated protein 2 (CASPR2) antibody-associated encephalitis. Methods and Results: Total 13 patients diagnosed and treated for anti-CASPR2 antibody-associated encephalitis at The Third Affiliated Hospital, Sun Yat-Sen University from August 2017 to August 2022 were collected. Initial manifestations: 9 patients exhibited limbic system symptoms, 2 patients presented with peripheral nerve symptoms (both with limb pain), one patient had cerebellar ataxia, and one patient had limb weakness. Anti-CASPR2 antibody detection: all the 13 patients underwent serum anti-CASPR2 antibody testing, which was positive in all cases; 10 patients underwent cerebrospinal fluid (CSF) anti-CASPR2 antibody testing, with 5 cases testing positive; 3 patients had other concomitant positive autoimmune antibodies. Head MRI examination: among the 13 patients, 2 patients head T₂-FLAIR showed hyperintensity in the medial temporal lobes either unilaterally or bilaterally; 2 patients had cerebral microbleeds. Treatment: 2 patients were treated only with steroids, 4 patients received only intravenous immunoglobulin (IVIg), 5 patients were treated with steroids and IVIg, one patient received rituximab only, and one patient received a combination of IVIg, steroids, protein A immunoadsorption and rituximab. Follow-up: follow-up ranged from 1-5 years, with 2 patients lost to follow-up; one patient relapsed after self-discontinuation of medication and achieved a modified Rankin Scale (mRS) score of 0 after treatment; of the remaining 10 patients, one patient showed no symptom improvement, one patient had some symptoms preventing normal life, 6 patients had normal life, 2 patients died. Conclusions: Anti-CASPR2 antibody-associated encephalitis has complex clinical characteristics, and serum antibody testing is crucial for diagnosis.

Key words: Encephalitis, Autoimmune diseases, Contactins, Autoantibodies, Immunotherapy

摘要：

目的: 总结抗接触蛋白相关蛋白-2（CASPR2）抗体相关脑炎的临床特征。方法与结果: 收集2017年8月至2022年8月中山大学附属第三医院诊断与治疗的13例抗CASPR2抗体相关脑炎患者。首发表现：9例表现为边缘系统症状，2例表现为周围神经症状（均为肢体疼痛），1例为小脑性共济失调，1例肢体乏力。抗CASPR2抗体检测：13例患者均进行血清抗CASPR2抗体检测，均呈阳性；10例患者接受脑脊液抗CASPR2抗体检测，5例呈阳性；有3例患者合并其他自身抗体阳性。头部MRI检查：13例患者中2例表现为单侧或双侧颞叶内侧T₂-FLAIR成像高信号；2例存在脑微出血灶。治疗：2例仅单纯采用激素治疗，4例仅静脉注射免疫球蛋白，5例则先后接受激素+ 静脉注射免疫球蛋白治疗，1例仅接受利妥昔单抗治疗，1例先后接受静脉注射免疫球蛋白+ 激素+ 蛋白A免疫吸附+ 利妥昔单抗。随访：进行1~5年的随访，2例失访；1例患者自行停药后复发，经治疗后改良Rankin量表（mRS）评分为零；余10例患者中1例症状未见改善，1例部分症状存在不能正常生活，6例正常生活，2例死亡。结论: 抗CASPR2抗体相关脑炎临床特征复杂，血清抗体检测对于明确诊断至关重要。

关键词: 脑炎, 自身免疫疾病, 接触蛋白类, 自身抗体, 免疫疗法