To strengthen the understanding of the clinical features for CASPR2 neurological autoimmunity in children. A multicenter retrospective and prospective analysis of CASPR2 autoimmunity was conducted. Twenty-six patients were enrolled, including 25 with serum positivity and 3 with cerebrospinal fluid (CSF) positivity; 5 patients were co-positive with anti-NMDAR or anti-GABABR antibodies. Eleven patients (who manifested with refractory epilepsy, psychobehavioral abnormalities or germinoma) presented with low antibody titers, relatively normal MRI/EEG/CSF examinations, and poor response to immunotherapy and were thus considered false positive (42.3%). Fifteen patients were diagnosed with autoimmune encephalitis/ encephalopathy/ cerebellitis (including 1 whose condition was secondary to Japanese encephalitis). The most common symptoms included disorders of consciousness (10/15), fever (8/15), psychological symptoms/abnormal behaviors (8/15), sleep disorders (8/15), seizures (7/15), movement disorders (5/15), autonomic symptoms (5/15). Brain MRI revealed abnormalities in 10 patients (66.7%). Electroencephalography (EEG) recordings revealed a slow wave background in 13 patients (86.7%). Five patients showed elevated WBCs in CSF, and 4 patients showed elevated protein levels in the CSF. Thirteen patients received immunotherapy (rituximab was adopted in 2 cases) and recovered well. Two patients received symptomatic treatment, and the recovery was slow and accompanied by emotional abnormalities and developmental delay. Autoimmune encephalitis is the most common clinical phenotype; it can be secondary to Japanese encephalitis. Rituximab can be used in patients who respond poorly to conventional immunotherapy. The high false-positive rate of anti-CASPR2 in refractory epilepsy and the psychobehavioral abnormalities needs to be explored further.

加强对儿童CASPR2神经自身免疫的临床特征的认识。对 CASPR2 自身免疫进行了多中心回顾性和前瞻性分析。入组 26 例患者，其中 25 例血清阳性，3 例脑脊液 (CSF) 阳性；5 名患者与抗 NMDAR 或抗 GABABR 抗体共阳性。11 名患者（表现为难治性癫痫、心理行为异常或生殖细胞瘤）抗体滴度低，MRI/EEG/CSF 检查相对正常，对免疫治疗反应差，因此被认为是假阳性 (42.3%)。15例患者诊断为自身免疫性脑炎/脑病/小脑炎（其中1例继发于日本脑炎）。最常见的症状包括意识障碍（10/15）、发烧（8/15）、心理症状/异常行为（8/15）、睡眠障碍（8/15）、癫痫发作（7/15）、运动障碍（ 5/15)，自主神经症状 (5/15)。脑部 MRI 显示 10 名患者 (66.7%) 有异常。脑电图 (EEG) 记录显示 13 名患者 (86.7%) 存在慢波背景。5 名患者脑脊液中白细胞升高，4 名患者脑脊液中蛋白水平升高。13例患者接受免疫治疗（2例采用利妥昔单抗），恢复良好。2例患者接受对症治疗后，恢复缓慢并伴有情绪异常和发育迟缓。自身免疫性脑炎是最常见的临床表型；它可能继发于日本脑炎。利妥昔单抗可用于对常规免疫疗法反应不佳的患者。抗CASPR2在难治性癫痫中的高假阳性率及其心理行为异常有待进一步探讨。