Clinical analysis and literature review of anti⁃contactin⁃associated protein 2 antibody⁃ associated encephalitis

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.

DOI: 10.3969/j.issn.1672⁃6731.2024.05.006