Background and purpose: We retrospectively analyzed the clinical characteristics of children with
autoimmune encephalitis (AE) in two Chinese tertiary pediatric neurology centers. We also compared
anti-NMDAR encephalitis with and without co-positive MOG antibody, as well as specific
autoantibody-positive AE and
autoantibody-negative but probable AE. Methods: A retrospective study of children (0-18 years old) with AE in Peking University First Hospital and Children's Hospital Affiliated to Capital Institute of Pediatrics was carried out from May 2012 to January 2017. Demographics, clinical features, laboratory, and imaging findings, outcome, and co-positivity with MOG antibody were analyzed. Results: A total of 103 children had AE, 89 (86.4%) had
anti-NMDAR encephalitis, 2 (1.9%) had anti-LGI1
encephalitis, 1 (0.9%) had anti-CASPR2
encephalitis, and 11 (10.7%) were diagnosed as
autoantibody-negative but probable AE. Among the 89 children with
anti-NMDAR encephalitis, 35 were males and 54 were females. The follow-up time was 1-3 years. A total of 15 cases (15/89, 16.9%) with
anti-NMDAR encephalitis had co-positive MOG antibody (serum or cerebrospinal fluid or both). These patients were more likely to experience relapse later in life (P = 0.014). We had two cases with anti-LGI1
encephalitis, that is, one with
sleep disorder onset, and the other one with seizure onset, both of whom recovered
after treatment. One case with anti-CASPR2
encephalitis was treated with an
antiepileptic drug and fully recovered. There were 11 cases diagnosed as
autoantibody-negative but probable AE who had relatively poorer outcome than those with
autoantibody-positive AE (15.2%, 14/89). However, the difference was not significant (P = 0.08). Only one 12-year-old girl with NMDAR-antibody AE had
ovarian teratoma. Conclusion: Most subjects with AE in our Chinese cohort had anti-NMDAR AE, which had relatively good prognosis. Children with anti-LGI1 or anti-CASPR2
encephalitis were rare and showed good response on
immunotherapy. Co-positive MOG antibody was relatively common in
anti-NMDAR encephalitis, which was related to high relapse rate. In our study, the prognosis of
autoantibody-negative but probable AE seemed worse than that of specific
autoantibody-positive AE.