Autoimmune encephalitis after Japanese encephalitis in children: A prospective study.

OBJECTIVE: To explore anti-neuronal surface antibodies and identify associated serum predictors of autoimmune encephalitis after Japanese encephalitis (JE). METHODS: This prospective study first detected anti-neuronal surface antibodies and cytokines in the serum and cerebrospinal fluid (CSF) of JE patients within one week of symptom onset. Anti-neuronal surface antibodies and cytokines in the serum were detected on day 21 post-JE. If the patients relapsed during the convalescent phase, we simultaneously detected JE virus RNA and cytokines in the CSF, as well as anti-neuronal surface antibodies in the serum and CSF. RESULTS: All 31 patients were negative for anti-neuronal surface antibodies at the onset of JE in the serum and CSF. During the convalescent phase, five patients developed autoimmune encephalitis (two had anti-N-methyl-d-aspartate receptor [NMDAR] antibodies, one had γ-aminobutyric acid-B receptor [GABABR] antibodies, and two had other antibodies against unknown neuronal surface antigens). Patients who developed autoimmune encephalitis experienced more severe outcomes than those who did not at the one-year follow-up (p = 0.044). The levels of serum CXCL13 and IL-6, as well as CXCL13, BAFF, CXCL10, and MMP-9 in the CSF were increased in the convalescent phase compared to the acute phase in patients who developed autoimmune encephalitis (p < 0.05). CONCLUSION: In addition to anti-NMDAR antibodies, anti-GABABR antibodies and antibodies against unknown neuronal surface antigens can trigger autoimmune encephalitis following JE. Patients who developed autoimmune encephalitis had a poorer prognosis at the one-year follow-up. Serum CXCL13 may represent a predictor of autoimmune encephalitis after JE.