Outcomes of Therapeutic Plasma Exchange Among Children With Autoimmune Encephalitis in Vietnam

Background: Autoimmune encephalitis is a group of inflammatory brain diseases causing neuropsychiatric symptoms, seizures, and memory problems. If untreated, autoimmune encephalitis can lead to serious complications and even death. Therapeutic plasma exchange may improve outcomes in severe or treatment-resistant cases. Objective: This study aimed to describe the clinical characteristics and treatment outcomes among pediatric autoimmune encephalitis with therapeutic plasma exchange-containing regimen. Method: This retrospective case series conducted on children admitted with autoimmune encephalitis underwent therapeutic plasma exchange at Children's Hospital No.2 (Vietnam), from January 2019 to June 2022. Results: Thirty-six Vietnamese children with severe autoimmune encephalitis were included. The median age was 7.4 years, with 8.5 days from disease onset to hospitalization. 19.4% had preceding flu-like symptoms. Common manifestations included impaired consciousness (100%), cognitive impairment (91.7%), seizures (86.1%), and movement disorders (86.1%). Neurological abnormalities were assessed via cerebrospinal fluid, electroencephalography (EEG), and brain magnetic resonance imaging (MRI). Most patients had anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis, receiving intravenous methylprednisolone and therapeutic plasma exchange. Probable antibody-negative autoimmune encephalitis patients received therapeutic plasma exchange alone or with intravenous methylprednisolone. Additional treatments included antibiotics, mechanical ventilation, and vasopressors. Early therapeutic plasma exchange initiation (within 28 days) was associated with improvement. Whereas 54.5% of patients required antiepileptic drugs at discharge, only 24.2% experienced seizures at ≥1-year follow-up. Conclusions: In this study, anti-NMDAR encephalitis was the most common diagnosis among admitted patients. Although therapeutic plasma exchange requires special training and equipment and is only available in some tertiary hospitals, therapeutic plasma exchange did improve neuropsychiatric symptoms at discharge. Future research should focus on elucidating the factors that contribute to successful therapeutic plasma exchange outcomes.