Ethics and Subjects

All subjects consented to participate in the study, and the work received approval from the institutional ethics committee of Sir Run Run Shaw Hospital affiliated with Zhejiang University School of Medicine and was conducted in accordance with the tenets of the Declaration of Helsinki. AE patients were diagnosed according to the autoimmune encephalitis diagnostic criteria published in The Lancet Neurology [1]. The laboratory used indirect immunofluorescence assay for CSF and/or sera antibody detection as previously reported [1]. The control individuals were diagnosed without antibodies against neuronal autoantigens. All the AE patients and control individuals show herpes simplex virus type 1 (HSV-1) PCR negative. CSF samples from these subjects were further subject to identify CSF-specific oligoclonal IgG bands (OCBs). Positive OCBs (IgG) were identified in 53.8% of patients with anti-NMDAR (7/13) and 54.5% anti-GABA_bR (6/11); 4 patient with anti-LGI1 antibodies (44.4%) and 3 patients with anti-CASPR2 antibodies (37.5%) revealed positive OCBs. Clinical information for the discovery cohort, including demographic features and symptoms, is included in Table ​Table1.1. HSE patients were diagnosed by two senior neurologists, and HSV DNA PCR from CSF samples was positive in these patients. HSV-negative controls came from the emergency department. They presented with headache and fever, and encephalitis was excluded after CSF examination and magnetic resonance imaging scanning. Clinical information of HSV-positive/negative patients is included in Table ​Table22 and Supplemental Table 2 (HSV-negative patients).

Demographic features and symptoms of cohorts with antibody-positive paraneoplastic autoimmune encephalitis

Q1, first quartile; Q3, third quartile

Demographic features and symptoms of herpes simplex encephalitis patients

CSF, cerebrospinal fluid; MRI, magnetic resonance imaging; HSV, herpes simplex virus; PCR, polymerase chain reaction