Distinct Intrathecal Interleukin-17/interleukin-6 Activation in Anti-N-methyl-d-aspartate Receptor Encephalitis

The aim of this study was to compare serum and cerebrospinal fluid (CSF) cytokine/chemokine levels between anti-NMDAR and anti-LGI1 encephalitis patients. Samples from fourteen anti-NMDAR encephalitis patients, ten anti-LGI1 encephalitis patients, and ten controls were analyzed for the following cytokines/chemokines: IL-1b, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-17A, IL-23, GM-CSF, IFN-gamma, TNF-alpha, and CXCL13. Compared with controls, CSF IL-17A, IL-6 and CXCL13 were elevated in anti-NMDAR encephalitis patients (post-hoc p-values 0.002, 0.011, and 0.011, respectively) but not in anti-LGI1 encephalitis patients. In the serum, only IL-2 was increased in anti-NMDAR encephalitis. Intrathecal IL-17/IL-6 activation is a characteristic of anti-NMDAR encephalitis.