The HMGB1 is increased in CSF of patients with an Anti-NMDAR encephalitis

Background: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune disorder of the central nervous system (CNS). Interleukin (IL)-6 and IL-17A may play important roles in the pathogenesis of this disease. High-mobility group box protein 1 (HMGB1), a small but highly conserved ubiquitous protein, is recognized to be a potent innate inflammatory mediator that can activate the nuclear factor light chain enhancer of activated B cells and release cytokines such as IL-6 and IL-17A when released extracellularly. However, whether cerebrospinal fluid (CSF) HMGB1 levels are altered in anti-NMDAR encephalitis is still unclear.

Objective: The aim of this study was to determine whether a correlation exists between the CSF concentrations of HMGB1 and IL-6 and IL-17A in anti-NMDAR encephalitis patients. We also sought to assess whether HMGB1 influences the clinical outcomes in anti-NMDAR encephalitis patients.

Methods: Thirty-three patients with anti-NMDAR antibodies and 38 controls were recruited. CSF HMGB1 was measured using an enzyme-linked immunosorbent assay. The main clinical outcomes were evaluated using the modified Rankin scale (mRS). The data were extracted using microarray analysis software.

Results and conclusion: Our results showed significant increases in CSF HMGB1, IL-6, and IL-17A (P < .05) in anti-NMDAR encephalitis patients. But between 3 months' mRS scores in anti-NMDAR encephalitis patients and CSF data, there was no correlation. Our study suggests that HMGB1 CSF levels are increased in patients with anti-NMDAR encephalitis and reflect the underlying neuroinflammatory process.