Lipid Metabolism in Patients with Anti-N-Methyl-D-Aspartate Receptor Encephalitis

Lipid metabolism has been implicated in autoimmune disorders, but its relationship with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is unclear. This study examined the association of serum lipids with anti-NMDAR encephalitis.

Serum lipid profiles and C-reactive protein (CRP) were evaluated in 68 patients with anti-NMDAR encephalitis, and 68 age- and sex-matched healthy controls (CTLs). Follow-up evaluations were conducted 3 months after admission in 32 of the 68 patients. Modified Rankin scale (mRS) scores and clinical and cerebrospinal fluid parameters were evaluated in all patients.

Compared with CTLs, patients with anti-NMDAR encephalitis had significantly lower serum high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (apoA-I) levels but significantly higher serum apoB levels and apoB/apoA-I ratios. Serum HDL and apoA-I were significantly and negatively associated with serum CRP levels, whereas serum aopB levels and apoB/apoA-I ratios were positively associated with age, CRP levels, and mRS scores. Follow-up evaluations revealed that serum total cholesterol, apoA-I, and HDL-C levels were significantly higher but mRS scores were significantly lower than those before treatment, and that the increased HDL-C levels were significantly and negatively correlated with decreased mRS scores.

Serum HDL-C and apoA-I levels are reduced in the initial phase of anti-NMDAR encephalitis and recover after treatment. Further studies about the role of serum lipid in anti-NMDAR encephalitis are needed.