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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.