Cerebrospinal Fluid Metabolomics Of Autoimmune Encephalitis

Objective:To investigate the metabolic changes of cerebrospinal fluid(CSF)in patients with autoimmune encephalitis(AE)based on nuclear magnetic resonance(NMR).Methods: NMR was used to analyze 28 cases of AE,31 cases whose AE antibody was negative but can not except AE(NA group)and 30 normal controls.All CSF was collected from our hospital from December 2016 to February 2018.The data was pretreated and normalized,then using principal component analysis(PCA)and orthogonal partial least squares-discriminant analysis(OPLS-DA)to establish the disease distinguishing model,which was verified by arrangement verification.After that,the difference metabolites with VIP> 1.0 was selected for bilateral T test to investigate the significance of the difference metabolites in the two groups.Variables that satisfied both VIP > 1.0 and p < 0.05 were significant difference.Results:This research select 36 main metabolites by NMR.We screen and identification of 10 differential metabolites in the patients with AE and 19 differential metabolites in the patients with NA.The metabolism of alanine,aspartic acid and glutamate,taurine and subtaurine,and the synthesis and degradation of ketone body have a great weight in the CSF of AE group(0.1~0.7).In NA group,glycine,serine and threonine metabolism,glyceride metabolism,taurine and the metabolism of taurine,alanine,glutamic acid and aspartic acid metabolism influence weight is bigger(0.2~0.4).They have some same metabolic pathway.Conclusions: AE patients have their special metabolic network,and the main difference from NA is the synthesis and degradation of ketone body.In the AE group and NA group,most of the metabolic pathways were the same,which suggesting that NA may be associated with the onset of AE.At the same time,we can seen Acetamide and acetic acid as the candidate diagnostic markers for the diagnosis of AE,but the results need to be verified by multiple centers and large samples.