Cerebrospinal fluid metabolites and multiple sclerosis: A two-sample Mendelian randomization study.

Area of Science:

• Neuroscience
• Metabolomics
• Genetics

Background:

• Epidemiological studies suggest associations between cerebrospinal fluid (CSF) metabolites and multiple sclerosis (MS).
• The causal relationship between CSF metabolites and MS remains unclear due to potential confounding factors and reverse causation.
• Understanding these causal links is crucial for developing effective MS prevention and treatment strategies.

Purpose of the Study:

• To investigate the causal relationship between 338 CSF metabolites and the risk of developing MS.
• To utilize Mendelian randomization analysis to establish causality, overcoming limitations of observational studies.
• To identify specific CSF metabolites that may serve as biomarkers or therapeutic targets for MS.

Main Methods:

• A 2-sample Mendelian randomization (MR) analysis was conducted using genome-wide association studies (GWAS) data.
• Summary statistics for 338 CSF metabolites were obtained from a GWAS of 689 participants.
• Summary statistics for MS were derived from a large GWAS including 115,803 participants (47,429 cases, 68,374 controls).
• Inverse-variance weighted (IVW) methods were used for primary analysis, complemented by extensive sensitivity analyses to ensure robustness against bias.

Main Results:

• The IVW analysis indicated a suggestive causal link between higher levels of beta-alanine, 1-stearoyl-2-arachidonoyl-gpc, and allantoin, and an increased risk of MS.
• Conversely, Wald ratio analysis revealed that higher levels of N,N,N-trimethyl-l-alanyl-l-proline betaine, butyrate, and N-acetylglycine were associated with a reduced risk of MS.
• Sensitivity analyses confirmed the robustness of these findings and ruled out significant biases from heterogeneity and horizontal pleiotropy.

Conclusions:

• This study provides genetic evidence supporting a causal role for specific CSF metabolites in MS development.
• Certain CSF metabolites are associated with increased MS susceptibility, while others appear protective.
• Targeting these CSF metabolites could represent a novel strategy for MS prevention or intervention.