Epstein-Barr virus genetic variants are associated with multiple sclerosis

Area of Science:

• Virology
• Neuroimmunology
• Genetics

Background:

• The Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus implicated in various diseases.
• The Epstein-Barr nuclear antigen 2 (EBNA2) gene is a highly variable region within the EBV genome.
• A potential link between EBV and the development of multiple sclerosis (MS) has been suggested.

Purpose of the Study:

• To investigate the association between genetic variants of the EBNA2 gene and multiple sclerosis (MS).
• To determine if specific EBNA2 alleles contribute to MS susceptibility or development.

Main Methods:

• Analysis of the EBNA2 gene in 53 MS patients and 38 healthy donors (HDs) using seminested PCR and Sanger sequencing.
• High-throughput sequencing (Illumina MiSeq) was performed on a subgroup of 17 patients and 17 HDs.
• Correlation analysis with clinical data, including gadolinium-enhanced MRI and human leukocyte antigen (HLA) typing.

Main Results:

• A significant correlation was found between MS risk and an excess of the EBNA2 1.2 allele (OR = 5.13) and underrepresentation of the 1.3B allele (OR = 0.23).
• New genetic variants were identified, particularly associated with the 1.2 allele and MS, including an amino acid variation at position 245 (OR = 9.4).
• Deep sequencing revealed higher-than-expected intraindividual variability, with rare EBNA2 variants detected in all participants; no correlation with HLA typing or clinical/MRI features was observed.

Conclusions:

• The study demonstrates a strong association between Epstein-Barr virus (EBV) genomic variants, specifically within the EBNA2 gene, and multiple sclerosis (MS).
• These findings reinforce the hypothesis that EBV plays a role in the pathogenesis of MS.