Relation between Epstein-Barr virus and multiple sclerosis: analytic study of scientific production.

Numerous studies have been carried out to determine whether infection by the Epstein-Barr virus (EBV) can be considered as a risk factor for multiple sclerosis (MS). This work is a meta-analysis of case-control observational studies published before January 2009 aimed at assessing the degree of association between EBV and MS infections. A Medline electronic database search was carried out using "Epstein-Barr virus" and "multiple sclerosis" as keywords, from which we selected 30 published studies that met our methodology criteria. We found an association between MS and an exposure to EBV, studied by determining the anti-VCA IgG antibodies (odds ratio [OR] = 5.5; 95% confidence interval [CI] = 3.37-8.81; p < 0.0001), anti-complex EBNA IgG (OR = 5.4; 95% CI = 2.94-9.76; p < 0.0001) and anti-EBNA-1 IgG (OR = 12.1; 95% CI = 3.13-46.89; p < 0.0001). No significant association could be found when studying anti-EA IgG (OR = 1.3; 95% CI = 0.68-2.35; p = 0.457), EBV DNA in serum (OR = 1.8; 95% CI = 0.99-3.36; p = 0.051) and DNA in brain tissues and in cerebrospinal fluid (CSF) (OR = 0.9; 95% CI = 0.38-2.01; p = 0.768). This meta-analysis detected an association between infection by EBV and MS through the investigation of antibodies, mainly anti-EBNA-1, anti-complex EBNA and anti-VCA IgG.