BACKGROUND:Epidemiological data suggest a role for common viruses in the pathogenesis of multiple sclerosis (MS), and recent data showed a negative association of past cytomegalovirus (CMV) infection on paediatric MS risk.
OBJECTIVE:Our aim was to analyze the association of CMV infection with MS risk in an adult case-control material. A meta-analysis was performed to validate our findings.
METHODS:Epidemiological Investigation in MS (EIMS) is a case-control study with incident cases and population-based controls. Anti-CMV antibody titers were measured with ELISA, and HLA-A and DRB1 genotyping was performed with SSP-PCR, in 658 MS cases, who all fulfilled the McDonald criteria for MS, and 786 controls.
RESULTS:CMV seropositivity was associated with a decreased MS risk, OR = 0.73 (0.58-0.92 95% CI), p = 0.005, adjusted for index age, gender, smoking, sun exposure, EBNA1 IgG titer and HLA-A*02 and DRB1*15. When we removed all cases and controls younger than 18 years at index, the protective effect was still apparent.
CONCLUSIONS:CMV is negatively associated with adult-onset MS pathology, consistent with results from a study on paediatric MS cases. It remains to be shown whether this negative association is due to a true protective effect of CMV infection on MS risk.
Cytomegalovirus is found throughout all geographic locations and socioeconomic groups, and infects between 50% and 80% of adults in the USA, 60% aged 6 and older are infected and over 90% of 80 year olds. It is usually unnoticed in healthy people but can be a real problem in immunosuppressed people. This study suggests that lack of CMV infection may be associated with an increased risk of MS. It may be something to do with how your immune system is shaped just like EBV infection may increase your risk