Cytomegalovirus seropositivity is negatively associated with multiple sclerosis.

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 pediatric 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 pediatric MS cases. It remains to be shown whether this
negative association is due to a true protective effect of CMV infection
on MS risk.