According to research, the Epstein-Barr virus (EBV) and a history of glandular fever (infectious mononucleosis) have been associated with an increased risk of developing multiple sclerosis (MS) across a number of ethnic groups.
The study, titled 'Epstein-Barr virus, cytomegalovirus, and multiple sclerosis susceptibility', was published by journal, Neurology.
Researchers set out to determine whether the presence of the Epstein-Barr virus or cytomegalovirus (CMV) in the blood is associated with MS in black and Hispanic people, and to what extent measures of the hygiene hypothesis or breastfeeding could explain these findings.
EBV and CMV have been associated with MS risk in white people and the timing and frequency of both viruses vary by factors implicated in the hygiene hypothesis.
Incident cases of MS or its precursor, clinically isolated syndrome (CIS), and matched controls (blacks, 111 cases/128 controls; Hispanics, 173/187; whites, 235/256) were recruited from the membership of Kaiser Permanente Southern California.
The presence of Epstein-Barr nuclear antigen-1 (EBNA-1) was independently associated with an increased odds of MS/CIS in all three racial/ethnic groups. In contrast, the presence of CMV was associated with a lower risk of MS/CIS in Hispanics, but not in blacks or whites.
Being born in a low/middle-income country was associated with a lower risk of MS in Hispanics, but not after accounting for the presence of EBNA-1. Accounting for breastfeeding did not diminish the association between CMV and MS in Hispanics.
Researchers concluded that the consistency of EBNA-1’s presence in the blood with MS across racial/ethnic groups and between studies points to a strong biological link between EBV infection and MS risk. The association between past CMV infection and MS risk supports the broader hygiene hypothesis, but the inconsistency of this association across racial/ethnic groups implies no causal associations.