TOPLINE:

Laboratory-confirmed Epstein-Barr virus-positive infectious mononucleosis (EBV-mono) was linked to a more than threefold higher risk for multiple sclerosis (MS) than not having EBV-mono, a new retrospective study showed.

METHODOLOGY:

• In a retrospective cohort study, researchers used data from the Rochester Epidemiology Project for more than 4700 individuals with both a laboratory-confirmed EBV infection and a diagnosis of mono between 1998 and 2022.
• The cohort was matched by age and sex with more than 14,000 individuals who did not have a positive EBV test or mono diagnosis (control group).
• The primary outcome was incidence of MS.
• The participants were followed until the earliest of the date of the last medical contact, development of MS, death, or September 30, 2023. Median follow-up times for the EBV-mono and control groups were 6 and 8 years, respectively.

TAKEAWAY:

• After adjusting for such factors as race/ethnicity, BMI, and comorbidities, the EBV-mono group had a more than threefold higher risk for MS than the control group (adjusted hazard ratio [aHR], 3.1; 95% CI, 1.2-8.3).
• During follow-up, MS development occurred in 0.17% of the EBV-mono group and in 0.07% of the control group, with incidence rates per 10,000 person-years of 2.25 vs 0.77, respectively.
• The median time to MS diagnosis was 9.7 years for individuals with EBV-mono vs 14.2 years for control individuals.
• The risk for death did not differ significantly between the two groups (incidence rate per 10,000 person years, 8.73 and 7.72, respectively).

IN PRACTICE:

“Mononucleosis is a relatively uncommon illness, but developing strategies to prevent infection with the virus that causes this disease could help us to lower the number of MS cases in the future,” lead study investigator Jennifer L. St. Sauver, PhD, Mayo Clinic, Rochester, Minnesota, said in a press release.

SOURCE:

The study was published online on April 1 in Neurology Open Access.

LIMITATIONS:

The results may have underestimated the lifetime risk for MS associated with EBV-mono because additional cases may have developed later in life. Changes in laboratory testing and diagnostic coding meant that EBV test results and diagnoses of mono were unavailable before 1998, so some EBV-mono cases in the control group may have been missed. Additionally, the exclusion of individuals with a positive EBV test but no diagnosis of mono may have produced a slightly healthier control group.

DISCLOSURES:

The study was funded by ModernaTX, Inc. Disclosure information for the study investigators is available in the original study publication.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.