Risk of MS Lower in People Living With HIV

People living with human immunodeficiency virus (HIV) appear to have a reduced risk of multiple sclerosis (MS), according to study findings published online ahead of print in the Annals of Neurology.

“This large population-based international study revealed a significantly lower risk of MS among individuals living with HIV, and among HIV-positive antiretroviral therapy-exposed individuals, than expected based on the risk in the general population,” wrote corresponding author Elaine Kingwell, PhD, of University College London in the United Kingdom, and study coauthors.

The study included 29,163 people with HIV from two patient cohorts in Sweden and Canada. Three-quarters were men. Researchers investigated the incidence rate of MS over 242,248 person-years of follow-up and compared it with a randomly selected sample from the general population. According to the study, 26.19 incident cases of MS were expected among the population with HIV. However, only 14 incident cases of MS were observed. The standardized incidence ratio for MS in the population with HIV was 0.53.

To explore the potential effect of antiretroviral therapy exposure on MS risk, researchers also calculated the standardized incidence ratio following the first exposure. In the HIV population, antiretroviral therapy occurred during 86.1% of the follow-up period, or 208,481 person-years. Again, the standardized incidence ratio for MS after exposure to antiretroviral therapy was significantly reduced: 0.55.

“There were too few pre-antiretroviral therapy exposure person-years to obtain a precise estimate of MS risk among HIV-exposed only,” researchers wrote. “These results suggest that infection with HIV or treatment with antiretroviral therapy may confer a protective effect against the development of MS.”

The team recommended further investigation into the relationship among HIV, antiretroviral therapy, and MS.

Reference

McKay KA, Wijnands JMA, Manouchehrinia A, et al. Risk of multiple sclerosis in people living with HIV: an international cohort study. Ann Neurol. Published online December 14, 2023. doi:10.1002/ana.26840