Sometimes a drug initially developed to treat one disease reveals by chance that it also has properties to combat other conditions. This is what has happened with weight loss drugs such as Ozempic, Wegovy or Mounjaro, which have been highlighted by Science magazine as a breakthrough for 2023, and which were initially intended to treat type 2 diabetes. Now, a new study shows that Antiretroviral drugs used to combat HIV may reduce the risk of developing multiple sclerosis (MS).
In the last 10 years, some studies have looked at cases of patients with multiple sclerosis who started antiretroviral therapy for HIV and then found that their multiple sclerosis symptoms had completely disappeared, or that disease progression had slowed significantly.
The authors of the work then questioned whether HIV or antiretroviral drugs could influence the risk of developing this neurodegenerative pathology and the findings of their study published in Annals of Neurology have shown that this is the case. Researchers have indicated in The Conversation that it is very difficult to determine whether HIV or antiretroviral drugs could affect MS because this requires long-term follow-up of large groups of people infected with HIV, and having Detailed medical information about HIV and MS.
To carry out their study they used large population health databases and HIV and MS clinical registries. They included virtually all people in British Columbia, Canada and Sweden who were diagnosed as HIV positive since 1992 in Canada and since 2001 in Sweden. They followed people with HIV from the date their HIV infection was first detected until the end of the study period (2020 in Canada and 2018 in Sweden), and during this period they looked for new MS diagnoses using hospital data and doctors, as well as information from specialized MS clinics.
Epstein-Barr virus inhibition, a risk factor for MS
The rate of new cases of MS among people with HIV was compared to the rate of new cases in the general population within each region to determine whether there really was a different risk of MS in people with HIV. Researchers identified more than 29,000 people with HIV and followed them for an average of almost 10 years, during which only 14 HIV-positive people developed MS, which was 47% fewer cases than expected based on general population figures. .
When they looked at people who had taken antiretroviral drugs (almost all of the study participants), and only after they started antiretroviral therapy, they found 45% fewer cases of MS than expected, meaning they found a reduced risk. among HIV-positive people who had used antiretroviral therapy.
The decrease in MS risk was more significant in women, with a 72% reduction. There were also fewer men than expected who developed MS among those infected with HIV, but the difference in risk was less pronounced in men than in women.
The antiviral properties of HIV therapy could limit the activity of the Epstein-Barr virus, thus minimizing both the risk of contracting MS and of the disease progressing in patients
The results of this study alone do not allow us to determine whether the virus or antiretroviral therapy could be responsible for the reduced risk of MS, but there are biological reasons that support both theories. HIV causes a progressive loss of CD4+ T immune cells, which are also involved in MS as they initiate the cascade of events that lead to inflammation of the brain and spinal cord. Therefore, by reducing the CD4+ T cell count, HIV infection could decrease a person’s chances of developing MS.
However, the finding that the risk of MS was lower when the HIV virus is presumably suppressed by antiretroviral drugs could also offer some hope that it is the treatment and not the virus that plays a preventive role. Possible mechanisms by which antiretrovirals may be effective in reducing the risk of MS and disability include inhibition of the Epstein-Barr virus, as increasing research highlights the important role of Epstein-Barr in MS. The antiviral properties of HIV therapy could limit the activity of the Epstein-Barr virus, thus minimizing both the risk of contracting MS and of the disease progressing in patients.
The finding that HIV infection or antiretrovirals have a protective effect against MS will contribute to a better understanding of the causes of MS and how the disease deteriorates the body. Although there are treatments available for the relapsing form of MS, none can stop the persistent progression that occurs later in the disease and the findings of this study could be an incentive for further research to determine whether antiretroviral drugs could slow the progression of the disease. multiple sclerosis.
