It has long been suspected that there was a link between the Epstein-Barr virus (EBV), which causes mononucleosis, and multiple sclerosis: a study published in Science appears to confirm this connection, and argues that contracting the virus would increase the chances of contract multiple sclerosis by as many as 30 times (normally the risk for the general population is 1 in 750-1000 people).
Infected. A team of researchers from Harvard University analyzed the blood samples of tens of millions of US military men, finding that 955 had been diagnosed with multiple sclerosis about five years after being infected with the Epstein-Barr virus: “Who was not he was infected, he did not get sick », Alberto Ascherio, one of the authors, points out to the BBC.
The team looked for possible connections with other viruses as well, but only Epstein-Barr’s was clearly correlated with degenerative disease. “It is quite common for a virus that infects many people to cause complications in only a few,” explains Ascario, giving the example of polio, which before the development of the vaccine infected many children but caused only 1 in 400 paralysis.
Of course, not everyone who contracts EBV gets multiple sclerosis: there are numerous other risk factors at play such as being a woman, having suffered a trauma in childhood or being exposed to low levels of vitamin D.
© Shutterstock
Exchange of identity. Multiple sclerosis is characterized by an abnormal reaction of the immune defenses, which attack certain components of the central nervous system, mistaking them for foreign agents. According to a study conducted by Bill Robinson, an immunologist at Stanford University, this “identity exchange” would take place in an attempt to fight the Epstein-Barr virus: antibodies, thinking they are defending the body from EBV, attack instead myelin, the layer of fat and protein that covers neurons and allows them to receive electrical signals.
Possible solutions. Several pharmaceutical companies are working to develop a vaccine against multiple sclerosis, but it will take decades of work before an effective one is available: in the short term, scholars hope to be able to develop a “therapeutic vaccine” that does not prevent contagion. but you help the immune system fight the virus once it is contracted. Another short-term option are therapies that target EBV-infected B cells and drugs that directly target the virus.
To make sure the EBV is really the cause of multiple sclerosis will need to conduct a study that prevents people from contracting the virus, and see if sclerosis cases decrease: if so, we will be faced with definitive proof that a simple mononucleosis can, in some rare cases, lead to development of multiple sclerosis.