A study points to the kissing disease virus as a cause of multiple sclerosis

The multiple sclerosis “is probably” caused by infection with the Epstein-Barr virus, which causes mononucleosis, known as kissing disease. This is how a large study carried out over 20 years is collected and published this Thursday by the magazine ‘Science’.

The research, led by Harvard University, has followed more than 10 million military in the United States and identified 955 soldiers who were diagnosed with multiple sclerosis during their tour of duty.

The hypothesis that the Epstein-Barr virus (EBV) causes multiple sclerosis has been analyzed by various scientific groups for several years, but “this is the first study to provide convincing evidence of causality“, according to the main author of the investigation, Alberto Ascherio.

The scientist considers that this is “a big step, because it suggests that the majority” of cases of multiple sclerosis “could be prevented by stopping the infection” by the virus that causes mononucleosis, and that having the Epstein-Barr virus as a target “could lead to the discovery of a cure for multiple sclerosis“.

Macro-study with military

The multiple sclerosis, which affects 2.8 million peopleis a chronic inflammatory disease of the central nervous system. Although its cause is unknown, one of the main suspects is EBV, a herpes virus that can cause mononucleosis and establishes a lifelong latent infection in the host.

Establishing a causal relationship between the virus and the disease “has been difficult” because EBV infects approximately 95% of adults, while multiple sclerosis is relatively rare and the onset of symptoms begins about 10 years after infection, the TH Chan School of Public Health said in a statement.

To determine the connection between the virus and multiple sclerosis, the researchers analyzed serum samples taken every two years from the military. Thus, they determined the Epstein-Bar virus status of the soldiers at the time of the first sample and the relationship between the infection and the appearance of multiple sclerosis during the period of active service.

The team discovered that “MS risk increased 32-fold after EBV infection, but did not change after infection with other viruses.” Levels of a biomarker of nerve degeneration typical of multiple sclerosis only increased after infection with the Epstein-Barr virus.

These results, according to the research team, “cannot be explained by any known risk factor for multiple sclerosis and suggest that EBV is the main cause” of the illness.

Ascherio has explained that the delay between infection by the virus and the appearance of sclerosis multiple “may be due, in part, to the fact that symptoms of the disease are not detected during the early phases and, in part, to the evolutionary relationship between EBV and the host’s immune system, which is repeatedly stimulated each time the virus latent is reactivated”.

There is currently no way to effectively prevent or treat Epstein-Barr virus infection, but a vaccine against it or targeting it with specific antiviral drugs “could ultimately prevent or cure multiple sclerosis“, added the expert.