A macro study suggests that the ‘kissing disease’ virus causes multiple sclerosis



Multiple sclerosis, a progressive disease that affects 2.8 million people worldwide and for which there is no definitive cure, is likely caused by infection with the Epstein-Barr virus, according to a study led by researchers at the Harvard TH Chan School of Public Health. Their conclusions have been published this Thursday in science magazine.

“The hypothesis that the Epstein-Barr virus (EBV) causes multiple sclerosis (MS) has been investigated by our group and others for several years, but this is the first study to provide convincing evidence of causality,” said Alberto Ascherio. , professor of epidemiology and nutrition at Harvard Chan School and lead author of the study. “This is a big step because it suggests that most cases of MS could be prevented by stopping EBV infection, and that targeting the virus could lead to the discovery of a cure for multiple sclerosis.”

MS is a chronic inflammatory disease of the central nervous system that attacks the myelin sheaths that protect neurons in the brain and spinal cord. Its cause is unknown, but one of the main suspects is EBV, a herpes-like virus that can cause infectious mononucleosis – the so-called ‘kissing disease’ – and establishes a latent, lifelong infection in the host.

Establishing a causal relationship between the virus and the disease has been difficult because this virus infects approximately 95% of adults.

Establishing a causal relationship between the virus and the disease has been difficult because EBV infects approximately 95% of adults, MS is a relatively rare disease, and the onset of MS symptoms begins about ten years after infection. the VEB.

To determine the connection between EBV and MS, researchers conducted a study of more than 10 million young adults on active duty in the US Army and identified 955 who were diagnosed with MS during their tour of duty.

The team analyzed serum samples taken every two years by the military and determined the EBV status of the soldiers at the time of the first sample and the relationship between EBV infection and the onset of MS during the period of active duty .

In this cohort, the risk of MS increased 32-fold after EBV infection, but did not change after infection with other viruses. The results suggest that EBV is the main cause of MS.

Delay in the onset of symptoms

Ascherio states that the delay between EBV infection and the onset of MS may be due in part to the fact that symptoms of the disease are not detected during the early stages and in part to the evolutionary relationship between EBV and the immune system of the host, which is repeatedly stimulated each time the latent virus reactivates.

“Currently, there is no way to effectively prevent or treat EBV infection, but an EBV vaccine or the use of EBV-specific antiviral drugs could prevent or cure MS,” says Ascherio.

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