Study demonstrates how EBV sequestered in the brain causes the nerve cell damage of MS – suggests it may play a role in other disorders, and may respond to rituximab, or antiviral therapies the researchers are now preparing for trial
A new study by researchers at Queen Mary, University of London shows how the Epstein-Barr virus tricks the immune system into triggering an acute inflammatory process and nerve cell damage in the brain, which is known to cause MS.
Previous research has suggested a link between the Epstein-Barr virus (EBV) and multiple sclerosis, but until now the research has remained controversial, since scientists had failed to substantiate the link.
The new study proves the virus is involved in a manner more sophisticated and subtle than previously imagined, and may offer new ways to treat or prevent the disease.
MS is a neurological condition that affects around 100,000 people in the UK. It can cause vision problems and difficulties with walking and fatigue, and tends to strike mainly young and middle-aged women.
Its root causes are not completely understood, but both genes and environment are known to play a role. Some previous research has suggested that EBV triggers MS, but subsequent studies had failed to find the connection.
The new research, published Jan 3 by the journal Neurology, looked at post mortem brains of MS patients, examining areas where neurological damage had recently occurred. (See “Association of innate immune activation with latent Epstein-Barr virus in active MS lesions.”)
Dr. Ute-Christiane Meier from Barts and the London Medical School, part of Queen Mary, led the research. She explained:
“EBV is quite a clever virus; when it’s not growing and spreading it can hide away in our immune cells… In this study we used a different technique which allowed us to detect the virus in the brains of some people affected by MS, even when it was hiding away in the cells.”
Dr Meier and her team of collaborators found that, although the virus was not actively spreading, it was releasing a chemical message into areas of the brain nearby.
This chemical message – made up of small RNA molecules – was activating the body’s immune system, causing inflammation. This damages nerve cells in the brain and causes MS symptoms.
Dr Meier continued:
“We have to be careful and have to study more MS brains, but this is potentially very exciting research. Now we understand how EBV gets smuggled into the brain by cells of the immune system and that it is found at the crime scene, right where the attack on our nervous system occurs. Now we know this, we may have a number of new ways of treating or even preventing the disease.”
Possible Target for Rituximab or Anti-Virals
One possibility is the widely-used cancer treatment Rituximab; a drug which is known to kill the cells of the immune system in which the virus hides. It is now being trialed as a treatment for MS – as well as myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS).
Another possible approach, using anti-viral treatment, will be tested in clinical trials currently in preparation by Professor Gavin Giovannoni and colleagues, also at Queen Mary.
Dr. Meier adds:
“If we can pinpoint EBV as a trigger, it’s possible that we could alter the course of MS or potentially even prevent the condition by treating the virus. MS so often strikes young women, and its unpredictable nature makes it an incredibly difficult disease to live with. We desperately need better ways to tackle the condition.”
Interestingly, the research also hinted that infection with EBV and its action on the immune system could also be playing a role in other brain diseases such as cancer (e.g., lymphoma) and stroke.
This research was supported by the Medical Research Council and MS charities, Roan Charitable Trust and Aims2Cure.
Source: Based on Queen Mary University of London press release, Jan 4, 2012