Cause of MS?

Ever had it before? Well you got it again.
Doctor X
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Joined: Fri Jun 04, 2004 8:09 pm
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Cause of MS?

Post by Doctor X »

Similar to Anax's Mom topic on "t3h Autisms," Multiple sclerosis, of which there are different forms, has been one of those tragic mysteries.

The etiology seemed to be that of an auto-immune disorder, but what triggered it? Naturally, a virus seemed a likely culprit. Along with that, there have been all sort of theories. I recall someone trying to argue it was venous congestion and basically performing something like an angioplasty on the great draining sinai [Stop it! – Ed.] sinuses of the brain improved the condition in a great example of placebo. The possible consequences of doing that are "Let's Jump Off of This with Just an Umbrella!"–Level catastrophic.

Well, from those Bugger'd by Colonists:
Is a virus we all have causing multiple sclerosis?

By James Gallagher
Inside Health presenter, BBC Radio 4

Nearly three million people around the world have multiple sclerosis. Scientists think they have now uncovered a mystery cause of this incurable disease. It is a virus that nearly every one of us can expect to catch. So what does it mean for treating and even preventing MS?

["Snip!" – Ed.]

What leads the immune system astray has been a long and hotly debated mystery, but studies published this year have convincingly pointed the finger at the Epstein-Barr virus.

"It is very, very strong evidence that this virus is likely to be the cause of multiple sclerosis," Prof Gavin Giovannoni, from Queen Mary University of London, told me.
Detective work

Epstein-Barr virus (EBV) is so common that nearly all of us can expect to catch it during our lives. Most of us won't even notice, but the virus is famous for "the kissing disease", which is also known as either glandular fever or mononucleosis. EBV has been on the list of suspects for MS for decades, but definitive proof has been hard to gather because the virus is so common and multiple sclerosis is so rare.


["Snip!" – Ed.]

The crucial piece of evidence has come from the US military USA!USA!USA!, which takes blood samples from soldiers every two years. These are kept in the freezers of the Department of Defense Serum Repository and have proven to be a goldmine for research.

A team at Harvard University went looking through samples from 10 million people to establish the connection between EBV and multiple sclerosis.

Their study, published in the journal Science, found 955 people who were diagnosed with multiple sclerosis and, using the regular blood samples, they were able to chart the course of the disease.

"Individuals who were not infected with the Epstein-Barr virus virtually never get multiple sclerosis," Prof Alberto Ascherio, from Harvard, told me.

"It's only after Epstein-Barr virus infection that the risk of multiple sclerosis jumps up by over 30-fold."

The team checked for other infections, such as cytomegalovirus, but only EBV had a crystal clear connection with the neurodegenerative disease.

The soldiers caught the virus. Then signs of injury to the brain - called neurofilament light polypeptide, which is essentially the rubble from damaged brain cells - started to appear in the blood. Then they were diagnosed with MS around five years after the infection.

Prof Ascherio says the study is the "first" compelling evidence that EBV is causing the disease. He said it was "quite common" for viruses to infect lots of people, but only cause severe complications in a few. For example in the world before vaccines, "virtually all children" would catch polio but one in 400 would develop paralysis.

["Snip!" – Ed.]

Prof Bill Robinson, an immunologist at Stanford University in California, was an EBV sceptic until a couple of years ago. "I was dismissive, everybody has EBV so there's no way it can really cause MS."

Now he's not only a fully convinced convert
, he thinks he can join the dots between the virus and the myelin sheath.

His study, published in the journal Nature, showed the myelin sheath suffers from mistaken identity and is attacked by a confused part of the immune system that thinks it is fighting EBV.

His team was looking at B cells, which are the part of the immune system that manufactures antibodies to seek out viruses and other threats. These antibodies stick to the invader and signal to the rest of the immune system to come and attack.

In MS patients, they found antibodies that were designed to attack part of the virus (a protein called EBNA1) could also stick to a human protein in the brain (called GlialCAM). This case of mistaken identity, at the molecular level, is known scientifically as a cross-reaction.

Prob Robinson said: "[The virus] is inducing a cross reactivity between a viral protein that also looks like a myelin sheath protein, which results in damage that causes the symptoms of MS."

["Snip!" – Ed.]

Clearly this does not happen to everybody who is infected with EBV. And other factors come into play such as being born at higher risk of MS, being female, childhood trauma and where you live (low levels of the sunshine vitamin D) can increase the risk of the disease. The clear environmental connection was a persistent mystery of MS.

Bugger'd by Colonists
Science, it works, Weak Pussy bitches!

– J.D.