Lone Ranger Wrote:

It has just recently been discovered it is genes. They will be working on both
a preventative and theraputic vaccine for it. When they are finished milking
the interferon cash cow, they might have a real cure. See below.

http://www.cnn.com/2004/HEALTH/08/06/hepatitis.recovery.ap/index.html

Genes might be key to hepatitis C
Friday, August 6, 2004 Posted: 3:47 PM EDT (1947 GMT)

Source: abcnews.com

More on this can be found at
http://www.newswise.com/articles/view/506394

Certain Genes Fight Hepatitis C Better
Scientists Say Certain Genes Make It Easier for Some People to Fight
Hepatitis C

The Associated Press



WASHINGTON Aug. 5, 2004 — Scientists may have figured out why some
people infected with liver-destroying hepatitis C essentially cure
themselves: Their genes seem to unleash a faster immune attack.
The research, reported Thursday in the journal Science, may point to
new ways to prevent or treat hepatitis C, widely considered the most
serious of a family of liver viruses.

About 20 percent of people infected with hepatitis C somehow clear the
virus from their bodies without treatment. But about 3 million
Americans and 180 million people worldwide remain chronically
infected, at risk of eventually developing liver cancer or failure.
The virus claims 10,000 to 12,000 U.S. lives annually.

Doctors have long hoped that learning why some people are lucky enough
to spontaneously recover might help them create a vaccine to prevent
hepatitis C.

Now research by a team of U.S. and British scientists suggests one key
to that recovery is genes that take the brakes off the body's
front-line immune defense, so-called natural killer cells.

The work won't benefit patients any time soon.

However, "It brings us closer to understanding how the virus works,"
said Dr. Chloe Thio of Johns Hopkins University, who co-authored the
study with researchers from Britain's Southampton University and the
U.S. National Cancer Institute.

"In the long term, whether we can use this information to modulate the
body's immune system to improve therapeutics or vaccine design that is
the ultimate goal," she said.

Hepatitis C studies in chimpanzees suggested natural killer cells were
more active in animals that recovered. To find the genes involved in
that immune response, the researchers analyzed the DNA of 1,037
hepatitis C patients, 352 of whom spontaneously recovered.

Natural killer cells are continually poised to attack if a virus
strikes. Inhibitory receptors called KIRs (pronounced "keers") keep
them in check between infections, to ensure they don't attack healthy
tissue.

The scientists discovered a particular gene combination that controls
one KIR receptor, and the molecule attached to it was twice as common
in recovered patients than in the still-infected.

But how would an immune-inhibiting system fight hepatitis?

When the body senses viral infection, it has to activate the natural
killer cells by switching off inhibiting receptors, Thio explained.
This KIR combination seems weak, "so it's easier to overcome," she
said.

There's a caveat: The genetic protection was found only in patients
thought to have received an initial low dose of hepatitis C, because
they were infected by contaminated drug or tattoo needles instead of a
blood transfusion. It may be that the extra virus from tainted blood
long a common cause of hepatitis C was simply too much for those
patients' first-line defenses to handle, Thio said.

Since 1992, the U.S. blood supply has been strictly tested for
hepatitis C, so new transfusion-related cases have plummeted. Today
the disease is most commonly spread here through injecting drug use.

Other factors also play a role in spontaneous hepatitis C recovery,
Dr. Peter Parham of Stanford University said in an accompany
editorial.

But he noted that doctors already help treat a type of leukemia by
releasing natural killer cells from a different KIR receptor, so the
question now is whether a similar strategy could be developed for
hepatitis.

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