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Antibody Isolation May Prevent or Slow HCV

December 12, 2007

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American and Canadian scientists unite in studying a novel approach for reducing the scope of Hepatitis C infection. Their isolation and injection of specific antibodies into liver tissue demonstrates potential in preventing or slowing the Hepatitis C virus.

Treatment could slow hep C

U of A researchers, California scientists team up against global menace

Bill Mah, The Edmonton Journal; With files from Bloomberg News
Published: Friday, December 07

EDMONTON - Researchers at the University of Alberta have teamed up with California scientists to devise a potential treatment that could, for the first time, head off hepatitis C -- especially in patients who have had liver transplants.

Hepatitis C affects about 240,000 Canadians and an estimated three per cent of the world's population. The number of people infected is increasing rapidly in Canada and around the world, according to Health Canada. The disease is spread by contact with infected blood and needles.

Treatments are costly and help just half of patients, according to the World Health Organization. The virus causes chronic infections in most patients, leading to liver damage in some and cancer in others. It's the leading cause of liver transplants in the U.S. and Canada.

Several thousand people each year across North America and Europe who don't respond to drug treatment and need liver transplants. These patients are particularly at risk, since the virus comes back in 100 per cent of the cases.

"This may give us insight into how we can move forward to develop ways to prevent re-infection in patients who have hepatitis C who are going to get a transplant," said Norman Kneteman, a professor of surgery at the U of A and the director of transplantation for Capital Health.

Kneteman is referring to a set of immune proteins that, when injected into laboratory mice bred with human cells in their livers, either protected the rodents from the infection or delayed its onset.

Researchers Mansun Law and Dennis Burton at the Scripps Research Institute in La Jolla, Calif., isolated a set of antibodies that attack a part of the virus that is less susceptible to changes in its DNA.

The U.S. scientists showed that the antibodies could fight two different mutations of the hepatitis C virus, Kneteman said.

The Americans approached Kneteman, whose lab had produced mice with human liver cells.

The hep C virus only lives in human and chimpanzee liver cells.

"So we took the antibodies that they developed ... and we put them into some of our mice with human liver cells," Kneteman said.

"We gave these mice a big dose of the antibody and then we followed that up by injecting the mice with hepatitis C virus from a patient."

Four control mice that didn't get the antibody became infected quickly.

One form of the antibody delayed the infection in three of five mice, while two never were infected.

In another group, a different antibody protected three of four mice and delayed infection in the fourth.

The antibodies open up new possibilities for preventing and treating hepatitis C.

"This is the first time that we've been able to demonstrate the ability of an antibody preparation to block hep C infection for a substantial period of time in a living animal," Kneteman said.

But he said much more work needs to be done to confirm the findings, improve the antibodies and come up with "clinical-grade" forms in partnership with biotech or pharmaceutical companies. Then the antibodies would have to undergo clinical evaluation.

Law said the antibodies might be given to people who think they've been exposed, either from drug use or accidental needle sticks, to avoid chronic infection. "It would be similar to shots for rabies that are used in exposed people."

Law said that while he has been contacted by companies interested in developing a drug from the antibodies, no deal is in place. Further tests in animals, perhaps in chimpanzees, might be needed before the antibodies are tried in people, he said.

The study's findings were released Thursday in the journal Nature Medicine.

Posted by Editors at December 12, 2007 12:14 PM

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