News (Updated
December 29, 2008)
[Home]
[Previous
news]
Mon Dec 22, 2008 7:00pm
EST
By Julie Steenhuysen
CHICAGO (Reuters) - Doctors hope to be able
to better predict which patients will respond to traditional treatment for the
hepatitis C virus using a new method for identifying slight variances in the
virus' genetic makeup.
A team at Saint Louis University in Missouri
analyzed genetic patterns of the virus in patients infected with Hepatitis C to
see if they could tell why many patients fail to respond to standard treatment
with pegylated-interferon and ribavirin.
The year-long therapy activates the body's
natural defenses against viruses, but patients often feel as though they have a
bad case of influenza. Only about half of the people who suffer through the
treatment actually respond.
"This is a very difficult therapy to
take. It's really hard on the patient," said John Tavis, a professor of
molecular and microbiology at
"If you can identify those patients who
aren't going to respond anyways because they've got a strain that is highly
resistant to the drug, then you just don't treat those patients and you save
them $20,000 to $30,000 in medical bills just from drugs alone -- not to mention
the side effects," Tavis said in a telephone interview.
He and colleagues studied the ribonucleic
acid or RNA chains of the hepatitis C virus, looking for patterns that would
explain why some people responded to the treatment while others did not.
Using a math formula, they zeroed in on a
specific pattern of changes called "covariance networks" that differed
depending on whether the drug worked. And these patterns proved to be a strong
indicator of whether the virus was especially resistant to therapy.
"What we found will allow a doctor to
predict whether or not a medication will work in a patient," Tavis said in
a statement.
The finding also may have implications for
other types of RNA viruses, such as human immunodeficiency virus or HIV or the
influenza virus.
"It's a pretty easy process. The
algorithm can be applied fairly quickly," he said. Whether or not it turns
up a pattern that will be useful is less clear, he said.
Hepatitis C is a blood-borne liver disease
that can lead to chronic liver disease, liver cancer, cirrhosis and death. The
virus affects an estimated 3.2 million people in the
Pegylated interferon brands include Roche
Holding AG's Pegasys and Schering-Plough Corp's Pegintron.
(Editing by Cynthia Osterman)