New clue may help predict course of hepatitis infection

Researchers studying hepatitis C - which affects some 170 million people worldwide - have found a clue that may help them predict which patients will recover and which will develop the chronic form of the disease.

"There is something at play in earliest stages of infection where you can really see the destiny of the patients," said Dr. Patrizia Farci of the University of Caligari in Italy.

The finding, reported in Friday's issue of the journal Science, opens new avenues to improve the understanding of the body's immune response to the hepatitis infection, she said.

About 15 percent of people infected with hepatitis C recover from the disease, while the rest tend to develop a chronic infection, she explained. In many victims the disease persists for years, leading to cirrhosis and cancer of the liver.

Farci, who has been doing research at the National Institute of Health here, said her team studied the changing forms of the virus in infected patients. Many viruses, like those that cause colds and the flu, change often, making it hard to develop treatments and vaccines.

"In patients that recover (from hepatitis C), you see a dramatic decrease in genetic diversity, whereas in patients that progress to choroncity you see that there was a dramatic increase in the genetic diversity" of the virus, she said.

This became evident in the first 10 to 12 weeks after infection, she said.

Her research team theorized that the patients who are able to recover from the disease have more effective immune responses, which gradually eliminate each form of the virus until it is cleared from the system.

In other patients, the virus can evolve into many different forms, making it harder for the body to battle, and leading to a chronic infection or acute form of the disease.

The finding will help physicians better predict the outcome for patients and may lead to new research into the immune system and ways to help patients fight the disease, Farci said.

Science is published by the American Association for the Advancement of Science.