The main cause of death for people with HIV/AIDS is not the disease itself, but rather other illnesses that take over when the body's defenses are low. About one-third of people with HIV are also infected with the liver disease Hepatitis C. As more of these patients receive HIV treatment, Hepatitis C is emerging as a leading cause of death. Until recently, doctors have had little success treating Hepatitis C in HIV patients. A new treament may change this.

Two recent studies in the New England Journal of Medicine show a new combination of Hepatitis C medicines can cure the liver disease, even in patients also infected with HIV.

People who have both HIV and Hepatitis C are said to be "coinfected" with both deadly viruses. Normally, doctors treat Hepatitis C by stimulating the body's immune system with a naturally occurring protein called interferon. They use interferon in combination with another drug, ribavarin. But because HIV patients have weak immune systems, they have not responded well to this traditional combination.

A new form of interferon, called peg-interferon, works better in regular Hepatitis C patients. The two new studies show peg-interferon works better for HIV coinfected patients, as well. In the first study, researchers tested the peg-interferon-ribavarin combination in almost 900 coinfected patients from 19 countries. They found that, compared to the traditional medicine, the peg-interferon treatment cured two out of five Hepatitis C cases. This is about twice the previous rate.

Physician Francesca Torriani from the University of California in San Diego wrote the paper, and says this finding is a breakthrough. "These are results that we have never seen in any coinfection trial. These are the best results ever. And they are really definitive, because the trial was so large," she says. "We can help eradicate Hepatitis C infection in a significant proportion of patients who are both infected with the HIV virus and the Hepatitis C virus. These patients can go back to living their lives without Hepatitis C."

A second study on peg-interferon from the National Institutes of Health appears in the same issue of the New England Journal of Medicine. HIV expert Joseph Kovacs works at the NIH, but was not involved with this study. He says, although the NIH study has slightly different numbers, it supports the results in Dr. Torriani's paper.

The drug company Roche makes peg-interferon, and funded Dr. Torriani's study. It also provided the medicine for the NIH study. Dr. Kovacs says he doesn't believe the Roche connection had any influence on the research in the two papers. "Most drug-related studies are drug company sponsored studies, but the investigators have the independence to run the study the way they feel it should be run and analyze it the way that they feel it should be analyzed," he says.

While peg-interferon cures more coinfected patients than before, it still fails to cure most of them. Dr. Kovacs says part of the reason is that some strains of Hepatitis C are harder to kill than others, and that patients coinfected with HIV are weaker than normal. Dr. Kovacs adds the NIH study also suggests peg-interferon may help coinfected patients, even if it does not cure them.