Hepatitis C-Related Virus Slows Progression of HIV, Study Shows
Infection with GB virus C, a "virtually unheard-of" virus related to hepatitis C, can slow the progression of HIV, according to a study published in the March 4 issue of the New England Journal of Medicine, the Pittsburgh Post-Gazette reports. Dr. Jack Stapleton of the University of Iowa and colleagues analyzed blood samples from 271 HIV-positive men who have sex with men who participated in the Multicenter AIDS Cohort Study, in which blood samples are collected from participants every six months. The samples were taken prior to 1996, when "highly effective" antiretroviral treatment first became widely available, according to the Post-Gazette (Srikameswaran, Pittsburgh Post-Gazette, 3/4). The researchers discovered that 85% of the men were infected with both HIV and GBV-C, according to BBC News (BBC News, 3/4). Men who remained infected with both viruses five to six years after first being diagnosed were three times more likely to be alive than men who cleared the GBV-C infection (Pittsburgh Post-Gazette, 3/4). After 10 years, 75% of the men who showed both viruses present at one and five years following HIV infection were alive; 39% of the men who never had GBV-C infection were alive; and 16% of the men who cleared GBV-C were alive. GBV-C, which like HIV infects CD4+ T cells, is "harmless" and "common" in the general population, according to Reuters/Arizona Daily Star (Reuters/Arizona Daily Star, 3/4).
Despite the evidence that GBV-C has a protective value against HIV, scientists are hesitant to inject patients with the virus because of the negative effects that could result if the virus is cleared (Kaiser Daily HIV/AIDS Report, 3/4/03). The study found that HIV "seemed to attack with vigor" after GBC-V was cleared, Reuters/Arizona Daily Star reports. Stapleton said, "So not only was having a persistent infection better survival-wise than not having an infection, but the subset of men who lost their virus did the worst," adding, "It's very unusual that there would be a good virus." Stapleton and colleagues are designing a study that would treat HIV-positive individuals with blood from people infected with GBV-C, according to Reuters/Daily Star (Reuters/Arizona Daily Star, 3/4). In an accompanying NEJM editorial, Drs. Roger Pomerantz and Giuseppe Nunnari of Thomas Jefferson University, suggest that further research into the specific mechanisms of the interaction is necessary and "may point to therapeutic approaches to mimicking the clinically protective effects of GBV-C in patients with HIV infection" (BBC News, 3/4). The study was funded by the NIH's National Institute of Allergy and Infectious Diseases (NIAID release, 3/3).
Also in NEJM
Although advances in antiretroviral drug treatment have led to increased survival and other benefits for HIV-positive individuals, such benefits can be "compromised by the development of drug resistance," Drs. Francois Clavel and Allan Hance of the Institut National de la Sante et de la Recherche Medicale write in a NEJM review. According to Clavel and Hance, up to 50% of patients undergoing antiretroviral therapy in the United States are resistant to at least one of the available antiretroviral drugs. Clavel and Hance focus on the "mechanisms underlying the selection of drug-resistant HIV and on the consequences of viral resistance with respect to the evolution of HIV infection" (Clavel/Hance, NEJM, 3/4). The complete article is available online.