March 16, 2000 (Atlanta) -- A common gene links the very uncommon people who are infected with HIV but seem to remain invulnerable to developing full-blown AIDS. These individuals, who remain healthy for many years after being infected with HIV, may point the way to effective vaccines and treatments, according to a study in the March 14 issue of Proceedings of the National Academy of Sciences.
The research team that conducted the study searched high and low for people who not only remained healthy and had a normal immune system after years of HIV infection, but also had extremely low levels of the virus in their blood. Years of search turned up 13 of these people. Eleven of the 13 carried a protective gene. What complicates the issue -- and points to even more important findings -- is the fact that the gene also occurs in about 10% of people who do go on to develop AIDS.
Lead investigator Mark Connors, PhD, tells WebMD that this means that additional factors are involved -- and that the search for these factors may lead to breakthroughs in AIDS research. "This is the important piece that we don't understand, and it means there has to be a second piece of this puzzle," says Connors, senior clinical investigator at the National Institute of Allergy and Infectious Disease Laboratory of Immunoregulation.
Other researchers have found a protective effect for this gene, although not nearly as strong as that seen in this current study. Mary Carrington, PhD, senior scientist at NCI-Frederick, tells WebMD that genetic studies in her laboratory show that people with this gene have significantly slower HIV disease progression.
This looks like a protective gene, says Carrington, who was not involved in the study. In a recent study performed by Carrington and colleagues, she tells WebMD they found that half of the HIV-infected people with this gene developed AIDS within 14 years compared to half of people without the gene who developed AIDS sooner -- within 10 years. As of now, researchers are unable to explain how the gene is protective in HIV positive patients.
Connors suggests that further research will point the way to effective AIDS vaccines and/or treatments. Researchers hope to figure out how the gene works and then harness that power for those who don't carry the gene. However, Connors says if they never find out what makes this gene tick, "even so, these patients have been incredibly useful in telling us ... what can be done against the virus. So now we are comparing them to progressors to understand what it is that is helping them."
- Researchers believe they can learn about developing AIDS vaccines and treatments by studying the few people who have low levels of HIV in their blood and do not go on to develop the disease.
- Eleven of 13 people studied had a common gene that seems to be a protector against developing AIDS. But scientists know 1 in 10 AIDS patients also has the gene. This makes researchers think there still is a missing piece to the puzzle.
- Scientists say more research is needed to find out just how the gene protects some people before any treatments can be developed.