On average, people with untreated HIV progress to AIDS in about 10 years. However, a small group of HIV-positive people develop very few or no symptoms of AIDS, even without the use of antiretroviral drugs. Now researchers led by a Massachusetts General Hospital team have found that about one in 300 people with HIV never display symptoms of their infection because of the way their immune system reacts to the virus. These “controllers” — as the researchers classify the one in 300—have immune systems that, because of a genetic variation, alert the body’s virus-killing T cells of HIV’s presence, thereby preventing HIV from replicating and destroying immune cells.
Mass General and other institutions recruited thousands of HIVers in North America, Europe, and Australia for the study, whose results were published in the journal Science in November. The researchers found that the controllers showed very little of the virus in their blood, and in some cases it was entirely undetectable. Still, the patients had tested positive for HIV antibodies, indicating that they had indeed contracted the virus.
Bruce Walker, MD, a professor at Harvard Medical School and Mass General’s director of AIDS research, first became involved with controllers when the Reverend Robert Massie, a young Episcopal minister, came to his office in 1994, a decade after learning he had HIV, but still showing no symptoms. He came to Walker to find out why he was still alive and well, and he thought his case might provide information that could help others. Walker at first was certain that Massie had received a false-positive HIV antibody test result.
After Walker took his own tests and confirmed that Massie was truly HIV-positive, Massie became the first subject in a study that has grown to include 3,500 volunteers. Florencia Pereyra, MD, who worked on the research team, told HIV Plus that it is still unclear how the data from the study will aid in development of drug therapies, but she said the intense examination of the immune system will help scientists understand how to manipulate cell operations. For instance, researchers might be able to determine how to artificially replicate the controllers’ natural response in others with HIV.