A new study has shown that people born with a genetic variation that weakens HIV can transmit the weakened virus to others. Furthermore, the study demonstrated that those they infect will fare better even if they do not have the beneficial gene themselves.
"Some people have versions of the HLA gene that are known to force HIV to tolerate mutations that damage its ability to reproduce," the authors of the study reported. This weaker virus causes slower disease progression due to its genetic composition.
The study tracked 21 women without the beneficial form of HLA who were recently infected with the weakened strain of HIV. The researchers found the women had much lower levels of HIV in their body than those carrying a form of the virus that had not mutated in this way.
"This study shows you can have a survival advantage with a virus containing specific genetic signatures associated with lower replication," said Carolyn Williamson, an AIDS researcher at the University of Cape Town who led the study.
The researchers followed the women from one to three years and found that when HIV levels fell, crucial CD4 T immune cells rose.
"It is very likely that the virus in the people who did not have the HLA genes came from individuals who did," added Williamson.
The researchers do not know how quickly the disease will progress in the newly infected women, but they think the findings could help HIV vaccine research by leading to a better understanding of why some people with HIV survive longer than others.
The full report, "Transmission of HIV-1 CTL Escape Variants Provides HLA-Mismatched Recipients with a Survival Advantage," was published in the Public Library of Science Pathogens (2008;4(3): doi:10.1371/journal.ppat.1000033).
03/20/08
SOUTH AFRICA: Some People May Transmit Weaker AIDS Virus: Study
Source: Reuters :: Michael Kahn; Courtesy of the CDC National Center for HIV, STD, and TB Prevention