The study, presented at the XVI International AIDS Conference in Toronto, involved more than 850 sex-trade workers in Kenya.
Most of the women were HIV-positive, but 130 remained HIV-negative despite having sex with more than 500 infected men over a three-year period.
Seeking to find out if any genetic links could explain their resistance to the virus, Canadian researchers homed in on a gene called human leukocyte antigen-G, or HLA-G, that helps the immune system recognize foreign invaders such as HIV.
Work Could Lead To HIV Vaccine
The study showed that sex workers who didn't harbor the virus were about twice as likely to have certain HLA-G variants, compared with sex workers who were infected.
The research team included Francis Plummer, M.D., of the University of Winnipeg in Canada.
The next step is to figure out why these variants are associated with resistance, says researcher Will Turk, an undergraduate at the University of Winnipeg.
"If we can figure out why, we might be able to design a drug to lower infection," Turk tells WebMD.
Joep Lange, M.D., Ph.D., a leading AIDS specialist from the University of Amsterdam, agrees.
Understanding which genetic variants keep the virus from taking hold in the body may also help in the development of vaccines to prevent HIV, he says.
The study was one of several dozen highlighted as being noteworthy by the conference organizers. About 4,500 studies are being presented at the meeting.
SOURCES: XVI International AIDS Conference, Toronto, Aug. 13-18, 2006. Joep Lange, M.D., PhD, professor of medicine, University of Amsterdam. Will Turk, University of Winnipeg, Manitoba, Canada.
By Charlene Laino
Reviewed by Louise Chang, M.D.
© 2006, WebMD Inc. All rights reserved