(Reuters Health) - Upregulation of certain immunologic factors could account for the continued seronegativity of African commercial sex workers at high risk of HIV infection, according to researchers.
In the October 1st issue of the Journal of Acquired Immune Deficiency Syndromes, Dr. Taha Hirbod of the Karolinska Institute, Stockholm and colleagues note that the endogenous factors that mediate resistance to HIV transmission are still not widely explored.
"High-risk sexual practices," Dr. Hirbod told Reuters Health, "seem to alter the expression of certain innate molecules but not others, and these alterations do not necessarily increase the risk of HIV acquisition."
To investigate further, the researchers examined cervical biopsy samples from 7 HIV-negative African sex workers, 6 white HIV-positive women, who had been characterized as non-transmitters, and 10 HIV-negative controls.
Compared to the low-risk controls, the women with HIV and the high-risk sex workers had a higher expression of interferon-alpha and RANTES. More than 90% of the RANTES-expressing cells were CD8+ cells.
The researchers note that it is not possible to distinguish whether the observed upregulation was due to exposure to HIV or to other STDs.
However, they conclude that pre-existing interferon-alpha and RANTES "may be of clinical importance for protection against HIV1 at mucosal exposure."
In fact, Dr. Hirbod added, "I believe our findings highlight the importance of future studies conducted on mucosal sites as these will probably correctly guide us when constructing potential microbicide or vaccine candidates."
If you don't understand one of the words in this article,
just double-click it. A window will open with a definition
from CancerWEB's On-line Medical Dictionary. If the double-click feature
doesn't work in your browser, you can enter the word below:
