September 10, 2008

STDs Increase HIV Risk If Exposed

People with genital herpes, gonorrhea, syphilis and chlamydia have an increased risk of being infected if exposed to HIV, Dutch researchers warn.

Teunis B.H. Geijtenbeek and colleagues at VU University Medical Center in Amsterdam said a way in which STDs can increase acquisition of HIV-1 infection in an ex vivo human skin explant -- isolation of cells from a piece of tissue.

In the ex vivo human skin explant model, although immature immune cells known as Langerhans cells captured HIV, they did not efficiently transmit the virus to T cells -- a group of white blood cells known as lymphocytes involved with immunity -- something that is essential for the initiation of full disease.

By contrast, efficient virus transmission was observed if Langerhans cells were activated by inflammatory stimuli. As the infectious agents that cause the STDs thrush and gonorrhea triggered the same inflammatory stimuli in vaginal and skin explants, the authors suggest that in the presence of an STD-causing infectious agent, Langerhans cells might become activated, thereby increasing an individual's risk of becoming infected with HIV.

Further, these data suggest anti-inflammatory therapies might provide a way to prevent HIV transmission, the researchers said.

The findings are published in the Journal of Clinical Investigation.