Infection with anal human papillomavirus (HPV), a virus that can cause anal and cervical cancers, is associated with a higher risk of new HIV infection in previously HIV-negative men who have sex with men (MSM), according to new UCSF research.
Reported online ahead of print in the journal AIDS, the findings are available now. They are scheduled for publication in an upcoming print issue.
In previous studies, other sexually transmitted infections have been associated with higher risk of HIV infection and HPV is the most common sexually transmitted infection.
"We looked at HIV-negative men who have sex with men who were at high risk for HIV infection and who had multiple risk factors. Our results showed a strong independent association for increased risk of HIV acquisition among those men who were already infected with anal HPV," said the study's lead investigator, Peter V. Chin-Hong, MD, associate professor of clinical medicine and director of the program in transplant and immunocompromised host infectious diseases at UCSF.
The 1400 study participants were part of the EXPLORE trial, a large clinical trial to test the efficacy of a behavioral intervention for HIV-negative MSM with sites in Boston, Denver, New York and San Francisco. Risk factors were calculated from those men who became HIV-infected over the course of the trial and infections were identified by blood tests.
"We think that HPV enhances susceptibility to HIV infection through two mechanisms. Anatomically, the virus causes anal lesions. These lesions bring blood vessels closer to the surface and also the lesions' skin layer is thinner and more easily shredded, which frequently causes bleeding. These disruptions of the mucosal barrier could allow easier entry for HIV," said Chin-Hong.
In addition, HPV activates the immune system. The inflammatory cells recruited to the HPV lesionsdendritic cells, macrophages and CD4 T cellsare the imm
|Contact: Jeff Sheehy|
University of California - San Francisco