PITTSBURGH, Jan. 30 -- AIDS researchers at the University of Pittsburgh have found that viral secretion in HIV-positive men follows one of three patterns, which are in turn related to different sources of HIV in the body. This discovery, which has important implications for research on vaccines and retroviral therapies, was presented on Sunday, Jan. 30, in a poster session at the Seventh Conference on Retroviruses and Opportunistic Infections in San Francisco.
"For the first time, we see that some HIV-positive men continuously produce, or shed, the virus, and that in this case the virus originates in the blood," said Principal Investigator Phalguni Gupta, Ph.D., professor, department of infectious diseases and microbiology at the University of Pittsburgh's Graduate School of Public Health. "Other men shed intermittently, and in them the virus is produced in a genital organ, probably the prostate." Another 28 percent of the participants were found to be non-shedders, meaning that virus was not detected in the semen but could be in the blood. While they are antibody-positive, non-shedders are less likely to infect their partners.
Previous research has shown that some men have the same strain of HIV in their blood and semen, while others exhibit differing strains. "Interestingly, we now see that those with the same strains in blood and semen are continuous shedders, while those with distinct virus populations are intermittent shedders," Dr. Gupta explained.
Investigators studied 18 HIV-infected men from the Pittsburgh site of the
national Multicenter AIDS Cohort Study, known locally as the Pitt Men's
Study. Participants were asymptomatic and not receiving any potent
antiretroviral therapy, such as protease inhibitors. Paired blood and semen
samples were collected at weekly intervals for 10 weeks and tested for viral
load. HIV was detected at all 10 visits in the semen of five subjects (28
Contact: Kathryn Duda
University of Pittsburgh Medical Center