August 11, 2017
This week, we gain new insight into the potential pathway by which HIV may lead to neurocognitive impairment; learn a little more about an experimental approach to injectable pre-exposure prophylaxis (PrEP); get a better understanding for the link between genital bacteria and HIV risk; and explore the relationship between HIV diagnosis and the intimate partner violence experienced by pregnant women.
To beat HIV, you have to follow the science!
HIV may cause neurocognitive dysfunction by targeting small structures called peroxisomes within infected cells, according to an in vitro study of brain tissue that was published in PLOS Pathogens.
Researchers compared tissue samples from 20 people living with HIV who were diagnosed with HIV-associated neurocognitive disorders (HAND) to tissue samples from 10 people living with HIV who did not have HAND. The study showed that people with HIV exhibit changes to their microRNAs that inhibit peroxisomes when compared to people who do not have HIV.
Several neurodegenerative diseases are associated with unique microRNA expressions. HIV-positive participants with HAND had higher levels of HIV-associated microRNA expressions than HIV-positive participants who did not have HAND.
Research into microRNA changes and their potential use as biomarkers for neurological problems is ongoing, study authors noted. Since brain tissue is not easily obtained, the researchers are now working on testing for peroxisomes elsewhere in the body, according to an associated press release.
Long-acting injectable cabotegravir, a potential option for PrEP, was acceptably safe and well tolerated in a small Phase 2a clinical trial, but the dosage used was not sufficient, according to results published in The Lancet.
A total of 127 HIV-negative men from 10 sites in the U.S. were randomized to receive cabotegravir (106 men) or a placebo (21 men). For the first four weeks, the drug was taken orally every day. After a week's pause, participants received the first of three injections containing either 800 mg cabotegravir or a saline solution, depending on the study arm to which they were randomized. The other two injections were given 12 weeks apart.
Injection site reactions were the most common complaint in the study drug arm. Most participants were willing to tolerate that side effect -- and, in fact, preferred the injection over the daily tablet; 107 participants finished the injection phase (87 in the cabotegravir arm and 20 in the placebo arm). However, participants' plasma drug concentrations of cabotegravir were found to be too low over time to have substantial antiviral activity. Drug concentrations that elicit such activity are presumed to be effective in preventing HIV seroconversion. Researchers are now investigating an injection of 600 mg every eight weeks.
Uncircumcised men with high levels of anaerobic bacteria in their foreskin were more likely to HIV seroconvert than those with lower levels of the same bacteria, a study published in mBio found.
A substudy of a Ugandan HIV prevention clinical trial analyzed penile swabs from 182 uncircumcised men, 46 of whom later seroconverted. Researchers focused on the levels of 10 bacteria that are known to be lower after circumcision.
While the total bacteria levels did not differ significantly between men who seroconverted and those who did not, five of the bacteria studied were much more abundant in participants who acquired HIV. The chances for seroconversion appeared to increase by 28% to 40% when the level of these bacteria was 10 times higher than normal. Greater amounts of these bacteria in the penis were also associated with higher levels of inflammatory markers, especially interleukin-8. Study authors theorize that the higher IL-8 levels may affect the immune system and thus make the person more prone to infection.
Among women with no prior intimate partner violence (IPV), women diagnosed with HIV while pregnant were more than twice as likely as women not diagnosed to experience IPV after giving birth, researchers reported in AIDS and Behavior. This substudy of a larger South African clinical trial enrolled more than 1000 pregnant women.
Research assistants administered questionnaires at study enrollment and nine months postpartum. Over a third of all participants tested positive for HIV during pregnancy, and a tenth reported IPV after giving birth.
In contrast to women with no prior history of IPV, women who had previously been physically mistreated by their partner were not significantly more likely to experience IPV postpartum if they learned during pregnancy that they were living with HIV. However, overall, women who had experienced IPV previously were much more likely than women who had not to be assaulted after giving birth.
|HIV-Associated Neurocognitive Disorders and the Gut Microbiome|
|This Week in HIV Research: Injectable PrEP Shows Promise in New Study|
|Long-Acting Injectable Antiretrovirals for PrEP: Will the Tail Wag the Drug?|
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