BY BENJAMIN RYAN
PREVENTION
TREATMENT
CURE
CONCERNS
Preventing HIV transmission by giving antiretrovirals to people at high risk of contracting the virus, known as pre-exposure prophylaxis, or PrEP, may be cost-effective in some settings. Researchers analyzed 13 different studies that evaluated PrEP’s impact in various populations, including heterosexual couples, men who have sex with men and injection drug users. The studies were conducted in regions such as southern Africa and countries that included Ukraine, the United States and Peru. The investigators found that giving PrEP to higher risk groups appeared to be the most cost-effective prevention strategy. They also found that behavior change—such as reducing the number of sexual partners—as well as adherence to PrEP were key determinants of its effectiveness.
Tiny particles, or nanoparticles, embedded with a toxin called melittin that’s found in bee venom can destroy HIV while leaving surrounding cells unharmed, according to a proof-ofconcept study conducted by scientists from Washington University School of Medicine in St. Louis. The researchers added “protective bumpers” to the surface of the melittin-embedded nanoparticles. The bumpers prevented normal cells, which are typically much larger than HIV, from coming into contact with the toxin-coated surface. HIV, on the other hand, can fit in between these bumpers, causing the melittin to kill the virus. This line of attack is different from that of antiretrovirals (ARVs), which impede different phases of the virus’s life cycle inside a cell instead of killing it entirely. Such a new approach could keep HIV from infecting a cell in the first place. Researchers hope the bee toxin may become a component of a vaginal microbicide or a salvage therapy for people who have failed numerous ARV regimens.
Scientists at Merck Research Laboratories are looking into a potential way to bring resting HIV out of latency—a necessary step in ultimately eradicating the virus from the body. A Merck-sponsored team hopes to hone strategies that may lead to a functional cure, allowing people with HIV to stop ARVs without experiencing a viral rebound. Merck scientists are investigating small molecules that may be able to enhance the amount of viral expression seen in recent studies of histone deacetylase (HDAC) inhibitors. These are drugs used for both psychiatric and neurologic purposes as mood stabilizers and anti-epileptics. More recently, the drugs have been studied as anti-cancer agents and have also shown promise as a potential component of such an HIV cure strategy, but which on their own seem insufficient to chip away at the viral reservoir.
Sexual transmission of hep C among heterosexuals is rare (it’s mostly transmitted through needle sharing), but repeated studies have shown that men who have sex with men are at risk of infection through sex. HIV-positive men, in particular those with lower CD4 counts and those who engage in unprotected receptive anal intercourse, are at significantly higher risk. Research from the University of California at Los Angeles suggests that such transmission of hep C dates as far back as the early 1980s. Another study of patients at Fenway Health in Boston found that 1.6 percent of its study population of more than 1,100 HIV-positive gay men became infected with hep C each year, which researchers attributed mostly to sexual transmission and non-injection drug use. (Shared cocaine straws may transmit the virus between nasal passages.) The Fenway study authors recommend that HIV-positive gay men test routinely for hep C and that health care providers give risk-reduction counseling to those who use recreational drugs or engage in unprotected sex.
PrEP May Be Cost-Effective
Can Bees Sting Away HIV?
22 POZ JULY/AUGUST 2013 poz.com
HDAC Inhibitors May Fight HIV Reservoir
Hep C Transmission Among Gay Men
ALL IMAGES ISTOCKPHOTO.COM: (PENNIES) GARRY HAMPTON, (BEES) TEMMUZ CAN ARSIRAY; (TEST TUBES) YANGNA; (HOLDING HANDS) KLAPTOMAN
RESEARCH NOTES