COCAINE INCREASES HIV RISK

Scientists say that they have shown that cocaine use appears to make immune cells more susceptible to HIV.

It’s often said that the spread of HIV has been fuelled by substance abuse, and not just when it comes to shared needles. It’s known that drug use also often leads to high-risk sexual behaviour.

There is, however, relatively little research into how drugs can impact the body’s defences against the virus. But a new UCLA study published in the October issue of the Journal of Leukocyte Biology examines how cocaine affects a unique population of immune cells called quiescent CD4 T cells, which are resistant to the virus that causes AIDS.

The results, say researchers, is that Cocaine makes the cells susceptible to infection with HIV, causing both significant infection and new production of the virus.

“The surprising result was that the changes cocaine induced on these cells were very minimal, yet they were sufficient to fuel infection,” said the study’s senior author, Dimitrios Vatakis, an assistant professor of medicine in the division of hematology–oncology at the David Geffen School of Medicine at UCLA.

For the year-long laboratory study, the researchers collected blood from healthy human donors and isolated quiescent CD4 T cells.

They exposed the cells to cocaine, then infected them with HIV. They harvested the samples over different time points to trace the cells’ susceptibility to infection at different stages of HIV’s life cycle, comparing the infected cells with untreated cells.

They found that a three-day exposure to cocaine made the cells more susceptible to HIV infection by stimulating two receptors in the cells, called σ1 and D4. The findings suggest that cocaine use increases the pool of T cells in the human body that can become infected by the virus.

The researchers caution that, as with all laboratory studies, the results may not necessarily be borne out in the same way in the real world. They noted, however, that they have data from animal models that support and strengthen their observations.

Researchers also said that the results suggest that there could be “significant implications” for HIV positive individuals who abuse or use stimulants such as cocaine.

The next stage in the research will be to more closely examine the means by which cocaine makes these once-resistant cells susceptible to infection and if the drug does indeed lead to a higher viral reservoir.