Here's another reason to say no whenever someone offers you a hit of nose candy. According to a new study published in the Journal of Leukocyte Biology, researchers have found that cocaine makes CD4 T-cells more easily infected by HIV.
The researchers separated inactive, or "quiescent," CD4 T-cells from healthy adults and then put them in an environment with cocaine. Researchers then infected the cells with HIV. They compared the rate and mechanism of the HIV infection in the cocaine-affected cells to CD4 T-cells that were exposed to HIV, but not the drug.

After three days, they discovered that cocaine made it easier for T-cells to be infected with HIV.
Not surprisingly, the researchers also found that coke boosted the spread of the virus by weakening immune cells, which puts users at a higher risk of contracting HIV. It's basically like a never ending spiral of suck. And you'd have to be pretty hooked to still want to do it.