Cocaine Use Speeds HIV Disease Progression, UCLA AIDS Institute Study in Mice Suggests
Cocaine use appears to facilitate the progression of HIV in mice, according to a UCLA AIDS Institute study, the New York Times reports. The researchers, whose report on the study was published today in the online edition of the Journal of Infectious Diseases and will be published in the March print issue, injected specially bred laboratory mice with human CD4+ T cells and HIV. The mice were then injected with either cocaine or a salt-water placebo. Cocaine-exposed mice experienced a greater reduction in the number of CD4+ T cells, immune system cells that are the target of HIV. In addition, the cocaine appeared to promote HIV replication, as mice exposed to cocaine had 200 times the amount of virus in their bodies after 10 days as the mice that had received a placebo. "We're seeing that the population of cells that are not killed off are churning out incredible amounts of virus," study co-author Dr. Gayle Baldwin said.
Applicable to Humans?
Although the study looked specifically at HIV-positive mice, and a similar study on humans would be unethical, Dr. Warner Greene, director of the University of California-San Francisco's Gladstone Institute of Virology and Immunology, said that the findings had "very significant implications" for HIV-positive people (Grady, New York Times, 2/15). Baldwin said she "suspects" the overall effect would be the same in humans. However, other AIDS researchers said it was "not clear" whether the effect of cocaine on HIV would be the same in humans as in mice. The study results are "a challenge now for human biologists to tell us is this or [is this] not important," Dr. Jeffrey Laurence, senior scientist at the American Foundation for AIDS Research and director of Cornell University's Laboratory for AIDS Virus Research, said.
Drug Use Strongly Discouraged
AIDS researchers have "long suspected" that the use of drugs such as cocaine or heroin suppresses the immune system and facilitates viral progression (Bridges, Associated Press, 2/15). However, researchers are unsure of the exact mechanisms of cocaine's impact on HIV and the immune system. "There certainly are some targets we can look at," Baldwin said, adding, "Cocaine doesn't work by itself. ... [I]t has a number of byproducts, and these byproducts can act on HIV. These can include things as straightforward as cellular mediators such as cytokines, compounds which have already shown to have an effect on HIV replication." Although researchers are still unclear exactly how cocaine "wreaks havoc with HIV," they continue to counsel drug-using HIV-positive patients to stop using drugs. "Even if cocaine had no effect on HIV replication, the consequences of [drug] use in immune-compromised population[s] is very straightforward," Baldwin said, adding that the new study could mean that "the caution against this sort of recreational drug use has now been increased 200-fold" (Mundell, Reuters Health, 2/14).