Grey matter

NIDA awards researchers $11.2 million grant to study how cannabis affects HIV-infected brain tissue


Many who suffer from chronic HIV use cannabis to control their symptoms. Anecdotally, patients say it helps reduce nausea, eases anxiety, lifts depression and reduces nerve pain, tingling, numbness, weight loss, headaches, tremors, constipation and general lethargy. 

Research from 2005, published in the Journal of Pain and Symptom Management, backs that up. Out of 523 patients surveyed, 143 (or 27%) used cannabis to treat their HIV symptoms. Researchers found that among those cannabis users, the most notable improvements reported were an increased appetite and reduced pain. 

“The positive responses to symptom control recorded in this study,” the paper concludes, “suggest that it is highly probable that cannabinoid medications have a medicinal role in this condition for a number of reasons.”

However, cannabinoids have immunomodulating effects on the body. A review of public research from 2021 finds that it affects T-cells, B-cells and monocytes, and causes an increase in anti-inflammatory cytokines. Using cannabis to treat a disease that depletes one’s immune cell count could be counter-productive to treating the infection — even if it helps treat the symptoms. 

That’s why the National Institute on Drug Abuse (NIDA) recently awarded researchers from Weill Cornell University an $11.2 million grant to study the effects of cannabis use on HIV-infected brain tissue. While anecdotal evidence suggests that cannabis helps HIV patients, there’s no data yet on how this drug directly affects their brain tissue. 

“We know that the virus may cause changes within the brain, but it’s not clear yet how the use of cannabis might interact with the infection,” says Lishomwa Ndhlovu, Weill Cornell professor of immunology. “This support from NIDA will allow us to collect the data we need to explore this relationship.”

This question is long-standing and extends beyond HIV symptom treatment. NIDA reports that somewhere between 25% to 40% of cancer patients also use cannabis to treat the symptoms of either the disease itself or chemotherapy treatment. And like HIV, both cancer and chemotherapy can suppress and weaken a patient’s immune system.

Raising even more concerns, other NIDA-funded research published in theInternational Journal of Molecular Sciences in 2022 suggests that under certain circumstances, cannabis use can actually stimulate cancer growth. 

Of course, there is also research to support cannabis as a useful, natural, non-addictive medication to help cancer patients ease many of the same symptoms HIV patients use it for. But while much research focuses on the relationship between cannabis use and cancer — both supporting and decrying the idea — when it comes to the relationship between cannabis use and HIV, there is very little beyond the anecdotal. That’s a problem that Ndhlovu and his team of researchers at Weill Cornell aim to resolve. 

“The goal here is to use really advanced single-cell technologies that are now made available to us to really get into the impact at the single-cell level,” Ndhlovu says. “[That will] give us a much better mapping of what may be going on.”

NIDA’s grant toward Ndhlovu’s research is an extension of its Single Cell Opioid Responses in the Context of HIV (SCORCH) program. Initially, the program was focused solely on how opioids may modify the impact of HIV on the brain at a cellular level, but it has since branched out to include all “addictive substances,” lumping cannabis into that group (Weed Between the Lines, “Shifting perspectives,” June 22, 2023). 

Ndhlovu notes that this isn’t a clinical trial. In other words, they aren’t dealing with individuals living with HIV. They’ll be using autopsy specimens and high-tech single-cell technologies to gather data on how cannabinoids affect HIV-infected human brain tissue. The results will eventually be aggregated and made available for other researchers to expand upon. 

“Because such a huge amount of data will be generated,” Ndhlovu says, “it may not be possible for one individual to analyze all of that.”

It will likely take years, Ndhlovu says. And he doesn’t expect to walk away with an end-all answer as to whether HIV patients should use cannabis to treat their symptoms or not. But if all goes to plan, they’ll end up providing a massive bank of data that could move us closer to understanding that. 


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