People with HIV who use marijuana products for nausea, pain or appetite problems associated with HIV and HIV meds may have been alarmed to hear this morning's news from researchers at Harvard Medical School that the drug may encourage Kaposi's sarcoma (KS). The findings are so preliminary, however, that no one's suggesting new warnings about medical marijuana yet.

You may remember KS, the skin cancer that was a prime AIDS-defining illness in the 1980s—and whose hallmark purple lesions were an unforgettable visual marker of HIV's deadly first decade. Antiretroviral drugs have virtually knocked it out, but the Kaposi's sarcoma herpes virus (KSHV) can still cause the disease among people with extremely compromised immune systems.

The Harvard study, published in the August 1st issue of Cancer Research and funded by the National Institutes of Health, determined that low doses of THC, the active ingredient in marijuana and the prescription medication Marinol (dronabinol), stimulates proteins on endothelial cells in the body's skin and other tissues. This, the test tube study suggests, allows KSHV to enter the cells and begin reproducing.  

Connecting the study findings to real-world use of pot or Marinol is a leap the scientists have not yet made, however. “We still do not know the exact molecular events that are occurring here,” according to lead study author Jerome E. Groopman, M.D., professor of medicine at Harvard Medical School. “These results are just the first part of our ongoing research.”