Short-term effects of cannabinoids on immune phenotype and function in HIV-1-infected patients.

Cannabinoids, including smoked marijuana and Δ 9 -tetrahydrocannabinol (THC) (dronabinol, Marinol), have been used to treat human immunodeficiency virus-1 (HIV)-associated anorexia and weight loss. Concerns have been raised, however, that these compounds might have adverse effects on the immune stem of subjects with HIV infection. To determine whether such effects occur, the authors designed a randomized, prospective, controlled trial comparing the use of marijuana cigarettes (3.95% THC), dronabinol (2.5 mg), and oral placebo in HIV-infected adults taking protease inhibitor-containing highly active antiretroviral therapy (HAART). Assays of immune phenotype (including flow cytometric quantitation of T cell subpopulations, B cells, and natural killer [NK] cells) and immune function (including assays for induced cytokine production, NK cell function, and lymphoproliferotion) were performed at baseline and weekly thereafter. On the basis of these measurements and during this short 21-day study period, few statistically significant effects were noted on immune system phenotypes or functions in this patient population.