A pilot study of the safety and efficacy of supplemental arginine to enhance immune function in persons with HIV/AIDS

OBJECTIVE: We collected preliminary data on the safety and efficacy of supplemental arginine to improve natural killer cell cytotoxicity in a sample of persons with human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS). METHODS: In a randomized, double-blind, placebo-controlled pilot study in an academic medical center—based infectious disease clinic, 11 clinically stable, HIV-infected adults had been treated with highly active, antiretroviral therapy and had HIV plasma RNA levels of less than 10 000 copies/mL. Participants were randomly assigned to receive 19.6 g of arginine/d (n = 6) or placebo (n = 5) for 14 d. Plasma HIV RNA levels, neuropsychologic functioning, and self-reported adverse events were analyzed for safety of treatment. Efficacy was measured by natural killer cell cytotoxicity. RESULTS: None of the participants experienced any adverse clinical, virologic, or neuropsychologic events that necessitated withdrawal from the study. The arginine-supplemented group showed a mean natural killer cell cytotoxicity increase of 18.9 lytic units, whereas the placebo group showed an increase of 0.3 lytic units. This difference was not statistically significant (P = 0.79). CONCLUSIONS: Short-term arginine supplementation is safe for persons with HIV/AIDS. Additional studies with larger samples and longer periods are warranted to determine the effects of arginine supplementation on other indices of immune function and on clinical outcomes such as intercurrent illnesses.