October 23, 2009
Although interleukin-2 (IL-2) in combination with antiretroviral drugs (ARVs) raises CD4+ cell counts more than ARVs alone, it is not clinically beneficial to HIV patients, according to a recently published study. Scientists had theorized that IL-2 would help regenerate CD4+ immune cells, building a patient's natural immunity while ARVs controlled HIV.
"Our results show that IL-2 has no effect on the development of AIDS or on patient survival," said Dr. Jean-Pierre Routy of the Research Institute of the McGill University Health Center. "More precisely, while the presence of IL-2 leads to a faster increase of CD4+ immune cells, these cells are less functional than the CD4+ cells that regenerate naturally in patients who do not receive IL-2."
The National Institutes of Health funded the eight-year study, which enrolled more than 5,000 patients in 25 countries. Compared with ARVs alone, hazard ratios for opportunistic disease or death from any cause with IL-2 plus ARVs were 0.91 (95 percent confidence interval [CI], 0.70 to 1.18; P=0.47) among participants with 50-299 CD4+ cell counts per cubic millimeter at baseline and 0.94 (95 percent CI, 0.75 to 1.16; P=0.55) among patients with 300 or more CD4+ cell counts at baseline.