This study, conducted by Davey and colleagues, was a randomized trial comparing treatment with subcutaneous (injected under the skin) interleukin-2 (IL-2) plus stable antiretroviral therapy (ARV) versus ARV therapy alone in 82 patients with baseline T-cell counts of 200-500 cells. The mean T-cell count was about 345, and the mean viral load was 3.1 log using the bDNA test. Thirty-nine patients were on the IL-2 arm, and 43 were on antiretroviral therapy alone. IL-2 recipients received 5-day courses every 8 weeks for 6 cycles at a starting dose of 7.5 MIU twice-a-day, decreased as needed for toxicity. Protease inhibitor use was between 80-90% on each arm. Results were as follows:

IL-2 plus ARV	Baseline	One Year
Mean CD4 Count (% increase):	355	739 (112% increase)
% pts., bDNA<500 copies/ml:	59%	68%
% pts., bDNA<50 copies/ml:	40%	67%

ARV alone	Baseline	One Year
Mean CD4 Count (% increase):	341	405 (18% increase)
% pts., bDNA<500 copies/ml:	44%	46%
% pts., bDNA<50 copies/ml:	31%	36%

The study investigators concluded that combination antiretroviral treatment with intermittent therapy with IL-2 led to a greater increase in CD4 cells, and a trend towards lower viral loads, than combination antiretroviral therapy alone.