Combination treatment with protease inhibitors decreases ICE expression and apoptosis in CD4 cells from HIV-infected patients. Fifteen patients who failed nucleoside analog treatment were placed on antiviral therapy that included a protease inhibitor. Blood was analyzed before and 6 to 8 weeks after treatment. Cells were analyzed for ICE and Fas-R expression, and apoptotic cells assessed by annexin V binding. There were significant decreases in ICE expression and apoptosis following treatment (P < .01), while there was no significant change in Fas-R expression. CD4 counts increased a mean of 20 cells/mL.