Prolonged suppression of human immunodeficiency virus type 1 (HIV-1) viremia in persons with advanced disease results in enhancement of CD4 T cell reactivity to microbial antigens but not to HIV-1 antigens

CD4 T cell responses were studied for >2 years in 27 zidovudine-experienced patients with advanced human immunodeficiency virus type 1 (HIV-1) infecti on who received triple combination drug therapy with indinavir, zidovudine and lamivudine or zidovudine plus lamivudine or zidovudine alone for 24-42 weeks before switching to the three-drug therapy. Subjects initially given the three drugs had viremia suppressed to undetectable levels and increases in T cell proliferative and cytokine responses to microbial antigens throu gh 2 years of followup. Patients receiving the triple-drug therapy after ei ther indinavir or zidovudine-lamivudine treatment had similar increases in T cell responses only if they also had suppression of virus load. CD4 T cel l reactivity to HIV-1 antigens was not restored. Prolonged indinavir-zidovu dine-lamivudine treatment has significant but incomplete enhancing effects on CD4 T cell reactivity, which could be important in host control of micro bial and persistent HIV-1 infections.