Low-dose IL-2 reduces lymphocyte apoptosis and increases naive CD4 cells in HIV-1 patients treated with HAART.

During HIV disease an increased in vitro apoptosis of peripheral blood mononuclear cells has been demonstrated. This can be reversed in vitro by interleukin (IL)-2. Recent trials with highly active antiretroviral therapy (HAART) and IL-2 in HIV-1-infected patients showed promising immunological and clinical results. Here we investigated the effects of subcutaneous low-dose IL-2 administration in combination with HAART on in vitro apoptosis and the relationship between apoptosis, CD4(+) counts, and HIV replication. Twenty-two asymptomatic HIV patients were randomized for HAART (arm I) and HAART plus IL-2 (arm II). Spontaneous apoptosis was decreased in both arms after 28 weeks of therapy but the reduction was highly significant only in arm II (P = 0.05 vs P = 0.001). As the percentage of apoptosis decreased, there was a significantly higher increase of both CD4(+) and CD4(+) naive T cells in arm II vs arm I. HIV plasma viremia was reduced in all patients after therapy. Our data suggest that intermittent therapy with low-dose subcutaneous IL-2 in addition to HAART induces a positive immunomodulation in asymptomatic HIV-infected patients.