Efficacy of Low-Dose Subcutaneous Interleukin-2 to Treat Advanced Human Immunodeficiency Virus Type 1 in Persons with ⩽250/μL CD4 T Cells and Undetectable Plasma Virus Load

The immunologic efficacy of low-dose recombinant interleukin-2 (rIL-2) administered sub-cutaneously (sc) once a day in combination with highly active antiretroviral therapy (HAART) was assessed in a pilot study in patients with advanced human immunodeficiency virus (HIV) disease. Twenty-five persons with ⩽250 CD4 cells/μL and plasma HIV-1 RNA levels ⩽500 copies/mL for >24 weeks were randomly assigned to receive sc rIL-2 (3 × 106 IU once a day) with their previous antiretroviral regimen (n = 13) or to continue with the same treatment (n = 12). The level of CD4 T cells was significantly higher in the IL-2 group at week 24 (105 ± 65/μL; P < .05) but not in the control group (30 ± 78/μL). Memory T cells initially contributed to the CD4 T cell increase at week 4 (P < .05). Naive T cell increases (99 ± 58/μL) in the IL-2 group became statistically significant at week 24 compared with the control group (28 ± 27/μL; P < .05). Subcutaneous rIL-2 once a day in combination with HAART was well tolerated and improved immunologic surface markers in patients with advanced HIV infection.