Rapid effect of interleukin-2 therapy in human immunodeficiency virus-infected patients whose CD4 cell counts increase only slightly in response to combined antiretroviral treatment.

Combined antiretroviral treatment in some human immunodeficiency virus-infected persons does not lead to a rapid increase in CD4 cell counts, and these patients may remain susceptible to opportunistic infections. A group of 13 patients with CD4 cell counts <200 cells/mm3 after > or =9 months of combined antiretroviral treatment received interleukin (IL)-2 immunotherapy (4.5x106 IU twice daily for 5 days every 6 weeks). After only 3 cycles, their CD4 cell counts increased from 123 cells/mm3 (range, 104-134 cells/mm3) to 229 cells/mm3 (range, 176-244 cells/mm3). A marked increase was noted in the naive CD45RA subpopulation of CD4 T lymphocytes. Furthermore, the magnitude of the CD4 cell count response correlated with the baseline expression levels of the antiapoptotic molecule Bcl-2. This study demonstrates that IL-2 immunotherapy can accelerate the recovery of CD4 lymphocytes in persons whose CD4 cell counts fail to increase rapidly in response to combined antiretroviral treatment.