Dynamics of provirus load and lymphocyte subsets after interleukin 2 treatment in HIV-infected patients

The association of antiretroviral agents plus interleukin 2 (IL-2) represen ts an efficient approach to the treatment of HIV+ subjects. While the effec ts of IL-2 on the immune system have been investigated, little is known con cerning its impact on HIV dynamics. Two antiretroviral drugs control HIV vi remia, but have minimal effects on the proviral load, a predictor of diseas e progression and response to therapy. The aim of this study was to define the effect of rIL-2 on HIV proviral copy numbers and its relationship to ch anges in CD4(+) and CD8(+) subsets. Twelve HIV+ patients with CD4 cell coun ts between 200 and 500 cells/mm(3) were treated with six cycles of subcutan eous rIL-2, in combination with zidovudine and didanosine. This regimen res ulted in a rapid and durable decrease in proviral load in the peripheral bl ood, in an increase in CD8(+) lymphocytes, and in the emergence of a CD4(+) CD45RA(+) T subset, These results demonstrate that the rationale for IL-2 a dministration to HIV+ patients may depend not only on its effects on the im mune system, but also on the reduction of the number of infected cells, rei nforcing the notion that IL-2 can have a favorable impact on the natural hi story of HIV infection.