Interleukin (IL)-2 therapy impacts T-cell homeostasis. Whether IL-2 expanded CD4+ T cells may persist following viral rebound has not been fully investigated.Methods:
Patients with CD4+ T cells 500/μl or more and HIV RNA less than 50 copies/ml were randomized to continue antiretroviral therapy (ART) either alone (n = 67) or combined with three IL-2 cycles (n = 81; 6 million units) twice daily for 5 days at weeks 0, 8, and 16 before stopping ART (week 24). Patients were followed up to 168 weeks.Results:
At week 24, median CD4+ T-cell counts were 1198 and 703 cells/μl in the IL-2 and control groups, respectively (P < 0.001). At week 72, 27% (IL-2 group) and 45% (control group; P = 0.03) of patients were in failure (defined as no interruption of ART at week 24, CD4 drop below 350 cells/μl or ART resumption). After week 24, a biphasic decline (before and after week 32) of CD4 was noted −106 and −7 cells/μl per month in controls and −234 and −17 in IL-2 group (all P ≤ 0.0001). At week 96, IL-2-expanded CD4+CD25+ T cells remained higher than in the control group (26 vs. 16%, P = 0.006).Conclusion:
In IL-2-treated patients, CD4+CD25+ T cells persisting despite viral replication allow a longer period of ART interruption.