Interleukin-2 accelerates CD4 cell reconstitution in HIV-infected patients with severe immunosuppression despite highly active antiretroviral therapy: the ILSTIM study - ANRS 082

Background: Despite effective highly active antiretroviral therapy (HAART), some patients infected with HIV have persistently low CD4 cell counts with risk of HIV disease progression. The addition of interleukin-2, a cytokine that stimulates CD4 T lymphocyte helper cells, may benefit patients with discordant responses. Methods: A total of 72 HIV-infected patients with CD4 cell counts of 25200 x 10(6) cells/l (median 145) and plasma HIV RNA < 1000 copies/ml were randomized in a multicentre study to receive open-label 4.5 x 10(6) IU interleukin-2 subcutaneously twice daily for 5 days every 6 weeks plus their ongoing HAART or were maintained on HAART alone (control group). After 24 weeks, all patients received interleukin-2 therapy plus HAART up to week 80. Primary end-point was the CD4 T cell area under the curve minus baseline up to week 24. Results: After four cycles of interleukin-2, in an intent-to-treat analysis, the respective median CD4 cell area under the curve minus baseline values were +51 and +11 cells in the interleukin-2 (n = 34) and the control group (n = 36) (P < 0.0001). The percentage of patients in the two groups with CD4 cell counts > 200 x 10(6) cells/l was 81% and 33%, respectively (P < 0.0001). At week 80, the median CD4 cell counts in the two groups were 380 and 270 x 10(6) cells/l, respectively. Interleukin-2 treatment was reasonably well tolerated and did not result in sustained increases in plasma HIV RNA levels. Conclusions: Administration of interleukin-2 produces significant and sustained increase in CD4 cell counts in HAART-treated patients with persistent CD4 cell counts < 200 x 10(6) cells/l. (C) 2002 Lippincott Williams Wilkins.