Objective: To evaluate whether interleukin (IL)-2 in patients with chronic HIV infection can maintain CD4 T cell counts during 6 months of HAART interruption.
Design: Prospective, randomized, controlled, open-label phase II noninferiority trial comparing IL-2 with HAART interruption or continuous HAART.
Methods: Forty-one IL-2-experienced (three or more prior cycles) HIV-1-infected adults with CD4 cell count at least 500 cells/μl were randomized in the ratio 2: 1 to interrupted (I = 27) or continuous (C = 14) HAART for 6 months following an initial IL-2 cycle. Subsequent IL-2 cycles were triggered by CD4 T cell counts less than 90% of baseline. Immune, metabolic, and quality of life indices were compared (Mann–Whitney and Fisher's exact tests), defining noninferiority as a percentage difference (C– I) in treatment success (CD4 T cells ≥90% of baseline at 6 months) with a 95% confidence interval (CI) lower limit greater than −20%.
Results: Demographic and immune parameters were similar between the groups at baseline. Median CD4 T cell count, HIV viral load, and treatment success differed significantly at 6 months (I: 866 cells/μl, 39 389 copies/ml, 48.1%; C: 1246 cells/μl, <50 copies/ml, 92.3%; P ≤ 0.001). Group I was inferior to C (% difference = −44.2%; 95% CI: −64.2%, −11.2%; P = 0.013). Minor statistically significant differences in HgbA1c and energy level occurred at 6 months (I > C). Following HAART interruption, single cases of acute retroviral syndrome, secondary syphilis, non-Hodgkin's lymphoma, and Kaposi's sarcoma recurrence were observed.
Conclusion: IL-2 alone was inferior to IL-2 with HAART in maintaining baseline CD4 T cell counts. HAART interruption had a small impact on metabolic parameters and quality of life.
aNational Institute of Allergy & Infectious Diseases, USA
bCritical Care Medicine Department, USA
cNational Cancer Institute, USA
dClinical Center, National Institutes of Health, Bethesda, Maryland, USA.
Received 11 June, 2008
Revised 10 September, 2008
Accepted 29 September, 2008
Correspondence to Dr Irini Sereti, National Institutes of Health, Building 10-Magnuson Clinical Center, Room 11C103, 10 Center Drive, Bethesda, MD 20982, USA. Tel: +1 301 496 5533; fax: +1 301 402 4097; e-mail: firstname.lastname@example.org