Inferiority of IL-2 alone versus IL-2 with HAART in maintaining CD4 T cell counts during HAART interruption: a...

Area of Science:

• Immunology
• Virology
• Clinical Medicine

Background:

• Chronic HIV infection requires ongoing management to maintain immune function.
• Highly active antiretroviral therapy (HAART) is the standard of care for HIV.
• Interleukin-2 (IL-2) has been explored as an adjunct therapy to improve immune reconstitution.

Purpose of the Study:

• To assess if IL-2 can preserve CD4 T cell counts during a 6-month interruption of HAART in HIV patients.
• To compare the efficacy of IL-2 with HAART interruption versus continuous HAART in maintaining immune parameters.

Main Methods:

• A prospective, randomized, open-label, phase II noninferiority trial was conducted.
• 41 HIV-1 infected adults with CD4 counts ≥500 cells/µL were randomized to interrupted HAART (n=27) or continuous HAART (n=14) after an IL-2 cycle.
• Treatment success was defined as CD4 T cells ≥90% of baseline at 6 months; noninferiority required a 95% CI lower limit > -20%.

Main Results:

• At 6 months, median CD4 counts were 866 cells/µL for interrupted HAART and 1246 cells/µL for continuous HAART (P < 0.001).
• Treatment success rates were 48.1% for interrupted HAART versus 92.3% for continuous HAART, indicating inferiority (P = 0.013).
• Minor differences in HgbA1c and energy levels were observed; adverse events included acute retroviral syndrome and opportunistic infections.

Conclusions:

• IL-2 alone is inferior to IL-2 combined with continuous HAART for maintaining CD4 T cell counts in HIV patients.
• HAART interruption, even with IL-2, leads to significant immune decline and potential opportunistic infections.
• While HAART interruption had minimal impact on metabolic parameters and quality of life, the immunological consequences are substantial.