Nadir CD4+ T cell count predicts response to subcutaneous recombinant interleukin-2

Area of Science:

• Immunology
• Virology
• Clinical Medicine

Background:

• The Community Program for Clinical Research on AIDS 059 study investigated treatments for human immunodeficiency virus (HIV).
• Antiretroviral therapy (ART) is standard care, but adjunct therapies are explored to improve immune reconstitution.
• Recombinant interleukin-2 (rIL-2) has been studied for its potential to boost CD4+ T-cell counts in HIV-infected individuals.

Purpose of the Study:

• To identify factors predicting treatment response to intermittent subcutaneous rIL-2 in HIV-infected individuals receiving ART.
• To analyze the association between baseline characteristics and CD4+ cell count changes after rIL-2 administration.

Main Methods:

• Secondary analysis of a multicenter trial (CPCR A 059) involving HIV-infected individuals with CD4+ counts >=300 cells/mm3.
• Participants received ART with or without rIL-2; this analysis focused on rIL-2 recipients completing 3 cycles.
• Multivariate analysis examined predictors of CD4+ cell count change from baseline to 1 month post-cycle 3, including demographics, rIL-2 dose, HIV load, and CD4+ counts (baseline and nadir).

Main Results:

• The combination of race and sex (P=.027) and nadir CD4+ cell count (P=.005) were significant predictors of CD4+ cell count response.
• Higher nadir CD4+ cell counts were associated with a greater increase in CD4+ cell count.
• Baseline CD4+ cell count did not significantly predict response to rIL-2 therapy.

Conclusions:

• Demographic factors (race, sex) and prior immune status (nadir CD4+ count) influence response to rIL-2 therapy in HIV patients.
• The findings suggest that severe CD4+ cell depletion during HIV infection may lead to irreversible immunologic damage.
• Nadir CD4+ cell count is a critical factor in predicting immune recovery potential during adjunctive therapy for HIV.