BETHESDA, MdThe addition of interleukin-2 (IL-2) to standard
anti-retroviral therapy significantly improved CD4 cell response in
HIV-infected patients, reported Richard T. Davey Jr, MD, of the
National Institute of Allergy and Infectious Diseases.
This randomized, controlled multi-center trial, conducted from April
1996 through April 1998, included 78 adult outpatients with HIV and
baseline CD4 cell counts of 200 to 500 × 106/L and
baseline HIV-1 RNA levels of fewer than 10,000 copies/mL. Patients
were randomized to receive subcutaneous IL-2, given in 5-day courses
every 8 weeks at a starting dosage of 7.5 mIU twice daily plus
antiretroviral therapy or antiretroviral therapy alone.
At 1 year, patients who received IL-2 had a mean percentage increase
in CD4 cell counts of 112%, compared with 18% for the group receiving
antiretroviral therapy alone (P < .001). CD4 cell
percen-tages rose from a mean of 20% to 32% in the combination
therapy group and from 20% to 23% in the group receiving
antiretroviral therapy only (P < .001).
Of 30 evaluable patients receiving IL-2, 20 (67%) achieved a final
viral load of fewer than 50 copies/mL, compared with 13 (36%) of 36
control patients (P = .02) (JAMA 284:183-189, 2000).
Toxic effects were common among patients who received IL-2, the
researchers said, and were managed with anti-pyretics, hydration,
rest, and dosage reduction as needed.
Clinical endpoint trials will be necessary to determine whether
the enhanced viral suppression and CD4 cell increases associated with
IL-2 therapy will translate into improved clinical outcomes,
the researchers said.