IL-7 and Flt-3L plasma levels are increased during highly active antiretroviral therapy-associated IL-2 therapy.

IL-2 is used in conjunction with highly active antiretroviral therapy to increase the CD4 cell count in HIV-positive patients. The mechanisms involved remain ill-defined. Here we show that during the first cycle of IL-2 therapy, IL-7 and Flt-3L plasma levels are increased, whereas levels of stem cell factor are unchanged. This supports the hypothesis that aside from stimulating CD4 T cells IL-2 may also indirectly affect lymphocyte production through the stimulation of lymphopoietic cytokines.