Effect of Adjunct Hydroxyurea on Helper T Cell Immunity in HIV Type 1-Infected Patients with Virological Suppression

Hydroxyurea (HU) has preferential activity in virus reservoirs not effectively targeted by current antiretroviral drug regimens, but concern for potential toxicity has precluded its routine use. The effect of adjunct HU on T cell proliferative responses and phenotypic markers was examined in a randomized study of 39 chronically HIV-1-infected patients with virological suppression on potent antiretroviral therapy. While patients in the HU arm showed modest declines in the median CD4⁺ T cell counts (total, –151 cells/mm³; naive, –91 cells/mm³), no significant differences were noted in the Candida, HIV-1 p24, and HIV-1 gp160 responses between the treatment arms following 24 weeks of therapy. In conclusion, although adjunct HU was associated with modest declines in the CD4⁺ T cell counts, there was no significant adverse effect on helper T cell function. Further trials to address the role of HU in HIV-1 treatment may be appropriate after careful selection of HU dose and the adjunct drugs to avoid nonhematological toxicity.