We randomly assigned HIV-positive adults who had a CD4 + count of more than 500 cells per cubic millimeter to start antiretroviral therapy immediately ( immediate-initiation group ) or to defer it until the CD4 + count decreased to 350 cells per cubic millimeter or until the development of the acquired immunodeficiency syndrome ( AIDS ) or another condition that dictated the use of antiretroviral therapy ( deferred-initiation group ) .