CD4 and AIDS: However, these patients represent two different types of naive subjects because those of group II still maintained a quite conserved immune system (CD4+ cell count >350/μL) and did not need antiretroviral therapy according to the current guidelines for the diagnosis and treatment of HIV-1 infection, whereas those of group I at T0 were patients with a number of CD4+ T cells <350/μL or with clinical AIDS-defining conditions at diagnosis.