CD4 and AIDS: Patients in group 1 (pre-ART CD4+ T cell count ≤ 200/mm3) were slightly older than patients in group 2 (pre-ART CD4+ T cell count > 200/mm3) (38.5 versus 37.0 years, p = 0.09) and, as expected, had experienced more AIDS-defining events (31.8% versus 3.5%, p<0.0001).