CD4 and AIDS: Patients on ART with poor CD4+ cell count recovery, as defined by either an increase in CD4+ cell counts from baseline (e.g., < 50 or < 100 cells/mm3) or a failure to achieve a CD4+ cell count over specific thresholds (e.g., 200, 350 or 500 cells/mm3), are at greater risk of AIDS and serious non-AIDS morbidity and mortality [8, 12–16].