CD4 and coinfection: The study cohort consisted of 26 AIDS patients with relatively high plasma viral loads (median 10,935 copies/ml, range <50–2,210,000) and low CD4 counts (median 80 cells/μl, range 3–261), together with a high frequency of intravenous drug abuse (IVDU) (65%), HCV co-infection (50%), and HIV-associated dementia (HAD) (50%).