Centers for Disease Control and Prevention Class C AIDS was present in 18.8% of patients, HIV-1 RNA ≥ 100,000 copies/mL in 43.2%, CD4 count < 200 cells/mm3 in 38.2% and < 50 cells/mm3 in 10.4%, and hepatitis C virus co-infection in 18.6%. This evidence concerns the gene CD4 and AIDS.