CD4+ T cell count and plasma HIV-1 viral load
Fasting venous blood samples were collected. CD4+ T cell count (cells/L) and HIV-1 viral load (HIV-RNA, copies/mL) were determined in all HIV-infected subjects. Absolute CD4+T cell numbers were determined using an Epics XL-MCL flow cytometer (Beckman Coulter, Brea, CA, USA). Plasma HIV-1 RNA levels were determined using the COBAS Taqman HIV-1 test (Roche, Branchburg, New Jersey, USA) according to the manufacturer’s instructions. The detection limit was 40 HIV RNA copies/mL.