HIV infected macrophages isolated from HIV plus patients with undetectableviral load undergoing highly active antiretroviral therapy.

A new method of culture of peripheral blood leukocytes (PBMC) from HIV+ pat ients, in the absence of exogenous stimuli (allogeneic cells or cytokines) (PBMC w/s) was used for the detection of persistent viral infection in HIV patients who had undergone successful highly active antiretroviral therapy (HAART) lowering their viral burden to undetectable levels (< 50 RNA copies /ml). Infected cells were always of the monocyte/macrophage lineage (M). No infection could be detected in these patients using the classical system ( co-culture with HIV-CMP activated with PHA and IL-2). Differences in the cl ass of target cells (higher proportion of proliferating M and CCR5 expressi ng cells in the PBMC w/s system than in PBMC-PHA cultures) may determine th e relative sensitivity of each technique to achieve successful isolation of HIV from different patients.