Significant reduction in HIV-1 plasma viral load but not in proviral infected cells during sub-optimal antiretroviral therapy

Attempts to eradicate HIV infection through highly active antiretroviral th erapy (HAART) in the very early stages of the infection have failed due to the resumption of viral replication from unknown reservoirs. It has been po stulated that antiretroviral therapy capable of suppressing viral replicati on, as shown by reduction of HIV-RNA copies in plasma and lymph nodes, shou ld have less effect on the number of HIV-DNA carrying cells in the same dis tricts. To test this hypothesis, plasma viremia and the proportion of provi rally infected cells in peripheral blood and in lymph nodes were measured i n patients at 3 and 6 months of treatment with zidovudine plus lamivudine. All patients showed a significant decrease in plasma viremia at 3 months th at was maintained at 6 months (mean values of 1.6 +/- 0.6 log(10) from base line). Conversely the proportion of HIV-DNA carrying cells slightly decline d at 3 months but remained substantially stable thereafter both in peripher al blood and in lymph nodes. Taken together these data suggest that this th erapeutic regimen, although sub-optimal, is effective in significantly redu cing the virus production by productively infected cells but does not seem to substantially affect the load of provirally infected cells.