Virological response to HIV-1 nucleoside/nucleotide reverse transcriptase inhibitors-based, tenofovir DF-including regimens in the ANRS Aquitaine Cohort

HIV-1 nucleoside/tide reverse transcriptase inhibitors (NRTI)-only based, comprising tenofovir DF(TDF) have been shown to lead to high rates of virological failures (VF), mainly in patients on first-line combination therapy. We wished to investigate the virological response to these regimens in a large cohort of antiretroviral (ARV)-treated patients.Patients followed-up in the Aquitaine Cohort in 2001-2003 and who had received NRTI-based, TDF-including regimens for at least 3 months were included. The VF was defined as: (i) a decrease in plasma HIV-1 RNA0.5 log(10)copies/ml between M0 and M3; or (ii) a plasma HIV-1 RNA50 copies/ml at M3 in patients with plasma HIV-1 RNA50 copies/ml at M0. The baseline RT genotype was determined in a subgroup of patients.Within 121 patients (95% ARV-experienced) who received either lamivudine (3TC)/didanosine (DDI)/TDF (n=48), or abacavir (ABC)/3TC/TDF (n=14), or 3TC/zidovudine (ZDV)/TDF (n=27), or 3TC/ZDV/ABC/TDF (n=20), or DDI/ABC/TDF (n=12), the ABC/3TC/TDF and DDI/ABC/TDF combinations were associated with the highest frequencies of VF. In contrast the use of ZDV was related to a better virological response. The baseline RT genotype was also predictive of the virological outcome.NRTI-based, TDF-including therapies can lead to high rates of VF both in ARV-naïve and in ARV-experienced patients. Our data strongly suggest the interest of associating ZDV and TDF in these regimens.