In the NNRTI group, two patients (patients 11 and 17) of 10 who received at least 12 months of EFV-based HAART showed new key mutations (Y188Y/H and M184M/I), while one (patient 36) in the PI

group and one naïve patient (patient 3) had a new key RT mutation (M184I). All new key mutations except one (in patient 36) were only present in the CD4 cells. Patient 36, who received d4T, ABC and LPV/r combination therapy for 1 year before changing to a 3TC, TDF and LPV/r regimen, showed a new key mutation (M184I) after 18 months of follow-up selleckchem in the plasma RNA but not in the proviral DNA. Thus, monitoring of the evolution of drug resistance mutations in treated patients by direct sequencing of HIV-1 proviral DNA in purified CD4

cells revealed new mutations, with moderately good agreement between pre- and post-treatment DNA mutation patterns. In patients who remained treatment-naïve, almost no evolution was observed in mutations detected in plasma RNA or cell DNA. After therapy initiation we noted the persistence of HIV-1 drug resistance mutations in proviral DNA from purified CD4 cells PXD101 chemical structure compared with plasma viral RNA at baseline. In our small cohort, 30 of 32 treated patients showed an undetectable plasma viral load after at least 12 months and up to 44 months of follow-up. Patients with pre-existing resistance mutations had a good response to all types of HAART, but none of them underwent combination therapy with the targeted drug. One interesting question was whether the PD184352 (CI-1040) DNA test might be useful to guide therapy switches in patients with suppressed viral load. This was addressed by comparing the prevalences of detected mutations in pretreatment

RNA and post-treatment DNA (59 and 78%, respectively). A statistically significant proportion of mutations (19%) were detected in the DNA compared to the pretreatment RNA. The data demonstrated that sequencing DNA is possible and the recommended RNA sequencing might miss some mutations. In the comparison of pretreatment RNA with post-treatment DNA using kappa statistics, a moderately good agreement was found in terms of mutations detected and only a fairly good agreement in terms of predicting drug activity because of the accumulation of new mutations in the DNA. In patients with detectable viraemia, no new DNA mutations were detected and the viral loads were too low to enable RNA genotyping to be performed (patients 16, 19 and 21 with 556, 150 and 80 copies/mL, respectively). Therefore, we could not conclude that the standard method had underestimated the accumulation of mutations as the test was only possible on cell DNA samples. Transmission of drug-resistant HIV-1 strains and reduced susceptibility of viruses derived from untreated patients have been documented.