Genotypic Resistance of Archived and Circulating Viral Strains in the Blood of Treated HIV-Infected Individuals

Abstract

The aim of this study was to evaluate patterns of antiretroviral resistance of HIV-1 in peripheral blood mononuclear cells (PBMCs) and in the plasma of patients whose therapeutic regimen is failing. Plasma and PBMC samples were collected from 95 HIV-infected patients undergoing long-term treatment. Genotyping of the reverse transcriptase (RT) and protease genes of HIV-1 was undertaken using the fluorescent dideoxy-terminator method. Comparison of the amino acid sequence of the RT and protease genes in cell-associated variants of HIV-1 with that of the plasma revealed that 62 of the 95 patients' samples tested exhibited different genotypic resistance patterns (discordant samples [DSs]). In 27% of samples, the patterns of resistance detected were concordant in both compartments. In 51% of DSs, the greatest number of mutations was found in plasma; however, in 37% of DSs, greater numbers of mutations were found in PBMC DNA. The HIV mutation patterns detected in plasma do not necessarily reflect those found in the cell-associated compartment. The observation that the cellular compartment may contain an archive of the resistance variant makes this reservoir an interesting substrate for analysis of the "resistance potential" in a given patient.

Transmission of HIV‐1 Drug‐Resistant Variants: Prevalence and Effect on Treatment Outcome

“…In 6 patients, we were only able to detect mutations from the PBMC samples, some of them being high-level resistance mutations. However, the number of mutations in the PBMC compartment did not per se exceed the number in the plasma compartment, but as expected the inclusion of both strengthened the overall interpretation of drug resistance level, which is in agreement with previous observations [17,18]. Thus, the different observations in the plasma and PBMC compartment is likely attributed to stochastic effects, given that the detection of minority variants is at the limit of detection of sensitivity.…”

“…In recent years, different estimates of the prevalence of transmitted drug resistance (TDR) in Europe and North America have been reported, ranging from as peripheral blood mononuclear cell (PBMC) population. An approach addressing these 2 factors may provide a more accurate estimate of the frequency of TDR [17][18][19]; as a consequence of increased sensitivity, the actual prevalence of TDR may be higher than that provided by current published estimates.…”

Comparison of resistance mutation patterns in historical plasma HIV RNA genotypes with those in current proviral HIV DNA genotypes among extensively treated patients with suppressed replication

“…The efficacy of switch drugs for patients receiving a virologically effective regimen depends mainly on the number and nature of resistance mutations archived in the pro- viral reservoir following previous therapeutic failures [2][3][4][5][6][7]10,11]. Viraemia is suppressed by the antiretroviral regimen in these patients, so resistance genotyping must be performed only on cell-associated HIV-1 DNA.…”

“…Interestingly, a longitudinal analysis has shown that resistance mutations emerge in plasma HIV-1 more than 1 year before they are found in peripheral blood mononuclear cells (PBMCs) [2,22]. In contrast, because genetic changes in cellular proviruses occur more slowly than in plasma viruses, which are more sensitive to selective pressure, mutations persisted longer in proviral DNA [6,11,14]. Another hypothesis is that, in patients on effective HAART, cells infected by archived resistant provirus could be diluted by more recent uninfected cells and therefore be less readily detectable.…”

Evaluation of HIV-1 resistance to antiretroviral drugs among 150 patients after six months of therapeutic interruption

“…22,23 This, combined with the stability of DNA compared with RNA, and the fact that HIV DNA recovered from the proviral compartment can reliably be used for the determination of drug resistance mutations in patients receiving ART 24 -28 influenced our decision to use proviral DNA in this study.…”