Deep Sequencing of HIV-1 RNA and DNA in Newly Diagnosed Patients with Baseline Drug Resistance Showed No Indications for Hidden Resistance and Is Biased by Strong Interference of Hypermutation

A detailed characterization of drug resistance during darunavir/ritonavir monotherapy highlights a high barrier to the emergence of resistance mutations in protease but identifies alternative pathways of resistance

BACKGROUND

Maintenance monotherapy with ritonavir-boosted darunavir has yielded variable outcomes and is not recommended. Trial samples offer valuable opportunities for detailed studies. We analysed samples from a 48 week trial in Cameroon to obtain a detailed characterization of drug resistance.

METHODS

Following failure of NNRTI-based therapy and virological suppression on PI-based therapy, participants were randomized to ritonavir-boosted darunavir (n = 81) or tenofovir disoproxil fumarate/lamivudine +ritonavir-boosted lopinavir (n = 39). At study entry, PBMC-derived HIV-1 DNA underwent bulk Protease and Reverse Transcriptase (RT) sequencing. At virological rebound (confirmed or last available HIV-1 RNA ≥ 60 copies/mL), plasma HIV-1 RNA underwent ultradeep Protease and RT sequencing and bulk Gag-Protease sequencing. The site-directed mutant T375A (p2/p7) was characterized phenotypically using a single-cycle assay.

RESULTS

NRTI and NNRTI resistance-associated mutations (RAMs) were detected in 52/90 (57.8%) and 53/90 (58.9%) HIV-1 DNA samples, respectively. Prevalence in rebound HIV-1 RNA (ritonavir-boosted darunavir, n = 21; ritonavir-boosted lopinavir, n = 2) was 9/23 (39.1%) and 10/23 (43.5%), respectively, with most RAMs detected at frequencies ≥15%. The resistance patterns of paired HIV-1 DNA and RNA sequences were partially consistent. No darunavir RAMs were found. Among eight participants experiencing virological rebound on ritonavir-boosted darunavir (n = 12 samples), all had Gag mutations associated with PI exposure, including T375N, T375A (p2/p7), K436R (p7/p1) and substitutions in p17, p24, p2 and p6. T375A conferred 10-fold darunavir resistance and increased replication capacity.

CONCLUSIONS

The study highlights the high resistance barrier of ritonavir-boosted darunavir while identifying alternative pathways of resistance through Gag substitutions. During virological suppression, resistance patterns in HIV-1 DNA reflect treatment history, but due to technical and biological considerations, cautious interpretation is warranted.

Genotypic Resistance Testing of HIV-1 DNA in Peripheral Blood Mononuclear Cells

HIV-1 DNA exists in nonintegrated linear and circular episomal forms and as integrated proviruses. In patients with plasma viremia, most peripheral blood mononuclear cell (PBMC) HIV-1 DNA consists of recently produced nonintegrated virus DNA while in patients with prolonged virological suppression (VS) on antiretroviral therapy (ART), most PBMC HIV-1 DNA consists of proviral DNA produced months to years earlier. Drug-resistance mutations (DRMs) in PBMCs are more likely to coexist with ancestral wild-type virus populations than they are in plasma, explaining why next-generation sequencing is particularly useful for the detection of PBMC-associated DRMs. In patients with ongoing high levels of active virus replication, the DRMs detected in PBMCs and in plasma are usually highly concordant. However, in patients with lower levels of virus replication, it may take several months for plasma virus DRMs to reach detectable levels in PBMCs. This time lag explains why, in patients with VS, PBMC genotypic resistance testing (GRT) is less sensitive than historical plasma virus GRT, if previous episodes of virological failure and emergent DRMs were either not prolonged or not associated with high levels of plasma viremia. Despite the increasing use of PBMC GRT in patients with VS, few studies have examined the predictive value of DRMs on the response to a simplified ART regimen. In this review, we summarize what is known about PBMC HIV-1 DNA dynamics, particularly in patients with suppressed plasma viremia, the methods used for PBMC HIV-1 GRT, and the scenarios in which PBMC GRT has been used clinically.

Viral resistance burden and APOBEC editing correlate with virological response in heavily treatment-experienced people living with multi-drug resistant HIV

BACKGROUND

The impact of drug resistance mutational load and APOBEC editing in heavily treatment-experienced (HTE) people living with multidrug-resistant HIV has not been investigated.

MATERIAL AND METHODS

This study explored the HIV-DNA and HIV-RNA mutational load of drug resistance and APOBEC-related mutations through next-generation sequencing (NGS, Illumina MiSeq) in 20 failing HTE participants enrolled in the PRESTIGIO registry.

RESULTS

The patients showed high levels of both HIV-DNA (4.5 [4.0-5.2] log₁₀ copies/10⁶ T-CD4+ cell) and HIV-RNA (4.5 [4.1-5.0] log₁₀ copies/mL) with complex resistance patterns in both compartments. Among the 255 drug-resistant mutations found, 66.3% were concordantly detected in both HIV-DNA and HIV-RNA; 71.3% of mutations were already present in historical Sanger genotypes. At an intra-patient frequency > 5%, a considerable proportion of mutations detected through DNA-NGS were found in historical genotypes but not through RNA-NGS, and few patients had APOBEC-related mutations. Of 14 patients who switched therapy, the five who failed treatment had DNA resistance with higher intra-patient frequency and higher DNA/RNA mutational load in a context of tendentially less pronounced APOBEC editing compared with those who responded.

CONCLUSIONS

Using NGS in HIV-DNA and HIV-RNA together with APOBEC editing evaluation might help to identify HTE individuals with MDR who are more prone to experience virological failure.

Detection of archived lamivudine-associated resistance mutations in virologically suppressed, lamivudine-experienced HIV-infected adults by different genotyping techniques (GEN-PRO study)

BACKGROUND

Previously selected lamivudine resistance-associated mutations (RAMs) may remain archived within the proviral HIV-DNA.

OBJECTIVES

To evaluate the ability of proviral DNA genotyping to detect lamivudine RAMs in HIV-1 virologically suppressed participants; the correlation between Sanger and next generation sequencing (NGS); and predictive factors for detection of lamivudine RAMs in proviral DNA.

METHODS

Cross-sectional study of participants on stable antiretroviral therapy and suppressed for ≥1 year. Analysis of proviral DNA was performed by Sanger sequencing in whole blood and by NGS in PBMCs.

RESULTS

We analysed samples from 102 subjects (52 with and 50 without lamivudine RAMs in historical plasma RNA-genotypes). Among participants with previous lamivudine resistance, Sanger sequencing detected RAMs in 26.9%. Detection rates significantly increased using NGS: 47.9%, 64.6%, 75% and 87.5% with the 20%, 10%, 5% and 1% thresholds, respectively. As for participants without historical lamivudine resistance, Sanger detected the RAMs in 1/49 (2%), and NGS (5% threshold) in 8/45 (17.8%). Multivariate models fitted to the whole population revealed that having a history of lamivudine resistance was a risk factor for detection of lamivudine RAMs by NGS. Among participants with historical lamivudine resistance, multivariate analysis showed that a longer time since HIV diagnosis was associated with persistence of archived mutations by NGS at thresholds of >10% [OR 1.10 (95% CI: 1.00-1.24)] and >5% [OR 1.16 (95% CI: 1.02-1.32)].

CONCLUSIONS

Proviral DNA Sanger sequencing does not detect the majority of historical lamivudine RAMs. NGS increases the sensitivity of detection at lower thresholds, although the relevance of these minority populations with lamivudine RAMs needs further evaluation.

Assessment of intra-sample variability in HIV-1 DNA drug resistance genotyping

BACKGROUND AND OBJECTIVES

HIV-1 drug resistance testing can be performed in proviral DNA. The non-homogenous distribution of viral variants in cells can impact the performance of this method. We assessed the variability of HIV-1 DNA genotyping results in the same blood sample using a next-generation sequencing (NGS) method.

METHODS

For each included patient, a blood sample from a single venipuncture was split into five 1 mL aliquots, which were independently tested in the same run. HIV-1 DNA was quantified in blood samples using real-time PCR, and NGS was performed with the Sentosa platform combined with the Sentosa SQ HIV genotyping Assay.

RESULTS

A total of 60 aliquots from 12 samples (12 patients) were tested. The median age was 45.50 years old, and all patients were treated with antiretrovirals. A significant variability can sometimes be observed in HIV-1 DNA quantification between aliquots from the same sample, with a coefficient of variation ranging from 23% to 89%. The analysis of resistance-associated mutations (RAMs) with a 20% cut-off found some discordances in RAMs profile between aliquots from the same sample for 5, 3 and 3 patients in the reverse transcriptase, protease and integrase genes, respectively. The analysis with a lower cut-off (10%) showed additional mutations, but did not improve the intra-sample concordance.

CONCLUSIONS

There is an intra-sample variability in HIV-1 DNA resistance test results, and repetition may sometimes bring additional information, but the extent of its clinical impact still requires further investigation.

Dolutegravir Plus Lamivudine Two-Drug Regimen: Safety, Efficacy and Diagnostic Considerations for Its Use in Real-Life Clinical Practice-A Refined Approach in the COVID-19 Era

The diagnostic and therapeutic management of the Coronavirus Disease 2019 (COVID-19) pandemic in the HIV population brought some known criticalities (and opportunities) to the forefront, for both those who are facing their first therapeutic line today, and for those already well viro-suppressed. The clinical, socioeconomic, and psychological impact of the COVID-19 pandemic should not affect the long-term care of people living with HIV, which creates an urgent need to optimize the diagnostic and treatment approach to the first-line or switch regimens. The use of dolutegravir plus a lamivudine two-drug regimen is one of the most promising solutions to ease the management of HIV treatment in this difficult period. In this review, we report the most salient features related to the use of this regimen from real-life cohorts, meta-analyses, randomized clinical trials, and studies presented at international conferences up to March 2021. We focused on the diagnostic and clinical-management implications of its use in real life, and how these comply with the contingent historical situation. The issue of the timing and type of diagnostic procedures and the relevance of classical diagnostic tests (such as genotype for resistance detection) is also discussed. According to the currently available results, dolutegravir plus a lamivudine two-drug regimen represents an outstanding tool, whose expected advantages fulfill the current requirements for optimal daily care of our HIV patients.

Switching to bictegravir/emtricitabine/tenofovir alafenamide maintained HIV-1 RNA suppression in participants with archived antiretroviral resistance including M184V/I

Objectives

Studies 1878 and 1844 demonstrated non-inferior efficacy of switching suppressed HIV-1-infected adults to bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) versus continuing boosted PI-based triple regimens or dolutegravir/abacavir/lamivudine (DTG/ABC/3TC). Here, detailed analyses of pre-existing resistance in the two BIC/FTC/TAF switch studies and efficacy at week 48 are described.

Methods

Pre-existing resistance was assessed from historical genotypes (documented resistance to study drugs was excluded) and by retrospective baseline proviral archive DNA genotyping from whole blood. Outcomes were based on HIV-1 RNA at week 48 with missing values imputed using the last on-treatment observation carried forward method.

Results

Cumulative pre-existing resistance data from historical and proviral genotypes were obtained for 95% (543/570) of participants who switched to BIC/FTC/TAF. Altogether, 40% (217/543) had one or more pre-existing primary resistance substitutions in protease, reverse transcriptase and/or integrase. Pre-switch NRTI resistance was detected in 16% (89/543) of BIC/FTC/TAF-treated participants, with M184V or M184I detected by proviral genotyping in 10% (54/543). At week 48, 98% (561/570) of all BIC/FTC/TAF-treated participants versus 98% (213/217) with pre-existing resistance and 96% (52/54) with archived M184V/I had HIV-1 RNA <50 copies/mL. No BIC/FTC/TAF-treated participants developed treatment-emergent resistance to study drugs.

Conclusions

Pre-existing resistance substitutions, notably M184V/I, were unexpectedly common among suppressed participants who switched to BIC/FTC/TAF. High rates of virological suppression were maintained in the overall study population and in those with pre-existing resistance, including M184V/I, for up to 48 weeks of BIC/FTC/TAF treatment with no resistance development. These results indicate that BIC/FTC/TAF is an effective treatment option for suppressed patients, including those with evidence of archived NRTI resistance.

Quality Control of Next-Generation Sequencing-Based HIV-1 Drug Resistance Data in Clinical Laboratory Information Systems Framework

Next-generation sequencing (NGS) in HIV drug resistance (HIVDR) testing has the potential to improve both clinical and public health settings, however it challenges the normal operations of quality management systems to be more flexible due to its complexity, massive data generation, and rapidly evolving protocols. While guidelines for quality management in NGS data have previously been outlined, little guidance has been implemented for NGS-based HIVDR testing. This document summarizes quality control procedures for NGS-based HIVDR testing laboratories using a laboratory information systems (LIS) framework. Here, we focus in particular on the quality control measures applied on the final sequencing product aligned with the recommendations from the World Health Organization HIV Drug Resistance Laboratory Network.

Virological outcomes of boosted protease inhibitor-based first-line ART in subjects harbouring thymidine analogue-associated mutations as the sole form of transmitted drug resistance

Objectives

In subjects with transmitted thymidine analogue mutations (TAMs), boosted PIs (PI/b) are often chosen to overcome possible resistance to the NRTI backbone. However, data to guide treatment selection are limited. Our aim was to obtain firmer guidance for clinical practice using real-world cohort data.

Methods

We analysed 1710 subjects who started a PI/b in combination with tenofovir or abacavir plus emtricitabine or lamivudine, and compared their virological outcomes with those of 4889 patients who started an NNRTI (predominantly efavirenz), according to the presence of ≥1 TAM as the sole form of transmitted drug resistance.

Results

Participants with ≥1 TAM comprised predominantly MSM (213 of 269, 79.2%), subjects of white ethnicity (206 of 269, 76.6%) and HIV-1 subtype B infections (234 of 269, 87.0%). Most (203 of 269, 75.5%) had singleton TAMs, commonly a revertant of T215Y or T215F (112 of 269, 41.6%). Over a median of 2.5 years of follow-up, 834 of 6599 (12.6%) subjects experienced viraemia (HIV-1 RNA >50 copies/mL). The adjusted HR for viraemia was 2.17 with PI/b versus NNRTI-based therapy (95% CI 1.88–2.51; P < 0.001). Other independent predictors of viraemia included injecting drug use, black ethnicity, higher viral load and lower CD4 cell count at baseline, and receiving abacavir instead of tenofovir. Resistance showed no overall impact (adjusted HR 0.77 with ≥1 TAM versus no resistance; 95% CI 0.54–1.10; P = 0.15).

Conclusions

In this cohort, patients harbouring ≥1 TAM as the sole form of transmitted drug resistance gained no apparent virological advantage from starting first-line ART with a PI/b.

Dolutegravir plus lamivudine for maintenance of HIV viral suppression in adults with and without historical resistance to lamivudine: 48-week results of a non-randomized, pilot clinical trial (ART-PRO)

BACKGROUND

We investigated the efficacy of a switch to dolutegravir plus lamivudine in aviremic individuals without evidence of persistent lamivudine resistance-associated mutations in baseline proviral DNA population sequencing.

METHODS

Open-label, single-arm, 48-week pilot trial. HIV-1 infected adults, naïve to integrase inhibitors, with CD4+ above 350 cell/μL and fewer than 50 HIV-1 RNA copies per mL the year prior to study entry switched to dolutegravir plus lamivudine. Participants were excluded if baseline proviral DNA population genotyping detected lamivudine resistance-associated mutations. To detect resistance minority variants, proviral DNA next-generation sequencing was retrospectively performed from baseline samples. Primary efficacy endpoint was proportion of participants with fewer than 50 HIV-1 RNA copies per mL at week 48. Safety and tolerability outcomes were incidence of adverse events and treatment discontinuations. ART-PRO is registered with ClinicalTrials.gov, NCT03539224.

FINDINGS

41 participants switched to dolutegravir plus lamivudine, 21 with lamivudine resistance mutations in historical plasma genotypes. Baseline next-generation sequencing detected lamivudine resistance mutations (M184V/I and/or K65R/E/N) over a 5% threshold in 15/21 (71·4%) and 3/20 (15%) of participants with and without history of lamivudine resistance, respectively. At week 48, 92·7% of participants (38/41) had fewer than 50 HIV-1 RNA copies per mL. There were no cases of virologic failure. Three participants with historical lamivudine resistance were prematurely discontinued from the study (2 protocol violations, one adverse event). Ten participants (4 in the group with historical lamivudine resistance) had a transient viral rebound, all resuppressed on dolutegravir plus lamivudine. There were 28 drug-related adverse events, only one leading to discontinuation.

INTERPRETATION

In this pilot trial, dolutegravir plus lamivudine was effective in maintaining virologic control despite past historical lamivudine resistance and presence of archived lamivudine resistance-associated mutations detected by next generation sequencing. Further studies are needed to confirm our results.

FUNDING

Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III PI16/00837-PI16/00678.

Analysis of unusual and signature APOBEC-mutations in HIV-1 pol next-generation sequences

Introduction

At low mutation-detection thresholds, next generation sequencing (NGS) for HIV-1 genotypic resistance testing is susceptible to artifactual detection of mutations arising from PCR error and APOBEC-mediated G-to-A hypermutation.

Methods

We analyzed published HIV-1 pol Illumina NGS data to characterize the distribution of mutations at eight NGS mutation detection thresholds: 20%, 10%, 5%, 2%, 1%, 0.5%, 0.2%, and 0.1%. At each threshold, we determined proportions of amino acid mutations that were unusual (defined as having a prevalence <0.01% in HIV-1 group M sequences) or signature APOBEC mutations.

Results

Eight studies, containing 855 samples, in the NCBI Sequence Read Archive were analyzed. As detection thresholds were lowered, there was a progressive increase in the proportion of positions with usual and unusual mutations and in the proportion of all mutations that were unusual. The median proportion of positions with an unusual mutation increased gradually from 0% at the 20% threshold to 0.3% at the 1% threshold and then exponentially to 1.3% (0.5% threshold), 6.9% (0.2% threshold), and 23.2% (0.1% threshold). In two of three studies with available plasma HIV-1 RNA levels, the proportion of positions with unusual mutations was negatively associated with virus levels. Although the complete set of signature APOBEC mutations was much smaller than that of unusual mutations, the former outnumbered the latter in one-sixth of samples at the 0.5%, 1%, and 2% thresholds.

Conclusions

The marked increase in the proportion of positions with unusual mutations at thresholds below 1% and in samples with lower virus loads suggests that, at low thresholds, many unusual mutations are artifactual, reflecting PCR error or G-to-A hypermutation. Profiling the numbers of unusual and signature APOBEC pol mutations at different NGS mutation detection thresholds may be useful to avoid selecting a threshold that is too low and poses an unacceptable risk of identifying artifactual mutations.

Routine drug resistance testing in HIV-1 proviral DNA, using an automated next- generation sequencing assay

BACKGROUND

HIV-1 DNA genotypic drug resistance testing is increasingly performed to guide treatment switching or simplification in controlled patients. The Sentosa NGS platform is a fully automated system marketed for drug resistance testing on HIV-1 RNA samples.

OBJECTIVES

The aim of this study was to evaluate this automated NGS solution for routine resistance genotypic resistance testing in proviral HIV-1 DNA.

STUDY DESIGN

Sanger sequencing (SS) of the reverse transcriptase (RT), protease (PR) and integrase (IN) genes was performed using the French ANRS protocol. NGS was performed retrospectively on frozen samples, using the Sentosa platform combined with the Sentosa SQ HIV genotyping Assay.

RESULTS

A total of 77 samples were run once using NGS. A successful sequencing of the three HIV-1 genes (RT, PR, IN) was obtained for 45 samples. The number of cumulated RAMs was 179, 185 and 219 with SS, NGS 20% and NGS 10% respectively; however most of them were minor mutations in the PR region. The mutation detection rate was similar between SS and NGS 20%. Several discordances were observed between both methods in the RT and PR regions, mainly due to the use of different DNA extracts, and hypermutation.

CONCLUSIONS

HIV-1 DNA genotypic resistance testing can be performed with the Sentosa platform. Few technical optimizations are still needed to include the extraction step and to improve the sequencing efficiency.

Routine drug resistance testing in proviral HIV-1 DNA: Prevalence of stop codons and hypermutation, and associated factors

We investigated the presence of stop codons (SC) and/or hypermutation (HM) in HIV-1 DNA sequences generated for routine drug resistance testing in proviral HIV-1 DNA, and sought for associated factors. At least one SC was identified in 6.2% of HIV-1 DNA sequences, among which 54.8% were hypermutated. The defective virus group (SC w/o HM) was similar to the non-SC group regarding the characteristics of HIV-1 infection, and before drug exposure. In addition, the HIV-1 DNA levels were not different between both groups. Sequences with SC/HM displayed a higher proportion of RAMs. The impact of the SC/HM associated RAMs on clinical responses requires further investigation.

Bioinformatic data processing pipelines in support of next-generation sequencing-based HIV drug resistance testing: the Winnipeg Consensus

INTRODUCTION

Next-generation sequencing (NGS) has several advantages over conventional Sanger sequencing for HIV drug resistance (HIVDR) genotyping, including detection and quantitation of low-abundance variants bearing drug resistance mutations (DRMs). However, the high HIV genomic diversity, unprecedented large volume of data, complexity of analysis and potential for error pose significant challenges for data processing. Several NGS analysis pipelines have been developed and used in HIVDR research; however, the absence of uniformity in data processing strategies results in lack of consistency and comparability of outputs from different pipelines. To fill this gap, an international symposium on bioinformatic strategies for NGS-based HIVDR testing was held in February 2018 in Winnipeg, Canada, convening laboratory scientists, bioinformaticians and clinicians involved in four recently developed, publicly available NGS HIVDR pipelines. The goal of this symposium was to establish a consensus on effective bioinformatic strategies for NGS data management and its use for HIVDR reporting.

DISCUSSION

Essential functionalities of an NGS HIVDR pipeline were divided into five analytic blocks: (1) NGS read quality control (QC)/quality assurance (QA); (2) NGS read alignment and reference mapping; (3) HIV variant calling and variant QC; (4) NGS HIVDR reporting; and (5) extended data applications and additional considerations for data management. The consensuses reached among the participants on all major aspects of these blocks are summarized here. They encompass not only recommended data management and analysis strategies, but also detailed bioinformatic approaches that help ensure accuracy of the derived HIVDR analysis outputs for both research and potential clinical use.

CONCLUSIONS

While NGS is being adopted more broadly in HIVDR testing laboratories, data processing is often a bottleneck hindering its generalized application. The proposed standardization of NGS read QC/QA, read alignment and reference mapping, variant calling and QC, HIVDR reporting and relevant data management strategies in this "Winnipeg Consensus" may serve as a starting guideline for NGS HIVDR data processing that informs the refinement of existing pipelines and those yet to be developed. Moreover, the bioinformatic strategies presented here may apply more broadly to NGS data analysis of microbes harbouring significant genomic diversity.

RNA and DNA Sanger sequencing versus next-generation sequencing for HIV-1 drug resistance testing in treatment-naive patients

Background

Sanger sequencing of plasma RNA is the standard method for HIV-1 drug resistance testing in treatment-naive patients, but is limited by the non-detection of resistance-associated mutations (RAMs) with prevalence below approximately 20%.

Objectives

We compared RNA and DNA Sanger sequencing (RSS and DSS) with RNA next-generation sequencing (NGS) for RAM detection in HIV-1 reverse transcriptase (RT), protease (PR) and integrase (IN) genes.

Methods

Sanger sequencing was performed on RNA and DNA, following the recommendations of the French Agency for AIDS Research (ANRS). NGS was performed on RNA using the HIV-1 Drug Resistance Assay, v. 3.0 (Roche) on the 454 GS Junior sequencer. The IAS-USA list was used to identify RAMs. ANRS, Rega and Stanford algorithms were used for drug resistance interpretation.

Results

The study included 48 ART-naive patients. The number of patients with at least one major RAM was 3, 3, 4 and 8 when using RSS, DSS, NGS 20% and NGS 5%, respectively. Numerous minor mutations were detected in patients, especially in the protease gene. None of the methods detected any major mutation in the integrase gene. Overall, the mutation detection rate was similar between RSS and DSS, and higher with NGS 20%. Differences in drug resistance interpretation were found between algorithms. No impact of the minority RAMs detected by NGS was found on the short-term treatment outcome.

Conclusions

DSS does not clearly improve the detection of RAMs in ART-naive patients, as compared with RSS. NGS allows detection of additional minority RAMs; however, their clinical relevance requires further investigation.

Comparison of an In Vitro Diagnostic Next-Generation Sequencing Assay with Sanger Sequencing for HIV-1 Genotypic Resistance Testing

The ability of next-generation sequencing (NGS) technologies to detect low frequency HIV-1 drug resistance mutations (DRMs) not detected by dideoxynucleotide Sanger sequencing has potential advantages for improved patient outcomes. We compared the performance of an in vitro diagnostic (IVD) NGS assay, the Sentosa SQ HIV genotyping assay for HIV-1 genotypic resistance testing, with Sanger sequencing on 138 protease/reverse transcriptase (RT) and 39 integrase sequences. The NGS assay used a 5% threshold for reporting low-frequency variants. The level of complete plus partial nucleotide sequence concordance between Sanger sequencing and NGS was 99.9%. Among the 138 protease/RT sequences, a mean of 6.4 DRMs was identified by both Sanger and NGS, a mean of 0.5 DRM was detected by NGS alone, and a mean of 0.1 DRM was detected by Sanger sequencing alone. Among the 39 integrase sequences, a mean of 1.6 DRMs was detected by both Sanger sequencing and NGS and a mean of 0.15 DRM was detected by NGS alone. Compared with Sanger sequencing, NGS estimated higher levels of resistance to one or more antiretroviral drugs for 18.2% of protease/RT sequences and 5.1% of integrase sequences. There was little evidence for technical artifacts in the NGS sequences, but the G-to-A hypermutation was detected in three samples. In conclusion, the IVD NGS assay evaluated in this study was highly concordant with Sanger sequencing. At the 5% threshold for reporting minority variants, NGS appeared to attain a modestly increased sensitivity for detecting low-frequency DRMs without compromising sequence accuracy.

Prevalence of Drug-Resistant Minority Variants in Untreated HIV-1-Infected Individuals With and Those Without Transmitted Drug Resistance Detected by Sanger Sequencing

Minority variant human immunodeficiency virus type 1 (HIV-1) nonnucleoside reverse transcriptase inhibitor (NNRTI) resistance mutations are associated with an increased risk of virological failure during treatment with NNRTI-containing regimens. To determine whether individuals to whom variants with isolated NNRTI-associated drug resistance were transmitted are at increased risk of virological failure during treatment with a non-NNRTI-containing regimen, we identified minority variant resistance mutations in 33 individuals with isolated NNRTI-associated transmitted drug resistance and 49 matched controls. We found similar proportions of overall and nucleoside reverse transcriptase inhibitor-associated minority variant resistance mutations in both groups, suggesting that isolated NNRTI-associated transmitted drug resistance may not be a risk factor for virological failure during treatment with a non-NNRTI-containing regimen.