scholarly journals Analysis of Low-Frequency Mutations Associated with Drug Resistance to Raltegravir before Antiretroviral Treatment

2010 ◽  
Vol 55 (3) ◽  
pp. 1114-1119 ◽  
Author(s):  
Jia Liu ◽  
Michael D. Miller ◽  
Robert M. Danovich ◽  
Nathan Vandergrift ◽  
Fangping Cai ◽  
...  

ABSTRACTRaltegravir is highly efficacious in the treatment of HIV-1 infection. The prevalence and impact on virologic outcome of low-frequency resistant mutations among HIV-1-infected patients not previously treated with raltegravir have not been fully established. Samples from HIV treatment-experienced patients entering a clinical trial of raltegravir treatment were analyzed using a parallel allele-specific sequencing (PASS) assay that assessed six primary and six secondary integrase mutations. Patients who achieved and sustained virologic suppression (success patients,n= 36) and those who experienced virologic rebound (failure patients,n= 35) were compared. Patients who experienced treatment failure had twice as many raltegravir-associated resistance mutations prior to initiating treatment as those who achieved sustained virologic success, but the difference was not statistically significant. The frequency of nearly all detected resistance mutations was less than 1% of viral population, and the frequencies of mutations between the success and failure groups were similar. Expansion of pre-existing mutations (one primary and five secondary) was observed in 16 treatment failure patients in whom minority resistant mutations were detected at baseline, suggesting that they might play a role in the development of drug resistance. Two or more mutations were found in 13 patients (18.3%), but multiple mutations were not present in any single viral genome by linkage analysis. Our study demonstrates that low-frequency primary RAL-resistant mutations were uncommon, while minority secondary RAL-resistant mutations were more frequently detected in patients naïve to raltegravir. Additional studies in larger populations are warranted to fully understand the clinical implications of these mutations.

2016 ◽  
Vol 60 (6) ◽  
pp. 3380-3397 ◽  
Author(s):  
Fred Kyeyune ◽  
Richard M. Gibson ◽  
Immaculate Nankya ◽  
Colin Venner ◽  
Samar Metha ◽  
...  

Most patients failing antiretroviral treatment in Uganda continue to fail their treatment regimen even if a dominant drug-resistant HIV-1 genotype is not detected. In a recent retrospective study, we observed that approximately 30% of HIV-infected individuals in the Joint Clinical Research Centre (Kampala, Uganda) experienced virologic failure with a susceptible HIV-1 genotype based on standard Sanger sequencing. Selection of minority drug-resistant HIV-1 variants (not detectable by Sanger sequencing) under antiretroviral therapy pressure can lead to a shift in the viral quasispecies distribution, becoming dominant members of the virus population and eventually causing treatment failure. Here, we used a novel HIV-1 genotyping assay based on deep sequencing (DeepGen) to quantify low-level drug-resistant HIV-1 variants in 33 patients failing a first-line antiretroviral treatment regimen in the absence of drug-resistant mutations, as screened by standard population-based Sanger sequencing. Using this sensitive assay, we observed that 64% (21/33) of these individuals had low-frequency (or minority) drug-resistant variants in the intrapatient HIV-1 population, which correlated with treatment failure. Moreover, the presence of these minority HIV-1 variants was associated with higher intrapatient HIV-1 diversity, suggesting a dynamic selection or fading of drug-resistant HIV-1 variants from the viral quasispecies in the presence or absence of drug pressure, respectively. This study identified low-frequency HIV drug resistance mutations by deep sequencing in Ugandan patients failing antiretroviral treatment but lacking dominant drug resistance mutations as determined by Sanger sequencing methods. We showed that these low-abundance drug-resistant viruses could have significant consequences for clinical outcomes, especially if treatment is not modified based on a susceptible HIV-1 genotype by Sanger sequencing. Therefore, we propose to make clinical decisions using more sensitive methods to detect minority HIV-1 variants.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Alison F Feder ◽  
Soo-Yon Rhee ◽  
Susan P Holmes ◽  
Robert W Shafer ◽  
Dmitri A Petrov ◽  
...  

In the early days of HIV treatment, drug resistance occurred rapidly and predictably in all patients, but under modern treatments, resistance arises slowly, if at all. The probability of resistance should be controlled by the rate of generation of resistance mutations. If many adaptive mutations arise simultaneously, then adaptation proceeds by soft selective sweeps in which multiple adaptive mutations spread concomitantly, but if adaptive mutations occur rarely in the population, then a single adaptive mutation should spread alone in a hard selective sweep. Here, we use 6717 HIV-1 consensus sequences from patients treated with first-line therapies between 1989 and 2013 to confirm that the transition from fast to slow evolution of drug resistance was indeed accompanied with the expected transition from soft to hard selective sweeps. This suggests more generally that evolution proceeds via hard sweeps if resistance is unlikely and via soft sweeps if it is likely.


2020 ◽  
Vol 30 (1) ◽  
Author(s):  
Mabeya Sepha ◽  
Nyamache Anthony ◽  
Ngugi Caroline ◽  
Nyerere Andrew ◽  
Lihana Raphael

BACKGROUND: Antiretroviral therapy containing an integrase strand transfer inhibitor plus two Nucleoside Reverse Transcriptase inhibitors has now been recommended for treatment of HIV-1-infected patients. This thus determined possible pre-existing integrase resistance associated mutations in the integrase gene prior to introduction of integrase inhibitors combination therapy in Kenya.METHODS: Drug experienced HIV patients were enrolled at Kisii Teaching and Referral in Kenya. Blood specimens from (33) patients were collected for direct sequencing of HIV-1 polintegrase genes. Drug resistance mutations were interpreted according to the Stanford algorithm and phylogenetically analysed using insilico tools.RESULTS: From pooled 188 Kenyan HIV integrase sequences that were analysed for drug resistance, no major mutations conferring resistance to integrase inhibitors were detected. However, polymorphic accessory mutations associated with reduced susceptibility of integrase inhibitors were observed in low frequency; M50I (12.2%), T97A (3.7%), S153YG, E92G (1.6%), G140S/A/C (1.1%) and E157Q (0.5%). Phylogenetic analysis (330 sequences revealed that HIV-1 subtype A1 accounted for majority of the infections, 26 (78.8%), followed by D, 5 (15.2%) and C, 2 (6%).CONCLUSION: The integrase inhibitors will be effective in Kenya where HIV-1 subtype A1 is still the most predominant. However, occurring polymorphisms may warrant further investigation among drug experienced individuals on dolutegravir combination or integrase inhibitor treatment. 


Author(s):  
Diego Cecchini ◽  
◽  
Javier Sfalcin ◽  
Inés Zapiola ◽  
Alan Gómez ◽  
...  

Objective. Argentina has reported high levels of transmitted drug resistance (TDR), in HIV-infected pregnant women by population sequencing. We aimed to describe, in patients with TDR, the percentage of quasispecies harboring resistance mutations (RAMs) and mutational load (ML). Patients and Methods. Retrospective study in a cohort of 40 naïve HIV-infected pregnant women, whose pretreatment samples had been genotyped by TRUGENE (period 2008-2014). Samples were re-sequenced with Ultra-deep Sequencing and ML was calculated considering baseline HIV-1 RNA load multiplied by the frequency of quasispecies harboring RAMs. Results. TDR for NNRTIs, NRTIs and PIs was 17.5% (n=7 patients), 10% (n=4), 12.5% (n=5) respectively. Predominant NNRTI RAMs were K103N (n=4; 10%) and G190A/E/S (n=3; 7.5%). For NNRTIs, 78% of RAMs were present in >93.5% of viral population and ML was >1000 copies/mL (c/mL) for 89%, with a median (IQR) of 8330 c/ml (7738-29796). The following NRTI RAMs were described (per patient: % of quasispecies, ML): T215I (99.7%, 11014 c/ml); D67G (1.28%, 502 c/mL); M41L (79.8%, 88578 c/mL) and M184I (1.02%, 173 c/mL). Most frequent PI-RAMs were I85V, M46I, I50V and L90M (n=2, 5% each). For PIs, quasispecies with RAMs were <2.3% of viral population and ML was <350 c/mL for 77.8% of them. Conclusion. NNRTI-RAMs are predominant within the viral population, usually exceeding the threshold of 1000 c/mL, indicating potential higher risk of perinatal transmission. Conversely, PI mutations appear mostly as minority variants, with potential lower risk of transmission. Among NRTI, quasispecies harboring RAMs and ML values were variable.


2004 ◽  
Vol 78 (13) ◽  
pp. 7112-7123 ◽  
Author(s):  
Amit Kapoor ◽  
Morris Jones ◽  
R. W. Shafer ◽  
Soo-Yon Rhee ◽  
Powel Kazanjian ◽  
...  

ABSTRACT Drug-resistant viruses may be present as minority variants during early treatment failures or following discontinuation of failed antiretroviral regimens. A limitation of the traditional direct PCR population sequencing method is its inability to detect human immunodeficiency virus type 1 (HIV-1) variants present at frequencies lower than 20%. A drug resistance genotyping assay based on the isolation and DNA sequencing of minority HIV protease variants is presented here. A multiple-codon-specific heteroduplex generator probe was constructed to improve the separation of HIV protease genes varying in sequence at 12 codons associated with resistance to protease inhibitors. Using an RNA molecule as probe allowed the simple sequencing of protease variants isolated as RNA/DNA heteroduplexes with different electrophoretic mobilities. The protease gene RNA heteroduplex generator-tracking assay (RNA-HTA) was tested on plasma quasispecies from 21 HIV-1-infected persons in whom one or more protease resistance mutations emerged during therapy or following initiation of salvage regimens. In 11 of 21 cases, RNA-HTA testing of virus from the first episode of virologic failure identified protease resistance mutations not seen by population-based PCR sequencing. In 8 of these 11 cases, all of the low-frequency drug resistance mutations detected exclusively by RNA-HTA during the first episode became detectable by population-based PCR sequencing at the later time point. Distinct sets of protease mutations could be linked on different genomes in patients with high-frequency protease gene lineages. The enhanced detection of minority drug resistance variants using a sequencing-based assay may improve the efficacy of genotype-assisted salvage therapies.


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