Performance comparison of an in-house integrase genotyping assay versus the ViroSeq™ Integra48, and study of HIV-1 integrase polymorphisms in Hong Kong

Long-Read Sequencing with Hierarchical Clustering for Antiretroviral Resistance Profiling of Mixed Human Immunodeficiency Virus Quasispecies

BACKGROUND

HIV infections often develop drug resistance mutations (DRMs), which can increase the risk of virological failure. However, it has been difficult to determine if minor mutations occur in the same genome or in different virions using Sanger sequencing and short-read sequencing methods. Oxford Nanopore Technologies (ONT) sequencing may improve antiretroviral resistance profiling by allowing for long-read clustering.

METHODS

A new ONT sequencing-based method for profiling DRMs in HIV quasispecies was developed and validated. The method used hierarchical clustering of long amplicons that cover regions associated with different types of antiretroviral drugs. A gradient series of an HIV plasmid and 2 plasma samples was prepared to validate the clustering performance. The ONT results were compared to those obtained with Sanger sequencing and Illumina sequencing in 77 HIV-positive plasma samples to evaluate the diagnostic performance.

RESULTS

In the validation study, the abundance of detected quasispecies was concordant with the predicted result with the R2 of > 0.99. During the diagnostic evaluation, 59/77 samples were successfully sequenced for DRMs. Among 18 failed samples, 17 were below the limit of detection of 303.9 copies/μL. Based on the receiver operating characteristic analysis, the ONT workflow achieved an F1 score of 0.96 with a cutoff of 0.4 variant allele frequency. Four cases were found to have quasispecies with DRMs, in which 2 harbored quasispecies with more than one class of DRMs. Treatment modifications were recommended for these cases.

CONCLUSIONS

Long-read sequencing coupled with hierarchical clustering could differentiate the quasispecies resistance profiles in HIV-infected samples, providing a clearer picture for medical care.

HIV-1 Drug Resistance Genotyping in Resource Limited Settings: Current and Future Perspectives in Sequencing Technologies

Affordable, sensitive, and scalable technologies are needed for monitoring antiretroviral treatment (ART) success with the goal of eradicating HIV-1 infection. This review discusses use of Sanger sequencing and next generation sequencing (NGS) methods for HIV-1 drug resistance (HIVDR) genotyping, focusing on their use in resource limited settings (RLS). Sanger sequencing remains the gold-standard method for detecting HIVDR mutations of clinical relevance but is mainly limited by high sequencing costs and low-throughput. NGS is becoming a more common sequencing method, with the ability to detect low-abundance drug-resistant variants and reduce per sample costs through sample pooling and massive parallel sequencing. However, use of NGS in RLS is mainly limited by infrastructure costs. Given these shortcomings, our review discusses sequencing technologies for HIVDR genotyping, focusing on common in-house and commercial assays, challenges with Sanger sequencing in keeping up with changes in HIV-1 treatment programs, as well as challenges with NGS that limit its implementation in RLS and in clinical diagnostics. We further discuss knowledge gaps and offer recommendations on how to overcome existing barriers for implementing HIVDR genotyping in RLS, to make informed clinical decisions that improve quality of life for people living with HIV.

Genotypic Methods for HIV Drug Resistance Monitoring: The Opportunities and Challenges Faced by China

AIDS is a globalized infectious disease. In 2014, UNAIDS launched a global project of "90-90-90" to end the HIV epidemic by 2030. The second and third 90 require 90% of HIV-1 infected individuals receiving antiretroviral therapy (ART) and durable virological suppression. However, wide use of ART will greatly increase the emergence and spreading of HIV drug resistance and current HIV drug resistance test (DRT) assays in China are seriously lagging behind, hindering to achieve virological suppression. Therefore, recommending an appropriate HIV DRT method is critical for HIV routine surveillance and prevention in China. In this review, we summarized the current existing HIV drug resistance genotypic testing methods around the world and discussed the advantages and disadvantages of these methods.

Comparison of an in-house 'home-brew' and commercial ViroSeq integrase genotyping assays on HIV-1 subtype C samples

Background

Roll-out of Integrase Strand Transfer Inhibitors (INSTIs) such as dolutegravir for HIV combination antiretroviral therapy (cART) in sub-Saharan Africa necessitates the development of affordable HIV drug resistance (HIVDR) assays targeting the Integrase gene. We optimised and evaluated an in-house integrase HIV-1 drug resistance assay (IH-Int) and compared it to a commercially available assay, ViroSeq^™ Integrase Genotyping kit (VS-Int) amongst HIV-1 clade C infected individuals.

Methods

We used 54 plasma samples from treatment naïve participants and one plasma sample from a patient failing INSTI based cART. Specimens were genotyped using both the VS-Int and IH-Int assays. Stanford HIV drug resistance database were used for integrase resistance interpretation. We compared the major and minor resistance mutations, pairwise nucleotide and amino-acid identity, costs and assay time.

Results

Among 55 specimens tested with IH-Int, 53 (96.4%) successfully amplified compared to 45/55 (81.8%) for the VS-Int assay. The mean nucleotide and amino acid similarity from 33 paired sequences was 99.8% (SD ± 0.30) and 99.8% (SD ± 0.39) for the IH-Int and VS-Int assay respectively. The reagent cost/sample were 32 USD and 147 USD for IH-Int and VS-Int assay, respectively. All sequenced samples were confirmed as HIV-1 subtype C.

Conclusions

The IH-Int assay had a high amplification success rate and high concordance with the commercial assay. It is significantly cheaper compared to the commercial assay. Our assay has the needed specifications for routine monitoring of participants on Dolutegravir based regimens in Botswana.

Transmitted drug resistance of HIV-1 strains among individuals attending voluntary counselling and testing in Taiwan

BACKGROUND

Genotypic drug resistance testing for HIV-1 has been integrated into voluntary counselling and testing (VCT) programmes to investigate the trends of transmitted drug resistance (TDR), including integrase mutations, among individuals with recent or chronic HIV infections in Taiwan.

METHODS

Between 2006 and 2014, 745 of 21 886 subjects (3.4%) tested HIV positive in the VCT service. The BED assay was used to identify recent HIV infections. Genotypic resistance mutations were interpreted using the WHO 2009 list. Integrase resistance mutations were analysed using the Stanford HIV Drug Resistance Database.

RESULTS

Three-hundred-and-sixty (48.3%) patients were recently infected with HIV-1. Of 440 patients linked to HIV care with analysable reverse transcriptase and protease genes, 49 (11.1%) were infected with HIV-1 harbouring at least one resistance-associated mutation (RAM). The prevalence of TDR to NRTIs, NNRTIs and PIs was 4.1%, 6.4% and 2.3%, respectively. TDR prevalence did not change significantly during the study period. CD4 counts ≤500 cells/mm(3) and hepatitis B surface antigen positivity were independent factors associated with acquiring drug-resistant HIV. The prevalence of integrase mutations was 3.2%. Among the seven major integrase mutations (T66I, E92Q, G140S, Y143C/H/R, S147G, Q148H/K/R and N155H), only one strain harbouring the Q148R mutation was detected. We found no statistically significant difference between patients with chronic infection and those with recent infection in the prevalence of drug-resistant mutations to any of the four classes of antiretroviral agents.

CONCLUSIONS

The prevalence of TDR of HIV-1 strains to available antiretroviral agents is moderately high, but transmission of HIV-1 with drug-resistant mutations remains stable in Taiwan.

HIV-1 integrase genotyping is reliable and reproducible for routine clinical detection of integrase resistance mutations even in patients with low-level viraemia

OBJECTIVES

Integrase drug resistance monitoring deserves attention because of the increasing number of patients being treated with integrase strand-transfer inhibitors. Therefore, we evaluated the integrase genotyping success rate at low-level viraemia (LLV, 51-1000 copies/mL) and resistance in raltegravir-failing patients.

METHODS

An integrase genotypic resistance test (GRT) was performed on 1734 HIV-1 samples collected during 2006-13. Genotyping success rate was determined according to the following viraemia levels: 51-500, 501-1000, 1001-10 000, 10 001-100 000 and >100 000 copies/mL. The reproducibility of integrase GRT was evaluated in 41 plasma samples processed in duplicate in two reference centres. The relationship between LLV and resistance prevalence was evaluated in a subset of 120 raltegravir-failing patients.

RESULTS

Overall, the integrase genotyping success rate was 95.7%. For viraemia levels 51-500 and 501-1000 copies/mL, the rate of success was 82.1% and 94.0%, respectively. GRT was reproducible, producing sequences with a high similarity and an equal resistance profile regardless of the sequencing centre or viraemia level. Resistance was detected both at LLV and at viraemia >1000 copies/mL (51-500 copies/mL = 18.2%; 501-1000 = 37.5%; 1001-10 000 = 53.7%; 10 001-100 000 = 30.0%; and >100 000 = 30.8%). At viraemia ≤500 copies/mL, Q148H/K/R and N155H had the same prevalence (9.1%), while the Y143C/H/R was completely absent. At early genotyping (within 3 months of raltegravir treatment), Q148H/K/R and N155H mutations were detected regardless of the viraemia level, while Y143C/H/R was observed only in samples with viraemia >1000 copies/mL.

CONCLUSIONS

Our findings prove the reliability of HIV-1 integrase genotyping and reinforce the concept that this assay may be useful in the management of failures even at LLV.