HIV-1 integrase inhibitor resistance among treatment naïve patients in the West of Scotland

Full-Spectrum Surveillance of Pre-Treatment HIV Drug Resistance in Southeastern China

HIV drug resistance compromises the ability of anti-retroviral therapy (ART) to suppress viral replication, resulting in treatment failure. This study investigates the prevalence of pre-treatment drug resistance (PDR) in newly diagnosed individuals in a prosperous city (Wenzhou) in Southeastern China. A cross-sectional investigation was carried out among 473 newly diagnosed ART-naive HIV-1-infected individuals between January and December 2022. The protease-reverse transcriptase (PR-RT) region and integrase (IN) region of HIV-1 were amplified by two separately nested PCRs, followed by sequencing. Drug resistance mutations (DRMs) and drug resistance to nucleoside reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs) and integrase strand transfer inhibitors (INSTIs) were analyzed. The PDR prevalence was 6.5% [95% CI: 4.4-9.1] for any anti-retroviral drug, 0.9% [95% CI: 0.3-2.3] for NRTIs, 4.1% [95% CI: 2.5-6.5] for NNRTIs, 1.8% [95% CI: 0.8-3.6] for PIs and 0.5% [95% CI: 0.1-1.8] for INSTIs. According to the subtyping results of the PR-RT region, 11 different subtypes and 31 unique recombinant forms (URFs) were found. CRF07_BC was the dominant subtype (53.7%, 233/434), followed by CRF01_AE (25.3%, 110/434). V179D (1.6%) and K103N (1.4%) were the most predominant types of NNRTI DRMs. Q58E (1.2%) and M184V (0.7%) were the most frequent PI DRMs and NRTI DRMs, respectively. The INSTI-related DRMs Y143S (causes high-level resistance to RAL) and G163K (causes low-level resistance to EVG and RAL) were found in one patient each. Given the relatively high PDR prevalence of NNRTI (4.1%), non-NNRTI-based ART may be preferred in the future. It is recommended to include genotypic resistance testing before starting ART in regions where feasible.

Preliminary report of transmitted drug resistance to integrase strand chain transfer inhibitors in treatment-naïve HIV infected patients

Transmitted Resistance exists in a newly diagnosed person who has not yet started their treatment. Our objective was to obtain a profile of HIV-1 resistance to integrase inhibitors in newly diagnosed treatment-naïve patients. Fifty people newly diagnosed with HIV-1 infection who had never received antiretroviral treatment were recruited. The complete integrase gene was amplified by nested RTPCR and the sequences obtained were analyzed with the ReCall and HIVdb v9.0. The overall prevalence transmitted due to mutations with some impact on integrase strand transfer inhibitors (INSTI) activity during the study period was 8%. The major E138K mutation was detected in only 1 patient and the secondary G163R mutation was detected in the other 3. The transmitted resistance for the first generation INSTI was 8% and for the second generation it was 0%. In Chile the resistance transmitted to INSTI is low and it is in according values detect in other part of the world.

Low level of HIV-1C integrase strand transfer inhibitor resistance mutations among recently diagnosed ART-naive Ethiopians

With the widespread use of Integrase strand transfer inhibitors (INSTIs), surveillance of HIV-1 pretreatment drug resistance is critical in optimizing antiretroviral treatment efficacy. However, despite the introduction of these drugs, data concerning their resistance mutations (RMs) is still limited in Ethiopia. Thus, this study aimed to assess INSTI RMs and polymorphisms at the gene locus coding for Integrase (IN) among viral isolates from ART-naive HIV-1 infected Ethiopian population. This was a cross-sectional study involving isolation of HIV-1 from plasma of 49 newly diagnosed drug-naive HIV-1 infected individuals in Addis-Ababa during the period between June to December 2018. The IN region covering the first 263 codons of blood samples was amplified and sequenced using an in-house assay. INSTIs RMs were examined using calibrated population resistance tool version 8.0 from Stanford HIV drug resistance database while both REGA version 3 online HIV-1 subtyping tool and the jumping profile Hidden Markov Model from GOBICS were used to examine HIV-1 genetic diversity. Among the 49 study participants, 1 (1/49; 2%) harbored a major INSTIs RM (R263K). In addition, blood specimens from 14 (14/49; 28.5%) patients had accessory mutations. Among these, the M50I accessory mutation was observed in a highest frequency (13/49; 28.3%) followed by L74I (1/49; 2%), S119R (1/49; 2%), and S230N (1/49; 2%). Concerning HIV-1 subtype distribution, all the entire study subjects were detected to harbor HIV-1C strain as per the IN gene analysis. This study showed that the level of primary HIV-1 drug resistance to INSTIs is still low in Ethiopia reflecting the cumulative natural occurrence of these mutations in the absence of selective drug pressure and supports the use of INSTIs in the country. However, continues monitoring of drug resistance should be enhanced since the virus potentially develop resistance to this drug classes as time goes by.

UK guideline for the use of HIV post-exposure prophylaxis 2021

We present the updated British Association for Sexual Health and HIV (BASHH) guidelines for post-exposure prophylaxis (PEP) to HIV following sexual exposures, occupational exposures and other nonoccupational exposures in the community. This serves as an update to the 2015 BASHH guideline on PEP following sexual exposures and the 2008 Expert Advisory Group on AIDS guidelines on HIV PEP. We aim to provide evidence-based guidance on best clinical practice in the provision, monitoring and support of PEP for the prevention of HIV acquisition following sexual, occupational and other nonoccupational exposures in the community. The guideline covers when to prescribe PEP, what antiretroviral agents to use and how to manage PEP. This includes (i) evidence of PEP efficacy; (ii) evidence relating to individual-level efficacy of antiretroviral therapy to prevent the sexual transmission of HIV; (iii) data on the detectable (transmissible) prevalence of HIV in specific populations; (iv) risk of HIV transmission following different types of sexual and occupational exposure; (v) baseline risk assessment; (vi) drug regimens and dosing schedules; (vii) monitoring PEP; (viii) baseline and follow-up blood-borne virus testing; (ix) the role of PEP within broader HIV prevention strategies, for example, HIV pre-exposure prophylaxis (PrEP). The guideline also covers special scenarios such as PEP in pregnancy, breastfeeding and chronic hepatitis B virus infection, and when PEP should be considered in people using HIV PrEP. The guidelines are aimed at clinical professionals directly involved in PEP provision and other stakeholders in the field. A proforma to assist PEP consultations is included. A public consultation process was undertaken prior to finalizing the recommendations.

Prevalence of resistance mutations associated with integrase inhibitors in therapy-naive HIV-positive patients in Hungary

Widespread introduction of HIV integrase inhibitors into clinical care may result in appearance of drug resistance mutations affecting treatment outcome. The aim of our study was to monitor the resistance patterns of integrase inhibitors beside protease and reverse transcriptase inhibitors in newly diagnosed therapy-naive HIV-positive patients in Hungary between 2017 and 2019.Genotype-based resistance testing of HIV integrase, protease and reverse transcriptase was performed by amplification and Sanger population sequencing from plasma samples. Drug resistance mutations were identified by the algorithm of Stanford HIV Drug Resistance Database.Potentially transmitted, non-polymorphic integrase major mutation was detected in 1 out of 249 samples, while accessory mutations were observed in further 31 patients (12.4%). The overall prevalence of transmitted drug resistance (TDR) mutations related to protease and reverse transcriptase inhibitors was 5.8% (10/173) between the end of 2017 and 2019. Nucleoside reverse transcriptase inhibitor associated resistance mutations were the most frequent indicators of TDR (6/173; 3.5%), followed by resistance mutations associated with protease (3/173; 1.7%) and non-nucleoside reverse transcriptase inhibitors (2/173, 1.2%).The first detection of integrase major mutation and the changing patterns of other resistance mutations in Hungarian untreated HIV-positive population indicate the necessity of continuous molecular surveillance of Hungarian HIV epidemic.

Absence of Integrase Inhibitor-Associated Resistance Among Antiretroviral Therapy-Naïve HIV-1-Infected Adults in Guangdong Province, China, in 2018

Background

Antiretroviral therapy (ART) containing an integrase strand transfer inhibitor (INSTI) plus two nucleoside reverse-transcriptase inhibitors has been recommended as a first-line regimen for ART-naïve HIV-1-infected patients in the latest Chinese Guidelines for Diagnosis and Treatment of HIV/AIDS.

Objective

To determine the prevalence of INSTI-related mutations among ART-naïve HIV-1-infected adults in Guangdong, China, in 2018.

Methods

The entire integrase gene was amplified from blood plasma. Demographic and epidemiological information was collected. INSTI mutations and antiretroviral susceptibility were interpreted using the Stanford University HIV Drug Resistance Database HIVdb program.

Results

Of 927 samples, 827 integrase sequences were successfully obtained. Among them, no major resistance mutations to INSTIs were identified, and four accessory mutations, including T97A (0.12%, 1/827), A128T (0.24%, 2/827), E157Q (0.85%, 7/827), and G163R (0.24%, 2/827), were found in twelve individuals. Two patient samples contained the G163R mutation conferring low-level resistance to elvitegravir and raltegravir.

Conclusion

The overall prevalence of INSTI mutations remains low. Drug resistance mutation testing for the detection of INSTI drug resistance mutations in HIV treatment-naïve patients should be considered due to the circulation of polymorphisms contributing to INSTI resistance and the expected increasing use of this class of drugs.

Development of a new comprehensive HIV-1 genotypic drug resistance assay for all commercially available reverse transcriptase, protease and integrase inhibitors in patients infected with group M HIV-1 strains

Comprehensive PCR assays for the genotypic drug resistance analysis of all HIV-1 antiretroviral agents (reverse transcriptase, protease and integrase inhibitors) are increasingly in demand due to introduction of integrase inhibitors in the first line regimens and the increasing presence of non-B HIV-1 clades around the world. This study focused on the development and evaluation of a new PCR-based assay for the amplification and sequencing of the entire HIV-1 pol region of major circulating group M HIV-1 strains in Europe for genotypic drug resistance analysis. The comprehensive touchdown PCR assay developed in this study utilized HIV-1 RNA extracted from the plasma of blood samples of consenting HIV-1 infected patients in Cyprus, collected from 2017 to 2019. The HIV-1 pol region was amplified by touchdown PCR for both the primary RT-PCR and the secondary PCR steps. Successful PCR amplicons were determined by population DNA sequencing, using the Sanger method and the genotypic drug resistance analysis was performed with the Stanford University HIV Drug Resistance Database Program. The newly developed assay successfully amplified the entire HIV-1 pol region (2844 nucleotides long) of 141 out of 144 samples of group M HIV-1 subtypes and recombinant strains of the Cyprus HIV-1 Transmission Cohort Study (CHICS) isolated from 2017 to 2019 and genotypic analyses were conducted for all currently available HIV-1 reverse transcriptase, protease and integrase inhibitors. The drug resistance, epidemiological and demographic data of these study subjects will be expanded upon in the CHICS (L.G. Kostrikis et al., manuscript in preparation for publication). The newly developed HIV-1 genotypic drug resistance assay would benefit clinical settings, and research focusing on the world-wide spread of HIV-1 drug-resistant strains, especially in geographic regions characterized by polyphyletic HIV-1 infections.

HIV-1 integrase drug-resistance mutations in Iranian treatment-experienced HIV-1-infected patients

The latest class of antiretrovirals (ARVs), including integrase strand transfer inhibitors (INSTIs), has been demonstrated to be effective for antiretroviral therapy (ART). Despite all the distinguishing characteristics of these drugs, including a high genetic barrier to resistance and lower toxicity than other ARVs, unfortunately, INSTI drug resistance mutations (DRMs) have occasionally been observed. The aim of this study was to investigate the presence of DRMs associated with INSTIs among treatment-experienced HIV-1-infected patients. From June 2012 to December 2018, a total of 655 treatment-experienced HIV-1-infected patients enrolled in this cross-sectional survey. Following amplification and sequencing of the HIV-1 integrase region of the pol gene, DRM and phylogenetic analysis were successfully carried out on the plasma samples of patients who had a viral load over 1,000 IU/ml after at least 6 months of ART. Out of the 655 patients evaluated, 62 (9.5%) had a viral load higher than 1,000 IU/ml after at least 6 months of ART. Phylogenetic analysis showed that all of the 62 HIV-1 patients experiencing treatment failure were infected with CRF35_AD, and one of these patients (1.6%) was infected with HIV-1 variants with DRMs. The DRMs that were identified belonged to the INSTI class, including E138K, G140A, S147G, and Q148R. This survey shows that DRMs belonging to the INSTI class were detected in an Iranian HIV patient who has experienced treatment failure. Therefore, regarding the presence of DRMs to INSTIs in ART-experienced patients, it seems better to perform drug resistance mutation testing in HIV patients experiencing treatment failure before changing the ART regimen and prescribing this class of medication.

Evaluation of HIV-1 integrase resistance emergence and evolution in patients treated with integrase inhibitors

OBJECTIVES

This study evaluated the emergence of mutations associated with integrase strand transfer inhibitors (INSTI) resistance (INSTI-RMs) and the integrase evolution in human immunodeficiency virus type 1 (HIV-1) infected patients treated with this drug class.

METHODS

The emergence of INSTI-RMs and integrase evolution (estimated as genetic distance between integrase sequences under INSTI treatment and before INSTI treatment) were evaluated in 107 INSTI-naïve patients (19 drug-naïve and 88 drug-experienced) with two plasma genotypic resistance tests: one before INSTI treatment and one under INSTI treatment. A logistic regression analysis was performed to evaluate factors associated with the integrase evolution under INSTI treatment.

RESULTS

The patients were mainly infected by B subtype (72.0%). Eighty-seven patients were treated with raltegravir, 13 with dolutegravir and seven with elvitegravir. Before INSTI treatment one patient harboured the major INSTI-RM R263K and three patients the accessory INSTI-RMs T97A. Under INSTI treatment the emergence of ≥1 INSTI-RM was found in 39 (36.4%) patients. The major INSTI-RMs that more frequently emerged were: N155H (17.8%), G140S (8.4%), Y143R (7.5%), Q148H (6.5%), and Y143C (4.7%). Concerning integrase evolution, a higher genetic distance was found in patients with ≥1 INSTI-RM compared with those without emergence of resistance (0.024 [0.012-0.036] vs. 0.015 [0.009-0.024], P=0.018). This higher integrase evolution was significantly associated with a longer duration of HIV-1 infection, a higher number of past regimens and non-B subtypes.

CONCLUSIONS

These findings confirm that major INSTI-RMs very rarely occur in INSTI-naïve patients. Under INSTI treatment, selection of drug-resistance follows the typical drug-resistance pathways; a higher evolution characterises integrase sequences developing drug-resistance compared with those without any resistance.

Integrase Strand Transfer Inhibitor Resistance Mutations in Antiretroviral Therapy-Naive and Treatment-Experienced HIV Patients in South Korea

Updated guidelines for the treatment of antiretroviral therapy (ART)-negative patients with HIV recommend integrase strand transfer inhibitor (INSTI)-based regimens. HIV patients are tested for resistance to antiretrovirals, and the reported prevalence of transmitted INSTI resistance remains rare worldwide. However, no data related to INSTI resistance in Korean HIV patients have been reported. We aimed to determine the prevalence of INSTI resistance-related mutations in South Korea. We subjected both ART-naive (n = 58) and ART-experienced Korean HIV patients (n = 41) to genotypic resistance analysis and determined a prevalence of INSTI major resistance mutations of 3.4% (n = 2) among ART-naive patients and 22.0% (n = 9) among ART-experienced patients. In the former group, both major INSTI resistance cases involved the nonpolymorphic E92Q mutation in the integrase strand. Our findings suggest that INSTI resistance testing should be included in the standard resistance screening protocols for Korean HIV patients.