The WHO has recommended that antiretroviral therapy be provided to all HIV patients to reduce future HIV transmission rates. However, few studies have examined this public health strategy at the population level in a real-world setting.In this longitudinal genetic-network study in Guangxi, China, the baseline and follow-up data were collected from HIV patients in 2014 and newly diagnosed HIV patients from 2015 to 2018, respectively. The prevention efficacy was used to estimate the effect of treatment-as-prevention in reducing HIV secondary transmission.Among 804 newly diagnosed HIV patients during 2015-2018, 399 (49.6%) of them genetically linked to HIV patients at baseline during 2014-2017. The overall proportion of genetic linkage between newly diagnosed HIV patients during 2015-2018 with untreated and treated HIV patients at baseline during 2014-2017 was 6.2 and 2.9%, respectively. The prevention efficacy in HIV transmission for treated HIV patients was 53.6% [95% confidence interval (95% CI): 42.1-65.1]. Subgroup analyses indicated an 80.3% (95% CI: 74.8-85.8) reduction in HIV transmission among HIV patients who were treated for 4 years or more and had viral loads less than 50 copies/ml. There was no significant reduction in HIV transmission among treated HIV patients who dropped out or who had missing viral load measures.Our study results support the feasibility of treating all HIV patients for future reductions in HIV transmission at the population level in real-world settings. Comprehensive intervention prevention programmes are urgently needed.Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.

The hypothesis that quiescent CD4+ T lymphocytes carrying proviral DNA provide a reservoir for human immunodeficiency virus-type 1 (HIV-1) in patients on highly active antiretroviral therapy (HAART) was examined. In a study of 22 patients successfully treated with HAART for up to 30 months, replication-competent virus was routinely recovered from resting CD4+ T lymphocytes. The frequency of resting CD4+ T cells harboring latent HIV-1 was low, 0.2 to 16.4 per 10(6) cells, and, in cross-sectional analysis, did not decrease with increasing time on therapy. The recovered viruses generally did not show mutations associated with resistance to the relevant antiretroviral drugs. This reservoir of nonevolving latent virus in resting CD4+ T cells should be considered in deciding whether to terminate treatment in patients who respond to HAART.

Combination antiretroviral therapy with protease inhibitors has transformed HIV infection from a terminal condition into one that is manageable. However, the complexity of regimens makes adherence to therapy difficult.To assess the effects of different levels of adherence to therapy on virologic, immunologic, and clinical outcome; to determine modifiable conditions associated with suboptimal adherence; and to determine how well clinicians predict patient adherence.Prospective, observational study.HIV clinics in a Veterans Affairs medical center and a university medical center.99 HIV-infected patients who were prescribed a protease inhibitor and who neither used a medication organizer nor received their medications in an observed setting (such as a jail or nursing home).Adherence was measured by using a microelectronic monitoring system. The adherence rate was calculated as the number of doses taken divided by the number prescribed. Patients were followed for a median of 6 months (range, 3 to 15 months).During the study period, 45,397 doses of protease inhibitor were monitored in 81 evaluable patients. Adherence was significantly associated with successful virologic outcome (P < 0.001) and increase in CD4 lymphocyte count (P = 0.006). Virologic failure was documented in 22% of patients with adherence of 95% or greater, 61% of those with 80% to 94.9% adherence, and 80% of those with less than 80% adherence. Patients with adherence of 95% or greater had fewer days in the hospital (2.6 days per 1000 days of follow-up) than those with less than 95% adherence (12.9 days per 1000 days of follow-up; P = 0.001). No opportunistic infections or deaths occurred in patients with 95% or greater adherence. Active psychiatric illness was an independent risk factor for adherence less than 95% (P = 0.04). Physicians predicted adherence incorrectly for 41% of patients, and clinic nurses predicted it incorrectly for 30% of patients.Adherence to protease inhibitor therapy of 95% or greater optimized virologic outcome for patients with HIV infection. Diagnosis and treatment of psychiatric illness should be further investigated as a means to improve adherence to therapy.

Attrition due to loss to follow-up or termination of antiretroviral therapy (ART) among HIV-infected patients in care may increase the risk of emergence and transmission of drug resistance (TDR), diminish benefit of treatment, and increase morbidity and mortality. Understanding the impact of attrition on the epidemic is essential to provide interventions for improving retention in care.

Understanding the origin of HIV variants during viral rebound may provide insight into the composition of the HIV reservoir and has implications for the design of curative interventions. HIV single-genome sequences were obtained from 10 AIDS Clinical Trials Group participants who underwent analytic antiretroviral therapy (ART) interruption (ATI). Rebounding variants were compared with those in pre-ART plasma in all 10 participants and with on-ART peripheral blood mononuclear cell (PBMC)-associated DNA and RNA (CA-RNA) in 7/10 participants. The highest viral diversities were found in the DNA and CA-RNA populations. In 3 of 7 participants, we detected multiple, identical DNA and CA-RNA sequences during suppression on ART that exactly matched plasma HIV sequences. Hypermutated DNA and CA-RNA were detected in four participants, contributing to diversities in these compartments that were higher than in the pre-ART and post-ATI plasma. Shifts in the viral rebound populations could be detected in some participants over the 2- to 3-month observation period. These findings suggest that a source of initial rebound viremia could be populations of infected cells that clonally expanded prior to and/or during ART, some of which were already expressing HIV RNA before treatment was interrupted. These clonally expanding populations of HIV-infected cells may represent an important target for strategies aimed at achieving reservoir reduction and sustained virologic remission.

The World Health Organization (WHO) HIV drug resistance (HIVDR) threshold survey method was developed for surveillance of transmitted HIVDR in resource-limited countries. The method is being implemented with minimal resources as a routine public health activity to produce comparable results in multiple countries and areas within countries. Transmitted drug resistant HIV strains will be seen first in cities or health districts where antiretroviral treatment (ART) has been widely available for years. WHO recommends countries begin surveillance in these areas.

目的：了解中国未接受抗逆转录病毒治疗的人类免疫缺陷病毒/获得性免疫缺陷综合征（human immunodeficiency virus infection and acquired immune deficiency syndrome，HIV/AIDS）人群HIV原发耐药水平。方法：检索5个数据库：《中国生物医学文献数据库》(Chinese BioMedical Literature Database, CBM)、《中国期刊全文数据库》(Chinese Journal Full-text Database, CNKI)、《中文科技期刊数据库-维普》(Chinese Science-Technology Journal Database, VIP)、万方数据知识服务平台及PubMed数据库，提取HIV耐药数据，使用随机效应模型对数据进行合并，对采样时间、采样地点、人群特征（平均年龄及感染状态）、样本量进行亚组分析。结果：共纳入76篇文献（中文46篇，英文30篇），中国未接受抗病毒治疗的HIV/AIDS人群HIV原发整体耐药率、非核苷类反转录酶抑制剂（non-nucleoside reverse transcriptase inhibitor，NNRTI）耐药率、核苷类反转录酶抑制剂（nucleoside reverse transcriptase inhibitor，NRTI）耐药率、蛋白酶抑制剂（protease inhibitor，PI）耐药率分别为4.7% (95%CI: 4.0%~5.4%)、2.3% (95%CI: 1.8%~2.8%)、1.8% (95%CI: 1.3%~2.3%)、1.4% (95%CI: 1.1%~1.8%)。上述4类耐药率均是2007年之前高于之后，且都存在显著地区差异（P<0.05），其中，中南及西南地区整体耐药率均高于5%。平均年龄、感染状态亚组中，组间差异较为复杂，其中小于25岁及新发、新确认组其整体耐药率低于25岁以上及非新发、新确认组。样本量<100的亚组，各耐药率均高于样本量&ge;100的亚组，且差异都有统计学意义（P<0.05）。结论：中国HIV/AIDS人群HIV病毒原发总耐药率为4.7%，仍处于低流行状态，但已接近WHO提出的5%中度耐药警戒线，中南及西南地区整体耐药率已经超过该警戒线，应进一步加强监测。

To investigate the prevalence and temporal trend of transmitted drug resistance (TDR), a nationwide cross-sectional survey was conducted among 5627 ART naive newly diagnosed HIV-infected individuals in 2015 in China. Totally 4704 partial pol sequences were obtained. Among them, the most common HIV-1 circulating recombinant form (CRF) or subtype was CRF01_AE (39.0%), followed by CRF07_BC (35.6%), CRF08_BC (8.9%), and subtype B (5.5%). TDR mutations were found in 3.6% of the cases, with 1.1% harboring TDR to protease inhibitors (PIs), 1.3% having TDR to nucleoside reverse transcriptase inhibitors (NRTIs), and 1.6% to non-nucleoside reverse transcriptase inhibitors (NNRTIs). No significant difference was found in the prevalence of TDR, as compared with the results of another nationwide survey performed among ART naive HIV-infected people in between 2004 and 2005, except in the 16-25 year-old group. In addition, four drug-resistant transmission clusters were identified in phylogenetic trees, accounting for 6.2% (9/145) of the individuals with TDR. Although the rate of TDR remained relatively low in the past 10 years in China, surveillance is still needed to monitor the trend of TDR and to optimize the first-line regimens.

After the scale-up of antiretroviral therapy (ART) for HIV infected people, increasing numbers of patients have pretreatment drug resistance (PDR). In this study, the prevalence of PDR was evaluated in adults initiating antiretroviral therapy in China.

Transmitted drug resistance (TDR) may compromise the effect of antiretroviral therapy (ART), highlighting the necessity for continuous monitoring.

New evidence has emerged regarding when to commence antiretroviral therapy (ART), optimal treatment regimens, management of HIV co-infection with opportunistic infections, and management of ART failure. The 2014 guidelines were developed by the collaborations of the Department of Disease Control, Ministry of Public Health (MOPH) and the Thai AIDS Society (TAS). One of the major changes in the guidelines included recommending to initiating ART irrespective of CD4 cell count. However, it is with an emphasis that commencing HAART at CD4 cell count above 500 cell/mm(3) is for public health, in term of preventing HIV transmission and personal benefit. In tuberculosis co-infected patients with CD4 cell counts <= 50 cells/mm(3) or with CD4 cell counts >50 cells/mm(3) who have severe clinical disease, ART should be initiated within 2 weeks of starting tuberculosis treatment. The preferred initial ART regimen in treatment naive patients is efavirenz combined with tenofovir and emtricitabine or lamivudine. Plasma HIV viral load assessment should be done twice a year until achieving undetectable results; and will then be monitored once a year. CD4 cell count should be monitored every 6 months until CD4 cell count >= 350 cells/mm(3) and with plasma HIV viral load <50 copies/mL; then it should be monitored once a year afterward. HIV drug resistance genotypic test is indicated when plasma HIV viral load >1,000 copies/mL while on ART. Ritonavir-boosted lopinavir or atazanavir in combination with optimized two nucleoside-analogue reverse transcriptase inhibitors is recommended after initial ART regimen failure. Long-term ART-related safety monitoring has also been included in the guidelines.

Almost fifteen years ago, the first non-nucleoside reverse transcriptase (RT) inhibitor (NNRTI) lead compounds have been discovered. Nowadays, three NNRTIs are approved for treatment of HIV-1-infected individuals and several others are subject of (advanced) clinical trials. Although the NNRTIs target HIV-1 RT, they are clearly different from the nucleoside RT inhibitors (NRTIs). They are highly selective for HIV-1 and do not inhibit HIV-2 or any other (retro)virus. They target HIV-1 RT by a direct interaction without the need to be metabolised by cellular enzymes, and they interact at a site on the HIV-1 RT that is near to, but distant from, the substrate-binding site. The majority of NNRTIs share common conformational properties and structural features that let them fit in a hydrophobic pocket at the HIV-1 RT, which is nowadays well-characterized. A wide variety of crystal structures of RT complexed with NNRTIs have been obtained. They provide detailed insights in the molecular interaction of the NNRTIs with the amino acids lining the pocket in HIV-1 RT. Due to their unprecedented specificity, the NNRTIs are relatively non-toxic in cell culture, and the most potent compounds reach selectivity indices that exceed 100,000 or more. However, inherent to their high specificity, the NNRTIs easily select for mutant virus strains with several degrees of drug resistance. The first-generation NNRTIs such as nevirapine and delavirdine easily loose their inhibitory potential against mutant virus strains that contain single amino acid mutations in their RT. The second-generation NNRTIs such as efavirenz, capravirine and etravirine [corrected] usually require two or more mutations in the HIV-1 RT before significantly decreasing their antiviral potency. Evidently, it requires a markedly longer time period to obtain significant resistance against second-generation NNRTIs. The resistance spectrum of NNRTIs is entirely different from the NRTI resistance spectrum, and, as a rule, NRTI-resistant mutant virus strains keep full sensitivity to the inhibitory effects of NNRTIs, and vice versa NNRTI-resistant and mutant virus strains keep full sensitivity to the inhibitory effects of NRTIs. NNRTIs have proven beneficial when included in drug combination (triple or quadruple) therapy, preferably in the presence of protease inhibitors and NRTIs.

Presence of low-frequency, or minority, human immunodeficiency virus type 1 (HIV-1) drug resistance mutations may adversely affect response to antiretroviral treatment (ART), but evidence regarding the effects of such mutations on the effectiveness of first-line ART is conflicting.To evaluate the association of preexisting drug-resistant HIV-1 minority variants with risk of first-line nonnucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral virologic failure.Systematic review of published and unpublished studies in PubMed (1966 through December 2010), EMBASE (1974 through December 2010), conference abstracts, and article references. Authors of all studies were contacted for detailed laboratory, ART, and adherence data.Studies involving ART-naive participants initiating NNRTI-based regimens were included. Participants were included if all drugs in their ART regimen were fully active by standard HIV drug resistance testing. Cox proportional hazard models using pooled patient-level data were used to estimate the risk of virologic failure based on a Prentice weighted case-cohort analysis stratified by study.Individual data from 10 studies and 985 participants were available for the primary analysis. Low-frequency drug resistance mutations were detected in 187 participants, including 117 of 808 patients in the cohort studies. Low-frequency HIV-1 drug resistance mutations were associated with an increased risk of virologic failure (hazard ratio (HR], 2.3 [95% confidence interval {CI}, 1.7-3.3]; P <.001) after controlling for medication adherence, race/ethnicity, baseline CD4 cell count, and plasma HIV-1 RNA levels. Increased risk of virologic failure was most strongly associated with minority variants resistant to NNRTIs (HR, 2.6 [95% CI, 1.9-3.5]; P <.001). Among participants from the cohort studies, 35% of those with detectable minority variants experienced virologic failure compared with 15% of those without minority variants. The presence of minority variants was associated with 2.5 to 3 times the risk of virologic failure at either 95% or greater or less than 95% overall medication adherence. A dose-dependent increased risk of virologic failure was found in participants with a higher proportion or quantity of drug-resistant variants.In a pooled analysis, low-frequency HIV-1 drug resistance mutations, particularly involving NNRTI resistance, were significantly associated with a dose-dependent increased risk of virologic failure with first-line ART.

The effect of transmitted drug resistance (TDR) on first-line combination antiretroviral therapy (cART) for HIV-1 needs further study to inform choice of optimum drug regimens. We investigated the effect of TDR on outcome in the first year of cART within a large European collaboration.HIV-infected patients of any age were included if they started cART (at least three antiretroviral drugs) for the first time after Jan 1, 1998, and were antiretroviral naive and had at least one sample for a genotypic test taken before the start of cART. We used the WHO drug resistance list and the Stanford algorithm to classify patients into three resistance categories: no TDR, at least one mutation and fully-active cART, or at least one mutation and resistant to at least one prescribed drug. Virological failure was defined as time to the first of two consecutive viral load measurements over 500 copies per mL after 6 months of therapy.Of 10,056 patients from 25 cohorts, 9102 (90·5%) had HIV without TDR, 475 (4·7%) had at least one mutation but received fully-active cART, and 479 (4·8%) had at least one mutation and resistance to at least one drug. Cumulative Kaplan-Meier estimates for virological failure at 12 months were 4·2% (95% CI 3·8-4·7) for patients in the no TDR group, 4·7% (2·9-7·5) for those in the TDR and fully-active cART group, and 15·1% (11·9-19·0) for those in the TDR and resistant group (log-rank p<0·0001). The hazard ratio for the difference in virological failure between patients with TDR and resistance to at least one drug and those without TDR was 3·13 (95% CI 2·33-4·20, p<0·0001). The hazard ratio for the difference between patients with TDR receiving fully-active cART and patients without TDR was 1·47 (95% CI 0·19-2·38, p=0·12). In stratified analysis, the hazard ratio for the risk of virological failure in patients with TDR who received fully-active cART that included a non-nucleoside reverse transcriptase inhibitor (NNRTI) compared with those without TDR was 2·0 (95% CI 0·9-4·7, p=0·093).These findings confirm present treatment guidelines for HIV, which state that the initial treatment choice should be based on resistance testing in treatment-naive patients.European Community's Seventh Framework Programme FP7/2007-2013 and Gilead.Copyright © 2011 Elsevier Ltd. All rights reserved.

Increased access to antiretroviral therapy (ART) has resulted in rising levels of pretreatment human immunodeficiency virus drug resistance (PDR). This is the first systematic review and meta-analysis to assess the impact of PDR on treatment outcomes among people initiating nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART, including the combination of efavirenz (EFV), tenofovir (TDF), and lamivudine or emtricitabine (XTC).We systematically reviewed studies and conference proceedings comparing treatment outcomes in populations initiating NNRTI-based ART with and without PDR. We conducted subgroup analyses by regimen: (1) NNRTIs + 2 nucleoside reverse transcriptase inhibitors (NRTIs), (2) EFV + 2 NRTIs, or (3) EFV/TDF/XTC; by population (children vs adults); and by definition of resistance (PDR vs NNRTI PDR).Among 6197 studies screened, 32 were analyzed (31 441 patients). We found that individuals with PDR initiating NNRTIs across all the subgroups had increased risk of virological failure compared to those without PDR. Risk of acquisition of new resistance mutations and ART switch was also higher in people with PDR.This review shows poorer treatment outcomes in the presence of PDR, supporting the World Health Organization's recommendation to avoid using NNRTIs in countries where levels of PDR are high.© World Health Organization, 2020. All rights reserved. The World Health Organization has granted the Publisher permission for the reproduction of this article.

Pretreatment drug resistance (PDR) can limit the effectiveness of HIV antiretroviral therapy (ART). The aim of this study was to assess the prevalence of PDR among HIV-positive individuals that initiated antiretroviral therapy in 2014-2020 in southwestern China.Consecutive cross-sectional surveys were conducted in Qinzhou, Guangxi. We obtained blood samples from individuals who were newly diagnosed with HIV in 2014-2020. PDR and genetic networks analyses were performed by HIV-1 pol sequences using the Stanford HIV-database algorithm and HIV-TRACE, respectively. Univariate and multivariate logistic regression models were used to explore the potential factors associated with PDR.In total, 3236 eligible HIV-positive individuals were included. The overall prevalence of PDR was 6.0% (194/3236). The PDR frequency to NNRTI (3.3%) was much higher than that of NRTI (1.7%, p < 0.001) and PI (1.2%, p < 0.001). A multivariate logistic regression analysis revealed that PDR was significantly higher among individuals aged 18-29 (adjusted odds ratio (aOR): 1.79, 95% CI 1.28-2.50) or 30-49 (aOR: 2.82, 95% CI 1.73-4.82), and harboring CRF08_BC (aOR: 3.23, 95% CI 1.58-6.59). A total of 1429 (43.8%) sequences were linked forming transmission clusters ranging in size from 2 to 119 individuals. Twenty-two individuals in 10 clusters had the same drug resistant mutations (DRMs), mostly to NNRTIs (50%, 5/10).The overall prevalence of PDR was medium, numerous cases of the same DRMs among genetically linked individuals in networks further illustrated the importance of surveillance studies for mitigating PDR.© 2021. The Author(s).

Pretreatment drug resistance (PDR) could occur in antiretroviral treatment (ART) naïve individuals, those previously exposed to ART, or individuals re-initiating ARV after a long period of interruption. Few studies have shown its association with virological outcomes, although inconsistent. The objective of this review was to provide a synthesis of the association between PDR and virological outcomes (virological failure or suppression).

Genetic variability and liability to develop drug-resistant mutations are the main characteristics of HIV-1, which can not only increase the risk of antiretroviral treatment (ART) failure, but also can lead to the spread of resistant strains. We aim to investigate the distribution of HIV-1 genotypes and prevalence of pretreatment drug resistance (PDR) in ART-naïve HIV-1 infected patients in Shanghai China.A cross-sectional study was performed among the newly diagnosed ART-naive HIV-1 infected patients during the period from January 2017 to November 2017 in Shanghai Public Health Clinical Center. The target fragment of 1316 bp in the pol gene spanning the reverse transcriptase and protease regions was amplified using a nested polymerase chain reaction. HIV-1 genotypes were determined by phylogenetic analysis, and PDR associated mutations were determined according to Stanford University HIV Drug Resistance Database (http://hivdb.stanford.edu/).We successfully amplified pol gene sequences from blood samples of 317 patients, of whom 95.3% were male, and 68.8% were men who have sex with men. The median age was 33 years; and the median CD4 count was 275 cells/μL. The predominant HIV-1 genotype was circulating recombinant form (CRF) 01_AE (53.0%, 168/317), followed by CRF07_BC (29.7%, 94/317), B (7.6%, 24/317), CRF08_BC (1.9%, 6/317), CRF55_01B (1.9%, 6/317), CRF 59_01B (0.9%, 3/317). In addition, 5% (16/317) HIV-1 strains were identified as other subtypes or CRFs/URFs (unique recombinant forms). The overall prevalence of PDR was 17.4% (55/317). PDR frequency to non-nucleoside reverse transcriptase inhibitor (NNRTI, 16.4%) was much higher than that to nucleoside reverse transcriptase inhibitor (NRTI, 4.7%) and protease inhibitor (PI, 0.6%). The most common HIV-1 mutation pattern for NNRTI and NRTI were V179D/E (10.1%, 32/317) and M184 V (2.8%, 9/317), respectively. About half (49.1%, 27/55) of the HIV-1 strains with mutation presented as potential low-level resistant to NNRTI attributed to V179D/E.The distribution of HIV-1 genotypes in Shanghai China is diverse and complex. The high prevalence of PDR highlights the significance of baseline HIV-1 drug resistance testing. Non-NNRTI-containing regimen may be the preferred initial therapy for newly diagnosed HIV-1 patients in Shanghai in the absence of PDR test results.

Pretreatment drug resistance (PDR) poses an increasing threat to the success of antiretroviral treatment (ART) programs in China. We aimed to conduct a survey of PDR among HIV patients in an area in Southwest China with extensive drug trafficking.Consecutive cross-sectional surveys were conducted in Liangshan Prefecture of Sichuan Province from 2009 to 2018 based on the WHO-recommended method. PDR was identified by testing pol region sequences with the Stanford HIVdb algorithm (version 7.0). PDR prevalence and related factors were assessed by multivariable logistic regression. The transmission of HIV drug resistance was analyzed using a genetic transmission network.HIV-1 pol genes from 1889 patients were successfully amplified. The distribution of HIV- 1 genotypes was as follows: CRF07_BC (94.0%), CRF08_BC (2.3%), CRF01_AE (2.0%) and others (1.4%). Of the participants, 6.9% (95% CI: 4.1-8.1%) had pretreatment resistance to 12 antiretroviral drugs recommended by the WHO, and nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitors (PI) resistance were identified among 1.4% (95% CI: 0.7-3.4%), 5.8% (95% CI: 1.2-8.7%) and 0.4% (95% CI: 0.1- 3.0%) of the patients, respectively. In the multivariate logistic model, the prevalence of PDR was 1.52-fold higher among intravenous drug users (IDUs) than among patients infected by heterosexual transmission (95% CI: 1.07-2.38; P=0.049), and the prevalence of PDR among patients diagnosed from 2017-2018 was 2.03-fold higher than that among patients diagnosed from 2009-2016 (95% CI: 1.18-5.76; P=0.018). A total of 26 clusters containing PDR and a rapidly growing drug resistancerelated cluster containing the E138Q and V179D mutations were identified by genetic transmission network analysis.The results show a moderate overall level of PDR prevalence and rapidly growing drug resistance over time. Preventive intervention should be focused on controlling the HIV epidemic among drug users, and surveillance is urgently needed to monitor the trend of PDR.Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.

Introduction: Transmitted drug resistance (TDR) can compromise antiretroviral therapy (ART) efficacy. We aimed to understand the molecular epidemiology of TDR and its genetic transmission networks among newly diagnosed people living with HIV/AIDS (PLWH).

Sichuan province is one of the highest AIDS epidemic provinces in China, with a large number of floating population. The annual number of cases of HIV/AIDS reported in Sichuan has been the highest province in China for several successive years. There is a lack of widespread and representative data on the distribution of HIV genotypes in Sichuan. We aim to investigate the characteristics of HIV-1 molecular epidemiology and transmitted drug-resistance in newly diagnosed HIV-infected patients in Sichuan, China.Archived plasma samples (n = 1524) from HIV-1 newly-diagnosed individuals in April 2019 were selected by cross-sectional investigation from all 21 cities in Sichuan province. Phylogenetic relationship, transmission cluster, and genotypic drug resistance analyses were performed using HIV-1 polymerase (pol) gene sequences. We also analysed the association of demographic and virological factors with transmitted drug-resistance (TDR) and transmission clusters.Partial pol gene sequences were obtained from 1297 cases. HIV-1 epidemic strains in Sichuan province: the majority of genotypes were circulating recombinant form (CRF) 07_BC (675, 52.04%), CRF01_AE (343, 26.45%), CRF08_BC (115, 8.87%), CRF85_BC (67, 5.17%), subtype B (33, 2.54%), the other genotypes only accounted for 4.93%, and unique recombinant forms (URFs) (23, 1.77%) were observed in the study, and the difference of age, ethnicity, education, occupation, region and transmission pathway of different genotypes were statistically significant. According to WHO HIVDR surveillance threshold, the level of TDR has reached a medium level, with 72 of 1297 (5.55%) cases carrying drug-resistance mutation sites, TDR mutation frequency to nonnucleoside reverse transcriptase inhibitors (NNRTIs, 3.85%) was much higher than nucleoside reverse transcriptase inhibitors (NRTIs, 0.31%) and protease inhibitors (PIs, 1.70%), and CRF08_BC was a risk factor for TDR (odds ratio, 8.32; 95% CI 4.38-15.80 for CRF07_BC, P < 0.05). The most common drug resistance HIV-1 mutation pattern for NNRTI was V106 (1.31%, 17/1297) and E138 (1.16%, 15/1297), and for PI was M46 (0.69%, 9/1297). A total of 205 (15.8%) pol sequences were involved in the genetic transmission network clusters, CRF01_AE (odds ratio, 2.369; 95% CI 1.659-3.382; P < 0.05), subtype B (odds ratio, 13.723; 95% CI 6.338-29.71; P < 0.05), drug resistance (odds ratio, 0.306; 95% CI 0.106-0.881; P < 0.05) and different levels of education (P < 0.05) were significantly associated to be in clusters.The distribution of HIV-1 genotypes in Sichuan is more diverse and complex, and the Men who have sex with men (MSM) is underrated, arguing for behavior scaling up intervention in this specific population besides the elderly people with heterosexual transmission risk groups. The risk of TDR mutation frequency increased in newly diagnosed patients highlights the significance of genotypic drug resistance monitoring and molecular surveillance of pretreatment HIV-1 drug resistance. The regimen composed of TDF, 3TC and EFV was still currently the preferred solution used free first-line therapy.© 2022. The Author(s).

Background: The emergence of an HIV-1 epidemic in China was first recognized in Dehong, western Yunnan. Due to its geographic location, Dehong contributed greatly in bridging HIV-1 epidemics in Southeast Asia and China through drug trafficking and injection drug use; and also extensively to the HIV genetic diversity in Yunnan and China. We attempt to monitor HIV-1 in this area by studying the HIV-1 genetic distribution and transmitted drug resistance (TDR) in various at-risk populations.;Methods: Blood samples from a total of 320 newly HIV-1 diagnosed individuals, who were antiretroviral therapy (ART)-naive, were collected from January 2009 to December 2010 in 2 counties in Dehong. HIV-1 subtypes and pol gene drug resistance (DR) mutations were genotyped.;Results: Among 299 pol sequences successfully genotyped (93.4%), subtype C accounted for 43.1% (n=129), unique recombinant forms (URFs) for 18.4% (n=55), CRF01_AE for 17.7% (n=54), B for 10.7% (n=32), CRF08_BC for 8.4% (n=25) and CRF07_BC for 1.7% (n=5). Subtype distribution in patients infected by different transmission routes varied. In contract to the previous finding of CRF01_AE predominance in 2002-2006, subtype C predominated in both injecting drug users (IDUs) and heterosexually transmitted populations in this study. Furthermore, we found a high level of BC, CRF01_AE/C and CRF01_AE/B/C recombinants suggesting the presence of active viral recombination in the area. TDR associated mutations were identified in 4.3% (n=13) individuals. A total of 1.3% of DR were related to protease inhibitors (PIs), including I85IV, M46I and L90M; 0.3% to nucleoside reverse transcriptase inhibitors (NRTIs), including M184I; and 2.7% to non-nucleoside reverse transcriptase inhibitors (NNRTIs), including K103N/S, Y181C, K101E and G190A.;Conclusion: Our work revealed diverse HIV-1 subtype distributions and intersubtype recombinations. We also identified a low but significant TDR mutation rate among ART-naive patients. These findings enhance our understanding of HIV-1 evolution and are valuable for the development and implementation of a comprehensive public health approach to HIV-1 DR prevention and treatment in the region.

HIV-1 drug resistance can compromise the effectiveness of antiretroviral therapy (ART). A survey of pretreatment HIV-1 drug resistance (PDR) was conducted in Lincang Prefecture of Yunnan Province. From 372 people living with HIV/AIDS initiating ART for the first time during 2017–2018, 322 pol sequences were obtained, of which 11 HIV-1 strain types were detected. CRF08_BC (70.2%, 226/322) was the predominant strain, followed by URF strains (10.6%, 34/322). Drug resistance mutations (DRMs) were detected among 34.2% (110/322) of the participants. E138A/G/K/R (14.3%, 46/322) and V179E/D/T (13.7%, 47/322) were the predominant DRMs. Specifically, E138 mutations commonly occurred in CRF08_BC (19.9%, 45/226). Among the DRMs detected, some independently conferred resistance, such as K65R (1.6%, 5/322), Y188C/F/L (0.9%, 3/322), K103N (0.6%, 2/322) and G190A (0.3%, 1/322), which conferred high-level resistance. The prevalence of PDR was 7.5% (95% CI: 4.6–10.3%) and the prevalence of non-nucleotide reverse transcriptase inhibitor (NNRTI) resistance was 5.0% (95% CI: 2.6–7.4%), which is below the threshold (⩾10%) of initiating a public health response. In conclusion, HIV-1 genetic diversity and an overall moderate level of PDR prevalence were found in western Yunnan. PDR surveillance should be continually performed to decide whether a public health response to NNRTI resistance should be initiated.

This study aimed to investigate the prevalence of HIV pretreatment drug resistance (PDR) and the transmission clusters associated with PDR-related mutations in newly diagnosed, treatment-naive patients between 2020 and 2023 in Dehong prefecture, Yunnan province, China.Demographic information and plasma samples were collected from study participants. PDR was assessed using the Stanford HIV Drug Resistance Database. The Tamura-Nei 93 model within HIV-TRACE was employed to compute pairwise matches with a genetic distance of 0.015 substitutions per site.Among 948 treatment-naive individuals with eligible sequences, 36 HIV subtypes were identified, with unique recombinant forms (URFs) being the most prevalent (18.8%, 178/948). The overall prevalence of PDR was 12.4% (118/948), and resistance to non-nucleotide reverse transcriptase inhibitors (NNRTIs), nucleotide reverse transcriptase inhibitors (NRTIs), and protease inhibitors (PIs) was 10.7%, 1.3%, and 1.6%, respectively. A total of 91 clusters were identified, among which eight showed evidence of PDR strain transmission. The largest PDR-associated cluster consisted of six CRF01_AE drug-resistant strains carrying K103N and V179T mutations; five of these individuals had initial CD4+ cell counts < 200 cells/μL.The distribution of HIV subtypes in Dehong is diverse and complex. PDR was moderately prevalent (12.4%) between 2020 and 2023. Evidence of transmission of CRF01_AE strains carrying K103N and V179T mutations was found. Routine surveillance of PDR and the strengthening of control measures are essential to limit the spread of drug-resistance HIV strains.Copyright © 2025 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

To investigate the prevalence of HIV-1 genotypic mutations for drug resistance among patients in Beijing, blood samples from 145 newly confirmed (2006–2007), treatment-naive HIV-1-infected individuals were analyzed. Seven subtypes or CRF were subsequently determined and scored by the Stanford HIV Drug Resistance algorithm: CRF01_AE HIV-1 (27.6%), subtype B′ (24.1%), CRF07_BC (21.4%), subtype B (20.7%), CRF08_BC (3.4%), subtype C (2.1%), and CRF06_cpx (0.7%). Eleven of the 145 subjects studied were found to harbor the strains resistant to either protease inhibitors (PIs) (3.4%), or nucleoside reverse transcriptase inhibitors (NRTIs) (2.1%), or nonnucleoside reverse transcriptase inhibitors (NNRTIs) (3.4%). Although the prevalence of drug resistance was relatively low among the treatment-naive HIV-1 patients in Beijing in comparison to those in industrialized countries, we will continue monitoring newly infected subjects for any potential alteration of the prevalence pattern to ensure the success of the ongoing scale-up of antiretroviral treatment.

To optimise patients' outcomes and gain insight into transmitted drug resistance (TDR) among human immunodeficiency virus (HIV)-1 treatment-naive patients in Beijing, the prevalence of TDR was assessed. Demographic and clinical data of 1241 treatment-naive patients diagnosed between April 2014 and February 2015 were collected. TDR was defined using the Stanford University HIV drug resistance mutations database. The risk factors were evaluated by multi-logistic regression analysis. Among 932 successfully amplified cases, most were male (96.78%) and infected through men having sex with men (91.74%). Genotype were CRF01_AE (56.44%), B (20.60%), CRF07_BC (19.96%), C (1.61%) and other genotypes (1.39%). The overall prevalence of TDR was 6.12%. Most frequent mutations occurred in non-nucleoside reverse transcriptase inhibitors (NNRTIs) (3.11%), followed by protease inhibitors (PIs) (2.25%) and nucleoside reverse transcriptase inhibitors (NRTIs) (1.32%). Furthermore, HIV-1 genotype was associated with high risk of resistance, in which genotype C and other genotype may have higher risk for resistance. The prevalence among treatment-naive patients in Beijing was low. Resistance to NNRTIs was higher than with PIs or NRTIs. Continuous monitoring of regional levels of HIV-1 TDRs would contribute to improve treatment outcomes and prevent failures.

\n Diversity of genotypes and prevalence of pretreatment drug resistance (PDR) are challenges for the epidemic control and vaccine development of HIV-1. However, little is known about the situation in Tianjin. Blood samples were collected from newly diagnosed, antiretroviral treatment (ART)-naive HIV/AIDS patients from January 2016 to November 2019. The target fragment in the\n pol\n gene was sequenced after RNA extraction and gene amplification. The HIV-1 genotype was identified by phylogenetic analysis. Drug resistance was carried out using the Stanford University HIVdb algorithm. A total of 305\n pol\n sequences from 279 non-PDR individuals and 35 PDR individuals were successfully amplified. The most prevalent genotype was CRF01_AE (65.6%, 200/305), followed by CRF07_BC (22.0%, 67/305) and B (3.0%, 9/305). A variety of circulating recombinant forms (CRFs) and unique recombinant forms were found. The overall incidence of PDR was 11.5% (35/305), with 9.8% (30/305) to non-nucleoside reverse transcriptase (RT) inhibitors (NNRTIs). The most frequent mutation pattern against NNRTIs was V179D/E/T (6.9%, 21/305), with M184V (1.0%, 3/305) and K65R (1.0%, 3/305) against nucleoside RT inhibitors (NRTIs). M64L (0.1%, 1/305) was the sole mutation found against protease inhibitors (PIs). Eight variants generated at least low-level resistance to NNRTIs (2.6%, 8/305), which was much higher than that to NRTIs (1.6%, 5/305) and PIs (0/305) (\n p\n  < .05). Genotypic drug resistance testing before initiating ART in newly diagnosed HIV/AIDS patients may be necessary in Tianjin, China. The non-NNRTI-based regimen may be preferred as initial therapy in Tianjin.\n

Background: To understand HIV-1 drug resistance in 11 prefectures of Hebei Province, China, we implemented a cross-sectional HIV-1 molecular epidemiological survey.Methods: Blood samples were collected from 122 newly diagnosed drug-naive HIV-1-positive individuals and 229 antiretroviral therapy (ART)-failure individuals from 11 prefectures in Hebei Province, China. Patient demographic data were obtained via face-to-face interviews using a standardized questionnaire when blood samples were collected. Genotyping of HIV-1 drug resistance (DR) was implemented using an in-house assay.Results: In this study, the overall prevalence of HIV-1 DR was 35.5%. The prevalence of HIV-1 DR in participants experiencing treatment failure and ART-naive participants was 51.9 and 5.9%, respectively. Mutations in protease inhibitors, nucleoside reverse transcriptase inhibitors (NRTIs), and non-NRTI (NNRTIs), as well as dual and multiple mutations were extensively seen in participants experiencing treatment failure. The proportions of NNRTI mutations (chi(2) = 9.689, p = 0.002) and dual mutations in NRTIs and NNRTIs (chi(2) = 39.958, p < 0.001) in participants experiencing treatment failure were significantly higher than those in ART-naive participants. The distributions of M184V/I and M41L mutations differed significantly among three main HIV-1 genotypes identified. Viral load, symptoms in the past 3 months, CD4 counts, transmission route, and the duration of ART were found to be associated with HIV-1 DR.Conclusions: Our results suggest that new prevention and control strategies should be formulated according to the epidemic characteristics of HIV-1-resistant strains in Hebei Province, where antiretroviral drugs are widely used.

Human immunodeficiency virus type 1 (HIV-1) genetic diversity and pre-treatment drug resistance (PDR) are major barriers to successful antiretroviral therapy (ART). In China, sexual intercourse is the most frequent route of HIV-1 transmission. However, few studies have analyzed PDR and transmission networks in detail among individuals in China with acute HIV-1 infection and their sexual contacts.

Transmitted drug resistance (TDR) is becoming an obstacle to the success of antiretroviral therapy (ART) as the HIV epidemic continues to spread. This study aimed to investigate the characteristics of TDR and the molecular epidemiology of ART-naive HIV-1 infections in Lishui.A total of 481 plasma samples were collected from ART-naive HIV-1 infections in Lishui between 2020 and 2023. The sequences acquired from infections were used to analyze the characteristics of genotype, TDR, and molecular transmission network.This study discovered that the three most prevalent subtypes among the 455 sequences successfully obtained from infections in Lishui were CRF08_BC (35.8%), CRF07_BC (26.4%), and CRF01_AE (25.9%). The overall prevalence of TDR was 12.1%, and the K103N (2.4%) was the most frequent mutation. Multivariate analysis showed that CRF08_BC (OR = 5.401, P < 0.001) and CD4 cell concentration of 200-499 cells/µL (OR = 1.684, P = 0.030) were associated with a higher risk of entering the molecular transmission network and clustering, whereas the current address in other cities (OR = 0.328, P = 0.004), junior middle school (OR = 0.472, P = 0.006), and junior college or above (OR = 0.387, P = 0.045) were associated with a lower risk of clustering.This study revealed that the prevalence of TDR was at an intermediate level of drug resistance, and high levels of resistance were predominantly concentrated in efavirenz (EFV) and nevirapine (NVP) among the NNRTIs. Middle-aged and older infections represented a significant proportion of the molecular transmission network. This suggests that HIV surveillance and targeted prevention and treatment interventions are essential to reduce the risk of HIV transmission.© 2025. The Author(s).

Transmitted drug resistance (TDR) increases the risk of antiretroviral therapy (ART) failure in HIV-1 patients. This study investigated the molecular epidemiology of TDR and its transmission networks among newly diagnosed HIV-1 patients in Wenzhou, China.We enrolled 1878 ART-naive HIV-1 patients from January 2020 to October 2023. TDR was evaluated using the Stanford University HIV Drug Resistance Database. We performed phylogenetic analysis, genotyping, transmission clustering, and population-based TDR-related factor analysis.Among 1782 patients with successful genotyping, TDR prevalence was 5.7%. Multivariable analysis identified CRF08_BC subtype (adjusted odds ratio [aOR] 18.59, 95% CI 3.79-336.18, p = 0.004), CD4 > 500 cells/mm³ (aOR 2.19, 95% CI 1.16-4.03, p = 0.013), and year 2023 (aOR 1.83, 95% CI 1.11-4.89, p = 0.039) as factors associated with higher TDR risk. The most prevalent NNRTI mutations were K103N, E138A, and V179E. Seven TDR transmission clusters were identified, notably one with V179D that expanded during 2020-2023.While TDR prevalence in Wenzhou remained lower than in other Chinese regions, an upward trend was observed. Most resistant individuals were in transmission clusters, predominantly middle-aged and elderly. NNRTI resistance was severe and concentrated in efavirenz, nevirapine, and rilpivirine. Enhanced HIV surveillance and wider free antiretroviral options are crucial to control drug-resistant HIV spread in Wenzhou.© 2024. The Author(s).

Pretreatment drug resistance (PDR) is becoming an obstacle to the success of ART. This study investigated the prevalence of PDR and the transmission clusters (TCs) of drug resistance mutations (DRMs) in two cities where drug abuse used to be high to describe the local HIV-1 transmission dynamics.

Transmitted drug resistance (TDR) is a major challenge in the clinical management of acquired immunodeficiency syndrome (AIDS). Therefore, this study aimed to investigate the epidemic characteristics of and risk factors for human immunodeficiency virus (HIV)-1 TDR in Nanjing from 2018 to 2021 to provide support for clinical management.The HIV-1 Pol gene was amplified by nested reverse transcription polymerase chain reaction from venous blood of 1190 HIV-infected patients who did not receive antiviral therapy, and the amplified product was sequenced using an in-house sequencing method. The sequencing result was compared with the HIV drug resistance database from Stanford University to elucidate the rates of antiviral drug resistance and distribution of drug-resistant mutation sites. Factors associated with TDR were evaluated using a logistic regression model.Detection of drug resistance at the gene level was successful in 1138 of 1190 HIV-1-infected patients (95.6%), and the overall 4-year drug resistance rate was 8.2% (93/1138). The drug resistance rate was higher for non-nucleoside reverse transcriptase inhibitors (NNRTIs; 6.7%) than for nucleoside reverse transcriptase inhibitors (NRTIs; 2.5%) or protease inhibitors (PIs; 0.1%) (= 83.907, P<0.0001). The most common NNRTI-related mutation was V179D/E followed by K103N. M184V was the dominant NRTI-associated mutation, and M46L/I was the most prevalent PI-associated mutation. A CD4 T cell count of <50 cells/μL was significantly associated with an increased risk of TDR (OR=3.62, 95% CI: 1.38-9.51, P=0.009).The prevalence of TDR in the city of Nanjing from 2018 to 2021 was at a moderate epidemic risk according to World Health Organization standards. Continuous monitoring of TDR can inform clinical diagnosis and treatment. Patients with advanced disease and a low CD4 T lymphocyte count are more likely to have TDR in Nanjing.© 2023 Su et al.

Transmitted drug resistance (TDR) is an increasingly prevalent problem worldwide, which will significantly compromise the effectiveness of HIV treatments. However, in Nanjing, China, there is still a dearth of research on the prevalence and transmission of TDR among ART-naïve HIV-1-infected individuals. This study aimed to understand the prevalence and transmission of TDR in Nanjing.

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.

HIV drug resistance (HIVDR) has become a threat to the elimination of the AIDS epidemic due to the global scale-up of antiretroviral therapy (ART) for HIV-infected individuals. This study aims to investigate the epidemiological dynamics and molecular characterization of HIV pretreatment drug resistance (PDR) and acquired drug resistance (ADR) in Hangzhou, a developed region in China.

HIV/AIDS remains a global public health problem, and understanding the structure of social networks of people living with HIV/AIDS is of great importance to unravel HIV transmission, propose precision control and reduce new infections. This study aimed to investigate the epidemiological characteristics of HIV transmission in Fujian province, southeastern China from 2015 to 2020 based on HIV molecular network.

Highly-active antiretroviral therapy (HAART) was scaled up in Guangxi, China in 2005. The number of individuals receiving free HAART increased dramatically from June 2010 under the Guangxi Government's anti-HIV programme. We aimed to determine the prevalence of HIV-transmitted drug resistance (TDR) of Guangxi.HIV-positive, antiretroviral-naive individuals were recruited from the east (Hezhou), south (Qinzhou), west (Baise), north (Guilin) and centre (Laibin) of Guangxi. The pol gene of the virus from the individuals was analysed.The overall prevalence of HIV TDR was 3.2% (7/216, 95% CI 0.9-5.5). The prevalence rates in Baise, Guilin, Hezhou, Qinzhou and Laibin are 4.9% (2/41, 95% CI -1.7 to 11.5), 2.3% (1/44, 95% CI -2.1 to 5.7), 4.7% (2/43, 95% CI -1.6 to 11.0), 2.6% (1/38, 95% CI -2.5 to 7.7) and 2.0% (1/50, 95% CI -1.9 to 5.9), respectively. No significant difference in the prevalence was found among them. No factors were found to be associated with TDR, including CD4 cell counts, viral loads and genotypes. The subtypes CRF01_AE, CRF07_BC, CRF08_BC and B were found. Subtype CRF08_BC is the predominant subtype in Baise while CRF01_AE is the predominant subtype elsewhere in Guangxi.The prevalence of TDR in antiretroviral-naive patients in Guangxi remains low 8 years after scale-up of HAART.© 2014 S. Karger AG, Basel

Integrase strand transfer inhibitors (INSTIs) are a class of antiretroviral agents used to treat HIV. These drugs--raltegravir, elvitegravir, and dolutegravir--are preferred options for treatment-naïve patients when used in combination with two nucleoside reverse transcriptase inhibitors. Based on clinical trials, INSTIs have been proven to be effective with minimal safety concerns. This article reviews the pharmacologic profile, role in therapy, and safety and efficacy of each agent.

Current antiretrovirals (ARVs) have demonstrated the ability to prolong the life of an HIV infected individual via suppression of the virus and subsequent restoration of immune function. Despite significant advancement, there remains an opportunity for improvement. One ARV that attempts to fill global HIV therapeutic needs by balancing convenience, safety, and efficacy is elvitegravir (EVG). Areas covered: Using MEDLINE/PubMed, a literature search was conducted for published articles on the safety and efficacy of EVG in the treatment of HIV infection. Expert opinion: EVG offers clinicians a convenient choice for HIV-positive patients that is safe and effective for both treatment-naïve and experienced patients, as well as an option for regimen simplification in virologically suppressed patients. EVG is conveniently co-formulated in fixed dose combination tablets to be taken once daily with food. EVG does not require dose adjustment for patients with severe renal impairment or mild to moderate liver disease. Importantly, EVG requires co-administration with a pharmacokinetic enhancer (i.e., ritonavir or cobicistat) in order to achieve therapeutic levels and facilitate once daily dosing. As a consequence, clinicians must carefully review concomitant medications and navigate potential drug-drug interactions mediated through potent inhibition of cytochrome P450 3A enzymes by ritonavir and cobicistat.

Human immunodeficiency virus type-1 (HIV-1) integrase is one of the three virally encoded enzymes required for replication and therefore a rational target for chemotherapeutic intervention in the treatment of HIV-1 infection. We report here the discovery of Raltegravir, the first HIV-integrase inhibitor approved by FDA for the treatment of HIV infection. It derives from the evolution of 5,6-dihydroxypyrimidine-4-carboxamides and N-methyl-4-hydroxypyrimidinone-carboxamides, which exhibited potent inhibition of the HIV-integrase catalyzed strand transfer process. Structural modifications on these molecules were made in order to maximize potency as HIV-integrase inhibitors against the wild type virus, a selection of mutants, and optimize the selectivity, pharmacokinetic, and metabolic profiles in preclinical species. The good profile of Raltegravir has enabled its progression toward the end of phase III clinical trials for the treatment of HIV-1 infection and culminated with the FDA approval as the first HIV-integrase inhibitor for the treatment of HIV-1 infection.

Integrase mutations can reduce the effectiveness of the first-generation FDA-approved integrase strand transfer inhibitors (INSTIs), raltegravir (RAL) and elvitegravir (EVG). The second-generation agent, dolutegravir (DTG), has enjoyed considerable clinical success; however, resistance-causing mutations that diminish the efficacy of DTG have appeared. Our current findings support and extend the substrate envelope concept that broadly effective INSTIs can be designed by filling the envelope defined by the DNA substrates. Previously, we explored 1-hydroxy-2-oxo-1,2-dihydro-1,8-naphthyridine-3-carboxamides as an INSTI scaffold, making a limited set of derivatives, and concluded that broadly effective INSTIs can be developed using this scaffold. Herein, we report an extended investigation of 6-substituents as well the first examples of 7-substituted analogues of this scaffold. While 7-substituents are not well-tolerated, we have identified novel substituents at the 6-position that are highly effective, with the best compound (6p) retaining better efficacy against a broad panel of known INSTI resistant mutants than any analogues we have previously described.

The use of highly active antiretroviral therapy against human immunodeficiency virus (HIV) can lead to rare instances of treatment failure and the emergence of drug resistance. HIV drug-resistant strains are archived in cellular reservoirs, and this can exclude the future efficacy of drugs or drug classes against which resistance has emerged. In addition, drug-resistant viruses can be transmitted between individuals. HIV drug resistance has been countered through the constant development of new antiretroviral drugs. Integrase strand transfer inhibitors, that actively block the integration of the HIV genome into the host DNA, represent the most recent antiretroviral drugs. Of these, raltegravir, elvitegravir, and dolutegravir are the only integrase strand transfer inhibitors that have been approved for human therapy by the US Food and Drug Administration. Dolutegravir is unique in its ability to seemingly evade HIV drug resistance in treatment-naïve individuals. Here, we review the use of integrase strand transfer inhibitors in the management of HIV, focusing on HIV resistance.

Dolutegravir (GSK1349572), a once-daily HIV integrase inhibitor, has shown potent antiviral response and a favourable safety profile. We evaluated safety, efficacy, and emergent resistance in antiretroviral-experienced, integrase-inhibitor-naive adults with HIV-1 with at least two-class drug resistance.ING111762 (SAILING) is a 48 week, phase 3, randomised, double-blind, active-controlled, non-inferiority study that began in October, 2010. Eligible patients had two consecutive plasma HIV-1 RNA assessments of 400 copies per mL or higher (unless >1000 copies per mL at screening), resistance to two or more classes of antiretroviral drugs, and had one to two fully active drugs for background therapy. Participants were randomly assigned (1:1) to once-daily dolutegravir 50 mg or twice-daily raltegravir 400 mg, with investigator-selected background therapy. Matching placebo was given, and study sites were masked to treatment assignment. The primary endpoint was the proportion of patients with plasma HIV-1 RNA less than 50 copies per mL at week 48, evaluated in all participants randomly assigned to treatment groups who received at least one dose of study drug, excluding participants at one site with violations of good clinical practice. Non-inferiority was prespecified with a 12% margin; if non-inferiority was established, then superiority would be tested per a prespecified sequential testing procedure. A key prespecified secondary endpoint was the proportion of patients with treatment-emergent integrase-inhibitor resistance. The trial is registered at ClinicalTrials.gov, NCT01231516.Analysis included 715 patients (354 dolutegravir; 361 raltegravir). At week 48, 251 (71%) patients on dolutegravir had HIV-1 RNA less than 50 copies per mL versus 230 (64%) patients on raltegravir (adjusted difference 7·4%, 95% CI 0·7 to 14·2); superiority of dolutegravir versus raltegravir was then concluded (p=0·03). Significantly fewer patients had virological failure with treatment-emergent integrase-inhibitor resistance on dolutegravir (four vs 17 patients; adjusted difference -3·7%, 95% CI -6·1 to -1·2; p=0·003). Adverse event frequencies were similar across groups; the most commonly reported events for dolutegravir versus raltegravir were diarrhoea (71 [20%] vs 64 [18%] patients), upper respiratory tract infection (38 [11%] vs 29 [8%]), and headache (33 [9%] vs 31 [9%]). Safety events leading to discontinuation were infrequent in both groups (nine [3%] dolutegravir, 14 [4%] raltegravir).Once-daily dolutegravir, in combination with up to two other antiretroviral drugs, is well tolerated with greater virological effect compared with twice-daily raltegravir in this treatment-experienced patient group.ViiV Healthcare.Copyright © 2013 Elsevier Ltd. All rights reserved.

The integrase strand transfer inhibitors (INSTIs) are the newest antiretroviral class in the HIV treatment armamentarium. Dolutegravir (DTG) is the only second-generation INSTI with FDA approval (2013). It has potential advantages in comparison to first-generation INSTI's, including unboosted daily dosing, limited cross resistance with raltegravir and elvitegravir, and a high barrier to resistance. Clinical trials have evaluated DTG as a 50-mg daily dose in both treatment-naïve and treatment-experienced, INSTI-naïve participants. In those treatment-naïve participants with baseline viral load <100,000 copies/mL, DTG combined with abacavir and lamivudine was non-inferior and superior to fixed-dose combination emtricitabine/tenofovir/efavirenz. DTG was also superior to the protease inhibitor regimen darunavir/ritonavir in treatment-naïve participants regardless of baseline viral load. Among treatment-experienced patients naïve to INSTI, DTG (50 mg daily) demonstrated both non-inferiority and superiority when compared to the first-generation INSTI raltegravir (400 mg twice daily) regardless of the background regimen. No phenotypically significant DTG resistance has been demonstrated in INSTI-naïve participant trials. The VIKING trials evaluated DTG's ability to treat persons with HIV with prior INSTI exposure. VIKING demonstrated twice-daily DTG was more efficacious than daily dosing when treating participants receiving and failing first-generation INSTI regimens. DTG maintained potency against single mutations from any of the three major INSTI pathways (Y143, H155, Q148); however, the Q148 mutation with two or more additional mutations significantly reduced its potency. The long-acting formulation of DTG, GSK1265744LA, is the next innovation in this second-generation INSTI class, holding promise for the future of HIV prevention and treatment.

The review addresses the role of dolutegravir (DTG) in first-line therapy. In the era of test and treat, where United Nations AIDS Program and WHO have set the ambitious targets of 90/90/90, new efficacious, well tolerated, and simple therapeutic options are needed.DTG has been tested in large clinical trials in treatment-naïve patients, showing noninferiority to raltegravir and superiority compared with efavirenz and ritonavir-boosted darunavir, respectively. The main features of DTG are reviewed in this study, including efficacy, safety, high-resistance barrier, daily treatment schedule, and coformulation as single-tablet regimen. Use of DTG in special populations is also reviewed. Tolerability, with focus in neuropsychiatric disturbances is discussed in particular. DTG has shown high efficacy level, tested in males and females, has no limitations in patients with renal and/or hepatic impairment and is available as single drug (to be combined with two nucleoside reverse transcriptase inhibitors in fixed combinations) or as a single-tablet regimen combined with abacavir and lamivudine.DTG is an excellent candidate for initial therapy in HIV-infected patients. If safety of DTG in pregnant women are confirmed by ongoing studies, DTG might become the first option in WHO antiretroviral guidelines.

Integrase strand transfer inhibitors (INSTIs) are the newest class of antiretroviral drugs to be approved for treatment and act by inhibiting the essential HIV protein integrase from inserting the viral DNA genome into the host cell's chromatin. Three drugs of this class are currently approved for use in HIV-positive individuals: raltegravir (RAL), elvitegravir (EVG), and dolutegravir (DTG), while cabotegravir (CAB) and bictegravir (BIC) are currently in clinical trials. RAL and EVG have been successful in clinical settings but have relatively low genetic barriers to resistance. Furthermore, they share a high degree of cross-resistance, which necessitated the development of so-called second-generation drugs of this class (DTG, CAB, and BIC) that could retain activity against these resistant variants. In vitro selection experiments have been instrumental to the clinical development of INSTIs, however they cannot completely recapitulate the situation in an HIV-positive individual. This review summarizes and compares all the currently available information as it pertains to both in vitro and in vivo selections with all five INSTIs, and the measured fold-changes in resistance of resistant variants in in vitro assays. While the selection of resistance substitutions in response to RAL and EVG bears high similarity in patients as compared to laboratory studies, there is less concurrence regarding the "second-generation" drugs of this class. This highlights the unpredictability of HIV resistance to these inhibitors, which is of concern as CAB and BIC proceed in their clinical development.

Dolutegravir (DTG) is now recommended to all HIV infected adults, adolescents, and children of right age by WHO. The low cost of $75 per year for generic DTG-based combination, has allowed 3·9 million people living with HIV (PLWH) in low and middle-income countries (LMICs) access to DTG. Lamivudine and emtricitabine associated M184V/I mutation is highly prevalent in PLWH and the majority of HIV infected individuals receiving DTG regimens may already be carrying M184V/I mutation.Despite high prevalence of M184V/I in antiretroviral therapy (ART) experienced patients, DTG treatment outcomes will likely not be adversely affected by this mutation. The use of DTG in ART naïve has been largely characterised by rare emergence of resistance and virological failure. DTG-based regimens have to great extent been effective at maintaining viral suppression in treatment experienced PLWH carrying M184V/I.Initiating patients on DTG may help preserve more treatment options for HIV infected individuals living in LMICs. High genetic barrier to the development of resistance associated with DTG and progressive viral suppression in patients switched to DTG-based therapy with M184V/I, may encourage better DTG outcomes and help in curbing increasing levels of HIV drug resistance in LMICs.Copyright © 2021. Published by Elsevier Ltd.

Integrase inhibitors (INIs) are the latest class of antiretroviral drugs approved for the treatment of HIV infection and are becoming 'standard' drugs in the treatment of both naïve as well as heavily pretreated individuals with HIV.Data on efficacy, safety, tolerability, pharmacokinetics, drug-drug interactions and resistance are reviewed from the pivotal Phase III clinical trials published in PubMed high-impact medical journals or presented at international meetings.Due to their outstanding data of efficacy, tolerability, safety--shared by all three drugs (raltegravir, elvitegravir, dolutegravir) currently belonging to this new family of antiretrovirals--INIs have become part of the recommended initial antiretroviral therapy options. Some differences in dosing, drug-drug interactions and robustness/genetic barrier among the three drugs will provide the physician the characteristics to make the best choice.

Data on integrase inhibitor resistance come primarily from clinical trials and in vitro studies. We examined results of all clinically indicated integrase genotypic resistance tests (GRTs) performed at a US national referral lab from 2009 through 2012.Integrase sequences and demographic data were compiled with paired protease-reverse transcriptase (PR-RT) GRT results, when available. Analyses utilized the Stanford HIV Drug Resistance Database. "Major" integrase mutations included T66AIK, E92QV, F121Y, Y143CHR, S147G, Q148HKR, and N155H; multiple accessory mutations were also assessed.Among 3294 sequences from 3012 patients, 471 patients had viruses with ≥ 1 raltegravir or elvitegravir resistance mutation (15.6%). Q148 and N155 pathways were equally represented (both n = 197); 84 had Y143 mutations. Q148 rarely occurred without accessory mutations (n = 3). Among 224 patients with serial integrase GRTs, 22 with baseline wild-type acquired a major mutation, after a median 224 days between tests (interquartile range, 148-335 days). Major mutations were observed to persist up to 462 days. Most (62%) had paired PR-RT results. Patients with integrase-resistant viruses were older and more likely to have PR-RT mutations (both P <.001). Among those with PR-RT data, 42 patients had 4-class resistance (2.3%). Sex, geographic region, and test year were not associated with integrase resistance. High-level dolutegravir resistance was predicted in 12% of patients with raltegravir- or elvitegravir-resistant viruses (2% of all patients).Approximately 1 in 6 US patients undergoing integrase GRT for clinical decision making harbors significant resistance, with Q148 and N155 pathways equally common. Dolutegravir is likely to have full or partial activity against most variants observed.

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.To determine the prevalence of INSTI-related mutations among ART-naïve HIV-1-infected adults in Guangdong, China, in 2018.The entire 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.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.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.© 2020 Lan et al.