Protease Inhibitor Resistance Mutations Research Articles

Prevalence of HIV Drug Resistance Mutations among Treatment-Naive People Living with HIV in a Tertiary Care Center in India.

India has the third-largest number of people living with HIV (PLHIV) in the world. A national program provides free access to standard uniform antiretroviral therapy. However, the program is not monitored by comprehensive drug resistance surveys. The aim of this study was to determine the prevalence of HIV drug resistance mutations (DRMs) among treatment-naive PLHIV in a large antiretroviral treatment center of the national program. This cross-sectional study was done in 2017 and involved 200 consecutive treatment-naive PLHIV. A target fragment of 1,306 bp in the reverse transcriptase and protease regions was amplified. Identification of mutations and drug resistance interpretation was done by HIV Genotypic Resistance Interpretation and International Antiviral Society-USA list. Sequencing was successful in 177 samples. The majority (98.8%; 175/177) belonged to subtype C. Nineteen of 177 patients (10.7%; 95% CI: 6.2%-15.3%) had at least one major DRM. The prevalence of non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations was 10.2% (18/177). The most frequent mutations were E138A/K, A98G, K103N, V179D, and K101H/E. The prevalence of nucleoside reverse transcriptase inhibitor (NRTI) mutations was 1.1% (2/177). None of the samples had major protease inhibitor resistance mutations. The prevalence of NNRTI mutations in this study was >10%, crossing the threshold recommended by the WHO to change the NNRTI-based first-line regimen to non-NNRTI based. In 2021, the national program replaced efavirenz with dolutegravir in the first-line regimen of tenofovir, lamivudine, and efavirenz. As the majority (64%) of PLHIV in India are accessing free ART from the national program, this study highlights the need for regular nationally representative drug resistance surveys for optimizing antiretroviral regimens in the program.

Outcome of Darunavir-Cobicistat-Based Regimens in HIV-Infected People Who Have Experienced Virological Failure.

To evaluate the virological outcome of darunavir-cobicistat (DRVc)-based regimens in adults living with HIV who had experienced virological failure (VF) on any previous drug combination. This was a retrospective cohort study (CSLHIV Cohort) of adults living with HIV who started a DRVc-based regimen with HIV-RNA >50 copies/mL after VF on any previous drug combination. Data on demographics, antiretroviral treatment since HIV diagnosis, and immunological and metabolic parameters from baseline (start of DRVc) to 48 weeks were analyzed in order to assess the cumulative proportion of those who achieved virological success (VS), defined as at least one instance of HIV-RNA <50 copies/mL within 12 months from baseline. Follow-up lasted from the start of the DRVc-based regimen (baseline) to the first instance of HIV-RNA <50 copies/mL, last available visit, or lossto follow-up or death, whichever occurred first. Univariate and multivariate Cox proportional-hazard regression models were used to identify baseline factors associated with VS. A total of 176 individuals were included, and 120 (68.2%) achieved <50 HIV-RNA copies/mL within 12 months since baseline. On multivariate analysis, baseline HDL cholesterol was independently associated with the occurrence of VS (adjusted HR 1.021, 95% CI 1.004-1.038; p=0.014). Among the 120 subjects with VS, 27 (22.5%) had had VF during a median follow-up of 20.8 months since the first undetectable HIV-RNA. Resistance testing after VF was available in two cases, which harboured the HIV variant-bearing protease inhibitor-resistance mutations D30N, I50V, and N88D. During a median follow-up of 38.4 months, 65 of 176 (36.9%) individuals discontinued DRVc for any reason (37 of 120, 30.8%) and achieved VS vs. 28 of 56 (50%) without VS (p=0.019). Time to discontinuation was longer in people with VS (41.5 vs. 23.0 months, p=0.0007). No statistically significant changes were observed in immunological or lipid profiles during follow-up. Most individuals in this study achieved VS within 12 months from the beginning of a DRVc-based regimen; therefore, this treatment represent a viable option for people who have experienced VF on other regimens.

Evaluation of a Novel In-house HIV-1 Genotype Drug Resistance Assay using Clinical Samples in China.

BackgroundHIV drug resistance poses a major challenge for anti-retroviral treatment (ART) and the prevention and control of HIV epidemic.ObjectiveThe study aims to establish a novel in-house assay with high efficiency, named AP in- house method, that would be suitable for HIV-1 drug resistance detection in China.MethodsAn in-house HIV-1 genotyping method was used to sequence the partial pol gene from 60 clinical plasma samples; the results of our test were compared with a commercial ViroSeq HIV-1 genotyping system.ResultsAmong sixty samples, 58(96.7%) were successfully amplified by AP in-house method, five of them harbored viral load below 1,000 copies/ml. The genotype distribution was 43.1% CRF07_BC (25/58), 39.7% CRF01_AE (23/58), 6.9% CRF55_01B (4/58), 5.2% subtype B (3/58) and 5.2% CRF08_BC (3/58). Compared with that of the ViroSeq system, the consistent rate of these nucleotides and amino acids obtained by AP in-house method was up to 99.5 ± 0.4% and 99.5 ± 0.4%, respectively. A total of 290 HIV-1 drug resistance mutations were identified by two methods, including 126 nucleoside reverse transcriptase inhibitors (NRTIs), 145 non-nucleoside reverse transcriptase inhibitors (NNRTIs) and 19 protease inhibitors (PIs) resistance mutations. Out of them, 94.1% (273/290) were completely concordant between the AP in-house method and the ViroSeq system. ConclusionOverall, the evaluation of AP in-house method provided comparable results to those of the ViroSeq system on diversified HIV-1 subtypes in China.

HIV-1 Gag Non-Cleavage Site PI Resistance Mutations Stabilize Protease/Gag Substrate Complexes In Silico via a Substrate-Clamp

HIV-1 protease active site inhibitors are a key part of antiretroviral therapy, though resistance can evolve rendering therapy ineffective. Protease inhibitor resistance typically starts with primary mutations around the active site, which reduces inhibitor binding, protease affinity for substrate cleavage site residues P4-P4′, and viral replication. This is often followed by secondary mutations in the protease substrate-grooves which restore viral replication by increasing protease affinity for cleavage site residues P12-P5/P5′-P12′, while maintaining resistance. However, mutations in Gag alone can also result in resistance. The Gag resistance mutations can occur in cleavage sites (P12-P12′) to increase PR binding, as well as at non-cleavage sites. Here we show in silico that Gag non-cleavage site protease inhibitor resistance mutations can stabilize protease binding to Gag cleavage sites which contain structured subdomains on both sides: SP1/NC, SP2/p6, and MA/CA. The Gag non-cleavage site resistance mutations coordinated a network of H-bond interactions between the adjacent structured subdomains of the Gag substrates to form a substrate-clamp around the protease bound to cleavage site residues P12-P12′. The substrate-clamp likely slows protease disassociation from the substrate, restoring the cleavage rate in the presence of the inhibitor. Native Gag substrates can also form somewhat weaker substrate-clamps. This explains the 350-fold slower cleavage rate for the Gag CA/SP1 cleavage site in that the CA-SP1 substrate lacks structured subdomains on both sides of the cleavage site, and so cannot form a substrate-clamp around the PR.

HIV-1 subtypes and profiles of resistance to protease inhibitors in the Marajo Archipelago (Brazilian Amazon region)

The Marajo Archipelago, located in the rural area of ​​the state of Para (Amazon region of Brazil), is the region with the lowest index of human development in the country, presenting poor health services, which makes adequate epidemiological surveillance of HIV-1 infection difficult. After a serological screening enrolling 1,877 samples, three samples were diagnosed with HIV-1 and the pro gene was sequenced to evaluate the presence of resistance mutations to protease inhibitors. Molecular analyses revealed, for the first time in the region of Marajo Island, the occurrence of HIV-1 subtypes B and D, as well as the presence of transmitted high and intermediate protease inhibitors resistance mutations. The results emphasize the importance of ongoing molecular epidemiological surveillance studies in the Brazilian Amazon region because antiretroviral (ARV) resistance mutations may limit treatment options, and the presence of certain subtypes seems to influence the progression to AIDS, particularly in areas where the entry and spread of the virus can be facilitated by socio-demographic problems that expose the population to sexually transmitted infections.

Coevolved Multidrug-Resistant HIV-1 Protease and Reverse Transcriptase Influences Integrase Drug Susceptibility and Replication Fitness.

Integrase strand transfer inhibitors (InSTIs) are recommended agents in first-line combination antiretroviral therapy (cART). We examined the evolution of drug resistance mutations throughout HIV-1 pol and the effects on InSTI susceptibility and viral fitness. We performed single-genome sequencing of full-length HIV-1 pol in a highly treatment-experienced patient, and determined drug susceptibility of patient-derived HIV-1 genomes using a phenotypic assay encompassing full-length pol gene. We show the genetic linkage of multiple InSTI-resistant haplotypes containing major resistance mutations at Y143, Q148 and N155 to protease inhibitor (PI) and reverse transcriptase inhibitor (RTI) resistance mutations. Phenotypic analysis of viruses expressing patient-derived IN genes with eight different InSTI-resistant haplotypes alone or in combination with coevolved protease (PR) and RT genes exhibited similar levels of InSTI susceptibility, except for three haplotypes that showed up to 3-fold increases in InSTI susceptibility (p ≤ 0.032). The replicative fitness of most viruses expressing patient-derived IN only significantly decreased, ranging from 8% to 56% (p ≤ 0.01). Interestingly, the addition of coevolved PR + RT significantly increased the replicative fitness of some haplotypes by up to 73% (p ≤ 0.024). Coevolved PR + RT contributes to the susceptibility and viral fitness of patient-derived IN viruses. Maintaining patients on failing cART promotes the selection of fitter resistant strains, and thereby limits future therapy options.

HSV-2 Infection as a Potential Cofactor for HIV Disease Progression and Selection of Drug Resistance Mutations in Adults under WHO-Recommended First-Line Antiretroviral Therapy: A Multicentric, Cross-Sectional Study in Cameroon, Central African Republic, Chad, and Gabon.

Although herpes simplex virus-2 (HSV-2) infection is a known cofactor for HIV transmission in Central Africa, its role in HIV disease progression is unclear. The aim of this study was to examine the potential link between HSV-2 infection and HIV disease progression, in addition to identifying the presence of genes conferring HIV antiretroviral resistance mutations. This was a cross-sectional study involving 302 HIV-infected adults in Central Africa with virological failure (viral load >1000 copies/mL) on first-line antiretroviral therapy from four different countries. The seroprevalence of HSV-2 was 32% (96/302). Amongst the HIV-infected individuals who were HSV-2 seropositive, the mean HIV viral load and CD4 count were 4.82 ± 0.83 log copies/mL and 243 ± 144 cells/microliter, respectively. Among the HIV-infected individuals who were HSV-2-seronegative, the mean HIV viral load and CD4 count were 3.48 ± 0.44 log copies/mL and 646 ± 212 cells/microliter, respectively (p < 0.001). There was a statistically significant relationship (p < 0.001) between HSV-2 seropositivity and the presence of resistance mutations to antiretrovirals (ARV), non-nucleoside reverse transcriptase inhibitors (NNRTI), and nucleoside reverse transcriptase inhibitors (NRTI) with odds ratios of 9.7, 10, and 11.9, respectively. There was no link between HSV-2 serostatus and protease inhibitor (PI) resistance mutations. There was a substantial accumulation of resistance mutations in HSV-2-seropositive compared to -seronegative patients. These findings support the link between HIV disease progression and HSV-2 infection. An association was observed between the presence of NNRTI and NRTI resistance mutations and HSV-2 seropositivity.

High failure rates of protease inhibitor-based antiretroviral treatment in rural Tanzania - A prospective cohort study.

BackgroundPoor adherence to antiretroviral drugs and viral resistance are the main drivers of treatment failure in HIV-infected patients. In sub-Saharan Africa, avoidance of treatment failure on second-line protease inhibitor therapy is critical as treatment options are limited.MethodsIn the prospective observational study of the Kilombero & Ulanga Antiretroviral Cohort in rural Tanzania, we assessed virologic failure (viral load ≥1,000 copies/mL) and drug resistance mutations in bio-banked plasma samples 6–12 months after initiation of a protease inhibitor-based treatment regimen. Additionally, viral load was measured before start of protease inhibitor, a second time between 1–5 years after start, and at suspected treatment failure in patients with available bio-banked samples. We performed resistance testing if viral load was ≥1000 copies/ml. Risk factors for virologic failure were analyzed using logistic regression.ResultsIn total, 252 patients were included; of those 56% were female and 21% children. Virologic failure occurred 6–12 months after the start of a protease inhibitor in 26/199 (13.1%) of adults and 7/53 of children (13.2%). The prevalence of virologic failure did not change over time. Nucleoside reverse transcriptase inhibitors drug resistance mutation testing performed at 6–12 months showed a positive signal in only 9/16 adults. No cases of resistance mutations for protease inhibitors were seen at this time. In samples taken between 1–5 years protease inhibitor resistance was demonstrated in 2/7 adults. In adult samples before protease inhibitor start, resistance to nucleoside reverse transcriptase inhibitors was detected in 30/41, and to non-nucleoside reverse-transcriptase inhibitors in 35/41 patients. In 15/16 pediatric samples, resistance to both drug classes but not for protease inhibitors was present.ConclusionOur study confirms high early failure rates in adults and children treated with protease inhibitors, even in the absence of protease inhibitors resistance mutations, suggesting an urgent need for adherence support in this setting.

Characterisation of protease resistance mutations in a South African paediatric cohort with virological failure, 2011 - 2017.

Advances in HIV management have improved treatment outcomes in the HIV-infected population. However, these advances have not been without multifaceted challenges. In sub-Saharan Africa, their impact is reflected in the increased emergence of HIV drug resistance mutations. With the rise in exposure of children to protease inhibitors (PIs), the possibility of increasing PI resistance remains a concern. To describe a group of antiretroviral-experienced children with PI drug resistance mutations after failure on first- or second-line regimens in a public sector setting in South Africa. This was a retrospective cohort study of 22 children perinatally infected with HIV who had HIV genotyping conducted between January 2011 and December 2017. Of the 236 children who had HIV genotyping conducted, 22 (9.3%) had evidence of HIV PI resistance mutations. Twenty-one of the 22 children (95.5%) had major mutations in the protease region of the HIV genome. Of these children, 66.7% (14/21) had loss of response to both boosted lopinavir and atazanavir, with boosted darunavir remaining susceptible in only 12 (57.1%). The most frequent major PI mutations were V82A (76.2%), M46I/M46L (76.2%), I54V (62.0%) and L76V (33.3%). We observed a high rate of PI resistance mutations, with a resulting loss of PIs that could be used in construction of third-line regimens. To build on improvements from the introduction of antiretroviral therapy, increased efforts are needed by both health professionals and caregivers to improve adherence measures in children perinatally infected with HIV.

Near-Neighbor Interactions in the NS3-4A Protease of HCV Impact Replicative Fitness of Drug-Resistant Viral Variants

A variety of amino acid substitutions in the NS3-4A protease of the hepatitis C virus lead to protease inhibitor (PI) resistance. Many of these significantly impair the replication fitness of the resistant variants in a genotype- and subtype-dependent manner, a critical factor in determining the probability with which resistant variants will persist. However, the underlying molecular mechanisms are unknown. Here, we present a novel residue-interaction network approach to determine how near-neighbor interactions of PI resistance mutations in NS3-4A can impact protease functional sites dependent on their genomic background. We constructed subtype-specific consensus residue networks for subtypes 1a and 1b from protease structure ensembles combined with biological properties of protein residues and evolutionary amino acid conservation. By applying local and global network topology analysis and visual exploration, we characterize PI resistance-associated sites and outline differences in near-neighbor interactions. We find local residue-interaction patterns and features at protease functional sites that are subtype specific. The noncovalent bonding patterns indicate higher fitness costs conferred by PI resistance mutations in a subtype 1b genomic background and explain the prevalence of Q80K and R155K in subtype 1a. Based on local residue interactions, we predict a subtype-specific role for the protease residue NS3–Q80 in molecular mechanisms related to the assembly of infectious virus particles that is supported by experimental data on the capacity of Q80K variants to replicate and produce infectious virus in subtype 1a and 1b cell culture.

Low Frequency of Protease Inhibitor Resistance Mutations and Insertions in HIV-1 Subtype C Protease Inhibitor-Naïve Sequences.

Human immunodeficiency virus-1 (HIV-1) protease sequences from 2,225 protease inhibitor (PI)-naïve HIV-1 subtype C-infected individuals collected over a 14-year period were analyzed for polymorphisms. Over 50% of sequences differed from an HIV-1 subtype B consensus sequence at 8 of the 99 amino acids at residues 12, 15, 19, 36, 41, 69, 89, and 93, but not in the functionally important regions. The frequency of primary resistance and accessory mutations occurred in <1% of the sequences. Of note, 11 sequences (0.5%) harbored amino acid insertions between residues 36 and 39, located in the elbow of the flap region. The insertions were found throughout the 13-year period. Occurrence of insertions in subtype C viruses is rare and viruses remain sensitive to currently used PIs (lopinavir/r, atazanavir/r, and darunavir/r). However, ongoing characterization of isolates is required to identify changes that may impact PI treatment since PIs are part of standard SA regimens.

A Clinical Prediction Rule for Protease Inhibitor Resistance in Patients Failing Second-Line Antiretroviral Therapy.

Background:Most adults with virological failure on second-line antiretroviral therapy (ART) in resource-limited settings have no major protease inhibitor (PI) resistance mutations. Therefore, empiric switches to third-line ART would waste resources. Genotypic antiretroviral resistance testing (GART) is expensive and has limited availability. A clinical prediction rule (CPR) for PI resistance could rationalize access to GART.Setting:A private sector ART cohort, South Africa.Methods:We identified adults with virologic failure on ritonavirboosted lopinavir/atazanavir-based ART and GART. We constructed a multivariate logistic regression model including age, sex, PI duration, short-term adherence (using pharmacy claims), concomitant CYP3A4-inducing drugs, and viral load at time of GART. We selected variables for the CPR using a stepwise approach and internally validated the model by bootstrapping.Results:148/339 (44%) patients had PI resistance (defined as ≥ 1 major resistance mutation to current PI). The median age was 42 years (interquartile range 36–48), 212 (63%) were females, 308 (91%) were on lopinavir/ritonavir, and median PI duration was 2.6 years (interquartile range 1.6–4.7). Variables associated with PI resistance and included in the CPR were age {adjusted odds ratio (aOR) 1.96 (95% confidence interval [CI]: 1.42 to 2.70) for 10-year increase}, PI duration (aOR 1.14 [95% CI: 1.03 to 1.26] per year), and adherence (aOR 1.22 [95% CI: 1.12 to 1.33] per 10% increase). The CPR model had a c-statistic of 0.738 (95% CI: 0.686 to 0.791).Conclusions:Older patients with high adherence and prolonged PI exposure are most likely to benefit from GART to guide selection of a third-line ART regimen. Our CPR to select patients for GART requires external validation before implementation.

HIV-1 Drug Resistance Mutations among Antiretroviral Drug-Experienced Patients in the South of Iran

Background: The therapeutic effect of antiretroviral therapy (ART) is adversely influenced by antiretroviral drug resistance, mainly due to mutations (DRMs) in the human immunodeficiency virus (HIV) genome. These mutations are commonly associated with HIV protease and reverse-transcriptase genes. We sought to determine the frequency of DRMs in a population of ART-experienced patients in the South of Iran. Method: A total of 44 HIV-1-positive participants under ART were selected from April 2016 to March 2017. Their DRMs, antiretroviral resistance status, and viral subtypes were determined. Results: At least one DRM was detected in 61.4% of the participants. The highest frequency was related to nucleotide reverse-transcriptase inhibitor (NRTI) mutations (45.45%). In contrast, major protease inhibitor (PI) mutations had the lowest frequency (6.81%). M184V (40.9%) and K103N (25%), respectively related to NRTI and nonnucleoside reverse-transcriptase inhibitor (NNRTI), were the mutations with the highest frequencies. Susceptibility to PI drugs was higher compared to NRTIs and NNRTIs, which was consistent with the results of genotypic DRMs. Conclusion: The highest frequency of antiretroviral DRMs was related to NRTIs and NNRTIs. In contrast, PI resistance mutations had the lowest frequency. Laboratory-guided ART to avoid the expansion of mutants as well as investigating DRMs in other viral regions, such as integrase, are recommended.

Research on the treatment effects and drug resistances of long-term second-line antiretroviral therapy among HIV-infected patients from Henan Province in China

BackgroundHIV/AIDS patients who fail to respond to first-line treatment protocols are switched to second-line ART. Identifying factors that influence effective second-line treatment can improve utilization of limited medical resources. We investigated the efficacy of long-term second-line anti-retroviral therapy (ART) after first-line virologic failure as well as the impact of non-nucleotide reverse transcriptase inhibitor (NNRTI), nucleotide reverse transcriptase inhibitor (NRTI), and protease inhibitor (PI) resistance mutations and medication adherence on ineffective viral suppression.MethodsA total of 120 patients were evaluated at 6, 12, 18, 24, and 48 months after initiation of second-line ART; a paper questionnaire was administered via a face-to-face interview and venous blood samples were collected. CD4+ T cell count, viral load, and drug resistance genotypes were quantified.ResultsCD4+ T cell counts increased from 170 cells/μL (IQR 100–272) at baseline to 359 cells/μL (IQR 236–501) after 48 months of second-line treatment. Viral load (log10) decreased from 4.58 copies/mL (IQR 3.96–5.17) to 1.00 copies/mL (IQR 1.00–3.15). After switching to second-line ART, nine patients newly acquired the NRTI drug-resistant mutation, M184 V/I. No major PI resistance mutations were detected. Logistical regression analysis indicated that medication adherence < 90% in the previous month was associated with ineffective viral suppression; baseline high/low/moderate level resistance to 3TC/TDF was protective towards effective viral suppression.ConclusionsLong-term second line ART was effective in the Henan region of China. Drug resistance mutations to NRTIs were detected in patients receiving second-line ART, suggesting that drug resistance surveillance should be continued to prevent the spread of resistant strains. Patient medication adherence supervision and management should be strengthened to improve the efficacy of antiviral treatment.

HIV-1 Drug Resistance Profiles for the HIV Protease and Reverse Transcriptase Gene in Patients Receiving Combination Therapy in Tehran, Iran.

Determination of the drug-resistant mutations has a crucial role in the management of HIV-1 infected patients. The aim of the current study was to evaluate drug resistance profile of Reverse transcriptase and Proteasegenes, and to find the correlation between drug resistance mutations and ART regimen to intensifyphysicians'options for the most effective therapy which could also influence the establishment of health-related policies at the national level in Iran. HIV-1 RNA of 34 samples was extracted from plasma and RT Nested- PCR was performed and the final products were sequenced. Stanford HIV drug resistance sequence database was used for interpretation of the data. In 14 patients out of 15, the following mutations were observed; Nucleoside RT Inhibitor (NRTI)-Resistance Mutations with the prevalence of 11 patients having this mutation at codon 184 (73%) and Non-Nucleoside RT Inhibitor (NNRTI)-Resistance Mutations with the prevalence of 8 patients having NNRTI mutations at codon 103(53%).In 17 patients, major Protease Inhibitor (PI) Resistance Mutations were found out in 2 (12%) of them while the minor PI was found in7 (41%) patients. An antiretroviral treatment consisting of nucleoside reverse transcriptase inhibitor, non-nucleoside reverse transcriptase inhibitor and protease inhibitor, impairs the emergence of a resistant strain and descends its prevalence among the community. Having a high rate mutation in participants of this study raises concerns about treatment failure in HIV infected people in Iran. Observing high mutations rates in participants of this study raises concerns about treatment failure in HIV infected people in Iran.

HIV-1 Drug Resistance and Third-Line Therapy Outcomes in Patients Failing Second-Line Therapy in Zimbabwe.

ObjectivesTo analyze the patterns and risk factors of HIV drug resistance mutations among patients failing second-line treatment and to describe early treatment responses to recommended third-line antiretroviral therapy (ART) in a national referral HIV clinic in Zimbabwe.MethodsPatients on boosted protease inhibitor (PI) regimens for more than 6 months with treatment failure confirmed by 2 viral load (VL) tests >1000 copies/mL were genotyped, and susceptibility to available antiretroviral drugs was estimated by the Stanford HIVdb program. Risk factors for major PI resistance were assessed by logistic regression. Third-line treatment was provided as Darunavir/r, Raltegravir, or Dolutegravir and Zidovudine, Abacavir Lamivudine, or Tenofovir.ResultsGenotypes were performed on 86 patients who had good adherence to treatment. The median duration of first- and second-line ART was 3.8 years (interquartile range [IQR], 2.3–5.1) and 2.6 years (IQR, 1.6–4.9), respectively. The median HIV viral load and CD4 cell count were 65 210 copies/mL (IQR, 8728–208 920 copies/mL) and 201 cells/mm3 (IQR, 49–333 cells/mm3). Major PI resistance-associated mutations (RAMs) were demonstrated in 44 (51%) non-nucleoside reverse transcriptase inhibitor RAMs in 72 patients (83%) and nucleoside reverse transcriptase inhibitors RAMs in 62 patients (72%). PI resistance was associated with age >24 years (P = .003) and CD4 cell count <200 cells/mm3 (P = .007). In multivariable analysis, only age >24 years was significantly associated (adjusted odds ratio, 4.75; 95% confidence interval, 1.69–13.38; P = .003) with major PI mutations. Third-line DRV/r- and InSTI-based therapy achieved virologic suppression in 29/36 patients (81%) after 6 months.ConclusionsThe prevelance of PI mutations was high. Adolescents and young adults had a lower risk of acquiring major PI resistance mutations, possibly due to poor adherence to ART. Third-line treatment with a regimen of Darunavir/r, Raltegravir/Dolutegravir, and optimized nucleoside reverse transcriptase inhibitors was effective.

Characteristics of Treatment-experienced HIV-infected African Children and Adolescents Initiating Darunavir and/or Etravirine-based Antiretroviral Treatment.

Data are limited on the selection and sequencing of second-line and third-line pediatric antiretroviral treatment (ART) in resource-limited settings. This study aimed to evaluate characteristics of African pediatric patients initiated on darunavir (DRV) and/or etravirine (ETR) through a specific drug donation program. This was a cross-sectional study of baseline immunologic, virologic and demographic characteristics of children and adolescents initiating DRV-based and/or ETR-based ART. Descriptive statistics were used. Study enrolled 48 patients (45.8% women; median age = 15 years [interquartile range 17.7-10.3]) at 9 clinical sites in Zambia, Swaziland, Kenya and Lesotho. The majority (87.5%; n = 42) had received ≥2 prior ART regimens; most (81.2%) had received lopinavir/ritonavir-based ART before switch. All patients had detectable HIV RNA (median = 56,653 copies/mL). Forty seven patients (98.9%) had HIV genotype results: 41 (87.2%) had ≥1 nucleos(t)ide reverse transcriptase inhibitor (NRTI)-resistance mutation (RM), predominantly M184V (76.6%; n = 36); 31 (65.9%) had ≥1 non-NRTI-RM, including 27 (57.4%) with ≥1 ETR-RM; 30 (63.8%) had ≥3 protease inhibitor RM, including 20 (42.6%) with ≥1 DRV-RM. For new ART regimens, DRV and raltegravir were most frequently prescribed (83.3%; n = 40 on DRV and raltegravir, each). Eighteen patients (37.5%) were initiated on the NRTI-sparing ART. In our study, a significant proportion of treatment-experienced African children and adolescents had one or more DRV-RM and ETR-RM. For the new regimen, more than a third of pediatric patients failing second-line ART were prescribed NRTI-sparing regimens. Better understanding of the current approaches to pediatric ART sequencing in resource-limited settings is needed.

Drug resistance mutations and its associated factors among 579 HIV/AIDS patients experiencing failure of antiretroviral therapy in Jiangsu Province, China

Objective: To understand the incidence and related factors of HIV-1 drug resistance among HIV/AIDS patients experiencing treatment failure in Jiangsu province, China. Methods: The HIV/AIDS integrated prevention and control data information management system of China were used to collect the basic data of patients, blood specimens were collected from patients who had antiretroviral therapy (ART) failure with ≥12 months and older than 18 years in 2016 in Jiangsu, excluding cases with missing information, 713 cases were enrolled in this study. HIV-1 RNA was extracted, and then pol gene region was amplified and sequenced. The obtain sequences were submitted to Stanford University HIV Drug Resistance Database to interpret and analyse HIV-1 drug resistance and sub-types. Multivariate logistic regression model was used to explore the related factors of drug resistance. Results: A total of 579 subjects were amplified successfully, male accounted for 85.66% (496 cases), and the median age was 39 years old. The main route of infection was sexual transmission (553 cases, 95.51%). A total of 331 patients with drug resistance gene mutation were detected, drug resistance mutation rate was 57.18%. Compared with patients with baseline CD4(+)T cell count >500 cells/μl, patients with CD4(+)T cell count in 201-500 cells/mm(3) and ≤200 cells/μl had a higher incidence of genetic drug resistance, the odds ratio was 3.33 and 6.87, respectively. Compared with patients with treatment less than 24 months, patients treated for 25-48 months had a higher incidence of drug resistance, the odds ratio was 1.88. Compared with patients infected by CRF07_BC strains, patients infected by CRF01_AE strains were associated with higher incidence of drug resistance, the odds ratio was 2.22 and 3.32, respectively. Protease inhibitor (PI) resistance mutations, nucleoside reverse transcriptase inhibitor (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) were found in 3.80%, 33.16% and 53.37% of patients, respectively. 31.95% of patients harbored NRTI and NNRTI resistance mutations simultaneously. M184V/I and K103N/Q were the highest frequency of NRTI and NNRTI resistance mutation, the prevalence of M184V/I and K103N/Q were 28.15% and 22.28%, respectively. Conclusion: The status of HIV-1 drug resistance mutations are complex and diverse among patients experiencing failure of ART in Jiangsu. Patients with lower baseline CD4(+)T cell count, longer treatment time and HIV-1 CRF01_AE and B strains infection were associated with higher incidence of drug resistance mutation.

Prevalence of HIV-1 pre-treatment drug resistance in a southern province of Iran, 2016-2017.

HIV-1 transmitted drug resistance (TDR) occurs when primary viruses bear drug resistance mutations (DRMs). TDR causes first-line antiretroviral (ARV) therapy (ART) failure and is becoming more pronounced due to the widespread use of ART. With the absence of routine individual-level drug resistance testing, the World Health Organization (WHO) recommends the tracking of TDR mutations and optimizing the first-line ART following pre-treatment drug resistance (PDR) surveys. Here, we report the PDR frequency for the first time in Hormozgan, a southern province of Iran. In this study, 41 blood samples from HIV-1-positive ART-candidate volunteers were collected across the province between April 2016 and March 2017. Phylogenetic analysis of the sequenced protease (PR) and reverse transcriptase (RT) regions showed that 39 out of 41 samples (95%) were CRF35_AD and the two remaining cases were subtype B (2.5%) and C (2.5%). D67G (2.4%), a mutation that reduces susceptibility to nucleoside reverse transcriptase inhibitors (NRTIs) was the only detectable TDR mutation in this population. Two other DRMs, including E138A (9.7%) and V179T (4.9%), which confer resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs), were also identified. Although no major protease inhibitor (PI) resistance mutations were detected, the minor mutations L10F and L33F (2.5% each) as well as several highly frequent polymorphic mutations were identified. Our results show a PDR frequency of 17% in infected individuals from Hormozgan, classified further as 2.4% NRTIs and 14.6% NNRTIs. These results suggest that first-line ART should be practiced carefully in Hormozgan province, and alternative regimens may become necessary for all starters.

Antiretroviral resistance following immunological monitoring in a resource-limited setting of western India: A cross-sectional study.

BackgroundThe free antiretroviral therapy (ART) program in India still relies on the clinico-immunological monitoring for diagnosis of treatment failure. As the nucleoside reverse transcriptase inhibitor (NRTI) backbone is shared in first- and second-line regimens, accumulation of drug resistant mutations (DRMs) can compromise the efficacy of NRTI. This study was undertaken to describe the pattern of HIV DRMs following immunological monitoring and investigate its impact on the cycling of NRTI between first- and second-line ART.Methods and findingsThis cross-sectional study was performed at a state-sponsored ART clinic of Pune city in western India between January and June 2016. Consecutive adults receiving first-line ART with immunological failure (IF) were recruited for plasma viral load (PVL) estimation. Randomly selected 80 participants with PVL >1000 copies/mL underwent HIV drug resistance genotyping. Of these, 75 plasma sample were successfully genotyped. The median CD4 count and duration of ART at the time of failure were 98 (IQR: 61.60–153.50) cells/μL and 4.62 (IQR: 3.17–6.15) years, respectively. The prevalence of NRTI, non-NRTI, and major protease inhibitor resistance mutations were 89.30%, 96%, and 1.33%, respectively. Following first-line failure, sequences from 56.67% of individuals indicated low- to high-level resistance to all available NRTI. The proportion of sequences with ≥2 thymidine analogue mutations (TAMs) and ≥3 TAMs were 62.12% and 39.39%, respectively. An average of 1.98 TAMs per sequence were observed following IF as compared to 0.37 TAMs per sequence following targeted PVL monitoring at 12 months of ART from a prior study; this difference was significant (p<0.001).ConclusionThe option of cycling of NRTI analogues between first- and second-line regimens would no longer be effective if individuals are followed-up by immunological monitoring due to accumulation of mutations. Introduction of routine PVL monitoring is a priority for the long-term sustainability of free ART program in India.