HIV-1 Integrase T218I/S Polymorphisms Do Not Reduce HIV-1 Integrase Inhibitors' Phenotypic Susceptibility.

The recently Food and Drug Administration (FDA)-approved cabotegravir (CAB) has demonstrated efficacy as an antiretroviral agent for HIV treatment and prevention, becoming an important tool to stop the epidemic in the United States of America (USA). However, the effectiveness of CAB can be compromised by the presence of specific integrase natural polymorphisms, including T97A, L74M, M50I, S119P, and E157Q, particularly when coupled with the primary drug-resistance mutations G140S and Q148H. CAB's recent approval as a pre-exposure prophylaxis (PrEP) may increase the number of individuals taking CAB, which, at the same time, could increase the number of epidemiological implications. In this context, where resistance mutations, natural polymorphisms, and the lack of drug-susceptibility studies prevail, it becomes imperative to comprehensively investigate concerns related to the use of CAB. We used molecular and cell-based assays to assess the impact of T218I and T218S in the context of major resistance mutations G140S/Q148H on infectivity, integration, and resistance to CAB. Our findings revealed that T218I and T218S, either individually or in combination with G140S/Q148H, did not significantly affect infectivity, integration, or resistance to CAB. Notably, these polymorphisms also exhibited neutrality concerning other widely used integrase inhibitors, namely raltegravir, elvitegravir, and dolutegravir. Thus, our study suggests that the T218I and T218S natural polymorphisms are unlikely to undermine the effectiveness of CAB as a treatment and PrEP strategy.

Reversibility of Neuropsychiatric Adverse Events after Switching to Darunavir/Cobicistat or Doravirine in Men on INSTI-Based Regimen.

Integrase strand transfer inhibitors (INSTI) are associated with neuropsychiatric adverse events (NPAEs). The aim of this study was to evaluate improvements in NPAEs after switching an INSTI-based regimen to darunavir/cobicistat (DRV/c) or doravirine (DOR). Methods: A prospective cohort study was conducted to evaluate the reversibility of NPAEs via the Patient Health Questionnaire (PHQ-9), the Insomnia Severity Index (ISI), and the Hospital Anxiety and Depression Scale (HADS-A and D) in patients who started antiretroviral therapy with dolutegravir (DTG) or bictegravir (BIC). These patients were switched to DRV/c or DOR. Scales were compared at the moment of the switch and 12 weeks later. Results: We included 1153 treatment-naïve men, 676 (58.7%) with BIC and 477 (41.3%) with DTG. A total of 32 (2.7%) experienced NPAEs that led to discontinuation. Insomnia was found in 20 patients; depression via PHQ-9 in 21 patients, via HADS-D in 5 patients, and anxiety via HADS-A in 12 patients. All of them were evaluated by a psychiatrist at the moment of the symptoms; 7 (21.8%) started psychotropic drugs. After 12 weeks of follow-up, PHQ-9, ISI, HADS-A, and HADS-D decreased, with a p-value ≤ 0.05. Conclusions: NPAEs seem to improve after switching to a DRV/c- or DOR-based regimen after the first 4 and 12 weeks.

Comparison of Four Predictive Scores for Cardiovascular Risk in Mexican People with HIV.

Persons with HIV (PWH) face an increased risk of cardiovascular events due to immune activation, comorbidities, and certain antiretrovirals (ARVs). However, the current cardiovascular risk (CVR) scores are not specifically directed toward PWH. This study aimed to assess the agreement between different predictive CVR scores and explore their relationship with clinical and demographic data in Mexican PWH. A descriptive cross-sectional analysis was conducted in 200 PWH with a mean age of 42 years who were treated at a Mexican urban center from 2017 to 2018. The majority (83%) was on ARV treatment and 79.5% had undetectable viral loads (VLs). Moderate- to high-risk scores were infrequent, with Framingham Risk Score for Hard Coronary Heart Disease scores showing higher values, with very low concordance among all scores. Logistic regression analysis revealed significant associations between the CVR scores and the initial recorded VL, CD4 cell count, and elevated triglyceride levels. However, no associations were found with measures such as body mass index or abdominal circumference. Treatment with integrase strand transfer inhibitors (INSTIs), particularly first-generation inhibitors, showed strong associations with all predictive scores, notably ASCVD (odds ratio = 7.03, 95% confidence interval 1.67-29.64). The poor concordance among the CVR scores in PWH highlights the need for a specific score that considers comorbidities and ARV drugs. Despite the relatively young age of the participants, significant correlations were observed between INSTI use, initial VL, CD4 cell count, and triglyceride levels, which are factors not considered in the existing risk scores. Regardless of the actual value of the scores, screening for CVR in PWH is recommended.

Heterogeneities of the impact of public health policies on HIV/AIDS indicators in Brazil according to sociodemographic factors: A real-life study.

INTRODUCTION: The impact of specific policies on HIV care has been scarcely investigated. In this study we aimed to analyze the impact of the Treatment For All policy (TFA-2013) and the adoption of integrase strand transfer inhibitors (INSTIs-2017) as first-line therapy on clinical indicators of people living with HIV (PLHIV) in Brazil. METHODS: We assessed the public database of Brazil's Ministry of Health and extracted data from 2009 to 2019. We investigated the impact of TFA and INSTIs with a time-series analysis of four health indicators in PLHIV: antiretroviral treatment (ART) initiation with a CD4+ count >500/mm3 ; ART initiation <1 month after the first CD4+ measurement; viral load suppression (VLS); and treatment adherence. We explored trends over time by gender, age, macroregion of residency and municipal-level social vulnerability index. RESULTS: We included 753 316 PLHIV in 2019. Most were males (64.81%) in the 30-49 years age category (50.86%). We observed an overall improvement in all HIV clinical indicators, with notable impact of TFA on timely ART initiation and VLS, and mild impact of INSTIs on treatment adherence. Such improvements were heterogeneous, with remarkable gaps in gender, age and socioeconomic groups that have persisted over time. Indicators point to inferior outcomes among children, older adults, women and people living in socially vulnerable locations. CONCLUSIONS: Recent Brazilian public policies have had positive impacts on key HIV clinical indicators. However, our results highlight the need for specific policies to improve HIV care for children, older adults, women and socially vulnerable groups.

Development of H51Y and E157Q mutations for integrase inhibitor resistance in a patient undergoing treatment for pulmonary tuberculosis: A case report.

Background: Failure of first-line regimens with dolutegravir, a high genetic barrier antiretroviral of the integrase inhibitor class, although uncommon, tends to increase in prevalence due to broader use. Objective: To describe the clinical case of an HIV/Tuberculosis coinfected patient who developed Human Immunodeficieny Virus (HIV) treatment failure during dolutegravir therapy. Case report: Male, 29 years old, presented with a right cervical mass, dry cough, and hyporexia, which lasted 2 weeks. Diagnostic tests were positive for tuberculosis and HIV. The viral load was 437,927 cp/mL (Log = 5.64). Antiretroviral therapy was initiated with Tenofovir/Lamivudine and Dolutegravir (TDF/3TC and DTG), the latter at a dose of 50 mg/day, as was a regimen for tuberculosis. After 8 months, therapeutic failure was verified. Genotyping was requested, with detection of the H51Y and E157Q mutations in the integrase. Conclusion: Attention when determining the antiretroviral therapy treatment regimen of HIV/TB coinfected patients is paramount. Poor adherence to antiretroviral therapy and follow-up may have contributed to treatment failure and resistance.

Signal Amplification for Cell-Free Biosensors, an Analog-to-Digital Converter.

Toehold switches are biosensors useful for the detection of endogenous and environmental RNAs. They have been successfully engineered to detect virus RNAs in cell-free gene expression reactions. Their inherent sequence programmability makes engineering a fast and predictable process. Despite improvements in the design, toehold switches suffer from leaky translation in the OFF state, which compromises the fold change and sensitivity of the biosensor. To address this, we constructed and tested signal amplification circuits for three toehold switches triggered by Dengue and SARS-CoV-2 RNAs and an artificial RNA. The serine integrase circuit efficiently contained leakage, boosted the expression fold change from OFF to ON, and decreased the detection limit of the switches by 3-4 orders of magnitude. Ultimately, the integrase circuit converted the analog switches' signals into digital-like output. The circuit is broadly useful for biosensors and eliminates the hard work of designing and testing multiple switches to find the best possible performer.

A Class 4-like Chromosomal Integron Found in Aeromonas sp. Genomospecies paramedia Isolated from Human Feces.

Integrons are genetic elements that store, express and exchange gene cassettes. These elements are characterized by containing a gene that codes for an integrase (intI), a cassette integration site (attI) and a variable region holding the cassettes. Using bioinformatics and molecular biology methods, a functional integron found in Aeromonas sp. 3925, a strain isolated from diarrheal stools, is described. To confirm the integron class, a phylogenetic analysis with amino acid sequences was conducted. The integrase was associated to class 4 integrases; however, it is clearly different from them. Thus, we classified the associated element as a class 4-like integron. We found that the integrase activity is not under the control of the SOS or catabolic repression, since the expression was not increased in the presence of mitomycin or arabinose. The class-4-like integron is located on the chromosome and contains two well-defined gene cassettes: aadA1 that confers resistance to streptomycin and lpt coding for a lipoprotein. It also includes eight Open Reading frames (ORFs) with unknown functions. The strain was characterized through a Multilocus Phylogenetic Analyses (MLPA) of the gyrB, gyrA, rpoD, recA, dnaJ and dnaX genes. The phylogenetic results grouped it into a different clade from the species already reported, making it impossible to assign a species. We resorted to undertaking complete genome sequencing and a phylogenomic analysis. Aeromonas sp. 3925 is related to A. media and A. rivipollensis clusters, but it is clearly different from these species. In silico DNA-DNA hybridization (isDDH) and Average Nucleotide Identity (ANI) analyses suggested that this isolate belongs to the genomospecies paramedia. This paper describes the first class 4-like integron in Aeromonas and contributes to the establishment of genomospecies paramedia.

Integrase inhibitors: current protagonists in antiretroviral therapy.

Since HIV was identified as the etiological agent of AIDS, there have been significant advances in antiretroviral therapy (ART) that has reduced morbidity/mortality. Still, the viral genome's high mutation rate, suboptimal ART regimens, incomplete adherence to therapy and poor control of the viral load generate variants resistant to multiple drugs. Licensing over 30 anti-HIV drugs worldwide, including integrase inhibitors, has marked a milestone since they are potent and well-tolerated drugs. In addition, they favor a faster recovery of CD4+ T cells. They also increase the diversity profile of the gut microbiota and reduce inflammatory markers. All of these highlight the importance of including them in different ART regimens.

Research on HIV/AIDS has been focused on finding ways to prevent or cure the disease. One important class of drugs called integrase inhibitors has gained attention. These drugs are effective and have been widely used in the past decade to treat HIV. Integrase inhibitors help in the recovery of immune cells and improve the diversity of gut bacteria while reducing inflammation. It is important to include these drugs in treatment regimens for people living with HIV.

Weight and Metabolic Outcomes in Naïve HIV Patients Treated with Integrase Inhibitor-Based Antiretroviral Therapy: A Systematic Review and Meta-Analysis.

BACKGROUND: The use of integrase inhibitor-based antiretroviral therapy could be associated with worse weight and metabolic outcomes in patients with HIV infection. METHODS: PubMed, EMBASE, and Scopus were searched from inception to March 2022. We selected randomized controlled trials (RCTs) comparing integrase inhibitors with other antiretroviral classes (efavirenz-based or protease inhibitor-based therapies) in naïve HIV patients. Random effects meta-analysis was used to assess the effects of integrase inhibitors vs. controls on weight and lipid outcomes. Effects were described as mean differences (MD) and their 95% confidence intervals (CI). Certain pieces of evidence (CoE) were evaluated using the GRADE methodology. RESULTS: Six RCTs (n = 3521) were included, with patients followed up between 48 and 96 weeks. The use of integrase inhibitors in comparison with other antiretroviral classes was associated with an increase in weight (MD 2.15 kg, 95%CI 1.40 to 2.90, I2 = 0%, moderate CoE), and decreases in total cholesterol (MD -13.44 mg/dL, 95%CI -23.49 to -3.39, I2 = 96%, low CoE), LDL cholesterol (MD -1.37 mg/dL, 95%CI -19.24 to -3.50, I2 = 83%, low CoE), HDL cholesterol (MD -5.03 mg/dL, 95%CI -10.61 to 0.54, I2 = 95%, low CoE), and triglycerides (MD -20.70 mg/dL, 95%CI -37.25 to -4.15, I2 = 92%, low CoE). There was a high risk of bias in two RCTs and some concerns about bias in two RCTs. CONCLUSIONS: In HIV patients, the use of integrase inhibitor-based therapy in comparison with protease inhibitor- or NNRTI-based therapy was associated with a small increase in weight and small decreases in lipid serum levels.

Real-world experience with weight gain among pregnant women living with HIV who are using integrase inhibitors.

OBJECTIVES: We assessed real-world weight change and pregnancy outcomes among pregnant women living with HIV who used integrase strand transferase inhibitor (INSTI)-based combined antiretroviral therapy (cART). METHODS: In a retrospective cohort study from 2014 to 2021 for prevention of perinatal HIV infection, we evaluated changes in weight from the first prenatal visit to near delivery for two groups. The categories of change were: low (< 0.18 kg/week), normal (0.18-0.59 kg/week), and high (> 0.59 kg/week). The backbones were lamivudine + tenofovir disoproxil or lamivudine + zidovudine. The comparison groups were women with body mass index (BMI) < 25 kg/m2 versus BMI ≥ 25 kg/m2 and INSTI-naïve versus INSTI-experienced. Continuous variables were analysed with a Kruskal-Wallis test and count or categorical data with χ2 tests. RESULTS: We enrolled 198 pregnant women. At study entry, 74 had BMI < 25 kg/m2 and 124 had BMI ≥ 25 kg/m2 . Excess gestational weight gain was more frequent among women who were INSTI-naïve among both BMI groups (< 25 and ≥ 25). However, the proportion of participants per weight change category was only significantly different between INSTI-naïve women with baseline BMI < 25 kg/m2 and INSTI-experienced women with BMI < 25 kg/m2 . In particular, INSTI-naïve women with BMI < 25 kg/m2 had significantly higher rates of excess gestational weight gain (31.6%) compared with participants with BMI < 25 kg/m2 who conceived while on INSTIs (11.8%, p = 0.004). Rates of unfavourable pregnancy outcomes were low and did not differ significantly between groups. CONCLUSIONS: INSTI-naïve participants with BMI < 25 kg/m2 gained more weight during pregnancy than participants with BMI ≥ 25 kg/m2 who conceived while using INSTIs. Rates of adverse pregnancy outcomes did not differ between the groups.

Undetectable proviral DNA and viral RNA levels after raltegravir administration in two cats with natural feline leukemia virus infection.

Feline leukemia virus (FeLV) infection was discovered over 50 years ago; however, the serious clinical changes associated with FeLV infection still have great importance in the diagnosis, prevention, and clinical management of symptomatic patients. Progressive infection with FeLV leads to a reduction in the patient's life expectancy and quality of life. This report describes the use of an antiretroviral integrase inhibitor, raltegravir, in two cats with natural FeLV infection. Raltegravir was administered orally at a dose of 40 mg/cat every 12 h in both cases. In case one, 13 weeks after starting raltegravir, RNA loads were undetectable, while proviral DNA loads were still detectable. In case two, proviral DNA loads were undetectable after 32 weeks of medication, while RNA loads were undetectable throughout the treatment. No adverse effects or laboratory test abnormalities were detected with the use of raltegravir in either patient. The patients are currently clinically healthy, still receiving the drug, and are under close observation. To our knowledge, this is the first report describing the use of raltegravir in naturally infected FeLV-positive cats and its effects on circulating viral load. Moreover, the patients described here were followed-up for a longer period than those in previously reported cases.

A infecção pelo vírus da leucemia felina foi descoberta há mais de 50 anos, mas as graves alterações clínicas associadas à infecção pelo FeLV, ainda denotam grande importância no diagnóstico, nas medidas de prevenção e no manejo clínico de pacientes sintomáticos. A infecção progressiva pelo FeLV acarreta na redução do tempo e qualidade de vida do paciente. Este relato descreve o uso de um antirretroviral inibidor da integrase, o raltegravir, em dois gatos com infecção natural pelo FeLV. O raltegravir foi utilizado na dose de 40 mg/gato por via oral a cada 12 horas em ambos os casos. No primeiro caso após treze semanas do uso do raltegravir, a quantificação de RNA foi indetectável e no segundo caso, após trinta e duas semanas o número de cópias de DNA pró-viral foi indetectável. A carga de RNA nunca foi detectada neste paciente. Nenhum efeito adverso, nem alterações laboratoriais foram detectadas com o uso do raltegravir em ambos os casos. Atualmente, os pacientes encontram-se clinicamente saudáveis, fazem uso do antiretroviral com monitorização contínua. Este é o primeiro relato que descreve o uso do raltegravir em gatos infectados naturalmente pelo FeLV e seus efeitos na carga viral circulante. Além disso, os pacientes descritos aqui foram acompanhados por um período maior que os trabalhos anteriores descritos.

Novel Mobile Integrons and Strain-Specific Integrase Genes within Shewanella spp. Unveil Multiple Lateral Genetic Transfer Events within The Genus.

Shewanella spp. are Gram-negative bacteria that thrive in aquatic niches and also can cause infectious diseases as opportunistic pathogens. Chromosomal (CI) and mobile integrons (MI) were previously described in some Shewanella isolates. Here, we evaluated the occurrence of integrase genes, the integron systems and their genetic surroundings in the genus. We identified 22 integrase gene types, 17 of which were newly described, showing traits of multiple events of lateral genetic transfer (LGT). Phylogenetic analysis showed that most of them were strain-specific, except for Shewanella algae, where SonIntIA-like may have co-evolved within the host as typical CIs. It is noteworthy that co-existence of up to five different integrase genes within a strain, as well as their wide dissemination to Alteromonadales, Vibrionales, Chromatiales, Oceanospirillales and Enterobacterales was observed. In addition, identification of two novel MIs suggests that continuous LGT events may have occurred resembling the behavior of class 1 integrons. The constant emergence of determinants associated to antimicrobial resistance worldwide, concomitantly with novel MIs in strains capable to harbor several types of integrons, may be an alarming threat for the recruitment of novel antimicrobial resistance gene cassettes in the genus Shewanella, with its consequent contribution towards multidrug resistance in clinical isolates.

Analysis of HIV-1 integrase genotypes and polymorphisms among integrase inhibitors-based antiretroviral treatment naïve patients in South Sudan.

HIV-1 genetic diversity and drug resistance mutations remain public health challenges especially in regions where treatment is limited. The aim of this study was to characterize the HIV-1 integrase (IN) subtype and the possible occurrence of drug-resistance mutations or polymorphisms in resource-poor settings in South Sudan. Dried blood spots from integrase inhibitor treatment (Integrase strand transfer inhibitor [INSTI]) naïve HIV-1 infected patients were subjected to DNA amplification and direct sequencing of integrase genes. The sequences were interpreted for drug resistance according to the Stanford algorithm and the International AIDS Society-USA guidelines. Phylogenetic analysis revealed that HIV-1 subtype D, C, G, A1, and recombinant forms accounted for 40%, 10%, 13.3%, 23.4%, and 13.3%, respectively. Furthermore, inter-subtype recombinants were interspersed within viral strains sampled in other African countries, highlighting complex transmission dynamics within a mobile host population. A total of 78 of 288 (27%) amino acid IN positions presented at least one polymorphism each. Major INSTI resistance mutations were absent, however, polymorphic accessory mutations at positions M50ILR (26.6%) and L74I (3.3%) were detected. Despite the limited size of the study population, our findings underscore the need for monitoring minor and natural polymorphisms that may influence the outcome of treatment regimens.

Pyrroles as Privileged Scaffolds in the Search for New Potential HIV Inhibitors.

Acquired immunodeficiency syndrome (AIDS) is caused by human immunodeficiency virus (HIV) and remains a global health problem four decades after the report of its first case. Despite success in viral load suppression and the increase in patient survival due to combined antiretroviral therapy (cART), the development of new drugs has become imperative due to strains that have become resistant to antiretrovirals. In this context, there has been a continuous search for new anti-HIV agents based on several chemical scaffolds, including nitrogenated heterocyclic pyrrole rings, which have been included in several compounds with antiretroviral activity. Thus, this review aims to describe pyrrole-based compounds with anti-HIV activity as a new potential treatment against AIDS, covering the period between 2015 and 2020. Our research allowed us to conclude that pyrrole derivatives are still worth exploring, as they may provide highly active compounds targeting different steps of the HIV-1 replication cycle and act with an innovative mechanism.

Perfil lipídico e inhibidores de integrasa: revisión sistemática y metaanálisis / Lipid profile and integrase inhibitors: a systematic review and metaanalysis

Resumen Introducción: en pacientes con virus de inmunodeficiencia humana algunos antirretrovirales afectan el perfil lipídico incrementando el riesgo cardiovascular. Hay evidencia de que los inhibidores de integrasa afectan poco al perfil lipídico. El presente estudio buscó evaluar la mejor evidencia disponible sobre cambios en lípidos de pacientes con virus de inmunodeficiencia humana que cambiaron su terapia antirretroviral a esquemas con inhibidores de integrasa. Métodos: revisión sistemática de la literatura con intención metaanalítica. A partir de la pregunta: "En pacientes mayores de 16 años con virus de inmunodeficiencia humana, los esquemas antirretrovirales que incluyen inhibidores de integrasa comparados con aquellos esquemas antirretrovirales que no los incluyen, ¿presentan cambios en el perfil lipídico?" se extrajeron palabras clave para búsqueda de la evidencia publicada entre 1997 y diciembre 2019. Se incluyeron estudios experimentales y observacionales y su calidad fue evaluada. Se realizó análisis por inhibidor de integrasa y parámetro lipídico buscándose síntesis cuantitativa de la evidencia. Resultados: se identificaron 17 estudios relevantes susceptibles de síntesis de la evidencia con un total de 5 683 pacientes. De estos, 2 878 entraron a síntesis cuantitativa. Acorde a lo encontrado, los inhibidores de integrasa presentan mejor perfil lipídico comparados a otros antirretrovirales. Dolutegravir fue el que mostró mejor perfil lipídico cuando la comparación se hizo con inhibidores de proteasa. Raltegravir tuvo mejor perfil lipídico comparándolo con inhibidores de transcriptasa inversa no análogos de nucleósidos. Conclusiones: el uso de inhibidores de integrasa es un factor relevante en el control del riesgo cardiovascular en pacientes con virus de inmunodeficiencia humana.

Abstract Introduction: some antiretrovirals affect the lipid profile in human immunodeficiency virus patients increasing their cardiovascular risk. Integrase inhibitors generate little lipid alteration. The present study evaluated the best available evidence about changes in the lipid profile in human immunodeficiency virus patients who had switch from different antiretroviral therapies to schemes with integrase inhibitors. Methods: a systematic review with meta-analytic intention was carried out. From the question "How does antiretroviral schemes with integrase inhibitors impact in lipid profile in human immunodeficiency virus patients compared to antiretroviral schemes without integrase inhibitors?" an evidence search was done. Articles from experimental and observational studies were included and the quality was evaluated. An analysis by integrase inhibitor and lipid parameters was performed. Results: 17 relevant studies were identified and 2 878 patients were included in the quantitative synthesis. According to evidence, integrase inhibitors had a better lipid profile compared to other antiretrovirals. Dolutegravir had a better metabolic profile when it was compared with protease inhibitors. Raltegravir had a better lipid profile when it was compared to non-nucleoside analog reverse transcriptase inhibitors. Conclusions: integrase inhibitors are a relevant factor for cardiovascular risk control in patients with human immunodeficiency virus.

Short Communication: Integrase Strand Transfer Inhibitors Drug Resistance Mutations in Puerto Rico HIV-Positive Individuals.

The HIV-1 integrase viral protein is responsible for incorporating the viral DNA into the genomic DNA. The inhibition of viral integration into host cell DNA is part of recent therapeutic procedures. Combination therapy with protease and reverse transcriptase inhibitors has demonstrated good synergistic results in reducing viral replication. The purpose of this study is to assess the occurrence of integrase drug resistance mutations from the period comprising 2013 through 2018 in Puerto Rico (PR). We analyzed 131 nucleotide sequences available in our HIV genotyping database, and we performed drug resistance mutation analyses using the Stanford HIV Drug Resistance Database. Twenty-one sequences (16.03%) harbored major or resistance-associated mutations. We identified the Q148HKR, G140S, Y143R, N155H, S147G, and E138EA major drug resistance mutations and the D232DN, T97TA, E157Q, G163GART accessory mutations. We detected high-level drug resistance to Elvitegravir and Raltegravir (76.19% and 85.71%). Moreover, we identified sequences harboring drug resistance mutations that could provide resistance to Dolutegravir. The transmission of strains with integrase antiretroviral resistance has been previously documented in treatment naïve patients. Given the increase of patients treated with integrase inhibitors, surveillance of drug resistance mutations is an essential aspect of PR's clinical management of HIV infection.

HIV-1 resistance patterns to integrase inhibitors in Chilean patients with virological failure on raltegravir-containing regimens.

In this viewpoint we would like to describe our results in terms of resistance pattern in Chilean patients with virological failure (VF) on raltegravir (RAL)-containing-regimens and highlight the need for the concomitant availability of genotypic resistance testing to integrase strand transfer inhibitors (INSTIs) introduction in antiretroviral regimens, particularly in countries in South America. Indeed we found in our study the presence of two or more primary mutations in some of the participants which is associated with cross-resistance to all INSTIs. By using timely genotyping, we could optimally manage these patients, early after detection of VF.

Efficacy of Three Antiretroviral Regimens Initiated during Pregnancy: Clinical Experience in Rio de Janeiro.

Few studies have compared the clinical efficacy and adverse events of combined antiretroviral therapy (cART) regimens in pregnant women seeking obstetrical care. The objective of this study was to compare the efficacy (virus load response), adverse events, and obstetrical and neonatal outcomes of three different regimens of cART in HIV-infected pregnant women initiating treatment in Rio de Janeiro, Brazil. This was a retrospective cohort study of cART-naive pregnant women who initiated either ritonavir-boosted protease inhibitors (atazanavir or lopinavir), efavirenz, or raltegravir plus a backbone regimen. From 2014 to 2018, 390 pregnant women were followed over time. At baseline, the median viral load (VL) for HIV was 4.1 log copies/ml. Among participants who received cART for 2 to 7 weeks, the VL decline was greater for raltegravir (2.24 log copies/ml) than for efavirenz or protease inhibitors (P < 0.001). Virologic suppression was achieved in 87% of women on raltegravir near delivery versus 73% on efavirenz and 70% on protease inhibitors (P = 0.011). Patients on raltegravir achieved virologic suppression faster than those on other regimens (P = 0.019). Overall, the HIV perinatal infection rate was 1.5%. This clinical study compared three potent and well-tolerated cART regimens and demonstrated that a higher proportion of participants on raltegravir achieved an undetectable HIV VL near delivery (P = 0.011) compared to the other arms. These findings suggest that raltegravir-containing regimens are optimal regimens for women with HIV initiating treatment late in pregnancy.

Evidence for Disruption of Mg2+ Pair as a Resistance Mechanism Against HIV-1 Integrase Strand Transfer Inhibitors.

HIV-1 integrase is the enzyme responsible for integrating the viral DNA into the host genome and is one of the main targets for antiretroviral therapy; however, there are documented cases of resistance against all the currently used integrase strand transfer inhibitors (INSTIs). While some resistance-related mutations occur near the inhibitor's binding site, the mutation N155H occurs on the opposite side of the drug-interacting Mg2+ ions, thus, not interacting directly with the drug molecules and currently lacking an explanation for its resistance mechanism. Moreover, mutation N155H and the resistance-related mutation Q148H are mutually exclusive for unknown reasons. In the present study, we use molecular dynamics simulations to understand the impact of the N155H mutation in the HIV-1 integrase structure and dynamics, when alone or in combination with Q148H. Our findings suggest that the Mg2+ ions of the active site adopt different orientations in each of the mutants, causing the catalytic triad residues involved in the ion coordination to adapt their side-chain configurations, completely changing the INSTIs binding site. The change in the ion coordination also seems to affect the flexibility of the terminal viral DNA nucleotide near the active site, potentially impairing the induced-fit mechanism of the drugs. The explanations obtained from our simulations corroborate previous hypotheses drawn from crystallographic studies. The proposed resistance mechanism can also explain the resistance caused by other mutations that take place in the same region of the integrase and help uncover the structural details of other HIV-1 resistance mechanisms.

Raltegravir use and outcomes among children and adolescents living with HIV in the IeDEA global consortium.

INTRODUCTION: As integrase inhibitors become available in low- and middle-income countries (LMICs), they offer the potential to expand extremely limited treatment options available to children and adolescents. In LMICs, only small numbers have used raltegravir, primarily as part of third-line regimens. Using data from the IeDEA global consortium, we aimed to describe the characteristics of children on raltegravir-containing regimens and their outcomes. METHODS: We included data from 1994 to 2017 from children (age <18 years), from East and Southern Africa, Asia and South America, who received cART regimens containing raltegravir for ≥90 days. We describe their characteristics at raltegravir start, and their immunological and virological outcomes. RESULTS AND DISCUSSION: In total, 62 children were included, with median age at raltegravir initiation of 14.3 years (IQR 11.2 to 15.8) and median CD4 count of 276 cells/µL (IQR 68 to 494). Among 40 (65%) with drug resistance testing prior to raltegravir, 71% were resistant to at least one protease inhibitor (PI), and 32% had high-level resistance to at least one drug class. Most (n = 50; 81%) received raltegravir as part of third-line cART following PI-based regimens, and were on regimens containing four or more drugs (n = 47, 76%). By database closure, median duration on raltegravir was 2.0 years (IQR 0.8 to 3.0), 1 (1.6%) patient had died, 6 (9.7%) were lost to follow-up and 21 (34%) had discontinued raltegravir. Among 15 patients reporting reasons for stopping raltegravir, six discontinued because it was no longer available. Within one year of starting raltegravir, among 53 patients with VL measures, 40 (75%) had VL < 1000 copies/mL, and among 54 with a reported CD4 count, 45 (83%) and 36 (67%) were ≥350 and ≥500 cells/µL, respectively, with median CD4 count increasing to 517.5 cells/µL (IQR 288 to 810). CONCLUSIONS: Among children in LMICs, the initial use of raltegravir has been primarily for post PI-based cART. We found good virological and immunological outcomes despite frequent prior triple-class failure and high levels of drug resistance. Both access to raltegravir and long-term adherence to regimens with large pill-burdens remain challenging. Policies which promote earlier access to new drugs and simplify daily regimens for children and adolescents in LMICs are needed.