HIV-1 transmitted drug resistance in newly diagnosed individuals in Italy over the period 2015-21.

BACKGROUND: Transmitted drug resistance (TDR) is still a critical aspect for the management of individuals living with HIV-1. Thus, its evaluation is crucial to optimize HIV care. METHODS: Overall, 2386 HIV-1 protease/reverse transcriptase and 1831 integrase sequences from drug-naïve individuals diagnosed in north and central Italy between 2015 and 2021 were analysed. TDR was evaluated over time. Phylogeny was generated by maximum likelihood. Factors associated with TDR were evaluated by logistic regression. RESULTS: Individuals were mainly male (79.1%) and Italian (56.2%), with a median (IQR) age of 38 (30-48). Non-B infected individuals accounted for 44.6% (N = 1065) of the overall population and increased over time (2015-2021, from 42.1% to 51.0%, P = 0.002). TDR prevalence to any class was 8.0% (B subtype 9.5% versus non-B subtypes 6.1%, P = 0.002) and remained almost constant over time. Overall, 300 transmission clusters (TCs) involving 1155 (48.4%) individuals were identified, with a similar proportion in B and non-infected individuals (49.7% versus 46.8%, P = 0.148). A similar prevalence of TDR among individuals in TCs and those out of TCs was found (8.2% versus 7.8%, P = 0.707).By multivariable analysis, subtypes A, F, and CFR02_AG were negatively associated with TDR. No other factors, including being part of TCs, were significantly associated with TDR. CONCLUSIONS: Between 2015 and 2021, TDR prevalence in Italy was 8% and remained almost stable over time. Resistant strains were found circulating regardless of being in TCs, but less likely in non-B subtypes. These results highlight the importance of a continuous surveillance of newly diagnosed individuals for evidence of TDR to inform clinical practice.

Characterization of HIV-1 Reservoirs in Children and Adolescents: A Systematic Review and Meta-Analysis Toward Pediatric HIV Cure.

OBJECTIVE: To conduct a comprehensive, systematic review of the profile of HIV-1 reservoirs in children and adolescents with perinatally acquired HIV infection. STUDY DESIGN: Randomized and nonrandomized trials, cohort studies, and cross-sectional studies on HIV reservoirs in pediatric populations, published between 2002 and 2022, were included. Archived-drug resistance mutations (ADRMs) and the size of reservoirs were evaluated. Subgroup analyses were performed to characterize further the data, and the meta-analysis was done through random effect models. RESULTS: Overall, 49 studies from 17 countries worldwide were included, encompassing 2356 perinatally infected participants (48.83% females). There are limited data on the quantitative characterization of viral reservoirs in sub-Saharan Africa, with sensitive methodologies such as droplet digital polymerase chain reaction rarely employed. The overall prevalence of ADRMs was 37.80% (95% CI 13.89-65.17), with 48.79% (95% CI 0-100) in Africa, 42.08% (95% CI 6.68-82.71) in America, 23.88% (95% CI 14.34-34.90) in Asia, and 20.00% (95% CI 10.72-31.17) in Europe, without any difference between infants and adolescents (P = .656). Starting antiretroviral therapy (ART) before 2 months of age limited the levels of HIV-1 DNA (P = .054). Participants with long-suppressed viremia (>5 years) had lower levels of HIV-1 DNA (P = .027). Pre- and post-ART CD4 ≤29% and pre-ART viremia ≥5Log were all found associated with greater levels of HIV-1 DNA (P = .038, P = .047, and P = .041, respectively). CONCLUSIONS: The pooled prevalence of ADRMs is high in perinatally infected pediatric population, with larger proviral reservoir size driven by delayed ART initiation, a shorter period of viral suppression, and immunovirological failures. Thus, strategies for pediatric HIV functional cure should target children and adolescents with very early ART initiation, immunocompetence, and long-term viral suppression.

Managing low-level HIV viraemia in antiretroviral therapy: a systematic review and meta-analysis.

OBJECTIVE: HIV-1 management has advanced significantly with antiretroviral therapy (ART), yet challenges persist, including low-level HIV-1 viraemia (LLV). LLV presents a complex scenario, with varied definitions in the literature, reflecting uncertainties in its clinical interpretation. Questions arise regarding the underlying mechanisms of LLV, whether it signifies ongoing viral replication or stems from other factors. This study aimed to systematically review strategies for LLV management, providing insights into optimal clinical approaches. METHODS: MEDLINE, EMBASE, Cochrane Library, Web of Science and Canadian Agency for Drugs and Technologies in Health were searched for relevant literature on LLV management. We included studies published between 2004 and 2024, assessing interventions such as ART modification, genotypic resistance testing, adherence assessment, performing therapeutic drug monitoring, testing for chronic coinfections and assessing the viral reservoir via HIV DNA quantification. Meta-analyses were conducted where feasible. RESULTS: The systematic review identified 48 eligible records. Findings indicated limited evidence supporting the effectiveness of ART regimen modification in achieving virological suppression among individuals with LLV. However, studies assessing genotypic resistance testing revealed a significant association between resistance-associated mutations and virological suppression during LLV. Adherence to ART emerged as a critical determinant of treatment efficacy, with interventions showing promise in achieving viral suppression. The clinical utility of therapeutic drug monitoring in managing LLV remained inconclusive. Gaps in the literature were identified regarding follow-up scheduling, managing concurrent chronic infections and assessing inflammatory markers in LLV management. CONCLUSIONS: While ART modification may not consistently achieve virological suppression, genotypic resistance testing may offer insights into treatment outcomes. Adherence to ART emerged as a crucial factor, necessitating tailored interventions. However, further research is needed to elucidate the clinical utility of therapeutic drug monitoring and other management strategies. The study highlights the importance of ongoing research to refine therapeutic approaches and improve patient outcomes in LLV management. PROSPERO REGISTRATION NUMBER: CRD42024511492.

Management of low-level HIV viremia during antiretroviral therapy: Delphi consensus statement and appraisal of the evidence.

OBJECTIVE: While antiretroviral therapy (ART) is highly effective, detection of low levels of HIV-1 RNA in plasma is common in treated individuals. Given the uncertainties on the topic, we convened a panel of experts to consider different clinical scenarios, producing a Delphi consensus to help guide clinical practice. METHODS: A panel of 17 experts in infectious diseases, virology and immunology rated 32 statements related to four distinct scenarios: (1) low-level viremia during stable (≥6 months) first-line ART (≥2 consecutive HIV-1 RNA measurements 50-500 copies/mL); (2) a viral blip during otherwise suppressive ART (a HIV-1 RNA measurement 50-1000 copies/mL with adjacent measurements <50 copies/mL); (3) low-level viral rebound during previously suppressive ART (≥2 consecutive HIV-1 RNA measurements 50-500 copies/mL); (4) residual viremia during suppressive ART (persistent HIV-1 RNA quantification below 50 copies/mL). A systematic review, conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement, informed the 32 statements. The Delphi procedure was modified to include two voting rounds separated by a moderated group discussion. Grading of Recommendations, Assessment, Development, and Evaluations-based recommendations were developed. RESULTS: Overall, 18/32 statements (56.2%) achieved a strong consensus, 3/32 (9.4%) achieved a moderate consensus and 11/32 (34.4%) did not achieve a consensus. Across the four scenarios, the panel unanimously emphasised the importance of implementing specific interventions prior to considering therapy changes, including assessing adherence, testing for genotypic drug resistance and scheduling more frequent follow-up visits. Strategies indicated in selected circumstances included therapeutic drug monitoring, quantifying total HIV-1 DNA and evaluating concomitant chronic infections. CONCLUSIONS: While acknowledging the many uncertainties about source, significance and optimal management of low-level viremia during ART, the findings provide insights to help harmonise clinical practice. There is a need for well-designed randomised studies assessing different interventions to manage low-level viremia and future research regarding its definition.

PRESTIGIO RING: "An 80-year-old man living with HIV resistant to all four antiretroviral classes and desiring treatment simplification".

People aging with 4 antiretroviral class resistant HIV are a very challenging population. It is difficult to build up a fully suppressive regimen, and the high prevalence of comorbidities and polypharmacy may cause drug-drug interactions and put adherence at risk. We herein present the case of an 80-year-old man, participating in the PRESTIGIO registry, asking for a reduction in his antiretroviral burden while on polypharmacy for his comorbidities.

PRESTIGIO RING "a 59-year-old man with multidrug resistant HIV-1 infection failing a regimen including dolutegravir, rilpivirine, atazanavir/cobicistat: successful treatment tailoring based on genotypic and phenotypic resistance tests".

Management of virological failure in heavily treatment-experienced people with multidrug-resistant (MDR) HIV infection is a serious clinical challenge. New drugs with novel mechanisms of action have recently been approved, and their use has improved the outcome of subjects with limited treatment options (LTO). In this setting, the choice of antiretroviral therapy (ART) should be tailored based on the pattern of resistance, treatment history and patients' individual characteristics. While genotypic resistance testing is the reference method for analysing residual drug susceptibility, phenotypic resistance testing can provide additional support when facing LTO. Herein, we present the case of a patient with MDR HIV-1 infection on virological failure enrolled in the PRESTIGIO Registry. The salvage ART regimen, which included drugs with novel mechanisms of action (MoA), was tailored to the patient's clinical characteristics and on the resistance pattern explored with genotypic and phenotypic investigation, allowing the achievement of viro-immunological success. The use of recently approved drugs with novel MoA, combined with an optimized background regimen, may also achieve virological suppression in people with LTO.

Transmitted Drug Resistance to Integrase-Based First-Line Human Immunodeficiency Virus Antiretroviral Regimens in Mediterranean Europe.

BACKGROUND: We evaluated the prevalence of transmitted drug resistance (TDR) to integrase strand-transfer inhibitors (INSTIs) and nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) and of clinically relevant resistance (CRR) in newly diagnosed people with human immunodeficiency virus (HIV; PWH) naive to antiretroviral therapy (ART) in Europe. METHODS: MeditRes is a consortium that includes ART-naive PWH newly diagnosed in France, Greece, Italy, Portugal, and Spain during 2018-2021. Reverse transcriptase and INSTI sequences were provided by participating centers. To evaluate the prevalence of surveillance drug resistance mutations (SDRM), we used the calibrated population resistance tools from the Stanford HIV website. To evaluate CRR, defined as any resistance level ≥3, we used the Stanford HIV Drug Resistance Database v.9.1 algorithm. RESULTS: We included 2705 PWH, 72% men, median age of 37 years (interquartile range, 30-48); 43.7% were infected by non-B subtypes. The prevalence of INSTI-SDRMs was 0.30% (T66I, T66A, E92Q, E138T, E138K, Y143R, S147G, R263K; all n=1) and the prevalence of NRTI-SDRMs was 5.77% (M184V: 0.85%; M184I: 0.18%; K65R/N: 0.11%; K70E: 0.07%; L74V/I: 0.18%; any thymidine analog mutations: 4.36%). INSTI-CRR was 2.33% (0.15% dolutegravir/bictegravir, 2.29% raltegravir/elvitegravir) and 1.74% to first-line NRTIs (0.89% tenofovir/tenofovir alafenamide, 1.74% abacavir, 1.07% lamivudine/emtricitabine). CONCLUSIONS: We present the most recent data on TDR to integrase-based first-line regimens in Europe. Given the low prevalence of CRR to second-generation integrase inhibitors and to first-line NRTIs during 2018-2021, it is unlikely that newly diagnosed PWH in MeditRes countries would present with baseline resistance to a first-line regimen based on second-generation integrase inhibitors.

The effects of orally administered lactoferrin in the prevention and management of viral infections: A systematic review.

It has been demonstrated that lactoferrin (LF) plays a role in host defence, but evidence on its potential antiviral property from clinical studies is fragmented. Our systematic review aimed at identifying the effects of orally administered LF against virus infections. The systematic search was conducted on PubMed, Scopus, Web of Science, BioRxiv.org and ClinicalTrials.gov from database inception to 7th January 2021. Eligible articles investigated any virus family and provided data on the effects of orally administered LF of any origin in the prevention and/or management of confirmed viral infections in people of any age. A narrative synthesis of the results was performed. Quality was assessed with the Cochrane Risk-Of-Bias and ROBINS-1 tools. A total of 27 records were included, nine of which were registered protocols. We found data on Flaviviridae (n = 10), Retroviridae (n = 3), Coronaviridae (n = 2), Reoviridae (n = 2) and Caliciviridae (n = 1). Most published trials were at high risk of bias. The findings were heterogeneous across and within viral families regarding virological, immunological and biological response, with no clear conclusion. Some weak but positive results were reported about decrease of symptom severity and duration, or reduction in viral loads. Despite high tolerability, the effects of LF as oral supplement are still inconsistent, both in preventing and managing viral infections. Small sample sizes, variety in recruitment and treatment protocols, and low study quality may have contributed to such heterogeneity. Better-designed studies are needed to further investigate its potential benefits against viral infections, including SARS-CoV-2.

EuCARE-POSTCOVID Study: a multicentre cohort study on long-term post-COVID-19 manifestations.

BACKGROUND: Post-COVID-19 condition refers to persistent or new onset symptoms occurring three months after acute COVID-19, which are unrelated to alternative diagnoses. Symptoms include fatigue, breathlessness, palpitations, pain, concentration difficulties ("brain fog"), sleep disorders, and anxiety/depression. The prevalence of post-COVID-19 condition ranges widely across studies, affecting 10-20% of patients and reaching 50-60% in certain cohorts, while the associated risk factors remain poorly understood. METHODS: This multicentre cohort study, both retrospective and prospective, aims to assess the incidence and risk factors of post-COVID-19 condition in a cohort of recovered patients. Secondary objectives include evaluating the association between circulating SARS-CoV-2 variants and the risk of post-COVID-19 condition, as well as assessing long-term residual organ damage (lung, heart, central nervous system, peripheral nervous system) in relation to patient characteristics and virology (variant and viral load during the acute phase). Participants will include hospitalised and outpatient COVID-19 patients diagnosed between 01/03/2020 and 01/02/2025 from 8 participating centres. A control group will consist of hospitalised patients with respiratory infections other than COVID-19 during the same period. Patients will be followed up at the post-COVID-19 clinic of each centre at 2-3, 6-9, and 12-15 months after clinical recovery. Routine blood exams will be conducted, and patients will complete questionnaires to assess persisting symptoms, fatigue, dyspnoea, quality of life, disability, anxiety and depression, and post-traumatic stress disorders. DISCUSSION: This study aims to understand post-COVID-19 syndrome's incidence and predictors by comparing pandemic waves, utilising retrospective and prospective data. Gender association, especially the potential higher prevalence in females, will be investigated. Symptom tracking via questionnaires and scales will monitor duration and evolution. Questionnaires will also collect data on vaccination, reinfections, and new health issues. Biological samples will enable future studies on post-COVID-19 sequelae mechanisms, including inflammation, immune dysregulation, and viral reservoirs. TRIAL REGISTRATION: This study has been registered with ClinicalTrials.gov under the identifier NCT05531773.

PRESTIGIO RING: "A 59-year-old HIV-1 positive, highly treatment-experienced woman failing darunavir/ ritonavir plus raltegravir".

Management of heavily treatment experienced (HTE) people with HIV remains a challenge. Tailored antiretroviral therapy (ART) is needed in this fragile population who almost invariably harbor viral quasispecies with resistance-associated mutations (RAMs). The reference method for HIV genotypic resistance testing (GRT) has long been Sanger sequencing (SS), but next-generation sequencing (NGS), following recent progress in workflow and cost-effectiveness, is replacing SS because of higher sensitivity. From the PRESTIGIO Registry, we present a case of a 59-year-old HTE woman who failed darunavir/ritonavir plus raltegravir at low-viremia levels due mainly to high pill burden and poor adherence. NGS-GRT was performed on HIV-RNA at failure and the results were compared to all past SS-GRT data available (historical genotype). In this case, NGS-GRT did not detect any minority drug-resistant variants. After discussing several therapeutic options, the treatment was changed to dolutegravir 50 mg twice daily plus doravirine 100 mg once a day, based on clinical history, adherence issues, and pill burden, as well as the historical SS-GRT and the latest NGS-GRT results. At six months follow-up visit, the patient had HIV-RNA below 30 copies/ml and CD4+ T cell count increased from 673 cells/ mm3 to 688 cells/ mm3. Close follow-up of this patient is ongoing.

Evaluation of HIV-1 capsid genetic variability and lenacapavir (GS-6207) drug resistance-associated mutations according to viral clades among drug-naive individuals.

OBJECTIVES: We evaluated the HIV-1 capsid genetic variability and lenacapavir drug resistance-associated mutations (DRMs) among drug-naive individuals across HIV-1 clades. METHODS: A total of 2031 HIV-1 sequences from drug-naive patients were analysed for capsid amino acid modification and the prevalence of lenacapavir DRMs. Amino acid positions with <5% variability were considered as conserved and variability was analysed by HIV-1 clades. RESULTS: Overall, 63% (148/232) of amino acid positions were conserved in the capsid protein. Of note, conservation was consistent in specific binding residues of cellular factors involved in viral replication [CypA (G89, P90), CPSF6 (Q4, N57, N74, A77, K182) and TRIM-NUP153 (R143)], while N183 (12.31%) was the only non-conserved lenacapavir binding residue. The overall prevalence (95% CI) of lenacapavir DRMs was 0.14% (0.05-0.44) (3/2031), with M66I (0.05%) and Q67H (0.05%) observed in subtype C, and T107N (0.05%) observed in CRF01_AE. Moreover, polymorphic mutations M66C (n = 85; 4.18%), Q67K (n = 78; 3.84%), K70R (n = 7; 0.34%), N74R (n = 57; 2.81%) and T107L (n = 82; 4.03%) were observed at lenacapavir resistance-associated positions. CONCLUSIONS: The low level of lenacapavir DRMs (<1%) supports its predicted effectiveness for treatment and prevention, regardless of HIV-1 clades. The established conserved regions hence serve as a hallmark for the surveillance of novel mutations potentially relevant for lenacapavir resistance.

Archiving of mutations in HIV-1 cellular reservoirs among vertically infected adolescents is contingent with clinical stages and plasma viral load: Evidence from the EDCTP-READY study.

INTRODUCTION: Globally, HIV-related adolescent deaths have increased about 50%, especially for those who are vertically infected. This could be driven by archived drug resistance mutations (DRMs) as children grow up, which might jeopardize antiretroviral therapy (ART). Our objective was to compare HIV-1 genotypic variation between plasma RNA and proviral DNA of vertically infected adolescents (aged 10-19 years) failing ART. METHODS: A comparative study was conducted in 2019 among 296 adolescents with perinatal HIV infection (ALPHI) failing ART in health facilities of the Centre Region of Cameroon. The WHO clinical stage, CD4 count and plasma viral load (PVL) were measured. For those failing ART (PVL ≥ 1000 copies/mL), RNA (plasma) and proviral DNA (buffy coat) were sequenced in the pol gene at Chantal BIYA International Reference Centre (CIRCB), Yaoundé, Cameroon. HIV-1 subtypes and DRMs were interpreted using Stanford HIVdb v.8.8 and MEGA-X. RESULTS: Of the 30% (89/296) failing ART, 81 had both RNA and DNA sequences generated and three were excluded for APOBEC mutations: the mean age was 16 ± 3 years; female-to-male ratio was 3:5; median PVL was 46 856 copies/mL [interquartile range (IQR): 19 898-271 410]; median CD4 count was 264 cells/µL (IQR: 131-574); and 42% were at WHO clinical stage 3/4. Subtype concordance between RNA and DNA viral strains was 100%, with CRF02_AG being predominant (65%) and two potential new recombinants found (A1/G/K; F1/G). Adolescents with DRMs were significantly higher in plasma than in proviral DNA (92% vs. 86%, p < 0.0001). Prevalent DRMs by drug class (RNA vs. DNA respectively) were at position M184 (74% vs. 67%) for nucleoside reverse transcriptase inhibitors (NRTIs), K103 (63% vs. 59%) for non-NRTIs, and V82, L76 and M46 (2% vs. 2%) for protease inhibitors. A total of 35% (27/78) of adolescents had concordant DRM profiles in RNA and DNA, while 27% (21/78) had DRMs only in proviral DNA. The presence of archived DRMs was associated with advanced clinical stage 3/4 (OR = 0.14, p = 0.0003) and PVL < 5 Log (Copies/mL) (OR: 4.88, p = 0.006). CONCLUSIONS: Although plasma RNA remains more sensitive for detecting HIV-1 DRMs, about a quarter of ALPHI experiencing ART failure in an African setting might have archived DRMs in viral reservoirs, indicating clinically occult resistance. Thus, to ensure effective ART success, proviral DNA profiling (alongside RNA genotyping) would provide additional DRMs for adolescents with advanced clinical stages and/or moderate PVL.

Targeting SARS-CoV-2 nsp13 Helicase and Assessment of Druggability Pockets: Identification of Two Potent Inhibitors by a Multi-Site In Silico Drug Repurposing Approach.

The SARS-CoV-2 non-structural protein 13 (nsp13) helicase is an essential enzyme for viral replication and has been identified as an attractive target for the development of new antiviral drugs. In detail, the helicase catalyzes the unwinding of double-stranded DNA or RNA in a 5' to 3' direction and acts in concert with the replication-transcription complex (nsp7/nsp8/nsp12). In this work, bioinformatics and computational tools allowed us to perform a detailed conservation analysis of the SARS-CoV-2 helicase genome and to further predict the druggable enzyme's binding pockets. Thus, a structure-based virtual screening was used to identify valuable compounds that are capable of recognizing multiple nsp13 pockets. Starting from a database of around 4000 drugs already approved by the Food and Drug Administration (FDA), we chose 14 shared compounds capable of recognizing three out of four sites. Finally, by means of visual inspection analysis and based on their commercial availability, five promising compounds were submitted to in vitro assays. Among them, PF-03715455 was able to block both the unwinding and NTPase activities of nsp13 in a micromolar range.

Genotypic HIV-1 tropism determination might help to identify people with exhausted treatment options and advanced disease.

OBJECTIVES: To evaluate HIV-1 tropism in 1382 combined antiretroviral therapy (cART)-experienced patients failing therapy to characterize those with exhausted therapeutic options. METHODS: HIV-1 genotypic tropism was inferred through Geno2Pheno by estimating the false-positive-rate (FPR) values. Cumulative resistance and drug activity were evaluated by Stanford algorithm. RESULTS: Overall, median (IQR) CD4 count (cells/mm3) nadir and at last genotypic resistance test (GRT) available were 98 (33-211) and 312 (155-517), respectively. Considering HIV-1 tropism, 30.5% had X4/dual-mixed strains (FPR ≤5%: 22.2%; FPR 5%-10%: 8.3%). By stratifying according to tropism, by decreasing FPR, a significant decrease of CD4 nadir and at last GRT was observed. The proportion of individuals with CD4 count <200 cells/mm3, who were perinatally infected and with a long treatment history significantly increased as FPR levels decreased. Regarding resistance, 933 (67.5%) individuals accumulated at least one class resistance, with 52.7%, 48.2%, 23.5% and 13.2% of individuals showing resistance to NRTIs, NNRTIs, PIs and INIs; while 23.2%, 27.2%, 14.3% and 2.8% harboured resistance to 1, 2, 3 and 4 classes, respectively. Individuals with FPR ≤5% showed a significantly higher level of resistance to PIs, NRTIs and INIs compared with others. The proportion of individuals harbouring strains susceptible to ≤2 active drugs was only about 2%; nonetheless, this proportion doubled (4.6%) in patients infected with FPR ≤5%. CONCLUSIONS: Our findings showed that a small proportion of cART failing individuals have limited therapeutic options. However, tropism determination might help to identify people who have accumulated a high level of resistance and have a greater risk of advanced disease.

Baseline integrase drug resistance mutations and conserved regions across HIV-1 clades in Cameroon: implications for transition to dolutegravir in resource-limited settings.

BACKGROUND: Transition to dolutegravir-based regimens in resource-limited settings (RLS) requires prior understanding of HIV-1 integrase variants and conserved regions. Therefore, we evaluated integrase drug resistance mutations (DRMs) and conserved regions amongst integrase strand transfer inhibitor (INSTI)-naive patients harbouring diverse HIV-1 clades in Cameroon. METHODS: A cross-sectional study was conducted amongst 918 INSTI-naive patients from Cameroon (89 ART-naive and 829 ART-experienced patients). HIV-1 sequences were interpreted regarding INSTI-DRMs using the Stanford HIVdb v8.9-1 and the 2019 IAS-USA list. Amino acid positions with <1% variability were considered as highly conserved. Subtyping was performed by phylogeny. RESULTS: Overall prevalence (95% CI) of INSTI-DRMs was 0.8% (0.4-1.7), with 0.0% (0.0-4.0) amongst ART-naive versus 0.9% (0.5-1.9) amongst ART-experienced patients; P = 0.44. Accessory mutations (95% CI) were found in 33.8% (30.9-37.0), with 38.2% (28.1-49.1) amongst ART-naive versus 33.4% (30.4-36.7) amongst ART-experienced patients; P = 0.21. Of 288 HIV-1 integrase amino acid positions, 58.3% were highly conserved across subtypes in the following major regions: V75-G82, E85-P90, H114-G118, K127-W132, E138-G149, Q168-L172, T174-V180, W235-A239 and L241-D253. Wide genetic diversity was found (37 clades), including groups M (92.3%), N (1.4%), O (6.2%) and P (0.1%). Amongst group M, CRF02_AG was predominant (47.4%), with a significantly higher frequency (95% CI) of accessory mutations compared with non-AG [41.4% (36.8-46.0) versus 27.1% (23.3-31.2) respectively; P < 0.001]. CONCLUSIONS: The low baseline of INSTI-DRMs (<1%) in Cameroon suggests effectiveness of dolutegravir-based regimens. In spite of high conservation across clades, the variability of accessory mutations between major circulating strains underscores the need for monitoring the selection of INSTI-DRMs while scaling up dolutegravir-based regimens in RLS.

Virological response and resistance profile in highly treatment-experienced HIV-1-infected patients switching to dolutegravir plus boosted darunavir in clinical practice.

OBJECTIVES: We evaluated the virological response and resistance profile in combined antiretroviral therapy (cART)-experienced HIV-1-infected patients starting a dual therapy with dolutegravir (DTG) and boosted darunavir (bDRV) for the first time. METHODS: Survival analyses were used to evaluate virological success (VS) and virological rebound (VR) in viraemic and virologically suppressed patients, respectively. Major resistance mutations (MRMs) and genotypic susceptibility score (GSS) were evaluated at baseline and after switch. RESULTS: Overall, 130 patients [62 (47.7%) viraemic; 68 (52.3%) virologically suppressed] were retrospectively analysed. At the moment of switch, 81.5% accumulated one or more MRM [protease inhibitor (PI), 35.7%; nucleoside(t)ide reverse transcriptase inhibitor (NRTI), 77.5%; non-NRTI, 69.0%; integrase inhibitor (INI), 10.1%), but 77.7% harboured strains fully susceptible to DTG + bDRV. In viraemic patients, the overall probability of VS by 12 months of treatment was 91.7%. In virologically suppressed patients, the overall probability of VR was 10.5% by 24 months after therapy start. Patients with previous time under virological suppression ≤ 6 months showed a higher VR probability compared with others (37.5% vs. 6.7%, P < 0.002). Among 13 non-responding patients for whom a genotypic resistance test result at failure was available, only two (15.4%) accumulated further resistance in integrase (Y143C/H/R; S147G and N155H) and protease (V32I, L33F, I54L). CONCLUSIONS: In highly treatment-experienced patients, the use of dual therapy based on DTG + bDRV appears to be a very good regimen for switch therapy, with a high rate of virological control in both viraemic and virologically suppressed patients. Among non-responding patients, the selection of further resistance is a rare event.

Current status of antivirals and druggable targets of SARS CoV-2 and other human pathogenic coronaviruses.

Coronaviridae is a peculiar viral family, with a very large RNA genome and characteristic appearance, endowed with remarkable tendency to transfer from animals to humans. Since the beginning of the 21st century, three highly transmissible and pathogenic coronaviruses have crossed the species barrier and caused deadly pneumonia, inflicting severe outbreaks and causing human health emergencies of inconceivable magnitude. Indeed, in the past two decades, two human coronaviruses emerged causing serious respiratory illness: severe acute respiratory syndrome coronavirus (SARS-CoV-1) and Middle Eastern respiratory syndrome coronavirus (MERS-CoV), causing more than 10,000 cumulative cases, with mortality rates of 10 % for SARS-CoV-1 and 34.4 % for MERS-CoV. More recently, the severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) has emerged in China and has been identified as the etiological agent of the recent COVID-19 pandemic outbreak. It has rapidly spread throughout the world, causing nearly 22 million cases and ∼ 770,000 deaths worldwide, with an estimated mortality rate of ∼3.6 %, hence posing serious challenges for adequate and effective prevention and treatment. Currently, with the exception of the nucleotide analogue prodrug remdesivir, and despite several efforts, there is no known specific, proven, pharmacological treatment capable of efficiently and rapidly inducing viral containment and clearance of SARS-CoV-2 infection as well as no broad-spectrum drug for other human pathogenic coronaviruses. Another confounding factor is the paucity of molecular information regarding the tendency of coronaviruses to acquire drug resistance, a gap that should be filled in order to optimize the efficacy of antiviral drugs. In this light, the present review provides a systematic update on the current knowledge of the marked global efforts towards the development of antiviral strategies aimed at coping with the infection sustained by SARS-CoV-2 and other human pathogenic coronaviruses, displaying drug resistance profiles. The attention has been focused on antiviral drugs mainly targeting viral protease, RNA polymerase and spike glycoprotein, that have been tested in vitro and/or in clinical trials as well as on promising compounds proven to be active against coronaviruses by an in silico drug repurposing approach. In this respect, novel insights on compounds, identified by structure-based virtual screening on the DrugBank database endowed by multi-targeting profile, are also reported. We specifically identified 14 promising compounds characterized by a good in silico binding affinity towards, at least, two of the four studied targets (viral and host proteins). Among which, ceftolozane and NADH showed the best multi-targeting profile, thus potentially reducing the emergence of resistant virus strains. We also focused on potentially novel pharmacological targets for the development of compounds with anti-pan coronavirus activity. Through the analysis of a large set of viral genomic sequences, the current review provides a comprehensive and specific map of conserved regions across human coronavirus proteins which are essential for virus replication and thus with no or very limited tendency to mutate. Hence, these represent key druggable targets for novel compounds against this virus family. In this respect, the identification of highly effective and innovative pharmacological strategies is of paramount importance for the treatment and/or prophylaxis of the current pandemic but potentially also for future and unavoidable outbreaks of human pathogenic coronaviruses.

Identification of gp120 polymorphisms in HIV-1 B subtype potentially associated with resistance to fostemsavir.

OBJECTIVES: We evaluated natural resistance to the new antiretroviral fostemsavir and its potential association with other HIV-1 gp120 polymorphisms. METHODS: A total of 1997 HIV-1 B subtype gp120 sequences from the Los Alamos HIV Database were analysed for mutation prevalence at fostemsavir resistance-associated positions and potential association with other gp120 polymorphisms. The role of each fostemsavir resistance-related position and the correlated gp120 mutations, both in protein stability and in reducing the binding affinity between antibody and/or T cell lymphocyte epitopes and the MHC molecules, was estimated. RESULTS: The prevalence of fostemsavir resistance mutations was as follows: L116Q (0.05%), S375H/M/T (0.55%/1.35%/17.73%, the latter being far less relevant in determining resistance), M426L (7.56%), M434I (4.21%) and M475I (1.65%). Additionally, the M426R polymorphism had a prevalence of 16.32%. A significantly higher prevalence in X4 viruses versus R5 viruses was found only for S375M (0.69% versus 3.93%, P = 0.009) and S375T (16.60% versus 22.11%, P = 0.030). Some fostemsavirv resistance positions positively and significantly correlated with specific gp120 polymorphisms: S375T with I371V; S375M with L134W, I154V and I323T; M475I with K322A; and M426R with G167N, K192T and S195N. The topology of the dendrogram suggested the existence of three distinct clusters (bootstrap ≥0.98) involving these fostemsavir resistance mutations and gp120 polymorphisms. Interestingly, all clustered mutations are localized in class I/II-restricted T cell/antibody epitopes, suggesting a potential role in immune HIV escape. CONCLUSIONS: A low prevalence of known fostemsavir resistance mutations was found in the HIV-1 B subtype. The detection of novel HIV-1 gp120 polymorphisms potentially relevant for fostemsavir resistance deserves new in-depth in vitro investigations.

Prevalence of doravirine-associated resistance mutations in HIV-1-infected antiretroviral-experienced patients from two large databases in France and Italy.

OBJECTIVES: Doravirine, a novel NNRTI, selects for specific mutations in vitro, including mutations at reverse transcriptase (RT) positions 106, 108, 188, 227, 230 and 234. The aim of this study was to examine the prevalence of doravirine-associated resistance mutations in HIV-1-infected antiretroviral-experienced patients. METHODS: Doravirine-associated resistance mutations identified in vitro or in vivo were studied in a set of 9199 HIV-1 RT sequences from HIV-1 antiretroviral-experienced patients, including 381 NNRTI-failing patients in France and Italy between 2012 and 2017. The following mutations were considered as resistance mutations: V106A/M, V108I, Y188L, G190S, F227C/L/V, M230I/L, L234I, P236L, K103N + Y181C, K103N + P225H and K103N + L100I. RESULTS: The frequencies of doravirine-associated resistance mutations (total dataset versus NNRTI-failing patients) were: V106A/M, 0.8% versus 2.6%; V108I, 3.3% versus 9.2%; Y188L, 1.2% versus 2.6%; G190S, 0.3% versus 2.1%; F227C/L/V, 0.5% versus 1.8%; M230I/L, 2.8% versus 0%; L234I, 0.1% versus 0.5%; K103N + Y181C, 3.9% versus 3.9%; K103N + P225H, 2.9% versus 4.7%; and K103N + L100I, 1.7% versus 3.9%, with a significantly higher proportion of these mutations in the NNRTI-failing group (P < 0.05), except for M230I/L and K103N + Y181C. The overall prevalence of sequences with at least one doravirine-associated resistance mutation was 12.2% and 34.9% in the total dataset and NNRTI-failing patients (P < 0.001), respectively. In comparison, the prevalence of the common NNRTI mutations V90I, K101E/P, K103N/S, E138A/G/K/Q/R/S, Y181C/I/V and G190A/E/S/Q were higher (8.9%, 7.9%, 28.6%, 12.6%, 14.2% and 8.9%, respectively). CONCLUSIONS: These results suggest that doravirine resistance in antiretroviral-experienced patients generally and specifically among NNRTI-failing patients is lower than resistance to other NNRTIs currently used, confirming its distinguishing resistance pattern.

Programme quality indicators of HIV drug resistance among adolescents in urban versus rural settings of the centre region of Cameroon.

BACKGROUND: The high rate of mortality among HIV-vertically infected adolescents might be favoured by HIV drug resistance (HIVDR) emergence, which calls for timeous actions in this underserved population. We thus sought to evaluate program quality indicators (PQIs) of HIVDR among HIV-vertically infected adolescents on antiretroviral therapy (ART). METHODS: A study was conducted in the Centre region of Cameroon among adolescents (10-19 years) receiving ART in two urban (The Mother-Child Centre of the Chantal BIYA Foundation, the National Social Welfare Hospital) and three rural (Mfou District Hospital, Mbalmayo District Hospital and Nkomo Medical Center) health facilities. Following an exhaustive sampling from ART registers, patient medical files and pharmacy records, data was abstracted for seven PQIs: on-time drug pick-up; retention in care; pharmacy stock outs; dispensing practices; viral load coverage; viral suppression and adequate switch to second-line. Performance in PQIs was interpreted following the WHO-recommended thresholds (desirable, fair and/or poor); with p < 0.05 considered significant. RESULTS: Among 967 adolescents (888 urban versus 79 rural) registered in the study sites, validated data was available for 633 (554 in urban and 79 in rural). Performance in the urban vs. rural settings was respectively: on-time drug pick-up was significantly poorer in rural (79% vs. 46%, p = 0.00000006); retention in care was fair in urban (80% vs. 72%, p = 0.17); pharmacy stock outs was significantly higher in urban settings (92% vs. 50%, p = 0.004); dispensing practices was desirable (100% vs. 100%, p = 1.000); viral load coverage was desirable only in urban sites (84% vs. 37%, p < 0.0001); viral suppression was poor (33% vs. 53%, p = 0.08); adequate switch to second-line varied (38.1% vs. 100%, p = 0.384). CONCLUSION: Among adolescents on ART in Cameroon, dispensing practices are appropriate, while adherence to ART program and viral load coverage are better in urban settings. However, in both urban and rural settings, pharmacy stock outs, poor viral suppression and inadequate switch to second-line among adolescents require corrective public-health actions to limit HIVDR and to improve transition towards adult care in countries sharing similar programmatic features.