Drug resistance in the HIV-1-infected paediatric population worldwide: a systematic review

Resistance Mutation Patterns among HIV-1-Infected Children and Features of the Program for Prevention of Mother-to-Child Transmission in Vietnam's Central Highlands and Southern Regions, 2017-2021

The Vietnam Ministry of Health (MOH) has intensified efforts in its aim to eliminate AIDS by 2030. Expanding the program for prevention of mother-to-child transmission (PMTCT) is a significant step towards achieving this goal. However, there are still HIV-exposed children who do not have access to PMTCT services, and some who have participated in the program but still contracted HIV. This study focused on assessing the prevalence and profile of HIV mutations among children under 18 months of age who had recently tested positive for HIV, while gaining insights into the implementation of early infant diagnostic (EID) tests. Between 2017 and 2021, 3.43% of 5854 collected dry blood spot (DBS) specimens from Vietnam's Central and Southern regions showed positive EID results. This study identified a high prevalence of resistance mutations in children, totaling 62.9% (95% CI: 53.5-72.3). The highest prevalence of mutations was observed for NNRTIs, with 57.1% (95% CI: 47.5-66.8). Common mutations included Y181C and K103N (NNRTI resistance), M184I/V (NRTI resistance), and no major mutations for PI. The percentage of children with any resistance mutation was significantly higher among those who received PMTCT interventions (69.2%; 95% CI: 50.5-92.6%) compared with those without PMTCT (45.0%; 95% CI: 26.7-71.1%) with χ2 = 6.06, p = 0.0138, and OR = 2.75 (95% CI: 1.13-6.74). Mutation profiles revealed that polymorphic mutations could be present regardless of whether PMTCT interventions were implemented or not. However, non-polymorphic drug resistance mutations were predominantly observed in children who received PMTCT measures. Regarding PMTCT program characteristics, this study highlights the issue of late access to HIV testing for both mothers and their infected children. Statistical differences were observed between PMTCT and non-PMTCT children. The proportion of late detection of HIV infection and breastfeeding rates were significantly higher among non-PMTCT children (p < 0.05). Comparative analysis between children with low viral load (≤200 copies/mL) and high viral load (>200 copies/mL) showed significant differences between the mothers' current ART regimens (p = 0.029) and the ARV prophylaxis regimen for children (p = 0.016). These findings emphasize the need for comprehensive surveillance to assess the effectiveness of the PMTCT program, including potential transmission of HIV drug-resistance mutations from mothers to children in Vietnam.

Pretreatment and Acquired Drug Resistance in Children With Human Immunodeficiency Virus Type 1 in Jos, Nigeria

We determined pretreatment and acquired human immunodeficiency virus (HIV) drug resistance among children with HIV type 1 (HIV-1) in Jos, Nigeria. The majority (71%) of those who failed first-line antiretroviral therapy were on a nevirapine-containing regimen. The prevalence of pretreatment (48%) and acquired (76%) HIV drug resistance mutations was high in our study. Wider access to HIV drug resistance testing after treatment failure is necessary to optimize second-line treatment options among children with HIV in Nigeria.

Temporal trends and transmission dynamics of pre-treatment HIV-1 drug resistance within and between risk groups in Kenya, 1986-2020

BACKGROUND

Evidence on the distribution of pre-treatment HIV-1 drug resistance (HIVDR) among risk groups is limited in Africa. We assessed the prevalence, trends and transmission dynamics of pre-treatment HIVDR within and between MSM, people who inject drugs (PWID), female sex workers (FSWs), heterosexuals (HETs) and perinatally infected children in Kenya.

METHODS

HIV-1 partial pol sequences from antiretroviral-naive individuals collected from multiple sources between 1986 and 2020 were used. Pre-treatment reverse transcriptase inhibitor (RTI), PI and integrase inhibitor (INSTI) mutations were assessed using the Stanford HIVDR database. Phylogenetic methods were used to determine and date transmission clusters.

RESULTS

Of 3567 sequences analysed, 550 (15.4%, 95% CI: 14.2-16.6) had at least one pre-treatment HIVDR mutation, which was most prevalent amongst children (41.3%), followed by PWID (31.0%), MSM (19.9%), FSWs (15.1%) and HETs (13.9%). Overall, pre-treatment HIVDR increased consistently, from 6.9% (before 2005) to 24.2% (2016-20). Among HETs, pre-treatment HIVDR increased from 6.6% (before 2005) to 20.2% (2011-15), but dropped to 6.5% (2016-20). Additionally, 32 clusters with shared pre-treatment HIVDR mutations were identified. The majority of clusters had R0 ≥ 1.0, indicating ongoing transmissions. The largest was a K103N cluster involving 16 MSM sequences sampled between 2010 and 2017, with an estimated time to the most recent common ancestor (tMRCA) of 2005 [95% higher posterior density (HPD), 2000-08], indicating propagation over 12 years.

CONCLUSIONS

Compared to HETs, children and key populations had higher levels of pre-treatment HIVDR. Introduction of INSTIs after 2017 may have abrogated the increase in pre-treatment RTI mutations, albeit in the HET population only. Taken together, our findings underscore the need for targeted efforts towards equitable access to ART for children and key populations in Kenya.

Rescue therapy with an albuvirtide-based antiretroviral regimen in an HIV-infected child with multidrug resistance and multiple opportunistic infections: a case report

BACKGROUND

Managing multidrug-resistant (MDR) HIV infections in children is particularly challenging due to the lack of experience with new drugs in the pediatric setting. Second-line albuvirtide (ABT) with an optimized antiretroviral background therapy was approved for adults and adolescents after first-line treatment failure. This paper describes the treatment outcomes and adverse effects of an ABT-based dual-active antiretroviral treatment regimen in a child with MDR HIV strains.

CASE PRESENTATION

A 13 year-old Chinese female patient infected with MDR HIV strains showed a decrease in viral load (from 4.48 log10 to 1.73 log10) and an increase in CD4 + T cells (from 15 to 308 cells/µl) after 12 months of treatment with an ABT-based antiretroviral regimen. The child showed no relevant drug-related adverse reactions.

CONCLUSIONS

The case reported here could suggest that an ABT-based antiretroviral therapy might be beneficial and without relevant toxicity in children with MDR HIV. Infectiologists specializing in managing HIV should be prepared to manage an increasing number of children with MDR HIV. ABT might be a new treatment option for MDR HIV infection in children.

HIV-1 Disease Progression and Drug Resistance Mutations among Children on First-Line Antiretroviral Therapy in Ethiopia

Background: High rates of disease progression and HIV drug resistance (HIVDR) among adults taking highly active antiretroviral treatment (HAART) in Sub-Saharan Africa were previously documented. However, children were generally not considered despite their greater risk. Hence, this study was aimed to evaluate HIV-1 disease progression and drug resistance mutation among children on first-line antiretroviral therapy in Ethiopia. Method: A longitudinal study was conducted among 551 HIV-positive children (<15 years old) recruited between 2017 and 2019 at 40 antiretroviral treatment delivery sites in Ethiopia. Disease progression was retrospectively measured over a 12-year (2007-2019) follow-up as the progress towards immunosuppression. Two consecutive viral load (VL) tests were conducted in 6-month intervals to assess virologic failure (VF). For children with VF, HIV-1 genotyping and sequencing was performed for the pol gene region using in-house assay validated at the Chinese Center for Disease Control and Prevention, and the Stanford HIVDB v9.0 algorithm was used for identification of drug resistance mutations. The Kaplan-Meier analysis and Cox proportional hazards regression model were used to estimate the rate and predictors of disease progression, respectively. Results: The disease progression rate was 6.3 per 100 person-years-observation (95% CI = 4.21-8.53). Overall immunosuppression (CD4 count < 200 cells/mm3) during the 12-year follow-up was 11.3% (95% CI = 7.5-15.1). Immunosuppression was significantly increased as of the mean duration of 10.5 (95% CI = 10.1-10.8) years (38.2%) to 67.8% at 12 years (p < 0.001). Overall, 14.5% had resistance to at least one drug, and 6.2% had multi-drug resistance. A resistance of 67.8% was observed among children with VF. Resistance to non-nucleotide reverse transcriptase inhibitors (NNRTI) and nucleotide reverse transcriptase inhibitors (NRTI) drugs were 11.4% and 10.1%, respectively. Mutations responsible for NRTI resistance were M184V (30.1%), K65R (12.1%), and D67N (5.6%). Moreover, NNRTI-associated mutations were K103N (14.8%), Y181C (11.8%), and G190A (7.7%). Children who had a history of opportunistic infection [AHR (95% CI) = 3.4 (1.8-6.2)], vitamin D < 20 ng/mL [AHR (95% CI) = 4.5 (2.1-9.9)], drug resistance [AHR (95% CI) = 2.2 (1.4-3.6)], and VF [AHR (95% CI) = 2.82 (1.21, 3.53)] had a higher hazard of disease progression; whereas, being orphan [AOR (95% CI) = 1.8 (1.2-3.1)], history of drug substitution [(AOR (95% CI) = 4.8 (2.1-6.5), hemoglobin < 12 mg/dL [AOR (95% CI) = 1.2 (1.1-2.1)] had higher odds of developing drug resistance. Conclusions: Immunosuppression was increasing over time and drug resistance was also substantially high. Enhancing routine monitoring of viral load and HIVDR and providing a vitamin-D supplement during clinical management could help improve the immunologic outcome. Limiting HAART substitution is also crucial for children taking HAART in Ethiopia.

Resistance is common in paediatric patients failing ART in South Africa

BACKGROUND

Minimal data exist on HIV drug resistance patterns and prevalence among paediatric patients failing ART in resource-limited settings. We assessed levels of HIV drug resistance in children with virological failure.

METHODS

This cross-sectional study, performed from March 2017 to March 2019 in South Africa, enrolled HIV-positive children aged ≤19 years, receiving ART through public health facilities with recent evidence suggestive of virological failure (at least one viral load ≥1000 copies/mL), across 45 randomly selected high-volume clinics from all nine provinces. Resistance genotyping was performed using next-generation sequencing technologies. Descriptive analysis taking into account survey design was used to determine outcomes.

RESULTS

Among 899 participants enrolled, the adjusted proportion of HIV drug resistance among children with virological failure was 87.5% (95% CI 83.0%-90.9%). Resistance to NNRTIs was detected in 77.4% (95% CI 72.5%-81.7%) of participants, and resistance to NRTIs in 69.5% (95% CI 62.9%-75.4%) of participants. Overall, resistance to PIs was detected in 7.7% (95% CI 4.4%-13.0%) of children.

CONCLUSIONS

HIV drug resistance was highly prevalent in paediatric patients failing ART in South Africa, with 9 in 10 patients harbouring resistance to NNRTIs and/or NRTIs. PI-based regimens are predicted to be highly efficacious in achieving virological suppression amongst patients failing NNRTI-based regimens. Scaling up resistance testing amongst patients would facilitate access to second- and third-line regimens in South Africa.

Integrase inhibitors in children and adolescents: clinical use and resistance

BACKGROUND

Although integrase inhibitor (INI)-based regimens are now the first-line choice for all people living with HIV, experience among children and adolescents is still scarce. We describe the characteristics and outcomes of a paediatric/adolescent cohort on INI-based ART.

METHODS

Retrospective analysis of HIV-infected patients below 18 years of age who started an INI-based regimen from 2007 to 2019, enrolled in the Spanish National Adult (CoRIS) and Paediatric (CoRISpe) cohorts. Resistance mutations were identified by the Stanford HIV Drug Resistance Database.

RESULTS

Overall, 318 INI-based regimens were implemented in 288 patients [53.8% female; median age at start of 14.3 years (IQR 12.0-16.3)]. Most were born in Spain (69.1%), vertically infected (87.7%) and treatment-experienced (92.7%). The most frequently prescribed INI was dolutegravir (134; 42.1%), followed by raltegravir (110; 34.6%) and elvitegravir (73; 23.0%). The median exposure was 2.0 years (IQR 1.1-3.0). The main reasons to start an INI-based therapy were treatment simplification (54.4%) and virological failure (34.3%). In total, 103 (32.4%) patients interrupted their regimen: 14.5% for simplification and 8.5% due to virological failure. Most subjects who received dolutegravir (85.8%) and elvitegravir (83.6%) did not interrupt their regimen and maintained undetectable viral load. There were only five virological failures with dolutegravir and three with elvitegravir. There were no interruptions related to adverse events. Seven patients with virological failure presented major resistance mutations to INIs; none of them were on dolutegravir.

CONCLUSIONS

INI-based regimens were effective and safe for HIV treatment in children and adolescents. Dolutegravir and elvitegravir presented an excellent profile, and most patients achieved and maintained viral suppression.

Drug resistance profiles and influencing factors among HIV-infected children and adolescents receiving long-term ART: a multicentre observational study in China

OBJECTIVES

To analyse the characteristics and determinants of drug resistance mutations (DRMs) in HIV-infected children and adolescents on long-term ART in China.

METHODS

An observational cohort study was conducted in five centres. All participants younger than 15 years at ART initiation were screened, and those identified as having virological failure (VF) with viral load (VL) ≥ 400 copies/mL were included for genotypic resistance testing. Logistic regression analysis was performed and the accumulation of major mutations was analysed in a subgroup of resistant individuals with complete VL results since HIV diagnosis.

RESULTS

Among 562 eligible participants, protease and RT regions were successfully amplified for 93 who failed treatment with a median of 10.0 years ART. Sixty-eight (73.1%) harboured ≥1 major mutations. NRTI, NNRTI and dual-class resistance accounted for 48.4%, 63.4% and 38.7%, respectively. Only 3.2% were resistant to PIs. Age at ART initiation [adjusted OR (aOR) = 0.813, 95% CI 0.690-0.957], subtype B (aOR = 4.378, 95% CI 1.414-13.560) and an initial NNRTI-based regimen (aOR = 3.331, 95% CI 1.180-9.402) were independently associated with DRMs. Among 40 resistant participants with additional VL data, 55.0% had continued VF on a suboptimal regimen and the estimated duration of VF was positively correlated with the total number of major mutations (r = 0.504, P = 0.001).

CONCLUSIONS

The development of DRMs was common in children and adolescents receiving long-term treatment, and continued VF was prevalent in those with resistance. Timely genotypic testing and new child-friendly formulations are therefore urgently required.

Patterns of pretreatment drug resistance mutations of very early diagnosed and treated infants in Botswana

OBJECTIVE

To describe the occurrence of HIV drug resistance mutations (DRMs) in both intact and defective HIV-1 cell-associated DNA (HIV-1 CAD) among early-treated infants.

DESIGN

The Botswana EIT Study (ClinicalTrials.gov NCT02369406) initiated antiretroviral therapy (ART) in the first week of life and evaluated HIV-1 in plasma and peripheral blood mononuclear cells (PBMCs).

METHODOLOGY

We analyzed 257 near-HIV-1 full-length sequences (nFLS) obtained by Illumina next-generation sequencing from infants near birth. Sanger sequencing of pol was performed for mothers at delivery and children with clinical failure through 96 weeks. DRMs were identified using the Stanford HIV Drug Resistance Database.

RESULTS

In 27 infants, median PBMC HIV-1 proviral load was 492 copies/ml [IQR: 78-1246 copies/ml] at a median of 2 days (range 1-32); 18 (66.7%) had no DRMs detected; six (22.2%) had DRMs detected in defective DNA only, and three (11.1%) had DRMs in both defective and intact DNA (P = 0.09). A total of 60 of 151 (37.7%) defective sequences had at least one DRM: 31.8% NNRTI, 15.2% NRTI, 5.3% protease inhibitor, and 15.5% INSTI-associated mutations. In intact sequences, 33 of 106 (31.1%) had at least 1 DRM: 29.2% NNRTI, 7.5% NRTI, 0.9% protease inhibitor, and no INSTI-associated mutations. For all three infants with intact sequence DRMs, corresponding DRMs occurred in maternal plasma at delivery. Archived DRMs were detectable at a later clinical rebound on only one occasion.

CONCLUSION

Defective HIV-1 cell-associated DNA sequences may overestimate the prevalence of drug resistance among early-treated children. The impact of DRMs from intact proviruses on long-term treatment outcomes warrants further investigation.

Next generation sequencing based in-house HIV genotyping method: validation report

Background

HIV genotyping has had a significant impact on the care and treatment of HIV/AIDS. At a clinical level, the test guides physicians on the choice of treatment regimens. At the surveillance level, it informs policy on consolidated treatment guidelines and microbial resistance control strategies. Until recently, the conventional test has utilized the Sanger sequencing (SS) method. Unlike Next Generation Sequencing (NGS), SS is limited by low data throughput and the inability of detecting low abundant drug-resistant variants. NGS can improve sensitivity and quantitatively identify low-abundance variants; in addition, it has the potential to improve efficiency as well as lowering costs when samples are batched. Despite the NGS benefits, its utilization in clinical drug resistance profiling is faced with mixed reactions. These are largely based on a lack of a consensus regarding the quality control strategy. Nonetheless, transitional views suggest validating the method against the gold-standard SS. Therefore, we present a validation report of an NGS-based in-house HIV genotyping method against the SS method in Uganda.

Results

Since there were no established proficiency test panels for NGS-based HIV genotyping, 15 clinical plasma samples for routine care were utilized. The use of clinical samples allowed for accuracy and precision studies. The workflow involved four main steps; viral RNA extraction, targeted amplicon generation, amplicon sequencing and data analysis. Accuracy of 98% with an average percentage error of 3% was reported for the NGS based assay against the SS platform demonstrating similar performance. The coefficient of variation (CV) findings for both the inter-run and inter-personnel precision showed no variability (CV ≤ 0%) at the relative abundance of ≥ 20%. For both inter-run and inter-personnel, a variation that affected the precision was observed at 1% frequency. Overall, for all the frequencies, CV registered a small range of (0–2%).

Conclusion

The NGS-based in-house HIV genotyping method fulfilled the minimum requirements that support its utilization for drug resistance profiling in a clinical setting of a low-income country. For more inclusive quality control studies, well-characterized wet panels need to be established.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12981-021-00390-8.

Single-Agent and Fixed-Dose Combination HIV-1 Protease Inhibitor Drugs in Fission Yeast (Schizosaccharomyces pombe)

Successful combination antiretroviral therapies (cART) eliminate active replicating HIV-1, slow down disease progression, and prolong lives. However, cART effectiveness could be compromised by the emergence of viral multidrug resistance, suggesting the need for new drug discoveries. The objective of this study was to further demonstrate the utility of the fission yeast cell-based systems that we developed previously for the discovery and testing of HIV protease (PR) inhibitors (PIs) against wild-type or multi-PI drug resistant _M11PR that we isolated from an infected individual. All thirteen FDA-approved single-agent and fixed-dose combination HIV PI drugs were tested. The effect of these drugs on HIV PR activities was tested in pure compounds or formulation drugs. All FDA-approved PI drugs, except for a prodrug FPV, were able to suppress the wild-type PR-induced cellular and enzymatic activities. Relative drug potencies measured by EC₅₀ in fission yeast were discussed in comparison with those measured in human cells. In contrast, none of the FDA-approved drugs suppressed the multi-PI drug resistant _M11PR activities. Results of this study show that fission yeast is a reliable cell-based system for the discovery and testing of HIV PIs and further demonstrate the need for new PI drugs against viral multi-PI resistance.

Characterization of drug resistance and the defective HIV reservoir in virally suppressed vertically infected children in Mali

BACKGROUND

In the perspective of ART-free HIV remission, vertically infected children treated with suppressive ART from early infancy represent an optimal population model to better understand the genetic complexity of the reservoir.

OBJECTIVES

To evaluate the proportion of defective viral population and the genotypic resistance patterns in cell-associated HIV DNA.

METHODS

In a cohort including 93 ART-treated vertically HIV-infected (VHIV) children in Mali with plasma HIV-1 RNA ≤50 copies/mL for at least 6 months, we studied total HIV DNA, percentage of defective genomes and resistance by reverse transcriptase and protease bulk sequencing from whole blood in dried blood spots.

RESULTS

Children had a median age of 9.9 years at the time of inclusion (IQR = 7.6-13.4) and 3.3 years (IQR = 2-7) at ART initiation; median ART duration was 5.5 years (IQR = 3.7-7.3). The median level of total HIV DNA was 470 copies/106 cells with one patient presenting undetectable HIV DNA (<66 copies/106 cells). We observed the presence of at least one stop codon in viruses from 34 patients (37%). The presence of stop codons was not correlated with the level of HIV DNA or duration of ART. We showed a high prevalence of HIV-1 resistance in DNA with 26% of children harbouring virus resistant to at least one NRTI and 40% to at least one NNRTI.

CONCLUSIONS

While these VHIV children were successfully treated for a long time, they showed high prevalence of resistance in HIV DNA and a moderate defective HIV reservoir.

Antimicrobial Resistance Patterns of Bacterial Isolates from Blood Culture among HIV/AIDS Patients at Felege Hiwot Referral Hospital, Northwest Ethiopia

Background

The emergence and spread of antimicrobial resistance in bacteria is recognized as a global public health problem. Bloodstream infection with antimicrobial-resistant bacteria in HIV/AIDS patients makes the problem more challenging. So, regular and periodic diagnosis and use of the appropriate antimicrobial susceptibility pattern determination is the only option for decreasing the prevalence and development of drug-resistant bacteria.

Methods

An institution-based cross-sectional study was conducted among 384 HIV/AIDS patients. Sociodemographic data of patients were recorded using structured questionnaires. Blood cultures were collected with BACTEC aerobic blood culture bottles. A pair of samples was collected from each patient aseptically and incubated at 37°. If samples are positive for bacterial agents, they were subcultured to solid media such as blood agar plate, chocolate agar plate, and MacConkey agar plates. Identification was performed using colony characteristics and standard biochemical techniques. The antimicrobial susceptibility test was determined by the Kirby–Bauer disc diffusion method. Data entry and analysis were performed while using SPSS version 20. Descriptive statistics were performed to calculate frequencies.

Results

Altogether, 384 patients were included, and 123 blood cultures were positive, so that the yield was thus 32%. About 46 (37.4%) of Gram-negative and 77 (62.6%) of Gram-positive bacterial species were identified. Among Gram-negative bacterial isolates, K. pneumoniae was the leading pathogen, 19 (41.3%), whereas S. aureus, 38 (49.4%), was predominant among Gram-positive isolates. In his study, the majority of Gram-positive isolates showed high level of resistance to penicillin, 72 (95.5%), tetracycline, 55 (71.4%), and cotrimoxazole, 45 (58.4%). About 28 (73.6%) of S. aureus isolates were also methicillin-resistant. Gram-negative bacterial isolates also showed a high resistance to ampicillin (91.3%), tetracycline (91.3%), and gentamicin (47.8%). Overall, about 78% of multidrug resistance was observed.

Conclusion

Several pathogens were resistant to greater than five antimicrobial agents, so that proper management of patients with bacteremia is needed, and a careful selection of effective antibiotics should be practiced.

Virological outcome among HIV infected patients transferred from pediatric care to adult units in Madrid, Spain (1997-2017)

The aim of this transversal study was to describe the virological and immunological features of HIV-infected youths transferred from pediatric to adult care units since 1997 vs. the non-transferred patients from the Madrid Cohort of HIV-infected children and adolescents in Spain. We included 106 non-transferred and 184 transferred patients under clinical follow-up in 17 public hospitals in Madrid by the end of December 2017. Virological and immunological outcomes were compared in transferred vs. non-transferred patients. ART drug resistance mutations and HIV-variants were analyzed in all subjects with available resistance pol genotypes and/or genotypic resistance profiles. Among the study cohort, 133 (72.3%) of 184 transferred and 75 (70.7%) of 106 non-transferred patients had available resistance genotypes. Most (88.9%) of transferred had ART experience at sampling. A third (33.3%) had had a triple-class experience. Acquired drug resistance (ADR) prevalence was significantly higher in pretreated transferred than non-transferred patients (71.8% vs. 44%; p = 0.0009), mainly to NRTI (72.8% vs. 31.1%; p < 0.0001) and PI (29.1% vs. 12%; p = 0.0262). HIV-1 non-B variants were less frequent in transferred vs. non-transferred (6.9% vs. 32%; p < 0.0001). In conclusion, the frequent resistant genotypes found in transferred youths justifies the reinforcement of HIV resistance monitoring after the transition to avoid future therapeutic failures.

Pre-treatment drug resistance and HIV-1 subtypes in infants from Argentina with and without exposure to antiretroviral drugs for prevention of mother-to-child transmission

OBJECTIVES

To assess the prevalence and patterns of pre-treatment HIV drug resistance (PDR) and HIV-1 subtype in infants from Argentina with exposure to different antiretroviral drugs (ARVs) for the prevention of mother-to-child transmission (PMTCT).

PATIENTS AND METHODS

HIV-1 genotyping was performed in 115 infants (median age = 2.3 months) born between 2007 and 2014 to screen for drug resistance mutations (DRMs) before starting first-line ART. HIV-1 subtype was characterized by phylogenetic and recombination analysis.

RESULTS

Overall, DRMs were found in 34 of 115 infants (PDR level 30% to any ARV, 3.5% to PIs, 12% to NRTIs and 22% to NNRTIs). Of the 115 infants, 22 (19.1%) were ARV-unexposed. Another 93 were ARV-exposed: 28 (24.3%) to short-course zidovudine monotherapy ARV prophylaxis; 25 (21.7%) to nevirapine-based ARV prophylaxis; 12 (10.4%) to perinatal infant zidovudine prophylaxis + maternal combination ART with NNRTIs; and 28 (24.3%) to perinatal infant zidovudine prophylaxis+maternal combination ART with PIs. Transmitted drug resistance among ARV-unexposed infants was 32% (5% to PIs, 9% to NRTIs and 18% to NNRTIs). ART-exposed infants showed multi-class ARV resistance. Importantly, vertical transmission of a triple-class-resistant virus was confirmed in one case. Patterns of DRMs predicted high-level resistance to NNRTIs in a similar and high proportion (>50%) of infants with at least one DRM independently of ARV exposure. BF recombinants were found in 74%, subtype B in 20%, subtype C in 3% and novel AG and AB recombinants in 3%.

CONCLUSIONS

PDR in HIV-1-infected children from Argentina is among the highest reported, jeopardizing successful lifelong suppressive ART as well as the efficacy of current PMTCT regimens.

Scaffold Simplification Strategy Leads to a Novel Generation of Dual Human Immunodeficiency Virus and Enterovirus-A71 Entry Inhibitors

Currently, there are only three FDA-approved drugs that inhibit human immunodeficiency virus (HIV) entry-fusion into host cells. The situation is even worse for enterovirus EV71 infection for which no antiviral therapies are available. We describe here the discovery of potent entry dual inhibitors of HIV and EV71. These compounds contain in their structure three or four tryptophan (Trp) residues linked to a central scaffold. Critical for anti-HIV/EV71 activity is the presence of extra phenyl rings, bearing one or two carboxylates, at the C2 position of the indole ring of each Trp residue. The most potent derivatives, 22 and 30, inhibit early steps of the replicative cycles of HIV-1 and EV-A71 by interacting with their respective viral surfaces (glycoprotein gp120 of HIV and the fivefold axis of the EV-A71 capsid). The high potency, low toxicity, facile chemical synthesis, and great opportunities for chemical optimization make them useful prototypes for future medicinal chemistry studies.

Virological failure in children living with HIV on antiretroviral therapy: correlates and predictive value of clinical measurements and CD4 cell count

Clinical correlates and CD4 cell count are used to predict HIV virological failure among children living with HIV in resource-limited settings, but there are limited data on their prediction of treatment failure compared to viral measurement. Using HIV viral load as a gold standard, sensitivity and specificity of longitudinal CD4 responses and clinical changes were defined in children living with HIV on antiretroviral therapy (ART) for ≥6 months in Kenya. Prevalence and correlates of virological failure were determined using log-binomial regression with robust standard error. Among 223 children who were followed for 12 months, median age in years at HIV diagnosis, ART initiation, and study enrollment were 3.3, 3.6, and 7.5, respectively. Older children at HIV diagnosis and ART initiation were less likely to experience virological failure. Immunological and clinical failure had low sensitivity (0 and 2%, respectively) to identify virological failure. Among those with virological failure, there was no indication from immunological markers and only two (2%) indicated with clinical markers. Clinical and immunological monitoring of HIV were insensitive and poor predictors of virological failure, emphasizing the importance of routine virological monitoring to inform ART treatment decisions for children living with HIV.

Rates and Correlates of Short Term Virologic Response among Treatment-Naïve HIV-Infected Children Initiating Antiretroviral Therapy in Ethiopia: A Multi-Center Prospective Cohort Study

There is limited data on virologic outcome and its correlates among HIV-infected children in resource-limited settings. We investigated rate and correlates of virologic outcome among treatment naïve HIV-infected Ethiopian children initiating cART, and were followed prospectively at baseline, 8, 12, 24 and 48 weeks using plasma viral load, clinical examination, laboratory tests and pretreatment HIV drug resistance (PDR) screening. Virologic outcome was assessed using two endpoints–virological suppression defined as having “undetectable” plasma viral load < 150 RNA copies/mL, and rebound defined as viral load ≥150 copies/mL after achieving suppression. Cox Proportional Hazards Regression was employed to assess correlates of outcome. At the end of follow up, virologic outcome was measured for 110 participants. Overall, 94(85.5%) achieved virological suppression, of which 36(38.3%) experienced virologic rebound. At 48 weeks, 9(8.2%) children developed WHO-defined virological treatment failure. Taking tenofovir-containing regimen (Hazard Ratio (HR) 3.1-[95% confidence interval (95%CI) 1.0–9.6], p = 0.049) and absence of pretreatment HIV drug resistance (HR 11.7-[95%CI 1.3–104.2], p = 0.028) were independently associated with earlier virologic suppression. In conclusion, PDR and cART regimen type correlate with rate of virologic suppression which was prominent during the first year of cART initiation. However, the impact of viral rebound in 38.3% of the children needs evaluation.

Molecular Antiretroviral Resistance Markers of Human Immunodeficiency Virus-1 of CRF01_AE Subtype in Bali, Indonesia

Background:

Molecular epidemiological study of human immunodeficiency virus drug-resistant (HIVDR) markers is challenging in areas where the dominant subtype is non-B.

Objective:

Here we provide molecular data for HIVDR in the CRF01_AE subtype in Bali, Indonesia.

Method:

Seventy patients were enrolled in this study and grouped into treatment failure and treatment naïve groups. The full-length pol gene was amplified using nested reverse transcriptase polymerase chain reaction and the product was then sequenced. The readable sequence was then subjected to Stan-ford HIV Drug Resistance Database genotyping.

Results:

We found that clinical classification was in accordance with the presence of HIVDR markers in the pol gene. Independent of therapy history, the treatment failure group showed resistance markers against nucleoside reverse transcriptase inhibitors (NRTI) and non-nucleoside reverse transcriptase in-hibitors (NNRTI), ranging from 72%–100% of patients. Only a small proportion of naïve patients harbored HIV with drug resistance markers to NNRTI. No protease inhibitor-resistant marker was found in either patient group. Molecular marker mutations, which were found in more than 50% of treatment failure patients, were M184V (100%), T215A/Y/F (88.2%), D67N/G (76.5%), and M41L (58.8%).

Conclusion:

The protocol used in this study to determine genetic markers of HIVDR based on sub-type B can be applied for the rapid determination of resistance of the CRF01_AE subtype. All patients with progressive clinical signs and increased viral load should be recommended to undergo second-line treatment of the ARV regimen.

Modifications in the branched arms of a class of dual inhibitors of HIV and EV71 replication expand their antiviral spectrum

We have previously reported a new class of dendrimers with tryptophan (Trp) residues on the surface that show dual antiviral activities against HIV and enterovirus EV71. The prototype compound of this family is a derivative of pentaerythritol with 12 peripheral Trp groups and trivalent spacer arms. Here a novel series of dendrimers with divalent and tetravalent branched arms, instead of the trivalent ones present on the prototype, has been synthesized and its activity against HIV, EV71 and a panel of 16 different viruses and other pathogens has been determined. Convergent or divergent approaches have been used for the synthesis of these compounds. Our findings demonstrate that only compounds with tetravalent branched arms showed the same anti-HIV and anti-EV71 activity of the prototype (low micromolar) and even gain significant antiviral activity against new pathogens such as HSV-2, adenovirus-2, human corona virus and respiratory syncytial virus, being the first members of the Trp dendrimer family that showed activity against those viruses. As the prototype, these compounds also showed low-nanomolar activity against a representative EV71 clinical isolate. Experimental work carried on to determine the mode of action of the most potent IIa, containing tetravalent branched arms, demonstrated that it interacts with the viral envelopes of HIV, EV71 and HSV-2 and thus may prevent virus attachment to the host cell. These results support the interest of this new series of Trp dendrimers and qualify them as useful prototypes for the development of novel inhibitors of viral entry with broad antiviral spectrum.

•

Tryptophan (Trp) dendrimers with divalent and tetravalent branched arms have been synthesized.

•

Only dendrimers with tetravalent branched arms (IIa-IId) showed (sub)micromolar inhibitory activity against HIV and EV71.

•

IIa-IId inhibit a representative EV71 clinical isolate in the low-nanomolar range.

•

IIa-IId are the first members of the Trp dendrimer family that showed activity against new viruses such as HSV-2.

Antiretroviral resistance testing in HIV-positive people

BACKGROUND

Resistance to antiretroviral therapy (ART) among people living with human immunodeficiency virus (HIV) compromises treatment effectiveness, often leading to virological failure and mortality. Antiretroviral drug resistance tests may be used at the time of initiation of therapy, or when treatment failure occurs, to inform the choice of ART regimen. Resistance tests (genotypic or phenotypic) are widely used in high-income countries, but not in resource-limited settings. This systematic review summarizes the relative merits of resistance testing in treatment-naive and treatment-exposed people living with HIV.

OBJECTIVES

To evaluate the effectiveness of antiretroviral resistance testing (genotypic or phenotypic) in reducing mortality and morbidity in HIV-positive people.

SEARCH METHODS

We attempted to identify all relevant studies, regardless of language or publication status, through searches of electronic databases and conference proceedings up to 26 January 2018. We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), and ClinicalTrials.gov to 26 January 2018. We searched Latin American and Caribbean Health Sciences Literature (LILACS) and the Web of Science for publications from 1996 to 26 January 2018.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) and observational studies that compared resistance testing to no resistance testing in people with HIV irrespective of their exposure to ART.Primary outcomes of interest were mortality and virological failure. Secondary outcomes were change in mean CD4-T-lymphocyte count, clinical progression to AIDS, development of a second or new opportunistic infection, change in viral load, and quality of life.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed each reference for prespecified inclusion criteria. Two review authors then independently extracted data from each included study using a standardized data extraction form. We analysed data on an intention-to-treat basis using a random-effects model. We performed subgroup analyses for the type of resistance test used (phenotypic or genotypic), use of expert advice to interpret resistance tests, and age (children and adolescents versus adults). We followed standard Cochrane methodological procedures.

MAIN RESULTS

Eleven RCTs (published between 1999 and 2006), which included 2531 participants, met our inclusion criteria. All of these trials exclusively enrolled patients who had previous exposure to ART. We found no observational studies. Length of follow-up time, study settings, and types of resistance testing varied greatly. Follow-up ranged from 12 to 150 weeks. All studies were conducted in Europe, USA, or South America. Seven studies used genotypic testing, two used phenotypic testing, and two used both phenotypic and genotypic testing. Only one study was funded by a manufacturer of resistance tests.Resistance testing made little or no difference in mortality (odds ratio (OR) 0.89, 95% confidence interval (CI) 0.36 to 2.22; 5 trials, 1140 participants; moderate-certainty evidence), and may have slightly reduced the number of people with virological failure (OR 0.70, 95% CI 0.56 to 0.87; 10 trials, 1728 participants; low-certainty evidence); and probably made little or no difference in change in CD4 cell count (mean difference (MD) -1.00 cells/mm³, 95% CI -12.49 to 10.50; 7 trials, 1349 participants; moderate-certainty evidence) or progression to AIDS (OR 0.64, 95% CI 0.31 to 1.29; 3 trials, 809 participants; moderate-certainty evidence). Resistance testing made little or no difference in adverse events (OR 0.89, 95% CI 0.51 to 1.55; 4 trials, 808 participants; low-certainty evidence) and probably reduced viral load (MD -0.23, 95% CI -0.35 to -0.11; 10 trials, 1837 participants; moderate-certainty evidence). No studies reported on development of new opportunistic infections or quality of life. We found no statistically significant heterogeneity for any outcomes, and the I² statistic value ranged from 0 to 25%. We found no subgroup effects for types of resistance testing (genotypic versus phenotypic), the addition of expert advice to interpretation of resistance tests, or age. Results for mortality were consistent when we compared studies at high or unclear risk of bias versus studies at low risk of bias.

AUTHORS' CONCLUSIONS

Resistance testing probably improved virological outcomes in people who have had virological failure in trials conducted 12 or more years ago. We found no evidence in treatment-naive people. Resistance testing did not demonstrate important patient benefits in terms of risk of death or progression to AIDS. The trials included very few participants from low- and middle-income countries.

Impact of Clinical Parameters in the Intrahost Evolution of HIV-1 Subtype B in Pediatric Patients: A Machine Learning Approach

Determining the factors modulating the genetic diversity of HIV-1 populations is essential to understand viral evolution. This study analyzes the relative importance of clinical factors in the intrahost HIV-1 subtype B (HIV-1B) evolution and in the fixation of drug resistance mutations (DRM) during longitudinal pediatric HIV-1 infection. We recovered 162 partial HIV-1B pol sequences (from 3 to 24 per patient) from 24 perinatally infected patients from the Madrid Cohort of HIV-1 infected children and adolescents in a time interval ranging from 2.2 to 20.3 years. We applied machine learning classification methods to analyze the relative importance of 28 clinical/epidemiological/virological factors in the HIV-1B evolution to predict HIV-1B genetic diversity (d), nonsynonymous and synonymous mutations (dN, dS) and DRM presence. Most of the 24 HIV-1B infected pediatric patients were Spanish (91.7%), diagnosed before 2000 (83.3%), and all were antiretroviral therapy experienced. They had from 0.3 to 18.8 years of HIV-1 exposure at sampling time. Most sequences presented DRM. The best-predictor variables for HIV-1B evolutionary parameters were the age of HIV-1 diagnosis for d, the age at first antiretroviral treatment for dN and the year of HIV-1 diagnosis for ds. The year of infection (birth year) and year of sampling seemed to be relevant for fixation of both DRM at large and, considering drug families, to protease inhibitors (PI). This study identifies, for the first time using machine learning, the factors affecting more HIV-1B pol evolution and those affecting DRM fixation in HIV-1B infected pediatric patients.

Trends in Drug Resistance Prevalence, HIV-1 Variants and Clinical Status in HIV-1-infected Pediatric Population in Madrid: 1993 to 2015 Analysis

BACKGROUND

The expanded use of long-term antiretroviral treatments in infected children may exacerbate the problem of drug resistance mutations selection, which can compromise treatment efficiency.

OBJECTIVE

We describe the temporal trends of HIV drug resistance mutations and the HIV-1 variants during 23 years (1993 to March 2016) in the Madrid cohort of HIV-infected children and adolescents.

METHODS

We selected patients with at least one available HIV-1 pol sequence/genotypic resistance profile, establishing different groups according to the sampling year of first resistance data. We determined the prevalence of transmitted drug resistance mutations or acquired drug resistance mutations (DRM), the drug susceptibility among resistant viruses and HIV-1 variants characterized by phylogeny across time.

RESULTS

A total of 245 pediatric patients were selected, being mainly female, Spanish native, perinatally infected and carrying HIV-1 subtype B. At first sampling, most pediatric patients were on antiretroviral therapy and heavily pretreated. During 1993 to 2016, transmitted drug resistance mutations was found in 13 (26%) of 50 naive children [non-nucleoside reverse transcriptase inhibitors (NNRTI), 14.6%; nucleoside reverse transcriptase inhibitors (NRTI), 10.4%; protease inhibitors, 8.7%]. DRM appeared in 139 (73.2%) of 190 pretreated patients (NRTI, 64.5%; NNRTI, 36%; protease inhibitors, 35.1%). DRM to NNRTI was higher in last 5 years. Non-B variants infected 14.5% of children and adolescents of the Madrid Cohort, being mainly intersubtype recombinants (76.5%), including complex unique recombinant strains. They caused 3.4% infections before 2000, rising to 85.7% during 2011 to 2016.

CONCLUSIONS

Periodic surveillance resistance and molecular epidemiology studies in long-term pretreated HIV-infected pediatric populations are required to optimize treatment regimens. Results will permit a better understanding of long-time dynamics of viral resistance and HIV-1 variants in Spain.

Effect of HIV/HCV Co-Infection on the Protease Evolution of HIV-1B: A Pilot Study in a Pediatric Population

This pilot study evaluates in pediatric patients the impact of HIV/HCV coinfection in the molecular evolution of the HIV-1 subtype B protease (HIV-1BPR). For this study, HIV-1B/HCV coinfected (15) and HIV-1B monoinfected (56) patients with available HIV-1B pol sequences were enrolled. Both groups of patients had comparable gender frequencies and average age, time of infection, antiretroviral treatment (ART) exposure and time under ART. Prevalence of drug resistance mutations (DRM), genetic diversity, number of synonymous (d_S) and non-synonymous (d_N) mutations per site and selection pressures (d_N - d_S) in the HIV-1BPR were estimated and compared between mono- and coinfected patients. Both HIV-1B populations presented similar genetic diversity (0.050 ± 0.02 vs. 0.045 ± 0.01) and d_S (0.074 ± 0.03 vs. 0.078 ± 0.04). In turn, in coinfected patients the HIV-1BPR had higher d_N (0.045 ± 0.01 vs. 0.024 ± 0.01) and d_N-d_S (-0.026 ± 0.02 vs. -0.048 ± 0.04) values, and less amino acid sites under purifying selection (4.2% vs. 42.1%) than in monoinfected patients. Accordingly, in co-infection with HCV, the HIV-1BPR sites 50, 53, 82, 84 and 88 - associated with resistance to PIs - were under neutral evolution, whereas these sites were under purifying selection in monoinfected patients. This pilot study suggests that HIV-1B may evolve differently in the presence than in the absence of HCV.

Drug resistance in antiretroviral-naive children newly diagnosed with HIV-1 in Manaus, Amazonas

Objectives

To determine the prevalence of drug resistance mutations (DRM), the prevalence of drug susceptibility [transmitted drug resistance (TDR)] and the prevalence of HIV-1 variants among treatment-naive HIV-infected children in Manaus, Amazonas state, Brazil.

Methods

Children born to HIV-infected mothers and diagnosed with HIV in an HIV reference service centre and with available pol sequence between 2010 and 2015 prior to antiretroviral initiation were included. TDR was identified using the Calibrated Population Resistance Tool. HIV-1 subtypes were defined by Rega and phylogenetic analyses.

Results

One hundred and seventeen HIV-infected children with a median age of 3.7 years were included. Among them, 28.2% had been exposed to some form of prevention of mother-to-child transmission (PMTCT). HIV DRM were present in 21.4% of all children. Among PMTCT-exposed children, 3% had NRTI mutations, 15.2% had NNRTI mutations and 3% had PI mutations. Among PMTCT-unexposed children, 1.2% had NRTI mutations, 21.4% had non-NNRTI mutations and 1.2% had PI mutations. The most common DRM was E138A (8.5%). The prevalence of TDR was 16.2%; 21.1% among PMTCT-exposed children and 14.3% among PMTC-unexposed children. The analysis of HIV-1 subtypes revealed that 80.2% were subtype B, 6.0% were subtype C, 3.4% were subtype F1 and 10.3% were possible unique recombinant forms (BF1, 4.3%; DB, 4.3%; BC, 0.9%; KC, 0.9%).

Conclusions

We report a high prevalence of DRM in this population, including in almost a quarter of children with no reported PMTCT. The high prevalence of TDR observed might compromise ART effectiveness. Results show extensive HIV-1 diversity and expansion of subtype C, which highlights the need for surveillance of HIV-1 subtypes in Amazonas state.

Recent advances in pharmacological research on Ecklonia species: a review

The genus Ecklonia (Lessoniaceae, Phaeophyceae), commonly called kelp (brown algae), is abundant on the coasts of Japan and Korea. During the past few decades, Ecklonia species have received tremendous attention for their wide range of therapeutic properties and multiple health benefits, such as great nutritional value and being rich in vitamins, minerals, dietary fiber, proteins, and polysaccharides. Several novel functional ingredients with diversified biological activities have been isolated and possess antimicrobial, antiviral, hepatoprotective, cardioprotective, anti-inflammatory, neuroprotective, anticarcinogenic, immunomodulatory, hypolipidemic, anti-diabetic, and antioxidant therapeutic properties. The present review discusses the phytochemical, pharmacological, therapeutic, nutritional, and health benefits of different species of genus Ecklonia, as well as their use in the prevention of disease and maintenance of good health.

HIV drug resistance in infants increases with changing prevention of mother-to-child transmission regimens

OBJECTIVES

The objectives of this study were to determine HIV drug resistance (HIVDR) prevalence in Zambian infants upon diagnosis, and to determine how changing prevention of mother-to-child transmission (PMTCT) drug regimens affect drug resistance.

DESIGN

Dried blood spot (DBS) samples from infants in the Lusaka District of Zambia, obtained during routine diagnostic screening, were collected during four different years representing three different PMTCT drug treatment regimens.

METHODS

DNA extracted from dried blood spot samples was used to sequence a 1493 bp region of the reverse transcriptase gene. Sequences were analyzed via the Stanford HIVDRdatabase (http://hivdb.standford.edu) to screen for resistance mutations.

RESULTS

HIVDR in infants increased from 21.5 in 2007/2009 to 40.2% in 2014. Nonnucleoside reverse transcriptase inhibitor resistance increased steadily over the sampling period, whereas nucleoside reverse transcriptase inhibitor resistance and dual class resistance both increased more than threefold in 2014. Analysis of drug resistance scores in each group revealed increasing strength of resistance over time. In 2014, children with reported PMTCT exposure, defined as infant prophylaxis and/or maternal treatment, showed a higher prevalence and strength of resistance compared to those with no reported exposure.

CONCLUSION

HIVDR is on the rise in Zambia and presents a serious problem for the successful lifelong treatment of HIV-infected children. PMTCT affects both the prevalence and strength of resistance and further research is needed to determine how to mitigate its role leading to resistance.

HIV-1 Subtype Diversity and Prevalence of Primary Drug Resistance in a Single-Center Pediatric Cohort in Germany

OBJECTIVES

Data on drug-resistant mutations (DRMs) in HIV-1-infected therapy-naïve children are scarce. The aim of this study was to determine the HIV-1 subtype distribution and the prevalence of DRMs in therapy-naïve HIV-1-infected children who received routine care at the University Hospital Düsseldorf, Düsseldorf, Germany.

METHODS

Records of all HIV-1-infected children who received routine care between January 2005 and December 2015 were analyzed retrospectively. The collected data included demographics, clinical characteristics, CD4 cell count, viral load, HIV-1 subtype, and resistance genotype at baseline.

RESULTS

83 HIV-1-infected children received routine care during the observation period. HIV-1 subtypes were available in 61/83 patients (73.5%) and baseline HIV-1 resistance in 24 (29%). The prevalence of major DRMs was 29% (21% nucleoside reverse-transcriptase inhibitors [NRTIs], 12.5% non-NRTIs, and 4% protease inhibitors). Minor mutations in the protease gene were common (58%). Non-B subtypes were predominant (77%).

CONCLUSIONS

We report a predominance of non-subtype-B infections and a higher prevalence of DRMs compared to other pediatric cohorts from resource-rich settings. The difference in HIV-1 subtype distribution is due to the fact that a relevant proportion of pediatric patients in Germany are immigrants from high-prevalence settings in sub-Saharan Africa where non-B subtypes predominate.

Impact of lopinavir-ritonavir exposure in HIV-1 infected children and adolescents in Madrid, Spain during 2000-2014

Background

The most-used protease-inhibitor in children is Lopinavir-ritonavir (LPV/r), which provides durable suppression of viral load and increases CD4+T-counts. This study describes the virological outcome of the HIV-1-infected paediatric population exposed to LPV/r during 15 years in Spain.

Methodology

Patients from the Madrid Cohort of HIV-1-infected-children and adolescents exposed to LPV/r as different line therapy during 2000–2014 were selected. The baseline epidemiological-clinical features, viral suppression, changes in CD4+T-CD8+T cell counts and drug susceptibility were recorded before and during LPV/r exposure. Drug resistance mutations (DRM) were identified in viruses from samples collected until 2011. We predicted drug susceptibility to 19 antiretrovirals among those carrying DRM using the Stanford′s HIVdb Algorithm.

Results

A total of 199 (37.3%) of the 534 patients from the cohort were exposed to LPV/r during 2000–2014 in first (group 1), second (group 2) or more line-therapies (group 3). Patients were mainly Spaniards (81.9%), perinatally infected (96.5%) with subtype-B (65.3%) and HIV-diagnosed before year 2000 (67.8%). The mean age at first LPV/r exposure was 9.7 years. After protease-inhibitor exposure, viral suppression was higher in groups 1 and 2 than in group 3. Viral suppression occurred in 87.5%, 68.6% and 64.8% patients from groups 1, 2 and 3, respectively. Among the 64 patients with available resistance data during LPV/r treatment, 27(42.3%) carried DRM to protease-inhibitor, 28 (58.3%) to reverse-transcriptase-inhibitors and 21 (43.7%) to non-reverse-transcriptase-inhibitors. Darunavir/ritonavir, atazanavir-ritonavir and tipranavir/ritonavir presented the highest susceptibility and nelfinavir the lowest.

Conclusions

A better lymphocyte recovering occurred when protease-inhibitor was taken as part of a first-line regimen and a higher number of patients reached viral suppression. The least compromised antiretrovirals for rescue antiretroviral regimens, according to DRM in the LPV/r-exposed-paediatric cohort, were mainly the new protease inhibitors.

A fission yeast cell-based system for multidrug resistant HIV-1 proteases

Background

HIV-1 protease (PR) is an essential enzyme for viral production. Thus, PR inhibitors (PIs) are the most effective class of anti-HIV drugs. However, the main challenge to the successful use of PI drugs in patient treatment is the emergence of multidrug resistant PRs (_mdrPRs). This study aimed to develop a fission yeast cell-based system for rapid testing of new PIs that combat _mdrPRs.

Results

Three _mdrPRs were isolated from HIV-infected patients that carried seven (_M7PR), ten (_M10PR) and eleven (_M11PR) PR gene mutations, respectively. They were cloned and expressed in fission yeast under an inducible promoter to allow the measurement of PR-specific proteolysis and drug resistance. The results showed that all three _mdrPRs maintained their abilities to proteolyze HIV viral substrates (MA↓CA and p6) and to confer drug resistance. Production of these proteins in the fission yeast caused cell growth inhibition, oxidative stress and altered mitochondrial morphologies that led to cell death. Five investigational PIs were used to test the utility of the established yeast system with an FDA-approved PI drug Darunavir (DRV) as control. All six compounds suppressed the wildtype PR (_wtPR) and the _M7PR-mediated activities. However, none of them were able to suppress the _M10PR or the _M11PR.

Conclusions

The three clinically isolated _mdrPRs maintained their viral proteolytic activities and drug resistance in the fission yeast. Furthermore, those viral _mdrPR activities were coupled with the induction of growth inhibition and cell death, which could be used to test the PI activities. Indeed, the five investigational PIs and DRV suppressed the _wtPR in fission yeast as they did in mammalian cells. Significantly, two of the high level _mdrPRs (_M10PR and _M11PR) were resistant to all of the existing PI drugs including DRV. This observation underscores the importance of continued searching for new PIs against _mdrPRs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13578-016-0131-5) contains supplementary material, which is available to authorized users.

Structure-activity relationship studies on a Trp dendrimer with dual activities against HIV and enterovirus A71. Modifications on the amino acid

We have recently described a new class of dendrimers with tryptophan (Trp) on the surface that show dual antiviral activities against HIV and EV71 enterovirus. The prototype compound of this family is a pentaerythritol derivative with 12 Trps on the periphery. Here we complete the structure-activity relationship studies of this family to identify key features that might be significant for the antiviral activity. With this aim, novel dendrimers containing different amino acids (aromatic and non-aromatic), tryptamine (a "decarboxylated" analogue of Trp) and N-methyl Trp on the periphery have been prepared. Dendrimer with N-Methyl Trp was the most active against HIV-1 and HIV-2 while dendrimer with tyrosine was endowed with the most potent antiviral activity against EV71. This tyrosine dendrimer proved to inhibit a large panel of EV71 clinical isolates (belonging to different clusters) in the low nanomolar/high picomolar range. In addition, a new synthetic procedure (convergent approach) has been developed for the synthesis of the prototype and some other dendrimers. This convergent approach proved more efficient (higher yields, easier purification) than the divergent approach previously reported.

Alarming increase in pretreatment HIV drug resistance in children living in sub-Saharan Africa: a systematic review and meta-analysis

BACKGROUND

Children have an augmented risk of pretreatment HIV drug resistance (PDR) due to exposure to antiretroviral drugs for the prevention of mother-to-child transmission (PMTCT). Paediatric data are essential to evaluate the effectiveness of the restricted number of paediatric regimens currently available, but these data are scarce.

METHODS

We conducted a systematic review of the literature on PDR in children (median age ≤12 years) in sub-Saharan Africa. We separately extracted the proportion of children with PDR for children with and without prior PMTCT exposure, used random-effects meta-analysis to pool proportions and used meta-regression to assess subgroup differences.

RESULTS

We included 19 studies representing 2617 children from 13 countries. The pooled PDR prevalence was 42.7% (95% CI 26.2%-59.1%) among PMTCT-exposed children and 12.7% (95% CI 6.7%-18.7%) among PMTCT-unexposed children (P = 0.004). The PDR prevalence in PMTCT-unexposed children increased from 0% in 2004 to 26.8% in 2013 (P = 0.009). NNRTI mutations were detected in 32.4% (95% CI 18.7%-46.1%) of PMTCT-exposed children and in 9.7% (95% CI 4.6%-14.8%) of PMTCT-unexposed children; PI mutations were uncommon (<2.5%). PDR was more common in children aged <3 years compared with children aged ≥3 years [40.9% (95% CI 27.6%-54.3%) versus 17.6% (95% CI 8.9%-26.3%), respectively (P = 0.025)].

CONCLUSIONS

The PDR prevalence in African children is high and rapidly increasing. Even in PMTCT-unexposed children, the most recent reports indicate that PDR is present in up to a third of children starting first-line therapy. Our data underscore the importance of initiating PI-based first-line ART in young children (<3 years of age) and suggest that older children may also benefit from this approach.

Clinical Determinants of HIV-1B Between-Host Evolution and their Association with Drug Resistance in Pediatric Patients

Understanding the factors that modulate the evolution of virus populations is essential to design efficient control strategies. Mathematical models predict that factors affecting viral within-host evolution may also determine that at the between-host level. Although HIV-1 within-host evolution has been associated with clinical factors used to monitor AIDS progression, such as patient age, CD4 cells count, viral load, and antiretroviral experience, little is known about the role of these clinical factors in determining between-host HIV-1 evolution. Moreover, whether the relative importance of such factors in HIV-1 evolution vary in adult and children patients, in which the course of infection is different, has seldom been analysed. To address these questions, HIV-1 subtype B (HIV-1B) pol sequences of 163 infected children and 450 adults of Madrid, Spain, were used to estimate genetic diversity, rates of synonymous and non-synonymous mutations, selection pressures and frequency of drug-resistance mutations (DRMs). The role and relative importance of patient age, %CD4, CD4/mm3, viral load, and antiretroviral experience in HIV-1B evolution was analysed. In the pediatric HIV-1B population, three clinical factors were primary predictors of virus evolution: Higher HIV-1B genetic diversity was observed with increasing children age, decreasing CD4/mm3 and upon antiretroviral experience. This was mostly due to higher rates of non-synonymous mutations, which were associated with higher frequency of DRMs. Using this data, we have also constructed a simple multivariate model explaining between 55% and 66% of the variance in HIV-1B evolutionary parameters in pediatric populations. On the other hand, the analysed clinical factors had little effect in adult-infecting HIV-1B evolution. These findings highlight the different evolutionary dynamics of HIV-1B in children and adults, and contribute to understand the factors shaping HIV-1B evolution and the appearance of drug-resistance mutation in pediatric patients.

High levels of pre-treatment HIV drug resistance and treatment failure in Nigerian children

Introduction

Pre-treatment HIV drug resistance (PDR) is an increasing problem in sub-Saharan Africa. Children are an especially vulnerable population to develop PDR given that paediatric second-line treatment options are limited. Although monitoring of PDR is important, data on the paediatric prevalence in sub-Saharan Africa and its consequences for treatment outcomes are scarce. We designed a prospective paediatric cohort study to document the prevalence of PDR and its effect on subsequent treatment failure in Nigeria, the country with the second highest number of HIV-infected children in the world.

Methods

HIV-1-infected children ≤12 years, who had not been exposed to drugs for the prevention of mother-to-child transmission (PMTCT), were enrolled between 2012 and 2013, and followed up for 24 months in Lagos, Nigeria. Pre-antiretroviral treatment (ART) population-based pol genotypic testing and six-monthly viral load (VL) testing were performed. Logistic regression analysis was used to assess the effect of PDR (World Health Organization (WHO) list for transmitted drug resistance) on subsequent treatment failure (two consecutive VL measurements >1000 cps/ml or death).

Results

Of the total 82 PMTCT-naïve children, 13 (15.9%) had PDR. All 13 children harboured non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations, of whom seven also had nucleoside reverse transcriptase inhibitor resistance. After 24 months, 33% had experienced treatment failure. Treatment failure was associated with PDR and a higher log VL before treatment initiation (adjusted odds ratio (aOR) 7.53 (95%CI 1.61–35.15) and 2.85 (95%CI 1.04–7.78), respectively).

Discussion

PDR was present in one out of six Nigerian children. These high numbers corroborate with recent findings in other African countries. The presence of PDR was relevant as it was the strongest predictor of first-line treatment failure.

Conclusions

Our findings stress the importance of implementing fully active regimens in children living with HIV. This includes the implementation of protease inhibitor (PI)-based first-line ART, as is recommended by the WHO for all HIV-infected children <3 years of age. Overcoming practical barriers to implement PI-based regimens is essential to ensure optimal treatment for HIV-infected children in sub-Saharan Africa. In countries where individual VL or resistance testing is not possible, more attention should be given to paediatric PDR surveys.

Prevalence and effect of pre-treatment drug resistance on the virological response to antiretroviral treatment initiated in HIV-infected children - a EuroCoord-CHAIN-EPPICC joint project

Background

Few studies have evaluated the impact of pre-treatment drug resistance (PDR) on response to combination antiretroviral treatment (cART) in children. The objective of this joint EuroCoord-CHAIN-EPPICC/PENTA project was to assess the prevalence of PDR mutations and their association with virological outcome in the first year of cART in children.

Methods

HIV-infected children <18 years initiating cART between 1998 and 2008 were included if having at least one genotypic resistance test prior to cART initiation. We used the World Health Organization 2009 resistance mutation list and Stanford algorithm to infer resistance to prescribed drugs. Time to virological failure (VF) was defined as the first of two consecutive HIV-RNA > 500 copies/mL after 6 months cART and was assessed by Cox proportional hazards models. All models were adjusted for baseline demographic, clinical, immunology and virology characteristics and calendar period of cART start and initial cART regimen.

Results

Of 476 children, 88 % were vertically infected. At cART initiation, median (interquartile range) age was 6.6 years (2.1–10.1), CD4 cell count 297 cells/mm³ (98–639), and HIV-RNA 5.2 log₁₀copies/mL (4.7–5.7). Of 37 children (7.8 %, 95 % confidence interval (CI), 5.5–10.6) harboring a virus with ≥1 PDR mutations, 30 children had a virus resistant to ≥1 of the prescribed drugs. Overall, the cumulative Kaplan-Meier estimate for virological failure was 19.8 % (95 %CI, 16.4–23.9). Cumulative risk for VF tended to be higher among children harboring a virus with PDR and resistant to ≥1 drug prescribed than among those receiving fully active cART: 32.1 % (17.2–54.8) versus 19.4 % (15.9–23.6) (P = 0.095). In multivariable analysis, age was associated with a higher risk of VF with a 12 % reduced risk per additional year (HR 0.88; 95 %CI, 0.82–0.95; P < 0.001).

Conclusions

PDR was not significantly associated with a higher risk of VF in children in the first year of cART. The risk of VF decreased by 12 % per additional year at treatment initiation which may be due to fading of PDR mutations over time. Lack of appropriate formulations, in particular for the younger age group, may be an important determinant of virological failure.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1968-2) contains supplementary material, which is available to authorized users.

HIV Drug Resistance Among Children Initiating First-Line Antiretroviral Treatment in Uganda

Background: There are limited data on primary human immunodeficiency virus drug resistance (HIVDR) in pediatric populations. This study aimed to assess the prevalence of primary HIVDR and associated risk factors among children initiating first-line antiretroviral therapy (ART) in Uganda.

Methods: At three Ugandan clinics, children (age <12 years) requiring ART were recruited between January 2010 and August 2011. Before starting ART, blood was collected for viral load and pol gene sequencing. Drug resistance mutations were determined using the 2010 International AIDS Society–USA mutation list. Risk factors for HIVDR were assessed with multivariate regression analysis.

Results: Three hundred nineteen HIV-infected children with a median age of 4.9 years were enrolled. Sequencing was successful in 279 children (87.5%). HIVDR was present in 10% of all children and 15.2% of children <3 years. Nucleoside reverse transcriptase inhibitors (NRTIs), non-NRTI (NNRTI), and dual-class resistance was present in 5.7%, 7.5%, and 3.2%, respectively. HIVDR occurred in 35.7% of prevention of mother-to-child transmission (PMTCT)–exposed children, 15.6% in children with unknown PMTCT history, and 7.7% among antiretroviral-naive children. History of PMTCT exposure [adjusted odds ratio (AOR): 2.6, 95% CI: 1.3–5.1] or unknown PMTCT status (AOR: 3.8, 95% CI: 1.1–13.5), low CD4 (AOR: 2.2, 95% CI: 1.3–3.6), current breastfeeding (AOR: 7.4, 95% CI: 2.6–21), and current maternal ART use (AOR: 6.4, 95% CI: 3.4–11.9) emerged as risk factors for primary HIVDR in multivariate analysis.

Conclusion: Pretreatment HIVDR is high, especially in children with PMTCT exposure. Protease inhibitor (PI)–based regimens are advocated by the World Health Organization, but availability in children is limited. Children with (unknown) PMTCT exposure, low CD4 count, current breastfeeding, or maternal ART need to be prioritized to receive PI-based regimens.

Viral Suppression and Resistance in a Cohort of Perinatally-HIV Infected (PHIV+) Pregnant Women

Our objective was to describe viral suppression and antiretroviral (ARV) resistance mutations in an ongoing cohort of perinatally-infected HIV+ (PHIV+) pregnant women. Descriptive analysis was performed using SPSS 18.0. From 2011 to 2014, we followed 22 PHIV+ pregnant women. Median age at prenatal entry was 19 years (Interquartile range (IQR) 17.6–21.0); 86% had an AIDS diagnosis; 81% had disclosed their HIV status to partner 11. The median age at HIV diagnosis was 8.3 y (IQR 4.0–13.6), the median age at sexual debut was 16 years (IQR 14–18). At the time of prenatal care initiation, four (18%) were on their first antiretroviral treatment (ART), eight (36%) in their second regimen and nine (41%) in their third regimen or beyond, and one had no data. Seventeen of 22 (77%) had HIV-viral load (VL) > 50 copies/mL at prenatal care entry, 16 had a genotyping exam performed. Seventeen of 22 PHIV+ had VL results near delivery: 7/17 (41%) had VL < 50 copies/mL. Among those who had genotyping at prenatal entry, 11/16 (69%) had mutations associated with ARV resistance. The most frequent major mutations were K103N, M184V, T215, M41L, D67N at reverse transcriptase gene and M46, I54V and V82A at protease gene. No vertical transmissions occurred. Management of pregnancy among PHIV+ is challenging. Individualized ART are needed to achieve viral suppression in a highly ART-exposed subpopulation.

Factors associated with the failure of first and second-line antiretroviral therapies therapy, a case control study in Cambodian HIV-1 infected children

Background

Little is known about the efficacy of first and and second-line antiretroviral therapies (ART) for HIV-1 infected children in resource limited Southeast Asian settings. Previous studies have shown that orphans are at a higher risk for virological failure (VF) in Cambodia. Consequently most of them required transfer to second-line ART. We assessed the factors associated with VF among HIV-1 infected children who were either under first-line (mostly 3TC + D4T + NVP) or under second-line (mostly ABC + DDI + LPV) therapies at a referral hospital in Cambodia.

Methods

A case-control study was conducted from February to July 2013 at the National Pediatric Hospital among HIV-1 infected children (aged 1–15 years) under second-line ART (cases) or first-line (matched controls at a ratio of 1:3) regimens. Children were included if a HIV-1 RNA plasma viral load (VL) result was available for the preceding 12 months. A standardized questionnaire explored family sociodemographics, HIV history, and adherence to ART. Associations between VF (HIV-1 RNA levels ≥1000 copies/ml) and the children’s characteristics were assessed using bivariate and multivariate analyses.

Results

A total of 232 children, 175 (75.4 %) under first-line and 57 (24.6 %) under second-line ART, for a median of 72.0 (IQR: 68.0–76.0) months, were enrolled. Of them, 94 (40.5 %) were double orphans and 51 (22.0 %) single orphans, and 77 (33.2 %) were living in orphanages. A total of 222 children (95.6 %) were deemed adherent to ART. Overall, 18 (7.7 %; 95 % CI 4.6–11.9) showed a VF, 14 (8.6 %; 95 % CI 4.8–14.0) under first-line and 4 (7.0 %; 95 % CI 1.9–17.0) under second-line ART (p = 0.5). Their median CD4 percentage was 8 % (IQR 2.9–12.9) at ART initiation. Children under second-line ART were older; more often double orphans, and had lower CD4 cell counts at the last control.

In the multivariate analysis, having the last CD4 percentage below 15 % was the only factor associated with VF for ART regimen separately or when combined (OR 40.4; 95 % CI 11–134).

Conclusions

The pattern of risk factors for VF in children is changing in Cambodia. Improved adherence evaluation and intensified monitoring of children with low CD4 counts is needed to decrease the risk of VF.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-016-1884-y) contains supplementary material, which is available to authorized users.

The physical and psychological effects of HIV infection and its treatment on perinatally HIV-infected children

INTRODUCTION

As highly active antiretroviral therapy (HAART) transforms human immunodeficiency virus (HIV) into a manageable chronic disease, new challenges are emerging in treating children born with HIV, including a number of risks to their physical and psychological health due to HIV infection and its lifelong treatment.

METHODS

We conducted a literature review to evaluate the evidence on the physical and psychological effects of perinatal HIV (PHIV+) infection and its treatment in the era of HAART, including major chronic comorbidities.

RESULTS AND DISCUSSION

Perinatally infected children face concerning levels of treatment failure and drug resistance, which may hamper their long-term treatment and result in more significant comorbidities. Physical complications from PHIV+ infection and treatment potentially affect all major organ systems. Although treatment with antiretroviral (ARV) therapy has reduced incidence of severe neurocognitive diseases like HIV encephalopathy, perinatally infected children may experience less severe neurocognitive complications related to HIV disease and ARV neurotoxicity. Major metabolic complications include dyslipidaemia and insulin resistance, complications that are associated with both HIV infection and several ARV agents and may significantly affect cardiovascular disease risk with age. Bone abnormalities, particularly amongst children treated with tenofovir, are a concern for perinatally infected children who may be at higher risk for bone fractures and osteoporosis. In many studies, rates of anaemia are significantly higher for HIV-infected children. Renal failure is a significant complication and cause of death amongst perinatally infected children, while new data on sexual and reproductive health suggest that sexually transmitted infections and birth complications may be additional concerns for perinatally infected children in adolescence. Finally, perinatally infected children may face psychological challenges, including higher rates of mental health and behavioural disorders. Existing studies have significant methodological limitations, including small sample sizes, inappropriate control groups and heterogeneous definitions, to name a few.

CONCLUSIONS

Success in treating perinatally HIV-infected children and better understanding of the physical and psychological implications of lifelong HIV infection require that we address a new set of challenges for children. A better understanding of these challenges will guide care providers, researchers and policymakers towards more effective HIV care management for perinatally infected children and their transition to adulthood.

Long-Range HIV Genotyping Using Viral RNA and Proviral DNA for Analysis of HIV Drug Resistance and HIV Clustering

The goal of the study was to improve the methodology of HIV genotyping for analysis of HIV drug resistance and HIV clustering. Using the protocol of Gall et al. (A. Gall, B. Ferns, C. Morris, S. Watson, M. Cotten, M. Robinson, N. Berry, D. Pillay, and P. Kellam, J Clin Microbiol 50:3838-3844, 2012, doi:10.1128/JCM.01516-12), we developed a robust methodology for amplification of two large fragments of viral genome covering about 80% of the unique HIV-1 genome sequence. Importantly, this method can be applied to both viral RNA and proviral DNA amplification templates, allowing genotyping in HIV-infected subjects with suppressed viral loads (e.g., subjects on antiretroviral therapy [ART]). The two amplicons cover critical regions across the HIV-1 genome (including pol and env), allowing analysis of mutations associated with resistance to protease inhibitors, reverse transcriptase inhibitors (nucleoside reverse transcriptase inhibitors [NRTIs] and nonnucleoside reverse transcriptase inhibitors [NNRTIs]), integrase strand transfer inhibitors, and virus entry inhibitors. The two amplicons generated span 7,124 bp, providing substantial sequence length and numbers of informative sites for comprehensive phylogenic analysis and greater refinement of viral linkage analyses in HIV prevention studies. The long-range HIV genotyping from proviral DNA was successful in about 90% of 212 targeted blood specimens collected in a cohort where the majority of patients had suppressed viral loads, including 65% of patients with undetectable levels of HIV-1 RNA loads. The generated amplicons could be sequenced by different methods, such as population Sanger sequencing, single-genome sequencing, or next-generation ultradeep sequencing. The developed method is cost-effective-the cost of the long-range HIV genotyping is under $140 per subject (by Sanger sequencing)-and has the potential to enable the scale up of public health HIV prevention interventions.

Clinical and virologic follow-up in perinatally HIV-1-infected children and adolescents in Madrid with triple-class antiretroviral drug-resistant viruses

Drug resistance mutations compromise the success of antiretroviral treatment in human immunodeficiency virus type 1 (HIV-1)-infected children. We report the virologic and clinical follow-up of the Madrid cohort of perinatally HIV-infected children and adolescents after the selection of triple-class drug-resistant mutations (TC-DRM). We identified patients from the cohort carrying HIV-1 variants with TC-DRM to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors and protease inhibitors according to IAS-USA-2013. We recovered pol sequences or resistance profiles from 2000 to 2011 and clinical-immunologic-virologic data from the moment of TC-DRM detection until December 2013. Viruses harbouring TC-DRM were observed in 48 (9%) of the 534 children and adolescents from 2000 to 2011, rising to 24.4% among those 197 with resistance data. Among them, 95.8% were diagnosed before 2003, 91.7% were Spaniards, 89.6% carried HIV-1-subtype B and 75% received mono/dual therapy as first regimen. The most common TC-DRM present in ≥50% of them were D67NME, T215FVY, M41L and K103N (retrotranscriptase) and L90M (protease). The susceptibility to darunavir, tipranavir, etravirine and rilpivirine was 67.7%, 43.7%, 33.3% and 33.3%, respectively, and all reported high resistance to didanosine, abacavir and nelfinavir. Despite the presence of HIV-1 resistance mutations to the three main antiretroviral families in our paediatric cohort, some drugs maintained their susceptibility, mainly the new protease inhibitors (tipranavir and darunavir) and nonnucleoside reverse transcriptase inhibitors (etravirine and rilpivirine). These data will help to improve the clinical management of HIV-infected children with triple resistance in Spain.