HIV-1 drug resistance at antiretroviral treatment initiation in children previously exposed to single-dose nevirapine

Virulence and Replicative Fitness of HIV-1 Transmitted/Founder (T/F) Viruses Harbouring Drug Resistance-Associated Mutation

The biological characteristics of early transmitted/founder (T/F) variants are crucial factors for viral transmission and constitute key determinants for the development of better therapeutics and vaccine strategies. The present study aimed to generate T/F viruses and to characterize their biological properties. For this purpose, we constructed 18 full-length infectious molecular clones (IMCs) of HIV from recently infected infants. All the clones were characterized genotypically through whole genome sequencing and phenotypically for infectivity, replication kinetics, co-receptor usage, as well as their susceptibility to neutralizing antibodies and entry inhibitors using standard virological assays. Genotypic analysis revealed that all the T/F clones were of non-recombinant subtype C, but some of them harboured the Y181C drug resistance mutation associated with resistance to the non-nucleoside reverse transcriptase inhibitor (NNRTI) class of antiretroviral drugs. In vitro studies showed that while all the IMCs were capable of replicating in PBMCs and utilized the CCR5 co-receptor for cellular entry, the drug-resistant variants had significantly lower replicative capacity and per particle infectivity than the drug-sensitive viruses. Both exhibited similar sensitivities to a standard panel of broadly neutralizing monoclonal antibodies and viral entry inhibitors. These findings suggest that despite their diminished replicative fitness, the drug-resistant T/F variants retain transmission fitness and remain susceptible to neutralizing antibody-based interventions and viral entry inhibitors.

Global, regional, and national prevalence of HIV-1 drug resistance in treatment-naive and treatment-experienced children and adolescents: a systematic review and meta-analysis

Background

Despite significant reductions in mother-to-child HIV-1 transmission risks due to the advancements and scale-up of antiretroviral therapy (ART), the global burden of HIV-1 drug resistance (HIVDR) in treatment-naive and treatment-experienced children and adolescents remains poorly understood. In this study, we conducted a systematic review and meta-analysis to estimate the prevalence of HIVDR in these populations globally, regionally, and at the country level.

Methods

We systematically searched PubMed, Embase, and Web of Science for studies reporting HIVDR in treatment-naive and treatment-experienced children and adolescents from inception to June 28, 2024. Eligible studies reported at least ten successfully genotyped cases. We excluded studies where drug resistance was not reported separately for children and adults or for treatment-naive and treatment-experienced populations. The methodological quality of eligible studies was assessed, and random-effect models were used for meta-analysis to determine the pooled overall and regimen-specific prevalence of one or more HIVDR mutations in these populations globally, regionally, or at the country level. This study is registered with PROSPERO under the number CRD42023424483.

Findings

Of 2282 records identified, 136 studies (28,539 HIV-1-infected children from 52 countries) were included for analysis. The overall prevalence of HIVDR is 26.31% (95% CI, 20.76-32.25) among treatment-naive children and 74.16% (95% CI, 67.74-80.13) among treatment-experienced children (p < 0.0001). HIVDR varied widely across subregion with the highest prevalence in Southern Africa (37.80% [95% CI, 26.24-50.08]) and lowest in South America (11.79% [95% CI, 4.91-20.84]) for treatment-naive children while highest in Asia (80.85% [95% CI, 63.76-93.55]) and lowest in Europe (54.39% [95% CI, 28.61-79.03]) for treatment-experienced children. The proportion of viral failure (VF) presented positive correlation with DR prevalence for treatment-experienced children, which increased from 61.23% (95% CI, 47.98-73.72) in proportion of VF <50%-81.17% (95% CI, 71.57-89.28) in proportion of 100%. Meta-regression analysis for both groups showed that only age (naive: p = 0.0005; treated: p < 0.0001) was the sources of heterogeneity. Non-nucleoside reverse transcriptase inhibitor (NNRTI) resistances were the most seen mutations among the treatment-naive group, with the HIVDR prevalence more than 10% in Southern Africa, Western and Central Africa, Eastern Africa, Asia, and North America. Both nucleoside reverse transcriptase inhibitor (NRTI) and NNRTI resistances were commonly seen among the treatment-experienced group, varying from 36.33% (95% CI, 11.96-64.93) in North America to 77.54% (95% CI, 62.70-89.58) in South America for NRTI and from 39.98% (95% CI, 13.47-69.97) in Europe to 68.86 (95% CI, 43.91-89.17) in Asia for NNRTI, respectively.

Interpretation

This study underscores the significant burden of HIVDR among children and adolescents worldwide, particularly pronounced in sub-Saharan Africa and low-income countries. It emphasizes the critical importance of surveillance in all HIV-1-infected children and advocates for the adoption of dolutegravir (DTG) or other optimal formulations as first-line ART in settings where NNRTI resistance exceeds the WHO's 10% threshold. DTG's high resistance barrier, potent antiviral efficacy, and favorable safety profile makes it a superior choice for managing drug-resistant HIV-1, surpassing traditional antiretroviral therapies.

Funding

This work was supported by the Science and Technology Innovation Committee of Shenzhen Municipality (No. JCYJ20220531102202005) and the Natural Science Foundation of Guangdong Province (No. 2024A1515012118).

The association between HIV pretreatment drug resistance and virological outcomes in children and adults in sub-Saharan Africa: A systematic review and meta-analysis

INTRODUCTION

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

METHODS

This report is presented following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The method was subdivided into three main phases: record identification, screening, and report inclusion. Record identification consisted of an initial search with search term "HIV pretreatment drug resistance". Another search was done using terms "Pretreatment drug resistance OR pre-treatment drug resistance OR Pretreatment drug resist* OR pre-treatment drug resist* OR pretreatment antiretroviral resistance OR pretreatment medic* OR pretreatment medic* resist*" and a list of all the countries in sub-Saharan Africa. After the electronic search, studies were screened from full list based on their title and abstract and then full articles retrieved and studies were assessed based on set criteria. Inclusion criteria involved observational studies that report the association between PDR and virological failure. Data from trials that reported the association were also included. Published articles like modelling studies and reviews, and studies with data that had been previously included in the review were excluded. The Mantel Haenszel method with odds ratios was used for synthesis (meta-analyses) with the weights of each study which depends on the number of events and totals.

RESULTS

A total of 733 records(studies) were obtained from all database search of which 74 reported on PDR, virological outcomes in sub-Saharan Africa (SSA). Out of the 74 articles, 11 were excluded and 26 did not explicitly report data needed, and 5 did not meet the inclusion criteria. Of the remaining 32 studies, 19 studies that had complete data on the number of participants with PDR and no PDR according to virological failure (VF) were included in the metanalyses. The pooled results from eleven (13) of these studies showed those with PDR had higher odds of virological failure compared to those without PDR OR 3.64[95% CI 2.93, 4.52]. The result was similar when stratified in adults and in children. In six (6) studies that had Virological suppression (VS) as outcome, there was a reduction in the odds of VS in those with PDR compared to those without PDR, OR 0.42 (95% CI 0.30, 0.58).

CONCLUSION

In conclusion, this systematic review indicates that PDR increases the risk of virological failure in sub-Saharan Africa. The risk could be reduced by PDR monitoring for NNRTIs and INSTIs.

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.

Maternal HIV drug resistance is associated with vertical transmission and is prevalent in infected infants

BACKGROUND

We aimed to assess if maternal HIV drug resistance is associated with an increased risk of HIV vertical transmission and to describe the dynamics of drug resistance in HIV-infected infants.

METHODS

A case-control study of PROMISE study participants. "Cases" were mother-infant pairs with HIV vertical transmission during pregnancy or breastfeeding and "controls" were mother-infant pairs without transmission matched 1:3 by delivery date and clinical site. Genotypic HIV drug resistance analyses were performed on mothers' and their infants' plasma at or near the time of infant HIV diagnosis. Longitudinal analysis of genotypic resistance was assessed in available specimens from infants, from diagnosis and beyond, including ART initiation and last study visits.

RESULTS

Our analyses included 85 cases and 255 matched controls. Maternal HIV drug resistance, adjusted for plasma HIV RNA load at infant HIV diagnosis, enrollment CD4 count, and antepartum regimens, was not associated with in utero/peripartum HIV transmission. In contrast, both maternal plasma HIV RNA load and HIV drug resistance were independent risk factors associated with vertical transmission during breastfeeding. Furthermore, HIV drug resistance was selected across infected infants during infancy.

CONCLUSIONS

Maternal HIV drug resistance and maternal viral load were independent risk factors for vertical transmission during breastfeeding, suggesting that nevirapine alone may be insufficient infant prophylaxis against drug-resistant variants in maternal breast milk. These findings support efforts to achieve suppression of HIV replication during pregnancy and suggest that breastfeeding infants may benefit from prophylaxis with a greater barrier to drug resistance than nevirapine alone.

Survey of Pretreatment HIV Drug Resistance and Genetic Transmission Network Analysis Among HIV Patients in a High Drug-Use Area of Southwest China

Background: Pretreatment drug resistance (PDR) poses an increasing threat to the success of antiretroviral treatment (ART) programs in China. We aimed to conduct a survey of PDR among HIV patients in an area in Southwest China with extensive drug trafficking.

Methods: Consecutive cross-sectional surveys were conducted in Liangshan Prefecture of Sichuan Province from 2009 to 2018 based on the WHO-recommended method. PDR was identified by testing pol region sequences with the Stanford HIVdb algorithm (version 7.0). PDR prevalence and related factors were assessed by multivariable logistic regression. The transmission of HIV drug resistance was analyzed using a genetic transmission network.

Results: HIV-1 pol genes from 1889 patients were successfully amplified. The distribution of HIV-1 genotypes was as follows: CRF07_BC (94.0%), CRF08_BC (2.3%), CRF01_AE (2.0%) and others (1.4%). Of the participants, 6.9% (95% CI: 4.1-8.1%) had pretreatment resistance to 12 antiretroviral drugs recommended by the WHO, and nucleoside reverse transcriptase inhibitor (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitors (PI) resistance were identified among 1.4% (95% CI: 0.7-3.4%), 5.8% (95% CI: 1.2-8.7%) and 0.4% (95% CI: 0.1-3.0%) of the patients, respectively. In the multivariate logistic model, the prevalence of PDR was 1.52-fold higher among intravenous drug users (IDUs) than among patients infected by heterosexual transmission (95% CI: 1.07-2.38; P=0.049), and the prevalence of PDR among patients diagnosed from 2017-2018 was 2.03-fold higher than that among patients diagnosed from 2009-2016 (95% CI: 1.18-5.76; P=0.018). A total of 26 clusters containing PDR and a rapidly growing drug resistance-related cluster containing the E138Q and V179D mutations were identified by genetic transmission network analysis.

Conclusion: The results show a moderate overall level of PDR prevalence and rapidly growing drug resistance over time. Preventive intervention should be focused on controlling the HIV epidemic among drug users, and surveillance is urgently needed to monitor the trend of PDR.

Potential challenges to sustained viral load suppression in the HIV treatment programme in South Africa: a narrative overview

Background

South Africa, with one of the highest HIV prevalences in the world, introduced the universal test and treat (UTT) programme in September 2016. Barriers to sustained viral suppression may include drug resistance in the pre-treated population, non-adherence, acquired resistance; pharmacokinetics and pharmacodynamics, and concurrent use of alternative treatments.

Objective

The purpose of this review is to highlight potential challenges to achieving sustained viral load suppression in South Africa (SA), a major expectation of the UTT initiative.

Methodology

Through the PRISMA approach, published articles from South Africa on transmitted drug resistance; adherence to ARV; host genetic factors in drug pharmacokinetics and pharmacodynamics, and interactions between ARV and herbal medicine were searched and reviewed.

Results

The level of drug resistance in the pre-treated population in South Africa has increased over the years, although it is heterogeneous across and within Provinces. At least one study has documented a pre-treated population with moderate (> 5%) or high (> 15%) levels of drug resistance in eight of the nine Provinces. The concurrent use of ARV and medicinal herbal preparation is fairly common in SA, and may be impacting negatively on adherence to ARV. Only few studies have investigated the association between the genetically diverse South African population and pharmacokinetics and pharmacodynamics of ARVs.

Conclusion

The increasing levels of drug resistant viruses in the pre-treated population poses a threat to viral load suppression and the sustainability of first line regimens. Drug resistance surveillance systems to track the emergence of resistant viruses, study the burden of prior exposure to ARV and the parallel use of alternative medicines, with the goal of minimizing resistance development and virologic failure are proposed for all the Provinces of South Africa. Optimal management of the different drivers of drug resistance in the pre-treated population, non-adherence, and acquired drug resistance will be beneficial in ensuring sustained viral suppression in at least 90% of those on treatment, a key component of the 90-90-90 strategy.

Compromise of Second-Line Antiretroviral Therapy Due to High Rates of Human Immunodeficiency Virus Drug Resistance in Mozambican Treatment-Experienced Children With Virologic Failure

BACKGROUND

Virologic failure (VF) is highly prevalent in sub-Saharan African children on antiretroviral therapy (ART) and is often associated with human immunodeficiency virus drug resistance (DR). Most children still lack access to routine viral load (VL) monitoring for early identification of treatment failure, with implications for the efficacy of second-line ART.

METHODS

Children aged 1 to 14 years on ART for ≥12 months at 6 public facilities in Maputo, Mozambique were consecutively enrolled after informed consent. Chart review and caregiver interviews were conducted. VL testing was performed, and specimens with ≥1000 copies/mL were genotyped.

RESULTS

Of the 715 children included, the mean age was 103 months, 85.8% had no immunosuppression, 73.1% were taking stavudine/lamivudine/nevirapine, and 20.1% had a history prevention of mother-to-child transmission exposure. The mean time on ART was 60.0 months. VF was present in 259 patients (36.3%); 248 (95.8%) specimens were genotyped, and DR mutations were found in 238 (96.0%). Severe immunosuppression and nutritional decline were associated with DR. M184V and Y181C were the most common mutations. In the 238 patients with DR, standard second-line ART would have 0, 1, 2, and 3 effective antiretrovirals in 1 (0.4%), 74 (31.1%), 150 (63.0%), and 13 (5.5%) patients, respectively.

CONCLUSION

This cohort had high rates of VF and DR with frequent compromise of second-line ART. There is urgent need to scale-up VL monitoring and heat-stable protease inhibitor formulations or integrase inhibitorsfor a more a durable first-line regimen that can feasibly be implemented in developing settings.

Prevalence of HIV-1 drug resistance amongst newly diagnosed HIV-infected infants age 4-8 weeks, enrolled in three nationally representative PMTCT effectiveness surveys, South Africa: 2010, 2011-12 and 2012-13

BACKGROUND

South Africa (SA) has expanded efforts to reduce mother-to-child transmission of HIV (MTCT) to less than 2% at six weeks after birth and to less than 5% at 18 months postpartum by 2016. Despite improved antiretroviral regimens and coverage between 2001 and 2016, there is little data on infant HIV drug resistance. This paper tracks the prevalence of HIV drug resistance patterns amongst HIV infected infants from three nationally representative studies that assessed the effectiveness of national programs to prevent MTCT (PMTCT). The first study was conducted in 2010 (under the dual therapy PMTCT policy), the second from 2011 to 12 (PMTCT Option A policy) and the third from 2012 to 13 (PMTCT Option A policy). From 2010 to 2013, infant non-nucleoside reverse transcriptase inhibitor (NNRTI) exposure increased from single dose to daily throughout breastfeeding; maternal nucleoside reverse transcriptase inhibitor (NRTI) and NNRTI exposure increased with initiation of NNRTI-and NRTI- containing triple antiretroviral therapy (ART) earlier in gestation and at higher CD4 cell counts.

METHODS

Three nationally representative surveys were conducted in 2010, 2011-12 and 2012-13. During the surveys, mothers with known, unknown, or no exposure to antiretrovirals for PMTCT and their infants were included, and MTCT was measured. For this paper, infant dried blood spots (iDBS) from HIV PCR positive infants aged 4-8 weeks, with consent for additional iDBS testing, were analysed for HIV drug resistance at the National Institute of Communicable Diseases (NICD), SA, using an in-house assay validated by the Centers for Disease Control and Prevention (CDC). Total viral nucleic acid was extracted from 2 spots and amplified by nested PCR to generate a ~ 1 kb amplicon that was sequenced using Sanger sequencing technologies. Sequence assembly and editing was performed using RECall v3.

RESULTS

Overall, HIV-1 drug resistance was detected in 51% (95% Confidence interval (CI) [45-58%]) of HIV PCR positive infants, 37% (95% CI [28-47%]) in 2010, 64% (95% CI [53-74%]) in 2011 and 63% (95% CI [47-77%]) in 2012 (p < 0.0001), particularly to the NNRTI drug class. Pooled analyses across all three surveys demonstrated that infants whose mothers received ART showed the highest prevalence of resistance (74%); 26% (21/82) of HIV PCR positive infants with no or undocumented antiretroviral drug (ARV) exposure harboured NNRTI resistance.

CONCLUSIONS

These data demonstrate increasing NNRTI resistance amongst newly-diagnosed infants in a high HIV prevalence setting where maternal ART coverage increased across the years, starting earlier in gestation and at higher CD4 cell counts. This is worrying as lifelong maternal ART coverage for HIV positive pregnant and lactating women is increasing. Also of concern is that resistant virus was detected in HIV positive infants whose mothers were not exposed to ARVs, raising questions about circulating resistant virus. Numbers in this group were too small to assess trends over the three years.

Switching to Efavirenz Versus Remaining on Ritonavir-boosted Lopinavir in Human Immunodeficiency Virus-infected Children Exposed to Nevirapine: Long-term Outcomes of a Randomized Trial

Background

We previously demonstrated the noninferiority of switching to efavirenz (EFV) versus remaining on ritonavir-boosted lopinavir (LPV/r) for virologic control in children infected with human immunodeficiency virus (HIV) and exposed to nevirapine (NVP) for prevention of mother-to-child transmission. Here we assess outcomes up to 4 years post-randomization.

Methods

From 2010-2013, 298 NVP-exposed HIV-infected children ≥3 years of age were randomized to switch to EFV or remain on LPV/r in Johannesburg, South Africa (Clinicaltrials.gov NCT01146873). After trial completion, participants were invited to enroll into observational follow-up. We compared HIV RNA levels, CD4 counts and percentages, lipids, and growth across groups through four years post-randomization.

Results

HIV RNA levels 51-1000 copies/mL were less frequently observed in the EFV group than the LPV/r group (odds ratio [OR] 0.67, 95% confidence interval [CI]: 0.51-0.88, P = .004), as was HIV RNA >1000 copies/mL (OR 0.52 95% CI: 0.28-0.98, P = .04). The probability of confirmed HIV RNA >1000 copies/mL by 48 months was 0.07 and 0.12 in the EFV and LPV/r groups, respectively (P = .21). Children randomized to EFV had a reduced risk of elevated total cholesterol (OR 0.45 95% CI: 0.27-0.75, P = .002) and a reduced risk of abnormal triglycerides (OR 0.42, 95% CI 0.29-0.62, P < .001).

Conclusions

Our results indicate that the benefits of switching virologically suppressed NVP-exposed HIV-infected children ≥3 years of age from LPV/r to EFV are sustained long-term. This approach has several advantages, including improved palatability, reduced metabolic toxicity, simplified cotreatment for tuberculosis, and preservation of second line options.

Clinical Trials Registration

NCT01146873.

The pharmacological treatment of acute HIV infections in neonates

INTRODUCTION

Recent goals of antiretroviral treatment of neonates have expanded from reducing morbidity and mortality to also aiming to facilitate HIV remission. Areas covered: In this review, we present and discuss the rationale and evidence-bases for each of these distinct goals. Next we discuss the challenges of how to identify HIV-infected neonates. Finally, we discuss the specific antiretroviral drugs that are preferred for this group, making distinctions between the use of these agents in prevention and treatment. Expert commentary: The clinical and scientific challenges of pharmacological treatment of acute HIV infection in neonates are complicated by externalities beyond biology. At the same time, these challenges are energized by the unique biological opportunities afforded by investigating this population, including a unique immune profile, ability to study both mother and neonate as well as transmitted and acquired virus, and time period spanning both the period soon after infection as well as the period of viral reservoir establishment and related damage. Given the unique scientific opportunities afforded by study of pharmacologic treatment of acute HIV infection in neonates, we hypothesize that over the next five years breakthroughs may occur that may lead to new interventions effective at achieving HIV remission.

High Rates of Baseline Drug Resistance and Virologic Failure Among ART-naive HIV-infected Children in Mali

BACKGROUND

Limited data exist on drug resistance and antiretroviral treatment (ART) outcomes in HIV-1-infected children in West Africa. We determined the prevalence of baseline resistance and correlates of virologic failure (VF) in a cohort of ART-naive HIV-1-infected children <10 years of age initiating ART in Mali.

METHODS

Reverse transcriptase and protease genes were sequenced at baseline (before ART) and at 6 months. Resistance was defined according to the Stanford HIV Genotypic Resistance database. VF was defined as viral load ≥1000 copies/mL after 6 months of ART. Logistic regression was used to evaluate factors associated with VF or death >1 month after enrollment. Post hoc, antiretroviral concentrations were assayed on baseline samples of participants with baseline resistance.

RESULTS

One-hundred twenty children with a median age 2.6 years (interquartile range: 1.6-5.0) were included. Eighty-eight percent reported no prevention of mother-to-child transmission exposure. At baseline, 27 (23%), 4 (3%) and none had non-nucleoside reverse transcriptase inhibitor (NNRTI), nucleoside reverse transcriptase inhibitor or protease inhibitor resistance, respectively. Thirty-nine (33%) developed VF and 4 died >1 month post-ART initiation. In multivariable analyses, poor adherence [odds ratio (OR): 6.1, P = 0.001], baseline NNRTI resistance among children receiving NNRTI-based ART (OR: 22.9, P < 0.001) and protease inhibitor-based ART initiation among children without baseline NNRTI resistance (OR: 5.8, P = 0.018) were significantly associated with VF/death. Ten (38%) with baseline resistance had detectable levels of nevirapine or efavirenz at baseline; 7 were currently breastfeeding, but only 2 reported maternal antiretroviral use.

CONCLUSIONS

Baseline NNRTI resistance was common in children without reported NNRTI exposure and was associated with increased risk of treatment failure. Detectable NNRTI concentrations were present despite few reports of maternal/infant antiretroviral use.

Persistence of HIV drug resistance among South African children given nevirapine to prevent mother-to-child-transmission

OBJECTIVES

We set out to examine the prevalence and persistence of mutations conferring high-level nonnucleoside reverse transcriptase (NNRTI)-resistance in a cohort of HIV-infected children who had failed prophylaxis to prevent mother-to-child-transmission (PMTCT).

DESIGN

A prospective observational cohort study at the Pediatric HIV Clinic at Kalafong Provincial Tertiary Hospital in Pretoria, South Africa.

METHODS

Children referred for initiation of antiretroviral therapy (ART) were enrolled from July 2010 through February 2013. HIV drug resistance testing was performed using the oligonucleotide ligation assay (OLA) on dried blood spots (DBS) collected at enrolment and monthly follow-up visits for 2 years.

RESULTS

South African children who failed HIV-prophylaxis had a high prevalence of NNRTI-resistant HIV (46/88; 52%). Among children with NNRTI-resistance, the frequency of the predominant resistant variant in each child's HIV-quasispecies was high (median 96%) at study entry (median age 7.5 months), and in 26 out of 27 followed a median of 13 months persisted at a high frequency (median 89%).

CONCLUSION

Our finding that infants who fail HIV-prophylaxis frequently have long-lived NNRTI-resistant HIV suggests that resistance will likely persist through 36 months of age, when children qualify for NNRTI-based ART. These children may benefit from HIV drug resistance testing to guide selection of their treatment.

Rapid Detection of Common HIV-1 Drug Resistance Mutations by Use of High-Resolution Melting Analysis and Unlabeled Probes

HIV rapidly accumulates resistance mutations following exposure to subtherapeutic concentrations of antiretroviral drugs that reduces treatment efficacy. High-resolution melting analysis (HRMA) has been used to successfully identify single nucleotide polymorphisms (SNPs) and to genotype viral and bacterial species. Here, we tested the ability of HRMA incorporating short unlabeled probes to accurately assign drug susceptibilities at the 103, 181, and 184 codons of the HIV-1 reverse transcriptase gene. The analytical sensitivities of the HRMA assays were 5% of mixed species for K103N and Y181C and 20% for M184V. When applied to 153 HIV-1 patient specimens previously genotyped by Sanger population sequencing, HRMA correctly assigned drug sensitivity or resistance profiles to 80% of the samples at codon 103 (K103K/N) (Cohen's kappa coefficient [κ] > 0.6; P < 0.05), 90% at 181 (Y181Y/C) (κ > 0.74, P < 0.05), and 80% at 184 (M184M/V) (κ > 0.62; P < 0.05). The frequency of incorrect genotypes was very low (≤1 to 2%) for each assay, which in most cases was due to the higher sensitivity of the HRMA assay. Specimens for which drug resistance profiles could not be assigned (9 to 20%) often had polymorphisms in probe binding regions. Thus, HRMA is a rapid, inexpensive, and sensitive method for the determination of drug sensitivities caused by major HIV-1 drug resistance mutations and, after further development to minimize the melting effects of nontargeted polymorphisms, may be suitable for surveillance purposes.

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.

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.

Pre-treatment drug resistance among patients initiating antiretroviral therapy (ART) in Zimbabwe: 2008-2010

Background

Zimbabwe set up 12 sentinel sites to monitor HIV drug resistance (HIVDR) following the international standards for prevention of HIVDR from 2008 to 2010.

Methods

Participants were consecutively enrolled. Blood was collected and used for CD4 count, viral load (VL) and pre-treatment DR (PDR) tests besides routine baseline tests. We analyzed the characteristics of participants enrolled into the survey and estimated the point prevalence of PDR and its associated factors among ART initiators in a cross-sectional analysis using the baseline data collected from a prospective cohort in 12 purposefully selected sentinel sites.

Results

A total of 1728 participants (96 % response rate) were enrolled and 1610 had complete data. Of the 1610 there were more females (68.7 %) than males (31.3 %). The median CD4 count was 168 cells/mm³ with males having lower values (P = 0.003). Ninety-six percent of participants had a VL ≥ 1000 copies/ml and the median VL was 128,000. Previous exposure to antiretroviral drugs (ARVs) was mainly through PMTCT (5 % of the participants). Overall, PDR mutations were detected in 6.3 % (95 % CI 5.2–7.7) of the 1480 successfully genotyped participants. However, the prevalence of PDR mutations was double for those with previous exposure (12.1 %) to ARVs compared with those without previous exposure (5.7 %, P = 0.002).

Conclusions

The results show a moderate level of PDR prevalence among ART initiators. To maintain the efficacy of the current first-line regimens, there is need to strengthen all HIVDR prevention efforts and to conduct further studies to investigate optimal strategies that can prolong the efficacy of first-line ARV regimens in the country.

The use of dried blood spot specimens for HIV-1 drug resistance genotyping in young children initiating antiretroviral therapy

Paired plasma and dried blood spots (DBS) from 232 South African HIV-infected children initiating antiretroviral therapy (ART) were genotyped for drug resistance mutations, most of who had prior exposure to ART for prevention-of-mother-to-child-transmission. Non-nucleoside reverse transcriptase inhibitor mutations were most commonly detected in both specimen types, particularly Y181C/I and K103N/S. Resistance interpretation concordance was achieved in 97% of pairs with seven children having mutations detected in DBS only. These results validate the preferential use of DBS specimens for HIVDR genotyping in this patient group.

Development of Nevirapine Resistance in Children Exposed to the Prevention of Mother-to-Child HIV-1 Transmission Programme in Maputo, Mozambique

BACKGROUND

Single-dose nevirapine (sd-NVP) has been the main option for prevention of mother-to-child transmission (PMTCT) of HIV-1 in low-resource settings. However, sd-NVP can induce the selection of HIV-1 resistant mutations in mothers and infants. In Mozambique, there are limited data regarding the profile of NVP resistance associated mutations (RAM) in the context of PMTCT.

OBJECTIVES

To assess the prevalence and the factors associated with NVP RAM among children born to HIV-1 infected mothers enrolled in the PMTCT programme adopted in Mozambique.

METHODS

One hundred and fifty seven children aged 6 to 48 weeks were sequentially included (July 2011 to March 2012) at four centres in Maputo. Genotyping of RAM was performed in samples with HIV-1 RNA≥ 100 copies/μL (Viroseq). Sequencing was performed with ABI 3100 (Applied Biosystems). Logistic regression modelling was undertaken to identify the factors associated with NVP RAM.

RESULTS

Seventy-nine children had their samples genotyped. Their median age was 7.0 (3-12) months and 92.4% received prophylaxis with sd-NVP at birth plus daily NVP. 35.4% of mothers received antiretrovirals (ARVs) for PMTCT. ARV RAM were detected in 43 (54.4%) of the children. 45.6% of these children had at least one NVP RAM. The most common mutations associated with NVP resistance were K103N (n = 16) and Y181C (n = 15). NVP RAM was significantly associated with mother exposure to PMTCT (crude odds ratio [OR] 30.3, 95% CI 4.93-186.34) and with mother's CD4 count < 350 cells/mm3 (crude OR 3.08, 95% CI 1.02-9.32). In the multivariable analysis the mother's exposure to PMTCT was the only variable significantly associated with NVP RAM (adjusted OR 48.65, 95% CI 9.33-253.66).

CONCLUSIONS

We found a high prevalence of NVP RAM among children who were exposed to the drug regimen for PMTCT in Mozambique. The mothers' exposure to PMTCT significantly increased the risk of NVP RAM.

A post-partum single-dose TDF/FTC tail does not prevent the selection of NNRTI resistance in women receiving pre-partum ZDV and intrapartum single-dose nevirapine to prevent mother-to- child HIV-1 transmission

Although the rates of vertical transmission of HIV in the developing world have improved to around 3% in countries like South Africa, resistance to antiretrovirals (ARV) used in Prevention of Mother‐to‐Child transmission (pMTCT) strategies may thwart such outcomes and affect the efficacy of future ARV regimens in mothers and children. This study conducted in Durban, South Africa, between 2010 and 2013 found a high rate of nevirapine (NVP) resistance among women receiving Zidovudine (AZT) from 14 weeks gestation, single dose nevirapine (sd NVP) at the onset of labor and a single dose of coformulated Tenofovir/Emtricitabine (TDF/FTC) postpartum. Using Sanger sequencing, high and intermediate levels of nevirapine (NVP) resistance were detected in 15/44 (34%) and in 1/44 (2%) of women tested, respectively. Most subjects selected the K103N mutation (22% (10/45) of all patients and 66% (10/15) of those with high‐level NVP resistance). Such rate of NVP resistance is comparable to studies where only sd NVP was used. In conclusion, a post‐partum single‐dose TDF/FTC tail does not prevent the selection of NNRTI resistance in women receiving pre‐partum ZDV and intrapartum sd NVP to prevent mother‐to‐child HIV‐1 transmission. J. Med. Virol. 87:1662–1667, 2015. © 2015 The Authors. Journal of Medical Virology published by Wiley Periodicals, Inc.

Drug resistance among newly diagnosed HIV-infected children in the era of more efficacious antiretroviral prophylaxis

BACKGROUND

In the era of more efficacious prevention of mother-to-child transmission (PMTCT) regimens, documenting the profile of drug resistance in HIV-infected infants and young children is critical to our efforts to improve care and treatment for children.

METHODS

HIV drug resistance mutations in plasma virus were ascertained using population sequencing among 230 newly diagnosed HIV-infected children under 2 years of age recruited in Johannesburg, South Africa, during 2011. By this time, more effective PMTCT regimens, including combination antiretroviral therapy for pregnant women, were being implemented.

RESULTS

Two-thirds (67.4%) of HIV-infected children had been exposed to some form of maternal (89%) and/or infant (97%) PMTCT. Among PMTCT-exposed, 56.8% had nonnucleoside reverse transcriptase inhibitor (NNRTI), 14.8% nucleoside reverse transcriptase inhibitor (NRTI), and 1.3% protease inhibitor mutations. NNRTI mutations were strongly related to younger age. The remaining third (32.6%) had no reported or recorded PMTCT exposures, but resistance to NNRTI was detected in 24.0%, NRTI in 10.7%, and protease inhibitor in 1.3%.

CONCLUSION

The new PMTCT strategies dramatically reduce the number of children who acquire infection, but among those who do become infected, NNRTI resistance prevalence is high. In this South African setting with high PMTCT coverage, almost a quarter of children with no reported or recorded PMTCT also have drug resistance mutations. PMTCT history is an inadequate means of ruling out pretreatment drug resistance. Our results support the use of protease inhibitor-based first-line regimens in HIV-infected infants and young children regardless of PMTCT history.

Concordance between allele-specific PCR and ultra-deep pyrosequencing for the detection of HIV-1 non-nucleoside reverse transcriptase inhibitor resistance mutations

Recent advances in genotyping technologies have allowed for detection of HIV-1 drug resistance mutations present at low levels. The presence and percentage of Y181C and K103N drug-resistant variants in the blood of 105 subtype C HIV-infected infants who failed single-dose nevirapine prophylaxis for HIV transmission were compared using two highly sensitive genotyping methods, allele-specific PCR (AS-PCR) and ultra-deep pyrosequencing. Significant correlations in detection between both methods were found for both Y181C (correlation coefficients of 0.94 [95% CI 0.91-0.96]) and K103N (0.89 [95% CI 0.84-0.92]) mutations. The majority of discordant specimens (3/5 Y181C and 8/11 K103N) had wild-type variants when population sequencing was used, but mutant variants were detectable at very low levels (≤5%) with either assay. This difference is most likely due to stochastic variations in the appearance of mutant variants. Overall, both AS-PCR and ultra-deep pyrosequencing methods have proven to be sensitive and accurate, and may confidently be used where feasible.

Optimisation of antiretroviral therapy in HIV-infected children under 3 years of age

BACKGROUND

In the absence of antiretroviral therapy (ART), over 50% of HIV-infected infants progress to AIDS and death by 2 years of age. However, there are challenges to initiation of ART in early life, including the possibility of drug resistance in the context of prevention of mother-to-child transmission (PMTCT) programs, a paucity of drug choices , uncertain dosing for some medications and long-term toxicities. Key management decisions include when to start ART, what regimen to start, and whether and when to substitute drugs or interrupt therapy. This review, an update of a previous review, aims to summarize the currently available evidence on this topic and inform the ART management in HIV-infected children less than 3 years of age.

OBJECTIVES

To evaluate 1) when to start ART in young children (less than 3 years); 2) what ART to start with, comparing first-line non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitor (PI)-based regimens; and 3) whether alternative strategies should be used to optimize antiretroviral treatment in this population: induction (initiation with 4 drugs rather than 3 drugs) followed by maintenance ART, interruption of ART and substitution of PI with NNRTI drugs once virological suppression is achieved on a PI-based regimen.

SEARCH METHODS

Search methodsWe searched for published studies in the Cochrane HIV/AIDS Review Group Trials Register, The Cochrane Library, Pubmed, EMBASE and CENTRAL. We screened abstracts from relevant conference proceedings and searched for unpublished and ongoing trials in clinical trial registries (ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform).

SELECTION CRITERIA

We identified RCTs that recruited perinatally HIV-infected children under 3 years of age without restriction of setting. We rejected trials that did not include children less than 3 years of age, did not provide stratified outcomes for those less than 3 years or did not evaluate either timing of ART initiation, choice of drug regimen or treatment switch/interruption strategy.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied study selection criteria, assessed study quality and extracted data. Effects were assessed using the hazard ratio (HR) for time-to-event outcomes, relative risk for dichotomous outcomes and weighted mean difference for continuous outcomes.

MAIN RESULTS

A search of the databases identified a total of 735 unique, previously unreviewed studies, of which 731 were excluded to leave 4 new studies to incorporate into the review. Four additional studies were identified in conference proceedings, for a total of 8 studies addressing when to start treatment (n=2), what to start (n=3), whether to substitute lopinavir/ritonavir (LPV/r) with nevirapine (NVP) (n=1), whether to use an induction-maintenance ART strategy (n=1) and whether to interrupt treatment (n=1).Treatment initiation in asymptomatic infants with good immunological status was associated with a 75% reduction (HR=0.25; 95%CI 0.12-0.51; p=0.0002) in mortality or disease progression in the one trial with sufficient power to address this question. In a smaller pilot trial, median CD4 cell count was not significantly different between early and deferred treatment groups 12 months after ART.Regardless of previous exposure to nevirapine for PMTCT, the hazard for treatment failure at 24 weeks was 1.79 (95%CI 1.33, 2.41) times higher in children starting ART with a NVP-based regimen compared to those starting with a LPV/r-based regimen (p=0.0001) with no clear difference in the effect observed for children younger or older than 1 year. The hazard for virological failure at 24 weeks was overall 1.84 (95%CI 1.29, 2.63) times higher for children starting ART with a NVP-based regimen compared to those starting with a LPV/r-based regimen (p=0.0008) with a larger difference in time to virological failure (or death) between the NVP and LPV/r-based regimens when ART was initiated in the first year of life.Infants starting a LPV/r regimen and achieving sustained virological suppression who then substituted LPV/r with NVP after median 9 months on LPV/r were less likely to develop virological failure (defined as at least one VL greater than 50 copies/mL) compared with infants who started and stayed on LPV/r (HR=0.62, 95%CI 0.41, 0.92, p=0.02). However the hazard for confirmed failure at a higher viral load (>1000 copies/mL) was greater among children who switched to NVP compared to those who remained on LPV/r (HR=10.19, 95% CI 2.36, 43.94, p=0.002).Children undergoing an induction-maintenance ART approach with a 4-drug NNRTI-based regimen for 36 weeks, followed by 3-drug ART, had significantly greater CD4 rise than children receiving a standard 3-drug NNRTI-based ART at 36 weeks (mean difference 1.70 [95%CI 0.61, 2.79] p=0.002) and significantly better viral load response at 24 weeks (OR 1.99 [95%CI 1.09, 3.62] p=0.02). However, the immunological and virological benefits were short-term.The one trial of treatment interruption that compared children initiating continuous ART from infancy with children interrupting ART was terminated early because the duration of treatment interruption was less than 3 months in most infants. Children interrupting treatment had similar growth and occurrence of serious adverse events as those in the continuous arm.

AUTHORS' CONCLUSIONS

ART initiation in asymptomatic children under 1 year of age reduces morbidity and mortality, but it remains unclear whether there are clinical benefits to starting ART in asymptomatic children diagnosed with HIV infection between 1-3 years.The available evidence shows that a LPV/r-based first-line regimen is more efficacious than a NVP-based regimen, regardless of PMTCT exposure status. New formulations of LPV/r are urgently required to enable new WHO recommendations to be implemented. An alternative approach to long-term LPV/r is substituting LPV/r with NVP once virological suppression is achieved. This strategy looked promising in the one trial undertaken, but may be difficult to implement in the absence of routine viral load testing.A 4-drug induction-maintenance approach showed short-term virological and immunological benefits during the induction phase but, in the absence of sustained benefits, is not recommended as a routine treatment strategy. Treatment interruption following early ART initiation in infancy was challenging for children who were severely immunocompromised in the context of poor clinical immunological condition at ART initiation due to the short duration of interruption, and is therefore not practical in ART treatment programmes where close monitoring is not feasible.

Long-term effectiveness of combination antiretroviral therapy and prevalence of HIV drug resistance in HIV-1-infected children and adolescents in Rwanda

OBJECTIVE

To determine the long-term outcomes of treatment and prevalence of genotypic drug resistance in children and adolescents on combination antiretroviral therapy.

METHODS

A cross-sectional study (September 2009 to October 2010) in which clinical, immunologic and virologic outcomes were assessed at a single-study visit and through patient records in a cohort of HIV-infected children and adolescents. Risk factors for clinical and immunologic responses and virologic outcome were evaluated using logistic regression, and the accuracy of clinical and immunologic criteria in identifying virologic failure was assessed.

RESULTS

Four hundred twenty-four patients were enrolled with a median age of 10.8 years (range: 1.7-18.8) and a median duration on combination antiretroviral therapy of 3.4 years (range: 1.0-8.1). Thirty-three percent were stunted and 17% underweight. Eighty-four percent (95% confidence interval: 79-87) of children >5 years had CD4 ≥350 cells/mm and in 74% (95% confidence interval: 62-84) of younger children CD4% was ≥25. CD4 values and age at combination antiretroviral therapy initiation were independently associated with CD4 outcomes; 124 (29%) had HIV-1 RNA ≥1000 copies/mL, with no significant predictors. Sensitivity for weight-for-age and height-for-age and CD4 cells (<350/mm) remained under 50% (15-42%); CD4 cells showed the best specificity, ranging from 91% to 97%. Of 52 samples tested, ≥1 mutations were observed in 91% (nucleoside reverse transcriptase inhibitors) and 95% (non-nucleoside reverse transcriptase inhibitors); 1 to 2 thymidine analogue-associated mutations were detected in 16 (31%) and ≥3 thymidine analogue-associated mutations in 7 (13%).

CONCLUSION

Nearly 1 in 3 children showed virologic failure, and >10% of the subgroup of children with treatment failure in whom genotyping was performed demonstrated multiple HIV drug resistance mutations. Neither clinical condition nor CD4 cells were good indicators for treatment failure.

Incidence and risk factors for first line anti retroviral treatment failure among Ugandan children attending an urban HIV clinic

Background

Early recognition of antiretroviral therapy (ART) failure in resource limited settings is a challenge given the limited laboratory facilities and trained personnel. This study aimed at describing the incidence, risk factors and the resistance associated mutations (RAMs) of first line treatment failure among HIV-1-infected children attending the Joint Clinical Research Centre (JCRC), Kampala, Uganda.

Methods

A retrospective cohort of 701 children who had been initiated on ART between January 2004 and September 2009 at the JCRC was studied. Data of children aged 6 months up to 18 years who had been started on ART for at least 6 months was extracted from the clinic charts. The children who failed the first-line ART were taken as cases and those who did not fail as the controls. Data was analysed using STATA version10.

Results

Of 701 children, 240(34%) failed on first line ART (cases) and 461(66%) did not fail (controls). The overall median time (IQR) to first line ART failure was 26.4 (18.9 – 39.1) months. The factors associated with treatment failure were poor adherence [(OR = 10, 95 CI: 6.4 – 16.7) p < 0.001], exposure to single dose nevirapine (sdNVP) [(OR = 4.2, 95% CI:1.8-9.4), p = 0.005] and a NVP containing regimen [(OR = 2.2,95% CI:1.4-3.6), p < 0.001]. Of 109 genotypic resistance profiles analyzed, the commonest non nucleoside reverse transcriptase inhibitor (NNRTI) resistance associated mutations (RAM) were: K103N (59; 54%)), Y181C (36; 27%)) and G190A (26; 24%)) while the commonest nucleoside reverse transcriptase inhibitor (NRTI) RAM was the M184V (89; 81%). Thymidine analogue- mutations (TAMs) were detected in 20% of patients.

Conclusions

One in three children on first-line ART are likely to develop virological treatment failure after the first 24 months of therapy. Poor adherence to ART, a NVP based first-line regimen, prior exposure to sdNVP were associated with treatment failure.

The changing epidemiology of the global paediatric HIV epidemic: keeping track of perinatally HIV-infected adolescents

The global paediatric HIV epidemic is shifting into a new phase as children on antiretroviral therapy (ART) move into adolescence and adulthood, and face new challenges of living with HIV. UNAIDS reports that 3.4 million children aged below 15 years and 2 million adolescents aged between 10 and 19 years have HIV. Although the vast majority of children were perinatally infected, older children are combined with behaviourally infected adolescents and youth in global reporting, making it difficult to keep track of their outcomes. Perinatally HIV-infected adolescents (PHIVA) are a highly unique patient sub-population, having been infected before development of their immune systems, been subject to suboptimal ART options and formulations, and now face transition from complete dependence on adult caregivers to becoming their own caregivers. As we are unable to track long-term complications and survival of PHIVA through national and global reporting systems, local and regional cohorts are the main sources for surveillance and research among PHIVA. This global review will utilize those data to highlight the epidemiology of PHIVA infection, treatment challenges and chronic disease risks. Unless mechanisms are created to count and separate out PHIVA outcomes, we will have few opportunities to characterize the negative consequences of life-long HIV infection in order to find ways to prevent them.

Clinical implications of HIV-1 minority variants

Technologic advances in human immunodeficiency virus type 1 (HIV-1) sequencing have revolutionized the study of antiretroviral drug resistance and are increasingly moving from the laboratory to clinical practice. These techniques are able to detect HIV-1 drug resistance mutations present at low frequencies not detectable by current HIV-1 genotyping assays. For a number of commonly used antiretroviral medications, such as nonnucleoside reverse transcriptase inhibitors, the detection of these drug-resistant minority variants significantly increases the risk of treatment failure. The level of evidence, however, is insufficient to determine the impact of HIV-1 minority variants for several other classes of antiretroviral medications. Clinicians should be aware of the novel technologies that are moving into routine clinical use and the clinical implications of HIV-1 minority variants. Additional studies are needed to determine the optimal platform for clinical application of these new technologies and to provide guidance to clinicians on the type and frequency of clinically important HIV-1 minority variants.

Surveillance of HIV drug resistance in children receiving antiretroviral therapy: a pilot study of the World Health Organization's generic protocol in Maputo, Mozambique

Between 2007 and 2008, the Mozambique Ministry of Health conducted an assessment of human immunodeficiency virus drug resistance (HIVDR) using World Health Organization (WHO) methods in a cohort of children initiating antiretroviral therapy (ART) at the main pediatric ART referral center in Mozambique. It was shown that prior to ART initiation 5.4% of children had HIVDR that was associated with nevirapine perinatal exposure (P < .001). Twelve months after ART initiation, 77% had viral load suppression (<1000 copies/mL), exceeding the WHO target of ≥ 70%; 10.3% had HIVDR at 12 months. Baseline HIVDR (P = .04), maternal prevention of mother-to-child transmission (P = .02), and estimated days of missed medication (P = .03) predicted HIVDR at 12 months. As efforts to eliminate pediatric AIDS are intensified, implementation of ritonavir-boosted protease inhibitor regimens in children with prevention of mother-to-child transmission exposure may reduce risk of virological failure in our setting.

Low-frequency nevirapine resistance at multiple sites may predict treatment failure in infants on nevirapine-based treatment

BACKGROUND

Resistance commonly arises in infants exposed to single-dose nevirapine (sdNVP) for prevention of mother to child transmission. Although K103N and Y181C are common following sdNVP, multiple other mutations also confer NVP resistance. It remains unclear whether specific NVP resistance mutations or combinations of mutations predict virologic failure in infants when present at low frequencies before NVP-based treatment.

METHODS

Twenty sdNVP-exposed infants who were subsequently treated with NVP-based highly active antiretroviral therapy were examined. Pretreatment plasma samples were tested for the presence of NVP resistance mutations by allele-specific polymerase chain reaction for K103N and Y181C and ultradeep pyrosequencing (UDPS) for all primary NVP mutations. Viral levels were determined every 3 months for up to 24 months on NVP-highly active antiretroviral therapy. Cox proportional hazard models were used to determine correlates of viral failure.

RESULTS

The NVP resistance mutations K103N or Y181C were detected in pretreatment plasma samples in 6 infants by allele-specific polymerase chain reaction. NVP resistance at these or other sites was detectable by UDPS in 10 of 20 infants tested. Virologic failure occurred in 50% of infants with any NVP resistance mutations detected, whereas only 20% of infants without resistance experienced viral failure, but the difference was not significant (P = 0.19). An increase in the number of NVP resistance mutations detectable by UDPS in an infant was significantly associated with an increased risk of virologic failure [HR = 1.79 (95% confidence interval: 1.07 to 2.99), P = 0.027].

CONCLUSIONS

Low frequencies of multiple NVP resistance mutations, in addition to K103N and Y181C, present in infants before NVP-based treatment may predict treatment outcome.

Toxic epidermal necrolysis and Stevens-Johnson syndrome in South Africa: a 3-year prospective study

BACKGROUND

Toxic Epidermal Necrolysis (TEN) and Stevens-Johnson syndrome (SJS) remain feared medication-related reactions. HIV infection and tuberculosis predispose to drug eruptions, yet there is a paucity of data on TEN/SJS in populations with high prevalences of both diseases.

AIM

The aim of this prospective observational study was to describe the features and outcomes of patients admitted with TEN/SJS at a large academic hospital in South Africa. We aimed to identify poor prognostic indicators and to validate the use of the TEN-specific severity-of-illness score (SCORTEN) in this population.

METHODS

All patients admitted with TEN/SJS over a 3-year period were enrolled. Disease severity was graded according to percentage skin involved and SCORTEN. Co-morbid diagnoses, clinical features, investigations, complications and outcomes were noted.

RESULTS

75 patients (39.9 ± 10.6 years, 16 males, 59 HIV positive) were classified as TEN (n  = 42), TEN/SJS overlap (n = 11) and SJS (n = 22). Twenty-four percent died, most from refractory septic shock. Non-survivors had a higher mean SCORTEN on Days 1 and 3 (1.89 vs. 1.04, P = 0.006 and 2.27 vs. 0.90, P < 0.001). A SCORTEN ≥2 on Days 1 and 3 predicted non-survival (OR = 2.94, P = 0.047; OR = 7.45, P < 0.001). Other predictors of non-survival included HIV infection (OR = 6.01, P = 0.058), HIV-tuberculosis co-infection (OR = 8.5, P < 0.001), ≥40% skin involvement (OR = 20.27, P < 0.001), anaemia (OR = 4.68, P = 0.005), hypoalbuminemia (OR = 8.5, P = 0.001) and severe sepsis (OR = 71.09, P < 0.001).

CONCLUSION

Most patients with TEN/SJS were HIV positive and female. We validated the use of SCORTEN and identified several prognostic indicators, most significant being HIV-tuberculosis co-infection, ≥40% skin involvement and severe sepsis.

Effectiveness of antiretroviral therapy in HIV-infected children under 2 years of age

BACKGROUND

In the absence of antiretroviral therapy (ART), over 50% of HIV-infected infants progress to AIDS and death by 2 years of age. However, there are challenges to initiate ART in early life, including the possibility of drug resistance in the context of prevention of mother-to-child transmission (PMTCT) programs, a paucity of drug choices , uncertain dosing for some medications and long-term toxicities. Key management decisions include when to start ART, what regimen to start, and whether and when to switch or interrupt therapy. This review aims to summarize the currently available evidence on this topic and inform the ART management in HIV-infected children less than 2 years of age.

OBJECTIVES

To evaluate 1) when to start ART in young children; 2) what ART to start with, comparing first-line non-nucleoside reverse transcriptase inhibitor (NNRTI) and PI-based regimens; and 3) whether and when ART should be stopped or switched from a PI-based regimen to an NNRTI-based regimen.

SEARCH METHODS

We searched for published studies in the Cochrane HIV/AIDS Review Group Trials Register, The Cochrane Library, Pubmed, EMBASE and CENTRAL. We screened abstracts from relevant conference proceedings and searched for unpublished and ongoing trials in clinical trial registries (ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform).

SELECTION CRITERIA

We identified RCTs that recruited perinatally HIV-infected children under 2 years of age without restriction of setting. We rejected trials that did not include children less than 2 years of age, or did not evaluate either timing of ART initiation, choice of drug regimen or treatment switch/interruption strategy.

DATA COLLECTION AND ANALYSIS

Two reviewers independently applied study selection criteria, assessed study quality and extracted data. Effects were assessed using the hazard ratio (HR) for time-to-event outcomes, relative risk for dichotomous outcomes and weighted mean difference for continuous outcomes.

MAIN RESULTS

Of 1921 records retrieved, 5 studies were eligible for inclusion in the review, addressing when to start treatment (n=2), what to start (n=2) and whether to switch regimen (n=1). Three ongoing studies that address the question of treatment interruption were also identified.Early infant treatment was associated with a 75% reduction (HR=0.25; 95%CI 0.12-0.51; p=0.0002) in mortality or disease progression in the one trial with sufficient power to address this question. In a smaller trial,median CD4 cell count was not significantly different between early and deferred treatment groups 12 months after ART.Regardless of previous exposure to nevirapine for PMTCT, the hazard for treatment failure was 2.01 (95%CI 1.47, 2.77) times higher in children starting ART with a NVP-based regimen compared to those starting with a LPV/r-based regimen (p<0.0001) with no clear difference in effect by age group. The hazard for virological failure was overall 2.28 (95%CI 1.55, 3.34) times higher for children starting ART with a NVP-based regimen compared to those starting with a LPV/r-based regimen (p=0.0005) with a larger difference in time to virological failure (or death) between the NVP and LPV/r-based regimens when ART was initiated in the first year of life. By contrast, increases in weight z-score (MD=0.37, 95%CI 0.08, 0.65, p=0.01) and height z-score (MD=0.23, 95%CI 0.04, 0.42, p=0.02) were larger in the NVP arm compared to the LPV/r arm .Infants starting on a LPV/r regimen but who then switched to a NVP-based regimen after a median time of 9 months on LPV/r were less likely to develop virological failure (defined as at least one VL greater than 50 copies/mL) compared with infants who started and stayed on LPV/r (HR=0.62, 95%CI 0.41, 0.92, p=0.02). However the hazard for confirmed failure at a higher viral load (>1000 copies/mL) was higher among children who switched to NVP compared to those who remained on LPV/r (HR=10.19, 95% CI 2.36, 43.94, p=0.002).

AUTHORS' CONCLUSIONS

Immediate ART reduces morbidity and mortality among infants and may improve neurodevelopmental outcome. However It remains unclear whether all children diagnosed with HIV infection between 1-2 years of age should start ART, as has been recommended by the World Health Organization on practical grounds.The available evidence suggests that a LPV/r-based first-line regimen is more potent than NVP, regardless of PMTCT exposure status. However, this finding provides a dilemma to policy-makers because higher cost, poor palatability, inconvenient formulation and cold chain requirements make LPV/r a more costly and challenging first-line regimen. An alternative approach to long-term LPV/r is switching to NVP (maintaining the NRTI backbone) once virological suppression is achieved. This strategy looked promising in the one trial undertaken, but may be difficult to implement in the absence of VL testing. Ongoing trials are exploring the possibility of starting early ART and interrupting treatment beyond the critical period of rapid disease progression and neurological development. Further evidence is urgently required to better inform policy on first-line treatment recommendations in young children and more robust data addressing non-virological outcomes are also needed.

Nevirapine versus ritonavir-boosted lopinavir for HIV-infected children

BACKGROUND

Nevirapine-based antiretroviral therapy is the predominant (and often the only) regimen available for children in resource-limited settings. Nevirapine resistance after exposure to the drug for prevention of maternal-to-child human immunodeficiency virus (HIV) transmission is common, a problem that has led to the recommendation of ritonavir-boosted lopinavir in such settings. Regardless of whether there has been prior exposure to nevirapine, the performance of nevirapine versus ritonavir-boosted lopinavir in young children has not been rigorously established.

METHODS

In a randomized trial conducted in six African countries and India, we compared the initiation of HIV treatment with zidovudine, lamivudine, and either nevirapine or ritonavir-boosted lopinavir in HIV-infected children 2 to 36 months of age who had no prior exposure to nevirapine. The primary end point was virologic failure or discontinuation of treatment by study week 24.

RESULTS

A total of 288 children were enrolled; the median percentage of CD4+ T cells was 15%, and the median plasma HIV type 1 (HIV-1) RNA level was 5.7 log(10) copies per milliliter. The percentage of children who reached the primary end point was significantly higher in the nevirapine group than in the ritonavir-boosted lopinavir group (40.8% vs. 19.3%; P<0.001). Among the nevirapine-treated children with virologic failure for whom data on resistance were available, more than half (19 of 32) had resistance at the time of virologic failure. In addition, the time to a protocol-defined toxicity end point was shorter in the nevirapine group (P=0.04), as was the time to death (P=0.06).

CONCLUSIONS

Outcomes were superior with ritonavir-boosted lopinavir among young children with no prior exposure to nevirapine. Factors that may have contributed to the suboptimal results with nevirapine include elevated viral load at baseline, selection for nevirapine resistance, background regimen of nucleoside reverse-transcriptase inhibitors, and the standard ramp-up dosing strategy. The results of this trial present policymakers with difficult choices. (Funded by the National Institute of Allergy and Infectious Diseases and others; P1060 ClinicalTrials.gov number, NCT00307151.).

HIV-1 phenotypic reverse transcriptase inhibitor drug resistance test interpretation is not dependent on the subtype of the virus backbone

To date, the majority of HIV-1 phenotypic resistance testing has been performed with subtype B virus backbones (e.g. HXB2). However, the relevance of using this backbone to determine resistance in non-subtype B HIV-1 viruses still needs to be assessed. From 114 HIV-1 subtype C clinical samples (36 ARV-naïve, 78 ARV-exposed), pol amplicons were produced and analyzed for phenotypic resistance using both a subtype B- and C-backbone in which the pol fragment was deleted. Phenotypic resistance was assessed in resulting recombinant virus stocks (RVS) for a series of antiretroviral drugs (ARV's) and expressed as fold change (FC), yielding 1660 FC comparisons. These Antivirogram® derived FC values were categorized as having resistant or sensitive susceptibility based on biological cut-off values (BCOs). The concordance between resistance calls obtained for the same clinical sample but derived from two different backbones (i.e. B and C) accounted for 86.1% (1429/1660) of the FC comparisons. However, when taking the assay variability into account, 95.8% (1590/1660) of the phenotypic data could be considered as being concordant with respect to their resistance call. No difference in the capacity to detect resistance associated with M184V, K103N and V106M mutations was noted between the two backbones. The following was concluded: (i) A high level of concordance was shown between the two backbone phenotypic resistance profiles; (ii) Assay variability is largely responsible for discordant results (i.e. for FC values close to BCO); (iii) Confidence intervals should be given around the BCO's, when assessing resistance in HIV-1 subtype C; (iv) No systematic resistance under- or overcalling of subtype C amplicons in the B-backbone was observed; (v) Virus backbone subtype sequence variability outside the pol region does not contribute to phenotypic FC values. In conclusion the HXB2 virus backbone remains an acceptable vector for phenotyping HIV-1 subtype C pol amplicons.

Switching children previously exposed to nevirapine to nevirapine-based treatment after initial suppression with a protease-inhibitor-based regimen: long-term follow-up of a randomised, open-label trial

BACKGROUND

Protease-inhibitor-based treatment is recommended as first-line for infants infected with HIV who have been previously exposed to nevirapine prophylaxis. However, long-term use poses adherence challenges, is associated with metabolic toxic effects, restricts second-line options, and is costly. We present the long-term outcomes of switching nevirapine-exposed children to nevirapine-based treatment after effective suppression of virus replication with a protease-inhibitor-based regimen.

METHODS

We did a randomised trial to compare long-term viral suppression with nevirapine-based versus protease-inhibitor-based (ritonavir-boosted lopinavir) treatment in children who had achieved suppression with protease-inhibitor-based treatment. Randomisation (1:1) was by cohort blocks of variable size between eight and 12. Eligible children were younger than 24 months who were previously exposed to nevirapine for prevention of mother-to-child transmission, and achieved virological suppression of less than 400 copies per mL when treated with the regimen based on ritonavir-boosted lopinavir in Johannesburg, South Africa. We gave all drugs as liquids and adjusted doses at each visit in accordance with growth. We continued follow-up for a minimum of 90 weeks and maximum of 232 weeks after randomisation. We quantified HIV RNA every 3 months. Our primary endpoint was any viraemia greater than 50 copies per mL. Our analysis was by modified intention to treat. This study is registered with ClinicalTrials.gov, number NCT00117728.

FINDINGS

We followed up the children for a median of 156 weeks and there were three deaths in each group. Children in the switch group (Kaplan-Meier probability 0·595) were less likely to experience non-suppression greater than 50 copies per mL than in the control group (0·687; p=0·01) and had better CD4 and growth responses initially after switching (52 children in the switch group vs 66 control group met this endpoint). By 156 weeks after randomisation, more children had virological failure--which we defined as confirmed viraemia of more than 1000 copies per mL--in the switch group (22 children) than in the control group (ten children; p=0·009). We detected all 22 failures in the switch group by 52 weeks compared with five in the control group. Virological failure was related to non-adherence and pretreatment drug resistance. In children without pretreatment drug resistance, we did not identify a significant difference in virological failure between the switch (Kaplan-Meier probability 0·140) and control (0·095) groups (p=0·34; seven failures in the switch group vs five in the control group). Children in the switch group were significantly more likely to develop grade 1-3 alanine aminotransferase abnormalities over the duration of follow-up.

INTERPRETATION

Viral-load testing through 52 weeks can identify all children likely to fail this protease-inhibitor-switch strategy. Switching children once suppressed to a nevirapine-based regimen might be a valuable treatment option if adequate viral-load monitoring can be done.

FUNDING

National Institutes of Child Health and Human Development and Secure the Future Foundation.

Women and HIV: motherhood and more

PURPOSE OF REVIEW

The number of women living with HIV continues to increase globally. With the availability of efficacious antiretroviral therapy, there is a pressing need to ensure women are treated effectively throughout their life course. This article reviews information on ways that HIV affects women and discusses recent treatment and prevention approaches.

RECENT FINDINGS

Because women are at greater risk of heterosexual HIV acquisition than men, new data on biomedical approaches to prevention are of particular relevance. International guidelines for the treatment of pregnant women with HIV now place greater weight on the well being of the mother as well as the prevention of vertical transmission. Although effective HIV treatment for women is associated with better health, longer life, reduced infectiousness and prevention of acquisition of HIV, there is evidence that women experience more adverse effects, discontinue medication more frequently and have more problems with adherence than men.

SUMMARY

Efficacious anti-HIV drugs exist, but the particular circumstances for women may compromise their effectiveness. Globally, women's access to therapy remains inadequate. More data are needed about the best approaches to HIV therapy for women to include the biological, psychological, social and cultural factors that influence the way women experience HIV infection.