Efficacy, safety and pharmacokinetics of tenofovir disoproxil fumarate in virologic-suppressed HIV-infected children using weight-band dosing

Fixed-dose antiretroviral combinations in children living with human immunodeficiency virus type 1 (HIV-1): a systematic review

Fixed-Dose antiretroviral Combinations (FDCs) are the most used drug regimes in adult patients with human-immunodeficiency virus 1 infection, since they increase adherence to antiretroviral therapy and enable good quality of life. The European AIDS Clinical Society guidelines recommend the use of FDCs in paediatrics. However, the use of FDCs in paediatric population is restricted since studies in children and adolescents are mostly conducted in small sample sizes and are heterogeneous in settings and design. This systematic review aims to summarize the current knowledge about the use of FDCs in paediatric population, highlighting the relevant outcomes regarding efficacy and effectiveness, adherence, safety, and adverse events of these regimens.

Health-Related Physical Fitness Evaluation in HIV-Diagnosed Children and Adolescents: A Scoping Review

BACKGROUND

Health-related physical fitness has been widely used to investigate the adverse effects of HIV infection/ART in children and adolescents. However, methods/protocols and cut-points applied for investigating health-related physical fitness are not clear. The aim of this scoping review was to map the literature to identify gaps in knowledge regarding the methods/protocols and cut-points.

METHODS

A scoping review, following the Joana Briggs Institute (JBI) guidelines, was conducted through ten major databases. Search followed the PCC strategy to construct block of terms related to population (children and adolescents), concept (health-related physical fitness components) and context (HIV infection).

RESULTS

The search resulted in 7545 studies. After duplicate removal, titles and abstracts reading and full text assessment, 246 studies were included in the scoping review. Body composition was the most investigated component (n = 244), followed by muscular strength/endurance (n = 23), cardiorespiratory fitness (n = 15) and flexibility (n = 4). The World Health Organization growth curves, and nationals' surveys were the most reference values applied to classify body composition (n = 149), followed by internal cut-points (n = 30) and cut-points developed through small populations (n = 16). Cardiorespiratory fitness was classified through cut-points from three different assessment batteries, as well as cut-points developed through studies with small populations, muscular strength/endurance and flexibility were classified through the same cut-points from five different assessment batteries.

CONCLUSIONS

The research on muscular strength/endurance, cardiorespiratory fitness and flexibility has been scarcely explored. The lack of studies that investigated method usability as well as reference values was evidenced.

Assessing bone mineral density in children and adolescents living with HIV and on treatment with tenofovir disoproxil fumarate: a systematic review

OBJECTIVE

To investigate the impact of tenofovir disoproxil fumarate on bone mineral density and bone mineral content in children and adolescents infected with the human immunodeficiency virus.

DATA SOURCE

The search procedure was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. The search was carried out until April 2022 in Medical Literature Analysis and Retrieval System Online (Medline), Embase, Cochrane Central, Latin American and Caribbean Health Sciences Literature, Web of Science, Scopus, and MedRxiv. The combination of terms used was: (Children OR Youth OR Teenagers) AND HIV AND (Tenofovir OR "Antiretroviral therapy") AND ("Bone density" OR Osteoporosis OR Osteopenia). The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO, CRD42022312851).

DATA SYNTHESIS

The initial searches resulted in 1156 papers. After the exclusion of duplicate studies, three blinded reviewers analyzed the title and abstract of 563 papers, of which 57 remained to be read in full. Only nine papers met the eligibility criteria and were included in descriptive and risk-of-bias analyses. Regarding study design, four were cross-sectional, three were longitudinal before-after studies without a control group, and two were prospective cohorts. Among these nine papers, seven showed no significant association between tenofovir disoproxil fumarate use and reduced bone mass in young people. However, these papers did not have high methodological quality.

CONCLUSIONS

Although most of the selected papers found no harmful effect of tenofovir disoproxil fumarate on bone mass, further primary research with higher methodological quality is needed so robust scientific evidences can be obtained.

First Pharmacokinetic Data of Tenofovir Alafenamide Fumarate and Tenofovir With Dolutegravir or Boosted Protease Inhibitors in African Children: A Substudy of the CHAPAS-4 Trial

BACKGROUND

We evaluated the pharmacokinetics of tenofovir alafenamide fumarate (TAF) and tenofovir in a subset of African children enrolled in the CHAPAS-4 trial.

METHODS

Children aged 3-15 years with human immunodeficiency virus infection failing first-line antiretroviral therapy were randomized to emtricitabine/TAF versus standard-of-care nucleoside reverse transcriptase inhibitor combination, plus dolutegravir, atazanavir/ritonavir, darunavir/ritonavir, or lopinavir/ritonavir. Daily emtricitabine/TAF was dosed according to World Health Organization (WHO)-recommended weight bands: 120/15 mg in children weighing 14 to <25 kg and 200/25 mg in those weighing ≥25 kg. At steady state, 8-9 blood samples were taken to construct pharmacokinetic curves. Geometric mean (GM) area under the concentration-time curve (AUC) and the maximum concentration (Cmax) were calculated for TAF and tenofovir and compared to reference exposures in adults.

RESULTS

Pharmacokinetic results from 104 children taking TAF were analyzed. GM (coefficient of variation [CV%]) TAF AUClast when combined with dolutegravir (n = 18), darunavir/ritonavir (n = 34), or lopinavir/ritonavir (n = 20) were 284.5 (79), 232.0 (61), and 210.2 (98) ng*hour/mL, respectively, and were comparable to adult reference values. When combined with atazanavir/ritonavir (n = 32), TAF AUClast increased to 511.4 (68) ng*hour/mL. For each combination, tenofovir GM (CV%) AUCtau and Cmax remained below reference values in adults taking 25 mg TAF with a boosted protease inhibitors.

CONCLUSIONS

In children, TAF combined with boosted PIs or dolutegravir and dosed according to WHO-recommended weight bands provides TAF and tenofovir concentrations previously demonstrated to be well tolerated and effective in adults. These data provide the first evidence for use of these combinations in African children.

CLINICAL TRIALS REGISTRATION

ISRCTN22964075.

Effect of anti-retroviral regimen on proximal tubular function in Zambian adolescents and young adults living with HIV: A cross sectional study

Background: Tenofovir regimens remain the preferred formulations in the HIV guidelines for adolescents and young adults in Zambia and globally. However, some adolescents and young adults are maintained on abacavir by clinicians because of anxiety about possible proximal tubular dysfunction from tenofovir. We assessed the effect of two regimens on proximal tubular function in adolescents and young adults living with HIV. Methods: This was a cross-sectional study involving 180 participants with HIV receiving either tenofovir or abacavir for ≥12 months at the largest tertiary teaching hospital. Two first-morning urine and blood specimens were collected and analyzed for proximal tubular markers, glomerular function, electrolytes, and routine monitoring tests. Proximal tubular function was determined by measuring the fractional excretion of phosphate (FePO4). Proximal tubular dysfunction was defined by FePO4 ≥20% regardless of serum phosphate and FePO4  ≥10-20% when serum phosphate was below 0.81mmol/L. Results: The prevalence of proximal tubular dysfunction was 6% and was higher in the tenofovir group than the abacavir (10% vs. 2%, p<0.058). However, after adjusting for potential confounders, tenofovir was not associated with worse proximal tubular function. Age, urine b2-microglobulin: creatinine ratio, C-reactive protein, and urine protein: creatinine ratio was all associated with worsening proximal tubular dysfunction. Reduced estimated glomelurar filtration rate (eGFR) was found in four (2.2%) participants; three of which were on tenofovir. Conclusions: Proximal tubular dysfunction defined by FePO4 was more prevalent in the tenofovir group than the abacavir group, but not after adjusting for age. Our findings should be interpreted with caution as age differences between the two groups confounded the results.

Development and application of a pediatric mechanistic kidney model

Pediatric physiologically‐based pharmacokinetic (P‐PBPK) models have been used to predict age related changes in the pharmacokinetics (PKs) of renally cleared drugs mainly in relation to changes in glomerular filtration rate. With emerging data on ontogeny of renal transporters, mechanistic models of renal clearance accounting for the role of active and passive secretion should be developed and evaluated. Data on age‐related physiological changes and ontogeny of renal transporters were applied into a mechanistic kidney within a P‐PBPK model. Plasma concentration–time profile and PK parameters of cimetidine, ciprofloxacin, metformin, tenofovir, and zidovudine were predicted in subjects aged 1 day to 18 years. The predicted and observed plasma concentration–time profiles and PK parameters were compared. The predicted concentration–time profile means and 5th and 95th percent intervals generally captured the observed data and variability in various studies. Overall, based on drugs and age bands, predicted to observed clearance were all within two‐fold and in 11 of 16 cases within 1.5‐fold. Predicted to observed area under the curve (AUC) and maximum plasma concentration (C_max) were within two‐fold in 12 of 14 and 12 of 15 cases, respectively. Predictions in neonates and early infants (up to 14 weeks postnatal age) were reasonable with 15–20 predicted PK parameters within two‐fold of the observed. ciprofloxacin but not zidovudine PK predictions were sensitive to basal kidney uptake transporter ontogeny. The results indicate that a mechanistic kidney model accounting for physiology and ontogeny of renal processes and transporters can predict the PK of renally excreted drugs in children. Further data especially in neonates are required to verify the model and ontogeny profiles.

No Difference in Growth Outcomes up to 24 Months of Age by Duration of Exposure to Maternal Antiretroviral Therapy Among Children Who Are HIV-Exposed and Uninfected in Malawi

BACKGROUND

With the implementation of lifelong antiretroviral therapy (ART) for HIV treatment and prevention, the proportion of children exposed to ART in utero from conception is increasing. We estimated the effect of timing of ART exposure on growth of children HIV-exposed and uninfected (CHEU) up to Up to 24 months of age in Malawi.

METHODS

Data were collected from a prospective cohort of infants HIV-exposed aged 1-6 months (enrollment) and their mothers with HIV enrolled in the National Evaluation of Malawi's Prevention of Mother-to-Child Transmission of HIV Programme (2014-2018). Anthropometry was measured at enrollment, visit 1 (approximately 12 months), and visit 2 (approximately 24 months). Weight-for-age (WAZ) and length-for-age (LAZ) were calculated using the WHO Growth Standards. Multivariable mixed-effects models with linear splines for age were used to examine differences in growth by timing of ART exposure (from conception, first/second trimester, or third trimester/postpartum). Models were adjusted for confounders selected a priori guided by a conceptual framework. Hypothesized interactions and potential mediators were explored, and interactions with splines were included in final models if P < 0.1.

RESULTS

A total of 1,206 singleton CHEU and their mothers were enrolled and 563 completed the follow-up through 24 months of age. Moreover, 48% of CHEU were exposed to ART from conception, 40% from first/second trimester, and 12% from third trimester/postpartum. At enrollment, 12% of infants had low birthweight (LBW), 98% had been breastfed in past 7 days, and 57% were enrolled in an HIV care clinic. CHEU growth trajectories demonstrated cohort-wide growth faltering after the age of 12 months. Of 788 and 780 CHEU contributing to WAZ and LAZ multivariable models, respectively, there was no evidence of differences in mean WAZ or LAZ among those exposed from conception or first/second trimester vs. third trimester/postpartum and no evidence of a difference in WAZ or LAZ rate of change by timing of ART exposure (all interactions P > 1.0).

CONCLUSION

Reassuringly, ART exposure from conception was not associated with decreased WAZ or LAZ in CHEU Up 24 months of age. Overall growth trajectories suggest CHEU experience growth faltering after 12 months of age and may need support through and beyond the first 2 years of life.

Bone outcomes in virally suppressed youth with HIV switching to tenofovir disoproxil fumarate

Background

Tenofovir disoproxil fumarate (TDF) is included in first-line antiretroviral treatment (ART) for adolescents living with HIV (ALWH). Associated toxicities remain a concern.

Objective

We evaluated bone and renal safety outcomes in virologically suppressed South African ALWH after switching to TDF.

Method

We recruited virally suppressed (< 100 copies/mL) adolescents, aged 15-20 years, who switched from an abacavir (ABC)-based to a TDF-based efavirenz regimen. Bone mass and renal function were assessed at Week 0 and at Week 24 after the switch to TDF using dual-energy X-ray absorptiometry (DXA) and serum renal markers. A change in the lumbar spine (LS) and the whole-body less head (WBLH) bone mineral density (BMD) Z-scores and the estimated glomerular filtration rate (eGFR) between the two measures were compared (paired t-tests) and stratified by sex.

Results

Fifty participants (48% male), with a median duration of prior ART of 11.4 years, were enrolled. Among 47 participants with 24-week DXA results, 15 (32%) had either no change or a decreased LS-BMD after the switch, with a mean change of -1.6%. Overall, more female participants experienced this outcome: 58% versus 4%, P < 0.0001. The mean change (standard deviation) in the LS-Z-score was -0.03 (0.25) and in the WBLH-Z-score was 0.02 (0.24). A decrease in the eGFR from 132.2 to 120.4 was observed (P = 0.0003); however, the levels remained clinically acceptable.

Conclusion

South African ALWH switching from abacavir to TDF-based ART experienced statistically significant decreases in eGFR but not in LS and WBLH BMD. Female ALWH were more likely to experience a decrease in LS-BMD and may require closer monitoring.

Effect of HIV infection on growth and bone density in peripubertal children in the era of antiretroviral therapy: a cross-sectional study in Zimbabwe

Background

Faltered linear growth and pubertal delay, which are both common in children with HIV in sub-Saharan Africa, might affect adolescent bone accrual and future fragility fracture risk. We investigated the association of HIV with bone density adjusted for skeletal size in peripubertal children in Zimbabwe.

Methods

We did a cross-sectional study of baseline data from the IMVASK cohort, which enrolled children aged 8–16 years with HIV who had been taking antiretroviral therapy (ART) for at least 2 years, and children of the same age without HIV. Children with HIV were recruited from public sector HIV clinics at Parirenyatwa General Hospital and Harare Central Hospital (Harare, Zimbabwe), and children without HIV were recruited from six schools in the same suburbs that the hospitals serve. Sociodemographic, clinical, and anthropometric data were collected. Dual-energy X-ray absorptiometry (DXA) was used to measure the bone outcomes of total-body less-head bone mineral content for lean mass adjusted for height (TBLH-BMC^LBM), and lumbar spine bone mineral apparent density (LS-BMAD), and we assessed the prevalence of low TBLH-BMC^LBM and low LS-BMAD (defined by Z-scores of less than −2·0). Size adjustment techniques were used to overcome the size dependence of DXA measurement. We used linear regression models, with multiple imputation for missing data, to assess relationships between risk factors and TBLH-BMC^LBM and LS-BMAD Z-scores in children with and without HIV.

Findings

We recruited 303 children with HIV (mean age 12·4 years [SD 2·5]; 151 [50%] girls) and 306 children without HIV (mean age 12·5 years [SD 2·5]; 155 [51%] girls). In children with HIV, median age of HIV diagnosis was 3·0 years (IQR 1·2–5·8), and median ART duration was 8·1 years (6·2–9·5); for 102 (34%) children, ART included tenofovir disoproxil fumarate (TDF). Children with HIV had a higher prevalence of low TBLH-BMC^LBM Z-score than children without HIV (29 [10%] of 279 children with available data vs 18 [6%] of 292 with available data; p=0·066) and a higher prevalence of low LS-BMAD Z-score (40 [14%] of 279 vs 17 [6%] of 293 with available data; p=0·0007). HIV and male sex were associated with earlier pubertal (Tanner) stage. The negative associations between HIV and Z-scores for TBLH-BMC^LBM and LS-BMAD were more pronounced with pubertal maturation, particularly in girls. Among children with HIV, TDF exposure and orphanhood were associated with lower TBLH-BMC^LBM Z-score in confounder-adjusted analysis. Current TDF use (vs non-TDF-based ART) was associated with a reduction in TBLH-BMC^LBM Z-score of 0·41 (95% CI 0·08–0·74; p=0·015) and in LS-BMAD Z-score of 0·31 (0·08–0·69; p=0·12).

Interpretation

Despite ART, HIV is associated with substantial skeletal deficits towards the end of puberty. The extent of bone deficits associated with TDF and its widespread use in children in sub-Saharan Africa are a concern for future adult fracture risk.

Funding

Wellcome Trust.

Growth and Neurodevelopment Outcomes in HIV-, Tenofovir-, and Efavirenz-Exposed Breastfed Infants in the PMTCT Option B+ Program in Malawi

BACKGROUND

Pregnant and breastfeeding women in Option B+ in Malawi received antiretroviral drugs (ARVs) containing efavirenz (EFV) and tenofovir disoproxil fumarate (TDF). However, effects on growth, renal, bone metabolism, and neurodevelopment of long-term exposure to low doses of these drugs through breast milk in HIV-exposed infants are unclear.

METHODS

Prospective cohorts of TDF-and-EFV-exposed and TDF-and-EFV-unexposed breastfed infants of HIV-infected and HIV-uninfected mothers in Option B+ were recruited in 2:1 ratio, respectively, followed from birth to 18 months. Infants with low birth weight, premature birth, and congenital abnormalities were excluded. Anthropometrics were assessed at birth, 6 weeks, 3, 6, 12, and 18 months. Neurodevelopment assessments used the Bayley Scales of Infant and Toddler Development III from 6 weeks. Creatinine, alkaline phosphatase, and phosphorus were assessed at 3, 6, and 12 months.

RESULTS

Of 260 HIV-and-ARV-exposed and 125 HIV-and-ARV-unexposed infants enrolled at birth, 87% and 57%, 78% and 59%, 77% and 54%, 73% and 51%, and 65% and 43% completed 6-weeks, 3, 6, 12, and 18 months visits, respectively. There were no significant differences in the mean Z-scores for length-for-age, weight-for-age, weight-for-length, mid-upper arm circumference-for-age, and head circumference-for-age between groups except at 6-weeks for length-for-age. No bone fractures occurred. Neurodevelopment outcomes were similar between groups. Of creatinine, alkaline phosphatase, and serum phosphate measurements, 1.7%, 2.6%, and 3.3% reached any toxicity levels grades 1-4, respectively, with no differences between groups.

CONCLUSION

Long-term exposure to EFV and TDF through breastfeeding in infants of HIV-infected mothers does not seem to result in significant growth, neurodevelopment, renal, or bone adverse outcomes. Data support safety of breastfeeding through 18 months within the Option B+ program.

The IMpact of Vertical HIV infection on child and Adolescent SKeletal development in Harare, Zimbabwe (IMVASK Study): a protocol for a prospective cohort study

INTRODUCTION

The scale-up of antiretroviral therapy (ART) across sub-Saharan Africa (SSA) has reduced mortality so that increasing numbers of children with HIV (CWH) are surviving to adolescence. However, they experience a range of morbidities due to chronic HIV infection and its treatment. Impaired linear growth (stunting) is a common manifestation, affecting up to 50% of children. However, the effect of HIV on bone and muscle development during adolescent growth is not well characterised. Given the close link between pubertal timing and musculoskeletal development, any impairments in adolescence are likely to impact on future adult musculoskeletal health. We hypothesise that bone and muscle mass accrual in CWH is reduced, putting them at risk of reduced bone mineral density (BMD) and muscle function and increasing fracture risk. This study aims to determine the impact of HIV on BMD and muscle function in peripubertal children on ART in Zimbabwe.

METHODS AND ANALYSIS

Children with (n=300) and without HIV (n=300), aged 8-16 years, established on ART, will be recruited into a frequency-matched prospective cohort study and compared. Musculoskeletal assessments including dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, grip strength and standing long jump will be conducted at baseline and after 1 year. Linear regression will be used to estimate mean size-adjusted bone density and Z-scores by HIV status (ie, total-body less-head bone mineral content for lean mass adjusted for height and lumbar spine bone mineral apparent density. The prevalence of low size-adjusted BMD (ie, Z-scores <-2) will also be determined.

ETHICS AND DISSEMINATION

Ethical approval for this study has been granted by the Medical Research Council of Zimbabwe and the London School of Hygiene and Tropical Medicine Ethics Committee. Baseline and longitudinal analyses will be published in peer-reviewed journals and disseminated to research communities.

Complications of Treatment in Youth with HIV

While combination antiretroviral therapy allows HIV-infected patients to have life expectancies similar to that of the general population, it may also contribute to the development of co-morbidities, such as cardiovascular disease and osteoporosis. Such complications could compromise long-term quality of life, especially in HIV-infected youth whose lifetime cumulative exposure to antiretrovirals is likely to be many decades. Recent studies continue to demonstrate abnormalities associated with antiretroviral therapy, although clinical manifestations are rare in this younger population, especially with modern antiretrovirals. The purpose of this paper is to review the most recent literature on complications of treatment in youth with HIV.

A 10-year follow-up of bone mineral density in HIV-infected youths receiving tenofovir disoproxil fumarate

BACKGROUND

The use of tenofovir disoproxil fumarate (TDF) has simplified the antiretroviral regimen for HIV-infected patients and improved their compliance with treatment, but it has been associated with decreased bone mineral density (BMD) in adult patients, and data in pediatric patients are debated. The aim of the current study was to assess the long-term effect of TDF on BMD in young patients.

METHODS

BMD was measured at the lumbar spine and in the whole skeleton in 26 HIV-infected youths (13 female and 13 male, aged 5 to 17 years at baseline). BMD was measured yearly for 10 years as part of standard care. BMD changes were compared with those calculated from 202 healthy subjects aged 3 to 24 years.

FINDINGS

All patients had good control of the infection during the 10-year study. BMD measurements changed significantly (P <0 ⋅ 0001) in HIV-infected youths. The mean annual BMD increment at the lumbar spine was 0 ⋅ 046 (0 ⋅ 006) g/cm² and 0 ⋅ 042 (0 ⋅ 006) g/cm² in males and females, respectively. The differences between the slopes of patients and healthy controls were not significant. The annual BMD increment of the whole skeleton was 0 ⋅ 030 (0 ⋅ 005) g/cm² in males and 0 ⋅ 019 (0 ⋅ 004) g/cm² in females. The slopes of BMD changes of patients and healthy controls did not differ significantly.

INTERPRETATION

These data indicate that treatment with a TDF-containing antiretroviral regimen does not impair BMD in young patients with HIV-infection. Larger studies are needed to confirm these results.

Safety, efficacy, and pharmacokinetics of single-tablet elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide in virologically suppressed, HIV-infected children: a single-arm, open-label trial

BACKGROUND

No once-daily single-tablet regimen is available for HIV-infected children under 12 years. The single-tablet, fixed-dose combination of elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide is a once-daily, integrase strand transfer inhibitor-based regimen approved in the USA and European Union for individuals aged 12 years or older. In this study, we aimed to assess the pharmacokinetics, safety, and efficacy of this regimen in virologically suppressed, HIV-infected children.

METHODS

In this single-arm, open-label trial, we enrolled virologically suppressed, HIV-infected children from five hospital clinics in Uganda, the USA, and Thailand. Eligible participants were aged 6-11 years, weighed 25 kg or more, had virological suppression (<50 copies of HIV-1 RNA per mL) on a stable regimen for at least 6 months, CD4 count of more than 100 cells per μL, and no history of resistance to elvitegravir, emtricitabine, tenofovir alafenamide, or tenofovir. All participants received the available fixed-dose oral formulation of elvitegravir 150 mg, cobicistat 150 mg, emtricitabine 200 mg, and tenofovir alafenamide 10 mg once per day. Primary outcomes were the pharmacokinetic parameters area under the curve (AUC) concentration at the end of the dosing interval (AUC_tau) for elvitegravir and the AUC from time zero to the last quantifiable concentration (AUC_last) of tenofovir alafenamide, treatment-emergent serious adverse events, and all treatment-emergent adverse events. Results from baseline to week 24 are reported, unless specified otherwise. Primary and safety analyses included all enrolled participants who received one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT01854775.

FINDINGS

Between July 27 and Sept 28, 2015, we screened 26 children, of whom 23 were enrolled and initiated treatment. Median age was 10 years (IQR 8-11), median weight was 30·5 kg (IQR 27·5-33·0), and all participants had virological suppression. The mean AUC_tau of elvitegravir was 33 814 ng × h/mL (coefficient of variation 58%), and the mean AUC_last of tenofovir alafenamide was 333 ng × h/mL (45%). Exposures to elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide were higher, but modestly so, than those previously reported in adults. All 23 participants tolerated the regimen well; there were no serious adverse events or adverse event-related discontinuations. All participants maintained virological suppression (HIV-1 RNA <50 copies per mL) at week 24. CD4 count decreased by a median of -130 cells per μL (range -472 to 266) with little change in CD4 cell percentage (-2·1%, range -8·4 to 5·9).

INTERPRETATION

The fixed-dose combination of elvitegravir, cobicistat, emtricitabine, and tenofovir alafenamide was efficacious and well tolerated in virologically suppressed, HIV-infected children. Although plasma exposure of all components was higher than has been reported in adults, there were no safety concerns and the overall bone and renal safety profile was favourable. These data support the use of this regimen in children at least 25 kg in weight.

FUNDING

Gilead Sciences.

Low Bone Mineral Density in Vertically HIV-infected Children and Adolescents: Risk Factors and the Role of T-cell Activation and Senescence

BACKGROUND

Our aim was to determine the prevalence and risk factors associated with low bone mineral density (BMD) in vertically HIV-infected patients and to investigate whether low BMD is related to immune activation and senescence induced by HIV infection.

METHODS

A cross-sectional study was performed in 98 vertically HIV-infected patients. BMD was measured by dual-energy radiograph absorptiometry at lumbar spine. Height adjustment of BMD Z score was performed using height-for-age Z score. T-cell immune activation and senescence were analyzed in a subgroup of 54 patients by flow cytometry.

RESULTS

Median age was 15.9 years, 71.4% were Caucasian, 99% received antiretroviral therapy and 80.6% had undetectable viral load. Low BMD (BMD Z score ≤ -2) was present in 15.3% of cases, but after height adjustment in 4.1% of cases. Height-adjusted BMD Z score was positively correlated with body mass index Z score, CD4/CD8 ratio and nadir CD4, and inversely with duration of severe immunosuppression and parathyroid hormone values. In the multivariate model including age, gender, ethnicity, encephalopathy, Tanner stage, nadir CD4, duration of viral suppression, CD4 count, CD4/CD8 ratio, body mass index, cumulative duration of antiretroviral therapy, tenofovir and protease inhibitors exposure, nadir CD4 was independently associated to height-adjusted BMD Z score. No association was found between height-adjusted BMD Z score and T-cell activation or senescence.

CONCLUSIONS

The prevalence of low BMD in vertically HIV-infected patients was low after height adjustment. Nadir CD4, but not T-cell activation or senescence, was an independent predictor for low BMD. Larger and prospective studies are needed to achieve better knowledge of the pathogenesis of low BMD in vertical HIV infection.

Bone health in HIV-infected children and adolescents

PURPOSE OF REVIEW

Chronic HIV infection and exposure to antiretroviral therapy compromises bone health in children and adolescents, potentially impacting their long-term quality of life. Thus, the purpose of this article is to review the most recent literature on this topic in HIV-infected children and adolescents.

RECENT FINDINGS

Recent studies continue to demonstrate bone abnormalities in HIV-infected children and adolescents, whether HIV is acquired perinatally or during adolescence. Researchers have employed new modalities, both high tech and those that can be utilized in resource-limited settings, to better assess bone health. New data suggest that this population may also be experiencing an increase incidence of fractures, and they may not acquire the same peak bone mass as their HIV-uninfected counterparts. Reassuringly, however, in-utero tenofovir exposure does not appear to have a significant impact on bone health in HIV-exposed, uninfected infants.

SUMMARY

HIV-infected children and adolescents are exposed to HIV and antiretroviral therapy for many decades starting early in life and during the most critical time for skeletal growth and bone mass accrual. Recent findings underscore the need for further research on bone in this population. Longitudinal studies are especially needed to evaluate long-term risk of osteoporosis and fracture.

HIV and Bone Complications: Understudied Populations and New Management Strategies

The higher risk of osteoporosis and fracture associated with HIV infection and certain antiretrovirals has been well established and the need for risk stratification among older adults increasingly recognized. This review focuses upon emerging data on bone complications with HIV/HCV coinfection, in children and adolescents, and with pre-exposure prophylaxis (PrEP), as well as new management strategies to minimize the negative effects of ART on bone.

An update on the HIV treatment cascade in children and adolescents

PURPOSE OF REVIEW

To provide an update on the HIV treatment cascade in children and adolescents. We reviewed the literature on the steps in the cascade, for the period 2014-2015.

RECENT FINDINGS

There remains high attrition of children with regards to early testing and linking those patients who are positive to early treatment. Barriers to screening and testing in children and adolescents are multifactorial. Linkage to pre-antiretroviral therapy care and retention in care are the main steps at which attrition occurs. There are a number of new formulations available for use in adolescents and children which offer more options for antiretroviral therapy treatment. Adherence levels appear to be reasonable in Africa and Asia; however, achieving viral load suppression remains a challenge.

SUMMARY

We have a long way to go to achieve decreased attrition at each step of the cascade and retain patients in care. Recent improvements in each step of the cascade are bringing us closer to achieving treatment success.

Paediatric HIV: Progress on Prevention, Treatment and Cure

PURPOSE OF REVIEW

This review provides an update on current developments with prevention, treatment and cure strategies in the field of pediatric HIV.

RECENT FINDINGS/SUMMARY

There has been tremendous progress in the prevention and treatment of pediatric HIV infection. With new strategies for prevention of mother-to-child transmission, we are growing ever closer towards elimination of pediatric HIV, though challenges with retention of pregnant woman and their HIV-exposed infants remain. Ongoing vigilance regarding the potential hazards of in utero ART exposure to infants continues with no significant alarms yet identified. Though cure has not been achieved, evidence of the impact of early treatment on reducing HIV-1 reservoir size with subsequent prolonged remission has enlivened efforts to rapidly identify and treat HIV-infected newborns. There is an increasing array of treatment options for pediatric patients and reassuring evidence regarding long-term complications of ART. Unfortunately, despite evidence suggesting the benefit of early treatment, timely identification and treatment of children remains a challenge. Better strategies for effective case-finding and engagement in care are urgently needed in addition to an improved understanding of how to retain HIV-positive children and adolescents on treatment. However, further emboldened by recent international commitments and robust global support, the future is hopeful.