Neurologic Outcomes in HIV-Exposed/Uninfected Infants Exposed to Antiretroviral Drugs During Pregnancy in Latin America and the Caribbean

Fetal growth assessed via ultrasound in relation to maternal HIV infection status and antiretroviral regimens

OBJECTIVE

To evaluate effects of maternal HIV and antiretroviral treatment (ART) on intrauterine fetal growth.

DESIGN

Prospective cohort studies of HIV and ZIKA infection among women living with HIV (WLHIV) and women not living with HIV (WNLHIV) conducted in Brazil and the US from 2016 to 2020.

METHODS

We evaluated fetal growth via repeated ultrasounds and calculated z scores for fetal growth measures using Intergrowth-21st standards among women with singleton pregnancies. Adjusted linear mixed models were fit for each fetal growth z score by HIV status. Among WLHIV, we compared fetal growth z scores by the most common maternal ART regimens, stratified by timing of ART initiation.

RESULTS

We included 166 WLHIV and 705 WNLHIV; none had Zika infection. The z scores were similar for WLHIV and WNLHIV for femur length (latest third trimester median = 1.08) and estimated fetal weight (median ≈0.60); adjusted mean differences in fetal weight z scores by HIV status were less than 0.1 throughout gestation. Other fetal growth measurements were lower for WLHIV than WNLHIV early in gestation but increased more rapidly over gestation. Among WLHIV not on ART at conception, adjusted mean z scores were generally similar across regimens initiated during pregnancy but somewhat lower for atazanavir-based regimens for biparietal diameter compared with efavirenz-based or raltegravir-based regimens. Among WLHIV on ART at conception, mean z scores were similar across ART regimens.

CONCLUSION

Within our cohorts, fetal growth was lower in WLHIV than WNLHIV early in gestation but similar by the end of gestation, which is reassuring. Among WLHIV, fetal growth measures were generally similar across ART regimens evaluated.

Early neurodevelopment of HIV-exposed uninfected children in the era of antiretroviral therapy: a systematic review and meta-analysis

BACKGROUND

There are 15·4 million children who are HIV-exposed and uninfected worldwide. Early child development crucially influences later academic and socioeconomic factors. However, the neurodevelopmental outcomes of HIV-exposed uninfected (HEU) children in the era of maternal antiretroviral therapy (ART) remain unclear. We aimed to examine the effects of in-utero exposure to HIV and ART on child neurodevelopment.

METHODS

For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, Africa-Wide Information, PsycInfo, and Global Health databases from inception to May 27, 2020, for studies from the past two decades reporting neurodevelopment of HEU children aged 0-5 years compared with HIV-unexposed (HU) children (aim 1), and effects of different maternal ART regimens on neurodevelopment of HEU children (aim 2). We did narrative syntheses for both aims, and a random-effects meta-analysis of high-quality studies comparing HEU children and HU children, to obtain weighted pooled estimates of effect sizes. This study was registered with PROSPERO, CRD42018075910.

FINDINGS

We screened 35 527 records and included 45 articles from 31 studies. Overall, 12 (57%) of 21 studies comparing HEU children and HU children found worse neurodevelopment in HEU children in at least one domain. Study design and methodological quality were variable, with heterogeneity across populations. Meta-analysis included eight high-quality studies comparing 1856 HEU children with 3067 HU children at ages 12-24 months; among HEU children with available data, 1709 (99%) of 1732 were exposed to ART. HEU children had poorer expressive language (effect size -0·17 [95% CI -0·27 to -0·07], p=0·0013) and gross motor function (-0·13 [-0·20 to -0·07], p<0·0001) than HU children, but similar cognitive development (-0·06 [-0·19 to 0·06], p=0·34), receptive language development (-0·10 [-0·23 to 0·03], p=0·14), and fine motor skills (-0·05 [-0·15 to 0·06], p=0·36). Results suggested little or no evidence of an effect of specific maternal ART regimens on neurodevelopment; study heterogeneity prevented meta-analysis.

INTERPRETATION

HEU children are at risk of subtle impairments in expressive language and gross motor development by age 2 years. We found no consistent effect of maternal ART regimens analysed, although evidence was scarce. We highlight the need for large high-quality longitudinal studies to assess the neurodevelopmental trajectories of HEU children and to investigate underlying mechanisms to inform intervention strategies.

FUNDING

Wellcome Trust and Medical Research Council.

Early structural brain development in infants exposed to HIV and antiretroviral therapy in utero in a South African birth cohort

Introduction

There is a growing population of children who are HIV‐exposed and uninfected (HEU) with the successful expansion of antiretroviral therapy (ART) use in pregnancy. Children who are HEU are at risk of delayed neurodevelopment; however, there is limited research on early brain growth and maturation. We aimed to investigate the effects of in utero exposure to HIV/ART on brain structure of infants who are HEU compared to HIV‐unexposed (HU).

Methods

Magnetic resonance imaging using a T2‐weighted sequence was undertaken in a subgroup of infants aged 2–6 weeks enrolled in the Drakenstein Child Health Study birth cohort, South Africa, between 2012 and 2015. Mother–child pairs received antenatal and postnatal HIV testing and ART per local guidelines. We compared subcortical and total grey matter volumes between HEU and HU groups using multivariable linear regression adjusting for infant age, sex, intracranial volume and socio‐economic variables. We further assessed associations between brain volumes with maternal CD4 cell count and ART exposure.

Results

One hundred forty‐six infants (40 HEU; 106 HU) with high‐resolution images were included in this analysis (mean age 3 weeks; 50.7% male). All infants who were HEU were exposed to ART (88% maternal triple ART). Infants who were HEU had smaller caudate volumes bilaterally (5.4% reduction, p < 0.05) compared to HU infants. There were no group differences in other subcortical volumes (all p > 0.2). Total grey matter volume was also reduced in infants who were HEU (2.1% reduction, p < 0.05). Exploratory analyses showed that low maternal CD4 cell count (<350 cells/mm³) was associated with decreased infant grey matter volumes. There was no relationship between timing of ART exposure and grey matter volumes.

Conclusions

Lower caudate and total grey matter volumes were found in infants who were HEU compared to HU in the first weeks of life, and maternal immunosuppression was associated with reduced volumes. These findings suggest that antenatal HIV exposure may impact early structural brain development and improved antenatal HIV management may have the potential to optimize neurodevelopmental outcomes of children who are HEU.

Impact of in-utero antiretroviral drug exposure on expression of membrane-associated transporters in mouse placenta and fetal brain

OBJECTIVE

Although antiretroviral therapy (ART) during pregnancy is effective in limiting vertical HIV transmission, adverse outcomes persist amongst uninfected children exposed to antiretroviral drugs in utero. Membrane-associated drug transporters, metabolic enzymes, and tight junction proteins play important roles in adult antiretroviral drug disposition and toxicity; however, the fetal expression of these proteins in the context of ART, and their impact on in-utero antiretroviral drug distribution remain poorly understood. This study aimed to characterize the role of these proteins in modulating in-utero antiretroviral drug exposure.

METHODS

Pregnant mice were exposed to an ART regimen consisting of lamivudine, abacavir, atazanavir, and ritonavir, at clinically relevant doses. Fetal brain, liver, placenta amniotic fluid, and maternal plasma were collected on gestational day 18.5 and concentration of antiretroviral drugs in fetal tissues was measured by LC/MS/MS, whereas transporter expression was assessed by qPCR.

RESULTS

Abacavir and lamivudine were detected in fetal brain and amniotic fluid, whereas atazanavir and ritonavir were detected in amniotic fluid only. Robust mRNA expression of key transporters was observed in adult and fetal tissues, and sex differences were identified in the expression of Abcc1 and Slc29a1 in the placenta. Antiretroviral drug exposure was associated with a reduction in relative placental Abcg2, Abcc1, and Slc29a1 expression.

CONCLUSION

These findings identify a novel effect of fetal sex and antiretroviral drug treatment on the expression of placental transporters in a mouse model, and characterize the penetration of lamivudine and abacavir into fetal brain, uncovering a potential role of transporters in modulating fetal exposure to antiretroviral drugs.

Neurological development of children who are HIV-exposed and uninfected

Widespread use of antiretroviral drugs for pregnant/breastfeeding females with human immunodeficiency virus (HIV) has led to declining vertical transmission. Despite being HIV-uninfected, the increasing number of children who are HIV-exposed and uninfected (CHEU) often present with developmental alterations. We review seminal and recent evidence on the neurological development of CHEU and associations with early life HIV/antiretroviral exposure. Our conceptual model highlights the numerous exposures and universal risk factors for CHEU developmental disorders. Early studies suggest a significant association between HIV exposure and neurological abnormalities, varying according to the burden of HIV-specific exposures and other risk factors. More recent observations from the modern era are inconsistent, although some studies suggest specific antiretrovirals may adversely affect neurological development of CHEU. As the CHEU population continues to grow, alongside simultaneous increases in types and combinations of antiretrovirals used in pregnancy, long-term monitoring of CHEU is necessary for understanding the effects of HIV/antiretroviral exposure on CHEU developmental outcomes. What this paper adds Evidence on the neurological development of children who are human immunodeficiency virus (HIV)-exposed and uninfected (CHEU) is synthesized. Comparisons are made to children who are HIV-unexposed, across treatment eras and settings, and by antiretroviral drug regimens and drug classes. CHEU exposures are complex and include HIV-specific and universal risk factors which may affect development during the early years of life.

HIV in Neonates and Infants

Advances in perinatal HIV management have averted a significant number of infections in neonates and have made the possibility of elimination of mother-to-child transmission a reality; however, significant gaps in implementation of early testing programs as well as the expansion of therapeutic strategies to neonates are hindering prevention efforts and access to safer, more effective and easier to administer treatment. This article provides insights on the current state of perinatal HIV, recent advances, and future needs.

Differential effects of antiretroviral drug toxicity in male versus female children who are HIV-exposed but uninfected

: In recent years, widespread use of antiretroviral therapy (ART) during pregnancy has been increasingly effective in reducing risk of vertical transmission of HIV, with over 80% of pregnant women living with HIV now accessing ART, and a 41% reduction in new infections in children between 2010 and 2018. Despite these strides, the developmental toxicity of widely administered antiretroviral drugs (ARVs) remains poorly described and existing literature often fails to account for fetal and infant sex as a variable. Recent reports have identified associations between in-utero exposure to commonly used antiretroviral regimens and alteration in neurodevelopment, growth, and metabolism amongst children who are HIV-exposed but uninfected, with findings of sex differences in the prevalence and severity of ARV toxicity. These differences are potentially explained by variable exposure to ARV drugs in utero or exacerbation of existing sex-linked risk factors. Fetal ARV exposure is mediated by placental and fetal drug transporters and metabolic enzymes, which may contribute to the manifestation of sex differences. Existing evidence of sex differences in ARV toxicity in fetal development is concerning, and demands further research to guide optimal treatment options for maternal health and prevention of vertical HIV transmission.

In Utero HIV Exposure and the Early Nutritional Environment Influence Infant Neurodevelopment: Findings from an Evidenced Review and Meta-Analysis

The developing brain is especially vulnerable to infection and suboptimal nutrition during the pre- and early postnatal periods. Exposure to maternal human immunodeficiency virus (HIV) infection and antiretroviral therapies (ART) in utero and during breastfeeding can adversely influence infant (neuro) developmental trajectories. How early life nutrition may be optimised to improve neurodevelopmental outcomes for infants who are HIV-exposed has not been well characterised. We conducted an up-to-date evidence review and meta-analysis on the influence of HIV exposure in utero and during breastfeeding, and early life nutrition, on infant neurodevelopmental outcomes before age three. We report that exposure to maternal HIV infection may adversely influence expressive language development, in particular, and these effects may be detectable within the first three years of life. Further, while male infants may be especially vulnerable to HIV exposure, few studies overall reported sex-comparisons, and whether there are sex-dependent effects of HIV exposure on neurodevelopment remains a critical knowledge gap to fill. Lastly, early life nutrition interventions, including daily maternal multivitamin supplementation during the perinatal period, may improve neurodevelopmental outcomes for infants who are HIV-exposed. Our findings suggest that the early nutritional environment may be leveraged to improve early neurodevelopmental trajectories in infants who have been exposed to HIV in utero. A clear understanding of how this environment should be optimised is key for developing targeted nutrition interventions during critical developmental periods in order to mitigate adverse outcomes later in life and should be a priority of future research.

Pediatric Antiretroviral Therapy

Human immunodeficiency virus (HIV) is one of the most serious pediatric infectious diseases, affecting around 3 million children and adolescents worldwide. Lifelong antiretroviral treatment (ART) provides multiple benefits including sustained virologic suppression, restoration and preservation of immune function, decreased morbidity and mortality, and improved quality of life. However, access to ART, particularly among neonates and young infants, continues to be challenging due to limited number of suitable formulations and limited access to pediatric ARV drug. Moreover, children and adolescents living with HIV may experience long-term HIV- and ART-associated comorbidities including cardiovascular, renal, neurological, and metabolic complications. We provide an overview of currently available formulations, dosing, and safety considerations for pediatric antiretroviral drugs by drug classes and according to the three age groups including neonates, children, and adolescents.

Safety of in-utero antiretroviral exposure: neurologic outcomes in children who are HIV-exposed but uninfected

OBJECTIVE

To evaluate whether there is an increased risk of neurologic diagnoses in children who are HIV-exposed but uninfected (CHEU) exposed in utero to specific antiretroviral medications.

DESIGN

Prospective cohort study of CHEU enrolled from 2007 to 2017.

METHODS

We evaluated children for neurologic case status, including microcephaly, febrile seizures, seizure disorders, ophthalmologic disorders, and other neurologic disorders. Adjusted relative risks (aRRs) were estimated for the association between in-utero antiretroviral exposure and neurologic case using log-binomial regression, accounting for potential confounders. Sensitivity analyses were conducted to evaluate robustness of findings.

RESULTS

Among 3747 eligible CHEU, 231 (6.2%) met neurologic case criteria (95% CI 5.4--7%). Most eligible children (86%) were exposed in utero to combination antiretroviral regimens. In adjusted models, children exposed to efavirenz at any time during pregnancy had higher risk of neurologic case status (aRR = 1.53, 95% CI 0.94--2.51). This association was stronger when comparing efavirenz exposure at conception to no exposure during pregnancy (aRR = 1.92, 95% CI 1.09--3.36) and considering follow-up and case diagnosis only through age 2 (aRR = 2.14, 95% CI 1.11--4.12). Children exposed to didanosine at conception and during the first trimester had increased risk of neurologic case status (aRR = 2.28, 95% CI 1.07--4.87 and aRR = 2.02, 95% CI 1.01--4.04, respectively), compared with didanosine-unexposed children. Children with dolutegravir exposure had some suggestion of increased risk of neurologic case (aRR = 2.43, 95% CI 0.75--7.84), which was observed consistently across several sensitivity analyses.

CONCLUSION

Efavirenz and didanosine exposure during pregnancy were associated with higher risk of neurologic abnormalities in CHEU, and dolutegravir exposure showed some suggestive associations, which warrant further monitoring.

Association of maternal antiretroviral use with microcephaly in children who are HIV-exposed but uninfected (SMARTT): a prospective cohort study

BACKGROUND

Perinatal HIV transmission has substantially decreased with combination antiretroviral regimens, but complications in children who are HIV-exposed but uninfected, such as microcephaly, warrant ongoing surveillance. We aimed to evaluate whether individual in utero antiretroviral exposures were associated with increased risk of microcephaly based on long-term follow-up of infants and children who are HIV-exposed but uninfected.

METHODS

We evaluated children aged younger than 18 years who were HIV-exposed but uninfected with at least one head circumference measurement while enrolled in the Surveillance Monitoring for ART Toxicities (SMARTT) study at 22 clinical sites in the USA, including Puerto Rico. This prospective cohort study was done by the Pediatric HIV/AIDS Cohort Study network. Microcephaly was defined as having a head circumference Z score <-2 according to the 2000 US Centers for Disease Control and Prevention growth charts for children 6-36 months old and according to Nellhaus standards (head circumference <2nd percentile) after 36 months (SMARTT criteria); an alternate definition for microcephaly was based on applying Nellhaus standards across all ages (Nellhaus criteria). Modified Poisson regression models were fit to obtain relative risks (RRs) for associations between in utero antiretroviral exposure and microcephaly status, adjusted for potential confounders. Neurodevelopmental functioning was compared in children who are HIV-exposed but uninfected with or without microcephaly.

FINDINGS

Between March 21, 2007, and Aug 1, 2017, 3055 participants enrolled in SMARTT had at least one head circumference measurement. The cumulative incidence of microcephaly over a median of 5·1 years of follow-up (IQR 3·0-7·2) was 159 (5·2%, 95% CI 4·4-6·1) by Nellhaus criteria and 70 (2·3%, 1·8-2·9) by SMARTT criteria. In adjusted models, in utero exposure to efavirenz (4·7% exposed) was associated with increased risk of microcephaly by both Nellhaus standards (adjusted RR 2·02, 95% CI 1·16-3·51) and SMARTT criteria (2·56, 1·22-5·37). These associations were more pronounced in children exposed to combination regimens of efavirenz that included zidovudine plus lamivudine than those including tenofovir plus emtricitabine. Protective associations were observed for darunavir exposure (adjusted RR 0·50, 95% CI 0·24-1·00). Children who are HIV-exposed but uninfected with microcephaly had lower mean scores on neurodevelopmental assessments at age 1 and 5 years and a higher prevalence of neurodevelopmental impairment than those without microcephaly.

INTERPRETATION

These findings support consideration of alternatives to efavirenz as part of first-line antiretroviral therapy for pregnant women.

FUNDING

Eunice Kennedy Shriver National Institute of Child Health and Human Development.

Neurodevelopmental outcomes and in-utero antiretroviral exposure in HIV-exposed uninfected children

OBJECTIVES

To assess and compare neurodevelopmental disorders in HIV-exposed uninfected (HEU) and HIV-unexposed uninfected (HUU) children in British Columbia, Canada. To determine associations between these outcomes and in-utero exposure to antiretroviral drugs.

DESIGN

Retrospective controlled cohort study.

METHODS

Data were collected on 446 HEU children and 1323 HUU children (matched ∼1 : 3 for age, sex, and geocode) born between 1990 and 2012. Multivariable logistic regressions determined odds ratios of neurodevelopmental disorder diagnoses.

RESULTS

HEUs had three times higher odds of being born preterm (P < 0.0001), and a more than two-fold increase in odds for autism, disturbance of emotions, hyperkinetic syndrome, and developmental delay compared with matched HUUs (P < 0.02) in unadjusted analysis. This association was reduced [adjusted neurodevelopmental disorder odds ratio (AOR) = 1.67; 95% confidence interval: 1.12-2.48; P = 0.011] after adjusting for maternal substance use and/or smoking (children born after April 2000). Regardless of antiretroviral exposure type (i.e. none, treatment with one or multiple drug classes), HEUs had higher odds of any neurodevelopmental disorders compared with matched HUUs; however, there was no evidence suggesting any specific classes of antiretroviral drugs or exposure durations increased their likelihood of neurodevelopmental disorders.

CONCLUSION

The results suggest no adverse associations between antiretroviral drugs and neurodevelopmental disorders within antiretroviral-exposed HEU children in our cohort. Prevalence of neurodevelopmental disorders is higher in HEUs; however, maternal substance use plays a role, as could other environmental factors not captured. These findings highlight a need for holistic support for pregnant women as well as careful developmental monitoring of HEUs past infancy, and access to early interventions, particularly among those born preterm and those exposed to addictive substances.

Propelling the Pediatric HIV Therapeutic Agenda With Science, Innovation, and Collaboration

BACKGROUND

A number of well-described obstacles to the pediatric therapeutic agenda have resulted in substantial delays in the introduction of new medications, formulations, strategies, and approaches to treat infants, children, and adolescents living with HIV.

SETTING

Global landscape.

METHODS

The authors will provide a summary of current and emerging initiatives to accelerate the pediatric therapeutic agenda including illustrative case studies of innovations and scientific discovery in diagnosis and treatment of very young children with HIV infection.

RESULTS

The challenges posed by rapid physiologic and developmental changes that characterize the trajectory of childhood as well as the complex regulatory and fiscal milieu of HIV therapeutics have hampered pediatric HIV therapeutic research. Recent efforts to accelerate this agenda include prioritizing agents and formulations, defining dosing by weight bands, applying innovative study designs, synergizing work across research networks to achieve common goals, and the establishment of a global prioritized research agenda. A case study of initiatives to diagnose and effectively treat newborns and infants will illustrate the critical role of basic science research and novel approaches to study design and implementation that are informing global efforts to end AIDS.

CONCLUSIONS

A pediatric therapeutic agenda informed by basic science and achieved through innovation and global cooperation is essential to achieve an AIDS-free generation.

Neurodevelopmental outcome of HIV-exposed but uninfected infants in the Mother and Infants Health Study, Cape Town, South Africa

OBJECTIVES

To compare neurodevelopmental outcomes of HIV-exposed uninfected (HEU) and HIV-unexposed uninfected (HUU) infants in a peri-urban South African population. HEU infants living in Africa face unique biological and environmental risks, but uncertainty remains regarding their neurodevelopmental outcome. This is partly due to lack of well-matched HUU comparison groups needed to adjust for confounding factors.

METHODS

This was a prospective cohort study of infants enrolled at birth from a low-risk midwife obstetric facility. At 12 months of age, HEU and HUU infant growth and neurodevelopmental outcomes were compared. Growth was evaluated as WHO weight-for-age, length-for-age, weight-for-length and head-circumference-for-age Z-scores. Neurodevelopmental outcomes were evaluated using the Bayley scales of Infant Development III (BSID) and Alarm Distress Baby Scale (ADBB).

RESULTS

Fifty-eight HEU and 38 HUU infants were evaluated at 11-14 months of age. Performance on the BSID did not differ in any of the domains between HEU and HUU infants. The cognitive, language and motor scores were within the average range (US standardised norms). Seven (12%) HEU and 1 (2.6%) HUU infant showed social withdrawal on the ADBB (P = 0.10), while 15 (26%) HEU and 4 (11%) HUU infants showed decreased vocalisation (P = 0.06). There were no growth differences. Three HEU and one HUU infant had minor neurological signs, while eight HEU and two HUU infants had macrocephaly.

CONCLUSIONS

Although findings on the early neurodevelopmental outcome of HEU infants are reassuring, minor differences in vocalisation and on neurological examination indicate a need for reassessment at a later age.

Longitudinal development of cognitive, visuomotor and adaptive behavior skills in HIV uninfected children, aged 3-5 years of age, exposed pre- and perinatally to anti-retroviral medications

Little is known about the neurodevelopmental outcomes of children older than 3 years of age born to HIV infected mother but who are HIV-uninfected (HEU), and who have been exposed in utero and early in life to HIV and to antiretroviral medications (ARVs). We conducted a longitudinal study of cognitive, visuomotor and adaptive function of HEU children, who were assessed at two ages, 3.5 and 5.5 years. Sixty-four children (33 female) were assessed. In comparison with population norms for their age, at 3.5 years of age they had scores significantly below age expectations on aspects of adaptive behavior, but at age 5.5 years, their scores did not significantly diverge from the population norms on any of the measures. Verbal intelligence was lower at age 5.5 than at age 3.5 years, although there were also improvements in some features of adaptive behavior. Exposure to PI-based ARVs (compared to NNRTIs) was associated with higher Performance IQ, visuomotor and communication scores at age 5.5 years. Birth, early growth, and sociodemographic variables were predictive of outcomes. This study is important in tracking the trajectory of neurocognitive development across the pre-school and early school age years. The findings suggest that the full impact of early ARV exposure may not be evident until a considerable period of development has occurred. The results raise the possibility of negative effects of early ARV exposure on neurodevelopment that emerge over time, and reiterate the importance of sociodemographic and early health variables for optimal development.