Associations of Memory and Executive Functioning With Academic and Adaptive Functioning Among Youth With Perinatal HIV Exposure and/or Infection

Perinatal exposure to atazanavir-based antiretroviral regimens in a mouse model leads to differential long-term motor and cognitive deficits dependent on the NRTI backbone

Background

Combination antiretroviral therapy (ART) use in pregnancy has been pivotal in improving maternal health and reducing perinatal HIV transmission. However, children born HIV-exposed uninfected fall behind their unexposed peers in several areas including neurodevelopment. The contribution of in utero ART exposure to these deficits is not clear. Here we present our findings of neurocognitive outcomes in adult mice exposed in utero to ART.

Methods

Dams were treated with a combination of ritonavir-boosted atazanavir with either abacavir plus lamivudine (ABC/3TC + ATV/r) or tenofovir disoproxil fumarate plus emtricitabine (TDF/FTC + ATV/r), or water as a control, administered daily from day of plug detection to birth. Offspring underwent a battery of behavioral tests that investigated motor performance and cognition starting at 6-weeks of age and ending at 8 months. Changes in brain structure were assessed using magnetic resonance imaging and immunohistochemistry. Expression of genes involved in neural circuitry and synaptic transmission were assessed in the hippocampus, a region strongly associated with memory formation, using qPCR.

Findings

Pups exposed to TDF/FTC + ATV/r showed increased motor activity and exploratory drive, and deficits in hippocampal-dependent working memory and social interaction, while pups exposed to ABC/3TC + ATV/r showed increased grooming, and deficits in working memory and social interaction. Significant volumetric reductions in the brain were seen only in the ABC/3TC + ATV/r group and were associated with reduced neuronal counts in the hippocampus. Altered neurotransmitter receptor mRNA expression as well as changes in expression of the neurotrophic factor BDNF and its receptors were observed in both ART-exposed groups in a sex-dependent manner.

Interpretation

In our model, in utero ART exposure had long-term effects on brain development and cognitive and motor outcomes in adulthood. Our data show that neurological outcomes can be influenced by the type of nucleoside reverse transcriptase inhibitor backbone of the regimen and not just the base drug, and display sex differences.

Adaptation and construct validity evaluation of a tablet-based, short neuropsychological test battery for use with adolescents and young adults living with HIV in Thailand

OBJECTIVE

Deficits in neurocognitive functioning are common among adolescents and young adults (AYA) with perinatally acquired HIV (PHIV). Limitations of traditional neuropsychological tests hinder assessment of neurocognition in low- and middle-income countries where most AYA with PHIV reside. Computerized testing could make assessment of neurocognition more accessible in these countries. This study examined a culturally modified NeuroScreen, a tablet-based neurocognitive testing app, for use in Thailand. Construct validity was examined among Thai AYA (13-23 years) with and without PHIV.

METHOD

NeuroScreen underwent adaptation including language, content, and usability review by Thai psychologists, AYA, and clinical staff. One hundred Thai AYA (50 PHIV; 50 HIV-uninfected, matched controls) were administered the adapted NeuroScreen and a battery of traditional paper-and-pencil neuropsychological tests. Correlations, mean differences, and proportions with impaired performance were examined across NeuroScreen and the traditional tests.

RESULTS

The Thai version of NeuroScreen was deemed understandable and culturally appropriate. A large correlation (.82) between overall performance on the NeuroScreen and traditional batteries was observed. Small-to-large correlations were found between conceptually similar NeuroScreen and traditional tests of processing speed, working memory, motor speed, and executive functioning. Mean test performance differences between AYA with PHIV and controls were similar between test batteries. Both sets of tests identified similar rates of impaired participants.

CONCLUSIONS

Results provide support for the acceptability and construct validity of the Thai NeuroScreen tests to assess neurocognition in Thai AYA with PHIV. An easy-to-use tool to assess neurocognition can help Thai providers provide better care for AYA with PHIV. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Ageing with HIV: a longitudinal study of markers of resilience in young adults with perinatal exposure to HIV, with or without perinatally acquired HIV

INTRODUCTION

Medical challenges, including perinatally acquired HIV (PHIV), can be considered adversity with the potential to compromise individuals' ability to meet societal expectations across the lifespan. Studies suggest that resilience, defined as positive adaptation in the context of adversity, helps individuals overcome challenges and improve their quality of life. Few longitudinal studies have examined resilience in young adults with perinatally acquired HIV (YAPHIV) or perinatal HIV exposure, uninfected (YAPHEU). We examined three young adult milestones, which can affect the life-long quality of life, as markers of resilience: high school graduation, postsecondary education and current employment.

METHODS

Analyses included YAPHIV and YAPHEU, ages 19-27 years, followed in longitudinal cohort studies: Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol (AMP) (7-17 years) and AMP Up (≥18 years). Factors known to influence the attainment of milestones (outcomes) were examined: executive function, cognitive efficiency (working memory and processing speed), behavioural/social-emotional functioning, parent/caregiver mental/physical health and cumulative risk. HIV disease markers for YAPHIV were examined. The most recent AMP assessment was used for each factor; outcomes were measured at AMP Up 1-year follow-up. Separate robust Poisson regression models were used to assess associations of each factor with each outcome; PHIV status was explored as an effect modifier of each association.

RESULTS

Participants (N = 315; YAPHIV = 228): 58% female, 67% Black and 27% Hispanic. Compared to YAPHEU, YAPHIV were older and from families with higher median income and fewer symptoms of parent/caregiver mental health/substance use disorders. Proportions of YAPHIV and YAPHEU, respectively, who achieved each milestone were comparable: 82% versus 78% for high school graduation (p = 0.49), 45% versus 51% for postsecondary education (p = 0.35) and 48% versus 54% for current employment (p = 0.32). Higher cognitive efficiency was positively associated with postsecondary education and current employment. Higher executive function, age-appropriate behavioural/social-emotional functioning and lower cumulative risk were associated with academic milestones. Among YAPHIV, positive associations were: higher current CD4 with postsecondary education and lower nadir CD4 with current employment. PHIV status did not modify any association.

CONCLUSIONS

YAPHIV and YAPHEU demonstrated resilience, attaining at least one young adult milestone. Cognitive, behavioural and social resources to support resilience in childhood and adolescence may provide the foundation for continued achievement throughout adulthood.

Central Nervous System Impact of Perinatally Acquired HIV in Adolescents and Adults: an Update

Purpose of Review

Perinatally acquired HIV infection (PHIV) can confer neurodevelopmental risk. As children with PHIV increasingly survive through adolescence and into adulthood, understanding its long-term central nervous system (CNS) impacts is critical for maximizing adult outcomes and quality of life.

Recent Findings

Recently published neurocognitive and neuroimaging findings show impacts on the CNS associated with early HIV disease progression that endure into adolescence and young adulthood. Although developmental trajectories in adolescence largely appear stable, further research on maturational processes is indicated.

Summary

Although early antiretroviral therapy in infancy appears to be protective, it is not universally available and current youth largely developed without its benefit. The neurocognitive effects of HIV and the multiple other risks to neurodevelopment experienced by youth with PHIV call for further longitudinal research and a multifaceted approach to prevention and intervention.

Learning and memory function in young people with and without perinatal HIV in England

Learning and memory are important for successful education and career progression. We assess these functions in young people (YP) with perinatal HIV (PHIV) (with or without a previous AIDS-defining illness) and a comparable group of HIV-negative YP. 234 PHIV and 68 HIV-negative YP completed 9 tests; 5 National Institutes of Health (NIH) Toolbox tests (2 executive function, 1 speed of information processing, 2 memory); 2 Hopkins Verbal Learning Test Revised (HVLT-R) (learning (L), delayed recall (R)), and 2 verbal application measures. Z-scores for each test were calculated using normative data and averaged by domain where appropriate. The effect of predictors on test scores in the three domains with the lowest z-scores were analysed using linear regression. 139(59%) and 48(71%) PHIV and HIV-negative YP were female, 202(86%) and 52(76%) Black, and median age was 19 [17, 21] and 18 [16, 21] years respectively. 55(24%) PHIV had a previous Center for Disease Control and Prevention (CDC) class C AIDS-defining diagnosis (PHIV/C). For HVLT-R, there was a trend towards PHIV/C YP having the lowest mean z-scores (L -1.5 (95% CI -1.8,-1.2), R -1.7 (-2.0,-1.4)) followed by PHIV without a CDC C diagnosis (L -1.3 (-1.4,-1.1), R -1.4 (-1.5,-1.2)) and then the HIV-negative group (L -1.0 (-1.3,-0.7), R -1.1 (-1.3,-0.8)); all were greater than 1 SD below the reference mean. The same trend was seen for verbal application measures; however, z-scores were within 1 SD below the reference mean. NIH Toolbox tests were similar for all groups. In multivariable analyses PHIV/C and Black ethnicity predicted lower HVLT-R scores. Black ethnicity also predicted lower executive function scores, however each year increase in age predicted higher scores. In conclusion, cognitive performance in verbal learning and recall fell below population normative scores, and was more pronounced in PHIV/C, supporting wider findings that earlier antiretroviral therapy initiation, before the occurrence of AIDS-defining conditions, may protect aspects of cognitive development.

Mental health and adaptive functioning among school-aged children living with HIV in Zambia

BACKGROUND

The number of children living with HIV (CLWHIV) has been increasing, reflected by lower mortality. However, this change is coupled with higher rates of morbidity, where CLWHIV face considerable challenges, including neurocognitive delays and mental health and behavioral functioning challenges. Despite Sub-Sahara accounting for the highest number of CLWHIV, there is still limited research on the effects of HIV on child mental health and adaptive functioning.

METHOD

Mental health and adaptive functioning were assessed in 120 children. The sample included 62 CLWHIV and 58 demographically-matched HIV-uninfected children aged 6-12 years. Mental health was assessed using the Connors, while adaptive functioning was assessed using the Vineland Adaptive Behavioral Scale (VABS).

RESULTS

Scores obtained were within average ranges for mental health (T-score 40-59) and adaptive functioning standard scores (70-115). However, CLWHIV had significantly higher mental health problems than uninfected children in executive functioning and aggressiveness (p < 0.05). CLWHIV had lower adaptive functioning scores on the VABS Communication domain although these differences were not significant. In the Daily Living Skills domain, CLWHIV had significantly higher scores than the HIV-uninfected children (p < 0.05). There were no significant differences in the Socialization subdomain. Furthermore, CLWHIV had significantly higher scores on the Maladaptive Behavior scales of the VABS' internalizing and externalizing subdomains.

CONCLUSION

Challenges to mental health and adaptive functioning are still pervasive among CLWHIV. These findings support the need to develop support mechanisms for CLWHIV to help address mental health and adaptive functioning problems, especially as they progress into adolescence.

Reduced neuronal population in the dorsolateral prefrontal cortex in infant macaques infected with simian immunodeficiency virus (SIV)

Pediatric HIV infection remains a global health crisis with an estimated 150,000 new mother-to-child (MTCT) infections each year. Antiretroviral therapy (ART) has improved childhood survival, but only an estimated 53% of children worldwide have access to treatment. Adding to the health crisis is the neurological impact of HIV on the developing brain, in particular cognitive and executive function, which persists even when ART is available. Imaging studies suggest structural, connectivity, and functional alterations in perinatally HIV-infected youth. However, the paucity of histological data limits our ability to identify specific cortical regions that may underlie the clinical manifestations. Utilizing the pediatric simian immunodeficiency virus (SIV) infection model in infant macaques, we have previously shown that early-life SIV infection depletes the neuronal population in the hippocampus. Here, we expand on these previous studies to investigate the dorsolateral prefrontal cortex (dlPFC). A total of 11 ART-naïve infant rhesus macaques (Macaca mulatta) from previous studies were retrospectively analyzed. Infant macaques were either intravenously (IV) inoculated with highly virulent SIVmac251 at ~1 week of age and monitored for 6-10 weeks or orally challenged with SIVmac251 from week 9 of age onwards with a monitoring period of 10-23 weeks post-infection (19-34 weeks of age), and SIV-uninfected controls were euthanized at 16-17 weeks of age. Both SIV-infected groups show a significant loss of neurons along with evidence of ongoing neuronal death. Oral- and IV-infected animals showed a similar neuronal loss which was negatively correlated to chronic viremia levels as assessed by an area under the curve (AUC) analysis. The loss of dlPFC neurons may contribute to the rapid neurocognitive decline associated with pediatric HIV infection.

Neuropsychological and Psychosocial Functioning of Children with Perinatal HIV-Infection in The Netherlands

Advances in antiretroviral treatment improved the life expectancy of perinatally HIV-infected children. However, growing up with HIV provides challenges in daily functioning. This cross-sectional cohort study investigated the neuropsychological and psychosocial functioning of a group of perinatally HIV-infected children in the Netherlands and compared their outcomes with Dutch normative data and outcomes of a control group of uninfected siblings. The children’s functioning was assessed with internationally well-known and standardized questionnaires, using a multi-informant approach, including the perspectives of caregivers, teachers, and school-aged children. In addition, we explored the associations of socio-demographic and medical characteristics of the HIV-infected children with their neuropsychological and psychosocial functioning. Caregivers reported compromised functioning when compared to Dutch normative data for HIV-infected children in the areas of attention, sensory processing, social-emotional functioning, and health-related quality of life. Teachers reported in addition compromised executive functioning for HIV-infected children. A comparison with siblings revealed differences in executive functioning, problems with peers, and general health. The concurrent resemblance between HIV-infected children and siblings regarding problems in other domains implies that social and contextual factors may be of influence. A family-focused approach with special attention to the child’s socio-environmental context and additional attention for siblings is recommended.

School functioning of children with perinatal HIV-infection in high-income countries: A systematic review

Introduction

Since the introduction of combination antiretroviral therapy, human immunodeficiency virus (HIV) infection is a manageable chronic disease. However, school-age children (4–18 years) living with HIV could still experience problems with functioning at school, due to the impact of the virus itself, medication, comorbidities and social stigma. School functioning covers academic achievement, school attendance, and social relationships and is of utmost importance to optimize normal participation.

Methods

To gain insight in school functioning problems of perinatally HIV-infected children, we performed a systematic review of the literature in multiple databases from January 1997 up to February 2019. Studies were included if they described outcomes of school functioning of school-age children perinatally infected with HIV, in high-income countries. Meta-analyses were performed for sufficiently comparable studies.

Results and discussion

Results from 32 studies show that HIV-infected children experience more problems in various areas of school functioning in comparison with national norms, matched healthy controls, siblings and HIV-exposed uninfected (HEU) children. The most pronounced differences concerned the usage of special educational services, general learning problems, and mathematics and reading performance scores. Comparisons with both national norms and siblings/HEU children show that the differences between HIV-infected children and siblings/HEU children were less pronounced. Moreover, siblings/HEU children also reported significantly worse outcomes compared to national norms. This suggests that problems in school functioning cannot be solely attributed to the HIV-infection, but that multiple socio-economic and cultural factors may play a role herein.

Conclusion

Perinatally HIV-infected children seem vulnerable to problems in various areas of school functioning. Therefore, monitoring of school functioning should be an important aspect in the care for these children. A family-focused approach with special attention to a child’s socio-environmental context and additional attention for siblings and HEU children, is therefore recommended.

The relationship between executive function, risky behaviour and HIV in young women from the HPTN 068 study in rural South Africa

Executive function (EF) may predict sexual risk-taking and HIV risk in young women in rural South Africa. We tested associations between EF and seven risky behavioural outcomes: binge drinking, illicit substance use, unprotected vaginal sex, concurrent sexual relationships, transactional sex, herpes simplex virus type 2 (HSV-2) infection, and HIV infection. We compared EF in young women with HIV to matched controls. 1080 young women underwent cognitive assessments. Better verbal short-term memory was associated with a lower risk of HSV-2 (OR 0.77; 95% CI 0.69, 0.86; p < 0.001). Uncorrected trends (p < 0.05) were better verbal working memory being associated with a lower risk of concurrency, better planning with a lower risk of illicit drug use, and better affective inhibition with a lower risk of transactional sex. 78 participants with sexually acquired HIV were matched with 153 HIV-negative controls and had poorer verbal working memory than controls (Hedge's g = -0.38; 95% CI -0.66, -0.10; p = 0.0076), but this was non-significant after adjustment. EF's contribution to young women's risky behaviour in this context does not hold when stringent statistical corrections are applied, with only verbal short term memory reaching statistical significance as predictor. Replication in other samples is recommended.

Executive function in HIV-affected children and adolescents: a systematic review and meta-analyses

This review aimed to determine: whether EF is affected in children and adolescents (2-24-years-old) with perinatal HIV infection, perinatal HIV exposure without infection, and behaviourally acquired HIV. A systematic review (PROSPERO number: CRD42017067813) was conducted using 11 electronic databases (01.01.1981-09.07.2019) and 8 conference websites. Primary quantitative studies with EF scores on cognitive tasks and/or behavioural report measures were included. Meta-analyses were performed by EF subtype and subpopulations compared. 1789 records were found. Sixty-one studies were included in the narrative synthesis; 32 (N = 7884 participants) were included in meta-analyses. There was a distinct pattern of reduced EF in those with perinatal HIV infection on antiretroviral therapy compared to controls: pooled effect sizes were largest for verbal and visuospatial working memory, with smaller effects on planning, inhibitory control and set-shifting. Data were limited for other HIV-affected subpopulations. Perinatal HIV infection is associated with reduced EF with varying effect sizes for the different EF subtypes.

Youth perinatal HIV-associated neurocognitive disorders: association with functional impairment

HIV-associated functional impairment may cause cognitive impairment secondary to the viral infection, hence, associations between cognitive impairment and functional impairment in youth living with HIV are important to assess. We sought to determine whether cognitive impairment is associated with functional impairment and if it carries higher risk for also having functional impairment. We collected parent-rated information regarding youth functional impairment on four different measures and administered a cognitive battery to youth to determine cognitive impairment, 203 HIV-infected youth and 44 HIV-uninfected controls. Degree of cognitive impairment correlated strongly with decreased function: CBCL, r = -.17, p = .01; VABS2, r = -.28, p < .001; repeated-grades, r = .26, p < .001. Presence of cognitive impairment was associated with increased risk of functional impairment: 3.47 (CIS); 1.71 (CBCL); 2.17 (VABS2); 2.97 (repeated-grades). Repeated-grades strongly associated with cognitive impairment and functional impairment. We found strong associations between HIV-infected youth functional impairment on CBCL, VABS2 and repeated-grades with degree of cognitive impairment; and that when cognitive impairment was present youth had higher risk of experiencing functional impairment as well. Asking whether youth have repeated a grade at school could be a helpful screening question for assessing potential functional impairment and provide clinicians with an indication as to whether a further in-depth assessment is required.

Early academic achievement of HIV-exposed uninfected children compared to HIV-unexposed uninfected children at 5 years of age

HIV-exposed uninfected (HEU) children may be at-risk for poorer academic achievement compared to HIV-unexposed uninfected (HUU) children due to in utero and perinatal exposure to HIV and/or anti-retroviral (ARV) medication. Understanding the risk factors for academic underachievement is important for implementing timely intervention and academic supports. HEU (N = 110, mean (SD) age 5.59 (0.22) years) and HUU (N = 43, mean (SD) age 5.73 (0.64) years) children completed assessments of general intelligence (WPPSI-III) and academic achievement (WRAT-4). Parent interviews and medical record reviews were used to obtain sociodemographic and maternal health data. HUU children scored significantly higher than HEU children on single word reading (p = 0.006), math calculation skills (p = 0.003), Verbal IQ, Performance IQ, Full Scale IQ, and Processing Speed (all WPPSI-III measures p < 0.001). Verbal IQ at 3-4 years predicted academic achievement at 5-6 years of age, yet sociodemographic and medical factors did not. These findings demonstrate that HEU children obtained significantly lower scores of intellectual, reading, and math abilities during early childhood. Addressing these early gaps before HEU children enter primary school will be critical for optimizing their learning and academic potential.

Neurocognitive Development in Perinatally Human Immunodeficiency Virus-infected Adolescents on Long-term Treatment, Compared to Healthy Matched Controls: A Longitudinal Study

BACKGROUND

A cross-sectional analysis of the Neurological, cOgnitive and VIsual performance in hiv-infected Children cohort showed significant cognitive impairment in combination antiretroviral therapy (cART)-treated, perinatally human immunodeficiency virus (HIV)-infected adolescents (PHIV+) compared to age-, sex-, ethnicity- and socioeconomic status (SES)-matched HIV-negative controls (HIV-). In this longitudinal study, we compared cognitive development in the same adolescents over time.

METHODS

We repeated the standardized cognitive test battery after a mean of 4.6 years (standard deviation 0.3). In participants who completed both assessments, we compared cognitive trajectories between groups in the domains of intelligence quotient (IQ), processing speed, working memory, executive functioning, learning ability, and visual-motor function, using linear mixed models. We explored associations with disease- and treatment-related factors and used multivariate normative comparison (MNC) to determine the prevalence of cognitive impairment.

RESULTS

There were 21 PHIV+ and 23 HIV- participants that completed 2 assessments and were similar concerning age, sex, ethnicity, and SES. Compared to HIV- participants, in PHIV+ participants the IQ score increased significantly more over time (group*time 6.01, 95% confidence interval [CI] 1.5-10.50; P = .012), whereas executive functioning decreased significantly more (group*time -1.43 z score, 95% CI -2.12 to -0.75; P < .001), resulting in the disappearance and appearance of significant differences. Processing speed, working memory, learning ability, and visual-motor function trajectories were not statistically different between groups. Univariately, those who had started cART at an older age deviated more in executive functioning (-0.13 z score, 95% CI -0.24 to -0.02; P = .043). The prevalence of cognitive impairments by MNC was similar in both groups, at both time points.

CONCLUSIONS

The cART-treated PHIV+ adolescents appeared to have similar global cognitive development, compared to their healthy peers. Executive functioning trajectory appears to deviate, potentially explained by earlier brain damage.

Neurodevelopment of HIV-Exposed Uninfected Infants Born to Women With Perinatally Acquired HIV in the United States

BACKGROUND

Lifelong HIV and antiretroviral therapy may confer neurodevelopmental risk on the children of women with perinatally acquired HIV infection (PHIV).

SETTING

We analyzed data from HIV-exposed uninfected (HEU) infants born to women with PHIV vs. non-perinatally acquired HIV (NPHIV) enrolled in the Surveillance Monitoring for Antiretroviral Therapy Toxicities (SMARTT) study.

METHODS

Using the Bayley Scales of Infant and Toddler Development, third Ed. (Bayley-III), we compared neurodevelopmental outcomes at the age of 1 year in HEU infants born to women with PHIV vs. NPHIV. Those with valid Bayley-III data at the age of 1 year and a mother born after 1982 were included. Cognitive, language, and motor domains were assessed as continuous composite scores. Linear mixed effects models were fit to estimate the mean difference in Bayley-III scores between groups, adjusting for confounders.

RESULTS

Five hundred fifty women with HIV gave birth to 678 HEU children (125 and 553 born to women with PHIV and NPHIV, respectively). Mean scores for each of the Bayley-III domains were not significantly different between infants born to women with PHIV vs. NPHIV in unadjusted models. After adjustment, infants of women with PHIV had lower language (91.9 vs. 94.8, P = 0.05) and motor (93.7 vs. 96.8, P = 0.03) composite scores, but no differences in cognitive composite scores.

CONCLUSIONS

Cognitive domain outcomes of infants born to women with PHIV vs. NPHIV are reassuring. Differences in early language and motor functioning, while of modest clinical significance, highlight the importance of long-term monitoring of neurodevelopment in children of women with PHIV.

Cognitive and Language Development at Age 4-6 Years in Children HIV-Exposed But Uninfected Compared to Those HIV-Unexposed and to Children Living With HIV

Perinatal HIV infection is associated with delayed neurocognitive development, but less is known about children perinatally HIV-exposed but uninfected (CHEU). We compared cognitive and language outcomes in 4-6-year old CHEU versus children HIV-unexposed and uninfected (CHUU) and children living with HIV (CLHIV). We enrolled 1,581 children (77% of the child population) in five communities in KwaZulu-Natal, South Africa. Children completed: Grover-Counter Scale of cognitive development, sub-scales of the Kaufman Assessment Battery for Children, Reynell Developmental Language Scales. HIV status of children and primary caregivers was determined by repeated rapid tests or report of prior testing. We conducted a cross-sectional multivariable linear regression on 922 dyads with complete data (257 CHEU, 627 CHUU, 38 CLHIV). On all outcome measures, CHEU and CHUU groups had comparable scores; CLHIV scored significantly lower. Emerging global progress toward the elimination of vertical HIV transmission may not only reduce mortality, but also positively impact child development.

Growth and Neurodevelopment of HIV-Exposed Uninfected Children: a Conceptual Framework

Purpose of Review

The population of HIV-exposed uninfected (HEU) children is expanding rapidly, and over one million HEU infants are born each year globally. Several recent studies have reported that HEU children, particularly in low- and middle-income countries, are at risk of poor outcomes, including impaired growth and neurodevelopment. However, the reasons for poor clinical outcomes amongst HEU children remain unclear.

Recent Findings

We summarise the findings from recent large studies that have characterised growth and neurodevelopment in HEU children, identified risk factors and explored underlying mechanistic pathways. We propose a conceptual framework to explain how exposure to HIV and antiretroviral therapy (ART) may lead to adverse growth and neurodevelopment in uninfected children, and review the available evidence and research gaps.

Summary

We propose that HEU children are affected both indirectly, through the augmentation of universal risk factors underlying poor growth and neurodevelopment, and directly through HIV/ART-specific pathways, which ultimately may converge through a series of common pathogenic mechanisms. In the era of universal ART, a better understanding of these pathways is crucial to inform future prevention and intervention strategies.

Longitudinal trajectories of neurocognitive test performance among individuals with perinatal HIV-infection and -exposure: adolescence through young adulthood

There are an estimated 2.1 million youth less than 15 years of age living with HIV globally (the majority perinatally HIV-infected [PHIV]) and millions more perinatally HIV-exposed uninfected (PHEU) youth who are expected to survive through adolescence and into adulthood. Transitioning from adolescence to young adulthood requires adaptation to more demanding social interactions, academic pressures, and individual responsibilities which place distinct demands on neurocognitive functions. This study examined longitudinal trajectories of neurocognitive test performance in the domains of processing speed (PS), working memory (WM), and executive functioning (EF) among PHIV and demographically similar PHEU from adolescence through young adulthood. Data for this paper come from four time points, spanning approximately 10 years, within the Child and Adolescent Self-Awareness and Health Study (CASAH). Youth age ranged from 15 to 29 years. Longitudinal linear mixed effect models were computed for each test. Few differences in performance were found on tests of EF and WM between PHIV and PHEU youth as they aged, though PHEU youth showed significantly better PS as they aged than PHIV youth. Future research is needed to understand these vulnerable youth's neurocognitive trajectories as a function of HIV infection and -exposure, biological functions and psychosocial stressors.

In utero exposure to HIV and/or antiretroviral therapy: a systematic review of preclinical and clinical evidence of cognitive outcomes

INTRODUCION

With the increasing number of children exposed to HIV or antiretroviral therapy in utero, there are concerns that this population may have worse neurodevelopmental outcomes compared to those who are unexposed. The objective of this study was to systematically review the clinical and preclinical literature on the effects of in utero exposure to HIV and/or antiretroviral therapy (ART) on neurodevelopment.

METHODS

We systematically searched OVID Medline, PsycINFO and Embase, as well as the Cochrane Collaborative Database, Google Scholar and bibliographies of pertinent articles. Titles, abstracts, and full texts were assessed independently by two reviewers. Data from included studies were extracted. Results are summarized qualitatively.

RESULTS

The search yielded 3027 unique titles. Of the 255 critically reviewed full-text articles, 25 met inclusion criteria for the systematic review. Five articles studied human subjects and looked at brain structure and function. The remaining 20 articles were preclinical studies that mostly focused on behavioural assessments in animal models. The few clinical studies had mixed results. Some clinical studies found no difference in white matter while others noted higher fractional anisotropy and lower mean diffusivity in the brains of HIV-exposed uninfected children compared to HIV-unexposed uninfected children, correlating with abnormal neurobehavioral scores. Preclinical studies focused primarily on neurobehavioral changes resulting from monotherapy with either zidovudine or lamivudine. Various developmental and behavioural changes were noted in preclinical studies with ART exposure, including decreased grooming, decreased attention, memory deficits and fewer behaviours associated with appropriate social interaction.

CONCLUSIONS

While the existing literature suggests that there may be some neurobehavioral differences associated with HIV and ART exposure, limited data are available to substantially support these claims. More research is needed comparing neurobiological factors between HIV-exposed uninfected and HIV-unexposed uninfected children and using exposures consistent with current clinical care.

Development and reliability of the Prospective Memory Assessment for Children & Youth (PROMACY): A preliminary study in a nonclinical sample

Prospective memory (PM), "remembering to remember," has been linked to important functional outcomes in adults. Studies of PM in children and adolescents would benefit from the development and validation of developmentally appropriate clinical measures with known psychometric properties. The Prospective Memory Assessment for Children & Youth (PROMACY), a performance-based measure of PM, was developed for the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol, Memory and Executive Functioning Substudy, and includes Summary, Time-, and Event-based scores derived from eight trials with an ongoing word search task. Fifty-four healthy perinatally HIV-exposed, uninfected children and youth, mean age 13 years, 54% female, 76% Black/non-Hispanic, and 61% impoverished were included in this psychometric analysis. PROMACY Summary Scores demonstrated low, but broadly acceptable internal consistency as measured by Cronbach's alpha and Spearman-Brown. Better PROMACY performance was associated with older age, but no other demographic factors. Generally medium-sized correlations were observed between the PROMACY Summary Score and standard clinical measures of retrospective memory, working memory, executive functions, and IQ. Findings from this preliminary psychometric study of nonclinical children and youth provide cautious support for the internal consistency and construct validity of PROMACY's Summary Score that awaits replication and extension in larger samples of healthy children, youth and clinical populations.

Impact of Perinatally Acquired HIV Disease Upon Longitudinal Changes in Memory and Executive Functioning

BACKGROUND

Little is known regarding effects of perinatally acquired HIV infection (PHIV) on longitudinal change in memory and executive functioning (EF) during adolescence despite the importance of these skills for independence in adulthood.

METHODS

PHIV (n = 144) and perinatally HIV-exposed uninfected youth (PHEU, n = 79), ages 12-17, completed standardized tests of memory and EF at baseline and 2 years later. Changes from baseline for each memory and EF outcome were compared between PHEU and PHIV youth with (PHIV/C, n = 39) and without (PHIV/non-C, n = 105) history of CDC class C (AIDS-defining) diagnoses. Among PHIV youth, associations of baseline and past disease severity with memory and EF performance at follow-up were evaluated using adjusted linear regression models.

RESULTS

Participants were primarily black (79%); 16% were Hispanic; 55% were female. Mean memory and EF scores at follow-up generally fell in the low-average to average range. Pairwise comparison of adjusted mean change from baseline to follow-up revealed significantly greater change for PHIV/non-C compared with PHEU youth in only one verbal recognition task, with a difference in mean changes for PHIV/non-C versus PHEU of -0.99 (95% CI: -1.80 to -0.19; P = 0.02). Among youth with PHIV, better immunologic status at baseline was positively associated with follow-up measures of verbal recall and recognition and cognitive inhibition/flexibility. Past AIDS-defining diagnoses and higher peak viral load were associated with lower performance across multiple EF tasks at follow-up.

CONCLUSIONS

Youth with PHIV demonstrated stable memory and EF during a 2-year period of adolescence, allowing cautious optimism regarding long-term outcomes.

A systematic review of prospective memory in HIV disease: from the laboratory to daily life

OBJECTIVE

Prospective memory (PM) is described as the capacity to form and maintain an intention that is executed in response to a specific cue. Neural injury and associated neurocognitive disorders are common among persons living with HIV disease, who might therefore be susceptible to impairment in PM.

METHOD

This literature review utilized a structured qualitative approach to summarize and evaluate our current understanding of PM functioning in people living with HIV disease. 33 studies of PM in HIV+ persons met criteria for inclusion.

RESULTS

Findings showed that HIV is associated with moderate deficits in PM, which appear to be largely independent of commonly observed comorbid factors. The pattern of PM deficits reveals dysregulation of strategic processes that is consistent with the frontal systems pathology and associated executive dysfunction that characterizes HIV-associated neural injury. The literature also suggests that HIV-associated PM deficits present a strong risk of concurrent problems in a wide range of health behaviors (e.g. medication non-adherence) and activities of daily living (e.g. employment). Early attempts to improve PM in HIV disease have revealed that supporting strategic processes might be effective for some individuals.

CONCLUSIONS

HIV-associated PM deficits are common and exert a significant adverse effect on the daily lives and health of infected persons. Much work remains to be done to understand the cognitive architecture of HIV-associated PM deficits and the most efficient means to enhance PM functioning and improve health outcomes in persons living with HIV.

Lower total and regional grey matter brain volumes in youth with perinatally-acquired HIV infection: Associations with HIV disease severity, substance use, and cognition

Despite improved survival due to combination antiretroviral therapy (cART), youth with perinatally-acquired HIV (PHIV) show cognitive deficits and developmental delay at increased rates. HIV affects the brain during critical periods of development, and the brain may be a persistent reservoir for HIV due to suboptimal blood brain barrier penetration of cART. We conducted structural magnetic resonance imaging (sMRI) and cognitive testing in 40 PHIV youth (mean age=16.7years) recruited from the NIH Pediatric HIV/AIDS Cohort Study (PHACS) who are part of the first generation of PHIV youth surviving into adulthood. Historical and current HIV disease severity and substance use measures were also collected. Total and regional cortical grey matter brain volumes were compared to a group of 334 typically-developing, HIV-unexposed and uninfected youth (frequency-matched for age and sex) from the Pediatric Imaging, Neurocognition, and Genetics (PING) study (mean age=16.1years). PHIV youth had smaller (2.8-5.1%) total and regional grey matter volumes than HIV-unexposed and uninfected youth, with smallest volumes seen among PHIV youth with higher past peak viral load (VL) and recent unsuppressed VL. In PHIV youth, worse cognitive performance correlated with smaller volumes. This pattern of smaller grey matter volumes suggests that PHIV infection may influence brain development and underlie cognitive dysfunction seen in this population. Among PHIV youth, smaller volumes were also linked to substance use (alcohol use: 9.0-13.4%; marijuana use: 10.1-16.0%). In this study, collection of substance use information was limited to the PHIV cohort; future studies should also collect substance use information in controls to further address interactions between HIV and substance use on brain volume.