Relationships between markers of vascular dysfunction and neurodevelopmental outcomes in perinatally HIV-infected youth

Plasma galectin-9 relates to cognitive performance and inflammation among adolescents with vertically acquired HIV

OBJECTIVE

Adolescents with perinatally acquired HIV (AWH) are at an increased risk of poor cognitive development yet the underlying mechanisms remain unclear. Circulating galectin-9 (Gal-9) has been associated with increased inflammation and multimorbidity in adults with HIV despite antiretroviral therapy (ART); however, the relationship between Gal-9 in AWH and cognition remain unexplored.

DESIGN

A cross-sectional study of two independent age-matched cohorts from India [AWH on ART ( n  = 15), ART-naive ( n  = 15), and adolescents without HIV (AWOH; n  = 10)] and Myanmar [AWH on ART ( n  = 54) and AWOH ( n  = 22)] were studied. Adolescents from Myanmar underwent standardized cognitive tests.

METHODS

Plasma Gal-9 and soluble mediators were measured by immunoassays and cellular immune markers by flow cytometry. We used Mann-Whitney U tests to determine group-wise differences, Spearman's correlation for associations and machine learning to identify a classifier of cognitive status (impaired vs. unimpaired) built from clinical (age, sex, HIV status) and immunological markers.

RESULTS

Gal-9 levels were elevated in ART-treated AWH compared with AWOH in both cohorts (all P  < 0.05). Higher Gal-9 in AWH correlated with increased levels of inflammatory mediators (sCD14, TNFα, MCP-1, IP-10, IL-10) and activated CD8 + T cells (all P  < 0.05). Irrespective of HIV status, higher Gal-9 levels correlated with lower cognitive test scores in multiple domains [verbal learning, visuospatial learning, memory, motor skills (all P  < 0.05)]. ML classification identified Gal-9, CTLA-4, HVEM, and TIM-3 as significant predictors of cognitive deficits in adolescents [mean area under the curve (AUC) = 0.837].

CONCLUSION

Our results highlight a potential role of Gal-9 as a biomarker of inflammation and cognitive health among adolescents with perinatally acquired HIV.

Influence of HIV infection on cognition and overall intelligence in HIV-infected individuals: advances and perspectives

It is now well understood that HIV-positive individuals, even those under effective ART, tend to develop a spectrum of cognitive, motor, and/or mood conditions which are contemporarily referred to as HIV-associated neurocognitive disorder (HAND), and which is directly related to HIV-1 infection and HIV-1 replication in the central nervous system (CNS). As HAND is known to induce difficulties associated with attention, concentration, and memory, it is thus legitimate and pertinent to speculate upon the possibility that HIV infection may well influence human cognition and intelligence. We therefore propose herein to review the concept of intelligence, the concept of cells of intelligence, the influence of HIV on these particular cells, and the evidence pointing to differences in observed intelligence quotient (IQ) scores between HIV-positive and HIV-negative individuals. Additionally, cumulative research evidence continues to draw attention to the influence of the gut on human intelligence. Up to now, although it is known that HIV infection profoundly alters both the composition and diversity of the gut microbiota and the structural integrity of the gut, the influence of the gut on intelligence in the context of HIV infection remains poorly described. As such, we also provide herein a review of the different ways in which HIV may influence human intelligence via the gut-brain axis. Finally, we provide a discourse on perspectives related to HIV and human intelligence which may assist in generating more robust evidence with respect to this issue in future studies. Our aim is to provide insightful knowledge for the identification of novel areas of investigation, in order to reveal and explain some of the enigmas related to HIV infection.

The association between mental health and metabolic outcomes in youth living with perinatally acquired HIV in the Cape Town Adolescent Antiretroviral Cohort

Youth living with perinatally acquired HIV (YLPHIV) have been found to have a range of mental disorders. Some adult HIV studies have linked mental health to adverse metabolic outcomes due to dysregulation of the sympathetic nervous system and hypothalamic-pituitary-adrenal axis, but this association has not previously been explored in YLPHIV.We investigated the association of mental health measures with metabolic outcomes in YLPHIV and HIV-uninfected youth (HIV-U) and linear regression was used to assess the adjusted associations.Overall, 203 YLPHIV (median age = 10.7years; 52% female; mean duration on ART 8 years, 12% CD4 count <500 cells/µL, 18% viral load >50 copies/mL) and 44 HIV-U (median age = 10.3 years; 55% female) were enrolled. YLPHIV had higher median total cholesterol (4.2 vs 3.9 mmol/L, p = 0.049) and triglyceride (0.9 vs 0.7 mmol/L, p < 0.001) compared to HIV-U. We found higher percentage of poor functional competence (40% vs 25%, p = 0.02) and self-concept (23% vs 9%, p = 0.03) and higher depression (6% vs 2%, p < 0.01), anger (6% vs 2%, p = 0.04) and disruptive behaviour (4% vs 0%, p < 0.01) in YLPHIV as compared to HIV-U. Among YLPHIV, higher scores of anger were associated with higher total cholesterol and higher low-density lipoprotein (ß = 0.010, p = 0.041 and ß = 0.012, p = 0.048 respectively) and disruptive behaviour with higher low-density lipoprotein (ß = 0.010, p = 0.043) after adjusting for age, sex and BMIZ.This is the one of first study to investigate the association of mental health with metabolic outcomes among YLPHIV. The association of increased anger and disruptive behaviour with increased lipid concentration is a novel finding. Further longitudinal studies are needed to evaluate the causal relationships between mental health and metabolic outcomes.

Coordination of inflammatory responses in children with perinatally-acquired HIV infection

OBJECTIVE

We investigated dynamics of inflammatory biomarkers in children with perinatally-acquired HIV (PHIV) who started antiretrovirals at age <3 years and achieved sustained virologic control (HIV plasma RNA<400 copies/mL).

DESIGN

This was a retrospective analysis of inflammatory biomarkers in children enrolled in a randomized trial of early (<3 years of age) PI-based versus NNRTI-based regimens (P1060), who achieved sustained virologic control and participated in a neurodevelopmental follow-up study (P1104 s) between ages 5-11 years.

METHODS

We measured 20 inflammatory biomarkers using ELISA or chemiluminescence at onset of sustained virologic control (Tc) and at P1104 s entry (Te).

RESULTS

The 213 participants had median ages of 1.2, 1.9, and 7.0 years at antiretroviral initiation, Tc, and Te, respectively, with 138 on PI-based and 74 on NNRTI-based regimens at Tc. Eighteen markers decreased and two increased from Tc to Te (Te-Tc). Biomarker subsets, particularly cytokines, the chemokine IP-10, and adhesion molecules sICAM-1 and sVCAM-1, correlated at Tc, Te, and Te-Tc. At Tc, higher biomarker levels were associated with younger age, female sex, HIV plasma RNA ≥750,000 copies/mL, lower nadir CD4+%, lower nadir weight z-scores, and NNRTI-based treatment. Greater Te-Tc biomarker declines were associated with younger age, male sex, higher Tc biomarker levels, lower nadir CD4+%, and NNRTI-based treatment. Duration of controlled viremia and nadir height Z-scores showed mixed associations.

CONCLUSIONS

Biomarker expression showed substantial coordination. Most markers decreased after virologic control. Demographic and clinical variables associated with biomarker patterns were identified. Mechanistic studies of these biomarker patterns are needed to inform interventions to control inflammation.

Immune Dysregulation Is Associated with Neurodevelopment and Neurocognitive Performance in HIV Pediatric Populations-A Scoping Review

HIV-1 is known for its complex interaction with the dysregulated immune system and is responsible for the development of neurocognitive deficits and neurodevelopmental delays in pediatric HIV populations. Considering that HIV-1-induced immune dysregulation and its association with neurodevelopmental and neurocognitive impairments in pediatric populations are not well understood, we conducted a scoping review on this topic. The study aimed to systematically review the association of blood and cerebrospinal fluid (CSF) immune markers with neurocognitive deficits and neurodevelopmental delays in pediatric HIV populations. PubMed, Scopus, and Web of Science databases were searched using a search protocol designed specifically for this study. Studies were selected based on a set eligibility criterion. Titles, abstracts, and full texts were assessed by two independent reviewers. Data from the selected studies were extracted and analyzed by two independent reviewers. Seven studies were considered eligible for use in this context, which included four cross-sectional and three longitudinal studies. An average of 130 (±70.61) children living with HIV, 138 (±65.37) children exposed to HIV but uninfected and 90 (±86.66) HIV-negative participants were included across the seven studies. Results indicate that blood and CSF immune markers are associated with neurocognitive development/performance in pediatric HIV populations. Only seven studies met the inclusion criteria, therefore, these limited the number of significant conclusions which could have been made by using such an approach. All considered, the evidence suggests that immune dysregulation, as in the case of adult HIV populations, also has a significant association with neurocognitive performance in pediatric HIV populations.

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.

Components of metabolic syndrome associated with lower neurocognitive performance in youth with perinatally acquired HIV and youth who are HIV-exposed uninfected

We investigated the association of metabolic syndrome (MetS) and its components [abdominal obesity, elevated triglycerides (TG), low HDL cholesterol, elevated blood pressure (BP), and impaired fasting glycemia (IFG)] with neurocognitive impairment in youth with perinatally acquired HIV (YPHIV) or who are perinatally HIV-exposed uninfected (YPHEU). This was an observational study with a comparison group of 350 YPHIV and 68 YPHEU ages 10-19 years. Youth with MetS components measured between 1 year before and 3 months after a baseline neurocognitive assessment (Wechsler Intelligence Scale) were selected from the Pediatric HIV/AIDS Cohort Study (PHACS). A sub-group completed another assessment 3 years later. We assessed the association of each baseline MetS component with five standardized neurocognitive indices at baseline and changes in indices over time. At baseline, 15% of YPHIV and 18% of YPHEU met criteria for ≥ 2 MetS components. Among YPHIV, there was no association between MetS components and neurocognitive indices at baseline; however, over time, elevated baseline BP was associated with a greater decrease in mean Perceptual Reasoning scores (-4.3;95%CI: -8.8,0.3) and ≥ 2 MetS components with a greater decrease in mean Processing Speed scores (-5.1;95%CI: -9.4, -0.8). Among YPHEU, elevated TG was associated with lower mean Verbal Comprehension, Perceptual Reasoning, and Full-scale IQ scores at baseline, and IFG with lower mean Verbal Comprehension scores. Components of MetS in YPHIV (elevated BP) and YPHEU (elevated TG and IFG) were associated with lower neurocognitive performance index scores. Studies to elucidate how modifying metabolic risk factors early in life may improve neurocognitive outcomes in this population are warranted.

Plasma biomarker factors associated with neurodevelopmental outcomes in children with perinatal HIV infection and controlled viremia

OBJECTIVE

We examined relationships between plasma biomarkers and neurodevelopment in children from sub-Saharan Africa with perinatal HIV (PHIV) with controlled viremia on antiretroviral therapy (ART).

DESIGN

Longitudinal retrospective cohort study of children with controlled blood HIV replication.

METHODS

Children (N = 213; 57% girls) started ART at less than 3 years of age, had neurodevelopmental assessments (cognition, attention/impulsivity, motor proficiency, global executive functions) at 5-11 years, and achieved controlled viremia (HIV-1 RNA <400 copies/ml for ≥9 months before initial assessment). Twenty-three plasma biomarkers were measured at onset of controlled viremia, week 0 (first neurodevelopmental assessment), and week 48 (second neurodevelopmental assessment). Factor analysis was conducted at each time point. Multivariable linear regressions assessed associations between factors and neurodevelopmental scores.

RESULTS

Median age at week 0 was 7.0 years. Eighteen biomarkers loaded on six factors: a (L-10, IFNγ, IFNα2, IL-1β, IL-6, IP-10, TNFα); B (sCD163, sICAM-1, sVCAM-1, CRP); C (sE-selectin, sP-selectin); D [MIP-1β, vascular endothelial growth factor (VEGF)-A]; E (sCD14, CRP); and F (CX3CL1, MCP-1). Higher factor B scores were consistently associated with worse cognition and attention/impulsivity, and higher factor D scores with better attention/impulsivity.

CONCLUSION

These results suggest a detrimental effect of increased endothelial cell activation (sICAM-1, sVCAM-1) and monocyte/macrophage scavenger function (sCD163) and a beneficial effect of increased CCR5 ligand and HIV entry blocker MIP-1β and angiogenesis stimulant-VEGF concentrations on the neurodevelopment of children with PHIV. The model that emerges is of vascular inflammation leading to neurodevelopmental deficits. The role of persistent HIV replication in the central nervous system also needs to be further explored.

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.

Behavioral and Physical Activity Interventions for HAND

Approximately 30-50% of persons living with HIV manifest some degree of neurocognitive impairment. Even mild-to-moderate forms of HIV-associated neurocognitive disorders (HAND) can result in difficulties with everyday functioning, such as suboptimal medication adherence and impaired driving. Despite the pervasive presence and consequences of HAND, there is a significant unmet need to develop effective behavioral strategies to reduce the incidence and consequences of HAND. Although there is an absence of evidence-based behavioral interventions specific to HAND, the literature reviewed in this chapter suggest the following modifiable lifestyle factors as intervention targets: physical activity, diet, sleep, and antiretroviral medication adherence. Adoption and maintenance of these healthy lifestyle factors may reduce inflammation and oxidative stress, which, in turn, may reduce the incidence and/or severity of HAND.

Neurocognitive dysfunction in HIV-infected youth: investigating the relationship with immune activation

BACKGROUND

HIV-infected individuals are at increased risk of neurocognitive impairment compared to the general population. Studies suggest that, despite combination antiretroviral therapy (cART), HIV infection causes immune activation which results in neural damage; however, few data exist in HIV-infected youth.

METHODS

HIV-infected youth 8-26-years-old on cART with virological suppression were prospectively enrolled along with healthy controls. Neurocognitive performance was assessed by age-appropriate Wechsler Intelligence Scales. Soluble and cellular markers of T-lymphocyte and monocyte activation were measured by ELISA and flow cytometry, respectively.

RESULTS

45 HIV-infected subjects and 21 controls were enrolled. Markers of T-cell and monocyte activation were higher in the HIV-infected subjects compared to controls, but proportions of inflammatory and patrolling monocytes were similar. Although there were no significant differences in neurocognitive scores between the HIV-infected and control groups, scores were low-average for four of five testing domains for the HIV-infected subjects and average for all five in the controls, and % of HIV-infected subjects with scores classified as 'low average' or below was higher than in the controls. Variables most associated with neurocognitive performance among HIV-infected subjects included activated CD4⁺ T-cells (% CD4+CD38+HLA-DR), monocyte activation (soluble CD14), HIV duration, age and sex.

CONCLUSIONS

HIV-infected youth on cART with virological suppression show subtle evidence of neurocognitive impairment compared to healthy controls, and increased immune activation appears to play a role. Additional studies are needed to develop strategic interventions beyond cART to potentially improve neurocognitive performance and/or minimize further impairment in this vulnerable population. ClinicalTrials.gov Identifier: NCT01523496.

Systemic and intrathecal immune activation in association with cerebral and cognitive outcomes in paediatric HIV

Despite treatment, immune activation is thought to contribute to cerebral injury in children perinatally infected with human immunodeficiency virus (HIV). We aimed to characterize immune activation in relation to neuroimaging and cognitive outcomes. We therefore measured immunological, coagulation, and neuronal biomarkers in plasma and cerebrospinal fluid (CSF) samples of 34 perinatally HIV-infected children aged 8–18 years, and in plasma samples of 37 controls of comparable age, sex, ethnicity, and socio-economic status. We then compared plasma biomarker levels between groups, and explored associations between plasma/CSF biomarkers and neuroimaging and cognitive outcomes using network analysis. HIV-infected children showed higher plasma levels of C-reactive protein, interferon-gamma, interferon-gamma-inducible protein-10, and monocyte chemoattractant protein-1 than controls. In HIV-infected participants, plasma soluble CD14 was positively associated with microstructural white matter (WM) damage, and plasma D-dimer was negatively associated with WM blood flow. In CSF, IL-6 was negatively associated with WM volume, and neurofilament heavy-chain (NFH) was negatively associated with intelligence quotient and working memory. These markers of ongoing inflammation, immune activation, coagulation, and neuronal damage could be used to further evaluate the pathophysiology and clinical course of cerebral and cognitive deficits in perinatally acquired HIV.

Focus groups inform a mobile health intervention to promote adherence to a Mediterranean diet and engagement in physical activity among people living with HIV

Background

A personalized mobile health intervention (iSTEP) aims to promote a Mediterranean diet and increase physical activity, thereby improving neurocognitive functioning among persons living with HIV (PLWH). This article describes a qualitative study conducted to develop iSTEP for PLWH, including assessment of diet habits and preferences for tracking physical activity.

Method

Two focus groups, with seven and 13 PLWH respectively, discussed barriers and facilitators of a healthy diet and provided feedback to refine iSTEP components, including the feasibility of using a Fitbit and the content of text messages designed to encourage improved diet and physical activity.

Results

Focus group discussions revealed several healthy diet barriers, including housing instability, time required for food preparation, cost of healthy food, depression, gastrointestinal issues, physical disability, and changes in appetite since HIV diagnosis. Participant-identified healthy diet facilitators included affordable price options for healthy food, a structured food plan, desire to modify appearance or weight, access to medical professionals, motivation for disease prevention, and social support. Participants endorsed wearing a Fitbit on the wrist and receiving text messages as useful methods to monitor and encourage a better diet and greater physical activity.

Conclusions

These findings assisted the expansion of a mobile health intervention that promotes health behaviors in order to improve neurocognitive outcomes among PLWH.

Trial registration

NCT03123731, prospectively registered on ClinicalTrials.gov, April 21, 2017.

Absence of neurocognitive disadvantage associated with paediatric HIV subtype A infection in children on antiretroviral therapy

Introduction

Infection with HIV subtype A has been associated with poorer neurocognitive outcomes compared to HIV subtype D in Ugandan children not eligible for antiretroviral therapy (ART). In this study, we sought to determine whether subtype‐specific differences are also observed among children receiving ART.

Materials and Methods

Children were recruited from a clinical trial in which they were randomized to receive either lopinavir (LPV)‐ or non‐nucleoside reverse transcriptase inhibitor (NNRTI)‐ based ART (NCT00978068). Age at initiation of ART ranged from six months to six years. HIV subtype was determined by PCR amplification and population sequencing of the pol region derived from peripheral blood mononuclear cell DNA, followed by application of the REGA and Recombinant Identification Programme algorithms. General cognition was assessed using the Kaufman Assessment Battery for Children (Second Edition), attention using the Test of Variables of Attention, and motor skills using the Bruininks‐Oseretsky Test of Motor Proficiency (Second Edition). Home environment was assessed using the Home Observation for the Measurement of the Environment (HOME). Age‐adjusted test z‐scores were entered into a regression model that adjusted for sex, socio‐economic status score, HOME score, years of schooling, and ART treatment type.

Results

One hundred and five children were tested; median (interquartile range) age was 7.05 years (6.30 to 8.44), CD4 count was 867.7 cells/mm³ (416.0 to 1203.5), and duration on ART was 4.03 years (3.55 to 4.23). Seventy‐eight children had HIV subtype A and 27 had subtype D; the groups had comparable home and socio‐economic status, except that there were more males among children infected with subtype A than D (64.7% vs. 35.3%, p = 0.02). There were no differences between the subtypes in general cognition (estimated mean difference: 0.20; 95% CI: −0.11 to 0.50); p = 0.21), attention (−0.18, 95% CI: −0.60 to 0.24, p = 0.41) and motor skills (1.60, 95% CI: −0.84 to 4.04, p = 0.20).

Conclusions

Our results imply that ART may diminish the neurocognitive disadvantage seen in treatment‐naïve HIV‐infected children with subtype A.

Amino Acid Concentrations in HIV-Infected Youth Compared to Healthy Controls and Associations with CD4 Counts and Inflammation

Amino acids play critical roles in metabolism, cell function, body composition and immunity, but little data on plasma amino acid concentrations in HIV are available. We evaluated plasma amino acid concentrations and associations with CD4 counts and inflammatory biomarkers in HIV-infected youth. HIV-infected subjects with a high (≥500 cells/mm³) and low (<500 cells/mm³) current CD4⁺ T cell counts were compared to one another and to a matched healthy control group. Plasma concentrations of 19 amino acids were determined with an amino acid analyzer. Plasma levels of interleukin-6, tumor necrosis factor receptor-I, and soluble vascular cellular adhesion molecule-I were also measured. Seventy-nine HIV-infected subjects (40 and 39 with high and low CD4⁺ T cell counts, respectively) and 40 controls were included. There were no differences in amino acid concentrations between HIV-infected subjects with high or low CD4⁺ T cell counts. When combined, the HIV-infected group exhibited significantly lower median plasma concentrations compared to controls for total, essential, branched-chain and sulfur amino acids, as well as for 12 individual amino acids. Glutamate was the only amino acid that was higher in the HIV-infected group. There were no significant correlations between amino acid endpoints and inflammatory biomarkers for either HIV-infected group or controls. Plasma amino acid concentrations were lower in HIV-infected youth compared to healthy controls, regardless of immune status, while glutamate concentrations were elevated. These findings can inform future interventional studies designed to improve metabolic and clinical parameters influenced by amino acid nutriture.

Learning and Memory in Children and Adolescents With Perinatal HIV Infection and Perinatal HIV Exposure

BACKGROUND

Learning and memory in youth with perinatally acquired HIV (PHIV) are poorly understood, despite their importance for academic, healthcare and daily functioning.

METHODS

PHIV (n = 173) and perinatally HIV-exposed but uninfected (PHEU, n = 85) participants (aged 9-19 years) in a substudy of the Pediatric HIV/AIDS Cohort Study completed age-standardized tests of verbal and visual learning and delayed memory. Linear regression models implemented via generalized estimating equations were used to compare memory measures in PHEU participants versus PHIV youth with and without Centers for Disease Control and Prevention class C diagnosis (PHIV-C, n = 45 and PHIV-non-C, n = 128, respectively), adjusting for sociodemographic covariates.

RESULTS

Participants (mean age = 14.10 years) were 54% female, 75% Black and 18% Hispanic. Although unadjusted analyses showed significantly lower visual recognition memory and verbal delayed recall for PHIV-C compared with PHEU participants and lower verbal learning for PHIV-C and non-C groups compared with PHEU, differences persisted only for visual recognition memory after adjusting for sociodemographic covariates. For PHIV youth, current CD4% <25 was associated with poorer verbal learning, and older age at peak viral load was associated with poorer verbal delayed recall and design memory.

CONCLUSIONS

Youth with PHIV, particularly those with Centers for Disease Control and Prevention class C diagnosis, showed poorer performance on some measures of learning and memory compared with PHEU. Although group differences in verbal memory were largely attributable to sociodemographic characteristics, associations of class C diagnosis with poorer visual recognition memory and of current CD4% with poorer verbal learning suggest subtle effects of HIV on learning and memory in youth with PHIV.

Efavirenz and ritonavir-boosted lopinavir use exhibited elevated markers of atherosclerosis across age groups in people living with HIV in Ethiopia

BACKGROUND

HIV patients on highly-active antiretroviral therapy (HAART) have shown elevated incidence of dyslipidemia, lipodystrophy, and markers of cardiovascular disease. Evidence is beginning to emerge that implicates efavirenz (EFV) as a potential mediator of early on-set cardiovascular disease.

METHODS

Pediatric and adult HIV-infected HAART-naïve, EFV-treated, nevirapine (NVP)-treated, and ritonavir-boosted lopinavir (LPV/r)-treated subjects were recruited from Black Lion Hospital in Addis Ababa, Ethiopia. Pulse wave velocity (PWV), carotid intima-media thickness (cIMT), carotid arterial stiffness, brachial artery flow-mediated dilation (FMD), body mass index, waist-to-hip circumference ratio, and skinfold thickness were measured. CD4+ cell count, fasting glucose, lipoprotein profiles and triglycerides were also determined. Results were segmented into pediatric (6-17 years of age), young adults (25-39 years old) and older adults (40-60 years old).

RESULTS

PWV was generally elevated in EFV- and LPV/r-treated subjects compared to NVP-treated subjects across age groups. cIMT was elevated in EFV- and LPV/r-treated compared to NVP-treated older adults and in EFV-treated compared to HAART-naïve older adults. FMD was impaired in EFV- and LPV/r-treated compared to HAART-naïve younger adults, in EFV-treated compared to NVP-treated young and older adults, and in LPV/r-treated compared to NVP-treated older adults. Differences in lipoprotein profiles and skinfold thickness with HAART regimen were observed in pediatric and young adults, but less so in older adults.

CONCLUSIONS

Whereas LPV/r and other protease inhibitors have long been recognized as mediators of HIV/HAART-associated atherosclerosis, this report supports the emerging evidence that EFV may also mediate cardiovascular disease in people living with HIV on HAART.

Of mice and monkeys: can animal models be utilized to study neurological consequences of pediatric HIV-1 infection?

Pediatric human immunodeficiency virus (HIV-1) infection remains a global health crisis. Children are much more susceptible to HIV-1 neurological impairments than adults, which can be exacerbated by coinfections. Neurological characteristics of pediatric HIV-1 infection suggest dysfunction in the frontal cortex as well as the hippocampus; limited MRI data indicate global cerebral atrophy, and pathological data suggest accelerated neuronal apoptosis in the cortex. An obstacle to pediatric HIV-1 research is a human representative model system. Host-species specificity of HIV-1 limits the ability to model neurological consequences of pediatric HIV-1 infection in animals. Several models have been proposed including neonatal intracranial injections of HIV-1 viral proteins in rats and perinatal simian immunodeficiency virus (SIV) infection of infant macaques. Nonhuman primate models recapitulate the complexity of pediatric HIV-1 neuropathogenesis while rodent models are able to elucidate the role specific viral proteins exert on neurodevelopment. Nonhuman primate models show similar behavioral and neuropathological characteristics to pediatric HIV-1 infection and offer a stage to investigate early viral mechanisms, latency reservoirs, and therapeutic interventions. Here we review the relative strengths and limitations of pediatric HIV-1 model systems.

Neurologic disease in HIV-infected children and the impact of combination antiretroviral therapy

The prevalence of HIV-associated neurocognitive impairment in perinatally HIV-infected children has declined since the introduction of combination antiretroviral therapy (cART). Early initiation of cART in infancy has been shown to positively impact neurodevelopment; however, children continue to be diagnosed with HIV outside of the early infancy period and can experience subtle to severe neurocognitive deficits despite cART. The causes of these neurocognitive deficits despite effective cART are multifactorial and likely include continued viral replication in the CNS, ongoing neuroinflammation, irreversible CNS injury prior to cART initiation, neurotoxic effects of cART, and socioeconomic and psychosocial effects. Many aspects of our understanding of HIV-associated neurocognitive disorders have emerged from research in adult patients, but perinatally HIV-infected children represent a very different population. These children were exposed to HIV during a period of rapid brain development and have lifelong infection and potential lifelong cART exposure. HIV is no longer a rapidly fatal disease, and most HIV-infected children in resource-rich countries are living into adulthood. It is therefore critical to optimize neurocognitive outcomes of these youth. This review summarizes current understanding of the pathogenesis of HIV-associated CNS infection and the impact of cART on neurocognitive function in children and adolescents and discusses important areas for future research.

Perinatally acquired HIV infection: long-term neuropsychological consequences and challenges ahead

Over the past three decades, perinatal HIV infection in the United States has evolved from a fatal disease to a manageable chronic illness. As the majority of youth with perinatal HIV infection age into adolescence and adulthood, management of this stigmatizing, transmittable disease in the backdrop of a cadre of environmental stressors presents challenges beyond those of other chronic illnesses. The neurologic and neuropsychological consequences of this neurotropic virus have important implications for the successful navigation of responsibilities related to increasingly independent living of this aging population. This article will review the neurologic and neuropsychological consequences of perinatal HIV infection and concomitant factors in the era of highly active antiretroviral therapy and will provide an overview of the neuropathology, pathogenesis, neuroimaging findings, and treatment of perinatal HIV infection, as well as recommendations for service provision and future research.

Biomarkers and neurodevelopment in perinatally HIV-infected or exposed youth: a structural equation model analysis

OBJECTIVE

To examine the relationship between markers of vascular dysfunction and neurodevelopmental outcomes in perinatally HIV-infected (PHIV+) and perinatally HIV-exposed but uninfected (PHEU) youth.

DESIGN

Cross-sectional design within a prospective, 15-site US-based cohort study.

METHODS

Neurodevelopmental outcomes were evaluated in relation to nine selected vascular biomarkers in 342 youth (212 PHIV+, 130 PHEU). Serum levels were assessed for adiponectin, C-reactive protein (CRP), fibrinogen, interleukin-6 (IL-6), soluble vascular cell adhesion molecule-1 (sVCAM-1), E-selectin (sE-selectin), monocyte chemoattractant protein (sMCP-1), intercellular adhesion molecule-1 (sICAM-1), and P-selectin (sP-selectin). The Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) was administered at entry, yielding a Full-Scale IQ score, and four index scores. Factor analysis was conducted to reduce the biomarkers to fewer factors with related biological roles. Structural equation models (SEMs) were used to measure associations between resulting factors and WISC-IV scores.

RESULTS

Mean participant age was 11.4 years, 54% were female, 70% black. The nine biomarkers were clustered into three factor groups: F1 (fibrinogen, CRP, and IL-6); F2 (sICAM-1 and sVCAM-1); and F3 (MCP-1, sP-selectin, and sE-selectin). Adiponectin showed little correlation with any factor. SEMs revealed significant negative association of F1 with WISC-IV processing speed score in the total cohort. This effect remained significant after adjusting for HIV status and other potential confounders. A similar association was observed when restricted to PHIV+ participants in both unadjusted and adjusted SEMs.

CONCLUSION

Aggregate measures of fibrinogen, CRP, and IL-6 may serve as a latent biomarker associated with relatively decreased processing speed in both PHIV+ and PHEU youth.

Reproductive health decision-making in perinatally HIV-infected adolescents and young adults

With widespread access to antiretroviral therapy in the United States, many perinatally HIV-infected (PHIV+) children are surviving into adolescence and adulthood, becoming sexually active and making decisions about their reproductive health. The literature focusing on the reproductive decisions of individuals behaviorally infected with HIV can serve as a springboard for understanding the decision-making process of PHIV+ youth. Yet, there are many differences that critically distinguish reproductive health and related decision-making of PHIV+ youth. Given the potential public health implications of their reproductive decisions, better understanding of factors influencing the decision-making process is needed to help inform the development of salient treatment and prevention interventions. To begin addressing this understudied area, a "think tank" session, comprised of clinicians, medical providers, and researchers with expertise in the area of adolescent HIV, was held in Bethesda, MD, on September 21, 2011. The focus was to explore what is known about factors that influence the reproductive decision-making of PHIV+ adolescents and young adults, determine what important data are needed in order to develop appropriate intervention for PHIV+ youth having children, and to recommend future directions for the field in terms of designing and carrying out collaborative studies. In this report, we summarize the findings from this meeting. The paper is organized around the key themes that emerged, including utilizing a developmental perspective to create an operational definition of reproductive decision-making, integration of psychosocial services with medical management, and how to design future research studies. Case examples are presented and model program components proposed.

Neurodevelopment in perinatally HIV-infected children: a concern for adolescence

Globally, an estimated 3.4 million children are living with HIV, yet little is known about the effects of HIV and antiretroviral treatment (ART) on the developing brain, and the neurodevelopmental and behavioural outcomes of perinatally HIV-infected (PHIV+) adolescents. We reviewed the literature on neurodevelopmental outcomes in PHIV+ children and adolescents, and summarized the current evidence on behaviour, general cognition, specific domains, hearing and language, school performance and physical disabilities due to neurological problems. Evidence suggests that PHIV+ children do not perform as well as controls on general cognitive tests, processing speed and visual-spatial tasks, and are at much higher risk for psychiatric and mental health problems. Children with AIDS-defining diagnoses are particularly at risk for poorer outcomes. A striking finding is the lack of published data specific to the adolescent age group (10-25 years), particularly from resource-constrained countries, which have the highest HIV prevalence. In addition, extreme heterogeneity in terms of timing and source of infection, and antiretroviral experience limits our ability to summarize findings of studies and generalize results to other settings. Due to the complex nature of the developing adolescent brain, environmental influences and variation in access to ART, there is an urgent need for research on the longitudinal trajectory of neurodevelopment among children and adolescents perinatally infected with HIV, especially in high burden resource-constrained settings.

Impact of HIV severity on cognitive and adaptive functioning during childhood and adolescence

BACKGROUND

The influence of disease severity on cognitive and adaptive functioning in perinatally HIV-infected youth with (PHIV+/C) and without (PHIV+/NoC) a previous AIDS-defining illness (Centers for Disease Control and Prevention Class C event), compared with perinatally HIV-exposed but uninfected youth (PHEU) is not well understood.

METHODS

This was a cross-sectional analysis of cognitive and adaptive functioning in PHIV+/C (n = 88), PHIV+/NoC (n = 270) and PHEU (n = 200) youth aged 7-16 years, from a multisite prospective cohort study. Youth and caregivers completed the Wechsler Intelligence Scale for Children, Fourth Edition and the Adaptive Behavior Assessment System, Second Edition, respectively. We compared means and rates of impairment between groups, and examined associations with other psychosocial factors.

RESULTS

Overall mean scores on measures of cognitive and adaptive functioning were in the low average range for all 3 groups. After adjustment for covariates, mean full-scale intelligence quotient scores were significantly lower for the PHIV+/C group than the PHIV+/NoC and PHEU groups (mean = 77.8 versus 83.4 and 83.3, respectively), whereas no significant differences were observed between the PHEU and PHIV+/NoC groups in any domain. Lower cognitive performance for the PHIV+/C group was primarily attributable to a prior diagnosis of encephalopathy. No significant differences between groups were observed in adaptive functioning.

CONCLUSION

For long-term survivors, youth with HIV infection and a prior Centers for Disease Control and Prevention Class C event have higher risk for cognitive but not adaptive impairment regardless of current health status; this finding appears attributable to a previous diagnosis of encephalopathy. Early preventive therapy may be critical in reducing risk of later neurodevelopmental impairments.

T-cell activation and neurodevelopmental outcomes in perinatally HIV-infected children

OBJECTIVE

To evaluate baseline T-cell activation and neurodevelopmental outcomes over time in a cohort of perinatally HIV-infected (PHIV-infected) children with severe disease.

DESIGN

Pediatric AIDS Clinical Trials Group protocol 366 (PACTG 366) was a partially randomized, open-label, multicenter 96-week antiretroviral treatment-algorithm study. Neurodevelopmental status, measured by age-dependent evaluations (Bayley scales of infant development-II; Wechsler preschool and primary scale of intelligence-revised; Wechsler intelligence scale for children-III), was a secondary outcome.

METHODS

Linear mixed models were used to assess the baseline and follow-up neurodevelopmental outcomes in relation to immune activation, measured by CD38 and human leukocyte antigen (HLA) DR expression on peripheral CD4(+) and CD8(+) T cells at study baseline. Models were adjusted for age, sex, race/ethnicity, baseline viral load, baseline CD4%, cytomegalovirus (CMV) infection status at entry, study treatment arms, central nervous system penetrance score of antiretroviral regimen at entry, and viral load response 16 weeks postentry.

RESULTS

Among 126 PACTG 366 enrollees who were at least 1 year old and had both immune activation and age-appropriate neurodevelopmental assessments at baseline, 80 (63%) were black non-Hispanic, 71 (56%) males, 122 (97%) were on antiretrovirals, and 45 (36%) were in Centers for Disease Control and Prevention (CDC) disease category C at entry. CD4(+)CD38(+)HLADR(+)%, CD4(+)CD38(-)HLADR(+)%, and CD8(+)CD38(+)HLADR(+)% were positively associated with full-scale Intelligence Quotient scores (FSIQ) (slope = 0.18, 0.70, and 0.15, respectively; P = 0.02, 0.03, and 0.04, respectively). CD4(+)CD38(+)HLADR(-)% was negatively associated with FSIQ (slope =  -0.16, P = 0.01).

CONCLUSION

Contrary to HIV-infected adults, in PHIV-infected children higher CD4(+)CD38(+)HLADR(+)% may be associated with a neuroprotective effect and higher percentage of CD4(+)CD38(+) but HLADR(-) T cells may be deleterious.

Associations of medically documented psychiatric diagnoses and risky health behaviors in highly active antiretroviral therapy-experienced perinatally HIV-infected youth

The Longitudinal Epidemiologic Study to Gain Insight into HIV/AIDS in Children and Youth (LEGACY) study is a prospective, multisite, longitudinal cohort of U.S. HIV-infected youth. This analysis was limited to perinatally HIV-infected youth (n=197), 13 years and older, with selected variables completely abstracted from HIV diagnosis through 2006. We evaluated relationships between ever having one or more nonsubstance related medically documented psychiatric diagnoses and three risky health behaviors (substance abuse, preadult sexual activity, and treatment adherence problems) recorded between 2001 and 2006. Logistic regression was used for all binary outcomes and participant age was included as a covariate when possible. All 197 participants included in the analysis were prescribed antiretroviral therapy during the study period; 110 (56%) were female, 100 (51%) were black non-Hispanic, and 86 (44%) were Hispanic; mean age at the last visit was 16.8 years, ranging from 13 to 24 years. One hundred forty-six (74%) participants had a history of at least one risky health behavior. There were 108 (55%) participants with at least one medically documented psychiatric diagnosis, 17 (9%) with at least one record of substance abuse, 12 (6%) with documented preadult sexual activity, and 142 (72%) participants with reported adherence problems. In the final model, a history of at least one psychiatric diagnosis was associated with having at least one of the three risky behaviors (odds ratio [OR]=2.33, p=0.015). There is a need for a continued close partnership between HIV specialty care providers and mental health services treating perinatally HIV-infected youth with an added focus on improving treatment adherence.