Cerebral injury in perinatally HIV-infected children compared to matched healthy controls

Medical comorbidities and lower myelin content are associated with poor cognition in young adults with perinatally acquired HIV

OBJECTIVE

Approximately 40% of adults living with HIV experience cognitive deficits. Little is known about the risk factors for cognitive impairment and its association with myelin content in young adults living with perinatally acquired HIV (YApHIV), which is assessed in our cross-sectional study.

DESIGN

A prospective, observational cohort study.

METHODS

All participants underwent an 11-test cognitive battery and completed medical and social history surveys. Cognitive impairment was defined as Z scores falling at least 1.5 SD below the mean in at least two domains. Twelve participants underwent myelin water imaging. Neuroimaging data were compared to age and sex-matched HIV-uninfected controls. Regression analyses were used to evaluate for risk factors of lower cognitive domain scores and association between myelin content and cognition in YApHIV.

RESULTS

We enrolled 21 virally suppressed YApHIV across two sites in the United States. Ten participants (48%) met criteria for cognitive impairment. Participants with any non-HIV related medical comorbidity scored lower across multiple cognitive domains compared to participants without comorbidities. Myelin content did not differ between YApHIV and controls after adjusting for years of education. Lower cognitive scores were associated with lower myelin content in the cingulum and corticospinal tract in YApHIV participants after correcting for multiple comparisons.

CONCLUSION

Poor cognition in YApHIV may be exacerbated by non-HIV related comorbidities as noted in older adults with horizontally acquired HIV. The corticospinal tract and cingulum may be vulnerable to the legacy effect of untreated HIV in infancy. Myelin content may be a marker of cognitive reserve in YApHIV.

Cognitive impairment in children and adolescents living with perinatal HIV disease in the ART era: a meta-analysis

Background

Despite improved survival and overall health outcomes from modern antiretroviral therapy (ART), children and adolescents living with HIV are facing pervasive impairments in neurodevelopment including cognitive impairment, but there remains a lack of consensus on the cognitive domains that are affected in those children and adolescents. The objective of this meta-analysis was to evaluate the impact of perinatal HIV-infection on executive function, working memory, and speed of information processing in the ART era.

Methods

The PubMed database was searched for studies published between 1997 and 2024, plus additional search with the ScienceDirect, bioRxiv, and medRxiv databases. A meta-analysis was conducted on thirty-five studies published between 2012 and 2023 that encompassed a total of 4066 perinatally-infected HIV patients, 2349 HIV-exposed uninfected (HEU) controls, and 2466 HIV-unexposed, uninfected (HUU) controls. Performance scores on executive function, working memory, and processing speed were pooled using random-effects meta-analysis.

Findings

Compared to HEU and HUU controls, perinatally HIV-infected children and adolescents presented with significant impairments in processing speed (Hedges g = -0.64, p < 0.00001), working memory (Hedges g = -0.69, p < 0.00001), and to a lesser degree, executive function (Hedges g = -0.35, p = 0.02). Meta-regression analysis suggested that the effect estimate of processing speed impairment negatively correlated with Gross National Income (GNI) per capita of the study countries (CALHIV vs HUU, p = 0.0016; CALHIV vs HEU, p = 0.0019), even though HIV-infected cases were compared to sociodemographically matched HUU controls from the same countries. Sub-group meta-analyses with participants from high-income or low-/middle-income countries provided further evidence suggesting that the performance gap between HIV-infected cases and HUU/HEU controls may be larger in low-/middle-income countries than high-income countries.

Interpretation

In the ART era, cognitive impairment (especially reduced processing speed and working memory) persists in children and adolescents living with HIV. These impairments may be more pronounced among those children and adolescents living with HIV in low-income countries, suggesting that there may be global health inequities in treatment outcomes with perinatal HIV-infection. However, meta-analysis and meta-regression analysis have their limitations, which calls for future collaborative multi-country international studies to directly investigate this important topic. Nevertheless, there is an unmet need to assure equity in timely assessments and interventions to optimize neurocognitive development and outcomes among children and adolescents with perinatal HIV globally.

Funding

This research was supported in part by NIH R01MH108466, NIH R56NS124422, and NIH R01NS124422.

Motivation levels and white matter microstructure in children living with HIV

Central nervous system involvement in HIV infection leads to neurobehavioural sequelae. Although apathy is a well-recognised symptom in adults living with HIV linked to alterations in brain structure, there is scarce research examining motivation in children living with HIV (CLWH). We used the Children's Motivation Scale (CMS; normative mean = 50, SD = 10) to assess motivation levels in 76 CLWH aged 6-16 years (63 on antiretroviral therapy [ART]; 13 ART-naïve slow progressors) in South Africa. Overall, CLWH scored low on the CMS (mean = 35.70 [SD = 5.87]). Motivation levels were significantly reduced in children taking ART compared to ART-naïve slow progressors (p = 0.02), but were not correlated with markers of HIV disease (CD4 + cell count or viral load), or neurocognitive function (p > 0.05). CMS scores were correlated with diffusion tensor imaging metrics of white matter microstructure in specific frontostriatal brain regions (p < 0.05). On multiple regression, associations with the anterior limb of the internal capsule, a subcortical white matter region, remained significant after adjusting for potential confounders. These findings suggest that reduced motivation may be an important neurobehavioural symptom in CLWH and may reflect changes in white matter microstructure of frontostriatal brain regions.

Whole-brain MR spectroscopic imaging reveals regional metabolite abnormalities in perinatally HIV infected young adults

Perinatally acquired HIV (PHIV) has been associated with brain structural and functional deficiencies, and with poorer cognitive performance despite the advent of antiretroviral therapy (ART). However, investigation of brain metabolite levels in PHIV measured by proton magnetic resonance spectroscopy (MRS) methods, is still limited with often inconclusive or contradictory findings. In general, these MRS-based methods have used a single voxel approach that can only evaluate metabolite concentrations in a few select brain anatomical regions. Additionally, most of the published data have been on children perinatally infected with HIV with only a few studies examining adult populations, though not exclusively. Therefore, this prospective and cross-sectional study aims to evaluate metabolite differences at the whole-brain level, using a unique whole-brain proton magnetic resonance spectroscopy imaging (MRSI) method, in a group of PHIV infected young adults (N = 28) compared to age and gender matched control sample (N = 28), and to find associations with HIV clinical factors and neurocognitive scores. MRSI data were acquired on a 3T scanner with a TE of 70 ms. Brain metabolites levels of total N-acetylaspartate (tNAA), total choline (tCho) and total creatine (tCre), as well as ratios of tNAA/tCre, tCho/tCre, and tNAA/tCho, were obtained from the whole brain level and evaluated at the level of gray matter (GM) and white matter (WM) tissue types and anatomical regions of interest (ROI). Our results indicate extensive metabolic abnormalities throughout the brains of PHIV infected subjects with significantly elevated levels of tCre and tCho, notably in GM regions. Decreases in tNAA and ratios of tNAA/tCre and tNAA/tCho were also found mostly in WM regions. These metabolic alterations indicate increased glial activation, inflammation, neuronal dysfunction, and energy metabolism in PHIV infected individuals, which correlated with a reduction in CD4 cell count, and lower cognitive scores. Our findings suggest that significant brain metabolite alterations and associated neurological complications persist in the brains of those with PHIV on long-term ART, and advocates the need for continued monitoring of their brain health.

Brain Differences in Adolescents Living With Perinatally Acquired HIV Compared With Adoption Status Matched Controls: A Cross-sectional Study

BACKGROUND AND OBJECTIVES

Despite effective combination antiretroviral therapy (cART), adolescents with perinatally acquired HIV (PHIV) exhibit cognitive impairment, of which structural changes could be the underlying pathophysiologic mechanism. Prior MRI studies found lower brain volumes, higher white matter (WM) hyperintensity (WMH) volume, lower WM integrity, and differences in cerebral blood flow (CBF). However, these findings may be confounded by adoption status, as a large portion of adolescents with PHIV have been adopted. Adoption has been associated with malnutrition and neglect, which, in turn, may have affected brain development. We investigated the long-term effects of PHIV on the brain, while minimizing the confounding effect of adoption status.

METHODS

We determined whole-brain gray matter (GM) and WM volume with 3D T1-weighted scans; total WMH volume with fluid-attenuated inversion recovery; CBF in the following regions of interest (ROIs): WM, GM, and subcortical GM with arterial spin labeling; and whole-brain WM microstructural markers: fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) with diffusion tensor imaging in cART-treated adolescents with PHIV visiting our outpatient clinic in Amsterdam and controls matched for age, sex, ethnic origin, socioeconomic status, and adoption status. We assessed differences in neuroimaging parameters between adolescents with PHIV and controls using linear regression models adjusted for age and sex and applied multiple comparison correction.

RESULTS

Thirty-five adolescents with PHIV and 38 controls were included with a median age of 14.9 (interquartile range [IQR]: 10.7-18.5) and 15.6 (IQR: 11.1-17.6) years, respectively, with a similar rate of adoption. We found a lower overall FA (beta = -0.012; p < 0.014, -2.4%), a higher MD (beta = 0.014, p = 0.014, 1.3%), and a higher RD (beta = 0.02, p = 0.014, 3.3%) in adolescents with PHIV vs adoption-matched controls, but no differences in AD. We found comparable GM, WM, and WMH volume and CBF in ROIs between adolescents with PHIV and controls. We did not find an association between cognitive profiles and WM microstructural markers in adolescents with PHIV.

DISCUSSION

Irrespective of adoption status, adolescents with PHIV exhibited subtle lower WM integrity. Our findings may point toward early-acquired WM microstructural alterations associated with HIV.

Biomarkers of Tuberculous Meningitis and Pediatric Human Immunodeficiency Virus on the African Continent

Biomarkers in body fluids are helpful objective tools in diagnosis, prognosis and monitoring of (therapeutic) responses of many neurological diseases. Cerebrospinal fluid (CSF) biomarkers are part of the diagnostic toolbox for infectious neurological diseases. Tuberculous meningitis (TBM) and Human immunodeficiency virus (HIV), are important burdens of disease in Africa and can negatively affect brain health. Two thirds of the world's population of people living with HIV reside in sub-Saharan Africa and 25% of the global burden of tuberculosis (TB) is carried by the African continent. Neuroinflammation and damage of specific neuronal cell types are key constituents in the pathophysiology of these central nervous system (CNS) diseases, and important potential sources of circulating biomarkers. In this review, we summarize current research in the use of biomarkers in TBM and pediatric HIV as case demonstrations for high prevalence neurological diseases in Africa. Inflammatory molecules, primarily when detected in CSF, appear to have diagnostic value in these diseases, especially when measured as profiles. Brain injury molecules, such as S100, Neuron specific enolase and glial fibrillary acidic protein may have prognostic value in TBM, but more studies are needed. There is a need for more cost-economic and high sensitivity technologies to drive further biomarker discoveries and translate into healthcare improvements for these important healthcare problems in a globally fair way.

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.

Fatigue in children and adolescents perinatally infected with human immunodeficiency virus: an observational study

BACKGROUND

Fatigue is common among adults living with human immunodeficiency virus (HIV) as well as children with a chronic disease (CCD). Fatigue can have disastrous effects on health status, including health related quality of life (HRQOL). Even so, fatigue is underexplored in children and adolescents perinatally infected with HIV (PHIV+) in the Netherlands. The objective of this observational study is to explore fatigue in PHIV+ and its association with their HRQOL.

METHODS

We measured HRQOL and fatigue using the Pediatric Quality of Life Inventory™ (PedsQL 4.0) and the PedsQL Multidimensional Fatigue Scale (MFS). The PedsQL MFS encompasses three subscales: general fatigue, sleep/rest fatigue and cognitive fatigue, and a total fatigue score. We compared outcomes of PHIV+ children and adolescents in the Amsterdam University Medical Centre with three groups: 1) HIV-uninfected controls (HIV-) matched for age, sex, region of birth, socioeconomic status and adoption status, 2) CCD, and 3) the general Dutch population. Within the PHIV+ group we explored associations between fatigue and HRQOL.

RESULTS

We enrolled 14 PHIV+ (median age 10.2 years [IQR 9.2-11.4]) and 14 HIV-. Compared to CCD, PHIV+ significantly reported less general fatigue (mean difference 13.0, 95% CI 1.3 to 24.8). PHIV+ did not score significantly different on any of the other PedsQL MFS scales compared to HIV-, CCD or the general Dutch population. PHIV children scored relatively low on the cognitive fatigue scale in comparison to HIV-uninfected matched controls, CCD and the general population, although these differences did not reach significance. Among PHIV+, a lower score on total fatigue, general fatigue and cognitive fatigue was associated with a lower HRQOL score.

CONCLUSIONS

The results of this study suggest that PHIV children and adolescents do not experience more symptoms of fatigue than their healthy peers. However, PHIV children and adolescents may be more likely to experience cognitive fatigue. Fatigue in PHIV also appears to be associated with children's HRQOL. Further research should confirm these exploratory findings.

Longitudinal Assessment of Lipoprotein(a) Levels in Perinatally HIV-Infected Children and Adolescents

HIV is an independent risk factor of cardiovascular disease (CVD); therefore, perinatally HIV-infected (PHIV) children potentially have a greater CVD risk at older age. Lipoprotein(a) (Lp(a)) is an established risk factor for CVD in the general population. To evaluate a potential increased CVD risk for PHIV children, we determined their lipid profiles including Lp(a). In the first substudy, we assessed the lipid profiles of 36 PHIV children visiting the outpatient clinic in Amsterdam between 2012 and 2020. In the second substudy, we enrolled 21 PHIV adolescents and 23 controls matched for age, sex and ethnic background on two occasions with a mean follow-up time of 4.6 years. We assessed trends of lipid profiles and their determinants, including patient and disease characteristics, using mixed models. In the first substudy, the majority of PHIV children were Black (92%) with a median age of 8.0y (5.7–10.8) at first assessment. Persistent elevated Lp(a) levels were present in 21/36 (58%) children (median: 374 mg/L (209–747); cut off = 300). In the second substudy, the median age of PHIV adolescents was 17.5y (15.5–20.7) and of matched controls 16.4y (15.8–19.5) at the second assessment. We found comparable lipid profiles between groups. In both studies, increases in LDL-cholesterol and total cholesterol were associated with higher Lp(a) levels. A majority of PHIV children and adolescents exhibited elevated Lp(a) levels, probably associated with ethnic background. Nonetheless, these elevated Lp(a) levels may additionally contribute to an increased CVD risk.

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.

Altered White Matter Tracts in the Somatosensory, Salience, Motor, and Default Mode Networks in 7-Year-Old Children Living with Human Immunodeficiency Virus: A Tractographic Analysis

Introduction: Even with the increased access and early initiation of combination antiretroviral therapy, children with perinatally acquired human immunodeficiency virus (CPHIV) continue to demonstrate white matter alterations. Children perinatally HIV-exposed, but uninfected (CHEU) alike show differences in white matter integrity compared with children who are HIV-unexposed and uninfected (CHUU). Objectives: Mapping white matter connections that link gray matter regions that form resting-state (RS) functional networks may demonstrate whether structural and functional connectivity alterations in HIV infection and exposure may be related. We hypothesized reduced structural connectivity in CPHIV within the default mode network (DMN), visual, ventral DMN (vDMN), somatosensory, salience, auditory, motor, executive, basal ganglia, and posterior DMN (pDMN). We also hypothesized that CHEU will have increased structural connectivity compared with CHUU in the vDMN, somatosensory, pDMN, dorsal attention, salience, auditory, motor and basal ganglia. Methods: Study participants were 61 seven-year-old CPHIV and 46 age-matched children who are HIV uninfected (CHU) (19 CHEU). We used diffusion tensor imaging-based tractography to investigate white matter connections that link gray matter regions within RS functional networks. Results: We found altered white matter integrity in the somatosensory, salience, default mode, and motor networks of CPHIV compared with CHU. The superior temporal cortex, superior frontal cortex, and putamen were affected in all four networks and have also been reported to demonstrate morphological alterations in the same cohort. In CHEU, white matter integrity was higher in the visual network, pDMN, and motor network compared with CHUU. Conclusion: Our results suggest that altered white matter integrity may influence gray matter morphology and functional network alterations. Impact statement The long-term effects of human immunodeficiency virus (HIV) and exposure on the developing brain in the combination antiretroviral therapy era are still not well known. We use diffusion tensor imaging-based tractography to explore these effects on white matter connections that link gray matter regions within functional networks. Our findings provide a context for HIV-associated white matter and connectivity abnormalities.

Normal structural brain development in adolescents treated for perinatally acquired HIV: a longitudinal imaging study

OBJECTIVE

Cross-sectional studies, including one from our NOVICE cohort [Neurological Visual and Cognitive performance in children with treated perinatally acquired HIV (PHIV) compared with matched HIV-negative controls], have revealed that the brains of children with PHIV have lower white matter and grey matter volumes, more white matter hyperintensities (WMH) and poorer white matter integrity. This longitudinal study investigates whether these differences change over time.

METHODS

We approached all NOVICE participants to repeat MRI after 4.6 ± 0.3 years, measuring total white matter and grey matter volume, WMH volume and white matter integrity, obtained by T1-weighted, fluid-attenuated inversion recovery (FLAIR) and diffusion tensor imaging (DTI), respectively. We compared rates of change between groups using multivariable linear mixed effects models, adjusted for sex and age at enrolment. We investigated determinants of developmental deviation, and explored associations with cognitive development.

RESULTS

Twenty out of 31 (65%) PHIV-positive, and 20 out of 37 (54%) HIV-negative participants underwent follow-up MRI. Groups did not significantly differ in terms of age and sex. Over time, we found no statistically different changes between groups for white matter and WMH volumes, and for white matter integrity (P > 0.1). Total grey matter volume decreased significantly less in PHIV [group∗time 10 ml, 95% confidence interval -1 to 20, P = 0.078], but this difference in rate of change lost statistical significance after additional adjustment for height (group∗time 9 ml, 95% confidence interval -2 to 20, P = 0.112). We found no HIV-associated determinants for potential reduced grey matter pruning, nor associations with cognitive development.

CONCLUSION

While using long-term antiretroviral treatment, structural brain development of adolescents growing up with perinatally acquired HIV appears largely normal.

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.

Effects of perinatal HIV-infection on the cortical thickness and subcortical gray matter volumes in young adulthood

ABSTRACT

Brain atrophy has been observed in perinatally HIV-infected patients (PHIV) despite initiation on combined antiretroviral treatment (cART), but neuroimaging studies are limited. We aimed to evaluate cortical thickness (CT) and subcortical gray matter (GM) volumes of PHIV youths with stable immunovirological situation and with a normal daily performance.A prospective cross-sectional study was conducted. A total of 25 PHIV patients on cART and 25 HIV-negative (HIV-) controls matched by age, sex, level of education, and socioeconomic status underwent a magnetic resonance imaging scan. CAT12 toolbox was used to extract CT values from T1w images using parcellations from Desikan-Killiany atlas (DK40). To measure regional brain volumes, native segmented images were parceled in regions of interest according to the Neuromorphometrics Atlas. Neuropsychological assessment and psychopathological symptoms were documented.Fifty participants were included (60% females, median age 20 years [interquartile range, IQR 19-23], 64% Whites). No differences regarding neuropsychological tests or psychopathological symptoms were found between groups (all P > .05). All participants presented an average performance in the Fluid Intelligence (FI) test (PHIV mean: -0.12, HIV- mean: 0.24), When comparing CT, PHIV-infected patients showed thinner cortices compared with their peers in fusiform gyrus (P = .000, P = .009), lateral-orbitofrontal gyrus (P = .006, P = .0024), and right parsobitalis gyrus (P = .047). Regarding subcortical GM volumes, PHIV patients showed lower right amygdala (P = .014) and left putamen (P = .016) volumes when compared with HIV- controls. Within the PHIV group, higher CD4 count was associated with higher volumes in right putamen (B = 0.00000038, P = .045). Moreover, increased age at cART initiation and lower nadir CD4 count was associated with larger volumes in left accumbens (B = 0.0000046, P = .033; B = -0.00000008, P = .045, respectively).PHIV patients showed thinner cortices of areas in temporal, orbito-frontal and occipital lobes and lower volumes of subcortical GM volumes when compared with the HIV- control group, suggesting cortical and subcortical brain alterations in otherwise neuroasymptomatic patients. Nevertheless, larger and longitudinal studies are required to determine the impact of HIV on brain structure in PHIV patients and to further identify risk and protective factors that could be implicated.

Health-related quality of life of perinatally HIV-infected young people: a longitudinal study

Young people perinatally infected with HIV (pHIV) are at risk of a lowered health-related quality of life (HRQOL). Previous evaluation of the NeurOlogical, VIsual and Cognitive performance in HIV-infected Children (NOVICE)-cohort showed no difference in HRQOL between pHIV and matched HIV-uninfected controls (HIV-), yet a higher percentage of pHIV had impaired HRQOL. The aim of this study is to compare the change over time in HRQOL of pHIV to HIV- over a 5-year period. We used the Pediatric Quality of Life Inventory (PedsQL)™ 4.0 to repeat HRQOL assessment. High PedsQL scores indicate good HRQOL. Fifteen/33 (45.5%) pHIV and 17/37 (45.9%) HIV- completed both assessments. At the first assessment, the mean age was 13.1 years (range 8.0-18.4). PHIV scored higher than HIV- on Emotional functioning and on Total scale score. After five years, the mean age was 17.6 years (range 12.1-22.8). PHIV scored higher than HIV- on all scales, except Social functioning. PHIV did not differ significantly from the Dutch norm on either time-point. LMEM showed no difference in change over time for any of the PedsQL scales. In this study, young people with pHIV receiving high-quality health care, including monitoring of HRQOL, remain to experience a good HRQOL.

Accelerated epigenetic aging in adolescents living with HIV is associated with altered development of brain structures

We recently demonstrated that adolescents perinatally infected with HIV-1 (PHIV+) have accelerated aging as measured by a highly accurate epigenetic biomarker of aging known as the epigenetic clock. However, whether epigenetic age acceleration in PHIV+ impacts brain development at the macro- and microstructural levels of brain anatomy has not been studied. We report on a cross-sectional study of PHIV+ enrolled in the Cape Town Adolescent Antiretroviral Cohort (CTAAC). The Illumina Infinium Methylation EPIC array was used to generate DNA methylation data from the blood samples of 180 PHIV+ aged 9 to 12 years. The epigenetic clock software and method was used to estimate two measures, epigenetic age acceleration (AgeAccelerationResidual) and extrinsic epigenetic age acceleration (EEAA). Each participant underwent T1 structural magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). In order to investigate the associations of chronological age, sex, epigenetic age acceleration and treatment variables (CNS penetration effectiveness score (CPE)) of antiretroviral regimen on brain structure in PHIV+, we developed stepwise multiple regression models in R (version 3.4.3, 2017) including grey and white matter volumes, cortical thickness, cortical surface area and DTI measures of white matter microstructural integrity. The mean DNAm age (16.01 years) of the participants was higher than their mean chronological age (10.77 years). Epigenetic age acceleration contributed more to regional alterations of brain volumes, cortical thickness, cortical surface areas and neuronal microstructure than chronological age, in a range of regions. CPE positively contributed to volume of the brain stem. Understanding the drivers of epigenetic age acceleration could lead to valuable insights into structural brain alterations, and the persistence of neurocognitive disorders in seen in PHIV+ .

White matter of perinatally HIV infected older youths shows low frequency fluctuations that may reflect glial cycling

In perinatally HIV-infected (PHIV) children, neurodevelopment occurs in the presence of HIV-infection, and even with combination antiretroviral therapy (cART) the brain can be a reservoir for latent HIV. Consequently, patients often demonstrate long-term cognitive deficits and developmental delay, which may be reflected in altered functional brain activity. Our objective was to examine brain function in PHIV on cART by quantifying the amplitude of low frequency fluctuations (ALFF) and regional homogeneity (ReHo). Further, we studied ALFF and ReHo changes with neuropsychological performance and measures of immune health including CD4 count and viral loads in the HIV-infected youths. We found higher ALFF and ReHo in cerebral white matter in the medial orbital lobe for PHIV (N = 11, age mean ± sd = 22.5 ± 2.9 years) compared to controls (N = 16, age = 22.5 ± 3.0 years), with age and gender as co-variates. Bilateral cerebral white matter showed increased spontaneous regional activity in PHIV compared to healthy controls. No brain regions showed lower ALFF or ReHo in PHIV compared to controls. Higher log10 viral load was associated with higher ALFF and ReHo in PHIV in bilateral cerebral white matter and right cerebral white matter respectively after masking the outcomes intrinsic to the brain regions that showed significantly higher ALFF and ReHo in the PHIV compared to the control. Reductions in social cognition and abstract thinking in PHIV were correlated with higher ALFF at the left cerebral white matter in the left medial orbital gyrus and higher ReHo at the right cerebral white matter in the PHIV patients. Although neuroinflammation and associated neuro repair were not directly measured, the findings support their potential role in PHIV impacting neurodevelopment and cognition.

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.

Cognition, Structural Brain Changes, and Systemic Inflammation in Adolescents Living With HIV on Antiretroviral Therapy

OBJECTIVE

To investigate the association between neurocognitive impairment, neuroimaging, and systemic inflammation in perinatally infected adolescents living with HIV (PHIV) on antiretroviral therapy (ART). Systemic inflammation may be one mechanism driving neurocognitive impairment despite ART, but this has not been investigated in adolescence when the brain is undergoing rapid development.

SETTING

Cape Town, South Africa.

METHODS

Baseline data were drawn from the Cape Town Adolescent Antiretroviral Cohort. PHIV on ART >6 months completed a comprehensive neurocognitive test battery. Diffusion tensor imaging and structural brain magnetic resonance imaging was done to determine whole brain fractional anisotropy, mean diffusion (MD), grey and white matter volumes, and cortical thickness. We examined how neurocognitive and neurostructural measures were associated with a concurrently measured marker of systemic inflammation, high-sensitive C-reactive protein (hs-CRP).

RESULTS

One hundred sixty-eight PHIV ages 9-12 years (mean CD4 980 cells/µL; 85.3% viral load <50 copies/mL) and 43 controls were included in the analysis. PHIV had similar hs-CRP (P = 0.17) to controls, after participants with hs-CRP >10 were excluded from the analysis. Forty-eight percent of the PHIV in this analysis have a neurocognitive disorder. Whole brain grey (P = 0.049) and white matter volumes (P = 0.044) were lowest in PHIV with a major neurocognitive disorder. Higher MD, was found in PHIV with a major neurocognitive disorder (P = 0.002). Among PHIV with a neurocognitive disorder, hs-CRP negatively correlated with general intelligence, visual spatial acuity, and executive function (all P = < 0.05). Whole brain MD correlated with higher hs-CRP values (P = < 0.01) in PHIV.

CONCLUSIONS

A marker of systemic inflammation was associated with both neurocognitive impairment and MD increases in PHIV.

Cerebrovascular Disease in Children Perinatally Infected With Human Immunodeficiency Virus in Zambia

BACKGROUND

High rates of cerebrovascular disease (CVD) have previously been described in pediatric human immunodeficiency virus (HIV). However, little is known about pediatric CVD in the era of antiretroviral therapy or about the contribution of CVD to HIV-associated neurocognitive disorders.

METHODS

We completed a neuroimaging substudy of the HIV-Associated Neurocognitive Disorders in Zambia study, a prospective cohort study of neurocognitive complications of pediatric HIV. Brain magnetic resonance imaging (1.5 T) was acquired for 34 HIV+ children on antiretroviral therapy and 17 HIV-exposed uninfected children (aged eight to 17 years). Demographics, medical history, neurological examination, and neuropsychologic testing results were collected. Two neuroradiologists, unaware of HIV status and clinical course, read the scans.

RESULTS

CVD was identified in seven of 34 children with HIV (HIV+ CVD+) and no HIV-exposed uninfected children (21% vs 0%, P = 0.05). Three participants had white matter changes suggestive of small vessel disease, four had infarcts, and two had evidence of intracranial artery stenosis. Age of antiretroviral therapy initiation and exposure to protease inhibitors or efavirenz was not significantly different between children with and without CVD. HIV+ CVD+ children had significantly worse scores on a summary measure of cognition than the HIV+ CVD- group (NPZ8 score -0.57 vs 0.33, P = 0.04).

CONCLUSIONS

This study demonstrates high rates of CVD in children with HIV despite antiretroviral therapy, and worse cognitive performance in children with CVD. Longitudinal studies are necessary to determine the mechanisms and incidence of new-onset CVD in children with HIV.

Differences in location of cerebral white matter hyperintensities in children and adults living with a treated HIV infection: A retrospective cohort comparison

Cerebral white matter hyperintensities (WMH) persist in children and adults living with HIV, despite effective combination antiretroviral therapy (cART). As age and principal routes of transmission differ between children (perinatally) and adults (behaviorally), comparing the characteristics and determinants of WMH between these populations may increase our understanding of the pathophysiology of WMH. From separate cohorts of 31 children (NOVICE) and 74 adults (AGEhIV), we cross-sectionally assessed total WMH volume and number of WMH per location (periventricular vs. deep) using fluid-attenuated inversion recovery (FLAIR) MRI images. WMH were either periventricular when within 10mm of the lateral ventricles, or deep otherwise. We assessed patient- or HIV-related determinants of total WMH volume (adjusted for intracranial volume) and location of WMH using logistic regression, while stratifying on children and adults. At enrollment, median age of participants was 13.8 years (IQR 11.4-15.9) for children and 53.4 years (IQR 48.3-60.8) for adults and 27/31 children (87%) and 74/74 adults (100%) had an HIV RNA viral load <200 copies/mL. WMH were present in 16/27 (52%) children and 74/74 adults (100%). The prevalence of deep WMH was not different between groups, (16/16 [100%] in children vs. 71/74 [96%] in adults, p = 0,999), yet periventricular WMH were more prevalent in adults (74/74 [100%]) compared to children (9/16; 56%) (p<0.001). Median WMH volume was higher in adults compared to children (1182 mm3 [425-2617] vs. 109 mm3 [61.7-625], p<0.001). In children, boys were more likely to have deep WMH compared to girls. In adults, older age was associated with higher total WMH volume, and age, hypertension and lower CD4+ T-lymphocyte nadir with a higher number of periventricular WMH. Our findings suggest that the location of WMH differs between children and adults living with HIV, hinting at a different underlying pathogenesis.

State of the Mind: Growing up with HIV

Human immunodeficiency virus (HIV) is a neurotropic virus that has a detrimental impact on the developing central nervous system (CNS) of children growing up with perinatal HIV (PHIV) due to a combination of pathophysiological processes related to direct viral cytopathic effects and immune activation. This leads to a spectrum of neurocognitive impairment ranging from severe encephalopathy to subtle domain-specific cognitive impairments, as well as psychological disorders that are compounded by HIV-related stigma and sociodemographic factors that disproportionately affect PHIV children. Early commencement and consistent use of combination antiretroviral therapy (cART) has resulted in a dramatic improvement in neuropsychological outcomes for PHIV children; however, they remain vulnerable to cognitive impairment and psychological disorders, as evidenced by imaging findings, randomised clinical trials and observational studies. An optimal neuroprotective cART regimen remains elusive in children, but systemic viral suppression, regular neurocognitive and psychological screening and ready access to neuropsychological management strategies are key components for optimising neuropsychological outcomes. However, a lack of standardised and validated screening tools, particularly in resource-limited settings, hinders a precise understanding of the nature, prevalence and associations between neuropsychological symptomatology and HIV health. This article reviews the natural history, cellular pathophysiology and structural and functional imaging findings for children growing up with HIV, as well as summarising management strategies related to antiretroviral therapy, screening tools and specific interventions for neurocognitive impairments and psychological disorders.

Diffusion tensor imaging point to ongoing functional impairment in HIV-infected children at age 5, undetectable using standard neurodevelopmental assessments

Background

Perinatal HIV infection negatively impacts cognitive functioning of children, main domains affected are working memory, processing speed and executive function. Early ART, even when interrupted, improves neurodevelopmental outcomes. Diffusion tension imaging (DTI) is a sensitive tool assessing white matter damage. We hypothesised that white matter measures in regions showing HIV-related alterations will be associated with lower neurodevelopmental scores in specific domains related to the functionality of the affected tracts.

Methods

DTI was performed on children in a neurodevelopmental sub study from the Children with HIV Early Antiretroviral (CHER) trial. Voxel-based group comparisons to determine regions where fractional anisotropy and mean diffusion differed between HIV+ and uninfected children were done. Locations of clusters showing group differences were identified using the Harvard–Oxford cortical and subcortical and John Hopkins University WM tractography atlases provided in FSL. This is a second review of DTI data in this cohort, which was reported in a previous study. Neurodevelopmental assessments including GMDS and Beery-Buktenica tests were performed and correlated with DTI parameters in abnormal white matter.

Results

38 HIV+ children (14 male, mean age 64.7 months) and 11 controls (4 male, mean age 67.7 months) were imaged. Two clusters with lower fractional anisotropy and 7 clusters with increased mean diffusion were identified in the HIV+ group. The only neurodevelopmental domain with a trend of difference between the HIV+ children and controls (p = 0.08), was Personal Social Quotient which correlated to improved myelination of the forceps minor in the control group. As a combined group there was a negative correlation between visual perception and radial diffusion in the right superior longitudinal fasciculus and left inferior longitudinal fasciculus, which may be related to the fact that these tracts, forming part of the visual perception pathway, are at a crucial state of development at age 5.

Conclusion

Even directed neurodevelopmental tests will underestimate the degree of microstructural white matter damage detected by DTI. The visual perception deficit detected in the entire study population should be further examined in a larger study.

Brain morphometric differences in youth with and without perinatally-acquired HIV: A cross-sectional study

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We performed vertex-wise analyses comparing grey matter in youth with and without perinatally-acquired HIV (PHIV).

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PHIV youth had reduced cortical thickness, surface area, and gyrification compared to control youth.

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PHIV youth did not exhibit the same pattern of inverse grey matter-age relationships that were observed in control youth.

Youth with perinatally-acquired HIV (PHIV) experience specific and global cognitive deficits at increased rates compared to typically-developing HIV-uninfected youth. In youth with PHIV, HIV infects the brain early in development. Neuroimaging studies have demonstrated altered grey matter morphometry in youth with PHIV compared to typically-developing youth. This study examined cortical thickness, surface area, and gyrification of grey matter in youth (age 11–20 years old) with PHIV (n = 40) from the Pediatric HIV/AIDS Cohort Study (PHACS) compared to typically-developing presumed HIV uninfected and unexposed youth (n = 80) from the Pediatric Imaging, Neurocognition and Genetics Study (PING) using structural magnetic resonance imaging. This study also examined the relationship between grey matter morphometry and age. Youth with PHIV had reduced cortical thickness, surface area, and gyrification compared to typically-developing youth. In addition, an inverse relationship between age and grey matter volume was found in typically-developing youth, but was not observed in youth with PHIV. Longitudinal studies are necessary to understand the neurodevelopmental trajectory of youth with PHIV.

Brain microstructural changes support cognitive deficits in HIV uninfected children born to HIV infected mothers

Introduction

Antiretroviral therapy (ART) is considered the most effective way to prevent perinatal transmission of human immunodeficiency virus (HIV). However, there is little knowledge about the effect of ART on the brain of HIV uninfected children born to HIV infected mothers (HUC). The current study evaluated the brain's microstructural integrity, and cognitive function in HUC compared to healthy children born to normal mothers (CHNM) and HIV infected children born to HIV infected mothers (HIC) to investigate the effect of in-utero exposure of ART on cerebral gray and white matter.

Materials and methods

Forty nine HIC, 12 HUC and 18 CHNM underwent neuropsychological (NP) assessment and a brain MRI. Diffusion tensor imaging (DTI) data was used to generate fractional anisotropy (FA) and mean diffusivity (MD) maps. Voxel wise comparison for FA and MD was performed between three groups using an analysis of covariance (ANCOVA) including age and sex as covariates, and correction for multiple comparisons (false discovery rate (FDR), p ​< ​0.05 with minimum extended cluster size, 150 voxels). NP test scores were also compared between three groups using ANOVA with Post Hoc Bonferroni multiple comparison corrections (p ​< ​0.05). Significantly changed FA and MD values in different brain regions in HIC and HUC compared to CHNM were used for correlation analysis with NP test scores using Pearson's correlation.

Results

HIC and HUC groups showed significantly decreased NP test scores in various domain compared to CHNM. Significantly lower NP test scores was observed in HIC than those of HUC. HIC showed decreased FA and increased MD in multiple brain sites as compared to both CHNM and HUC. Decreased FA along with both increased and decreased MD in different brain regions was present in HUC compared to CHNM. Both positive and negative correlation of altered FA and MD values from different brain regions in HIC and HUC with NP test scores was observed.

Conclusion

The presence of brain tissue changes and neurocognitive function deficit in absence of HIV infection in HUC indicates that ART may have a detrimental impact on the developing brain. The findings of the current study underscore the need for screening of ART exposed children for neurodevelopment and cognitive abnormalities at an early stage and call for access to early interventions, and nutritional and care programs.

Maternal infections

Congenital infections are infections transmitted from mother to child during pregnancy (transplacentally) or delivery (peripartum). They have the potential to adversely affect fetal development and long-term neurodevelopmental outcome through inflammatory, destructive, developmental, or teratogenic lesions of the brain. Because the fetal/neonatal brain has a limited capacity to respond to injury, early inflammatory changes may be difficult to visualize and only manifest as neurocognitive disability later in life. Teratogenic effects, which may include aberrations of neuronal proliferation and migration, are more easily visible on imaging, but may be equally difficult to use to predict long-term neurocognitive outcomes. This chapter reviews the general pathophysiology of congenital infection and describes the epidemiology, the antenatal and postnatal diagnosis, and the treatment of congenital infections as well as the long-term neurodevelopmental outcomes.

Brain Magnetic Resonance Imaging Findings Associated With Cognitive Impairment in Children and Adolescents With Human Immunodeficiency Virus in Zambia

BACKGROUND

Cognitive impairment is common in children and adolescents with human immunodeficiency virus (HIV). Brain magnetic resonance imaging (MRI) is a potentially useful tool to investigate the pathophysiology of HIV-associated cognitive impairment and may serve as a biomarker in future clinical trials. There are few published data on brain imaging in children with HIV in sub-Saharan Africa.

METHODS

Thirty-four perinatally infected subjects with HIV and age-matched HIV-exposed uninfected controls between the ages nine and 17 years were recruited from the Pediatric Center of Excellence in Lusaka, Zambia, as part of the HIV-associated Neurocognitive Disorders in Zambia study. Brain MRI sequences were acquired, and clinical and volumetric assessments were performed. Subjects underwent a comprehensive neuropsychologic battery, and cognitive impairment status was classified using a global deficit score approach. Regression models were used to evaluate relationships between MRI findings and cognitive function.

RESULTS

We identified cerebrovascular disease in seven of 34 subjects with HIV compared with zero of 17 controls (21% vs 0%, P = 0.04). We also identified decreased total brain volumes (1036 vs 1162 cm³, P = 0.03) and decreased cortical thickness in the right temporal lobes (3.12 vs 3.29 mm; P = 0.01) and right fusiform gyri (3.10 vs 3.25 mm; P = 0.02) of HIV-infected subjects with cognitive impairment.

CONCLUSIONS

These findings support the hypothesis that brain volumes may be useful biomarkers for cognitive outcomes in children with HIV. Further studies are necessary to investigate mechanisms of cerebrovascular disease and volume loss in children with HIV.

Lower IQ and poorer cognitive profiles in treated perinatally HIV-infected children is irrespective of having a background of international adoption

Background

HIV-associated cognitive deficiency in perinatally HIV-infected (PHIV) children has been studied in Western countries in a population of which an increasing proportion has been internationally adopted. Studies often lack an appropriate internationally adopted HIV-uninfected control group, potentially confounding the relationship between HIV and cognitive functioning. This study aims to further elucidate the association between treated HIV infection and cognitive development by addressing the background of international adoption.

Methods

We cross-sectionally studied the impact of HIV on cognition by comparing PHIV children and HIV- uninfected controls, matched for age-, sex-, ethnicity-, socioeconomic status (SES)- and adoption status. We used a standardized neuropsychological test battery to measure intelligence (IQ), and the cognitive domains of processing speed, working memory, executive function, learning ability and visual-motor function and compared outcomes using lineair regression models, adjusted for IQ. We determined cognitive profiles and cognitive impairment by using multivariate normative comparison (MNC) and explored associations with HIV disease- and treatment-related factors.

Results

We enrolled fourteen PHIV children (mean age 10.45 years [1.73 SD], 93% adopted from sub-Saharan Africa at a median age of 3.3 years [IQR 2.1–4.2]) and fifteen HIV- uninfected controls. Groups did not clinically nor statistically differ in age, sex, ethnicity, SES, region of birth, adoption status and age at adoption. PHIV scored consistently lower on all cognitive domains and MNC outcomes. Compared to controls, PHIV children had a significant lower IQ (mean 81 [SD 11] versus mean 97 [SD 15], p = 0.005), and a poorer cognitive profile by MNC (Hotelling’s T² mean -4.36 [SD 5.6] versus mean 0.16 [SD 4.5], p = 0.021), not associated with HIV disease- and treatment-related factors. Two PHIV (14%) and one control (7%) were classified as cognitively impaired (p = 0.598).

Conclusions

Findings indicate treated HIV-infection to be independently associated with lower IQ and poorer cognitive profiles in PHIV children, irrespective of a background of international adoption.

Elevated Lipoprotein(a) in Perinatally HIV-Infected Children Compared With Healthy Ethnicity-Matched Controls

Background

HIV-associated cardiovascular disease (CVD) risk in combination antiretroviral therapy (cART)-treated perinatally HIV-infected patients (PHIV+) remains unknown due to the young age of this population. Lipoprotein(a) (Lp(a)) has been established as an independent causal risk factor for CVD in the general population but has not been well established in the population of PHIV+.

Methods

We cross-sectionally compared lipid profiles, including nonfasting Lp(a), together with total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides between 35 cART-treated PHIV+ children aged 8-18 years and 37 controls who were matched for age, sex, ethnicity, and socioeconomic status. We explored associations between Lp(a) and disease- and treatment-related factors (inflammation, monocyte activation, and vascular), biomarkers, and neuroimaging outcomes using linear regression models.

Results

PHIV+ children had significantly higher levels of Lp(a) compared with controls (median, 43.6 [21.6-82.4] vs 21.8 [16.8-46.6] mg/dL; P = .033). Other lipid levels were comparable between groups. Additional assessment of apolipoprotein B, apolipoprotein CIII, apolipoprotein E, and APOE genotype revealed no significant differences. Higher Lp(a) levels were associated with higher plasma apoB levels and with lower monocyte chemoattractant protein-1 and TG levels in PHIV+ children. Lp(a) was not associated with HIV- or cART-related variables or with neuroimaging outcomes.

Conclusions

cART-treated PHIV+ children appear to have higher levels of Lp(a) compared with ethnicity-matched controls, which may implicate higher CVD risk in this population. Future research should focus on the association between Lp(a) and (sub)clinical CVD measurements in cART-treated PHIV+ patients.

Dutch Trial Register number

NRT4074.

HIV-infected youths transitioning from pediatric to adult outpatient care in a teaching tertiary care hospital in São Paulo city, Brazil

Background

HIV-infected children surviving until adulthood have been transitioning to adult outpatient health care service in Brazil since the late 2000's. Deterioration of clinical condition is expected during this period, as reported among youths with non-communicable chronic diseases. Despite their young age, they are long-term hosts of the virus, have prolonged exposure to antiretroviral therapy and have suffered from the social determinants and stigma of HIV infection since early childhood.

Objectives

This study aimed to 1) describe demographic and clinical characteristics at the first appointment at adult care service following pediatric care of a cohort of Brazilian youths living with HIV since childhood; and 2) retrospectively address adherence and clinical variables in the last two years of pediatric follow-up.

Methods

Descriptive study.

Results

41 consecutive patients referred to adult outpatient care from a pediatric HIV unit were enrolled, median age 19 years, and median lifetime CD4 + nadir 117 cell/mm³; 89% reported previous AIDS-defining conditions. At first laboratory assessment in adult care, only 46% had undetectable (<400 copies/ml) HIV viral load and the median CD4 + count was 250 cell/mm³.

Conclusion

Youths living with HIV at the transition from pediatric to adult care had poor treatment adherence, low lifetime CD4 + cell nadir, low CD4 cell count and detectable HIV viral load. Health care providers should closely monitor these adolescents in a youth friendly environment, prepared for open communication about all aspects of their health.

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.

Human immunodeficiency virus-related cerebral white matter disease in children

The human immunodeficiency virus (HIV) epidemic seems largely controlled by anti-retroviral treatment with resultant large numbers of children growing up with the disease on long-term treatment, placing them at higher risk to develop HIV-related brain injury, ongoing cognitive impairment and treatment-related neurological complications. Cerebral white matter involvement is a common radiologic finding in HIV infection and the causes of this have overlapping appearances, ranging from diffuse widespread involvement to focal lesions. The varied pathophysiology is broadly grouped into primary effects of HIV, opportunistic infection, vascular disease and neoplasms. White matter changes in children can be different from those in adults. This review provides guidance to radiologists with the diagnostic dilemma of nonspecific cerebral white matter lesions in children with HIV. The authors discuss common causes of HIV-related cerebral white matter disease as well as the role of neuroimaging in the management of these children.

Brain structure of perinatally HIV-infected patients on long-term treatment: A systematic review

Objective

We aim to give an overview of the available evidence on brain structure and function in PHIV-infected patients (PHIV+) using long-term combination antiretroviral therapy (cART) and how differences change over time.

Methods

We conducted an electronic search using MEDLINE, Embase, and PsycINFO. We used the following selection criteria: cohort and cross-sectional studies that reported on brain imaging differences between PHIV+ of all ages who used cART for at least six months before neuroimaging and HIV-negative controls. Two reviewers independently selected studies, performed data extraction, and assessed quality of studies.

Results

After screening 1500 abstracts and 343 full-text articles, we identified 19 eligible articles. All included studies had a cross-sectional design and used MRI with different modalities: structural MRI (n = 7), diffusion tensor imaging (DTI) (n = 6), magnetic resonance spectroscopy (n = 5), arterial spin labeling (n = 1), and resting-state functional neuroimaging (n = 1). Studies showed considerable methodological limitations and heterogeneity, preventing us to perform meta-analyses. DTI data on white matter microstructure suggested poorer directional diffusion in cART-treated PHIV+ compared with controls. Other modalities were inconclusive.

Conclusion

Evidence may suggest brain structure and function differences in the population of PHIV+ on long-term cART compared with the HIV-negative population. Because of a small study population, and considerable heterogeneity and methodological limitations, the extent of brain structure and function differences on neuroimaging between groups remains unknown.

Mapping abnormal subcortical neurodevelopment in a cohort of Thai children with HIV

Alterations in subcortical brain structures have been reported in adults with HIV and, to a lesser extent, pediatric cohorts. The extent of longitudinal structural abnormalities in children with perinatal HIV infection (PaHIV) remains unclear. We modeled subcortical morphometry from whole brain structural magnetic resonance imaging (1.5 T) scans of 43 Thai children with PaHIV (baseline age = 11.09±2.36 years) and 50 HIV- children (11.26±2.80 years) using volumetric and surface-based shape analyses. The PaHIV sample were randomized to initiate combination antiretroviral treatment (cART) when CD4 counts were 15-24% (immediate: n = 22) or when CD4 < 15% (deferred: n = 21). Follow-up scans were acquired approximately 52 weeks after baseline. Volumetric and shape descriptors capturing local thickness and surface area dilation were defined for the bilateral accumbens, amygdala, putamen, pallidum, thalamus, caudate, and hippocampus. Regression models adjusting for clinical and demographic variables examined between and within group differences in morphometry associated with HIV. We assessed whether baseline CD4 count and cART status or timing associated with brain maturation within the PaHIV group. All models were adjusted for multiple comparisons using the false discovery rate. A pallidal subregion was significantly thinner in children with PaHIV. Regional thickness, surface area, and volume of the pallidum was associated with CD4 count in children with PaHIV. Longitudinal morphometry was not associated with HIV or cART status or timing, however, the trajectory of the left pallidum volume was positively associated with baseline CD4 count. Our findings corroborate reports in adult cohorts demonstrating a high predilection for HIV-mediated abnormalities in the basal ganglia, but suggest the effect of stable PaHIV infection on morphological aspects of brain development may be subtle.

CNS penetration of ART in HIV-infected children

Background

Paediatric data on CNS penetration of antiretroviral drugs are scarce.

Objectives

To evaluate CNS penetration of antiretroviral drugs in HIV-infected children and explore associations with neurocognitive function.

Patients and methods

Antiretroviral drug levels were measured in paired CSF and blood samples of clinically stable HIV-infected children between 8 and 18 years old on long-term combined ART. Plasma drug concentrations were corrected for protein binding. We evaluated CNS penetration using CSF/plasma ratios and compared CSF concentrations with the IC50 as a surrogate marker for effectiveness. Blood-brain barrier permeability was assessed for possible confounding. Associations with neurocognitive function were explored using linear regression analysis.

Results

Median CSF/plasma ratios (IQR) were: lopinavir 0.059 (0.024-0.157, n = 7), efavirenz 0.681 (0.555-0.819, n = 12), tenofovir 0.021 (0.020-0.024, n = 4), lamivudine 0.464 (0.331-0.607, n = 17), emtricitabine 0.365 (0.343-0.435, n = 3), nevirapine 1.203 (n = 1), zidovudine 0.718 (0.711-1.227, n = 5) and abacavir 1.344 (0.670-2.450, n = 10). CSF concentrations were below the IC50 for tenofovir (100%), emtricitabine (100%), abacavir (50%) and zidovudine (17%). Lamivudine, lopinavir, efavirenz and nevirapine concentrations were all above the IC50. All participants were virologically suppressed in blood and CSF. CSF drug concentrations were not associated with blood-brain barrier permeability or neurocognitive function.

Conclusions

We showed adequate CSF concentrations of lamivudine, lopinavir, efavirenz and nevirapine, and potential suboptimal CSF concentrations of tenofovir, abacavir and emtricitabine in long-term treated HIV-infected children. None the less, the use of combined antiretroviral drugs led to adequate viral suppression.

Initiation of antiretroviral therapy after the critical neuronal developmental period of the second postnatal year affects white matter microstructure in adolescents living with HIV

Rapid maturation of major white matter pathways occurs in the first 2 years of life, indicating a critical neuronal developmental period. The impact of initiating antiretroviral therapy (ART) in children perinatally infected with HIV-1, after the age of 2 years on neurocognitive functioning and white matter development in adolescence has not been studied. Forty-six adolescents who initiated ART during the first 2 years of life (< 2 years) and 79 adolescents who initiated ART after 2 years of age (> 2 years), with perinatally acquired HIV were enrolled in the Cape Town Adolescent Antiretroviral Cohort. Adolescents completed a comprehensive neurocognitive battery testing a number of cognitive domains. Diffusion tensor imaging (DTI) was done to determine fractional anisotropy (FA), mean diffusivity (MD), axial diffusion (AD), and radial diffusion (RD) in a region of interest analysis. Neurocognitive performance was similar between adolescents who initiated ART < 2 years or > 2 years. There was a trend towards attention (p = .07) and working memory (p = .05) being poorer in the group who initiated ART > 2 years. FA was lower in the > 2-year group in the superior corona radiata (p = .03), and the external capsule (p = .04). MD was higher in the > 2-year group in the cerebral peduncle (p = .02), the superior corona radiata (p = .01), and the superior fronto-occipital fasciculus (p = .03). RD was higher in the > 2-year group in the superior corona radiata (p = .02), the cerebral peduncle (p = .01), and the superior fronto-occipital fasciculus (p = .01). However, the higher AD in the > 2-year group in the superior corona radiata was not in the expected direction (p = .01). Initiation of ART after the neuronal development period of the second postnatal year is associated with white matter alterations on neuroimaging.

White matter microstructure among perinatally HIV-infected youth: a diffusion tensor imaging study

We evaluated white matter microstructure integrity in perinatally HIV-infected (PHIV) youths receiving cART compared to age- and gender-matched healthy youths through DTI metrics using voxel-based morphometry (VBM). We investigated 14 perinatally HIV-infected patients (age 17.9 ± 2.5 years) on cART and 17 healthy youths (HC) (age 18.0 ± 3.0 years) using a 3T MRI scanner. Four DTI-derived metrics were fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD). Statistical analysis was done with voxel-based analysis of covariance (ANCOVA), with age and gender as covariates. Region-of-interest secondary analyses in statistically significant regions were also performed. Regional increases in FA in the PHIV youths were found in left middle frontal gyrus, right precuneus, right lingual gyrus, and left supramarginal gyrus. Increased MD was found in the right precentral gyrus while decreased MD was found in the white matter of the right superior parietal lobule and right inferior temporal gyrus/fusiform gyrus. Regions of increased/decreased RD overlapped with regions of increased/decreased MD. Both increased and decreased AD were found in three to four regions respectively. The regional FA, MD, RD, and AD values were consistent with the voxel-based analysis findings. The findings are mostly consistent with previous literature, but increased FA has not been previously reported for perinatally HIV-infected youths. Potentially early and prolonged therapy in our population may have contributed to this new finding. Both toxicity of antiretroviral therapy and indolent infection must be considered as causative factors in the DTI metric changes that we have observed.

Structural brain changes in perinatally HIV-infected young adolescents in South Africa

OBJECTIVE

To describe the structural brain changes, neurocognitive and mental health associations in adolescents perinatally infected with HIV-1 infection.

DESIGN

Cross-sectional.

METHODS

Two hundred and four adolescents with perinatally acquired HIV and 44 uninfected frequency-matched controls aged 9-11 years were enrolled within the Cape Town Adolescent Antiretroviral Cohort. Diffusion tensor imaging and structural brain MRI was done to determine fractional anisotropy, mean diffusivity, grey and white matter volumes, cortical thickness and cortical surfractional anisotropy area. Correlation coefficients were calculated between total grey and white matter volume, cortical surface area, cortical thickness, whole brain fractional anisotropy and whole brain mean diffusivity and clinical and laboratory parameters including general intellectual functioning, Becks Youth Inventory, Child Motivation Scale and Child Behaviour Checklist.

RESULTS

HIV-infected adolescents performed worse than controls on the Wechsler Abbreviated Scale of Intelligence (WASI; P < 0.01). HIV-infected adolescents had significant fractional anisotropy decreases, mean diffusivity increases and decreases in cerebral grey matter volumes, cortical surface area and decreased gyrification. Whole-brain mean fractional anisotropy was significantly reduced in the HIV-infected group (P = 0.031). There were significant correlation coefficients between greater total grey (P = 0.008) and white matter volume (P = 0.004) with the WASI and the Becks self-concept subscale (P = 0.038). Lower whole brain fractional anisotropy was associated with higher scores on the Becks anger (P = 0.018) and disruptive behaviour subscales (P = 0.031). Higher whole brain mean diffusivity was associated with apathy (P = 0.046).

CONCLUSION

The pattern of increased risk of white matter microstructure alterations, smaller grey matter volumes, reduced cortical surface area and decreased gyrification, suggests abnormal neurodevelopment in perinatally infected younger adolescents.

Changes in resting-state functional brain activity are associated with waning cognitive functions in HIV-infected children

Delayed brain development in perinatally HIV-infected children may affect the functional brain activity and subsequently cognitive function. The current study evaluated the functional brain activity in HIV-infected children by quantifying the amplitude of low frequency fluctuations (ALFF) and functional connectivity (FC). Additionally, correlation of ALFF and FC with cognitive measures was performed. Twenty-six HIV-infected children and 20 control children underwent neuropsychological (NP) assessment and resting-state functional magnetic resonance imaging (rs-fMRI). ALFF and FC maps were generated and group differences were analyzed using two-sample t-test. Furthermore, ALFF and FC showing significant group differences were correlated with NP scores using Pearson's correlation. Significantly lower ALFF in the left middle temporal gyrus, precentral and post central gyrus was observed in HIV-infected children compared to controls. FC was significantly reduced in the right inferior parietal, vermis, middle temporal and left postcentral regions, and significantly increased in the right precuneus, superior parietal and left middle frontal regions in HIV-infected children as compared to control. HIV-infected children showed significantly lower NP scores in various domains including closure, exclusion, memory, verbal meaning, quantity and hidden figure than controls. These waning cognitive functions were significantly associated with changes in ALFF and FC in HIV-infected children. The findings suggest that abnormal ALFF and FC may responsible for cognitive deficits in HIV-infected children. ALFF and FC in association with cognitive evaluation may provide a clinical biomarker to evaluate functional brain activity and to plan neurocognitive intervention in HIV-infected children undergoing standard treatment.

HIV disease and diabetes interact to affect brain white matter hyperintensities and cognition

BACKGROUND

Since the onset of combination antiretroviral therapy use, the incidence of HIV-associated dementia and of HIV encephalitis has fallen dramatically. The present study investigates the extent of white matter hyperintensities (WMHs) among individuals with HIV disease, and factors that predict their presence and their impact on psychomotor speed.

METHODS

A total of 322 men participating in the Multicenter AIDS Cohort Study (185 HIV-infected, age: 57.5 ± 6.0) underwent MRI scans of the brain. T1-weighted magnetization-prepared rapid gradient-echo (MP-RAGE) and T2-weighted Fluid Attenuated Inversion Recovery (FLAIR) images were obtained and processed using an automated method for identifying and measuring WMHs. WMH burden was expressed as the log10 transformed percentage of total white matter.

RESULTS

There were no significant associations between WMHs and HIV disease. However, the extent of WMHs was predicted by age more than 60 (β = 0.17), non-white race (β = 0.14), glomerular filtration rate (β = -0.11), and the presence of diabetes (β = 0.12). There were no interactions between HIV status and age (β = -0.03) or between age and diabetes (β = 0.07). However, the interaction between HIV infection and diabetes was significant (β = 0.26). The extent of WMHs was significantly associated with performance on measures of psychomotor speed (β = 0.15).

CONCLUSION

In today's therapeutic environment, in HIV-infected and HIV seronegative individuals, those factors which affect the cerebrovasculature are the best predictors of WMHs. Diabetes has a specific impact among HIV-infected, but not uninfected, men, suggesting the need for more aggressive treatment even in the prediabetes state, especially as WMHs affect cognitive functions.

Structural Neuroimaging and Neuropsychologic Signatures in Children With Vertically Acquired HIV

BACKGROUND

Children with vertically acquired HIV exhibit persistent cognitive impairments, yet the corresponding neuroimaging signature of vertical infection remains unclear.

METHODS

Fifty healthy control children and 51 vertically infected children were included in the study. The HIV-infected group consisted of survivors who had not received antiretroviral therapy at birth. The HIV-infected group averaged 11.4 (2.5) years of age, with a median CD4 count of 683 cells/mm(3). Most (71%) of the HIV-infected children were on antiretroviral therapy for a median of 34 months (range: 33-42) with HIV RNA <40 copies/mL in 89% of the sample. The HIV-uninfected group averaged 10.6 (2.6) years of age. Magnetic resonance imaging was acquired to determine volumes of the caudate, putamen, thalamus, pallidum, hippocampus, nucleus accumbens, total white matter, total gray matter and cortical gray matter. Correlational analyses examined the degree of shared variance between brain volumes and both cognitive performances and laboratory markers of disease activity (T cells and plasma viral load).

RESULTS

HIV-infected children exhibited larger volumes of the caudate, nucleus accumbens, total gray matter and cortical gray matter when compared with the controls. Volumetric differences were predominately evident in children under 12 years of age. HIV-infected children performed worse than controls on most neuropsychologic tests, though neither cognitive performances nor laboratory markers corresponded to brain volumes in the HIV-infected children.

CONCLUSIONS

Outcomes of the present study suggest abnormal brain maturation among HIV-infected pediatric survivors. Longitudinal studies of brain integrity and related resilience factors are needed to determine the impact of neuroimaging abnormalities on psychosocial function in pediatric HIV.

Dose-dependent neurocognitive deficits following postnatal day 10 HIV-1 viral protein exposure: Relationship to hippocampal anatomy parameters

Despite the availability of antiretroviral prophylactic treatment, pediatric human immunodeficiency virus type 1 (HIV-1) continues to be a significant risk factor in the post-cART era. The time of infection (i.e., during pregnancy, delivery or breastfeeding) may play a role in the development of neurocognitive deficits in pediatric HIV-1. HIV-1 viral protein exposure on postnatal day (P)1, preceding the postnatal brain growth spurt in rats, had deleterious effects on neurocognitive development and anatomical parameters of the hippocampus (Fitting et al., 2008a,b). In the present study, rats were stereotaxically injected with HIV-1 viral proteins, including Tat1-86 and gp120, on P10 to further examine the role of timing on neurocognitive development and anatomical parameters of the hippocampus (Fitting et al., 2010). The dose-dependent virotoxin effects observed across development following P10 Tat1-86 exposure were specific to spatial learning and absent from prepulse inhibition and locomotor activity. A relationship between alterations in spatial learning and/or memory and hippocampal anatomical parameters was noted. Specifically, the estimated number of neurons and astrocytes in the hilus of the dentate gyrus explained 70% of the variance of search behavior in Morris water maze acquisition training for adolescents and 65% of the variance for adults; a brain-behavior relationship consistent with observations following P1 viral protein exposure. Collectively, late viral protein exposure (P10) results in selective alterations in neurocognitive development without modifying measures of somatic growth, preattentive processing, or locomotor activity, as characterized by early viral protein exposure (P1). Thus, timing may be a critical factor in disease progression, with children infected with HIV earlier in life being more vulnerable to CNS disease.

Altered brain morphometry in 7-year old HIV-infected children on early ART

Even with the increased roll out of combination antiretroviral therapy (cART), paediatric HIV infection is associated with neurodevelopmental delays and neurocognitive deficits that may be accompanied by alterations in brain structure. Few neuroimaging studies have been done in children initiating ART before 2 years of age, and even fewer in children within the critical stage of brain development between 5 and 11 years. We hypothesized that early ART would limit HIV-related brain morphometric deficits at age 7. Study participants were 7-year old HIV-infected (HIV+) children from the Children with HIV Early Antiretroviral Therapy (CHER) trial whose viral loads were supressed at a young age, and age-matched uninfected controls. We used structural magnetic resonance imaging (MRI) and FreeSurfer ( http://www.freesurfer.net/ ) software to investigate effects of HIV and age at ART initiation on cortical thickness, gyrification and regional brain volumes. HIV+ children showed reduced gyrification compared to controls in bilateral medial parietal regions, as well as reduced volumes of the right putamen, left hippocampus, and global white and gray matter and thicker cortex in small lateral occipital region. Earlier ART initiation was associated with lower gyrification and thicker cortex in medial frontal regions. Although early ART appears to preserve cortical thickness and volumes of certain brain structures, HIV infection is nevertheless associated with reduced gyrification in the parietal cortex, and lower putamen and hippocampus volumes. Our results indicate that in early childhood gyrification is more sensitive than cortical thickness to timing of ART initiation. Future work will clarify the implications of these morphometric effects for neuropsychological function.

Structural Covariance of Gray Matter Volume in HIV Vertically Infected Adolescents

Human immunodeficiency virus (HIV) infection significantly affect neurodevelopmental and behavioral outcomes. We investigated whether alterations of gray matter organization and structural covariance networks with vertical HIV infection adolescents exist, by using the GAT toolbox. MRI data were analysed from 25 HIV vertically infected adolescents and 33 HIV-exposed-uninfected control participants. The gray matter volume (GMV) was calculated, and structural brain networks were reconstructed from gray matter co-variance. Gray matter losses were pronounced in anterior cingulate cortex (ACC), right pallidum, right occipital lobe, inferior parietal lobe, and bilateral cerebellum crus. The global brain network measures were not significantly different between the groups; however, the nodal alterations were most pronounced in frontal, temporal, basal ganglia, cerebellum, and temporal lobes. Brain hubs in the HIV-infected subjects increased in number and tended to shift to sensorimotor and temporal areas. In the HIV-infected subjects, decreased GMVs in ACC and bilateral cerebellum were related to lower Mini-Mental State Examination scores; the CD4 counts were positively related to the GMVs in ACC and sensorimotor areas. These findings suggest that focally reduced gray matter, disrupted nodal profiles of structural wirings, and a shift in hub distribution may represent neuroanatomical biomarkers of HIV infection on the developing brain.

Functional Connectivity Alterations between Networks and Associations with Infant Immune Health within Networks in HIV Infected Children on Early Treatment: A Study at 7 Years

Although HIV has been shown to impact brain connectivity in adults and youth, it is not yet known to what extent long-term early antiretroviral therapy (ART) may alter these effects, especially during rapid brain development in early childhood. Using both independent component analysis (ICA) and seed-based correlation analysis (SCA), we examine the effects of HIV infection in conjunction with early ART on resting state functional connectivity (FC) in 7 year old children. HIV infected (HIV+) children were from the Children with HIV Early Antiretroviral Therapy (CHER) trial and all initiated ART before 18 months; uninfected children were recruited from an interlinking vaccine trial. To better understand the effects of current and early immune health on the developing brain, we also investigated among HIV+ children the association of FC at 7 years with CD4 count and CD4%, both in infancy (6–8 weeks) and at scan. Although we found no differences within any ICA-generated resting state networks (RSNs) between HIV+ and uninfected children (27 HIV+, 18 uninfected), whole brain connectivity to seeds located at RSN connectivity peaks revealed several loci of FC differences, predominantly from seeds in midline regions (posterior cingulate cortex, paracentral lobule, cuneus, and anterior cingulate). Reduced long-range connectivity and increased short-range connectivity suggest developmental delay. Within the HIV+ children, clinical measures at age 7 years were not associated with FC values in any of the RSNs; however, poor immune health during infancy was associated with localized FC increases in the somatosensory, salience and basal ganglia networks. Together these findings suggest that HIV may affect brain development from its earliest stages and persist into childhood, despite early ART.

Imaging studies of the HIV-infected brain

Human immunodeficiency virus (HIV) enters the brain early after infecting humans and may remain in the central nervous system despite successful antiretroviral treatment. Many neuroimaging techniques were used to study HIV+ patients with or without opportunistic infections. These techniques assessed abnormalities in brain structures (using computed tomography, structural magnetic resonance imaging (MRI), diffusion MRI) and function (using functional MRI at rest or during a task, and perfusion MRI with or without a contrast agent). In addition, single-photon emission computed tomography with various tracers (e.g., thallium-201, Tc99-HMPAO) and positron emission tomography with various agents (e.g., [18F]-dexoyglucose, [11C]-PiB, and [11C]-TSPO tracers), were applied to study opportunistic infections or HIV-associated neurocognitive disorders. Neuroimaging provides diagnoses and biomarkers to quantitate the severity of brain injury or to monitor treatment effects, and may yield insights into the pathophysiology of HIV infection. As the majority of antiretroviral-stable HIV+ patients are living longer, age-related comorbid disorders (e.g., additional neuroinflammation, cerebrovascular disorders, or other dementias) will need to be considered. Other highly prevalent conditions, such as substance use disorders, psychiatric illnesses, and the long-term effects of combined antiretroviral therapy, all may lead to additional brain injury. Neuroimaging studies could provide knowledge regarding how these comorbid conditions impact the HIV-infected brain. Lastly, specific molecular imaging agents may be needed to assess the central nervous system viral reservoir.

Brain Structural Changes following HIV Infection: Meta-Analysis

BACKGROUND

Numerous studies have used structural neuroimaging to measure HIV effects on brain macroarchitecture. While many have reported changes in total brain volume, gray matter volume, white matter volume, CSF volume, and basal ganglia volume following HIV infection, quantitative inconsistencies observed across studies are large.

PURPOSE

Our aim was to evaluate the consistency and temporal stability of serostatus effects on a range of structural neuroimaging measures.

DATA SOURCES

PubMed, reference lists, and corresponding authors.

STUDY SELECTION

The meta-analysis included 19 cross-sectional studies reporting HIV effects on cortical and subcortical volume from 1993 to 2016.

DATA ANALYSIS

Random-effects meta-analysis was used to estimate individual study standardized mean differences and study heterogeneity. Meta-regression was used to examine the effects of the study publication year.

DATA SYNTHESIS

Meta-analysis revealed standardized mean differences related to the serostatus of -0.65 (P = .002) for total brain volume, -0.28 for gray matter volume (P = .008), -0.24 (P = .076) for white matter volume, and 0.56 (P = .001) for CSF volume. Basal ganglia volume differences related to serostatus were not significant. Nevertheless, estimates of between-study heterogeneity suggested that much of the observed variance was between studies. Publication year was associated with recent reductions in many neurostructural effects.

LIMITATIONS

Many studies pooled participants with varying durations of treatment, disease, and comorbidities. Image-acquisition methods changed with time.

CONCLUSIONS

While published studies of HIV effects on brain structure had substantial variations that are likely to result from changes in HIV treatment practice during the study period, quantitative neurostructural measures can reliably detect the effects of HIV infection during treatment, serving as reliable biomarkers.

Larger Subcortical Gray Matter Structures and Smaller Corpora Callosa at Age 5 Years in HIV Infected Children on Early ART

Sub-Saharan Africa is home to 90% of HIV infected (HIV+) children. Since the advent of antiretroviral therapy (ART), HIV/AIDS has transitioned to a chronic condition where central nervous system (CNS) damage may be ongoing. Although, most guidelines recommend early ART to reduce CNS viral reservoirs, the brain may be more vulnerable to potential neurotoxic effects of ART during the rapid development phase in the first years of life. Here we investigate differences in subcortical volumes between 5-year-old HIV+ children who received early ART (before age 18 months) and uninfected children using manual tracing of Magnetic Resonance Images. Participants included 61 Xhosa children (43 HIV+/18 uninfected, mean age = 5.4 ± 0.3 years, 25 male) from the children with HIV early antiretroviral (CHER) trial; 27 children initiated ART before 12 weeks of age (ART-Before12Wks) and 16 after 12 weeks (ART-After12Wks). Structural images were acquired on a 3T Allegra MRI in Cape Town and manually traced using MultiTracer. Volumetric group differences (HIV+ vs. uninfected; ART-Before12Wks vs. ART-After12Wks) were examined for the caudate, nucleus accumbens (NA), putamen (Pu), globus pallidus (GP), and corpus callosum (CC), as well as associations within infected children of structure volumes with age at ART initiation and CD4/CD8 as a proxy for immune health. HIV+ children had significantly larger NA and Pu volumes bilaterally and left GP volumes than controls, whilst CC was smaller. Bilateral Pu was larger in both treatment groups compared to controls, while left GP and bilateral NA were enlarged only in ART-After12Wks children. CC was smaller in both treatment groups compared to controls, and smaller in ART-After12Wks compared to ART-Before12Wks. Within infected children, delayed ART initiation was associated with larger Pu volumes, effects that remained significant when controlling for sex and duration of treatment interruption (left β = 0.447, p = 0.005; right β = 0.325, p = 0.051), and lower CD4/CD8 with larger caudates controlling for sex (left β = -0.471, p = 0.002; right β = -0.440, p = 0.003). Volumetric differences were greater in children who initiated ART after 12 weeks. Results suggest damage is ongoing despite early ART and viral load suppression; however, earlier treatment is neuroprotective.

White Matter Abnormalities in Children with HIV Infection and Exposure

Background: Due to changes in guidelines and access to treatment, more children start combination antiretroviral therapy (ART) in infancy. With few studies examining the long-term effects of perinatal HIV infection and early ART on neurodevelopment, much is still unknown about brain maturation in the presence of HIV and ART. Follow-up studies of HIV infected (HIV+) children are important for monitoring brain development in the presence of HIV infection and ART.

Methods: We use diffusion tensor imaging (DTI) to examine white matter (WM) in 65 HIV+ and 46 control (HIV exposed uninfected (HEU) and HIV unexposed uninfected (HU)) 7-year-old children. This is a follow up of a cohort studied at 5 years, where we previously reported lower fractional anisotropy (FA) in corticospinal tract (CST) and mean diffusivity (MD) increases in inferior/superior longitudinal fasciculi (ILF/SLF), inferior fronto-occipital fasciculus (IFOF) and uncinate fasciculus (UF) in HIV+ children compared to uninfected controls. In addition, we also found a difference in FA related to age at which ART was initiated.

Results: At 7 years, we found two regions in the left IFOF and left ILF with lower FA in HIV+ children compared to controls. Higher MD was observed in a similar region in the IFOF, albeit bilaterally, as well as multiple clusters bilaterally in the superior corona radiata (SCR), the anterior thalamic radiation (ATR) and the right forceps minor. Unlike at 5 years, we found no impact on WM of ART initiation. In HEU children, we found a cluster in the right posterior corona radiata with higher FA compared to HU children, while bilateral regions in the CST demonstrated reduced MD.

Conclusions: At age 7, despite early ART and viral load (VL) suppression, we continue to observe differences in WM integrity. WM damage observed at age 5 years persists, and new damage is evident. The continued observation of regions with lower FA and higher MD in HIV+ children point to disruptions in ongoing white matter development regardless of early ART. Lastly, in HEU children we find higher FA and lower MD in clusters in the CST tract suggesting that perinatal HIV/ART exposure has a long-term impact on WM development.

Neurocognitive development in HIV-positive children is correlated with plasma viral loads in early childhood

Because of neurocognitive impairments in perinatally human immunodeficiency virus (HIV)-infected children and adolescents, this study aimed to demonstrate the effect of plasma viral loads and early initiation of sufficient combined antiretroviral therapy (cART) on neurocognitive development.In total, 14 perinatally infected HIV-positive children (median age 8.24 years [range: 6.0-16.74]) receiving lopinavir/ritonavir (LPV/r)-based ART underwent neurocognitive testing using the Wechsler Intelligence Score for Children, 4th Edition (WISC-IV). All 14 patients participated in a pharmacokinetic study in which they were hospitalized for an entire day. As a child's ability to concentrate varies over the course of the day, all tests were performed in the morning.The patients' neurocognitive development did not significantly differ from the normative collective pattern for any of the following composite scores that were examined: full-scale intelligence quotient (IQ) (mean: 106.5, P = .1060), verbal comprehension index (mean: 106.0, P = .1356), perceptual reasoning index (mean: 106.0, P = .1357), working memory index (mean: 106.3, P = .1171), and processing speed index (mean: 98.1, P = .6313). The overall full-scale IQ scores were significantly higher in children who began ART within the first year of life (P = .0379), whereas low lopinavir/r plasma levels (P = .0070) and high viral load area under the curves (AUCs) in the first 3 years of life, but not later, significantly correlated with reduced neurocognitive performance (Spearman r = -0.64, P = .0278).In this cohort of cART treated HIV-positive children and adolescents, neurocognitive performance correlated with early and sufficient viral load suppression within the first 3 years of life.