Encephalopathy in children with perinatally acquired human immunodeficiency virus infection. Pediatric Spectrum of Disease Clinical Consortium

Similar cortical morphometry trajectories from 5 to 9 years in children with perinatal HIV who started treatment before age 2 years and uninfected controls

BACKGROUND

Life-long early ART (started before age 2 years), often with periods of treatment interruption, is now the standard of care in pediatric HIV infection. Although cross-sectional studies have investigated HIV-related differences in cortical morphology in the setting of early ART and ART interruption, the long-term impact on cortical developmental trajectories is unclear. This study compares the longitudinal trajectories of cortical thickness and folding (gyrification) from age 5 to 9 years in a subset of children perinatally infected with HIV (CPHIV) from the Children with HIV Early antiRetroviral therapy (CHER) trial to age-matched children without HIV infection.

METHODS

75 CHER participants in follow-up care at FAMCRU (Family Centre for Research with Ubuntu), as well as 66 age-matched controls, received magnetic resonance imaging (MRI) on a 3 T Siemens Allegra at ages 5, 7 and/or 9 years. MR images were processed, and cortical surfaces reconstructed using the FreeSurfer longitudinal processing stream. Vertex-wise linear mixed effects (LME) analyses were performed across the whole brain to compare the means and linear rates of change of cortical thickness and gyrification from 5 to 9 years between CPHIV and controls, as well as to examine effects of ART interruption.

RESULTS

Children without HIV demonstrated generalized cortical thinning from 5 to 9 years, with the rate of thinning varying by region, as well as regional age-related gyrification increases. Overall, the means and developmental trajectories of cortical thickness and gyrification were similar in CPHIV. However, at an uncorrected p < 0.005, 6 regions were identified where the cortex of CPHIV was thicker than in uninfected children, namely bilateral insula, left supramarginal, lateral orbitofrontal and superior temporal, and right medial superior frontal regions. Planned ART interruption did not affect development of cortical morphometry.

CONCLUSIONS

Although our results suggest that normal development of cortical morphometry between the ages of 5 and 9 years is preserved in CPHIV who started ART early, these findings require further confirmation with longitudinal follow-up through the vulnerable adolescent period.

Rapid neurodevelopmental recovery after ART initiation in an infant with HIV encephalopathy

While there is ample evidence that antiretroviral therapy (ART) can improve cognitive outcomes in older children living with HIV, encephalopathy in infants has historically been considered an advanced disease presentation with less likelihood of neurodevelopmental recovery on treatment. More recent studies suggest that timely ART can halt encephalopathic disease progression and even lead to symptom resolution. Here we present a case of an HIV-positive infant diagnosed with encephalopathy who experienced impressive and rapid improvement with a multi-disciplinary care approach that included physical and occupational therapy and ART.

HIV Encephalopathy in ART-Naïve, Hospitalized Infants in Mozambique

INTRODUCTION

The neurodevelopmental impact of HIV infection in older children has been well-described, with characterization of HIV-associated encephalopathy (HIVE) and associated cognitive defects. HIVE is relatively common in older children who were vertically infected. The sparse literature on HIVE in infants suggests that incidence may be up to 10% in the first year of life, but no studies were identified that specifically evaluated hospitalized infants.

METHODS

A descriptive study of routine inpatient data from two central referral hospitals in Mozambique was conducted. Inclusion criteria were infants with confirmed HIV infection aged <12 months, not on ART, admitted between 1 January 2019 and 30 June 2019. Presumptive HIVE was defined as having delayed developmental milestones in addition to microcephaly and/or pathological reflexes.

RESULTS

Seven out of 27 patients (26%) were classified as presumptive HIVE. Delayed milestones were seen in 18 patients (67%) and the prevalence was approximately two times higher in the HIVE (+) group across all milestone categories. Delayed or no maternal ART (p = 0.03) and the infant not having received postnatal nevirapine prophylaxis (p = 0.02) were significantly associated with HIVE.

CONCLUSIONS

HIVE prevalence is high in ART naïve hospitalized infants, particularly in those with risk factors for in-utero transmission. Thorough neurologic and developmental assessments can help identify HIV-infected infants and can be of particular utility in pediatric wards without access to point-of-care virologic testing where presumptive HIV diagnosis is still needed. Infants with HIVE need comprehensive care that includes antiretroviral therapy and physical/occupational therapy.

The effect of HIV infection and exposure on cognitive development in the first two years of life in Malawi

OBJECTIVES

To assess longitudinal patterns and determinants of cognitive development in infants living with HIV, infants exposed to maternal HIV infection, and HIV-unexposed infants.

METHODS

Prospective, community-based cohort study of 555 Malawian infants aged 8 weeks to 24 months, using multivariable linear mixed-effects regression models with random intercepts to analyze repeated measures of cognitive function.

RESULTS

At 3 months of age, cognitive scores on the Bayley Scales of Infant Development (BSID 3rd edition) were lower in the 96 HIV-infected infants (mean = 14.1 (SD:4.8)) compared to the 289 HIV-exposed (mean = 16.5 (SD:3.7)) and the 170 unexposed infants (mean = 17.5 (SD:3.3)). Over the first two years of life, the small deficit in cognitive development of infants living with HIV who survived and remained in care did not increase (mean score 52.9 among HIV-infected vs 55.6 among HIV unexposed). In multivariable analysis, malnutrition and a more advanced clinical infant HIV stage had a negative impact on cognition at age 3, while financial security, care by the biological mother, and ART for mother and child were associated with better cognitive status at this young age. The positive influence of maternal ART reversed with age.

CONCLUSIONS

Malawian infants exposed to HIV had a cognitive development that was similar to their unexposed peers in the first two years of life, while that of HIV infected infants lagged behind from the start. Early initiation of effective ART in all HIV infected mothers and infants, and prevention of infant malnutrition are important to safeguard cognitive development of children affected by HIV.

Left ventricular systolic function in Nigerian children infected with HIV/AIDS: a cross-sectional study

Background

Cardiac complications contribute significantly to morbidity and mortality in children with HIV/AIDS. These rates have been under-reported in sub-Saharan African children.

Methods

This was an observational, cross-sectional Doppler echocardiographic study of ventricular systolic function, performed at a tertiary clinic on children with HIV/AIDS.

Results

Left ventricular systolic dysfunction was present in 27.0% of the children with HIV infection and 81.2% of those with AIDS. The mean fractional shortening in the AIDS group (31.6 ± 9.5%) was significantly lower than in the HIV-infected group (35.3 ± 10.5%, p = 0.001). A significant correlation was found with CD4+ cell count and age, and these were the best predictors of left ventricular systolic dysfunction in the stepwise multiple regression analysis (r = 0.396, p = 0.038; r = –0.212, p = 0.025, respectively).

Conclusion

Left ventricular systolic dysfunction is common in Nigerian children with HIV/AIDS.

Treatment initiation factors and cognitive outcome in youth with perinatally acquired HIV infection

OBJECTIVES

Although cognitive outcomes among perinatally infected youth have improved with highly active antiretroviral therapy (HAART), the impact of the age of initiation of treatment and the central nervous system (CNS) penetration effectiveness (CPE) of the regimen on cognitive outcomes is unknown. We aimed to describe the association between initiation age/regimen CPE score and cognitive outcomes in perinatally HIV-infected youth.

METHODS

Linear regression was used to retrospectively assess the association between full-scale IQ score (FSIQ) and age of initiation of HAART, regimen CPE, and the presence/absence of an AIDS diagnosis before initiation of HAART in an urban US cohort.

RESULTS

A total of 88 of 181 subjects (48.6%) had an AIDS diagnosis. In 69, AIDS preceded the start of HAART. Mean FSIQ (mean age 155.4 months) was 86.3 [standard deviation (SD) 15.6]. Neither age of initiation of HAART (P = 0.45) nor regimen CPE score (P = 0.33) was associated with FSIQ. Mean FSIQ for patients with an AIDS diagnosis before HAART initiation [82 (SD 17.0)] was significantly lower than for patients initiating HAART before an AIDS diagnosis [90 (SD 13)] (P = 0.001). Of the 129 subjects without AIDS by age 5 years, 41 (31.8%) initiated HAART before age 5 years; four of 41 later developed AIDS, compared with 32 of 88 of those who did not initiate HAART before age 5 years. The relative risk of AIDS if HAART was initiated before age 5 years was 0.19 (95% confidence interval 0.05-0.60).

CONCLUSIONS

Earlier age at HAART initiation and higher CPE score of a regimen did not improve cognitive outcomes. However, initiating HAART prior to AIDS protected against AIDS and was associated with a significantly higher FSIQ.

HIV Encephalopathy: pediatric case series description and insights from the clinic coalface

Background

The Human Immune Deficiency Virus (HIV) can manifest neurologically in both adults and children. Early invasion of the central nervous system by the virus, affecting the developing brain, is believed to result in the most common primary HIV-related neurological complication, HIV Encephalopathy (HIVE). In countries such as South Africa where many children have not been initiated on antiretroviral treatment early, HIVE remains a significant clinical problem.

Methods

Children were selected from a clinic for children with neurologic complications of HIV, located at the Red Cross War Memorial Children’s Hospital, South Africa 2008–2012. Eligible subjects fulfilled the following inclusion criteria: aged 6 months-13 years; positive diagnosis of HIV infection, vertically infected and HIVE as defined by CDC criteria. Each participant was prospectively assessed by a Pediatric Neurologist using a standardized proforma which collated relevant details of background, clinical and immunological status.

Results

The median age of the 87 children was 64 months (interquartile range 27–95 months). All except one child were on antiretroviral treatment, 45% had commenced treatment <12 months of age. Delayed early motor milestones were reported in 80% and delayed early speech in 75% of children in whom we had the information. Twenty percent had a history of one or more seizures and 41% had a history of behavior problems. Forty-eight percent had microcephaly and 63% a spastic diplegia. CD4 percentages followed a normal distribution with mean of 30.3% (SD 8.69). Viral loads were undetectable (<log 1.6) in 70% of the children. Brain imaging was performed on 56% with 71% of those imaged demonstrating at least one abnormality, most commonly white matter volume loss or signal abnormality.

Conclusions

Amongst the cohort of children referred to this clinic, the diagnosis of HIVE was unrecognized in the general medical services, even in its most severe form. Developmental delay and school failure were major presenting problems. Co-morbidities are a frequent finding and should be sought actively in order to optimize management and promote best possible outcomes for this vulnerable group of children.

Neurologic complications of pediatric human immunodeficiency virus: implications for clinical practice and management challenges in the African setting

Approximately 3.4 million children worldwide are affected with human immunodeficiency virus (HIV)/AIDS with more than 90% of them residing in sub-Saharan Africa, according to the World Health Organization. A significant proportion of the children eligible for treatment with antiretroviral therapy are not currently receiving it. Neurologic manifestations of HIV are common in both adults and children. There is a large spectrum of neurologic conditions that may be caused by the virus; however, early invasion of the central nervous system by the virus, affecting the developing fetal and infant brain, is believed to result in the most common primary HIV-related central nervous system complication, HIV encephalopathy. This article summarizes the spectrum of neuro-HIV in children, focuses on the neurocognitive and behavioral sequelae, reviews the effects of treatment on the primary neurologic effects of the disease, and discusses the specific challenges of identifying and managing these problems in resource-limited contexts, such as those found on the African continent.

An unusual case of hyperlactataemia in a neonate

We report a HIV uninfected neonate born to HIV positive mother, who had tachypnoea at birth. On investigations, he was found to have hyperlactataemia. All the secondary causes for elevated lactate were ruled out. Hyperlactataemia was attributed to the perinatal exposure, to maternal antiretroviral (ARV) drugs, mainly nucleoside analogues. Asymptomatic and symptomatic hyperlactataemia is not uncommon in HIV-exposed infants. Neonates with tachypnoea, who are HIV- and ARV-exposed with no obvious cause, should be screened for raised arterial lactate.

Neurocognitive function in HIV-positive children in a developing country

OBJECTIVES

We aimed to characterize neurological outcomes and determine the prevalence of HIV encephalopathy in a cohort of HIV-infected children in Jamaica.

METHODS

Data for 287 HIV-infected children presenting between 2002 and 2008 were reviewed and neurological outcomes characterized. A nested case-control study was conducted between July and September 2009 used 15 randomly selected encephalopathic HIV-infected children aged 7-10 years and 15 matched controls (non-encephalopathic HIV-infected). Their neurocognitive functions were evaluated using clinical assessment and standardized tests for intelligence, short term memory (visuo-spatial and auditory), selective attention, and fine motor and coordination functions. Outcomes were compared using Fisher's exact test and the Mann-Whitney U-test.

RESULTS

Sixty-seven (23.3%) children were encephalopathic. The median age at diagnosis of HIV encephalopathy was 1.6 years (interquartile range (IQR) 1.1-3.4 years). Predominant abnormalities were delayed milestones (59, 88.1%), hyperreflexia (59, 86.5%), spasticity (50, 74.6%), microcephaly (42, 61.7%), and quadriparesis (21, 31.3%). The median age of tested children was 8.7 years (IQR 7.6-10.8 years) in the encephalopathic group and 9 years (IQR 7.4-10.7 years) in the non-encephalopathic group. Encephalopathic children performed worse in all domains of neurocognitive function (p<0.05).

CONCLUSIONS

A high prevalence of HIV encephalopathy was noted, and significant neurocognitive dysfunction identified in encephalopathic children. Optimized management through the early identification of neurological impairment and implementation of appropriate interventions is recommended to improve quality of life.

Prevalence of seizures in children infected with human immunodeficiency virus

A retrospective study of 354 human immunodeficiency virus (HIV)-infected patients identified a subgroup of 27 children with seizures (7.6%, 95% confidence interval: 5.1%-10.9%). Of the total group, 13% (n = 46) had identifiable neurologic deficits and 30% (n = 107) had developmental delay. Both observations were significantly more frequent in the subgroup of patients with seizures (P < .001). The median age of patients with seizures was 20 months (range, 8-87 months) and the median baseline CD4 percentage was 13.5% (interquartile range, 8%-23%). Seizures were treated with sodium valproate (n = 11), phenobarbital (n = 3), diazepam (n = 2), lamotrigine (n = 1), and carbamazepine (n = 1). Combination therapy was required for 5 children. Suboptimal valproic acid levels were recorded for 3 patients. When resources are available, antiepileptic drug level monitoring is advised for children who require both antiepileptic and antiretroviral medications to facilitate optimal seizure management.

When to start, what to start and other treatment controversies in pediatric HIV infection

Over the last decade there have been dramatic changes in the management of pediatric HIV infection. Whilst observational studies and several randomized control trials (RCTs) have addressed some questions about when to start antiretroviral therapy (ART) in children and what antiretrovirals to start, many others remain unanswered. In infants, early initiation of ART greatly reduces mortality and disease progression. Treatment guidelines now recommend ART in all infants younger than 1 or 2 years of age depending on geographical setting. In children >1 year of age, US, European (Paediatric European Network for Treatment of AIDS; PENTA) and WHO guidelines differ and debate is ongoing. Recent data from an RCT in Thailand in children with moderate immune suppression indicate that it is safe to monitor asymptomatic children closely without initiating ART, although earlier treatment was associated with improved growth. Untreated HIV progression in children aged over 5 years is similar to that in adults, and traditionally adult treatment thresholds are applied. Recent adult observational and modeling studies showed a survival advantage and reduction of age-associated complications with early treatment. The current US guidelines have lowered CD4+ cell count thresholds for ART initiation for children aged >5 years to 500 cells/mm3. Co-infections influence the choice of drugs and the timing of starting ART. Drug interactions, overlapping toxicities and adherence problems secondary to increased pill burden are important issues. Rapid changes in the pharmacokinetics of antiretrovirals in the first years of life, limited pharmacokinetic data in children and genetic variation in metabolism of many antiretrovirals make correct dosing difficult. Adherence should always be addressed prior to starting ART or switching regimens. The initial ART regimen depends on previous exposure, including perinatal administration for prevention of mother to child transmission (PMTCT), adherence, co-infections, drug availability and licensing. A European cohort study in infants indicated that treatment with four drugs produced superior virologic suppression and immune recovery. Protease inhibitor (PI)-based ART has the advantage of a high barrier to viral resistance. A recent RCT conducted in several African countries showed PI-based ART to be advantageous in children aged <3 years compared with nevirapine-based ART irrespective of previous nevirapine exposure. Another trial in older children from resource rich settings showed both regimens were equally effective. Treatment interruption remains a controversial issue in children, but one study in Europe demonstrated no short-term detrimental effects. ART in children is a rapidly evolving area with many new antiretrovirals being developed and undergoing trials. The aim of ART has shifted from avoiding mortality and morbidity to achieving a normal life expectancy and quality of life, minimizing toxicities and preventing early cancers and age-related illnesses.

Neurodevelopment in children born to HIV-infected mothers by infection and treatment status

BACKGROUND

We reviewed the impact of HIV, HIV exposure, and antiretroviral therapy/prophylaxis on neurodevelopmental outcomes of HIV-infected and HIV-exposed-uninfected infants and children.

METHODS

A literature search of Medline, Embase, PsychINFO, Web of Science, PubMed, and conference Web sites (1990-March 2011) using the search terms, infant, child, HIV, neurodevelopment, cognition, language, and antiretroviral therapy, identified 31 studies of HIV/antiretroviral exposure using standardized tools to evaluate infant/child development as the main outcome. Articles were included if results were reported in children <16 years of age who were exposed to HIV and antiretrovirals in fetal/early life, and excluded if children did not acquire HIV from their mothers or were not exposed to antiretrovirals in fetal/early life.

RESULTS

Infants who acquired HIV during fetal and early life tended to display poorer mean developmental scores than HIV-unexposed children. Mean motor and cognitive scores were consistently 1 to 2 SDs below the population mean. Mean scores improved if the infant received treatment before 12 weeks and/or a more complex antiretroviral regimen. Older HIV-infected children treated with highly active antiretroviral therapy demonstrated near normal global mean neurocognitive scores; subtle differences in language, memory, and behavior remained. HIV-exposed-uninfected children treated with antiretrovirals demonstrated subtle speech and language delay, although not universally.

CONCLUSIONS

In comparison with resource-rich settings, HIV-infected and HIV-exposed-uninfected infants/children in resource-poor settings demonstrated greater neurodevelopmental delay compared with HIV-unexposed infants. The effects on neurodevelopment in older HIV-infected children commenced on antiretroviral therapy from an early age and HIV-exposed-uninfected children particularly in resource-poor settings remain unclear.

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

OBJECTIVE

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSION

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

beta-Chemokine production by neural and glial progenitor cells is enhanced by HIV-1 Tat: effects on microglial migration

Human immunodeficiency virus (HIV)-1 neuropathology results from collective effects of viral proteins and inflammatory mediators on several cell types. Significant damage is mediated indirectly through inflammatory conditions promulgated by glial cells, including microglia that are productively infected by HIV-1, and astroglia. Neural and glial progenitors exist in both developing and adult brains. To determine whether progenitors are targets of HIV-1, a multi-plex assay was performed to assess chemokine/cytokine expression after treatment with viral proteins transactivator of transcription (Tat) or glycoprotein 120 (gp120). In the initial screen, ten analytes were basally released by murine striatal progenitors. The beta-chemokines CCL5/regulated upon activation, normal T cell expressed and secreted, CCL3/macrophage inflammatory protein-1alpha, and CCL4/macrophage inflammatory protein-1beta were increased by 12-h exposure to HIV-1 Tat. Secreted factors from Tat-treated progenitors were chemoattractive towards microglia, an effect blocked by 2D7 anti-CCR5 antibody pre-treatment. Tat and opiates have interactive effects on astroglial chemokine secretion, but this interaction did not occur in progenitors. gp120 did not affect chemokine/cytokine release, although both CCR5 and CXCR4, which serve as gp120 co-receptors, were detected in progenitors. We postulate that chemokine production by progenitors may be a normal, adaptive process that encourages immune inspection of newly generated cells. Pathogens such as HIV might usurp this function to create a maladaptive state, especially during development or regeneration, when progenitors are numerous.

The impact of AIDS diagnoses on long-term neurocognitive and psychiatric outcomes of surviving adolescents with perinatally acquired HIV

OBJECTIVE

To explore the association between previous severe HIV disease, defined as past Centers for Disease Control and Prevention class C diagnosis, and neurocognitive and psychiatric outcomes in long-term survivors of perinatally acquired HIV.

DESIGN

A retrospective cohort study of perinatally HIV-infected adolescents receiving outpatient care at a single site.

METHODS

Comparisons were made between those with and without class C diagnoses.

RESULTS

Eighty-one patients formed the study group, 47% were females and 72% were African-American. Median patient age was 15 years (interquartile range 13-17). Of the study group, 47% had a past class C diagnosis. The median age at class C diagnosis was 3.1 years (interquartile range 0.9-8.1). There were no significant differences between the groups with respect to most recent CD4(+) cell percentage or plasma viral RNA level. Class C patients were more likely to have a history of psychiatric diagnosis [odds ratio 2.6; 95% confidence interval (CI) 1.1-6.3], psychiatric hospitalization (odds ratio 4.8; 95% CI 1.2-17.4), or learning disability (odds ratio 4.5; 95% CI 1.7-11.4). There was a significant difference in full-scale intelligence quotient between the groups (adjusted linear regression coefficient -11.7; 95% CI -17.9 to 5.5). After adjusting for age at antiretroviral therapy initiation, the associations between class C diagnosis and lower full-scale intelligence quotient, learning disorders, and psychiatric diagnoses remained significant.

CONCLUSION

A distant history of AIDS diagnosis was associated with an increased risk of neurocognitive and psychiatric impairment in adolescents with perinatally acquired HIV. Further research should help delineate if early treatment, possibly soon after birth and definitely prior to AIDS diagnosis, might lead to improved outcomes.

Impact of HAART and CNS-penetrating antiretroviral regimens on HIV encephalopathy among perinatally infected children and adolescents

OBJECTIVES

Prior to antiretroviral treatment, HIV-infected children frequently developed encephalopathy, resulting in debilitating morbidity and mortality. This is the first large study to evaluate the impact of HAART and central nervous system (CNS)-penetrating antiretroviral regimens on the incidence of HIV encephalopathy and survival after diagnosis of HIV encephalopathy among perinatally infected children.

DESIGN

A total of 2398 perinatally HIV-infected children with at least one neurological examination were followed in a US-based prospective cohort study conducted from 1993 to 2007.

METHODS

Trends in incidence rates over calendar time were described and Cox regression models were used to estimate the effects of time-varying HAART and CNS-penetrating antiretroviral regimens on HIV encephalopathy and on survival after diagnosis of HIV encephalopathy.

RESULTS

During a median of 6.4 years of follow-up, 77 incident cases of HIV encephalopathy occurred [incidence rate 5.1 cases per 1000 person-years, 95% confidence interval (CI) 4.0-6.3]. A 10-fold decline in incidence was observed beginning in 1996, followed by a stable incidence rate after 2002. HAART regimens were associated with a 50% decrease (95% CI 14-71%) in the incidence of HIV encephalopathy compared with non-HAART regimens. High CNS-penetrating regimens were associated with a substantial survival benefit (74% reduction in the risk of death, 95% CI 39-89%) after HIV encephalopathy diagnosis compared with low CNS-penetrating regimens.

CONCLUSION

A dramatic decrease in the incidence of HIV encephalopathy occurred after the introduction of HAART. The use of HAART was highly effective in reducing the incidence of HIV encephalopathy among perinatally infected children and adolescents. Effective CNS-penetrating antiretroviral regimens are important in affecting survival after diagnosis of HIV encephalopathy.

Brief report: language ability and school functioning of youth perinatally infected with HIV

INTRODUCTION

The purpose of this article is to describe the language ability and school functioning of early adolescents with perinatal HIV/AIDS.

METHOD

Participants included 43 youths, 9-15 years, and their primary caregivers. Youths completed the Peabody Picture Vocabulary Test (PPVT) and the Reading Subtest of the Wide Range Achievement Test (WRAT3) and were interviewed regarding their future educational aspirations and parental supervision and involvement with homework. Caregivers were interviewed regarding the child's school achievement, parental supervision and monitoring, and educational aspirations for their child.

RESULTS

Fifty-four percent of youths scored below average (<25th percentile) on the PPVT, and 29% scored below the 10th percentile; 40% scored below average (<25th percentile) on the WRAT3, and 24% scored below the 10th percentile. Scores were associated with parental monitoring and educational aspirations.

DISCUSSION

Youths performed poorly on tests of verbal and reading ability, although their scores were not dissimilar to those of other samples of inner-city youths. Future research should attempt to isolate the impact of HIV disease on intellectual and school functioning of HIV+ youths.

The ART of HIV therapies: dopaminergic deficits and future treatments for HIV pediatric encephalopathy

The concerted efforts of clinicians, scientists and caregivers of HIV-infected children have led to tremendous advances in our understanding of pediatric HIV/AIDS. Antiretroviral therapy (ART; formerly known as highly active antiretroviral therapy [HAART]) has significantly extended the longevity of HIV-infected children, but there are limitations to improvements in quality of life that may persist despite therapy. ART has remarkably reduced the incidence of neurologic deficits for the majority of infected children, but some patients do not experience these benefits and children living in poorer nations, who may not have access to antiretrovirals, are particularly at risk for developing neurologic deficits. This article reviews the neurologic symptoms of pediatric HIV infection that manifest as dopaminergic disruptions and explores potential future adjuvant therapies for HIV-related neurologic disorders in children.

Second assessment of NeuroAIDS in Africa

In July of 2006, the National Institute of Mental Health (NIMH) Center for Mental Health Research on AIDS (CMHRA) sponsored the second conference on the Assessment of NeuroAIDS in Africa, which was held in Arusha, Tanzania. The conference mission was to address the regional variations in epidemiology of HIV-related neurological disorders as well as the assessment and diagnosis of these disorders. Participants discussed and presented data regarding the relevance and translation of neuroAIDS assessment measures developed in resource intensive settings and the challenges of neuro-assessment in Africa, including the applicability of current tools, higher prevalence of confounding diseases, and the complexity of diverse cultural settings. The conference presentations summarized here highlight the need for further research on neuroAIDS in Africa and methods for assessing HIV-related neurological disorders.

Impact of the HIV/AIDS epidemic on the neurodevelopment of preschool-aged children in Kinshasa, Democratic Republic of the Congo

OBJECTIVES

Pediatric HIV infection is a growing problem in most regions of the world. Data on the effects of HIV on the neurodevelopment of children in resource-poor settings are scarce but necessary to guide interventions. The purpose of this study was to compare the neurodevelopment of preschool-aged HIV-infected, HIV-affected (HIV-uninfected AIDS orphans and HIV-uninfected children whose mother had symptomatic AIDS), and healthy control children in Kinshasa, Democratic Republic of Congo.

METHODS

Thirty-five HIV-infected, 35 HIV-affected, and 90 control children aged 18 to 72 months were assessed by using the Bayley Scales of Infant Development II, Peabody Developmental Motor Scales, Snijders-Oomen Nonverbal Intelligence Test, and Rossetti Infant-Toddler Language Scale, as appropriate for age.

RESULTS

Overall, 60% of HIV-infected children had severe delay in cognitive function, 29% had severe delay in motor skills, 85% had delays in language expression, and 77% had delays in language comprehension, all significantly higher rates as compared with control children. Young HIV-infected children (aged 18-29 months) performed worse, with 91% and 82% demonstrating severe mental and motor delay, respectively, compared with 46% and 4% in older HIV-infected children (aged 30-72 months). HIV-affected children had significantly more motor and language expression delay than control children.

CONCLUSIONS

The impact of the HIV pandemic on children's neurodevelopment extends beyond the direct effect of the HIV virus on the central nervous system. AIDS orphans and HIV-negative children whose mothers had AIDS demonstrated significant delays in their neurodevelopment, although to a lesser degree and in fewer developmental domains than HIV-infected children. Young HIV-infected children were the most severely afflicted group, indicating the need for early interventions. Older children performed better as a result of a "survival effect," with only those children with less aggressive disease surviving.

Does HIV-1/AIDS-associated frontotemporal neuropathology following perinatal infection influence the development of moral behaviour?

While HIV encephalopathy and the AIDS dementia complex are considered hallmark neurologic manifestations of HIV-1 infection, increasing evidence of a continuum of nervous system involvement indicates the existence of an unrecognized number of individuals with milder, mostly cognitive and/or behavioural effects. Questions are raised whether HIV-related frontotemporal neuropathology during critical developmental stages could affect development of the brain networks documented to be involved in moral decisions, and whether this could contribute to the phenomenon of delinquency in an unknown percentage of the current generation of approximately 18-25 year old survivors of early childhood or vertically acquired HIV infection. Carefully planned and executed long term, prospective controlled studies using environmental, clinical, neurological, behavioural, genetic, immune and functional neuroimaging correlates would be required to elucidate whether HIV-specific neuropathology could indeed act as an independent risk factor for the development of a frontotemporal sociopathy syndrome. If such an association is proven, the accelerated development of neurospecific therapies should be a priority, especially for clinically and immunologically stable HIV-infected children. It may be necessary to institute such treatment as early as possible in perinatally infected cases, and maybe even during intrauterine life if HIV-1 is demonstrated to also act as a neurobehavioural teratogen for the developing fetal brain. It may, however, prove to be difficult to separate primary neurobiological from environmental factors, since the epigenetic effects on the host genome of retroviral insertion influencing behavioural gene expression characteristics, and altered gene expression following early life stresses may involve overlapping neurodevelopmental gene regulatory networks. In the meantime it remains necessary to prevent or ameliorate frequent neuropsychiatric morbidity from whatever causes.

Psychiatric morbidity in HIV-infected children

After the introduction of antiretroviral therapy, HIV infection in children has been transformed from an acute to a chronic illness. The number of HIV-infected children has also increased in recent years. The routes of transmission and clinical manifestation of HIV infection in children are unique and different from those of adults. There are a number of biological, psychological and social factors associated with HIV-infected child that may predispose him/her to develop psychiatric illness. However, there are very few studies on psychiatric morbidity in HIV-infected children. In the existing studies, a number of psychiatric illnesses including: depression, anxiety, disruptive disorders and hyperactive disorders have been observed in HIV-infected children. A number of variables have a bearing on psychiatric morbidity, including experience and expression of physical illness as well as adherence to medications. The physician dealing with HIV-infected children should be aware of the psychological manifestations so that appropriate interventions and referral may be made as needed.

Neurologic and neurodevelopmental manifestations of pediatric HIV/AIDS: a global perspective

Neurodevelopmental abnormalities associated with HIV infection have been described since the first reports of pediatric AIDS in the 1980s. Before antiretroviral therapy (ART) became widely available, progressive HIV-1 encephalopathy (PHE) was reported in the US in 13-35% of children with HIV-1 infection and in 35-50% of children with AIDS. Introduction of ART can prevent PHE and reverse PHE present at ART initiation, but a high prevalence of residual problems has been described. Even though 90% of HIV-infected children live in the developing world, few children have access to ART and little is known regarding the neurological manifestations of perinatal HIV infection in those regions. Mechanisms of pediatric HIV-1 neuropathogenesis and factors associated with neurodevelopmental abnormalities in perinatally infected children are not yet fully understood. Studies have demonstrated that HIV-1 enters the CNS soon after infection and may persist in this compartment over the entire course of HIV-1 infection. The CNS is a distinct viral reservoir, differing from peripheral compartments in target cells and antiretroviral penetration. Neurotropic HIV-1 likely develops distinct genotypic characteristics in response to this unique environment. We reviewed the literature on pediatric neuroAIDS and identified gaps in the current knowledge.

Salvage therapy with abacavir and other reverse transcriptase inhibitors for human immunodeficiency-associated encephalopathy

BACKGROUND

HIV-associated encephalopathy (HIV-AE) is a severe neurologic condition that affects HIV-infected children. The potential benefit of antiretroviral (ARV) agents with good cerebrospinal fluid (CSF) penetration remains to be defined. Abacavir (ABC) achieves good CSF concentrations and studies of high-dose ABC showed benefit in adults with HIV dementia. The present study evaluated the safety and virologic, immunologic and neuropsychological responses of an ARV regimen including high-dose ABC in children with HIV-AE.

METHODS

Children between 3 months and 18 years old and abacavir-naive with HIV-AE and virologic failure were eligible.

RESULTS

: Seventeen children (16 ARV-experienced) were enrolled and 14 children completed 48 weeks of therapy. The overall tolerability was good; 2 children had a possible hypersensitivity reaction. At week 48, 53% and 59% of the children achieved HIV RNA levels below the limit of quantitation in plasma and CSF, respectively. The median (25%-75% range) change of HIV RNA from baseline to week 48 was -2.29 (-0.81 to -2.47) log10 copies/mL in plasma and -0.94 (0 to -1.13) log10 copies/mL in CSF. The mean increases in CD4 (+/-standard error of mean) cell count and CD4% were 427 (+/-169) cells/mm and 8% (+/-2), respectively. Concentrations of soluble tumor necrosis factor receptor II were reduced in plasma and CSF. Children less than 6 years of age demonstrated significant neuropsychological improvement at week 48.

CONCLUSIONS

In the present study with a limited number of children, highly active ARV therapy including high-dose ABC showed a safety profile similar to standard dose ABC and provided clinical, immunologic and virologic response in children with HIV-AE at week 48. Children less than 6 years of age also demonstrated significant neuropsychological improvement.

Specific neurologic complications of human immunodeficiency virus type 1 (HIV-1) infection in children

Pediatric human immunodeficiency virus type 1 (HIV-1) infection is endemic throughout southern Africa. Neurologic complications are described in 20% to 60% of published series, mostly related to HIV-1 encephalopathy. With increasing HIV prevalence, more atypical cases are presenting. We present, as illustrative cases, seven children (three girls) with unusual neurologic sequelae as a consequence of HIV-1 infection. The median age at presentation was 33 months (range 7 months-6 years). Five of the seven children were developmentally normal before presentation. They presented with progressive multifocal leukoencephalopathy, myelopathy, intractable seizures, acute vasculitis and blindness, hemiplegia, peripheral neuropathy, and paraspinal lymphoma. Neuroimaging of the brain was performed in five patients, of whom one had basal ganglia calcification. All children had poor outcome with incomplete recovery or continued deterioration. In conclusion, children with HIV-1 infection who survive beyond the first year of life can present with a wide variety of neurologic complications. A similar spectrum of neurologic manifestations is likely to occur in other sub-Saharan African countries, characterized by high HIV prevalence. The case histories demonstrate that the neurologic features of pediatric HIV infection do not easily fit into a simplified classification system.

Cognitive and motor deficits associated with HIV-2(287) infection in infant pigtailed macaques: a nonhuman primate model of pediatric neuro-AIDS

Lentivirus-infected nonhuman primates exhibit behavioral and neurological pathology similar to human immunodeficiency virus (HIV)-infected humans and offer a means to examine the effects of lentivirus infection while controlling for confounding factors inherent in human populations. The purpose of this study was to examine cognitive and motor development in infant macaques vertically infected with HIV-2287. Subjects were 20 infant pigtail macaques (Macaca nemestrina); 8 controls born to uninfected dams, and 12 infants whose dams had been inoculated and infected with HIV-2287 in the third trimester of pregnancy. Eight of these pregnancies had undergone surgical procedures in the form of maternal amniotic catheters or maternal amniotic and fetal carotid artery and jugular vein catheters. Data indicated that catheterization had little or no impact on behavioral development. Seven infants were vertically infected (as measured by polymerase chain reaction (PCR) at birth) and five were not infected (as measured by PCR and coculture on repeated testing). Infected infants attained cognitive and motor milestones at significantly later ages than controls. Uninfected infants, born to infected dams, attained developmental milestones at later ages than controls on all tasks, but this reached statistical significance only for the Fine Motor Task. Attainment of milestones was not correlated with viral dose, maternal CD4+ levels at parturition or infant viral RNA levels at birth. Attainment of milestones was negatively correlated with infants' proportions of CD4+ lymphocytes at birth and significantly correlated with proportions of CD4+ lymphocytes 2 weeks after birth, indicating poorer performance in those infants with a more rapid CD4+ depletion. These cognitive and motor deficits closely resemble those observed in human infants and children infected with HIV and indicate that HIV-2287-infected infant macaques represent an excellent model of pediatric neuro-acquired immunodeficiency syndrome (neuroAIDS).

Incidence and prevalence of HIV encephalopathy in children with HIV infection receiving highly active anti-retroviral therapy (HAART)

OBJECTIVE

To describe neurologic outcomes in children infected with HIV in the era of highly active anti-retroviral therapy (HAART), including rates of progressive HIV encephalopathy (PHE) and clinical sequelae among PHE survivors.

STUDY DESIGN

Neurobehavior and school placement was assessed prospectively in the year 2000 in 126 children infected with HIV. PHE, developmental delay, and attention deficit disorder (ADHD) were the main outcome variables analyzed. Predictors of PHE were assessed in controlled analysis among age-matched controls.

RESULTS

The rate of active PHE in 2000 was 1.6% (n = 2), and the prevalence of arrested PHE was 10% (n = 13). Residual motor and cognitive sequelae and need for special education was found in the majority of survivors. PHE relapse occurred in 3 (23%) children with previously arrested PHE. Viral load (VL) was the only significant factor associated with PHE. HIV or PHE was not associated with ADHD. Isolated developmental delay was not associated with HIV.

CONCLUSIONS

PHE is an infrequent and reversible complication of HIV infection that responds to HAART and that may relapse if control of the virus is lost. Children with arrested PHE show higher rates of residual neurologic, cognitive, and scholastic impairments compared with children who never had PHE. Children with arrested PHE are the group of children with HIV infection most at risk for PHE, in the form of a relapse.

Neuropsychological functioning and viral load in stable antiretroviral therapy-experienced HIV-infected children

OBJECTIVE

Neuropsychological functioning and its correlation with viral load were investigated for previously treated HIV-infected children who underwent a change in treatment regimen.

METHODS

Thirteen age-appropriate measures of cognitive, neurologic, and behavioral functioning were administered to 489 HIV-infected children who were aged 4 months to 17 years and had been treated previously for at least 16 weeks with antiretroviral therapy. These clinically and immunologically stable children were randomized onto 1 of 7 drug treatment combinations, 6 of which included a protease inhibitor (PI), and evaluated prospectively for 48 weeks with respect to changes in neuropsychological performance and viral load.

RESULTS

Neuropsychological functioning was significantly poorer at baseline for the HIV-infected children as compared with established norms for their age. Children with higher viral load had poorer cognitive, both-hands fine-motor, and neurologic signs at baseline, but single-hand fine-motor and behavioral functioning were not correlated with viral load. After 48 weeks of treatment with PI-containing combination therapy, there was significant improvement in only the vocabulary score. Neuropsychological changes did not differ among the 6 PI-containing combination regimens. At week 48, even children with a viral load response below the level of detection (RNA < or =400 copies/mL) still showed poorer neuropsychological functioning compared with established norms.

CONCLUSION

Poor neuropsychological functioning was seen for HIV-infected children and was worse for children with higher viral loads. Only 1 measure of neuropsychological functioning showed improvement after treatment with PI-containing combination therapy, and the extent of that improvement was relatively minor. Treatment strategies for children with HIV disease need to be reevaluated so that they consider restoration of neuropsychological functioning in addition to lowering the viral load.

Cerebrospinal fluid and plasma concentrations of proinflammatory mediators in human immunodeficiency virus-infected children

BACKGROUND

The pathogenesis of HIV encephalopathy is poorly understood especially in children. Studies suggest that HIV replication and the release of proinflammatory mediators in the central nervous system contribute to the pathogenesis of HIV dementia in adults.

METHODS

Cerebrospinal fluid (CSF) and plasma samples from 23 HIV-infected children were longitudinally analyzed at Weeks 0, 8, 16 and 48 for HIV RNA and concentrations of the following proinflammatory mediators: monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha, regulated upon activation, normal T cell expressed and secreted (RANTES), macrophage-inflammatory protein (MIP)-1-alpha, MIP-1-beta and matrix metalloproteinase-9 (MMP-9).

RESULTS

All 23 children had detectable concentrations of MCP-1 in the CSF at all time points evaluated. However, of the remaining of proinflammatory mediators measured in CSF at baseline, only a few children had detectable concentrations: tumor necrosis factor-alpha, n = 1; RANTES, n = 5; MMP-9, n = 9; MIP-1-alpha and MIP-1-beta, n = 0. A reduction from baseline to Week 48 was observed in CSF concentrations of MCP-1 and, among children with detectable values, MMP-9, which paralleled declines in CSF HIV RNA.

CONCLUSION

These results suggest that MCP-1 and MMP-9 may be involved in the pathogenesis of central nervous system disease in HIV-infected children.

Neuroprotective effects of early antiretrovirals in vertical HIV infection

We performed a retrospective study of a series of 58 of 189 vertically HIV-1 infected children who went on to develop progressive HIV-1-associated encephalopathy to assess real-life effects of early antiretroviral therapy on neurologic outcome. Our findings clearly indicate that antiretroviral therapy before the onset of neurologic symptoms delayed presentation of progressive HIV-1-associated encephalopathy, with an additional beneficial effect on survival.

Cognitive decline with immunologic and virologic stability in four children with human immunodeficiency virus disease

This case series describes 4 children with vertically acquired human immunodeficiency virus (HIV) infection who exhibited immunologic, virologic, and clinical stability while on a protease inhibitor-containing highly active antiretroviral therapy (HAART) regimen, yet demonstrated significant cognitive decline as measured by standardized intelligence tests. A retrospective review of 107 patient records of children with HIV infection on HAART treatment protocols was conducted. Four patients were identified who responded to protease inhibitor-containing HAART therapy with sustained viral load suppression, and stable immunologic and medical parameters, yet demonstrated significant cognitive decline. Such discordance between biological and clinical markers previously has been reported in adults with HIV disease but not in children. This observed decline in neurocognitive functioning despite stable medical parameters suggests that HAART regimens that are effective for systemic disease may not be as effective for the central nervous system (CNS), perhaps because the antiretrovirals do not penetrate adequately into the CNS. Of note, 3 of these 4 patients did not have zidovudine (ZDV) included in their HAART regimen. The only patient who was treated with ZDV containing regimen received 90 mg/m(2) every 6 hours, which is at the lower end of the recommended ZDV pediatric full-dose range (90 mg/m(2) to 120 mg/m(2)). Two of the 4 patients began ZDV at 120 mg/m(2) every 6 hours following the decline in their cognitive test scores and subsequently showed improved or stable functioning as evidenced by the results of follow-up psychometric testing. Long-term prospective studies using both systemic and CNS measures are necessary to further investigate the effects of HAART in children with HIV disease. Longitudinal cognitive assessments of children receiving HAART appear indicated to identify cognitive decline and to provide appropriate therapeutic intervention when manifestations of HIV-related CNS disease progression occur.

Psychological aspects of HIV infection in children

Despite advances in the pharmaceutical treatment of HIV disease, there are still an increasing number of people living with the disease, and an increasing number of children and adolescents are personally affected by the epidemic. The psychological effects on these children are significant and relate not only to a parent's degree of illness and the threat of death but also to the association of the disease with substance abuse and the pervasive effects of the stigma that surround it. To intervene optimally on behalf of these children, programs must be multidisciplinary and take a holistic approach to address specific social and psychological issues and ensure stability in a child's care giving.

Neurologic aspects of HIV infection in infants and children: therapeutic approaches and outcome

Central nervous system (CNS) HIV-related disorders frequently have devastating consequences. Significant progress has been made in the early diagnosis and treatment of the HIV-infected patient. As a result, the prevalence and natural history of neurologic illnesses have changed. This paper reviews the epidemiology, clinical manifestations, and neuropathogenesis of HIV-related CNS disorders. Advances in antiretroviral therapy, neuroprophylaxis, and neuroprotective strategies are also discussed.

Low blood CD8+ T-lymphocytes and high circulating monocytes are predictors of HIV-1-associated progressive encephalopathy in children

OBJECTIVE

Human immunodeficiency virus type 1 (HIV-1)-associated progressive encephalopathy (PE) is a common and devastating complication of HIV-1 infection in children, whose risk factors have not yet been clearly defined. Regardless of the age of presentation, PE shortens life expectancy. Paradoxically, as survival of patients has been prolonged as a result of the use of antiretroviral therapy, the prevalence of PE has increased. Therefore, a predictive marker of PE emergence is critical. The objective of this study was to determine in an observational study whether any immunologic (CD4(+) and CD8(+) T-lymphocyte counts, monocyte counts) or virologic (viral load [VL], biological characteristics of viral isolates) marker might be predictive of PE and whether any particular marker may be involved in the timing of clinical onset of PE.

METHODS

A total of 189 children who were vertically infected with HIV-1 were studied retrospectively, 58 of whom fulfilled criteria of the American Academy of Neurology for PE. T-lymphocyte subsets and monocytes in peripheral blood were quantified by flow cytometry. HIV-1 RNA was measured in plasma using a quantitative reverse transcriptase polymerase chain reaction assay. Demographic, clinical, and viro-immunologic characteristics in infants were compared with control groups using logistic regression. Proportions were compared using the chi(2) test or Fisher exact test. For each child, immunologic and virologic markers were analyzed in parallel closely before clinical onset of PE and closely after PE onset and compared by using the Student t test for paired samples.

RESULTS

Overall, mortality of 58 HIV-1-infected children who developed PE was significantly higher than of children who did not develop this complication. Blood CD8(+) T-lymphocytes <25% in the first months of life suggested a relative risk of progressing to PE 4-fold higher than those with CD8(+) >25% (95% confidence interval: 1.2-13.9) and remained statistically significant after adjustment for treatment. When we compared the PE-positive group with the acquired immunodeficiency syndrome (AIDS)/PE-negative group (children who developed clinical category C and without neurologic manifestations) in a cross-sectional study within 12 months before PE or AIDS diagnosis, respectively, the %CD8(+) T-lymphocytes were significantly lower in the PE-positive group. Normalized absolute counts of CD8(+) T-lymphocytes with respect to seroreverting children were significantly lower in the group of children with encephalopathy with respect to the AIDS/PE-negative group (data not shown). It is interesting that a statistically significant increase was observed in circulating monocyte percentages and absolute counts shortly before the first neurologic symptoms compared with values after PE was established and with those from HIV-1-infected controls. With respect to AIDS-related events, PE was strongly associated with anemia and lymphoid interstitial pneumonitis in the PE-positive group with respect to a group of children with AIDS but without PE.

CONCLUSION

HIV-1 infection of the central nervous system (CNS) remains an important clinical concern. The first step toward PE prevention in HIV-1-infected children should be directed at predicting risk of PE and thus the prompt and reliable identification of infants who are at risk for CNS disease progression. Low blood CD8(+) T-lymphocytes is a strong early predictive marker of PE emergence in vertical HIV-1 infection. Indeed, among all of the immunologic and virologic variables assessed in this observational study, the only significant difference during the first months of life are the CD8(+) T-lymphocytes. A peak of significantly higher peripheral monocytes before the onset of PE with respect to established PE has not been previously described, and strengthens the growing evidence that an increased traffic of monocytes to the brain may be a key factor in triggering neurologic symptoms. The suppression of HIV-1 replication is dependent on the presence of a relatively small number of HIV-1-specifof HIV-1-specific CD8(+) T-lymphocytes, and it is possible that the duration of the neurologically asymptomatic phase for any given child may depend mostly on the magnitude of specific CD8(+) T-lymphocyte responses. Thus, a decrease of CD8(+) T-lymphocytes would diminish the host capacity to control viral infection, as reported in animal models, enabling infected macrophages to cross the blood-brain barrier. Our results advocate the use of CD8(+) T-lymphocyte and monocyte counts to follow-up HIV-1-infected children. We suggest that CD8(+) T-lymphocytes may be the nexus for many different aspects of the disease, namely loss of control of HIV-1 replication determining higher VL, increased traffic of activated and/or infected monocytes, spread of infection to immune sanctuaries, and finally clinical neurologic emergence of PE. Moreover, we suggest that CD8(+) T-lymphocytes or/and monocytes may be used as putative biological markers of neuropathogenicity. This might suggest their use in decision making of when to start more effective antiretroviral regimens for HIV-1 infection of the CNS and the need of new therapies either to preserve or to augment an adequate CD8(+) T-lymphocyte immune response. Early detection of children who are at risk for developing PE is particularly important because aggressive highly active antiretroviral therapy improves neurologic symptoms, allows possible use of neuroprotective treatment to prevent further development of encephalopathy, and emphasizes the relevance of developing therapies aimed to enhance CD8(+) T-lymphocyte function. In conclusion, the surrogate markers routinely used in clinical practice for HIV-1 infection (ie, CD4(+) T-lymphocyte counts and VL) seem to be insufficient to evaluate the clinical involvement of the CNS. Other systemic markers, as the recent proposed markers for PE evolution (cerebrospinal fluid VL by lumbar puncture and brain atrophy by cerebral magnetic resonance imaging) are undoubtedly more invasive than measuring CD8(+) T-lymphocyte and monocyte counts, when the neurologic manifestations of PE are still preventable.

HIV-1 infection and AIDS

Since the initial descriptions of AIDS in the late 1970s, much has been learned about the biology of HIV-1 and the cells it infects. Much has also been learned about mother-to-infant viral transmission and the natural history of HIV-1 infection. Key studies led to strategies for interrupting mother-to-infant transmission, resulting in a significant decline in neonatal HIV-1 infection. More proficient diagnostic techniques made early diagnosis of HIV-1-infected neonates and infants possible during asymptomatic or mildly symptomatic disease stages. Major advances in treatment led to the control of viral replication and thereby altered the course of disease progression. HIV-1/AIDS-associated neurologic disorders declined in parallel. In countries where these therapies are readily available, a dramatic decline in the number of infants born HIV-1 infected has been realized as has a markedly improved survival rate of those infected. Many questions remain, however. The long-term effects of prenatal exposure to antiretroviral agents are not yet known and continue to be studied. Just exactly how HAART therapy may affect early signs of pediatric HIV-1/AIDS-associated CNS disease, should they develop, is unclear. As new anti-retroviral agents are developed and new combination drug regimens are instituted, the potential for neurologic complications, toxicities, and adverse drug interactions (e.g., with antiepileptic drugs (AEDS)) exists and needs to be identified and monitored.

Effect of combination antiretroviral therapy on cerebrospinal fluid HIV RNA, HIV resistance, and clinical manifestations of encephalopathy

OBJECTIVES

This study evaluated the effect of treatment with abacavir/lamivudine/zidovudine versus lamivudine/zidovudine on cerebrospinal fluid (CSF) human immunodeficiency virus (HIV) RNA and clinical manifestations of HIV encephalopathy in children.

STUDY DESIGN

HIV-infected children 7 months to 10 years of age (n = 23) were studied. CSF and plasma were obtained at baseline and weeks 8, 16, and 48. Genotype analysis of HIV was attempted at baseline and week 48. Neurologic evaluations were performed at baseline and weeks 16, 32, and 48.

RESULTS

At baseline, 83% of children had >2.00 log(10) copies/mL HIV RNA in CSF, but only 10% had HIV RNA measurable at week 48. Among children in whom paired genotyping of HIV was possible, 8 of 11 had identical patterns in both CSF and plasma at baseline, whereas at week 48, only 1 of 9 children had similar patterns. Neurologic abnormalities were observed in 83% of children at baseline but only 35% of children at week 48 (P =.004), suggesting a benefit of treatment.

CONCLUSIONS

Antiretroviral therapy was associated with a decline in CSF HIV RNA and an improvement in neurologic status. The development of genotypic mutations was different in CSF and plasma, suggesting discordant viral evolution. These results suggest that antiretroviral treatment in children should include agents with activity in the CNS.

Impact of human immunodeficiency virus type 1 infection on the epidemiology and outcome of bacterial meningitis in South African children

OBJECTIVE

To define the impact that the human immunodeficiency virus type 1 (HIV-1) epidemic has had on the burden and outcome of bacterial meningitis in an area with a high prevalence of pediatric HIV-1 infection.

METHODS

Children less than 12 years of age with proven or suspected bacterial meningitis were enrolled in this study between March 1997 and February 1999, and their hospital records were retrospectively reviewed for clinical data.

RESULTS

Sixty-two (42.2%) of the 147 children tested for HIV-1 infection were infected. Streptococcus pneumoniae (Pnc) exceeded Haemophilus influenzae type b (Hib) as the most important cause of meningitis in HIV-1-infected (74.2% vs. 12.9%, respectively) compared with uninfected children (29.4% vs. 42.3%, respectively, P less than 10(-5)). The estimated relative risk of Pnc meningitis was greater in HIV-1-infected than in uninfected children under 2 years of age (relative risk [RR] = 40.4; 95% confidence intervals [CI] = 17.7-92.2). Overall, HIV-1-infected children had a higher rate of mortality than uninfected children (30.6% vs. 11.8%, respectively, P = 0.01), and in particular, HIV-1-infected children with Pnc meningitis (60.8% vs. 36.0%, respectively, P = 0.04) had a poorer outcome.

CONCLUSIONS

Streptococcus pneumoniae has exceeded Hib as the most important pathogen causing bacterial meningitis in HIV-1-infected compared with uninfected children. Effective vaccination against Hib and Pnc should be evaluated to reduce the overall burden of bacterial meningitis in HIV-1-infected children.

Neurological and developmental effects of HIV and AIDS in children and adolescents

HIV-related encephalopathy is an important problem in vertically infected children with HIV. Infected infants may manifest early, catastrophic encephalopathy, with loss of brain growth, motor abnormalities, and cognitive dysfunction. Even without evidence of AIDS, infected infants score lower than serorevertors on developmental measures, particularly language acquisition. Children with perinatal or later transfusion-related infection generally are roughly comparable developmentally to their peers until late in their course. Symptoms similar to adult AIDS dementia complex are occasionally seen in adolescents with advanced AIDS, including dementia, bradykinesia, and spasticity. Opportunistic CNS infections such as toxoplasmosis and progressive multifocal leukoencephalopathy are less common in children and adolescents than in adults. Increasing evidence suggests that aggressive antiretroviral treatment may halt or even reverse encephalopathy. Neuroimaging changes may precede or follow clinical manifestations, and include early lenticulostriate vessel echogenicity on cranial ultrasound, calcifying microangiopathy on CT scan, and/or white matter lesions and central atrophy on MRI. Differential diagnosis of neurological dysfunction in an HIV-infected infant includes the effects of maternal substance abuse, other CNS congenital infections, and other causes of early static encephalopathy. Initial entry of HIV into the nervous system occurs very early in infection. The risk of clinical HIV encephalopathy increases with very early age of infection and with high viral loads. Virus is found in microglia and brain derived macrophages, not neurons. The neuronal effect of HIV is probably indirect, with various cytokines implicated. Apoptosis is the presumed mechanism of damage to neurons by HIV.

Cardiac manifestations of HIV infection in infants and children

Cardiac manifestations of HIV infection in children are common, but etiologies, contributing factors, and the natural history are largely unexplored. The Pediatric Pulmonary and Cardiovascular Complications of Vertically Transmitted Human Immunodeficiency Virus Infection Study (P2C2 HIV Study) was initiated in 1989 by the National Heart, Lung and Blood Institute, USA. A primary objective of this study is to examine the epidemiology of cardiovascular problems associated with HIV infection in a cohort of children vertically infected. Findings of the study thus far show that cardiovascular problems associated with HIV infection including left ventricular dysfunction and increased left ventricular mass are common and clinically important indicators of survival for children infected with HIV.

Early cognitive and motor development among infants born to women infected with human immunodeficiency virus. Women and Infants Transmission Study Group

OBJECTIVE

To examine the frequency, timing, and factors associated with abnormal cognitive and motor development during the first 30 months of life in infants born to women infected with human immunodeficiency virus type 1 (HIV-1).

METHODS

Serial neurodevelopmental assessment was performed with 595 infants born to women infected with HIV-1 in a multicenter, prospective, natural history cohort study. Survival analysis methods were used to evaluate 6 outcome events related to abnormal cognitive and motor growth (time to confirmed drop of 1 SD, time to first score <69, and time to confirmed drop of 2 SD) in Bayley Scales of Infant Development Mental Developmental Index (MDI) and Psychomotor Developmental Index (PDI) scores among infected (n = 114) and uninfected (n = 481) infants. Proportional hazards modeling was used to evaluate the effects of HIV infection status, prematurity, prenatal exposure to illicit drugs, maternal educational attainment, and primary language.

RESULTS

HIV-1 infection was significantly associated with increased risk for all outcome events related to abnormal mental and motor growth. Differences between infected and uninfected infants were apparent by 4 months of age. Prematurity was associated with increased risk for MDI <69 and PDI <69. Maternal education of <9 completed years was associated with increased risk for MDI <69. Neither prenatal exposure to illicit drugs nor primary language other than English was associated with abnormal development.

CONCLUSION

A significant proportion of infants with HIV-1 infection show early and marked cognitive and motor delays or declines that may be important early indicators of HIV disease progression. These abnormalities are independent of other risk factors for developmental delay.

Organ-specific manifestations of HIV disease in children

The clinical manifestations of HIV disease in children affect multiple organ systems. The severity of each manifestation varies by organ system and can be related in many cases to multifactorial causes, namely HIV replication in affected tissue, concomitant opportunistic infection of the organ, effect of concurrent immunodeficiency or autoimmune mechanisms on the organ, or adverse end-organ drug effect (primary HIV therapy or prophylaxis regimens). More information is needed to understand the pathogenesis of the systemic effect of HIV on different organ systems, especially the CNS. Most clinicians hope that advances in therapeutic interventions for primary HIV will halt the progression of the organ-specific manifestations that have been outlined in this article, but such potent therapies will probably have their own unique and new effects on HIV-infected organ systems. Vigilance for organ-specific manifestations in the era of HAART is imperative to provide the best clinical outcome for HIV-infected children.

Neurologic, neurocognitive, and brain growth outcomes in human immunodeficiency virus-infected children receiving different nucleoside antiretroviral regimens. Pediatric AIDS Clinical Trials Group 152 Study Team

OBJECTIVES

To compare the impact of three different nucleoside reverse transcriptase inhibitor regimens, zidovudine (ZDV) monotherapy, didanosine (ddI) monotherapy, and ZDV plus ddI combination therapy, on central nervous system (CNS) outcomes in symptomatic human immunodeficiency virus (HIV)-infected children.

METHODS

Serial neurologic examinations, neurocognitive tests, and brain growth assessments (head circumference measurements and head computed tomography or magnetic resonance imaging studies) were performed in 831 infants and children who participated in a randomized double-blind clinical trial of nucleoside reverse transcriptase inhibitors. The Pediatric AIDS Clinical Trials Group study 152 conducted between 1991 and 1995 enrolled antiretroviral therapy-naive children. Subjects were stratified by age (3 to <30 months of age or 30 months to 18 years of age) and randomized in equal proportions to the three treatment groups.

RESULTS

Combination ZDV and ddI therapy was superior to either ZDV or ddI monotherapy for most of the CNS outcomes evaluated. Treatment differences were observed within both age strata. ZDV monotherapy showed a modest statistically significant improvement in cognitive performance compared with ddI monotherapy during the initial 24 weeks, but for subsequent protection against CNS deterioration no clear difference was observed between the two monotherapy arms.

CONCLUSIONS

Combination therapy with ZDV and ddI was more effective than either of the two monotherapies against CNS manifestations of human immunodeficiency virus disease. The results of this study did not indicate a long-term beneficial effect for ZDV monotherapy compared with ddI monotherapy.

Tuberculous meningitis and co-infection with HIV

The clinical, laboratory and radiological features of 30 children with clinically diagnosed tuberculous meningitis (TBM) who were HIV-seronegative were compared with those of ten HIV-infected children with TBM. Such comparative data are not currently available in the literature and so are an important addition to our knowledge of the HIV-TB co-infection epidemic. In comparison with the HIV-negative children, those infected with HIV were younger, had a shorter duration of symptoms and were more often Mantoux-negative (HIV-positive 23% vs HIV-negative 70%; p = 0.01). On presentation, all children in both groups were in MRC TBM stages II or III. Clinical features were similar in both groups but computed tomography of the brain showed more ventricular enlargement (HIV-positive 80% vs HIV-negative 63%), gyral enhancement (HIV-positive 60% vs HIV-negative 17%; p = 0.01) and cerebral atrophy (HIV-positive 40% vs HIV-negative 17%). Outcome was considerably worse in the HIV-positive children, of whom 30% died (vs HIV-negative 0/30; p = 0.01) and the remainder were moderately (HIV-positive 30% vs HIV-negative 24%) or severely (HIV-positive 30% vs HIV-negative 19%) handicapped at the end of treatment. While clinical features were not markedly different in HIV-infected and uninfected children with TBM, abnormal radiological findings were more common in the HIV-infected group and outcome was considerably worse. Co-existing HIV encephalopathy and diminished immune competence undoubtedly contributed to the more severe clinical and neuro-radiological features.