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

Neurocognitive function among HIV-infected children on protease inhibitor -based versus non-protease inhibitor based antiretroviral therapy in Uganda: a pilot study

BACKGROUND

HIV infection is associated with significant neurocognitive deficits making maximization of cognitive function among children receiving antiretroviral therapy (ART) a public health imperative. Non-protease inhibitors (non-PIs) achieve higher drug levels in the cerebral spinal fluid (CSF) compared to PIs, potentially leading to better neurocognitive function by reducing CSF viral load and inflammation. ART that maximises children's neurodevelopment and school achievement could result in improved quality of life and productivity as adults, but little research to date has examined whether non-PI ART is associated with better neurocognitive outcomes. We compared the neurocognitive function between children living with HIV receiving PI-based and non PI-based ART.

METHODS

We recruited a consecutive sample of clinically stable Ugandan children living with HIV aged 5-12 years who received PI-based or non PI-based ART for ≥ 1 year (viral load < 1000 copies). Neurocognitive function was assessed using the Kaufman Assessment Battery for Children, the Test of Variables of Attention, and Bruininks-Oseretsky Test of Motor Proficiency. Age-adjusted neurocognitive z-scores for the two groups were compared using linear regression models in STATA version 13. The Hommel's method was used to adjust for multiple testing.

RESULTS

We enrolled 76 children living with HIV; 34 on PI ART and 42 on non-PI ART. Mean (±SD) age was greater in the non-PI vs. PI group (9.5 ± 1.9 vs. 8.5 ± 2.0) years (p = 0.03). Children in the non-PI group had lower socioeconomic scores (5.7 ± 3.3 vs. 7.4 ± 2.8, p = 0.02). There was no difference in neurocognitive function between the groups (adjusted p > 0.05) for KABC and TOVA. Children in the PI group had better total BOT scores than their counterparts (46.07 ± 1.40) vs. 40.51 (1.24), p = 0.03).

CONCLUSIONS

We detected no difference in neurocognitive function among children on PI and non PI-based ART therapy based on KABC and TOVA tests. Children on PI based ART had better motor function than their counterparts. We recommend a prospective study with a larger sample size.

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.

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

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

Killer Cell Immunoglobulin-Like Receptor Alleles Alter HIV Disease in Children

BACKGROUND

HLA class I molecules are ligands for killer cell immunoglobin like receptors (KIR) that control the antiviral response of natural killer (NK) cells. However, the effects of KIR and HLA (KIR/HLA) alleles on HIV disease of children have not been studied.

METHODS

993 antiretroviral naïve children with symptomatic HIV infection from PACTG protocols P152 and P300 were genotyped for KIR and HLA alleles using the Luminex platform. Linear regression was used to test the association between genotypes and baseline pre-ART HIV RNA, CD4+ lymphocyte count, and cognitive score, adjusting for age, race/ethnicity and study. The interaction between genetic markers and age was investigated. To account for multiple testing the false discovery rate (FDR) was controlled at 0.05.

RESULTS

Children with the KIR2DS4*ALL FULL LENGTH (KIR2DS4*AFL) allele had higher CD4+ lymphocyte counts. Among children ≤2 years of age, the KIR2DS4*AFL was associated with lower plasma HIV RNA and higher cognitive index scores. KIR Cent2DS3/5_1 had lower CD4+ lymphocyte counts in children ≤2 years of age, while the presence of Tel1, Tel2DS4_2, Tel2DS4_4, Tel8, Tel2DS4_6 had higher CD4+ lymphocyte counts in all children. Presence of Cent2, Cent4 and Cent8 was associated with increased HIV RNA load in children ≤2 years. Presence of KIR3DL1+Bw4 was associated with higher CD4+ lymphocyte counts in all children. Among children >2 years old, KIR3DS1+Bw4-80I was associated with higher plasma HIV RNA, and Bw6/Bw6 was associated with lower plasma HIV RNA compared to children with KIR3DS1+Bw4-80I.

CONCLUSIONS

Presented data show for the first time that specific KIR alleles independently or combined with HLA ligands are associated with HIV RNA and CD4+ lymphocyte counts in infected, antiretroviral naive children; and many of these effect estimates appear to be age dependent. These data support a role for specific KIR alleles in HIV pathogenesis in children.

Neurodevelopmental benefits of antiretroviral therapy in Ugandan children aged 0-6 years with HIV

BACKGROUND

Insufficient data on neurodevelopmental benefits of antiretroviral therapy (ART) in children.

METHODS

Prospective study of 329 mothers and children aged 0-6 years to assess neurodevelopment. Results stratified by the maternal (M) and child (C) HIV status (MHIV⁻/CHIV⁻, MHIV⁺/CHIV⁻, and MHIV⁺/CHIV⁺). Gross Motor, Visual Reception, Fine Motor, Receptive, and Expressive Language scores were assessed by Mullen Scales of Early Learning. Global cognitive function was derived from an Early Learning Composite (ELC) score. Standardized weight and height for age z scores were constructed, and the lowest 15% cutoff defined disability. Generalized linear models were used to estimate prevalence rate ratios (PRR) adjusted for the child's age, weight, and height. In HIV-positive children, generalized linear models assessed the impact of ART initiation and duration on neurodevelopment.

RESULTS

Compared with MHIV⁻/CHIV⁻ children, HIV-positive children were more likely to have global deficits in all measures of neurodevelopment except gross motor skills, whereas in MHIV⁺/CHIV⁻ children, there was impairment in receptive language [adjusted PRR = 2.67; confidence interval (CI): 1·08 to 6.60] and the ELC (adjusted PRR = 2.94; CI: 1.11 to 7.82). Of the children born to HIV-positive mothers, HIV-positive children did worse than MHIV⁺/CHIV⁻ only in visual reception skills (adjusted PRR = 2.86; CI: 1.23 to 6.65). Of the 116 HIV-positive children, 44% had initiated ART. Compared with ART duration of <12 months, ART durations of 24-60 months were associated with decreased impairments in Fine Motor, Receptive Language, Expressive Language, and ELC scores.

CONCLUSIONS

Longer duration on ART is associated with reduction of some neurologic impairment and early diagnosis and treatment of HIV-positive children is a priority.

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

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

A pilot study to investigate the muscle strength of children infected with HIV

Background/aims

Paediatric HIV remains a significant challenge to children and caregivers in South Africa. Little is known about the effect of HIV infection on muscle strength in children, however potential decrease in muscle strength has been inferred to affect functional ability in these children. The aim of this pilot study was to compare the muscle strength of children infected with HIV who had been receiving highly active antiretroviral therapy (HAART) to that of children infected with HIV not receiving HAART.

Methods

The study population included a group of 16 children receiving HAART and 16 children not receiving HAART. A one-off test of muscle strength was undertaken using a hand-held dynamometer for the child, and a demographic questionnaire and social status index to their primary caregiver. Two-sample student t tests, Pearson correlation analyses, and backward regression analyses were used to analyse data.

Results

The cluster of differentiation (CD4) count of the group on HAART was significantly higher than the group not receiving HAART. The group not receiving HAART was stronger than the HAART group. No significant correlation was shown between length of time having received HAART and muscle strength, or between CD4 count and muscle strength in the group receiving HAART. A significant negative correlation was shown between CD4 count and muscle strength in the group not receiving HAART.

Conclusion

Further research is needed to establish the impact of earlier administration of HAART on muscle strength in children infected with HIV.

The neurodevelopment of HIV-infected infants on HAART compared to HIV-exposed but uninfected infants

The aim of this study was to compare the neurodevelopment of HIV-infected (HI) infants in combination with antiretroviral therapy also known as HAART (highly active antiretroviral therapy) to HIV-exposed uninfected (HEU) infants. Twenty-seven HIV infected and 29 HEU infants under the age of one year attending the Empilweni Clinic at Rahima Moosa Mother and Child Hospital were studied. HI infants were assessed prior to initiating HAART and then for six months whilst on HAART. Neurodevelopment was assessed using the Bayley Scales of Infant and Toddler Development, 3rd ed (Bayley III). The HI infants scored significantly lower when compared to HEU infants for motor and language development at baseline, three months and six months follow up. No significant improvement in language (p = 0.46) and motor function (p = 0.91) occurred over time; however, developmental scores did not decrease. Cognitive development in the HI group was significantly lower when compared to the HEU group at visit one (p = 0.003). By six months follow-up, there were no significant differences between the two groups for cognitive development (p = 0.18). This study suggests that HIV-positive infants are delayed when compared to HEU infants. HAART may help to prevent further delay; however, it does not reverse the neurological damage already present. There is a need for therapists to be involved in pediatric HIV clinical services in order to provide early developmental screening as well as rehabilitative services to those children in need.

Neurologic abnormalities in HIV-1 infected children in the era of combination antiretroviral therapy

Background

Pediatric HIV-1 infection is associated with neurologic abnormalities. In recent years, the neurological outcome of HIV-1 infected children has substantially improved with combination antiretroviral therapy (cART). However, data regarding the long-term effect of cART and neurologic outcome are limited.

Methods

In the Pediatric Amsterdam Cohort on HIV-1 study, 59 perinatally HIV-1 infected children were evaluated from 1992–2010. All children underwent neurological examination and neuro-imaging studies, including CT-scan and/or MRI imaging. Fisher exact and Kruskal-Wallis tests were used to compare clinical deviations of neuro-imaging studies with HIV-1 related parameters, including CD4⁺ T cell count, HIV-1 viral load in blood and cerebrospinal fluid (CSF), and duration of cART as well as neurological examination.

Results

Abnormal neurologic examinations in these HIV-1 infected children included language impairment (22%), abnormal muscle tone (hyper/hypotonia) (14%) and delay in reaching developmental milestones (12%). Ventricular enlargement and sulcal widening (29%) and white matter lesions (38%) were prominent findings. White matter lesions were positively correlated with HIV-1 viral load levels. In a small follow-up sub study white matter lesions did not improve while children with ventricular enlargement and sulcal widening showed improvements whilst being treated with cART.

Conclusions

In the current era of cART HIV-1 infected children still frequently show neurological impairments together with abnormal neuro-imaging.

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.

Language impairment in children perinatally infected with HIV compared to children who were HIV-exposed and uninfected

OBJECTIVE

To investigate the risk for language impairment (LI) in children perinatally infected or exposed to HIV.

METHODS

We evaluated the prevalence of LI in 7- to 16-year-old children with perinatal HIV infection (HIV+) compared with HIV-exposed and uninfected children, using a comprehensive standardized language test (Clinical Evaluation of Language Functioning-Fourth Edition [CELF-4]). LI was classified as primary LI (Pri-LI) (monolingual English exposure and no cognitive or hearing impairment), concurrent LI (Con-LI) (cognitive or hearing impairment), or no LI. Associations of demographic, caregiver, HIV disease, and antiretroviral treatment factors with LI category were evaluated using univariate and multivariable logistic regression models.

RESULTS

Of the 468 children with language assessments, 184 (39%) had LI. No difference was observed by HIV infection status for overall LI or for Pri-LI or Con-LI; mean (SD) CELF-4 scores were 88.5 (18.4) for HIV+ versus 87.5 (17.9) for HIV-exposed and uninfected children. After adjustment, black children had higher odds of Pri-LI versus no LI (adjusted odds ratio [aOR] = 2.43, p = .03). Children who were black, Hispanic, had a caregiver with low education or low intelligence quotient, or a nonbiological parent as caregiver had higher odds of Con-LI versus no LI. Among HIV+ children, viral load >400 copies/mL (aOR = 3.04, p < .001), Centers for Disease Control and Prevention Class C (aOR = 2.19, p = .02), and antiretroviral treatment initiation <6 months of age (aOR = 2.12, p = .02) were associated with higher odds of Con-LI versus no LI.

CONCLUSIONS

Children perinatally exposed to HIV are at high risk for LI, but such risk was not increased for youth with HIV. Risk factors differed for Pri-LI and Con-LI.

The effect of a basic home stimulation programme on the development of young children infected with HIV

AIMS

The human immunodeficiency virus (HIV) potentially causes a significant encephalopathy and resultant developmental delay in infected children. The aim of this study was to determine whether a home-based intervention programme could have an impact on the neurodevelopmental status of children infected with HIV.

METHOD

A longitudinal, randomized, controlled trial was conducted. A total of 122 children aged less than 2 years 6 months were assigned to either a comparison or an experimental group. Children in the experimental group were given a home stimulation programme that was updated every 3 months. The home programme included activities to promote motor, cognitive, and speech and language development. Children in the comparison group received no developmental intervention. Children were assessed by a blinded assessor at baseline, 6 months, and 12 months using the Bayley Scales of Infant Development, 2nd edition.

RESULTS

The children in this study came from poor socioeconomic backgrounds and their nutritional status was suboptimal. The experimental group included 60 children (30 males, 30 females) with a mean age of 18 months (SD 8.1 mo). The comparison group included 62 children (32 males, 30 females) with a mean age 19 months (SD 8.2 mo). Cognitive and motor development were severely affected at baseline, with 52% of the children having severe cognitive delay and 72% having severe motor delay at baseline. Children in the experimental group showed significantly greater improvement in cognitive (p=0.010) and motor (p=0.020) development over time than children in the comparison group.

INTERPRETATION

A home stimulation programme taught to the caregiver can significantly improve cognitive and motor development in young children infected with HIV.

Design of the silent cerebral infarct transfusion (SIT) trial

BACKGROUND

Silent cerebral infarct (SCI) is the most common cause of serious neurological disease in sickle cell anemia (SCA), affecting approximately 22% of children. The goal of this trial is to determine whether blood transfusion therapy will reduce further neurological morbidity in children with SCI, and if so, the magnitude of this benefit.

PROCEDURE

The Silent Cerebral Infarct Transfusion (SIT) Trial includes 29 clinical sites and 3 subsites, a Clinical Coordinating Center, and a Statistical and Data Coordinating Center, to test the following hypothesis: prophylactic blood transfusion therapy in children with SCI will result in at least an 86% reduction in the rate of subsequent overt strokes or new or progressive cerebral infarcts as defined by magnetic resonance imaging (MRI) of the brain. The intervention is blood transfusion versus observation. Two hundred and four participants (102 in each treatment assignment) will ensure 85% power to detect the effect necessary to recommend transfusion therapy (86% reduction), after accounting for 10% drop out and 19% crossover rates. MRI examination of the brain is done at screening, immediately before randomization and study exit. Each randomly assigned participant receives a cognitive test battery at study entry, 12-18 months later, and study exit and an annual neurological examination. Blood is obtained from all screened participants for a biologic repository containing serum and a renewable source of DNA.

CONCLUSION

The SIT Trial could lead to a change in standard care practices for children affected with SCA and SCI, with a consequent reduction in neurological morbidity.

Neurodevelopmental trajectory of HIV-infected children accessing care in Kinshasa, Democratic Republic of Congo

OBJECTIVE

To assess the effect of HIV care (including highly active antiretroviral therapy if eligible) on neurodevelopment.

DESIGN

Prospective cohort study.

METHODS

Motor and mental development of 35 HIV-infected children (aged 18-71 months) was assessed at entry into care and after 6 and 12 months using age-appropriate tools. Developmental trajectory was compared with 35 HIV-uninfected, affected, and 90 control children using linear mixed-effects models. Effects of age (29 months) and timing of entry into care (before or after highly active antiretroviral therapy eligibility) were explored in secondary analyses.

RESULTS

At baseline, HIV-infected children had the lowest, control children the highest, and HIV-uninfected affected children intermediate mean developmental scores. After 1 year of care, HIV-infected children achieved mean motor and cognitive scores that were similar to HIV uninfected, affected children although lower compared with control children. Overall, HIV-infected children experienced accelerated motor development but similar gains in cognitive development compared with control children. Exploratory analyses suggest that younger children and those presenting early may experience accelerated greater gains in development.

CONCLUSIONS

HIV-infected children accessing care experience improved motor development, and may, if care is initiated at a young age or an early stage of the disease, also experience gains in cognitive development.

Neurodevelopmental functioning in HIV-infected infants and young children before and after the introduction of protease inhibitor-based highly active antiretroviral therapy

OBJECTIVES

The purpose of this work was to examine the effects of HIV infection and the impact of highly active antiretroviral treatment with protease inhibitors on neurodevelopmental functioning during the first 3 years of life.

PATIENTS AND METHODS

Pediatric AIDS Clinical Trials Group 219/219C is a longitudinal cohort study that has enrolled HIV-infected (HIV+) and HIV-exposed but uninfected (HIV-) infants and children since 1993. Longitudinal profiles of neurodevelopmental functioning as measured by the Bayley Scales of Infant Development were compared by HIV-infection status before and after the availability of highly active antiretroviral therapy with a protease inhibitor and within infants with Bayley tests available before and after initiating protease inhibitor therapy.

RESULTS

In the pre-protease inhibitor era, mean mental and motor scores in HIV+ (n = 54) infants <1 year of age were significantly lower than those among HIV- infants (n = 221) and remained lower up to 2 years of age. After protease inhibitors became available, mean mental and motor functioning of HIV+ infants (n = 91) <1 year of age were still significantly lower than those of HIV- infants (n = 838). However, against a background of declining scores among the HIV- infants, there was evidence of limited improvement in the HIV+ infants relative to their uninfected peers. Among infants who had Bayley II evaluations before and after starting a protease inhibitor, there was a trend to improved mental and motor scores after initiation of protease inhibitor therapy.

CONCLUSIONS

The suppression of systemic viral replication and subsequent substantial improvements in survival and immunologic status brought about by highly active antiretroviral therapy have been followed by limited improvements in neurodevelopmental functioning in young children. Additional longitudinal research is needed to better understand the role of antiretroviral therapy as well as the impact of genetic and environmental factors on neurodevelopmental functioning in children affected by HIV.

Cognitive functioning in school-aged children with vertically acquired HIV infection being treated with highly active antiretroviral therapy (HAART)

In today's era of highly active antiretroviral therapy (HAART), few children with HIV-1 infection experience severe central nervous system (CNS) manifestations indicative of encephalopathy. However, little is known about the neurocognitive strengths and weaknesses of HIV-infected children treated with HAART. This cross-sectional study is the first to systematically investigate the relation between cognitive functioning and medical markers in HIV-infected children and adolescents treated with HAART with varying levels of computed tomography (CT) brain scan abnormalities. The Wechsler Intelligence Scale for Children-Third Edition was administered to 41 vertically infected children (mean age = 11.2 years) treated with HAART for at least 1 year. Other procedures at the time of testing included CT brain scans and collection of CD4 cell counts and plasma HIV1 RNA PCR. Although global cognitive functioning among participants was in the Average range, children with minimal to moderate CT brain scan abnormalities scored significantly lower than children with normal scans on composite measures of cognitive functioning and five specific subtests, especially tasks involving executive functions. Furthermore, children with worse immune status (CD4+ counts < or = 500) scored lower on subtests measuring processing speed. Viral load was unrelated to cognitive test scores. Thus, children with HIV being treated with HAART remain at risk for developing CNS disease. Findings emphasize the importance of conducting neuropsychological assessments in this population, particularly for children with cortical atrophy and absolute CD4+ cell counts < or = 500.

Feasibility Assessment of Cerebrospinal Fluid from HIV-1-Infected Children for HIV Proviral DNA and Monocyte Chemoattractant Protein 1 Alleles

The objective of the study was to assess the feasibility of measuring human immunodeficiency virus 1 (HIV-1) proviral deoxyribonucleic acid (DNA) and associated single-nucleotide polymorphism (SNP) of monocyte chemoattractant protein 1 (MCP1) in pediatric cerebrospinal fluid (CSF). The importance of HIV DNA and MCP1 SNP has been suggested to be independently important in progression to acquired immune deficiency syndrome (AIDS) and neurocognitive impairment in adults. In children, measuring both factors in the CSF may help us understand the neuropathogenic process leading to HIV-1-associated encephalopathy (HAE). Repository specimens from 27 perinatally HIV-1-infected children with HAE were assessed for HIV DNA copy by real-time polymerase chain reaction and compared with MCP1 2578G SNP mutations measured by digesting amplified 361 bp fragments. When compared with MCP1 2578G SNP, a significant number with the mutation had high HIV DNA compared with those with wild type (p < .01), with no levels detected in HIV-1-seronegative control specimens. There were six CSF specimens with enough supernatant to measure MCP1 levels by enzyme-linked immunosorbent assay, which showed high levels in those with the MCP1 2578G mutation. This study demonstrates, for the first time, that CSF HIV DNA and MCP1 SNP can be measured and could be potential tools in future clinical studies to understand the pathogenesis of pediatric HAE.

Effects of highly active antiretroviral therapy (HAART) on psychomotor performance in children with HIV disease

OBJECTIVE

This study assesses the effects of HAART on psychomotor performance of symptomatic HIV-infected children. It is one of the first studies to look at neurobehavioral functioning in children infected with HIV in resource-limited countries.

DESIGN

A longitudinal pilot study of vertically HIV-infected children at the HIV Netherlands Australia Thailand Research Collaboration Center in Bangkok, Thailand.

METHODS

A total of 34 children participated in the study of whom 16 had never received antiretroviral (ARV) therapy and were about to start HAART (Newly treated children), 7 did not receive antiretroviral therapy (Untreated children) and 11 had been treated with HAART for more than one year (HAART experienced children). All children were administered 4 psychomotor tasks at baseline and after 4 months. The Newly treated and the Untreated children were also evaluated after 12 months.

RESULTS

In general, the children performed similarly on all psychomotor tasks at baseline. After 12 months of HAART, there was a significant increase in CD4% in the Newly treated group. Overall, psychomotor performance did not change at the 4-month evaluation in all groups. At the 12-month evaluation psychomotor performance had deteriorated substantially on all tasks in both the Newly treated and the Untreated children.

CONCLUSIONS

There was no significant difference in psychomotor functioning between children newly treated, previously treated and untreated with HAART over the course of one year. Psychomotor performance deteriorated after 12 months of HAART, which provides important indications concerning the lack of benefits of HAART on psychomotor functions in children despite immunologic reconstitution. Further research with larger sample sizes is needed to confirm these findings.

Interaction between Plasmodium falciparum and human immunodeficiency virus type 1 on the central nervous system of African children

Plasmodium falciparum and human immunodeficiency virus type 1 (HIV-1) infections are common in children living in sub-Saharan Africa (SSA). Both of these pathogens affect the central nervous system (CNS). Most HIV-1 infection of children in this region is acquired from infected mothers, particularly during breast-feeding and at the time of delivery. Over a third of children infected by birth will have died before their first birthday, before overt CNS manifestations have developed. The most common manifestations of primary CNS infection include neurodevelopmental delay, impaired brain growth, motor deficits, and behavioral problems. These deficits may also result from infections, neoplasm, or stroke. Cognitive impairments become more evident if the child survives for longer, but in Africa, children rarely survive past their fifth birthday. In malaria endemic areas, severe falciparum malaria usually develops after 6 months of age, and most of the CNS manifestations are more common in children over 1 year old. About 11% of children develop neurological deficits following cerebral malaria, most of which improve within 2 years of the insult. However, up to 24% of children may have neurocognitive impairments following severe malaria. The effect of milder malaria and coincidental parasitization on cognitive function is unknown. Other comorbidities that are common in SSA, such as malnutrition or micronutrient deficiencies, may influence children's neurodevelopment. The coinfection of malaria and HIV-1 may aggravate the neurodevelopmental impairments documented in these children. However, to date there are little published data, although it may have a profound effect of children living in SSA.

Youths and HIV/AIDS: psychiatry's role in a changing epidemic

OBJECTIVE

To review the past 10 years of published research on human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) in the United States, including psychosocial and psychiatric risk factors, epidemiology, biology, neurocognitive and psychiatric sequelae, disclosure issues, prevention strategies, and biological and behavioral treatments.

METHOD

Researchers reviewed the English-language literature with a focus on child and adolescent risk factors associated with HIV/AIDS, prevention, and treatment.

RESULTS

Substantial scientific advances have occurred over the past two decades leading to decreased morbidity and mortality in the United States from AIDS-related opportunistic infections. At the same time, rates of HIV infection are increasing in teenagers, young women, and minorities, and growing numbers of youths are living with an infected family member. Understanding HIV risk behavior requires a broad theoretical framework. Comprehensive HIV prevention programs have led to reduced risk behavior among HIV-affected youths and teens at risk of infection. Biological and behavioral treatments of HIV infection continue to evolve and have led to longer life span, improved quality of life, and fewer psychiatric problems.

CONCLUSIONS

HIV/AIDS has significant mental health implications, and psychiatry can play a critical role in curbing the epidemic. With minimal effort, mental health professionals can adapt and apply the strategies that they use to treat psychiatric symptoms to prevent HIV transmission behaviors.

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.

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.

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.

Neuropsychological consequences of HIV in children

Pediatric HIV has reached epidemic proportions. In 1997, 1.1 million children younger than 15 were living with HIV or AIDS. The virus affects children cognitively and developmentally due to the immaturity of their nervous systems and immune systems. Studies in the area of neuropsychological deficits are as yet limited in number and less well developed than studies on adult HIV. However, despite methodological weaknesses, the literature has proven conclusively that pediatric HIV affects children cognitively, developmentally, emotionally, psychologically, behaviorally, and educationally. Although treatments are allowing these children to live longer, the effects of the virus remain, requiring special care. This review examines the mechanisms behind HIV in children, the neuropsychological findings to date, and the limitations of this work. Possible useful future approaches in understanding the neuropsychological course of the disorder, as well as directions for treatment and prevention are addressed.

The efficacy of potent anti-retroviral drug combinations tested in a murine model of HIV-1 encephalitis

Development of anti-retroviral regimens with enhanced efficacy against brain HIV-1 is essential if viral eradication is to be achieved. To address this, a severe combined immune deficiency mouse model of HIV-1 encephalitis was used to assay the effect of protease-containing and protease-sparing drug regimens on viral replication in brain macrophages. Here, HIV-1-infected human monocyte-derived macrophages (MDM) are inoculated into basal ganglia, causing a multinucleated giant cell encephalitis reminiscent of human disease. Drugs were administered at the time of MDM inoculation and continued until sacrifice. Immunohistochemical tests evaluated ongoing viral replication, glial immunity, and neuronal survival. Treatment with ddI/d4T decreased the numbers of infected cells by 75%, while ddI/d4T/amprenavir or ZDV/3TC/ABC diminished infection by 98%. Triple drug regimens decreased astrogliosis by > or = 25%. This small-animal model may be used to screen drug regimens that affect ongoing HIV-1 replication within its brain sanctuary.

HIV-1-associated central nervous system dysfunction

Despite more than 15 years of extensive investigative efforts, a complete understanding of the neurological consequences of HIV-1 CNS infection remains elusive. Although the resources of numerous investigators have been focused on studies of HIV-1-associated CNS disease, the complex nature of the disease processes that underlie the clinical, pathological, and cellular manifestations of HIV-1 CNS infection have required a larger volume of studies than was initially envisioned. Several major areas remain as the focus of current research efforts. One of the more pressing issues facing researchers and clinicians alike is the search for correlates to the development of HIV-1-associated CNS neuropathology and the onset of HIVD. Although numerous parameters have been studied, none have been shown to be absolute predictors or markers of HIV-1-related CNS dysfunction. The identification of solid correlates of HIVD is an important goal that would permit clinical identification of individuals at risk for developing potentially crippling, life-threatening CNS abnormalities and would facilitate early treatment of nascent neurological problems. A more complete comprehension of the cellular foundations of CNS dysfunction and HIVD is also a fundamental part of strategies designed to treat or prevent HIV-1-associated CNS disease. Future investigations will strive to expand the body of knowledge concerning the complex interactions between infected and uninfected neuroglial cells and the roles of numerous cytokines, chemokines, and other soluble agents that are deregulated during HIV-1 CNS infection. In particular, a thorough understanding of the mechanisms of neurotoxicity may facilitate the development of new therapies that alleviate or eliminate the clinical consequences of CNS infection. Finally, investigators will continue to study HIVD within the context of single and combination drug therapies used in the treatment of HIV-1 infection and AIDS. As newer and more effective systemic treatments for HIV-1 infection and AIDS are introduced, the effects of these treatments on the onset, incidence, and severity of HIVD will also require intensive study. The impact of drug therapies on the ability of the CNS to act as an HIV-1 reservoir will also need to be addressed. Introduction of each new drug or drug combination will necessitate studies of drug penetration into the CNS and efficacy against the development of CNS abnormalities. Furthermore, as more effective treatments prolong the lifespan of individuals infected with HIV-1, the impact of extended survival on the occurrence and severity of HIVD will also require further investigations. The quest for answers to these and other questions will be complicated by the diversity of experimental systems used to study different aspects of HIV-1 CNS infection and HIVD. Each system has its own unique strengths and weaknesses. Clinical observations provide a continuous spectrum of symptomatic findings but reveal little about the underlying mechanisms of disease. In vivo imaging techniques, such as CT and MRI, also provide a continuum of observations, but the images are limited in their resolution. Neuropathological examinations of postmortem HIV-1-infected brains offer gross, cellular, and molecular views (including phenotypic and genotypic analyses of CNS viral isolates) of the diseased brain, but only provide a snapshot of the end-stage neurologic dysfunction. Studies that rely on animal surrogates for HIV-1, including SIV, simian-HIV (SHIV), feline immunodeficiency virus (FIV), visna virus, and HIV-1 SCID-hu models, permit experimental protocols that cannot be carried out in humans, but are limited by the fidelity with which each virus and animal model emulates the conditions and events observed in the human host. Finally, in vitro techniques, which include the use of primary cells and cell lines, adult or fetal human cell cultures, and BBB barrier model systems, are also convenient means by which aspe