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

Comorbid disease in children and adolescents with perinatal HIV infection: A pilot study

Background. With the increased use of combination antiretroviral therapy, the mortality of people living with HIV has decreased significantly, which has led to an increase of comorbidity and secondary HIV-related pathology in both adults and also in children and adolescents living with HIV infection. The incidence of children and adolescents with HIV infection and those in the general population varies significantly.The aim. To assess the frequency and range of chronic comorbidities in children and adolescents with perinatal HIV infection Methods. We carried out an observational study. Data on the incidence of 161 children with perinatal HIV infection registered in the Irkutsk Regional AIDS Center were copied.Results. Overall incidence of tuberculosis (18633.5 per 100 000 children), diseases of the digestive system (24844.7 per 100 000 children), diseases of the eye and adnexa (28571.4 per 100 000 children), diseases of the nervous system (18012.4 per 100 000 children), mental and behavioral disorders (13,664.6 per 100 000 children) in children with perinatal HIV infection is the higher than in children of comparable age. The overall incidence values of the endocrine system diseases, eating and metabolic disorders, diseases of the ear and mastoid process, diseases of the circulatory system, diseases of the genitourinary system, as well as congenital disorders and chromosomal disorders in children and adolescents with and without perinatal HIV infection are comparable.Conclusion. The prevalence of diseases of the circulatory, respiratory and genitourinary systems in children with perinatal HIV infection is comparable to that in the corresponding population. Prevalence of tuberculosis, anemia, diseases of the gastrointestinal tract, diseases of the eye and adnexa, diseases of the nervous system, mental and behavioral disorders is higher compared to children not exposed to HIV.

HIV encephalopathy with bilateral lower limb spasticity: gross motor function and antiretroviral therapy

AIM

To describe gross motor function in children with bilateral lower limb (BLL) spasticity due to human immunodeficiency virus encephalopathy (HIVE), and to investigate the association between age, CD4 percentage, and viral load at initiation of antiretroviral therapy (ART) and current gross motor function.

METHOD

Thirty ambulant children with HIVE and BLL spasticity were recruited. Clinical parameters, including ART, were obtained from medical records. Gross motor function was assessed using the 88-item Gross Motor Function Measure (GMFM-88).

RESULTS

The participant group was comprised of 14 males and 16 females (median age 8y; interquartile range [IQR] 7-11y). ART was initiated at a median age of 7 months (IQR 5-11mo) with a median CD4 percentage of 4.7% (IQR 2.3-8.0) and viral load of log₁₀ 6.0 (IQR 5.6-6.4). The median total GMFM-88 score was 89% (IQR 78-94%), with a wide range of scores in the 'Standing' domain (26-97%) and 'Walking, Running, and Jumping' domain (8-99%). No associations were detected between age at initiation of ART, CD4 percentage, or viral load and total GMFM-88 score.

INTERPRETATION

Limitations in gross motor function in children with HIVE and BLL spasticity range from mild to severe. ART initiation factors were not able to predict functional status in this sample.

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.

Correlates of age at attainment of developmental milestones in HIV-infected infants receiving early antiretroviral therapy

BACKGROUND

Infant HIV-1 infection is associated with impaired neurologic and motor development. Antiretroviral therapy (ART) has the potential to improve developmental outcomes but the relative contributions of pre-ART disease status, growth, treatment regimen and ART response during infancy are unknown.

METHODS

Kenyan ART-naive infants <5-months old initiated ART and had monthly assessment of age of full neck control, unsupported walking and monosyllabic speech during 24 months of follow-up. Pre-ART and post-ART correlates of age at milestone attainment were evaluated using t tests or multivariate linear regression.

RESULTS

Among 99 infants, pre-ART correlates of later milestone attainment included: underweight and stunted (neck control, walking and speech, all P values <0.05), missed prevention of mother-to-child transmission (P = 0.04) (neck control), previous hospitalization, World Health Organization (WHO) Stage III/IV, low CD4 count, and wasting (speech and walking, all P values <0.05), and low maternal CD4 (speech, P = 0.04). Infants initiated ART at a median of 14 days following enrollment. Infants receiving nevirapinevs lopinavir/ritonavir-based ART attained later speech (18.1 vs. 15.5 months, P = 0.003) [corrected]. Adjusting for pre-ART level, lower 6-month gain in CD4% was associated with later walking (0.18 months earlier per unit increase in CD4%; P = 0.004) and speech (0.12 months earlier per unit increase in CD4%; P = 0.05), and lower 6-month gains in weight-for-age (P = 0.009), height-for-age (P = 0.03) and weight-for-height (P = 0.02) were associated with later walking.

CONCLUSION

In HIV-infected infants, compromised pre-ART immune and growth status, poor post-ART immune and growth responses, and use of nevirapine- vs. lopinavir/ritonavir-based ART were each associated with later milestone attainment [corrected]. The long-term consequences of these delays are unknown.

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

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

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.

[Treatment failure in children infected with HIV in routine follow-up in a resource-limited setting in Cameroon]

Introduction

L'objectif de cette étude était de déterminer les facteurs associés aux échecs thérapeutiques chez les enfants infectés par le VIH à l'Hôpital Laquintinie de Douala.

Méthodes

Une étude transversale rétrospective a été menée sur une période de 5 mois en 2010, recrutant 222 enfants âgés de 1 à 18 ans et sous TARV depuis au moins 24 semaines. Les données sociodémographiques, cliniques, biologiques et de l'observance thérapeutique des patients ont été collectés à partir des dossiers des patients, et analysées avec le logiciel SPSS (version 16).

Résultats

39 (17,6%) des enfants étaient en échec thérapeutique (délai moyen de survenue 26,8 mois) et 73,4% d'entre eux sont passés en seconde ligne. Les garçons avaient en moyenne un risque 5 fois plus élevé de faire un échec thérapeutique que les filles (OR=3,9; p=0,035). 94,4% des enfants suivis avaient un faible taux de CD4 à l'initiation (‘ 25%) associé au risque élevé d’échec thérapeutique (OR=5,2; p=0,007). Les enfants issus de famille monoparentale représentaient près de la moitié des cas d’échecs thérapeutiques. Sur 39 cas en échec thérapeutique, 41% des enfants étaient des orphelins. Parmi les enfants sous TARV, 46% prenaient leur trithérapie sous forme de médicaments séparés parmi lesquels 52,1% étaient en échec thérapeutique.

Conclusion

Les échecs thérapeutiques et le passage en seconde ligne dépendaient du contexte familial des enfants, de leur statut immunologique à l'initiation du traitement, de leur sexe et de la forme galénique du TARV.

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.

HIV-1 alters neural and glial progenitor cell dynamics in the central nervous system: coordinated response to opiates during maturation

HIV-associated neurocognitive disorders (HANDs) are common sequelae of human immunodeficiency virus (HIV) infection, even when viral titers are well controlled by antiretroviral therapy. Evidence in patients and animal models suggests that neurologic deficits are increased during chronic opiate exposure. We have hypothesized that central nervous system (CNS) progenitor cells in both adult and developing CNS are affected by HIV infection and that opiates exacerbate these effects. To examine this question, neural progenitors were exposed to HIV-1 Tat(1-86) in the developing brain of inducible transgenic mice and in vitro. We examined whether Tat affected the proliferation or balance of progenitor populations expressing nestin, Sox2, and Olig2. Disease relevance was further tested by exposing human-derived progenitors to supernatant from HIV-1 infected monocytes. Studies concentrated on striatum, a region preferentially targeted by HIV and opiates. Results were similar among experimental paradigms. Tat or HIV exposure reduced the proliferation of undifferentiated (Sox2(+)) progenitors and oligodendroglial (Olig2(+)) progenitors. Coexposure to morphine exacerbated the effects of Tat or HIV-1(SF162) supernatant, but partially reversed HIV-1(IIIB) supernatant effects. Populations of Sox2(+) and Olig2(+) cells were also reduced by Tat exposure, although progenitor survival was unaffected. In rare instances, p24 immunolabeling was detected in viable human progenitors by confocal imaging. The vulnerability of progenitors is likely to distort the dynamic balance among neuron/glial populations as the brain matures, perhaps contributing to reports that neurologic disease is especially prevalent in pediatric HIV patients. Pediatric disease is atypical in developed regions but remains a serious concern in resource-limited areas where infection occurs commonly at birth and through breast feeding.

Paediatric HIV--trends & challenges

With the availability of antiretroviral therapy (ART), HIV infection, which was once considered a progressively fatal illness, has now become a chronic treatable condition in children, as in adults. However, the challenges these children are forced to face are far more daunting. The most significant shortcoming in the response to paediatric HIV remains the woefully inadequate prevention of mother-to-child transmission (PMTCT), allowing a large number of children to be born with HIV in the first place, in spite of it being largely preventable. In the west, mother-to-child transmission has been virtually eliminated; however, in resource-limited settings where >95 per cent of all vertical transmissions take place, still an infected infants continue to be born. There are several barriers to efficient management: delayed infant diagnosis, lack of appropriate paediatric formulations, lack of skilled health personnel, etc. Poorly developed immunity allows greater dissemination throughout various organs. There is an increased frequency of malnutrition and infections that may be more persistent, severe and less responsive to treatment. In addition, these growing children are left with inescapable challenges of facing not only lifelong adherence with complex treatment regimens, but also enormous psychosocial, mental and neuro-cognitive issues. These unique challenges must be recognized and understood in order to provide appropriate holistic management enabling them to become productive citizens of tomorrow. To address these multi-factorial issues, there is an urgent need for a concerted, sustainable and multi-pronged national and global response.

Poor health-related quality of life and abnormal psychosocial adjustment in Italian children with perinatal HIV infection receiving highly active antiretroviral treatment

To evaluate health-related quality of life (HRQL), social competence, and behavioral problems in children with perinatal HIV infection receiving highly active antiretroviral therapy (HAART), a cross-sectional study was performed at the Department of Pediatrics, University of Brescia. We evaluated HRQL, social competence, and behavioral problems in 27 HIV-infected children compared with age and sex-matched control subjects using the Pediatric Quality of Life Inventory (PedsQL) and the Child Behavior Checklist (CBCL), respectively. On the PedsQL 4.0 Generic Core Scale, HIV-infected subjects displayed significantly reduced physical (p=0.043) and psychosocial health (p=0.021) functioning, particularly at school (p=0.000), compared with healthy subjects, resulting in a significantly reduced total score (p=0.013). Assessment of social competence and the behavioral features of HIV-infected children by means of the CBCL revealed severe limitations of functioning in HIV-infected children who had impaired social ability. Children with HIV-RNA above the threshold level of 50 had higher scores on the CBCL delinquent behavior (p=0.021) and school competence (p=0.025) subsets. Although the introduction of HAART regimens has prolonged the survival of HIV-infected children, other factors, including disease morbidity and familial and environmental conditions, negatively affect their quality of life, thereby contributing to increased risk for behavioral problems.

Addison's disease and severe encephalopathy in an infant with HIV infection

AIM

To discuss the overlapping clinical spectrum of encephalopathy due to Addison's disease and HIV infection.

PATIENT

We report a 2.5-year-old boy from Uzbekistan with recurrent episodes of encephalopathy and seizures, triggered by infection or vaccinations, in whom adrenal insufficiency and infection with HIV and HCV was diagnosed. Presumably, Addisonian crises prompted hypovolemic shock and blood transfusions, which were responsible for horizontal HIV infection. The combination of adrenal insufficiency and HIV infection eventually led to progressive severe encephalopathy. Despite highly active antiretroviral therapy (which led to substantial reduction of blood viral load), the neurological condition did not improve.

DISCUSSION

The interactions of Addison's disease and HIV in the pathogenesis of encephalopathy are discussed.

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.

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.

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.

Enhancement of human immunodeficiency virus (HIV)-specific CD8+ T cells in cerebrospinal fluid compared to those in blood among antiretroviral therapy-naive HIV-positive subjects

During untreated human immunodeficiency virus type 1 (HIV-1) infection, virus-specific CD8(+) T cells partially control HIV replication in peripheral lymphoid tissues, but host mechanisms of HIV control in the central nervous system (CNS) are incompletely understood. We characterized HIV-specific CD8(+) T cells in cerebrospinal fluid (CSF) and peripheral blood among seven HIV-positive antiretroviral therapy-naïve subjects. All had grossly normal brain magnetic resonance imaging and spectroscopy and normal neuropsychometric testing. Frequencies of epitope-specific CD8(+) T cells by direct tetramer staining were on average 2.4-fold higher in CSF than in blood (P = 0.0004), while HIV RNA concentrations were lower. Cells from CSF were readily expanded ex vivo and responded to a broader range of HIV-specific human leukocyte antigen class I restricted optimal peptides than did expanded cells from blood. HIV-specific CD8(+) T cells, in contrast to total CD8(+) T cells, in CSF and blood were at comparable maturation states, as assessed by CD45RO and CCR7 staining. The strong relationship between higher T-cell frequencies and lower levels of viral antigen in CSF could be the result of increased migration to and/or preferential expansion of HIV-specific T cells within the CNS. This suggests an important role for HIV-specific CD8(+) T cells in control of intrathecal viral replication.

Neurocognitive function profile in HIV-infected school-age children

OBJECTIVES

Evaluation of neurocognitive function of school-age children with HIV.

DESIGN

Cross-sectional observational study.

METHODS

Twenty-two children (median age 9.46 years) with perinatally acquired HIV infection were administered a global intelligence test and tests from the Amsterdam Neuropsychological Tasks (ANT) program. The relationship between various patient-, disease- and treatment factors and neurocognitive outcome variables was examined.

RESULTS

Compared with age-appropriate norms, mean IQ of the HIV-infected children was in the average range. However, the HIV-infected children performed poorer on several neuropsychological tests compared with age-appropriate norms. Executive function (attentional flexibility, visuospatial working memory) and processing speed emerged as the most sensitive cognitive measures in relation to HIV disease. The correlational analyses resulted in only two significant outcomes, showing that higher CD4% at initiation of highly active antiretroviral therapy (HAART) and longer treatment duration were associated with better working memory function and attentional control, respectively.

CONCLUSIONS

These exploratory data suggest that subtle neurocognitive impairments may exist in HIV-infected school-age children, in particular characterized by compromised executive function and slowed information processing. Further research with larger sample sizes is needed to confirm these findings.

Factors influencing cerebrospinal fluid and plasma HIV-1 RNA detection rate in patients with and without opportunistic neurological disease during the HAART era

Background

In the central nervous system, HIV replication can occur relatively independent of systemic infection, and intrathecal replication of HIV-1 has been observed in patients with HIV-related and opportunistic neurological diseases. The clinical usefulness of HIV-1 RNA detection in the cerebrospinal fluid (CSF) of patients with opportunistic neurological diseases, or the effect of opportunistic diseases on CSF HIV levels in patients under HAART has not been well defined. We quantified CSF and plasma viral load in HIV-infected patients with and without different active opportunistic neurological diseases, determined the characteristics that led to a higher detection rate of HIV RNA in CSF, and compared these two compartments.

Methods

A prospective study was conducted on 90 HIV-infected patients submitted to lumbar puncture as part of a work-up for suspected neurological disease. Seventy-one patients had active neurological diseases while the remaining 19 did not.

Results

HIV-1 RNA was quantified in 90 CSF and 70 plasma samples. The HIV-1 RNA detection rate in CSF was higher in patients with neurological diseases, in those with a CD4 count lower than 200 cells/mm³, and in those not receiving antiretroviral therapy, as well as in patients with detectable plasma HIV-1 RNA. Median viral load was lower in CSF than in plasma in the total population, in patients without neurological diseases, and in patients with toxoplasmic encephalitis, while no significant difference between the two compartments was observed for patients with cryptococcal meningitis and HIV-associated dementia. CSF viral load was lower in patients with cryptococcal meningitis and neurotoxoplasmosis under HAART than in those not receiving HAART.

Conclusion

Detection of HIV-1 RNA in CSF was more frequent in patients with neurological disease, a CD4 count lower than 200 cells/mm³ and detectable plasma HIV-1. Median HIV-1 RNA levels were generally lower in CSF than in plasma but some patients showed higher CSF levels, and no difference between these two compartments was observed in patients with cryptococcal meningitis and HIV-associated dementia, suggesting the presence of intrathecal viral replication in these patients. HAART played a role in the control of CSF HIV levels even in patients with cryptococcal meningitis and neurotoxoplasmosis in whom viral replication is potentially higher.

P-glycoprotein-mediated active efflux of the anti-HIV1 nucleoside abacavir limits cellular accumulation and brain distribution

P-glycoprotein (P-gp)-mediated efflux at the blood-brain barrier has been implicated in limiting the brain distribution of many anti-HIV1 drugs, primarily protease inhibitors, resulting in suboptimal concentrations in this important sanctuary site. The objective of this study was to characterize the interaction of abacavir with P-gp and determine whether P-gp is an important mechanism in limiting abacavir delivery to the central nervous system (CNS). In vitro and in vivo techniques were employed to characterize this interaction. Abacavir stimulated P-gp ATPase activity at high concentrations. The cellular accumulation of abacavir was significantly decreased by approximately 70% in Madin-Darby canine kidney II (MDCKII)-MDR1 monolayers compared with wild-type cells and was completely restored by the P-gp inhibitors ((R)-4-((1aR,6R,10bS)-1,2-difluoro-1,1a,6,10b-tetrahydrodibenzo(a,e)cyclopropa(c)cycloheptan-6-yl)-alpha-((5-quinoloyloxy)methyl)-1-piperazineethanol, trihydrochloride) (LY335979) and N-[4-[2-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)ethyl]phenyl]-5-methoxy-9-oxo-10H-acridine-4-carboxamide (GF120918). Directional flux experiments indicated that abacavir had greater permeability in the basolateral-to-apical direction (1.58E-05 cm/s) than in the apical-to-basolateral direction (3.44E-06 cm/s) in MDR1-transfected monolayers. The directionality in net flux was abolished by both LY335979 and GF120918. In vivo brain distribution studies showed that the AUC(plasma) in mdr1a(-/-) CF-1 mutant mice was approximately 2-fold greater than the AUC(plasma) in the wild type, whereas the AUC(brain) in the mutant was 20-fold higher than that in the wild type. Therefore, the CNS drug targeting index, defined as the ratio of AUC brain-to-plasma for mutant over wild type, was greater than 10. These data are the first in vitro and in vivo evidence that a nucleoside reverse transcriptase inhibitor is a P-gp substrate. The remarkable increase in abacavir brain distribution in P-gp-deficient mutant mice over wild-type mice suggests that P-gp may play a significant role in restricting the abacavir distribution to the CNS.

HIV suppression by HAART preserves cognitive function in advanced, immune-reconstituted AIDS patients

INTRODUCTION

HIV can damage neurons leading to cognitive impairment. Epidemiological observations suggest that neuropsychological impairment might progress despite successful HAART therapy, but available prevalence estimates are based on populations that were selected for impairment.

METHODS

Of 433 advanced AIDS patients with documented immune reconstitution (CD4 lymphocyte counts < 50 before and > 100 cells/microl after HAART), 286 had brief assessments of cognition (Trailmaking A/B and Digit Symbol Tests) at least once, no confounding neurological conditions, and available neuropsychological norms with comprehensive demographic corrections. At entry, most were immune reconstituted on HAART (median CD4 cell count 230 cells/microl) and HIV was suppressed (65% < 500; only 14% > 20 000 RNA copies/ml).

RESULTS

Over one quarter (27%) of participants exhibited impairment at their initial neuropsychological assessment, a rate nearly twice that expected in a normal (HIV-uninfected) reference population (14%). These impaired participants did not differ from the unimpaired group with respect to age, sex, education, race, CD4 lymphocyte counts, or HIV-RNA levels. Improved performance on neuropsychological tests was documented over a 2-year period 3-5 years after initiating HAART. This improvement was marginally associated with the continued or improving control of plasma HIV-RNA levels, but not with concurrent levels of immune recovery (CD4 lymphocyte counts).

CONCLUSION

Most advanced AIDS patients responding to HAART for prolonged periods have stable or improving cognition, but remain more likely to be impaired than the general population. During HAART, improving test performance probably reflects both practice effects and continuing neurological recovery after more than 3 years of HAART.

Factors in AIDS dementia complex trial design: results and lessons from the abacavir trial

Objectives:

To determine the efficacy of adding abacavir (Ziagen, ABC) to optimal stable background antiretroviral therapy (SBG) to AIDS dementia complex (ADC) patients and address trial design.

Design:

Phase III randomized, double-blind placebo-controlled trial.

Setting:

Tertiary outpatient clinics.

Participants:

ADC patients on SBG for ≥8 wk.

Interventions:

Participants were randomized to ABC or matched placebo for 12 wk.

Outcome Measures:

The primary outcome measure was the change in the summary neuropsychological Z score (NPZ). Secondary measures were HIV RNA and the immune activation markers β-2 microglobulin, soluble tumor necrosis factor (TNF) receptor 2, and quinolinic acid.

Results:

105 participants were enrolled. The median change in NPZ at week 12 was +0.76 for the ABC + SBG and +0.63 for the SBG groups (p = 0.735). The lack of efficacy was unlikely related to possible limited antiviral efficacy of ABC: at week 12 more ABC than placebo participants had plasma HIV RNA ≤400 copies/mL (p = 0.002). There were, however, other factors. Two thirds of patients were subsequently found to have had baseline resistance to ABC. Second, there was an unanticipated beneficial effect of SBG that extended beyond 8 wk to 5 mo, thereby rendering some of the patients at baseline unstable. Third, there was an unexpectedly large variability in neuropsychological performance that underpowered the study. Fourth, there was a relative lack of activity of ADC: 56% of all patients had baseline cerebrospinal fluid (CSF) HIV-1 RNA <100 copies/mL and 83% had CSF β-2 microglobulin <3 nmol/L at baseline.

Conclusions:

The addition of ABC to SBG for ADC patients was not efficacious, possibly because of the inefficacy of ABC per se, baseline drug resistance, prolonged benefit from existing therapy, difficulties with sample size calculations, and lack of disease activity. Assessment of these trial design factors is critical in the design of future ADC trials.

Background: AIDS dementia complex (ADC) was first identified early in the HIV epidemic and at that time affected a substantial proportion of patients with AIDS. Patients with ADC experience dementia as well as disordered behavior and problems with movement and balance. ADC is now much less common in locations where patients have access to HAART (highly active antiretroviral therapy), consisting of combinations of several drugs that attack the virus at different stages of its life cycle. At present, however, there are no generally accepted guidelines for the best treatment of people with ADC. It has been thought for some time that the best treatment regimens for people with ADC would include drugs that cross the barrier between blood and brain well. Shortly following the introduction of HAART, a trial was carried out to find out whether adding one particular drug, abacavir, to existing combinations of drugs would be beneficial in people with ADC. This drug is known to cross the barrier between the blood and brain. The trial enrolled HIV-positive individuals with mild to moderate ADC and who were already receiving antiretroviral drug treatment. 105 participants were assigned at random to receive either high-dose abacavir or a placebo, in addition to their existing therapy. The primary outcome of the trial was a summary of performance on a set of different tests, designed to evaluate cognitive, behavior, and movement skills, at 12 weeks. Other outcomes included levels of HIV RNA (viral load) in fluid around the brain, as well as other neurological evaluations, and the level of HIV RNA and CD4⁺ T cells (the cells infected by HIV) in blood.

What this trial shows: When comparing the change in performance scores for individuals randomized to either abacavir or placebo, the results showed an improvement in scores for both groups, but no significant difference in improvement between the two groups. Similarly, the levels of HIV RNA in the cerebrospinal fluid did not differ between the two groups being compared, and other neurological tests did not show any differences between the two groups. However, at 12 weeks, patients receiving abacavir were more likely to have low levels of HIV RNA in their blood, suggesting that abacavir was active against the virus, but this did not translate into an additional improvement of these patients' dementia. The overall rates of adverse events were roughly comparable between the two groups in the trial, although participants receiving abacavir were more likely to experience certain types of events, such as nausea.

Strengths and limitations: The trial was appropriately randomized and controlled, using central telephone procedures for randomizing participants and subsequent blinding of patients and trial investigators. These procedures help minimize the chance of bias in assigning participants to the different arms as well as in the subsequent performance of individuals within the trial and the assessment of their outcomes. Limitations in the study design have been identified. One limitation is that individuals enrolled into the trial may not in fact have been receiving their existing HAART regimen for long enough to experience its optimal effect, and therefore the improvement seen in both groups could have resulted from an ongoing response to their existing regimen. It is also possible that patients improved in their test scores over the course of the trial simply because they became more familiar with the tests and not because their condition improved. This is a problem in all such trials that try to improve mental function. Finally, a limitation may have been the inclusion of patients who did not have active disease leading to worsening dementia.

Contribution to the evidence: The findings from this trial suggest that adding high-dose abacavir to existing HAART is not beneficial for patients with ADC. However, the trial provides several insights into the way that future studies of this type can be done, and which typically pose a number of challenging design problems. In particular, sensitive markers are needed that will allow researchers to monitor progression of ADC and patients' response to therapy.

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.

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.

Correlation between SIV Tat evolution and AIDS progression in cerebrospinal fluid of morphine-dependent and control macaques infected with SIV and SHIV

Morphine abuse has been associated with higher virus replication and accelerated disease progression in a non-human primate model of AIDS. In our previous report, we have shown that 50% of morphine-addicted macaques progress rapidly and that 2/3 of the rapid progressors exhibit severe neuropathogenesis. In this report, we examined the sequence evolution of the SIV Tat protein, known to participate in AIDS neuropathology, in the cerebrospinal fluid (CSF) of morphine-dependent and control macaques over the first 20 weeks of infection. The CSF SIV Tat evolution was found to be inversely related with disease progression, and the highly neuropathogenic inoculum clone sequence was the prevalent CSF form in rapid progressors. Divergence from the inoculum clone was significantly greater in both morphine-dependent normal progressors and control macaques than in the morphine-dependent rapid progressors. Furthermore, we also found evidence of a trend that morphine alters the type of mutation, resulting in an enhanced ratio of transitions to transversions (Ts:Tv). Rapid disease exacerbates this trend and appears to influence the distribution of nonsynonymous changes in the first exon of SIV tat, with a clear majority of mutations occurring in the C-terminal half of the protein where the known functionally important domains reside. Thus, morphine abuse may change the nature and extent of mutations that drive viral evolution.

HIV-1 encephalopathy among perinatally infected children: Neuropathogenesis and response to highly active antiretroviral therapy

HIV-1 encephalopathy among perinatally infected children in the United States was initially defined by a classic triad of findings that included: (1) developmental delay, (2) secondary or acquired microcephaly, and (3) pyramidal tract neuromotor deficits. The most severe form of this disorder typically occurred among young children who developed rapidly progressive disease in concert with profound immunosuppression, and Pneumocystis jiroveci pneumonitis (PCP). The neuropathogenesis of this disorder appears to involve a cascade of viral products, various cytokines and chemokines, and neurotransmitters which promote ongoing inflammation, excitation, and overstimualtion of the N-methyl-D-aspartate type receptor (NMDAR) system. These subsequently lead to neuronal injury and death secondary to apoptosis or necrosis, astrocytosis, as well as dentritic and synaptic damage. The frequency of the most severe forms of encephalopathy among children has dropped dramatically since the introduction of highly active antiretroviral therapy (HAART). Of concern, however, is the possibility that a more insidious form of this disorder may be occurring presently among older vertically infected children as a result of inadequate penetration of HAART agents into the cerebrospinal fluid (CSF). This paper will review what published data there is as yet that bears on this question.

The AIDS dementia complex: clinical and basic neuroscience with implications for novel molecular therapies

The AIDS dementia complex (ADC, also referred to as HIV-associated cognitive impairment) is a common disorder among HIV-infected patients associated with both inflammatory and neurodegenerative processes. This review describes recent advances in the clinical and basic neurosciences of HIV infection and discusses the multivariable nature of what has become a chronic disorder in the context of highly active antiretroviral therapies (HAART). Since its initial description twenty years ago, advances in cell and molecular biology along with those in neuroimaging have furthered our understanding of the underlying pathogenic mechanisms. The clinical and neuropsychological profile of ADC is generally consistent with a "frontal-subcortical" pattern of injury. Neuropathogenesis is largely driven by indirect mechanisms mediated by infected, or more commonly, immune activated macrophages, which secrete viral and host-derived factors. Magnetic resonance spectroscopy (MRS) provides a robust in vivo method to measure the inflammatory and neurotoxic events triggered by these factors and their associated signals. Although the use of combined or highly active antiretroviral therapies (HAART) has significantly improved survival rates, cerebral injury and cognitive impairment remain common events. Factors such as aging and chronic infection will likely impact the course of this disease, its pathogenesis, and treatment. The combined observations presented in this review suggest a number of critical areas for future inquiry.

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.

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.

CNS activity of Pokeweed anti-viral protein (PAP) in mice infected with lymphocytic choriomeningitis virus (LCMV)

Background

Others and we have previously described the potent in vivo and in vitro activity of the broad-spectrum antiviral agent PAP (Pokeweed antiviral protein) against a wide range of viruses. The purpose of the present study was to further elucidate the anti-viral spectrum of PAP by examining its effects on the survival of mice challenged with lymphocytic choriomeningitis virus (LCMV).

Methods

We examined the therapeutic effect of PAP in CBA mice inoculated with intracerebral injections of the WE54 strain of LCMV at a 1000 PFU dose level that is lethal to 100% of mice within 7–9 days. Mice were treated either with vehicle or PAP administered intraperitoneally 24 hours prior to, 1 hour prior to and 24 hours, 48 hours 72 hours and 96 hours after virus inoculation.

Results

PAP exhibits significant in vivo anti- LCMV activity in mice challenged intracerebrally with an otherwise invariably fatal dose of LCMV. At non-toxic dose levels, PAP significantly prolonged survival in the absence of the majority of disease-associated symptoms. The median survival time of PAP-treated mice was >21 days as opposed to 7 days median survival for the control (p = 0.0069).

Conclusion

Our results presented herein provide unprecedented experimental evidence that PAP exhibits antiviral activity in the CNS of LCMV-infected mice.

Sequence heterogeneity and viral dynamics in cerebrospinal fluid and plasma during antiretroviral therapy

Understanding of human immunodeficiency virus (HIV) neuropathogenesis has been greatly enhanced by careful analyses of postmortem brain tissue, as well as by primate models of infection with related lentiviruses. However, brain tissue from persons living with HIV infection is rarely available for study, and elegant observations from primate systems may require confirmation in humans. Because of these inherent limitations, it is important to learn as much as possible by studying cerebrospinal fluid (CSF) during HIV infection. The present discussion considers selected issues relevant to the study of CSF from HIV-infected individuals. These include a strategy to intensely sample CSF to better understand viral dynamics and the role of the brain as a pharmacologic sanctuary site, evidence for HIV sequence diversity in CSF and plasma during HIV therapy and the implications of such diversity, and the importance of host genetics relevant to studying HIV neuropathogenesis.

Long-term virological effect of highly active antiretroviral therapy on cerebrospinal fluid and relationship with genotypic resistance

The objective of this study was to assess the long-term virological response in cerebrospinal fluid (CSF) in patients treated with highly active antiretroviral therapy (HAART) and to compare this response to CSF and plasma human immunodeficiency virus (HIV) drug resistance profiles. Paired CSF and plasma specimens were drawn from 18 patients receiving HAART at baseline and after 9 to 70 months of therapy. At baseline, median HIV-1 RNA concentrations were 4.13 log10 copies/ml in CSF and 5.31 log10 copies/ml in plasma. At the time of on-therapy CSF sampling, HIV-1 RNA was undetectable in CSF from 13/18 patients (72%), and in plasma from 9/18 patients (50%). The genotypic analysis at baseline revealed reverse transcriptase (RT) resistance mutations in 7 of 11 (64%) CSF samples and in 8 of 11 (73%) plasma samples. No patient had protease resistance mutations, except for secondary mutations. At the time of virological failure in CSF, new RT and protease resistance mutations were found in both CSF and plasma of the two patients with both baseline and on-treatment paired evaluations. At long-term follow-up, the proportion of patients failing to respond virologically was lower in CSF than in plasma. Virological failure in CSF was associated with failure to respond in plasma and onset of new drug resistance mutations in both compartments.

Two phases of HIV RNA decay in CSF during initial days of multidrug therapy

BACKGROUND

Defining cellular and tissue sources of HIV-1 in CSF is important for understanding disease pathogenesis and optimal therapies for HIV infection in the brain.

OBJECTIVE

To identify the time of maximal viral decay in CSF during the initial days of antiretroviral therapy.

METHODS

Serial CSF and plasma data were available from four adults who underwent ultraintensive CSF sampling for 48 hours at baseline and again beginning 72 hours after starting antiretroviral therapy. Regression lines were generated using HIV-1 RNA data from 17 on-treatment serial CSF samples obtained at 3-hour intervals. Viral RNA was quantified by Nuclisens and Amplicor HIV-1 Monitor assays.

RESULTS

Extrapolation of regression lines intersected baseline below actual baseline CSF HIV-1 RNA concentrations, indicating that virus decayed most rapidly on days 1 through 3 with half-lives of no more than 0.9 to 2.8 days. Half-lives on days 4 and 5 ranged from 1.3 to 4.9 days. Plasma data also showed early rapid decay.

CONCLUSIONS

Multiple phases of viral decay suggest that virus in CSF originates from at least two sources during untreated, asymptomatic HIV-1 infection. The short half-life indicates that the primary source is CD4+ T cells. Sampling during days 1 through 3 and different stages of disease will better define sources of virus.

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.

Stampidine prevents mortality in an experimental mouse model of viral hemorrhagic fever caused by lassa virus

BACKGROUND

The potential use of microorganisms as agents of biological warfare (BW) is a growing concern. Lassa virus, a member of the Arenavirus class of Hemorrhagic fever (HF) viruses has emerged as a worldwide concern among public health officials. The purpose of the present study was to further elucidate the antiviral activity spectrum of stampidine, a novel nucleoside analog with potent anti-viral activity against the immunodeficiency viruses HIV-1, HIV-2, and FIV, by examining its effects on survival of mice challenged with Lassa virus.

METHODS

We examined the therapeutic effect of Stampidine in CBA mice inoculated with intracerebral injections of the Josiah strain of Lassa virus. Mice were treated either with vehicle or nontoxic doses of stampidine administered intraperitoneally 24 hours prior to, 1 hour prior to, and 24 hours, 48 hours, 72 hours, and 96 hours after virus inoculation.

RESULTS

The probability of survival following the Lassa challenge was significantly improved for stampidine treated mice (Kaplan Meier, Chi-squared = 11.7, df = 2, Log-Rank p-value = 0.003).

CONCLUSION

Therefore, stampidine shows clinical potential as a new agent for treatment of viral hemorrhagic fevers caused by Lassa virus.

Hydroxyurea transport across the blood-brain and blood-cerebrospinal fluid barriers of the guinea-pig

Hydroxyurea is used in the treatment of HIV infection in combination with nucleoside analogues, 2'3'-didehydro-3'deoxythymidine (D4T), 2'3'-dideoxyinosine or abacavir. It is distributed into human CSF and is transported from the CSF to sub-ependymal brain sites, but its movement into the brain directly from the blood has not been studied. This study addressed this by a brain perfusion technique in anaesthetized guinea-pigs. The carotid arteries were perfused with an artificial plasma containing [14C]hydroxyurea (1.6 microm) and a vascular marker, [3H]mannitol (4.6 nm). Brain uptake of [14C]hydroxyurea (8.0 +/- 0.9%) was greater than [3H]mannitol (2.4 +/- 0.2%; 20-min perfusion, n = 8). CSF uptake of [14C]hydroxyurea (5.6 +/- 1.5%) was also greater than [3H]mannitol (0.9 +/- 0.3%; n = 4). Brain uptake of [14C]hydroxyurea was increased by 200 microm hydroxyurea, 90 microm D4T, 350 microm probenecid, 25 microm digoxin, but not by 120 microm hydroxyurea, 16.5-50 microm D4T, 90 microm 2'3'-dideoxyinosine or 90 microm abacavir. [14C]Hydroxyurea distribution to the CSF, choroid plexus and pituitary gland remained unaffected by all these drugs. The metabolic half-life of hydroxyurea was > 15 h in brain and plasma. Results indicate that intact hydroxyurea can cross the brain barriers, but is removed from the brain by probenecid- and digoxin-sensitive transport mechanisms at the blood-brain barrier, which are also affected by D4T. These sensitivities implicate an organic anion transporter (probably organic anion transporting polypeptide 2) and possibly p-glycoprotein in the brain distribution of hydroxyurea and D4T.

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.