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

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

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

HIV Encephalopathy in ART-Naïve, Hospitalized Infants in Mozambique

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Recovery of HIV encephalopathy in perinatally infected children on antiretroviral therapy

AIM

To describe the trajectory of clinical signs in children who developed human immunodeficiency virus encephalopathy (HIVE) after starting early antiretroviral therapy (ART).

METHOD

This was a retrospective case-cohort description of HIVE among Cape Town participants from the Children with HIV Early AntiRetroviral treatment (CHER) trial. Criteria for HIVE diagnosis were at least two of: (1) acquired central motor deficit, (2) impaired brain growth, and (3) failure to attain or loss of developmental milestones in the absence of an alternative aetiology.

RESULTS

Of 133 surviving participants who initiated ART at a median age of 9 weeks and who were followed until a median age of 6 years, 20 (12%) developed HIVE at a median age 31 months (interquartile range 19-37). In these, the first neurological deterioration was noticed at a median age of 19 months, when 16 were on ART and nine had undetectable HIV viral load for a median of 12 months. Signs of upper motor neurons were present in 18, of whom 12 resolved and four had persistent spastic diplegia; 19 had motor delay, of whom 14 resolved; 12 had language delay, of whom 11 resolved; and 16 had impaired brain growth, of whom only five recovered. For the 16 participants already on ART at HIVE diagnosis, regimens were not altered in response to diagnosis.

INTERPRETATION

HIVE may occur despite early ART initiation and virological suppression and then resolve on unchanged ART, most likely as intrathecal inflammation subsides.

WHAT THIS PAPER ADDS

Despite suppressive antiretroviral therapy, children can develop human immunodeficiency virus encephalopathy, The most common manifestations are motor deficits and impaired brain growth. Most experience improvement, with many resolving without additional intervention.

NeuroAIDS in children

The human immunodeficiency virus-1 (HIV-1) enters the central nervous system compartment within the first few weeks of systemic HIV infection and may cause a spectrum of neurologic complications. Without combination antiretroviral therapy (cART), 50-90% of all HIV-infected infants and children develop some form of neuroAIDS. Of the estimated 2.3 million children less than 15 years of age who were living in sub-Saharan Africa at the end of 2014, only 30% were receiving cART, suggesting that there is a large burden of neuroAIDS among HIV-infected children in sub-Saharan Africa. There is complex interplay between the disease process itself, the child's immune reaction to the disease, the secondary complications, the side-effects of antiretroviral drugs, and inadequate antiretroviral drug uptake into the central nervous system. In addition there is the layering effect from the multiple socioeconomic challenges for children living in low- and middle-income countries. Adolescents may manifest with a range of neurocognitive sequelae from mild neurocognitive disorder through to severe neurocognitive impairment. Neuroimaging studies on white-matter tracts have identified dysfunction, especially in the frontostriatal networks needed for executive function. Psychiatric symptoms of depression, attention deficit hyperactivity disorder, and behavioral problems are also commonly reported in this age group. Antiretroviral drugs may cause treatment-limiting neurologic and neuropsychiatric adverse reactions. The following chapter addresses the neurologic complications known to be, and suspected of being, associated with HIV infection in children and adolescents.

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.

Young adults perinatally infected with HIV perform more poorly on measures of executive functioning and motor speed than ethnically matched healthy controls

Perinatal HIV is associated with significant neurocognitive morbidities, but few studies have examined cognitive impact of early HIV infection on patients surviving to adulthood. The purpose of this study was to evaluate neurocognitive outcomes among a cohort of perinatally infected young adults. Individuals between the ages of 18 and 24 with perinatal infection were recruited for this cross-sectional study along with similarly aged healthy controls. Participants completed an MRI and brief neuropsychological assessment battery. Multivariate analysis of covariance controlling for age, gender, race/ethnicity, and education was completed to detect differences between the HIV+ and control groups. Multivariable linear regression was performed to assess HIV-associated factors potentially impacting neuropsychological findings among the HIV+ group. Twenty-nine HIV+ young adults and 13 healthy controls were included in the study. After adjusting for age and sociodemographic variables, the HIV+ group scored lower on attention/working memory (Digit Span (p = .008) and Letter-Number Sequencing (p = .038)), set-shifting (DKEFS Trail Making Test Condition 4 (p = .026) and motor speed (DKEFS Trail Making Test Condition 5 (p = .003)). For the HIV+ group, nadir CD4 was associated with better Letter-Number Sequencing score (p = .029) and use of highly active antiretroviral therapy was associated with better performance on Category Fluency (p = .040). After controlling for sociodemographic variables, executive dysfunction persists among young adults with perinatal HIV infection in comparison to controls. Future studies to further elucidate the impact of executive dysfunction on independent living and functional outcomes are indicated.

Immunoinflammatory diseases of the central nervous system - the tale of two cytokines

Cytokines are potent mediators of cellular communication that have crucial roles in the regulation of innate and adaptive immunoinflammatory responses. Clear evidence has emerged in recent years that the dysregulated production of cytokines may in itself be causative in the pathogenesis of certain immunoinflammatory disorders. Here we review current evidence for the involvement of two different cytokines, IFN-α and IL-6, as principal mediators of specific immunoinflammatory disorders of the CNS. IFN-α belongs to the type I IFN family and is causally linked to the development of inflammatory encephalopathy exemplified by the genetic disorder, Aicardi-Goutières syndrome. IL-6 belongs to the gp130 family of cytokines and is causally linked to a number of immunoinflammatory disorders of the CNS including neuromyelitis optica, idiopathic transverse myelitis and genetically linked autoinflammatory neurological disease. In addition to clinical evidence, experimental studies, particularly in genetically engineered mouse models with astrocyte-targeted, CNS-restricted production of IFN-α or IL-6 replicate many of the cardinal neuropathological features of these human cytokine-linked immunoinflammatory neurological disorders giving crucial evidence for a direct causative role of these cytokines and providing further rationale for the therapeutic targeting of these cytokines in neurological diseases where indicated.

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.

Type I interferon in neurological disease-the devil from within

The members of the type I interferon (IFN-I) family of cytokines are pleiotropic factors that have seminal roles in host defence, acting as antimicrobial and antitumor mediators as well as potent immunomodulatory factors that bridge the innate and adaptive immune responses. Despite these beneficial actions there is mounting evidence that link inappropriate or chronic production of IFN-I in the CNS to the development of a number of severe neuroinflammatory disorders. The most persuasive example is the genetically determined inflammatory encephalopathy, Aicardi-Goutières syndrome (AGS) in which patients have chronically elevated IFN-α production in the CNS. The presentation of AGS can often mimic congenital viral infection, however, molecular genetic studies have identified mutations in six genes that can cause AGS, most likely via dysregulated nucleic acid metabolism and activation of the innate immune response leading to increased intrathecal production of IFN-α. The role of IFN-α as a pathogenic factor in AGS and other neurological disorders has gained considerable support from experimental studies. In particular, a transgenic mouse model with CNS-restricted production of IFN-α replicates many of the cardinal neuropathologic features of AGS and reveal IFN-I to be the "devil from within", mediating molecular and cellular damage within the CNS. Thus, targeting IFN-I may be an effective strategy for the treatment of AGS as well as some other autoimmune and infectious neurological "interferonopathies".

[Characteristics of human immunodeficiency virus-1 infected children receiving highly active antiretroviral therapy: a cross-sectional study]

INTRODUCTION

Since 1996, when HAART became available, there has been a change in the course of HIV-infection, leading it to become a chronic disease. Our aim was to describe the characteristics of the children followed up in our hospital.

PATIENTS AND METHODS

A cross-sectional study was conducted on 32 HIV-infected children followed up until December-2010, at the University-Hospital de Getafe. Clinical and laboratory information from the last visit was collected for the evaluation of patients.

RESULTS

Thirty-two children with HIV-1 were evaluated, 29 infected through vertical-transmission. The median age was 14 years. According to the CDC classification, 56% (18/32) of children were in category A, 28% (9/32) B and 16% (5/32) C. Immunological class was 3 in 75% of children, class 2 in 9% and class 1 in 16%. The median nadir of CD4 was 337 cells/ml (12%). The median current CD4 was 749 (31%). Only one adolescent had a CD4% below 200 cells/ml due to lack of adherence. Twenty-eight patients (87%) were receiving HAART, and 4 patients were off antiretroviral treatment. Among the patients treated, 26 (93%) had viral loads <200 copies/ml. The median viral-load was<20 copies/ml. Median time on antiretroviral treatment was 10 years. The combination more frequently used was two nucleoside reverse transcriptase inhibitors (NRTI) and one protease inhibitor (PI), that was given to 15 patients (47%), followed by 2 NRTI, and one non-nucleoside reverse transcriptase inhibitor (NNRTI) in 8 patients (29%). Two children received rescue therapy including raltegravir, one with tipranavir and the other with darunavir. A total of 12 patients (43%) received medication once a day, 7 of them with fixed-dose combinations in a single tablet (25%). There were metabolic complications, including hyperlipidaemia or lipodystrophy were observed in 17 children (53%).

CONCLUSIONS

Most of our patients are receiving HAART, with good virological and immunological control. The prevalence of metabolic abnormalities was high. Strategies to improve adherence and decrease toxicities are needed in perinatally-acquired HIV-infected children.

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

OBJECTIVE

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSION

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

Delirium in children with HIV/AIDS

Delirium in children has received little attention from researchers until very recently, despite being a frequently encountered clinical problem, particularly in the context of human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). In this article, we report 3 cases of severe hyperactive delirium occurring in children with advanced HIV/AIDS in the context of probable underlying HIV encephalopathy and complex drug-drug interactions. We also present a hypothesis in relation to HIV-associated delirium as a potential neuropsychiatric manifestation of the immune reconstitution inflammatory syndrome in children commenced on highly active antiretroviral therapy.

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.

Promoting child and adolescent mental health in the context of the HIV/AIDS pandemic with a focus on sub-Saharan Africa

BACKGROUND

The pandemic of HIV/AIDS is actually a composite of many regional and national-level epidemics. The progress made in many parts of the developed and developing world is tempered by the continued devastating consequences of HIV infection in sub-Saharan Africa (SSA). This review focuses on the ways in which children and adolescents are impacted by the epidemic, giving particular attention to their mental health.

METHODS

A health promotion framework is adopted to guide analysis. Three issues are covered: prevention of HIV infection, care and treatment of children infected with HIV, and care of children whose caregivers are ill or have died of AIDS. Existing reviews and literature search engines were used to review the scientific literature, focusing on the past five years.

RESULTS

Preventive interventions continue to manifest limited benefits in behavioral changes. More complex causal models and improved behavioral measures are needed. In the African context, the time has come to view pediatric AIDS as a chronic disease in which the mental health of caregivers and children influences important aspects of disease prevention and management. Increasingly sophisticated studies support earlier findings that social and psychological functioning, educational achievement and economic well-being of children who lose parents to AIDS are worse than that of other children.

CONCLUSIONS

Important changes are taking place in SSA in increased access to HIV testing and antiretroviral therapies. To be effective in promoting mental health of children and adolescents, interventions require a more fundamental understanding of how to build HIV competence at personal and community levels. A key recommendation calls for the design and execution of population-based studies that include both multilevel and longitudinal features. Such rigorous conceptual and empirical investigations that assess the capacities of children are required to mobilize children, families and communities in comprehensive actions plans for prevention, treatment and care in response to the enduring HIV/AIDS pandemic.

Neurodevelopment and chronic illness: Mechanisms of disease and treatment

Successful treatment of many childhood diseases once considered terminal has resulted in the emergence of long-term effects of the disease or consequences of treatment that were previously unrecognized. Many of these long-term effects involve the central nervous system (CNS) and are developmental in the way that they emerge over time. Because we are now able to observe the natural history of childhood diseases such as sickle cell anemia or HIV, or the consequences of treatment of disease such as leukemia, brain tumors, or kidney disease, we are also able to study a number of biological mechanisms that result in long-term neurocognitive impairment. While some of the neurodevelopmental outcomes can be directly linked to structural damage of the CNS, other systems (e.g., hematologic, immunologic, pulmonary) appear to play crucial indirect roles in the development of the CNS and neurocognitive abilities because of the way that they affect the course of brain development and activity of the brain across time. Important interactions between acute disease factors, biological mechanisms, age at the time of disease or treatment effect, and disruptions in patterns of development after successful treatment or management all provide support for a neurodevelopmental model of childhood chronic illness. Testing this model may make it possible to more accurately predict the timing and degree of severity of long-term neurodevelopmental consequences, provide guidance for improved treatment and prevention, and offer better understanding of neurodevelopmental disruptions that occur in other non-chronic illness related disabilities.