Changing clinical phenotypes of HIV-associated neurocognitive disorders

Expression of HIV envelope protein in the human central nervous system

OBJECTIVE/DESIGN

The HIV envelope glycoprotein gp120 contributes to neuronal damage that could lead to HIV-mediated neurocognitive disorder. However, it is debated whether gp120 could promote direct neurotoxicity to synapses as it may not be present in the central nervous system of people with HIV (PWH) on antiretroviral therapy (ART). This study sought to establish whether gp120 is expressed in the human central nervous system in the pre-ART and post-ART era.

METHODS

We utilized real-time PCR to detect the envelope mRNA in postmortem caudate nucleus from pre-ART era. HIV-negative samples were used as controls. We then used RNAscope fluorescence multiplex to identify which cells express the envelope mRNA. To determine whether gp120 is present despite ART, we analyzed cerebrospinal fluid (CSF) samples from PWH on ART using mass spectrometry.

RESULTS

Using PCR, we detected the envelope mRNA in the caudate nucleus from PWH with neurocognitive impairment but not in control samples. With RNAscope, we detected the envelope mRNA in microglia and astrocytes in the frontal cortex and caudate nucleus from HIV-positive tissue. With mass spectrometry, we identified a gp120 peptide in the CSF of PWH on antiretroviral therapy ( n  = 20) but not in control participants ( n  = 7).

CONCLUSION

Our data suggest that despite antiretroviral therapy, gp120 is expressed and likely released by infected cells, suggesting that gp120 could be one of the key factors in the neuropathology observed in PWH.

Serotonergic and Dopaminergic Function in Neuropsychiatrically Asymptomatic People With HIV on Antiretroviral Therapy

OBJECTIVE

People with HIV (PWH) on antiretroviral therapy (ART) still experience neurocognitive dysfunction and accelerated brain volume loss. To assess whether the serotonergic and dopaminergic systems are affected, we used [11C]DASB positron emission tomography (PET) to assess presynaptic serotonergic function and [18F]FDOPA PET to measure presynaptic dopaminergic reserve in neurocognitively and psychiatrically asymptomatic PWH on ART, compared to seronegative controls (SCs).

METHODS

We compared [11C]DASB binding (BPND) (n = 17 PWH/19 SCs) and [18F]FDOPA influx constant (Ki) (n = 20 PWH/19 SCs) of PWH and SCs. We assessed correlations of Ki and BPND with CSF cytokines and imaging/clinical/neuropsychological outcomes using multivariable and univariable models.

RESULTS

BPND, Ki, and neurocognitive and psychiatric scores did not differ between PWH and SCs. Higher BPND correlated with better neurocognitive scores in the whole group. Ki did not correlate with neurocognitive scores. Neither BPND nor Ki correlated with depression scores. Caudate and putamen MRI volumes trended smaller in PWH. While CSF inflammatory cytokines were higher in PWH, they did not correlate with either PET measure.

INTERPRETATIONS

Presynaptic serotonin transporter density (measured by [11C]DASB) is a good correlate of the neurocognitive function in PWH and SCs. Despite long-term ART, PWH still showed trends for basal ganglia volume loss, consistent with known disproportionate global and regional volume loss in PWH compared to SCs. Aspects of serotonergic and dopaminergic function, namely, presynaptic SERT density and dopaminergic reserve, however, are not different in this PWH cohort on ART from SCs, despite persistent neuroinflammation and trends of volume loss. This could reflect a functional compensatory process versus minimal, below-detection-level dysfunction.

Cannabinoid Receptor 2 (CB2R) as potential target for the pharmacological treatment of neurodegenerative diseases

The endocannabinoid system (ECS) is a ubiquitous physiological system that plays a crucial role in maintaining CNS homeostasis and regulating its functions. It includes cannabinoid receptors (CBRs), endogenous cannabinoids (eCBs), and the enzymes responsible for their synthesis and degradation. In recent years, growing evidence has highlighted the therapeutic potential of the ECS and CBRs, in a wide range of severe diseases and pathological conditions, including Alzheimer's and Parkinson's diseases, Amyotrophic Lateral Sclerosis, Multiple Sclerosis, Huntington's Disease, HIV-1 associated neurocognitive disorders, neuropathic pain and migraine. Targeting the cannabinoid type 2 receptor (CB2R) has gained attention due to its ability to (i) mitigate neuroinflammatory responses, (ii) regulate mitochondrial function and (iii) provide trophic support, all without eliciting the psychotropic actions associated with CB1R activation. This review aims to explore the potential of CB2R modulation as a strategy for the prevention and treatment of neurologic disorders, exploring both preclinical and clinical findings.

Health literacy mediates the association between cognition and healthcare provider interactions among gay and bisexual men with HIV disease

Introduction: Gay and bisexual men (GBM) account for the highest rates of incident infection with HIV in the U.S., and experience social, systemic barriers to accessing and engaging in healthcare services. Interacting with healthcare providers can be a complex process for some GBM with HIV disease. The current study examined the contributions of cognition and health literacy to perceived interactions with healthcare providers among GBM with HIV disease. Methods: The sample included 100 adults with HIV disease (ages 24-75) who identified as GBM. All participants completed the Dealing with Health Professionals subscale of the Beliefs Related to Medication Adherence survey, as well as the Cogstate neuropsychological battery, self-report measures of cognitive symptoms, and well-validated measures of health literacy. Results: Worse performance-based cognition and subjective cognitive symptoms were both associated with perceived difficulties dealing with healthcare providers, but these associations were fully mediated by lower health literacy. Conclusion: Health literacy may play a role in the association between poorer cognitive functioning and difficulties navigating healthcare interactions among GBM with HIV disease. Further studies are needed to determine whether cognitive approaches to enhancing the access, understanding, and use of health information in GBM with HIV disease improves healthcare interactions and outcomes.

Viruses and the Brain-A Relationship Prone to Trouble

Neurological disorders, some of which are associated with viral infections, are growing due to the aging and expanding population. Despite strong defenses of the central nervous system, some viruses have evolved ways to breach them, which often result in dire consequences. In this review, we recount the various ways by which different viruses can enter the CNS, and we describe the consequences of such invasions. Consequences may manifest as acute disease, such as encephalitis, meningitis, or result in long-term effects, such as neuromuscular dysfunction, as occurs in poliomyelitis. We discuss evidence for viral involvement in the causation of well-known chronic neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, as well as vascular dementia in the elderly. We also describe the approaches currently available to control a few of the neural viral infections. These include antivirals that are effective against human immunodeficiency virus and herpes simplex virus, as well as vaccines valuable for controlling rabies virus, poliomyelitis virus, and some flavivirus infections. There is an urgent need to better understand, at a molecular level, how viruses contribute to acute and, especially, chronic neurological diseases and to develop more precise and effective vaccines and therapies.

α-Synuclein fibrils enhance HIV-1 infection of human T cells, macrophages and microglia

HIV-associated neurocognitive disorders (HAND) and viral reservoirs in the brain remain a significant challenge. Despite their importance, the mechanisms allowing HIV-1 entry and replication in the central nervous system (CNS) are poorly understood. Here, we show that α-synuclein and (to a lesser extent) Aβ fibrils associated with neurological diseases enhance HIV-1 entry and replication in human T cells, macrophages, and microglia. Additionally, an HIV-1 Env-derived amyloidogenic peptide accelerated amyloid formation by α-synuclein and Aβ peptides. Mechanistic studies show that α-synuclein and Aβ fibrils interact with HIV-1 particles and promote virion attachment and fusion with target cells. Despite an overall negative surface charge, these fibrils facilitate interactions between viral and cellular membranes. The enhancing effects of human brain extracts on HIV-1 infection correlated with their binding to Thioflavin T, a dye commonly used to stain amyloids. Our results suggest a detrimental interplay between HIV-1 and brain amyloids that may contribute to the development of neurodegenerative diseases.

The impact of aging on HIV-1-related neurocognitive impairment

Depending on the population studied, HIV-1-related neurocognitive impairment is estimated to impact up to half the population of people living with HIV (PLWH) despite the availability of combination antiretroviral therapy (cART). Various factors contribute to this neurocognitive impairment, which complicates our understanding of the molecular mechanisms involved. Biological aging has been implicated as one factor possibly impacting the development and progression of HIV-1-related neurocognitive impairment. This is increasingly important as the life expectancy of PLWH with virologic suppression on cART is currently projected to be similar to that of individuals not living with HIV. Based on our increasing understanding of the biological aging process on a cellular level, we aim to dissect possible interactions of aging- and HIV-1 infection-induced effects and their role in neurocognitive decline. Thus, we begin by providing a brief overview of the clinical aspects of HIV-1-related neurocognitive impairment and review the accumulating evidence implicating aging in its development (Part I). We then discuss potential interactions between aging-associated pathways and HIV-1-induced effects at the molecular level (Part II).

Non-pharmaceutical interventions for people living with HIV with cognitive impairment: A scoping review

BACKGROUND

Cognitive impairment (CI) in HIV is often of multifactorial causation, and remains a prominent issue in the age of effective combination antiretroviral therapy (cART), affecting approximately 14% of people living with HIV. Despite the 2018 BHIVA directive stating the importance of commencing rehabilitation strategies in people living with HIV with CI, no types of cognitive rehabilitations or other non-pharmaceutical interventions are specifically recommended. This scoping review aimed to describe the types of and evidence relating to the non-pharmaceutical interventions which have been examined in people living with HIV with CI.

METHODS

Studies were identified from five electronic databases. Criteria for study inclusion were studies describing a non-pharmaceutical intervention published after 1st January 2000 in English, in a population of adults living with HIV with CI detected at baseline, without significant psychiatric or substance-misuse co-morbidity.

RESULTS

Fourteen studies met the criteria for inclusion, with the Frascati criteria most commonly used to define CI within participant populations. The median intervention length was 12 weeks (IQR = 6.5). Nine studies investigated interventions with some component of computerised cognitive training (CCT); other interventions included diet, exercise and goal management training. Studies most commonly examined neurocognitive outcomes, but also considered other outcomes including quality of life, depressive symptomatology, intervention acceptability and cART adherence. Eight studies observed improvement in cognition with CCT, with effects often maintained for several weeks post-intervention, however, results were not always statistically significant. Self-reported cognitive improvement and intervention acceptability was high amongst participants completing CCT.

CONCLUSIONS

There was heterogeneity across studies not only in intervention type, but in diagnostic tools used, the chosen outcome measures and cognitive batteries, making comparison difficult. Findings, however, indicate that CCT interventions may produce benefits in cognition and are acceptable to patients. Further research is required in larger samples, alongside identifying specific intervention components that improve outcomes.

Neuropsychological tests associated with symptomatic HIV-associated neurocognitive disorder (HAND) in a cohort of older adults in Tanzania

OBJECTIVE

Human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) prevalence is expected to increase in East Africa as treatment coverage increases, survival improves, and this population ages. This study aimed to better understand the current cognitive phenotype of this newly emergent population of older combination antiretroviral therapy (cART)-treated people living with HIV (PLWH), in which current screening measures lack accuracy. This will facilitate the refinement of HAND cognitive screening tools for this setting.

METHOD

This is a secondary analysis of 253 PLWH aged ≥50 years receiving standard government HIV clinic follow-up in Kilimanjaro, Tanzania. They were evaluated with a detailed locally normed low-literacy neuropsychological battery annually on three occasions and a consensus panel diagnosis of HAND by Frascati criteria based on clinical evaluation and collateral history.

RESULTS

Tests of verbal learning and memory, categorical verbal fluency, visual memory, and visuoconstruction had an area under the receiver operating characteristic curve >0.7 for symptomatic HAND (s-HAND) (0.70-0.72; p < 0.001 for all tests). Tests of visual memory, verbal learning with delayed recall and recognition memory, psychomotor speed, language comprehension, and categorical verbal fluency were independently associated with s-HAND in a logistic mixed effects model (p < 0.01 for all). Neuropsychological impairments varied by educational background.

CONCLUSIONS

A broad range of cognitive domains are affected in older, well-controlled, East African PLWH, including those not captured in widely used screening measures. It is possible that educational background affects the observed cognitive impairments in this setting. Future screening measures for similar populations should consider assessment of visual memory, verbal learning, language comprehension, and executive and motor function.

Biopsychosocial phenotypes in people with HIV in the CHARTER cohort

Neuropsychiatric complications such as neurocognitive impairment and depression are common in people with HIV despite viral suppression on antiretroviral therapy, but these conditions are heterogeneous in their clinical presentations and associated disability. Identifying novel biopsychosocial phenotypes that account for neurocognitive performance and depressive and functional symptoms will better reflect the complexities encountered in clinical practice and may have pathological and therapeutic implications. We classified 1580 people with HIV based on 17 features, including 7 cognitive domains, 4 subscales of the Beck depression inventory-II, 5 components of the patient's assessment of own functioning inventory, and dependence in instrumental and basic activities of daily living. A two-stage clustering procedure consisting of dimension reduction with self-organizing maps and Mahalanobis distance-based k-means clustering algorithms was applied to cross-sectional data. Baseline demographic and clinical characteristics were compared between the phenotypes, and their prediction on the biopsychosocial phenotypes was evaluated using multinomial logistic regression. Four distinct phenotypes were identified. Participants in Phenotype 1 overall did well in all domains. Phenotype 2 had mild-to-moderate depressive symptoms and the most substance use disorders. Phenotype 3 had mild-to-moderate cognitive impairment, moderate depressive symptoms, and the worst daily functioning; they also had the highest proportion of females and non-HIV conditions that could affect cognition. Phenotype 4 had mild-to-moderate cognitive impairment but with relatively good mood, and daily functioning. Multivariable analysis showed that demographic characteristics, medical conditions, lifetime cocaine use disorder, triglycerides, and non-antiretroviral therapy medications were important variables associated with biopsychosocial phenotype. We found complex, multidimensional biopsychosocial profiles in people with HIV that were associated with different risk patterns. Future longitudinal work should determine the stability of these phenotypes, assess factors that influence transitions from one phenotype to another, and characterize their biological associations.

Association between tight junction proteins and cognitive performance in untreated persons with HIV

BACKGROUND

HIV-associated neurocognitive disorders (HAND) still affects persons with HIV (PWH) and their pathogenesis is not completely understood. We aimed to explore the association between plasma and cerebrospinal fluid (CSF) markers of blood-brain barrier (BBB) impairment and HAND in untreated PWH.

DESIGN

Cross-sectional study.

METHODS

We enrolled untreated PWH, who underwent blood examinations and lumbar puncture to measure inflammation (IL-15, TNF-α), BBB damage (zonulin and tight junction proteins, tight junction proteins: occludin, claudin-5) and endothelial adhesion molecules (VCAM-1, ICAM-1). A comprehensive neurocognitive battery was used to diagnose HAND (Frascati criteria).

RESULTS

Twenty-one patients (21/78, 26.9%) patients presented HAND (100% ANI). HAND patients displayed more frequently non-CNS AIDS-defining conditions, lower nadir CD4 + T cells and increased CD4 + T-cell exhaustion (lower CD4 + CD127 + and CD4 + CD45RA + T-cell percentages), in comparison to individuals without cognitive impairment. Furthermore, HAND was characterized by higher plasma inflammation (IL-15) but lower CSF levels of biomarkers of BBB impairment (zonulin and occludin). The association between BBB damage with HAND was confirmed by fitting a multivariable logistic regression. CSF/plasma endothelial adhesion molecules were not associated with HAND but with a poor performance in different cognitive domains.

CONCLUSION

By showing heightened inflammation and BBB impairment, our study suggests loss of BBB integrity as a possible factor contributing to the development of HAND in untreated PWH.

Neurocognitive profile in HIV subjects on INSTI-regimen- one year follow up: Is there room for optimism?

The introduction of antiretroviral therapy (ART) has successfully changed the clinical course of people with HIV, leading to a significant decline in the incidence of HIV-related neurocognitive disorders. Integrase strand transferase inhibitors (INSTI) are recommended and preferred first-line ART for the treatment of HIV-1 infection in ART-naïve subjects. This type of therapy regimen is expected to have higher CNS penetration, which may bring more cognitive stability or even make significant cognitive improvement in people with HIV. The study aimed to follow up on neurocognitive performance in HIV subjects on two types of INSTI therapy regimens at two-time points, one year apart. The study sample consisted of 61 ART naïve male participants, of which 32 were prescribed raltegravir (RAL) and 29 dolutegravir (DTG). There was no significant difference between subsamples according to the main sociodemographic (age, education level) and clinical characteristics (duration of therapy, nadir CD4 cells level, CD4 cells count, CD8 cells, CD4/CD8 ratio). For neurocognitive assessment, six measures were used: general cognitive ability (MoCA test), verbal fluency (total sum score for phonemic and category fluency), verbal working memory (digit span forward), cognitive capacity (digit span backwards), sustained attention (Color Trail Test 1), and divided attention (Color Trail Test 2). In both therapy groups (RAL and DTG), there was no significant decrease in neurocognitive achievement on all used measures over a one-year follow-up in both therapy groups. A statistically significant interactive effect of time and type of therapy was found on the measure of divided attention-DTG group showed slight improvement, whereas RAL group showed slight decrease in performance. During the one-year follow-up of persons on INSTI-based regimen, no significant changes in cognitive achievement were recorded, which suggests that the existing therapy can have a potentially positive effect on the maintenance of neurocognitive achievement.

Lack of Association of Vascular Risk Factors with HIV-Associated Neurocognitive Disorders in cART-Treated Adults Aged ≥ 50 Years in Tanzania

HIV-associated neurocognitive disorders (HAND) are highly prevalent in those ageing with HIV. High-income country data suggest that vascular risk factors (VRFs) may be stronger predictors of HAND than HIV-disease severity, but data from sub-Saharan Africa are lacking. We evaluated relationships of VRFs, vascular end-organ damage and HAND in individuals aged ≥ 50 in Tanzania. c-ART-treated individuals were assessed for HAND using consensus criteria. The prevalence of VRFs and end organ damage markers were measured. The independent associations of VRFs, end organ damage and HAND were examined using multivariable logistic regression. Data were available for 153 individuals (median age 56, 67.3% female). HAND was highly prevalent (66.7%, 25.5% symptomatic) despite well-managed HIV (70.5% virally suppressed). Vascular risk factors included hypertension (34%), obesity (10.5%), hypercholesterolemia (33.3%), diabetes (5.3%) and current smoking (4.6%). End organ damage prevalence ranged from 1.3% (prior myocardial infarction) to 12.5% (left ventricular hypertrophy). Measured VRFs and end organ damage were not independently associated with HAND. The only significant association was lower diastolic BP (p 0.030, OR 0.969 (0.943-0.997). Our results suggest that vascular risk factors are not major drivers of HAND in this setting. Further studies should explore alternative aetiologies such as chronic inflammation.

Sustained type I interferon signaling after human immunodeficiency virus type 1 infection of human iPSC derived microglia and cerebral organoids

Human immunodeficiency virus type-1 (HIV-1)-associated neurocognitive disorder (HAND) affects up to half of people living with HIV-1 and causes long term neurological consequences. The pathophysiology of HIV-1-induced glial and neuronal functional deficits in humans remains enigmatic. To bridge this gap, we established a model simulating HIV-1 infection in the central nervous system using human induced pluripotent stem cell (iPSC)-derived microglia combined with sliced neocortical organoids. Incubation of microglia with two replication-competent macrophage-tropic HIV-1 strains (JRFL and YU2) elicited productive infection and inflammatory activation. RNA sequencing revealed significant and sustained activation of type I interferon signaling pathways. Incorporating microglia into sliced neocortical organoids extended the effects of aberrant type I interferon signaling in a human neural context. Collectively, our results illuminate a role for persistent type I interferon signaling in HIV-1-infected microglia in a human neural model, suggesting its potential significance in the pathogenesis of HAND.

Cognitive impairment and neurocognitive profiles among people living with HIV and HIV-negative individuals older over 50 years: a comparison of IHDS, MMSE and MoCA

We aimed to examine the l differences in the assessment of neurocognitive impairment (NCI) using cognitive screening tools between PLWH and HIV-negative individuals and further compare the neurocognitive profiles between the two groups. This was baseline evaluation of Pudong HIV Aging Cohort, including 465 people living with HIV (PLWH) and 465 HIV-negative individuals aged over 50 years matched by age (± 3 years), sex and education. NCI was assessed using the Chinese version of Mini-mental State Examination (MMSE), the International HIV Dementia Scale (IHDS) and Beijing version of Montreal Cognitive Assessment (MoCA). In total, 258 (55.5%), 91 (19.6%), 273 (58.7%) of PLWH were classified as having NCI by the IHDS, MMSE and MoCA, compared to 90 (19.4%), 25 (5.4%), 135 (29.0%) of HIV-negative individuals, respectively (p < 0.05); such associations remained significant in multivariable analysis. PLWH showed a larger overlap of NCI detected by IHDS, MMSE, and MoCA. IHDS and MoCA detected almost all of the NCI detected by MMSE. IHDS-motor and psychomotor speeds and MoCA-executive function showed the greatest disparities between two groups. In multivariable analysis, older age and more depressive symptoms were positively associated with NCI regardless of the screening tools or HIV serostatus. PLWH over 50 years old display a higher prevalence of NCI and distinct neurocognitive profiles compared to HIV-negative individuals, despite viral suppression. Given the more considerable overlap in NCI classification in PLWH, it is advisable to choose one screening tool such as IHDS or MoCA to identify those potentially having NCI and then refer to more comprehensive neuropsychological assessment.

Early Initiation of Antiretroviral Therapy is Protective Against Seizures in Children With HIV in Zambia: A Prospective Case-Control Study

BACKGROUND

Seizures are relatively common among children with HIV in low- and middle-income countries and are associated with significant morbidity and mortality. Early treatment with antiretroviral therapy (ART) may reduce this risk by decreasing rates of central nervous system infections and HIV encephalopathy.

METHODS

We conducted a prospective, unmatched case-control study. We enrolled children with new-onset seizure from University Teaching Hospital in Lusaka, Zambia and 2 regional hospitals in rural Zambia. Controls were children with HIV and no history of seizures. Recruitment took place from 2016 to 2019. Early treatment was defined as initiation of ART before 12 months of age, at a CD4 percentage >15% in children aged 12-60 months or a CD4 count >350 cells/mm 3 for children aged 60 months or older. Logistic regression models were used to evaluate the association between potential risk factors and seizures.

RESULTS

We identified 73 children with new-onset seizure and compared them with 254 control children with HIV but no seizures. Early treatment with ART was associated with a significant reduction in the odds of seizures [odds ratio (OR) 0.04, 95% confidence interval: 0.02 to 0.09; P < 0.001]. Having an undetectable viral load at the time of enrollment was strongly protective against seizures (OR 0.03, P < 0.001), whereas history of World Health Organization Stage 4 disease (OR 2.2, P = 0.05) or CD4 count <200 cells/mm 3 (OR 3.6, P < 0.001) increased risk of seizures.

CONCLUSIONS

Early initiation of ART and successful viral suppression would likely reduce much of the excess seizure burden in children with HIV.

Accelerated neurodegeneration of basal forebrain cholinergic neurons in HIV-1 gp120 transgenic mice: Critical role of the p75 neurotrophin receptor

Human Immunodeficiency Virus-1 (HIV) infection of the brain induces HIV-associated neurocognitive disorders (HAND). The set of molecular events employed by HIV to drive cognitive impairments in people living with HIV are diverse and remain not completely understood. We have shown that the HIV envelope protein gp120 promotes loss of synapses and decreases performance on cognitive tasks through the p75 neurotrophin receptor (p75NTR). This receptor is abundant on cholinergic neurons of the basal forebrain and contributes to cognitive impairment in various neurological disorders. In this study, we examined cholinergic neurons of gp120 transgenic (gp120tg) mice for signs of degeneration. We observed that the number of choline acetyltransferase-expressing cells is decreased in old (12-14-month-old) gp120tg mice when compared to age matched wild type. In the same animals, we observed an increase in the levels of pro-nerve growth factor, a ligand of p75NTR, as well as a disruption of consolidation of extinction of conditioned fear, a behavior regulated by cholinergic neurons of the basal forebrain. Both biochemical and behavioral outcomes of gp120tg mice were rescued by the deletion of the p75NTR gene, strongly supporting the role that this receptor plays in the neurotoxic effects of gp120. These data indicate that future p75NTR-directed pharmacotherapies could provide an adjunct therapy against synaptic simplification caused by HIV.

Recent advances in HIV-associated neurocognitive disorders: a focus on older adults and sub-Saharan Africa

PURPOSE OF REVIEW

We reviewed recent literature on prevalence and interventional approaches for cognitive impairment in the context of HIV infection alongside current controversies and challenges around its nomenclature, screening, and diagnosis.

RECENT FINDINGS

Prevalence estimates for HIV-associated neurocognitive disorder (HAND) indicate that HAND remains highly prevalent despite combination antiretroviral treatment (cART) widely used. The available data are heterogeneous, particularly in sub-Saharan Africa (SSA) where recent reviews indicate substantial heterogeneity, wide prevalence estimates and lack of data from the majority SSA countries, despite them currently experiencing the greatest burden worldwide of both HIV and HAND.Several alternative approaches to diagnosis and classification of cognitive impairment in HIV have been published, taking into account changing clinical phenotypes.

SUMMARY

Cognitive impairment remains a significant challenge in the care of people living with HIV despite advances in treatment. Ongoing controversies exist around nomenclature and classification, screening measures, and the phenotype and aetiology of observed impairments. Two current areas of research priority and focus include understanding current phenotypes of individuals living and ageing with treated HIV and differing levels of risk for HAND in these phenotypes, alongside the effects of commonly occurring comorbidities.The current evidence base for interventional approaches is limited, but growing. The most promising avenues appear to be multidisciplinary. These are currently focussed on high income settings rather than SSA where the majority of people living with HIV, and affected by cognitive impairment in the context of HIV, currently reside.

Latent Profile Analysis of Cognitive Performance and Depressive Symptoms Among People with HIV

Depression and cognitive impairment are prevalent conditions among people with HIV (PWH), likely attributable to shared causes and common risk factors. Identifying subtypes of PWH with similar patterns of neurocognitive impairment (NCI) and depressive symptoms may inform development of patient-centered interventions that target-specific profiles. This study aimed to (1) classify PWH based on patterns of domain-specific NCI and depression; and (2) determine the relationship between latent class membership and pertinent clinical characteristics. PWH (N = 580, 86.2% male, 57.1% non-Hispanic White, 69.2% unemployed) completed a comprehensive neuropsychological test battery assessing global and domain-specific cognition. Domain-specific NCI was classified as deficit score >0.5. Participants completed the Beck Depression Inventory-II (BDI-II), and domain-specific BDI-II scores reflecting cognitive, affective, and somatic symptoms were computed. Latent profile analysis (LPA) was used to determine latent subgroups of NCI and depression. The optimal LPA solution consisted of five classes: minimal NCI and minimal depression (Class 1), amnestic and minimal depression (Class 2), severe multi-domain NCI and moderate depression (somatic and affective; Class 3), mild NCI and mild depression (Class 4), and moderate multi-domain NCI and severe depression (Class 5). Despite similar levels of functional impairment, Class 5 had a significant psychiatric profile, whereas Class 3 had a complex medical profile (i.e., higher frailty index, higher medications, greater proportion of AIDS diagnosis). In contrast, Class 1 had the lowest medication use and frailty index, with similar HIV disease characteristics to Classes 3 and 5. Our results suggest there are multiple pathways to cognitive and functional impairment among PWH with co-occurring depression and cognitive impairment, and these groups may respond differently to interventions. Of note, our sample was majority non-Hispanic White and male, which is nonrepresentative of the US population of PWH. Future interventions should consider a more integrated, person-centered approach that addresses cognitive and emotional health to optimize health outcomes in PWH.

Identifying and distinguishing cognitive profiles among virally suppressed people with HIV

OBJECTIVE

Cognitive deficits are common among people with HIV (PWH), even when virally suppressed. We identified cognitive profiles among virally suppressed PWH and determined how sociodemographic, clinical/behavioral, and HIV disease characteristics distinguish profile membership.

METHOD

Participants included 704 virally suppressed PWH (Mage = 43.9 [SD = 10.2], 88% male, 58.9% non-Hispanic White) from the HIV Neurobehavioral Research Program. Demographically adjusted T scores were derived from a neuropsychological evaluation comprised of 13 tests. We implemented a pipeline involving dimension reduction and clustering to identify profiles of cognitive performance. Random forest models on a 70/30 training/testing set with internal cross-validation were used to identify sociodemographic, clinical/behavioral, and HIV disease correlates of profile membership.

RESULTS

Six cognitive profiles were identified: (a) "unimpaired" (19.9%); (b) weakness in verbal learning and memory (15.5%); (c) weakness in executive function and learning (25.8%); (d) weakness in motor, processing speed, and executive function (8.1%); (e) impaired learning and recall with weak-to-impaired motor, processing speed, and executive function (13.1%); (f) global deficits (17.6%). The most discriminative sociodemographic, clinical/behavioral, and HIV disease characteristics varied by profile with self-reported mood symptoms and cognitive/functional difficulties (e.g., language/communication, memory, and overall everyday function complaints) most consistently associated with profile membership.

CONCLUSIONS

Cognitive profiles and their associated factors among PWH are heterogeneous, but learning/memory deficits were most common and self-reported mood, and cognitive/functional difficulties were most consistently related to profile membership. This heterogeneity in cognitive profiles and their correlates in PWH suggests that differing mechanisms contribute to cognitive deficits and, thus, underscores the need for personalized risk reduction and therapeutic strategies among PWH. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Effects of acute Δ9-tetrahydrocannabinol on behavior and the endocannabinoid system in HIV-1 Tat transgenic female and male mice

Cannabis use is highly prevalent especially among people living with HIV (PLWH). Activation of the anti-inflammatory and neuroprotective endocannabinoid system by phytocannabinoids, i.e. Δ9-tetrahydrocannabinol (THC), has been proposed to reduce HIV symptoms. However, THC's effects on HIV-related memory deficits are unclear. Using HIV-1 Tat transgenic mice, the current study investigates acute THC effects on various behavioral outcomes and the endocannabinoid system. For the rodent tetrad model, THC doses (1, 3, 10 mg/kg) induced known antinociceptive effects, with Tat induction increasing antinociceptive THC effects at 3 and 10 mg/kg doses. Only minor or no effects were noted for acute THC on body temperature, locomotor activity, and coordination. Increased anxiety-like behavior was found for females compared to males, but acute THC had no effect on anxiety. Object recognition memory was diminished by acute THC in Tat(-) females but not Tat(+) females, without affecting males. The endocannabinoid system and related lipids were not affected by acute THC, except for THC-induced decreases in CB1R protein expression levels in the spinal cord of Tat(-) mice. Female sex and Tat induction was associated with elevated 2-AG, AEA, AA, CB1R, CB2R, FAAH and/or MAGL expression in various brain regions. Further, AEA levels in the prefrontal cortex of Tat(+) females were negatively associated with object recognition memory. Overall, findings indicate that acute THC exerts differential effects on antinociception and memory, dependent on sex and HIV Tat expression, potentially in relation to an altered endocannabinoid system, which may be of relevance in view of potential cannabis-based treatment options for PLWH.

HIV and COVID-19: two pandemics with significant (but different) central nervous system complications

Human immunodeficiency virus (HIV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cause significant neurologic disease. Central nervous system (CNS) involvement of HIV has been extensively studied, with well-documented invasion of HIV into the brain in the initial stage of infection, while the acute effects of SARS-CoV-2 in the brain are unclear. Neuropathologic features of active HIV infection in the brain are well characterized whereas neuropathologic findings in acute COVID-19 are largely non-specific. On the other hand, neuropathologic substrates of chronic dysfunction in both infections, as HIV-associated neurocognitive disorders (HAND) and post-COVID conditions (PCC)/long COVID are unknown. Thus far, neuropathologic studies on patients with HAND in the era of combined antiretroviral therapy have been inconclusive, and autopsy studies on patients diagnosed with PCC have yet to be published. Further longitudinal, multidisciplinary studies on patients with HAND and PCC and neuropathologic studies in comparison to controls are warranted to help elucidate the mechanisms of CNS dysfunction in both conditions.

Infectious leukoencephalopathies

Leukoencephalopathy from infectious agents may have a rapid course, such as human simplex virus encephalitis; however, in many diseases, it may take months or years before diagnosis, such as in subacute sclerosing panencephalitis or Whipple disease. There are wide geographic distributions and susceptible populations, including both immunocompetent and immunodeficient patients. Many infections have high mortality rates, such as John Cunningham virus and subacute sclerosing panencephalitis, although others have effective treatments if suspected and treated early, such as herpes simplex encephalitis. This chapter will describe viral, bacterial, and protozoal infections, which predominantly cause leukoencephalopathy. We focus on the clinical presentation of these infectious agents briefly covering epidemiology and subtypes of infections. Next, we detail current pathophysiologic mechanisms causing white matter injury. Diagnostic and confirmatory tests are discussed. We cover predominantly MRI imaging features of leukoencephalopathies, and in addition, summarize the common imaging features. Additionally, we detail how imaging features may be used to narrow the differential of a leukoencephalopathy clinical presentation. Lastly, we present an outline of common treatment approaches where available.

The mediation effect of treatment fatigue in the association between memory and health-related quality of life in men with HIV who have sex with men

Approximately half of all adults living with the Human Immunodeficiency Virus (HIV) experience cognitive alterations related to difficulties in treatment adherence and, therefore, to a significant decrease in quality of life. In this sense, new studies are needed to identify potential mediators related to treatment in this association, such as treatment fatigue. This fact is especially important in at specific groups of individuals with HIV, namely men with HIV who have sex with men (MSM). The objective of this study was to analyze the association between cognitive functioning, Health-Related Quality of Life (HRQoL), and treatment fatigue in MSM with HIV. A cross-sectional study was developed with a sample of 70 MSM, from the Infectious Diseases Unit of the General University Hospital of Alicante (Spain). Participants completed questionnaires related to sociodemographic data, HRQoL, and treatment fatigue in an initial phase; in a second phase, they were administered a computerized cognitive evaluation. Our results demonstrate a significant relationship between a lower cognitive performance in the memory domain and worse HRQoL. Mediation analysis has revealed the total mediation effect of treatment fatigue, specifically, the treatment cynicism domain, on this relationship. This mediation effect remained significant after controlling the sociodemographic and clinical HIV-related variables in the model. No significant mediation effects of the rest of evaluated cognitive domains (attention, perception, reasoning, or coordination) were found in this relationship. The results of this study highlight how MSM with a significant deterioration of memory are at greater risk of developing high levels of treatment fatigue, and, therefore, a lower adherence to the same and a significant deterioration in their HRQoL.

Dysregulated neuroimmune interactions and sustained type I interferon signaling after human immunodeficiency virus type 1 infection of human iPSC derived microglia and cerebral organoids

Human immunodeficiency virus type-1 (HIV-1) associated neurocognitive disorder (HAND) affects up to half of HIV-1 positive patients with long term neurological consequences, including dementia. There are no effective therapeutics for HAND because the pathophysiology of HIV-1 induced glial and neuronal functional deficits in humans remains enigmatic. To bridge this knowledge gap, we established a model simulating HIV-1 infection in the central nervous system using human induced pluripotent stem cell (iPSC) derived microglia combined with sliced neocortical organoids. Upon incubation with two replication-competent macrophage-tropic HIV-1 strains (JRFL and YU2), we observed that microglia not only became productively infected but also exhibited inflammatory activation. RNA sequencing revealed a significant and sustained activation of type I interferon signaling pathways. Incorporating microglia into sliced neocortical organoids extended the effects of aberrant type I interferon signaling in a human neural context. Collectively, our results illuminate the role of persistent type I interferon signaling in HIV-1 infected microglial in a human neural model, suggesting its potential significance in the pathogenesis of HAND.

Antiretroviral Therapy Intensification for Neurocognitive Impairment in Human Immunodeficiency Virus

BACKGROUND

Neurocognitive impairment (NCI) in people with HIV (PWH) on antiretroviral therapy (ART) is common and may result from persistent HIV replication in the central nervous system.

METHODS

A5324 was a randomized, double-blind, placebo-controlled, 96-week trial of ART intensification with dolutegravir (DTG) + MVC, DTG + Placebo, or Dual - Placebo in PWH with plasma HIV RNA <50 copies/mL on ART and NCI. The primary outcome was the change on the normalized total z score (ie, the mean of individual NC test z scores) at week 48.

RESULTS

Of 357 screened, 191 enrolled: 71% male, 51% Black race, 22% Hispanic ethnicity; mean age 52 years; mean CD4+ T-cells 681 cells/µL. Most (65%) had symptomatic HIV-associated NC disorder. Study drug was discontinued due to an adverse event in 15 (8%) and did not differ between arms (P = .17). Total z score, depressive symptoms, and daily functioning improved over time in all arms with no significant differences between them at week 48 or later. Adjusting for age, sex, race, study site, efavirenz use, or baseline z score did not alter the results. Body mass index modestly increased over 96 weeks (mean increase 0.32 kg/m2, P = .006) and did not differ between arms (P > .10).

CONCLUSIONS

This is the largest, randomized, placebo-controlled trial of ART intensification for NCI in PWH. The findings do not support empiric ART intensification as a treatment for NCI in PWH on suppressive ART. They also do not support that DTG adversely affects cognition, mood, or weight.

Management Practice and Clinical Outcomes of Dementia in Sub-Saharan Africa: A Systematic Review

Background

Dementia is a severe neurodegenerative disorder and it is a group of acquired symptoms associated with impaired cognitive functions. In low-income settings particularly in Sub-Saharan Africa (SSA), it is often seen as part of normal aging. Environmental, behavioral, and lifestyle interventions have the potential to alter the disease course of dementia.

Objective

This study is aimed to synthesize the literature/evidence(s) on the management practice and treatment outcomes of dementia in SSA.

Method

Comprehensive literature was searched in PubMed database, Cochrane Library, and Google Scholar. Eligibility has been set, and based on the criteria, initially, a total of 442 results were obtained, and from those around 183 articles were duplicated. After examining titles and abstracts of records 26 articles were identified. Finally, five randomized clinical trials (RCT) and three prospective cohort studies that were reported on the management practice and treatment outcome of dementia in SSA were eligible for analysis. RCT and prospective cohort studies were used to strengthen the quality of evidence. The quality of the included RCT studies was assessed by using the Cochrane Risk of Bias Tool.

Result

A total of 2781 patient data were included in the final analysis. Of these, 2354 patients were obtained from 5 RCTs and 427 patients from 3 prospective cohort studies, which were conducted in SSA countries. RCT studies were done on the feasibility and clinical effectiveness of cognitive stimulation therapy (CST) showed improvements in language memory domains and physical health. In addition, studies that focus on the management of human immunodeficiency virus-associated dementia (HIVAD) were reported to improve neurocognitively.

Conclusion

CST is applicable in low-resource settings and it shows improvements in cognitive function and quality of life. Early initiation of combination antiretroviral therapy in resource-limited settings has been associated with improvement in the cognitive function of HIVAD.

Effects of Morphine on Gp120-induced Neuroinflammation Under Immunocompetent Vs. Immunodeficient Conditions

HIV-associated neurocognitive disorder (HAND) is a common complication of HIV infection, whose development is known to be facilitated by inflammation and exacerbated by morphine. Previously, using the gp120 transgenic (tg) mouse model in combination with LP-BM5 (a murine retrovirus that can cause systemic immunodeficiency in susceptible mouse strains) we demonstrated differential gp120-associated central nervous system (CNS) neuroinflammatory responses under immunocompetent (-LP-BM5) vs. immunocompromised (+LP-BM5) conditions. Here, we further investigated the effects of morphine on gp120-associated neuroinflammatory response within the hippocampus under differential immune status. First, we confirmed that morphine treatment (2 × 25 mg pellets) did not significantly affect the development of immunodeficiency induced by LP-BM5 and all brain regions examined (hippocampus, striatum, and frontal lobe) had detectable LP-BM5 viral gag genes. Morphine notably reduced the performance of gp120tg+ mice in the alteration T-maze assay when 2-minute retention was used, regardless of LP-BM5 treatment. Morphine further enhanced GFAP expression in gp120tg+ mice regardless of host immune status, while promoted CD11b expression only in immunocompetent mice, regardless of gp120tg expression. In immunocompetent gp120tg+ mice, morphine increased the RNA expression of CCL2, CCL5, CXCL10, IL-12p40, and IFNβ; while under the immunodeficient condition, morphine downregulated the expression of CCL2, CCL5, CXCL10, IL-12p40, and IL-1β. Further, expression of TNFα and IFNγ were enhanced by morphine regardless of host immune status. Altogether, our results suggest that the effects of morphine are complex and dependent on the immune status of the host, and host immune status-specific, targeted anti-neuroinflammatory strategies are required for effective treatment of HAND.

Serum inflammation markers associated with altered brain white matter microstructure in people with HIV on antiretroviral treatment

BACKGROUND

Many studies have reported reduced brain white matter fractional anisotropy (FA) and increased mean diffusivity (MD) on diffusion tensor imaging (DTI) of people with HIV (PWH). Few, however, have linked individual blood inflammatory markers with white matter tract-specific FA and MD.

METHODS

PWH 50 years old or older from New York, NY, USA, were invited to a cross-sectional study. Demographic data, blood samples, and brain DTI were obtained. Least absolute shrinkage and selection operator (LASSO) regression was used to examine associations between biomarkers and white matter tract-specific FA and MD. All models included age, sex, race, ethnicity, diabetes, hypertension, smoking, and viral load as control variables.

RESULTS

Seventy-two cases were analyzed. Mean age was 60 ± 6 years, 47% were women, 21% were Hispanic, and 78% were black. All had asymptomatic HIV infection and were on antiretroviral therapy. Eighty-nine percent had CD4 count >200 cell/mm3 and 78% were virally suppressed. Vascular endothelial growth factor (VEGF) and macrophage inflammatory proteins (MIP) 1β and 1α were consistently associated with lower FA and higher MD across white matter tracts.

CONCLUSIONS

Elevated serum VEGF, MIP-1α, and MIP-1β were associated with altered white matter microstructure. These blood biomarkers may help predict HIV-associated white matter damage.

Role of non-classical monocytes in HIV-associated vascular cognitive impairment

Despite antiretroviral treatment (cART), people living with HIV (PLWH) are more susceptible to neurocognitive impairment (NCI), probably due to synergistic/additive contribution of traditional cerebrovascular risk factors. Specifically, altered blood brain barrier (BBB) and transmigration of inflammatory monocytes are risk factors for developing cerebral small vessel disease (CSVD). In order to investigate if inflammatory monocytes exacerbate CSVD and cognitive impairment, 110 PLWH on cART and 110 age-, sex- and Reynold’s cardiovascular risk score-matched uninfected individuals were enrolled. Neuropsychological testing, brain magnetic resonance imaging and whole blood analyses to measure platelet-monocyte interaction and monocyte, endothelial activation were performed. Results demonstrated that PLWH exhibited increased levels of platelet-monocyte complexes (PMCs) and higher expression of activation molecules on PMCs. PLWH with CSVD had the poorest cognitive performance and the highest circulating levels of non-classical monocytes which exhibited significant inverse correlation with each other. Furthermore, markers of monocyte and endothelium activation were significantly positively correlated indicating BBB impairment. Our results confirm that interaction with platelets activates and drives monocytes towards an inflammatory phenotype in PLWH. In particular, elevated levels of non-classical monocytes may represent a common pathway to neuroinflammation, CSVD and subsequent cognitive impairment, warranting further longitudinal studies to evaluate responsiveness of this potential biomarker.

Circulating endothelial and angiogenic cells predict hippocampal volume as a function of HIV status

Circulating endothelial cells (CECs) and myeloid angiogenic cells (MACs) have the capacity to stabilize human blood vessels in vivo. Evidence suggests that these cells are depleted in dementia and in persons living with HIV (PWH), who have a higher prevalence of dementia and other cognitive deficits associated with aging. However, the associations of CECs and MACs with MRI-based measures of aging brain health, such as hippocampal gray matter volume, have not been previously demonstrated. The present study examined differences in these associations in 51 postmenopausal women with and without HIV infection. Gray matter volume was quantified using MRI. CECs and MACs were enumerated using fluorescence-activated cell sorting. Analyses examined the association of these cell counts with left and right hippocampal gray matter volume while controlling for age and hypertension status. The main finding was an interaction suggesting that compared to controls, postmenopausal PWH with greater levels of CECs and MACs had significantly greater hippocampus GMV. Further research is necessary to examine potential underlying pathophysiological mechanisms in HIV infection linking morpho-functional circulatory reparative processes with more diminished hippocampal volume in postmenopausal women.

Nanosystems for gene therapy targeting brain damage caused by viral infections

Several human pathogens can cause long-lasting neurological damage. Despite the increasing clinical knowledge about these conditions, most still lack efficient therapeutic interventions. Gene therapy (GT) approaches comprise strategies to modify or adjust the expression or function of a gene, thus providing therapy for human diseases. Since recombinant nucleic acids used in GT have physicochemical limitations and can fail to reach the desired tissue, viral and non-viral vectors are applied to mediate gene delivery. Although viral vectors are associated to high levels of transfection, non-viral vectors are safer and have been further explored. Different types of nanosystems consisting of lipids, polymeric and inorganic materials are applied as non-viral vectors. In this review, we discuss potential targets for GT intervention in order to prevent neurological damage associated to infectious diseases as well as the role of nanosized non-viral vectors as agents to help the selective delivery of these gene-modifying molecules. Application of non-viral vectors for delivery of GT effectors comprise a promising alternative to treat brain inflammation induced by viral infections.

Factors associated with verbal fluency in older adults living with HIV in West Africa: A longitudinal study

OBJECTIVE

Verbal fluency decline, observed both in aging and HIV infection, has been related to lower quality of life. This study aimed to evaluate the factors associated with categorical fluency in people living with HIV (PLHIV) aged ≥60 years living in West Africa.

METHODS

In this longitudinal study, PLHIV aged ≥60 years, on antiretroviral therapy (ART) for ≥6 months were included in three clinics (two in Côte d'Ivoire, one in Senegal) participating in the West Africa International epidemiological Databases to Evaluate AIDS (IeDEA) collaboration. Categorical fluency was evaluated with the Isaacs Set Test at 60 s at baseline and 2 years later. Factors associated with verbal fluency baseline performance and annual rates of changes were evaluated using multivariate linear regression models.

RESULTS

Ninety-seven PLHIV were included with 41 of them (42%) having a 2-year follow-up visit. The median age was 64 (62-67), 45.4% were female, and 89.7% had an undetectable viral load. The median annual change in categorical fluency scores was -0.9 (IQR: -2.7 to 1.8). Low baseline categorical fluency performance and its decline were associated with older age and being a female. Low educational level was associated with low baseline categorical fluency performance but not with its decline. Categorical fluency decline was also associated with marital status and hypertension.

CONCLUSIONS

Among older West African PLHIV, usual socio-demographic variables and hypertension were the main factors associated with low categorical fluency performance and/or its decline. Interventions that focus on supporting cardiometabolic health are highly recommended to prevent cognitive disorders in PLHIV.

Health-Related Quality of Life in People Living With HIV With Cognitive Symptoms: Assessing Relevant Domains and Associations

This study aimed to validate and assess a comprehensive set of illness-specific health-related quality of life (HRQL) domains in people living with HIV (PLWH) with cognitive symptoms. One hundred and three HIV patients with cognitive symptoms (n = 93 male, 90.3%) were identified from two UK HIV clinics and complete a series of validated scales measuring seven HRQL domains identified as important to HRQL by PLWH with cognitive impairment. These included: physical functioning, cognition, social connectedness, self-concept, HIV stigma, acceptance of and perceived control over cognitive health, and physical and mental health and wellbeing. Exploratory factor analysis confirmed that domain total scores loaded onto one main factor, representing HRQL. Scale cut-off scores revealed a significant proportion of patients scored outside the normal range on single domains (between 26.2% and 79.6%), and many patients on multiple domains (40.8% on 4 or more domains). We found evidence of poor HRQL across domains in the majority of PLWH with cognitive symptoms and identified domains driving these experiences. This provides targets for intervention development and clinical action to maintain or improve HRQL in PLWH with cognitive symptoms or impairment.

Declining Prevalence of Human Immunodeficiency Virus (HIV)-Associated Neurocognitive Disorders in Recent Years and Associated Factors in a Large Cohort of Antiretroviral Therapy-Treated Individuals With HIV

BACKGROUND

HIV-associated neurocognitive disorders (HAND) have been suggested as persistent even with effective antiretroviral therapy (ART). Aims were to evaluate HAND prevalence and associated factors, in a large cohort of people-with-HIV (PWH).

METHODS

ART-treated PWH, underwent a neuropsychological examination through a battery of 12 tests exploring 5 different domains, between 2009 and 2020, were included in this cross-sectional analysis. HAND were classified according to Frascati's criteria. Participants were defined as complaining or not-complaining if a cognitive complaint was reported or not. Chi-square for trend and multivariable logistic regression were fitted.

RESULTS

Overall, 1424 PWH were enrolled during four three-years periods. HAND prevalence was 24%; among complainers (572/1424), it was 38%, higher than among not-complainers (15%). Over the study period, a decreasing HAND prevalence was found in the entire population (P < 0.001) and in complaining (P < 0.001); in not-complaining it remained stable (P = 0.182). Factors associated with HAND were older age, lower educational level, lower current CD4+ T-cell count and HCV co-infection. Compared to nonnucleoside reverse transcriptase inhibitors, receiving dual and integrase strand transfer inhibitor (INSTI)-based therapies was associated with a decreased risk of HAND, as well as being tested in more recent years.

CONCLUSIONS

In this large cohort of ART-treated PWH, mostly virologically suppressed, a remarkable decreasing HAND prevalence was observed. Besides HIV- and patient-related factors, the reduced risk of HAND found with dual and INSTI-based regimens along with a more recent ART initiation, could suggest a potential role of new treatment strategies in this decline, due to their greater virologic efficacy and better tolerability.

The potential role of HIV-1 latency in promoting neuroinflammation and HIV-1-associated neurocognitive disorder

Despite potent suppression of HIV-1 viral replication in the central nervous system (CNS) by antiretroviral therapy (ART), between 15% and 60% of HIV-1-infected patients receiving ART exhibit neuroinflammation and symptoms of HIV-1-associated neurocognitive disorder (HAND) - a significant unmet challenge. We propose that the emergence of HIV-1 from latency in microglia underlies both neuroinflammation in the CNS and the progression of HAND. Recent molecular studies of cellular silencing mechanisms of HIV-1 in microglia show that HIV-1 latency can be reversed both by proinflammatory cytokines and by signals from damaged neurons, potentially creating intermittent cycles of HIV-1 reactivation and silencing in the brain. We posit that anti-inflammatory agents that also block HIV-1 reactivation, such as nuclear receptor agonists, might provide new putative therapeutic avenues for the treatment of HAND.

Exploring HIV-Associated Neurocognitive Impairment in the Era of Effective Antiretroviral Therapy: A Primary Healthcare Perspective

The prevalence of HIV-associated neurocognitive impairment (H-NCI) is concerning. Individuals on effective antiretroviral therapy (ART) may still be at risk for H-NCI as they experience longer life expectancies. There are, however, few professionals with knowledge and skills to identify H-NCI, in low- and middle-income countries. We explored qualitatively, primary healthcare workers' knowledge and views of H-NCI, in the era of effective ART, particularly their views toward task-sharing of H-NCI screening from specialists to mid-level or lay healthcare providers. The first phase of data collection involved two focus group discussions (FGDs) 23 primary healthcare workers from two facilities in the Western Cape participated in the FGDs. In the second phase of data collection12 individual, in-depth interviews were conducted in KwaZulu-Natal. Using thematic analysis, several key themes emerged. Although healthcare providers were unable to specifically identify H-NCI, they described several HIV disease and treatment related or mental health comorbidities that could be responsible for the symptoms. Despite healthcare workers reporting low frequencies of H-NCI, they favoured receiving training to screen for H-NCI with a view toward providing holistic care.

The role of CCR5 in HIV-associated neurocognitive disorders

While combination antiretroviral therapy (cART) has successfully increased the lifespan of individuals infected with HIV, a significant portion of this population remains affected by HIV-associated neurocognitive disorder (HAND). C-C chemokine receptor 5 (CCR5) has been well studied in immune response and as a co-receptor for HIV infection. HIV-infected (HIV⁺) patients experienced mild to significant amelioration of cognitive function when treated with different CCR5 antagonists, including maraviroc and cenicriviroc. Consistent with clinical results, Ccr5 knockout or knockdown rescued cognitive deficits in HIV animal models, with mechanisms of reduced microgliosis and neuroinflammation. Pharmacologic inhibition of CCR5 directly improved cerebral and hippocampal neuronal plasticity and cognitive function. By summarizing the animal and human studies of CCR5 in HIV-associated cognitive deficits, this review aims to provide an overview of the mechanistic role of CCR5 in HAND pathophysiology. This review also discusses the addition of CCR5 antagonists, such as maraviroc, to cART for targeted prevention and treatment of cognitive impairments in patients infected with HIV.

Screening Accuracy of Mini Addenbrooke's Cognitive Examination Test for HIV-Associated Neurocognitive Disorders in People Ageing with HIV

Aging and increased cardiovascular risk are major drivers for HIV-associated neurocognitive disorders (HAND), for which accurate screenings are lacking. Mini-Addenbrooke's Cognitive Examination (MACE) reliably detects vascular and neurodegenerative cognitive decline among HIV-negative patients. We evaluated MACE diagnostic accuracy in detecting HAND in people living with HIV (PLWH) and we compared it with the International HIV Dementia Scale (IHDS). A single-centre double-blind study of diagnostic accuracy on adult outpatient PLWH without neurocognitive confounding was performed. MACE and IHDS were administered in 5 and 10 min by clinicians, followed by the reference standard battery (14 tests) by neuropsychologists. HAND diagnosis was based on the modified version of Frascati's criteria by Gisslén to reduce false positives. Exploratory cut-offs were evaluated for MACE. Diagnostic accuracy and clinical utility parameters were assessed. 231 patients were enrolled. 75.7% men with a median age, education, and length of infection of 54 (48-59), 10 (8-13) and 16 (5-25) years. HAND prevalence was 48.5% (38.9% asymptomatic impairment). Compared to IHDS, MACE sensitivity (89.3% vs 70.5%), specificity (94.1% vs 63.0%), correct classification rate (86.5% vs 66.7%), J index (0.83 vs 0.34), AUROC (0.97 vs 0.79), agreement with the gold standard (k 0.84 vs 0.33) and effect size in distinguishing HAND vs non-HAND (d 2.11 vs 1.15) were higher. Among PLWH aged 65 years and above (n = 37) MACE performance was consistently better than IHDS. The quick and easy-to-perform MACE could possess an accurate and useful screening performance for HAND in otherwise neurocognitively healthy cohorts of PLWH.

Childhood trauma and genetic variation in the DAT 40-bp VNTR contribute to HIV-associated neurocognitive disorders

HIV/AIDS is a major public health burden in South Africa, currently affecting an estimated 13.5% of the population. Despite improved access to antiretroviral therapies, HIV-associated neurocognitive disorders (HAND), characterised by a spectrum of neurocognitive impairment, emotional disturbances and motor abnormalities, continue to persist. Gene-environment interactions contribute to HAND pathophysiology and previous research has identified childhood trauma as an environmental risk factor. Dopaminergic signalling in the prefrontal cortex plays a key role in cognitive function. Thus, variants in genes encoding the dopamine transporter (DAT) and catechol-O-methyltransferase (COMT), which are responsible for dopamine transport and metabolism, could represent genetic risk factors for HAND. This study investigated whether the DAT variable number of tandem repeats (VNTR) and COMT Val158Met (rs4680) polymorphisms are associated with longitudinal change in cognitive function in the context of childhood trauma and HIV. Participants (n = 49 HIV-negative and n = 64 HIV-positive women) completed the Childhood Trauma Questionnaire - Short Form (CTQ-SF) and provided blood for genetic analyses. Global cognitive scores were generated from baseline and one-year follow-up assessments. Following polymerase chain reaction, genotypes were determined using gel electrophoresis and confirmed by Sanger sequencing. Baseline global cognitive scores, genotype, HIV status and CTQ-SF scores were regressed on one-year global cognitive scores in regression models. Analysis of variance was used to examine the effect of including predictor variable interactions on model fit. HIV seropositivity was associated with poorer cognitive performance at one-year follow-up (p = 2.46 ×10-4). The combination of HIV and DAT 10-repeat homozygosity (DAT 10/10) was associated with reduced global cognitive scores in longitudinal models (p = 0.010). Including the interaction between DAT 10/10, childhood trauma, and HIV explained significantly more of the variance in longitudinal cognitive scores (p = 0.008). There were no significant associations with the COMT genotype. Our research indicates that childhood trauma and genetic variation in DAT contribute toward the aetiology of HAND. Future studies in larger cohorts are warranted to verify these results.

Impact of HIV-associated cognitive impairment on functional independence, frailty and quality of life in the modern era: a meta-analysis

HIV-associated neurocognitive disorder (HAND) is an important sequela of HIV infection. Combined antiretroviral therapy (cART) has improved the health outcomes of many people living with HIV but has given rise to a less severe but limiting form of HAND. The study aimed to evaluate the impact of HAND on medication adherence, activities of daily living (ADL), quality of life and frailty. This systematic review adheres to the guidelines for Preferred Reporting Items for Systematic Reviews and Meta-Analyses. We searched MEDLINE, PubMed, CINAHL, Academic Search Complete, and PsycINFO online databases. Studies were included if they examined the relationship between HAND and medication adherence, ADL, quality of life and frailty, and were conducted between 1997 and 2021. We used a random-effects meta-analysis model to assess the impact of HAND on outcome variables. Forty papers, totaling 11,540 participants, were included in the narrative and quantitative syntheses. Cognitive impairment was associated with poorer medication adherence (r = 0.601, CI 0.338 to 0.776, p = 0.001, I² = 94.66). Cognitive impairment did not influence ADL (r = 0.167, CI-0.215 to 0.505, p = 0.393) and quality of life (r = 0.244, CI 0.117 to 0.548, p = 0.182). In the cART era, HAND appears to be associated with adherence to medication, which may influence future health outcomes. In PLWHIV who are adherent to cART, cognitive impairment does not appear to interfere with ADL and quality of life.

M, Michelle. H, Anna. D, Reuben. R, Greg. K, Andre. JJ, Leslie L, Thomas. M, GF. TK. Impact of HIV on Cognitive Performance in Professional Drivers

BACKGROUND

The intellectually demanding modern workplace is often dependent on good cognitive health, yet there is little understanding of how neurocognitive dysfunction related to HIV presents in employed individuals working in high-risk vocations such as driving. HIV-associated neurocognitive impairment is also associated with poorer long-term cognitive, health, and employment outcomes.

SETTING

This study, set in Cape Town, South Africa, assessed the effects of HIV on neuropsychological test performance in employed male professional drivers.

METHOD

We administered a neuropsychological test battery spanning 7 cognitive domains and obtained behavioral data, anthropometry, and medical biomarkers from 3 groups of professional drivers (68 men with HIV, 55 men with cardiovascular risk factors, and 81 controls). We compared the drivers' cognitive profiles and used multiple regression modeling to investigate whether between-group differences persisted after considering potentially confounding sociodemographic and clinical variables (ie, income, home language, depression, and the Framingham risk score).

RESULTS

Relative to other study participants, professional drivers with HIV performed significantly more poorly on tests assessing processing speed (P < 0.003) and attention and working memory (P = 0.018). Group membership remained a predictor of cognitive performance after controlling for potential confounders. The cognitive deficits observed in men with HIV were, however, largely characterized as being mild or asymptomatic. Consistent with this characterization, their relatively poor performance on neuropsychological testing did not generalize to self-reported impairment on activities of daily living.

CONCLUSION

Drivers with HIV may be at risk of poorer long-term health and employment outcomes. Programs that monitor and support their long-term cognitive health are needed.

Comparison of dementia incidence and prevalence between individuals with and without HIV infection in primary care from 2000 to 2016

OBJECTIVE

To compare dementia incidence and prevalence after age 50 years by HIV status.

DESIGN

Observational cohort, 2000-2016.

METHODS

People with HIV (PWH) on antiretroviral therapy (ART) and demographically similar people without HIV (PWoH), all aged 50 years and older, were identified from Kaiser Permanente healthcare systems in Northern California, Southern California, and Mid-Atlantic States (Maryland, Virginia, Washington DC). Dementia diagnoses were obtained from electronic health records. Incidence and prevalence of dementia, overall and by time period (i.e. 2000-2002, 2003-2004, …, 2015-2016), were calculated using Poisson regression. Trends were examined using Joinpoint regression. Rate ratios were used to compare dementia by HIV status with adjustment for sociodemographics, substance use, and clinical factors.

RESULTS

The study included 13 296 PWH and 155 354 PWoH (at baseline: for both, mean age = 54 years, 89% men; for PWH, 80% with HIV RNA <200 copies/ml). From 2000 to 2016, overall incidence of dementia was higher among PWH [adjusted incidence rate ratio (aIRR) = 1.80, 95% confidence interval (CI) = 1.60-2.04]. Dementia incidence decreased among both PWH and PWoH (-8.0 and -3.1% per period, respectively) but remained higher among PWH in the most recent time period, 2015-2016 (aIRR = 1.58, 95% CI = 1.18-2.12). The overall prevalence of dementia from 2000 to 2016 was higher among PWH [adjusted prevalence ratio (aPR) = 1.86, 95% CI = 1.70-2.04] and was also higher among PWH in 2015-2016 (aPR = 1.75, 95% CI = 1.56-1.97).

CONCLUSION

Reductions in dementia incidence are encouraging and may reflect ART improvement, but PWH are still more likely to have dementia than PWoH. Monitoring the burden of dementia among PWH is important as this population ages.

Crucial Role of Central Nervous System as a Viral Anatomical Compartment for HIV-1 Infection

The chronic infection established by the human immunodeficiency virus 1 (HIV-1) produces serious CD4+ T cell immunodeficiency despite the decrease in HIV-1 ribonucleic acid (RNA) levels and the raised life expectancy of people living with HIV-1 (PLWH) through treatment with combined antiretroviral therapies (cART). HIV-1 enters the central nervous system (CNS), where perivascular macrophages and microglia are infected. Serious neurodegenerative symptoms related to HIV-associated neurocognitive disorders (HAND) are produced by infection of the CNS. Despite advances in the treatment of this infection, HAND significantly contribute to morbidity and mortality globally. The pathogenesis and the role of inflammation in HAND are still incompletely understood. Principally, growing evidence shows that the CNS is an anatomical reservoir for viral infection and replication, and that its compartmentalization can trigger the evolution of neurological damage and thus make virus eradication more difficult. In this review, important concepts for understanding HAND and neuropathogenesis as well as the viral proteins involved in the CNS as an anatomical reservoir for HIV infection are discussed. In addition, an overview of the recent advancements towards therapeutic strategies for the treatment of HAND is presented. Further neurological research is needed to address neurodegenerative difficulties in people living with HIV, specifically regarding CNS viral reservoirs and their effects on eradication.

Cardio-ankle vascular index of increased arterial wall stiffness is associated with neurocognitive impairment in well-controlled HIV

OBJECTIVES

HIV-associated neurocognitive disorders (HAND) remain prevalent in people living with HIV (PLWH) despite widespread use of combined antiretroviral therapy (ART). Vascular disease contributes to the pathogenesis of HAND, but traditional vascular risk factors do not fully explain the relation between vascular disease and HAND. A more direct measure of vascular dysfunction is needed. This cross-sectional study tested whether the cardio-ankle vascular index (CAVI), a novel method to assess arterial stiffness, is associated with HAND among PLWH.

METHODS

Participants included 75 non-diabetic adults with well-controlled HIV from an outpatient HIV clinic. We assessed the relation between CAVI and neurocognitive impairment (NCI). The latter was primarily characterized by the Frascati criteria and secondarily (post hoc) using the Global Deficit Score (GDS). Logistic regression models tested whether high CAVI (≥ 8) was independently associated with NCI when controlling for potential confounders.

RESULTS

Participants (M_age  = 45.6 ± 8.3 years; 30.1% male) had few traditional cardiovascular disease (CVD) risk factors (hypertension, n = 7; dyslipidaemia, n = 34; body mass index ≥ 25 kg/m² , n = 12; smoking history, n = 13; 2.2% mean 10-year risk of CVD or stroke). Twelve (16%) participants had high CAVI, which was independently associated with meeting Frascati criteria for NCI [n = 39, odds ratio (OR) = 7.6, p = 0.04], accounting for age, education, gender, income, CD4 nadir, recent CD4 and traditional CVD risk factors. High CAVI was also associated with NCI as reflected by higher GDS (OR = 17.4, p = 0.02).

CONCLUSIONS

Cardio-ankle vascular index is a promising measure of vascular dysfunction that may be independently associated with NCI in relatively healthy PLWH. Larger studies should test the utility of CAVI in predicting NCI/decline in PLWH.

Alzheimer Dementia in People Living With HIV

Objective

Given the aging of people living with HIV (PLWH) and the high prevalence of HIV-associated neurocognitive disorders, we aimed at describing the clinical, instrumental, and CSF features of PLWH diagnosed with Alzheimer dementia (AD).

Methods

The databases of 3 large Italian outpatient clinics taking care of more than 9,000 PLWH were searched for the diagnosis of AD. After obtaining patients' or their next of kin's consent for publication, anonymous data were collected in an excel spreadsheet and described. Routinely collected CSF biomarkers and radiologic imaging results were recorded whether available.

Results

Four patients were included in this case series who were diagnosed with AD aged between 60 and 74 years. All participants were on highly active antiretroviral therapy and showed nondetectable serum HIV RNA. Memory impairment was the most prominent cognitive feature. The diagnosis was obtained considering the exclusion of other potential causes, MRI and fluorodeoxyglucose-PET features, and, in (in 2/4), CSF AD biomarkers levels. In 1 patient, longitudinal CSF tau/p-tau increased, and beta-amyloid_1-42 decreased over time despite antiretroviral therapy containing nucleotide reverse transcriptase inhibitors.

Conclusions

In older PLWH cognitive symptoms may represent the onset of AD: a multidisciplinary team may be needed for reaching a likely in vivo diagnosis.

Prospective Evaluation of an Abbreviated Test Battery to Screen for Neurocognitive Impairment in HIV-Positive Military Members

Human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) affects around 20-50% of people living with HIV (PLWH). Although batteries of tests are used to identify neurocognitive impairment (NCI), they are long and difficult to perform during a routine clinic visit, thus impairing the ability to diagnose HAND. Therefore, a brief yet sensitive screening tool to identify NCI is necessary. This study prospectively evaluated an abbreviated screening battery with reported 86.5%/87.1% sensitivity/specificity, identified from a planned post-hoc analysis in a prior neurocognitive study among military PLWH. Adult HIV-positive military beneficiaries in the U.S. Military HIV Natural History Study, who agreed to undergo a comprehensive seven-domain neuropsychological battery (16 tests), and who completed an additional 20-min abbreviated battery (AB), comprised of four tests, prior to the full battery (FB) were included in this analysis. A group of 169 individuals completed both tests, of which 25.4% had a positive AB and 17.8% had NCI on FB (global deficit score ≥ 0.5). With the FB as the reference standard, the specificity for the AB was 79.9% (73.2-86.5), however the sensitivity was 50.0% (32.1-67.9). In those with NCI by FB but not AB, the most common impaired domains were executive function (73.3%) and memory (73.3%), both being domains not fully tested by the AB. An abbreviated HAND screening battery of four tests requiring approximately 20 min provided a relatively high level of specificity but lacked sensitivity for detection of NCI. Inclusion of additional domains or alternative scoring approaches may improve sensitivity but require further study. Continued efforts are needed to develop an effective brief screening test for HAND.

Co-receptor signaling in the pathogenesis of neuroHIV

The HIV co-receptors, CCR5 and CXCR4, are necessary for HIV entry into target cells, interacting with the HIV envelope protein, gp120, to initiate several signaling cascades thought to be important to the entry process. Co-receptor signaling may also promote the development of neuroHIV by contributing to both persistent neuroinflammation and indirect neurotoxicity. But despite the critical importance of CXCR4 and CCR5 signaling to HIV pathogenesis, there is only one therapeutic (the CCR5 inhibitor Maraviroc) that targets these receptors. Moreover, our understanding of co-receptor signaling in the specific context of neuroHIV is relatively poor. Research into co-receptor signaling has largely stalled in the past decade, possibly owing to the complexity of the signaling cascades and functions mediated by these receptors. Examining the many signaling pathways triggered by co-receptor activation has been challenging due to the lack of specific molecular tools targeting many of the proteins involved in these pathways and the wide array of model systems used across these experiments. Studies examining the impact of co-receptor signaling on HIV neuropathogenesis often show activation of multiple overlapping pathways by similar stimuli, leading to contradictory data on the effects of co-receptor activation. To address this, we will broadly review HIV infection and neuropathogenesis, examine different co-receptor mediated signaling pathways and functions, then discuss the HIV mediated signaling and the differences between activation induced by HIV and cognate ligands. We will assess the specific effects of co-receptor activation on neuropathogenesis, focusing on neuroinflammation. We will also explore how the use of substances of abuse, which are highly prevalent in people living with HIV, can exacerbate the neuropathogenic effects of co-receptor signaling. Finally, we will discuss the current state of therapeutics targeting co-receptors, highlighting challenges the field has faced and areas in which research into co-receptor signaling would yield the most therapeutic benefit in the context of HIV infection. This discussion will provide a comprehensive overview of what is known and what remains to be explored in regard to co-receptor signaling and HIV infection, and will emphasize the potential value of HIV co-receptors as a target for future therapeutic development.