Elevated rates of mild cognitive impairment in HIV disease

Implications of vascular depression for successful cognitive aging in HIV Disease

Although older adults with HIV are at high risk for mild neurocognitive disorders, a subset experience successful cognitive aging (SCA). HIV is associated with an increased risk of vascular depression (VasDep), which can affect cognitive and daily functioning. The current study examined whether VasDep impedes SCA among older adults with HIV. 136 persons with HIV aged 50 years and older were classified as either SCA+ (n = 37) or SCA- (n = 99) based on a battery of demographically adjusted neurocognitive tests and self-reported cognitive symptoms. Participants were also stratified on the presence of vascular disease (e.g., hypertension) and current depression as determined by the Composite International Diagnostic Interview and the Depression/Dejection scale of the Profile of Mood States. A Cochran-Armitage test revealed a significant additive effect of vascular disease and depression on SCA in this sample of older adults with HIV (z = 4.13, p <.0001). Individuals with VasDep had the lowest frequency of SCA+ (0%), which differed significantly from the group with only vascular disease (30%, OR = 0.04, CI = 0.002,0.68)) and the group with neither vascular disease nor depression (47% OR = 0.02, CI = 0.33,0.001). Findings were not confounded by demographics, HIV disease severity, or other psychiatric and medical factors (ps > 0.05). These data suggest that presence of VasDep may be a barrier to SCA in older adults with HIV disease. Prospective, longitudinal studies with neuroimaging-based operationalizations of VasDep are needed to further clarify this risk factor's role in the maintenance of cognitive and brain health in persons with HIV disease.

The Impact of COVID-19 on People Living with HIV-1 and HIV-1-Associated Neurological Complications

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative pathogen of the coronavirus disease 2019 (COVID-19) pandemic, a fatal respiratory illness. The associated risk factors for COVID-19 are old age and medical comorbidities. In the current combined antiretroviral therapy (cART) era, a significant portion of people living with HIV-1 (PLWH) with controlled viremia is older and with comorbidities, making these people vulnerable to SARS-CoV-2 infection and COVID-19-associated severe outcomes. Additionally, SARS-CoV-2 is neurotropic and causes neurological complications, resulting in a health burden and an adverse impact on PLWH and exacerbating HIV-1-associated neurocognitive disorder (HAND). The impact of SARS-CoV-2 infection and COVID-19 severity on neuroinflammation, the development of HAND and preexisting HAND is poorly explored. In the present review, we compiled the current knowledge of differences and similarities between SARS-CoV-2 and HIV-1, the conditions of the SARS-CoV-2/COVID-19 and HIV-1/AIDS syndemic and their impact on the central nervous system (CNS). Risk factors of COVID-19 on PLWH and neurological manifestations, inflammatory mechanisms leading to the neurological syndrome, the development of HAND, and its influence on preexisting HAND are also discussed. Finally, we have reviewed the challenges of the present syndemic on the world population, with a particular emphasis on PLWH.

The Association Between Objectively-Measured Physical Activity and Cognitive Functioning in Middle-Aged and Older People Living with HIV

Middle-aged and older people living with HIV (PWH) are at higher risk for cognitive impairment and engage in lower levels of physical activity (PA) than seronegative counterparts. Research examining the association between objectively-measured PA and cognitive function in this population is scarce. This cross-sectional study examined the association between accelerometry-measured PA and cognitive functioning among 75 PWH (mean age 55.63). Light PA was the PA variable with the most consistent associations with cognition, with more minutes per week of light PA (performed in bouts of ≥ 10 min) being associated with better executive function, working memory/attention, and speed of processing performance, adjusted for age and current CD4 count. Findings suggest that although middle-aged and older PWH engage in more light than moderate-to-vigorous PA, light PA may be beneficial to cognition. Longitudinal studies are needed to understand PA dose-response associations with cognitive trajectories, cognitive domain specificity of PA effects, and underlying neural mechanisms of PA.

Assessment and Diagnosis of HIV-Associated Dementia

The modern combined antiretroviral treatment (cART) for human immunodeficiency virus (HIV) infection has substantially lowered the incidence of HIV-associated dementia (HAD). The dominant clinical features include deficits in cognitive processing speed, concentration, attention, and memory. As people living with HIV become older, with high rates of comorbidities and concomitant treatments, the prevalence and complexity of cognitive impairment are expected to increase. Currently, the management of HAD and milder forms of HAND is grounded on the best clinical practice, as there is no specific, evidence-based, proven intervention for managing cognitive impairment. The present article acknowledges the multifactorial nature of the cognitive impairments found in HIV patients, outlining the current concepts in the field of HAD. Major areas of interest include neuropsychological testing and neuroimaging to evaluate CNS status, focusing on greater reliability in the exclusion of associated diseases and allowing for earlier diagnosis. Additionally, we considered the evidence for neurological involvement in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and the impact of the coronavirus (COVID-19) pandemic, with wider consequences to population health than can be attributed to the virus itself. The indirect effects of COVID-19, including the increased adoption of telehealth, decreased access to community resources, and social isolation, represent a significant health burden, disproportionately affecting older adults with dementia who have limited social networks and increased functional dependence on the community and health system. This synopsis reviews these aspects in greater detail, identifying key gaps and opportunities for researchers and clinicians; we provide an overview of the current concepts in the field of HAD, with suggestions for diagnosing and managing this important neurological complication, which is intended to be applicable across diverse populations, in line with clinical observations, and closely representative of HIV brain pathology.

Data-Driven vs Consensus Diagnosis of MCI: Enhanced Sensitivity for Detection of Clinical, Biomarker, and Neuropathologic Outcomes

BACKGROUND AND OBJECTIVES

Given prior work demonstrating that mild cognitive impairment (MCI) can be empirically differentiated into meaningful cognitive subtypes, we applied actuarial methods to comprehensive neuropsychological data from the University of California San Diego Alzheimer's Disease Research Center (ADRC) in order to identify cognitive subgroups within ADRC participants without dementia and to examine cognitive, biomarker, and neuropathologic trajectories.

METHODS

Cluster analysis was performed on baseline neuropsychological data (n = 738; mean age 71.8). Survival analysis examined progression to dementia (mean follow-up 5.9 years). CSF Alzheimer disease (AD) biomarker status and neuropathologic findings at follow-up were examined in a subset with available data.

RESULTS

Five clusters were identified: optimal cognitively normal (CN; n = 130) with above-average cognition, typical CN (n = 204) with average cognition, nonamnestic MCI (naMCI; n = 104), amnestic MCI (aMCI; n = 216), and mixed MCI (mMCI; n = 84). Progression to dementia differed across MCI subtypes (mMCI > aMCI > naMCI), with the mMCI group demonstrating the highest rate of CSF biomarker positivity and AD pathology at autopsy. Actuarial methods classified 29.5% more of the sample with MCI and outperformed consensus diagnoses in capturing those who had abnormal biomarkers, progressed to dementia, or had AD pathology at autopsy.

DISCUSSION

We identified subtypes of MCI and CN with differing cognitive profiles, clinical outcomes, CSF AD biomarkers, and neuropathologic findings over more than 10 years of follow-up. Results demonstrate that actuarial methods produce reliable cognitive phenotypes, with data from a subset suggesting unique biological and neuropathologic signatures. Findings indicate that data-driven algorithms enhance diagnostic sensitivity relative to consensus diagnosis for identifying older adults at risk for cognitive decline.

Pressing Questions and Challenges in the HIV-1 and SARS-CoV-2 Syndemic

Since emerging into the human population in late 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has reached across the globe to infect >80 million people. The coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 can range in severity from mild and asymptomatic to severe and fatal. Identifying risk factors for adverse outcomes in COVID-19 is a major challenge. In the context of the existing HIV-1 pandemic, whether COVID-19 disproportionately burdens people living with HIV-1 infection (PLWH) is unclear. The following discussion highlights pressing questions and challenges in the HIV-1 and SARS-CoV-2 syndemic, including (i) age, sex, and race as drivers of COVID-19 severity; (ii) whether chronic inflammation common in PLWH influences immune response; (iii) whether disease severity and trajectory models for COVID-19 ought to be calibrated for PLWH; (iv) vaccine considerations, and finally, (v) long-term health outcomes in PLWH that are further burdened by coinfection with SARS-CoV-2.

Association of HIV infection and cognitive impairment in older adults: A meta-analysis

OBJECTIVE

To synthesize evidence on the association between human immunodeficiency virus (HIV) infection and cognitive impairment in older adults.

DESIGN

Meta-analysis.

PARTICIPANTS

Adults aged 50 years or older.

METHODS

In this systematic literature review and meta-analysis, we searched PubMed, Scopus, Embase, and APA/PsycNet for studies published before July 21, 2020, that assessed the association between HIV-infection and cognitive impairment. We calculated pooled odds ratios (ORs) of cognitive impairment for people living with HIV (PLWH) and 95 % confidence intervals (CIs) using random-effect models and calculated pooled mean difference (MD) for major cognitive domains between PLWH and HIV-uninfected adults. We assessed risk of bias using the Newcastle-Ottawa scale.

RESULTS

Of the 4432 studies identified, 21 cross-sectional studies were eligible for the meta-analysis, including 15 examining global cognitive impairment. The meta-analysis showed that older PLWH were more likely to be cognitively impaired than HIV-uninfected controls (OR = 2.44, 95 % CI = [1.69, 3.53], number of estimates (k) = 15, I2 = 71 %). This higher likelihood was shown in studies from high income countries (OR = 2.63, 95 % CI = [1.76, 3.94], k = 12, I2 = 55 %), but not from upper-middle income countries (OR = 1.96, 95 % CI = [0.26, 14.68], k = 3, I2 = 91 %). PLWH had lower scores than HIV-uninfected adults in 5 out of 7 major cognitive domains, including executive function (MD = -0.42, 95 % CI = [-0.72, -0.11], k = 5, I2 = 32 %), processing speed (MD = -0.33, 95 % CI = [-0.59, -0.08], k = 6, I2 = 16 %), verbal (MD=-0.29, 95 % CI = [-0.48, -0.10], k = 6, I2 = 0%), recall (MD = -0.24, 95 % CI = [-0.38, -0.10], k = 6, I2 = 0%) and motor/psychomotor (MD = -0.38, 95 % CI = [-0.59, -0.16], k = 5, I2 = 31 %) performance.

CONCLUSIONS/IMPLICATIONS

Our meta-analysis provides empirical evidence that HIV infection is associated with an increased risk of cognitive impairment among older adults, especially in cognitive domains of executive function, processing speed, verbal, recall, and motor/psychomotor.

Higher CSF Ferritin Heavy-Chain (Fth1) and Transferrin Predict Better Neurocognitive Performance in People with HIV

HIV-associated neurocognitive disorder (HAND) remains prevalent despite antiretroviral therapy and involves white matter damage in the brain. Although iron is essential for myelination and myelin maintenance/repair, its role in HAND is largely unexplored. We tested the hypotheses that cerebrospinal fluid (CSF) heavy-chain ferritin (Fth1) and transferrin, proteins integral to iron delivery and myelination, are associated with neurocognitive performance in people with HIV (PWH). Fth1, transferrin, and the pro-inflammatory cytokines TNF-α and IL-6 were quantified in CSF at baseline (entry) in 403 PWH from a prospective observational study who underwent serial, comprehensive neurocognitive assessments. Associations of Fth1 and transferrin with Global Deficit Score (GDS)-defined neurocognitive performance at baseline and 30-42 months of follow-up were evaluated by multivariable regression. While not associated with neurocognitive performance at baseline, higher baseline CSF Fth1 predicted significantly better neurocognitive performance over 30 months in all PWH (p < 0.05), in PWH aged < 50 at 30, 36, and 42 months (all p < 0.05), and in virally suppressed PWH at all three visit time-points (all p < 0.01). Higher CSF transferrin was associated with superior neurocognitive performance at all visits, primarily in viremic individuals (all p < 0.05). All associations persisted after adjustment for neuro-inflammation. In summary, higher CSF Fth1 is neuroprotective over prolonged follow-up in all and virally suppressed PWH, while higher CSF transferrin may be most neuroprotective during viremia. We speculate that higher CSF levels of these critical iron-delivery proteins support improved myelination and consequently, neurocognitive performance in PWH, providing a rationale for investigating their role in interventions to prevent and/or treat HAND.

Characterization of HIV-Associated Neurocognitive Impairment in Middle-Aged and Older Persons With HIV in Lima, Peru

Background: With widespread use of antiretroviral medications, people living with HIV (PWH) are living longer worldwide, increasing their risk of developing neurocognitive impairment (NCI). The proportion of Peruvians over age 60 is expected to increase to 25% of the population by 2050, including PWH. Therefore, the problem of aging and NCI, especially in the setting of HIV infection, is uniquely pressing. We sought to study the rates of and risk factors associated with NCI among middle-aged and older PWH in Lima, Peru. Materials and Methods: Sociodemographic, medical (infectious and non-infectious), and psychiatric comorbidity and laboratory data were collected. We administered a brief neuropsychological battery evaluating seven cognitive domains affected in HIV-associated NCI and a depression screening. Cognitive test raw scores were converted to T-scores that were demographically adjusted. Descriptive statistics were performed together with regression (unadjusted and adjusted) analyses to determine potential risk factors for NCI among PWH. Results: This was a cross-sectional study in which 144 PWH aged ≥40 years attending a large HIV clinic in Lima, Peru, were recruited from September 2019 to March 2020. Mean age was 51.6 ± 7.7 years, and mean years of education were 14.0 ± 3.1 with 15% females. Median [interquartile range (IQR)] current CD4 and nadir CD4 were 554 (371, 723) and 179 (83, 291), respectively, and 10% currently had AIDS. The prevalence of NCI was 28.5%, and many demonstrated difficulty with attention and working memory (70%). One-quarter of PWH had mild depression or worse on Patient Health Questionnaire 9 (PHQ-9 ≥ 5). In bivariate analyses, neither a depression history nor a higher PHQ-9 score correlated with NCI. No other non-communicable medical or psychiatric comorbidity nor HIV characteristic was predictive of NCI. Having a positive lifetime history of hepatitis B infection, pulmonary tuberculosis, or syphilis increased risk of NCI (PR 1.72; 95% CI 1.04-2.86) in unadjusted analyses, but not in adjusted analyses. Conclusions: NCI among older Peruvians with HIV was found to be highly prevalent with levels consistent with prior reports of HIV-associated NCI worldwide. Common latent HIV-associated co-infections, including latent syphilis, hepatitis B infection, or pulmonary tuberculosis, may increase the risk of NCI among middle-aged and older PWH in Peru.

The Intersection of Cognitive Ability and HIV: A Review of the State of the Nursing Science

ABSTRACT

Neurocognitive problems have been endemic to the HIV epidemic since its beginning. Four decades later, these problems persist, but currently, they are attributed to HIV-induced inflammation, the long-term effects of combination antiretroviral therapy, lifestyle (i.e., physical activity, drug use), psychiatric, and age-associated comorbidities (i.e., heart disease, hypertension). In many cases, persons living with HIV (PLWH) may develop cognitive problems as a function of accelerated or accentuated normal aging and lifestyle rather than HIV itself. Nonetheless, such cognitive impairments can interfere with HIV care, including medication adherence and attending clinic appointments. With more than half of PLWH 50 years and older, and 30%-50% of all PLWH meeting the criteria for HIV-associated neurocognitive disorder, those aging with HIV may be more vulnerable to developing cognitive problems. This state of the science article provides an overview of current issues and provides implications for practice, policy, and research to promote successful cognitive functioning in PLWH.

Iron-regulatory genes are associated with Neuroimaging measures in HIV infection

The pathogenesis of HIV-associated neurocognitive impairment (NCI) may involve iron dysregulation. In 243 HIV-seropositive adults without severe comorbidities, we therefore genotyped 250 variants in 20 iron-related genes and evaluated their associations with magnetic resonance imaging measures of brain structure and metabolites, including measures previously linked to NCI. Multivariable regression analyses examined associations between genetic variants and neuroimaging measures, adjusting for relevant covariates and multiple testing. Exploratory analyses stratified by NCI (Global Deficit Score ≥ 0.5 vs. <0.5), virus detectability in plasma, and comorbidity levels were also performed. Of 27 variants (in 12 iron-regulatory genes) associated with neuroimaging measures after correction for the 37 haplotype blocks represented, 3 variants survived additional correction for the 21 neuroimaging measures evaluated and demonstrated biologically plausible associations. SLC11A1 rs7576974_T was significantly associated with higher frontal gray matter N-acetylaspartate (p = 3.62e^-5). Among individuals with detectable plasma virus, TFRC rs17091382_A was associated with smaller subcortical gray matter volume (p = 3.23e^-5), and CP rs4974389_A (p = 3.52e^-5) was associated with higher basal ganglia Choline in persons with mild comorbidities. Two other strong associations were observed for variants in SLC40A1 and ACO2 but were not robust due to low minor-allele frequencies in the study sample. Variants in iron metabolism and transport genes are associated with structural and metabolite neuroimaging measures in HIV-seropositive adults, regardless of virus suppression on antiretroviral therapy. These variants may confer susceptibility to HIV-related brain injury and NCI. Further studies are needed to determine the specificity of these findings to HIV infection and explore potential underlying mechanisms.

Distinguishing Amnestic Mild Cognitive Impairment From HIV-Associated Neurocognitive Disorders

BACKGROUND

Memory impairment occurs in human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) and amnestic mild cognitive impairment (aMCI), the precursor to Alzheimer disease (AD). Methods are needed to distinguish aMCI-associated from HAND-associated impairment in people with HIV (PWH). We developed a neuropsychological method of identifying aMCI in PWH and tested this by relating AD neuropathology (β-amyloid, phospho-Tau) to aMCI versus HAND classification.

METHODS

Seventy-four HIV-positive cases (aged 50-68 years) from the National NeuroAIDS Tissue Consortium had neurocognitive data within 1 year of death and data on β-amyloid and phospho-Tau pathology in frontal brain tissue. High aMCI risk was defined as impairment (<1.0 SD below normative mean) on 2 of 4 delayed recall or recognition outcomes from a verbal and nonverbal memory test (at least 1 recognition impairment required). Differences in β-amyloid and phospho-Tau by aMCI and HAND classification were examined.

RESULTS

High aMCI risk was more common in HAND (69.0%) versus no HAND (37.5%) group. β-amyloid pathology was 4.75 times more likely in high versus low aMCI risk group. Phospho-Tau pathology did not differ between aMCI groups. Neither neuropathological feature differed by HAND status.

CONCLUSIONS

Amnestic mild cognitive impairment criteria that include recognition impairment may help to detect AD-like cognitive/biomarker profiles among PWH.

Cognitive and motor deficits in older adults with HIV infection: Comparison with normal ageing and Parkinson's disease

Despite the life-extending success of antiretroviral pharmacotherapy in HIV infection (HIV), the prevalence of mild cognitive impairment in HIV remains high. Near-normal life expectancy invokes an emerging role for age-infection interaction and a potential synergy between immunosenescence and HIV-related health factors, increasing risk of cognitive and motor impairment associated with degradation in corticostriatal circuits. These neural systems are also compromised in Parkinson's disease (PD), which could help model the cognitive deficit pattern in HIV. This cross-sectional study examined three groups, age 45-79 years: 42 HIV, 41 PD, and 37 control (CTRL) participants, tested at Stanford University Medical School and SRI International. Neuropsychological tests assessed executive function (EF), information processing speed (IPS), episodic memory (MEM), visuospatial processing (VSP), and upper motor (MOT) speed and dexterity. The HIV and PD deficit profiles were similar for EF, MEM, and VSP. Although only the PD group was impaired on MOT compared with CTRL, MOT scores were related to cognitive scores in HIV but not PD. Performance was not related to depressive symptoms, socioeconomic status, or CD4⁺ T-cell counts. The overlap of HIV-PD cognitive deficits implicates frontostriatal disruption in both conditions. The motor-cognitive score relation in HIV provides further support for the hypothesis that these processes share similar underlying mechanisms in HIV infection possibly expressed with or exacerbated by ageing.

Is HIV disease associated with a discrepancy between premorbid verbal IQ and neurocognitive functions?

Introduction: There is debate about the optimal approach to diagnose neurocognitive impairment in people with HIV disease. The current "gold-standard" uses normative data to determine whether performance is below that of demographically comparable peers. This study investigated the utility of a discrepancy analysis approach, which compares normative neurocognitive performance directly to estimated premorbid intellectual functioning. Method: A total of 570 adults with and without HIV disease completed a comprehensive neurocognitive battery and the Wechsler Test of Adult Reading (WTAR), an oral word reading measure that was used to estimate premorbid verbal IQ. Normative scores for six neurocognitive domains were subtracted from the WTAR standardized score to calculate discrepancy scores where higher scores indicated greater discrepancies. Results: In models adjusting for relevant confounds, an interaction between HIV serostatus and domain discrepancy scores emerged such that persons with HIV had significantly higher discrepancy scores than seronegative participants, specifically in the domains of attention and episodic memory. Of clinical relevance, persons with HIV were two to three times more likely than their seronegative counterparts to have clinically discordant performance relative to premorbid verbal IQ in these domains. Additionally, the standard normative approach and discrepancy analysis method had fair to moderate agreement for classifying attention and episodic memory impairment in the participants with HIV disease. Conclusions: HIV disease is associated with discrepancies between premorbid IQ estimates and the domains of attention and memory, consideration of which may be a clinically useful complement to standard normative approaches to diagnosing HIV-associated neurocognitive disorders.

Harvard HIV and Aging Workshop: Perspectives and Priorities from Claude D. Pepper Centers and Centers for AIDS Research

People aging with HIV (PAWH) infection experience greater impairments in physical and cognitive function, in addition to higher rates of peripheral comorbid conditions (e.g., renal failure, diabetes, bone fracture, hypertension, cardiovascular disease, polypharmacy, and multimorbidity). While multifactorial drivers, including HIV infection itself, antiretroviral therapy-related toxicities, disparities in care, and biobehavioral factors, likely contribute, there remains an overarching question as to what are the relevant age-related mechanisms and models that could inform interventions that promote health span and life span in PAWH? This workshop was convened to hear from experts on the biology of aging and HIV researchers studying PAWH to focus on advancing investigations at the interface of HIV and Aging. In this study, we summarize the discussions from the Harvard Center for AIDS Research and Boston Claude D. Pepper cosponsored workshop on HIV and Aging, which took place in October 2018.

HIV-1 infection alters energy metabolism in the brain: Contributions to HIV-associated neurocognitive disorders

The brain is particularly sensitive to changes in energy supply. Defects in glucose utilization and mitochondrial dysfunction are hallmarks of nearly all neurodegenerative diseases and are also associated with the cognitive decline that occurs as the brain ages. Chronic neuroinflammation driven by glial activation is commonly implicated as a contributing factor to neurodegeneration and cognitive impairment. Human immunodeficiency virus-1 (HIV-1) disrupts normal brain homeostasis and leads to a spectrum of HIV-associated neurocognitive disorders (HAND). HIV-1 activates stress responses in the brain and triggers a state of chronic neuroinflammation. Growing evidence suggests that inflammatory processes and bioenergetics are interconnected in the propagation of neuronal dysfunction. Clinical studies of people living with HIV and basic research support the notion that HIV-1 creates an environment in the CNS that interrupts normal metabolic processes at the cellular level to collectively alter whole brain metabolism. In this review, we highlight reports of abnormal brain metabolism from clinical studies and animal models of HIV-1. We also describe diverse CNS cell-specific changes in bioenergetics associated with HIV-1. Moreover, we propose that attention should be given to adjunctive therapies that combat sources of metabolic dysfunction as a mean to improve and/or prevent neurocognitive impairments.

Neuropsychological and Syntactic Deficits in HIV Seropositive Males

Objective:

Given the underlying frontal-basal ganglia circuit neuropathogenesis of HIV-infected individuals, it is surprising that little is reported about potential language deficits as part of their higher cognitive dysfunctional profile. This study aims to elucidate whether HIV-positive individuals have linguistic impairments that may originate from or be intensified by deficits in cognitive functions. The research questions address (i) quantitative differences in sentence repetition abilities involving complex syntactic phenomena between adults with HIV and non-HIV healthy controls (ii) correlations of sentence repetition scores with neurocognitive measures and (iii) correlation of sentence repetition performance with duration and severity of HIV.

Methods:

A battery of neuropsychological tests were administered to 40 HIV - seropositive males and 40 demographically matched healthy controls to assess verbal learning/episodic memory, psychomotor speed, executive functions and visuospatial abilities. Language abilities were evaluated using a repetition task that screened specific complex syntactic operations at the sentence-level.

Results:

A significant difference was noted between the two groups regarding correct repetition of the sentence repetition task with the control group outperforming the HIV-seropositive group. For the HIV group, significant correlations were found for correct sentence repetition with years of education, duration of illness, Mini-Mental State Examination, semantic and phonemic fluency, symbol digit modality test scores, and the Trail Making Test (parts A and B).

Conclusion:

Speech-language pathologists and neuropsychologists should screen for language deficits associated with the different clinical syndromes in HIV patients as part of their routine clinical care.

Current Challenges and Solutions in Research and Clinical Care of Older Persons Living with HIV: Findings Presented at the 9th International Workshop on HIV and Aging

In the era of effective antiretroviral therapy, the number of older people with HIV (PWH) is increasing, and those aging with HIV are experiencing an increasing burden of age-associated comorbidities. Life expectancy among older PWH is approaching that of demographically comparable HIV-uninfected (HIV-) adults. With this changing demographic of PWH come new challenges for researchers and clinicians in how to identify, address, and manage the complex interplay of treated HIV infection and aging-associated factors. In response to these challenges, the annual International Workshop on HIV and Aging was initiated in 2009 as a multidisciplinary platform for scientific discourse on the research and clinical complications arising from the aging population of PWH. The multidisciplinary nature of the workshop has resulted in a wide range of topics addressed over the past 9 years, from basic mechanisms in aging and HIV pathogenesis, to epidemiology of aging within large cohorts, interventions, and implementation of clinical programs. Herein, we summarize the key topics discussed at the 9th Annual International Workshop on HIV and Aging 2018, including "inflammaging," mitochondrial dysfunction, exercise interventions, HIV-associated neurocognitive impairment, metabolic dysfunction, menopause, and polypharmacy. In addition to recent developments in research and clinical care, we discuss open questions and future research directions required to better understand the interaction of HIV and aging.

Prospective memory partially mediates the association between aging and everyday functioning

Objective: Older adults commonly experience declines in everyday functioning, the reasons for which are multifactorial. Prospective memory (PM), or remembering to carry out intended actions, can be an executively demanding cognitive process that declines with older age and is independently associated with a variety of everyday functions (e.g. taking medication). This study examined the hypothesis that PM mediates the relationship between older age and poorer everyday functioning.Method: A total of 468 community-dwelling adults (ages 18-75) with a range of medical comorbidities (e.g. viral infection) were classified as dependent on four well-validated measures of manifest everyday functioning: activities of daily living, employment status, the Karnofsky Scale of Performance Status, and self-reported cognitive symptoms. Participants completed the Memory for Intentions Test (MIsT) to measure PM, alongside clinical tests of executive functions and retrospective memory.Results: Controlling for education and comorbidities, bootstrap analysis revealed a significant direct effect of age on everyday functioning and a significant mediated effect of age on everyday functioning through the indirect effect of time-based b = .006 [.003, .010] and event-based PM (b = .005, [.002, .009]), as well as slightly smaller effects for executive functions (b = .003, [.001, .005]) and retrospective memory (b = .002, [.001, .005]).Conclusions: These cross-sectional data suggest that executively demanding aspects of declarative memory play an important partial mediating role between an individual factor (i.e. age) and daily life activities, and highlight the possible benefit of targeting PM for improving everyday functioning in older adults.

Longitudinal trajectories of neurocognitive test performance among individuals with perinatal HIV-infection and -exposure: adolescence through young adulthood

There are an estimated 2.1 million youth less than 15 years of age living with HIV globally (the majority perinatally HIV-infected [PHIV]) and millions more perinatally HIV-exposed uninfected (PHEU) youth who are expected to survive through adolescence and into adulthood. Transitioning from adolescence to young adulthood requires adaptation to more demanding social interactions, academic pressures, and individual responsibilities which place distinct demands on neurocognitive functions. This study examined longitudinal trajectories of neurocognitive test performance in the domains of processing speed (PS), working memory (WM), and executive functioning (EF) among PHIV and demographically similar PHEU from adolescence through young adulthood. Data for this paper come from four time points, spanning approximately 10 years, within the Child and Adolescent Self-Awareness and Health Study (CASAH). Youth age ranged from 15 to 29 years. Longitudinal linear mixed effect models were computed for each test. Few differences in performance were found on tests of EF and WM between PHIV and PHEU youth as they aged, though PHEU youth showed significantly better PS as they aged than PHIV youth. Future research is needed to understand these vulnerable youth's neurocognitive trajectories as a function of HIV infection and -exposure, biological functions and psychosocial stressors.

Perceived discrimination and cognitive function in middle-aged and older adults living with HIV in China

Middle-aged and older adults with HIV experience double discrimination and cognitive impairment due to both their HIV status and their age. However, the relationship between perceived discrimination and self-reported cognitive ability in middle-aged and older people living with HIV (PLWH) is less clear. We measured self-reported perceived discrimination and cognitive ability using the Expanded Everyday Discrimination Scale and the subscale of the AIDS Health Assessment Questionnaire (AIDS-HAQ). The study sample included 324 middle-aged and older PLWH (over 45 years old) from five designated HIV hospitals in three regions (east coast, middle, and southwest regions) of China. The descriptive analysis showed that 45.37% of the participants reported perceiving discrimination at least once in the past twelve months, and 47.22% reported having at least one type of cognitive impairment. Multiple linear regression results showed that higher levels of perceived discrimination (β = -0.121, P = 0.036) were significantly associated with lower levels of self-reported cognitive ability after controlling for several covariates, including sociodemographic variables, mental health status, health behaviors, and social support. A longer duration of HIV was also related to a lower level of self-reported cognitive ability. Our findings indicate that perceived discrimination is related to self-reported cognitive ability and suggest that counseling services and support systems should be developed to reduce age- and disease-associated discrimination. A reduction in perceived discrimination would improve not only overall wellbeing but also cognitive ability in later life.

Aging, comorbidities, and the importance of finding biomarkers for HIV-associated neurocognitive disorders

HIV-associated neurocognitive disorders (HAND) continue to affect a large proportion of persons living with HIV despite effective viral suppression with combined antiretroviral therapy (cART). Importantly, milder versions of HAND have become more prevalent. The pathogenesis of HAND in the era of cART appears to be multifactorial with contributions from central nervous system (CNS) damage that occur prior to starting cART, chronic immune activation, cART neurotoxicity, and various age-related comorbidities (i.e., cardiovascular and cerebrovascular disease, diabetes, hyperlipidemia). Individuals with HIV may experience premature aging, which could also contribute to cognitive impairment. Likewise, degenerative disorders aside from HAND increase with age and there is evidence of shared pathology between HAND and other neurodegenerative diseases, such as Alzheimer's disease, which can occur with or without co-existing HAND. Given the aforementioned complex interactions associated with HIV, cognitive impairment, and aging, it is important to consider an age-appropriate differential diagnosis for HAND as the HIV-positive population continues to grow older. These factors make the accuracy and reliability of the diagnosis of mild forms of HAND in an aging population of HIV-infected individuals challenging. The complexity of current diagnosis of mild HAND also highlights the need to develop reliable biomarkers. Ultimately, the identification of a set of specific biomarkers will be required to achieve early and accurate diagnosis, which will be necessary assuming specific treatments for HAND are developed.

HIV-associated neurodegeneration: exploitation of the neuronal cytoskeleton

Human immunodeficiency virus-1 (HIV) infection of the central nervous system damages synapses and promotes axonal injury, ultimately resulting in HIV-associated neurocognitive disorders (HAND). The mechanisms through which HIV causes damage to neurons are still under investigation. The cytoskeleton and associated proteins are fundamental for axonal and dendritic integrity. In this article, we review evidence that HIV proteins, such as the envelope protein gp120 and transactivator of transcription (Tat), impair the structure and function of the neuronal cytoskeleton. Investigation into the effects of viral proteins on the neuronal cytoskeleton may provide a better understanding of HIV neurotoxicity and suggest new avenues for additional therapies.

Frequency and Correlates of Subjective Cognitive Impairment in HIV Disease

The increasing prevalence of older adults living with HIV has raised growing concerns about a possible rise in the incidence of neurocognitive disorders due to HIV and other age-related factors. In typical aging, subjective cognitive impairment (SCI) among individuals with normal neurocognitive functioning may be an early manifestation of an incipient neurocognitive disorder. The current study examined the frequency and correlates of SCI in 188 HIV-infected adults without performance-based neurocognitive deficits or a current psychiatric disorder and 133 HIV seronegative comparison participants. All participants completed the Prospective and Retrospective Memory Questionnaire and Profile of Mood States Confusion/Bewilderment scale. Consistent with the diagnostic criteria proposed by Jessen et al. (Alzheimers Dement 10(6):844-852, 2014), participants were classified with SCI if their scores on either of the self-reported measures was greater than 1.5 SD above the normative mean. A logistic regression controlling for current mood complaints and lifetime history of substance use disorders revealed that HIV infection increased the odds of SCI (odds ratio= 4.5 [1.6, 15.4], p = 0.004). Among HIV+ individuals, SCI was associated with lower performance-based learning and delayed memory scores (Cohen's d range 0.41-0.42.) and poorer global everyday functioning (odds ratio= 8.5 [2.6, 15.9]), but not HIV disease severity (ps > 0.10). In a sample of individuals without neurocognitive impairment or elevated mood symptoms, HIV disease was associated with a nearly fivefold increased odds of SCI compared to seronegative individuals, which may indicate an increased risk for developing major neurocognitive disorders as these HIV+ individuals age.

Abnormal Cerebral Perfusion Profile in Older Adults with HIV-Associated Neurocognitive Disorder: Discriminative Power of Arterial Spin-Labeling

BACKGROUND AND PURPOSE

The aging HIV-infected (HIV⁺) population has increased vascular comorbidities, including stroke, and increased cognitive deficits compared with the general population. Arterial spin-labeling is a technique to measure cerebral blood flow and is more sensitive than regional volume loss in assessing neurodegenerative diseases and cognitive aging. Previous studies have found global cerebral perfusion abnormalities in the HIV⁺ participants. In this study, we evaluated the specific regional pattern of CBF abnormalities in older HIV⁺ participants using quantitative whole-brain arterial spin-labeling.

MATERIALS AND METHODS

CBF data from the UCSF HIV Over 60 Cohort and the Alzheimer Disease Neuroimaging Initiative were retrospectively evaluated to identify 19 HIV⁺ older adults, all with plasma viral suppression (including 5 with HIV-associated neurocognitive disorder); 13 healthy, age-matched controls; and 19 participants with early mild cognitive impairment. CBF values were averaged by ROI and compared among the 3 groups using generalized linear models.

RESULTS

When we accounted for age, education, sex, and vascular risk factors, the HIV⁺ participants demonstrated alterations in regional cerebral perfusion, including hypoperfusion of bilateral temporal, parietal, and occipital brain regions compared with both clinically healthy participants and those with mild cognitive impairment. Arterial spin-labeling showed reasonable test characteristics in distinguishing those with HIV-associated neurocognitive disorder from healthy controls and participants with mild cognitive impairment.

CONCLUSIONS

This study found specific CBF patterns associated with HIV status despite viral suppression-data that should animate further investigations into the pathobiologic basis of vascular and cognitive abnormalities in HIV-associated neurocognitive disorders.

The effects of aging and HIV disease on employment status and functioning

OBJECTIVE

As the prevalence of older adults living with HIV disease increases, questions are emerging regarding the extent to which older age amplifies the adverse effects of HIV on employment status and functioning. This cross-sectional study sought to (1) investigate the combined effects of HIV and older age on employment status, (2) identify clinicodemographic correlates of employment status among older HIV+ persons, and (3) examine the combined effects of HIV and age on workplace performance among employed participants.

METHOD

The sample was 358 HIV+ (163 older, 195 younger) and 193 HIV- (94 older, 99 younger) adults, who completed a comprehensive neurocognitive research assessment that included measures of employment status and current workplace functioning.

RESULTS

We observed main effects of HIV and age on employment status, but no interaction. The older HIV+ sample demonstrated particularly high rates of disability, rather than elective retirement or unemployment. Among older HIV+ adults significant predictors of employment status included age, global neurocognitive functioning, combination antiretroviral therapy status, age at HIV infection, and hepatitis C coinfection. Finally, self-reported work functioning of older HIV+ adults differed only from the younger HIV- group.

CONCLUSION

Findings suggest that older age and HIV disease have additive adverse effects on employment status, but not work functioning, and that employment status is associated with both neurocognitive and medical risk factors among older HIV+ adults. Further longitudinal research is needed to elucidate specific disease and demographic characteristics that may operate as protective factors for retaining gainful employment among older HIV+ adults. (PsycINFO Database Record

Persistent EcoHIV infection induces nigral degeneration in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-intoxicated mice

The widespread use of antiretroviral therapy for treatment of human immunodeficiency virus (HIV) infections has dramatically improved the quality and duration of life for HIV-positive individuals. Despite this success, HIV persists for the life of an infected person in tissue reservoirs including the nervous system. Thus, whether HIV exacerbates age-related brain disorders such as Parkinson's disease (PD) is of concern. In support of this idea, HIV infection can be associated with motor and gait abnormalities that parallel late-stage manifestations of PD including dopaminergic neuronal loss. With these findings in hand, we investigated whether viral infection could affect nigrostriatal degeneration or exacerbate chemically induced nigral degeneration. We now demonstrate an additive effect of EcoHIV on dopaminergic neuronal loss and neuroinflammation induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine intoxication. HIV-1-infected humanized mice failed to recapitulate these EcoHIV results suggesting species-specific neural signaling. The results demonstrate a previously undefined EcoHIV-associated neurodegenerative response that may be used to model pathobiological aspects of PD.

Disability Among Middle-Aged and Older Persons With Human Immunodeficiency Virus Infection

Background

Older human immunodeficiency virus (HIV)-infected adults may experience higher rates of frailty and disability than the general population. Improved understanding of the prevalence, risk factors, and types of impairment can better inform providers and the healthcare system.

Methods

HIV-infected participants within the AIDS Clinical Trials Group A5322 HAILO study self-reported disability by the Lawton-Brody Instrumental Activities of Daily Living (IADL) Questionnaire. Frailty was measured by 4-m walk time, grip strength, self-reported weight loss, exhaustion, and low activity. Logistic regression models identified characteristics associated with any IADL impairment. Agreement between IADL impairment and frailty was assessed using the weighted kappa statistic.

Results

Of 1015 participants, the median age was 51 years, 15% were aged ≥60 years, 19% were female, 29% black, and 20% Hispanic. At least 1 IADL impairment was reported in 18% of participants, most commonly with housekeeping (48%) and transportation (36%) and least commonly with medication management (5%). In multivariable models, greater disability was significantly associated with neurocognitive impairment, lower education, Medicare/Medicaid insurance (vs private/other coverage), smoking, and low physical activity. Although a greater proportion of frail participants had IADL impairment (52%) compared to non-frail (11%) persons, agreement was poor (weighted kappa <0.18, 95% confidence interval, 0.13, 0.23).

Conclusion

IADL disability occurs frequently among middle-aged and older HIV-infected adults on effective antiretroviral therapy. Potentially modifiable risk factors (smoking, physical activity) provide targets for interventions to maintain independent living. Systematic recognition of persons at greater risk for disability can facilitate connection to resources that may help preserve independence.

The Aging Brain With HIV Infection: Effects of Alcoholism or Hepatitis C Comorbidity

As successfully treated individuals with Human Immunodeficiency Virus (HIV)-infected age, cognitive and health challenges of normal aging ensue, burdened by HIV, treatment side effects, and high prevalence comorbidities, notably, Alcohol Use Disorders (AUD) and Hepatitis C virus (HCV) infection. In 2013, people over 55 years old accounted for 26% of the estimated number of people living with HIV (~1.2 million). The aging brain is increasingly vulnerable to endogenous and exogenous insult which, coupled with HIV infection and comorbid risk factors, can lead to additive or synergistic effects on cognitive and motor function. This paper reviews the literature on neuropsychological and in vivo Magnetic Resonance Imaging (MRI) evaluation of the aging HIV brain, while also considering the effects of comorbidity for AUD and HCV.

Effect of age and level of education on neurocognitive impairment in HIV positive Zambian adults

OBJECTIVE

Older age and lower education levels are known to be associated with worse neurocognitive (NC) performance in healthy adults, and individuals with HIV infection may experience accelerated brain/cognition aging. However, higher education may possibly protect against HIV-associated neurocognitive disorders (HAND). The aim of the current cross-sectional study was to assess the effect of age and education in an HIV-1 clade C infected adult population in urban Zambia.

METHOD

Demographically corrected Zambian norms on a neuropsychological (NP) test battery were used to correct for normal age and education effects. The study assessed 286 HIV positive (+) males (37.1%) and females (62.9%) with a mean age of 41.35 (SD = 8.56) and mean years of education = 10.16 (SD = 2.18). A comprehensive NP test battery was used to assess cognitive domains frequently affected by HIV: attention/working memory, learning/and delayed recall, executive function, verbal fluency, processing speed, verbal and visual episodic memory, and fine motor skills.

RESULTS

In younger HIV+ Zambians, higher education evidenced protective effects against NC impairments overall, and for the specific domains of executive functions, learning and speed of information processing. Impairment scores did not support accelerated overall brain aging although the restricted age range and relative youth of our total sample may have precluded detection of such tendencies.

CONCLUSIONS

The present study raises the need to investigate factors that could be implicated in the poor neurocognitive performance among the younger, less educated HIV+ individuals in Zambia. (PsycINFO Database Record

Differentiating HIV-Associated Neurocognitive Disorders From Alzheimer's Disease: an Emerging Issue in Geriatric NeuroHIV

PURPOSE OF REVIEW

The purpose of this review was to examine characteristics that may distinguish HIV-associated neurocognitive disorder (HAND) from early Alzheimer's disease (AD).

RECENT FINDINGS

Cerebrospinal fluid (CSF) AD biomarkers are perturbed in HIV, yet these alterations may be limited to settings of advanced dementia or unsuppressed plasma HIV RNA. Neuropsychological testing will require extensive batteries to maximize utility. Structural imaging is limited for early AD detection in the setting of HIV, but proper studies are absent. While positron-emission tomography (PET) amyloid imaging has altered the landscape of differential diagnosis for age-associated neurodegenerative disorders, costs are prohibitive. Risk for delayed AD diagnosis in the aging HIV-infected population is now among the most pressing issues in geriatric neuroHIV. While clinical, imaging, and biomarker characterizations of AD are extensively defined, fewer data define characteristics of HIV-associated neurocognitive disorder in the setting of suppressed plasma HIV RNA. Data needed to inform the phenotype of AD in the setting of HIV are equally few.

Aged Chinese-origin rhesus macaques infected with SIV develop marked viremia in absence of clinical disease, inflammation or cognitive impairment

BACKGROUND

Damage to the central nervous system during HIV infection can lead to variable neurobehavioral dysfunction termed HIV-associated neurocognitive disorders (HAND). There is no clear consensus regarding the neuropathological or cellular basis of HAND. We sought to study the potential contribution of aging to the pathogenesis of HAND. Aged (range = 14.7-24.8 year) rhesus macaques of Chinese origin (RM-Ch) (n = 23) were trained to perform cognitive tasks. Macaques were then divided into four groups to assess the impact of SIVmac251 infection (n = 12) and combined antiretroviral therapy (CART) (5 infected; 5 mock-infected) on the execution of these tasks.

RESULTS

Aged SIV-infected RM-Ch demonstrated significant plasma viremia and modest CSF viral loads but showed few clinical signs, no elevations of systemic temperature, and no changes in activity levels, platelet counts or weight. Concentrations of biomarkers of acute and chronic inflammation such as soluble CD14, CXCL10, IL-6 and TNF-α are known to be elevated following SIV infection of young adult macaques of several species, but concentrations of these biomarkers did not shift after SIV infection in aged RM-Ch and remained similar to mock-infected macaques. Neither acute nor chronic SIV infection or CART had a significant impact on accuracy, speed or percent completion in a sensorimotor test.

CONCLUSIONS

Viremia in the absence of a chronic elevated inflammatory response seen in some aged RM-Ch is reminiscent of SIV infection in natural disease resistant hosts. The absence of cognitive impairment during SIV infection in aged RM-Ch might be in part attributed to diminishment of some facets of the immunological response. Additional study encompassing species and age differences is necessary to substantiate this hypothesis.

Effects of HIV-1 Tat and Methamphetamine on Blood-Brain Barrier Integrity and Function In Vitro

Human immunodeficiency (HIV) infection results in neurocognitive deficits in about one half of infected individuals. Despite systemic effectiveness, restricted antiretroviral penetration across the blood-brain barrier (BBB) is a major limitation in fighting central nervous system (CNS)-localized infection. Drug abuse exacerbates HIV-induced cognitive and pathological CNS changes. This study's purpose was to investigate the effects of the HIV-1 protein Tat and methamphetamine on factors affecting drug penetration across an in vitro BBB model. Factors affecting paracellular and transcellular flux in the presence of Tat and methamphetamine were examined. Transendothelial electrical resistance, ZO-1 expression, and lucifer yellow (a paracellular tracer) flux were aspects of paracellular processes that were examined. Additionally, effects on P-glycoprotein (P-gp) and multidrug resistance protein 1 (MRP-1) mRNA (via quantitative PCR [qPCR]) and protein (via immunoblotting) expression were measured; Pgp and MRP-1 are drug efflux proteins. Transporter function was examined after exposure of Tat with or without methamphetamine using the P-gp substrate rhodamine 123 and also using the dual P-gp/MRP-1 substrate and protease inhibitor atazanavir. Tat and methamphetamine elicit complex changes affecting transcellular and paracellular transport processes. Neither Tat nor methamphetamine significantly altered P-gp expression. However, Tat plus methamphetamine exposure significantly increased rhodamine 123 accumulation within brain endothelial cells, suggesting that treatment inhibited or impaired P-gp function. Intracellular accumulation of atazanavir was not significantly altered after Tat or methamphetamine exposure. Atazanavir accumulation was, however, significantly increased by simultaneous inhibition of P-gp and MRP. Collectively, our investigations indicate that Tat and methamphetamine alter aspects of BBB integrity without affecting net flux of paracellular compounds. Tat and methamphetamine may also affect several aspects of transcellular transport.

Sex Matters: Robust Sex Differences in Signal Detection in the HIV-1 Transgenic Rat

Sex differences in human immunodeficiency virus type-1 (HIV-1) have been repeatedly suggested. Females, who account for 51% of HIV-1 seropositive individuals, are inadequately represented in clinical and preclinical studies, as well as in the description of HIV-1 associated neurocognitive disorders (HAND). Direct comparisons of neurocognitive decline in women and men must be made to address this underrepresentation. The effect of biological sex (i.e., the biological factors, including chromosomes and hormones, determining male or female characteristics; WHO, 2017) on sustained attention, which is commonly impaired in HIV-1 seropositive individuals, was investigated in intact HIV-1 transgenic (Tg) and control animals using a signal detection operant task. Analyses revealed a robust sex difference in the rate of task acquisition, collapsed across genotype, with female animals meeting criteria in shaping (at least 60 reinforcers for three consecutive or five non-consecutive sessions) and signal detection (70% accuracy for five consecutive or seven non-consecutive sessions) significantly more slowly than male animals. Presence of the HIV-1 transgene also had a significant effect on shaping and signal detection acquisition, with HIV-1 Tg animals displaying significant deficits in the rate of acquisition relative to control animals–deficits that were more prominent in female HIV-1 Tg animals. Once the animals’ reached asymptotic performance in the signal detection task, female animals achieved a lower percent accuracy across test sessions and exhibited a decreased response rate relative to male animals, although there was no compelling evidence for any effect of transgene. Results indicate that the factor of biological sex may be a moderator of the influence of the HIV-1 transgene on signal detection. Understanding the impact of biological sex on neurocognitive deficits in HIV-1 is crucial for the development of sex-based therapeutics and cure strategies.

Cognitive Impairment and Persistent CNS Injury in Treated HIV

The implementation of combination antiretroviral therapy (cART) has changed HIV infection into a chronic illness, conveying extensive benefits, including greater longevity and advantages for the central nervous system (CNS). However, studies increasingly confirm that the CNS gains are incomplete, with reports of persistent immune activation affecting the CNS despite suppression of plasma HIV RNA. The rate of cognitive impairment is unchanged, although severity is generally milder than in the pre-cART era. In this review, we discuss cognitive outcomes from recently published clinical HIV studies, review observations on HIV biomarkers for cognitive change, and emphasize longitudinal imaging findings. Additionally, we summarize recent studies on CNS viral invasion, CD8 encephalitis, and how CNS involvement during the earliest stages of infection may set the stage for later cognitive manifestations.

Evolution of the HIV-1 transgenic rat: utility in assessing the progression of HIV-1-associated neurocognitive disorders

Understanding the progression of HIV-1-associated neurocognitive disorders (HAND) is a critical need as the prevalence of HIV-1 in older individuals (>50 years) is markedly increasing due to the great success of combination antiretroviral therapy (cART). Longitudinal experimental designs, in comparison to cross-sectional studies, provide an opportunity to establish age-related disease progression in HAND. The HIV-1 transgenic (Tg) rat, which has been promoted for investigating the effect of long-term HIV-1 viral protein exposure, was used to examine two interrelated goals. First, to establish the integrity of sensory and motor systems through the majority of the animal's functional lifespan. Strong evidence for intact sensory and motor system function through advancing age in HIV-1 Tg and control animals was observed in cross-modal prepulse inhibition (PPI) and locomotor activity. The integrity of sensory and motor system function suggested the utility of the HIV-1 Tg rat in investigating the progression of HAND. Second, to assess the progression of neurocognitive impairment, including temporal processing and long-term episodic memory, in the HIV-1 Tg rat; the factor of biological sex was integral to the experimental design. Cross-modal PPI revealed significant alterations in the development of temporal processing in HIV-1 Tg animals relative to controls; alterations which were more pronounced in female HIV-1 Tg rats relative to male HIV-1 Tg rats. Locomotor activity revealed deficits in intrasession habituation, suggestive of a disruption in long-term episodic memory, in HIV-1 Tg animals. Understanding the progression of HAND heralds an opportunity for the development of an advantageous model of progressive neurocognitive deficits in HIV-1 and establishes fundamental groundwork for the development of neurorestorative treatments.

Geriatric syndromes: new frontiers in HIV and sarcopenia

: HIV infection, in many circumstances, can now be managed as a chronic disease due to the marked increase in life expectancy since the introduction of combination antiretroviral therapy (ART). As the patients who first had access to combination ART age into their 50s and 60s, the effects of chronic HIV infection on health have become an important research focus in HIV infection. People living with HIV appear to exhibit an earlier occurrence of some aging-related conditions compared to people without HIV, in part due to higher rates of comorbidities, high-risk behaviors (e.g. smoking, substance use), chronic immune activation, inflammation, and ART-specific factors. Some studies have even suggested an earlier-than-expected appearance of the 'geriatric syndromes,' which are complex medical syndromes of older adults that are associated with morbidity and mortality. The geriatric syndromes include a wide variety of disease processes ranging from incontinence and dementia to impairments in physical function. This review will focus on one geriatric syndrome, sarcopenia, in older HIV-infected populations, and its relation to other aging syndromes, including frailty and falls. The contribution of HIV itself, ART exposure, and specific comorbidities, and the importance of early recognition and prevention of these aging syndromes will be highlighted.

Heterogeneity of Neuropsychological Impairment in HIV Infection: Contributions from Mild Cognitive Impairment

Despite longstanding acknowledgement of the heterogeneity of HIV-associated neurocognitive disorders (HAND), existing HAND diagnostic methods classify according to the degree of impairment, without regard to the pattern of neuropsychological strengths and weaknesses. Research in mild cognitive impairment (MCI) has demonstrated that classifying individuals into subtypes by both their level and pattern of impairment, using either conventional or statistical methods, has etiologic and prognostic utility. Methods for characterizing the heterogeneity of MCI provide a framework that can be applied to other disorders and may be useful in clarifying some of the current challenges in the study of HAND. A small number of studies have applied these methods to examine the heterogeneity of neurocognitive function among individuals with HIV. Most have supported the existence of multiple subtypes of neurocognitive impairment, with some evidence for distinct clinicodemographic features of these subtypes, but a number of gaps exist. Following a review of diagnostic methods and challenges in the study of HAND, we summarize the literature regarding conventional and empirical subtypes of MCI and HAND and identify directions for future research regarding neurocognitive heterogeneity in HIV infection.

Accelerated and accentuated neurocognitive aging in HIV infection

There is debate as to whether the neurocognitive changes associated with HIV infection represent an acceleration of the typical aging process or more simply reflect a greater accentuated risk for age-related declines. We aimed to determine whether accelerated neurocognitive aging is observable in a sample of older HIV-infected individuals compared to age-matched seronegatives and older old (i.e., aged ≥65) seronegative adults. Participants in a cross-sectional design included 48 HIV-seronegative (O-) and 40 HIV-positive (O+) participants between the ages of 50-65 (mean ages = 55 and 56, respectively) and 40 HIV-seronegative participants aged ≥65 (OO-; mean age = 74) who were comparable for other demographics. All participants were administered a brief neurocognitive battery of attention, episodic memory, speeded executive functions, and confrontation naming (i.e., Boston Naming Test). The O+ group performed more poorly than the O- group (i.e., accentuated aging), but not differently from the OO- on digit span and initial recall of a supraspan word list, consistent with an accelerating aging profile. However, the O+ group's performance was comparable to the O- group on all other neurocognitive tests (ps > 0.05). These data partially support a model of accelerated neurocognitive aging in HIV infection, which was observed in the domain of auditory verbal attention, but not in the areas of memory, language, or speeded executive functions. Future studies should examine whether HIV-infected adults over 65 evidence accelerated aging in downstream neurocognitive domains and subsequent everyday functioning outcomes.

Clinical and viro-immunological correlates of HIV associated neurocognitive disorders (HAND) in a cohort of antiretroviral-naïve HIV-infected patients

The multifactorial pathogenesis of HIV-associated neurocognitive disorders may explain the inconsistent association between neurocognitive impairment and cerebrospinal fluid (CSF) HIV RNA. Clinical and viro-immunological (CSF and plasma HIV RNA, CSF/plasma HIV RNA ratio, circulating T-cell phenotypes) parameters were investigated in 155 HIV-infected, antiretroviral-naïve, asymptomatic study participants undergoing a neuropsychological evaluation. HIV associated neurocognitive disorders (HAND) was independently associated with AIDS events and a CSF/plasma ratio of at least one, after adjustment for CD4 nadir of less than 200 cells/mmc, suggesting a role for active central nervous system (CNS) viral replication in the pathogenesis of neurocognitive impairment.

Increased cell-free mitochondrial DNA is a marker of ongoing inflammation and better neurocognitive function in virologically suppressed HIV-infected individuals

Cell-free mitochondrial DNA (mtDNA) is a highly immunogenic molecule that is associated with several inflammatory conditions and with neurocognitive impairment during untreated HIV infection. Here, we investigate how cell-free mtDNA in cerebrospinal fluid (CSF) is associated with inflammation, neuronal damage, and neurocognitive functioning in the context of long-term suppressive antiretroviral therapy (ART). We quantified the levels of cell-free mtDNA in the CSF from 41 HIV-infected individuals with completely suppressed HIV RNA levels in blood plasma (<50 copies/mL) by droplet digital PCR. We measured soluble CD14, soluble CD163, interferon γ-induced protein 10 (IP-10), monocyte chemoattractant protein-1 (MCP-1), interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor-α (TNF-α), neopterin, and neurofilament light chain (NFL) by immunoassays in CSF supernatant or blood plasma. Higher levels of mtDNA in CSF were associated with higher levels of MCP-1 (r = 0.56, p < 0.01) in CSF and TNF-α (r = 0.43, p < 0.01) and IL-8 (r = 0.44, p < 0.01) in blood plasma. Subjects with a previous diagnosis of AIDS showed significantly higher levels of mtDNA (p < 0.01) than subjects without AIDS. The associations between mtDNA and MCP-1 in CSF and TNF-α in blood remained significant after adjusting for previous diagnosis of AIDS (p < 0.01). Additionally, higher levels of mtDNA were associated with a lower CD4 nadir (r = -0.41, p < 0.01) and lower current CD4% (r = -0.34, p = 0.03). Paradoxically, higher levels of mtDNA in CSF were significantly associated with better neurocognitive performance (r = 0.43, p = 0.02) and with less neuronal damage (i.e. lower NFL). Higher cell-free mtDNA is associated with inflammation during treated HIV infection, but the impact on neurocognitive functioning and neuronal damage remains unclear and may differ in the setting of suppressive ART.

Impairments in Component Processes of Executive Function and Episodic Memory in Alcoholism, HIV Infection, and HIV Infection with Alcoholism Comorbidity

BACKGROUND

Executive functioning and episodic memory impairment occur in HIV infection (HIV) and chronic alcoholism (ALC). Comorbidity of these conditions (HIV + ALC) is prevalent and heightens risk of vulnerability to separate and compounded deficits. Age and disease-related variables can also serve as mediators of cognitive impairment and should be considered, given the extended longevity of HIV-infected individuals in this era of improved pharmacological therapy.

METHODS

HIV, ALC, HIV + ALC, and normal controls (NC) were administered traditional and computerized tests of executive function and episodic memory. Test scores were expressed as age- and education-corrected Z-scores; selective tests were averaged to compute Executive Function and Episodic Memory Composite scores. Efficiency scores were calculated for tests with accuracy and response times.

RESULTS

HIV, ALC, and HIV + ALC had lower scores than NC on Executive Function and Episodic Memory Composites, with HIV + ALC even lower than ALC and HIV on the Episodic Memory Composite. Impairments in planning and free recall of visuospatial material were observed in ALC, whereas impairments in psychomotor speed, sequencing, narrative free recall, and pattern recognition were observed in HIV. Lower decision-making efficiency scores than NC occurred in all 3 clinical groups. In ALC, age and lifetime alcohol consumption were each unique predictors of Executive Function and Episodic Memory Composite scores. In HIV + ALC, age was a unique predictor of Episodic Memory Composite score.

CONCLUSIONS

Disease-specific and disease-overlapping patterns of impairment in HIV, ALC, and HIV + ALC have implications regarding brain systems disrupted by each disease and clinical ramifications regarding the complexities and compounded damping of cognitive functioning associated with dual diagnosis that may be exacerbated with aging.

Screening for Neurocognitive Impairment in HIV-Infected Individuals at First Contact after HIV Diagnosis: The Experience of a Large Clinical Center in Northern Italy

Neurocognitive disorders are emerging, probably underestimated, complications in HIV-infected people. The aim of the study was to assess neurocognitive profiles of newly detected HIV-infected patients. We performed an observational retrospective single-cohort study. Illiterates and patients with neurologic symptoms or previous psychiatric diagnosis were excluded. Neuropsychological profiles were assessed using a validated battery of neuropsychological tests. We included 206 patients; with males representing the majority of them (85%). Risk factors for HIV acquisition were unprotected sexual intercourse (homo/bisexual in 39.8% and heterosexual in 60.2%). Thirty-nine patients (18.9%) were previous injection drug users, while 41 (19.9%) were alcohol abusers. Mean education was 11.1 years (SD--standard deviation--3.7). A high prevalence of HIV-associated neurocognitive disorders (HAND, 47.1%) was present in HIV-infected patients: particularly, asymptomatic neurocognitive impairment (ANI) was found in 30.6%, mild neurocognitive disorder (MND) in 15% and HIV-associated dementia (HAD) in 1.5%. Male gender, low degree of education, AIDS diagnosis and gepatitis B virus (HBV) co-infection were factors independently associated with HAND in a multivariable logistic regression model. Our data suggest that patient-specific factors and AIDS diagnosis have a certain kind of impact in HAND occurrence. A complete neuropsychological screening must be recommended in all patients at HIV-infection diagnosis.

HIV and viral protein effects on the blood brain barrier

The blood brain barrier (BBB) plays a critical role in the normal physiology of the central nervous system (CNS) by regulating what crosses from the periphery into the brain. Damage to the BBB or alterations in transport systems may mediate the pathogenesis of many CNS diseases, including HIV-associated CNS dysfunction. HIV-1 infection can result in neuropathologic changes in about one half of infected individuals and also can result in damage to the BBB. HIV-1 and the HIV-1 viral proteins, Tat and gp120, cause alterations in the integrity and function of the BBB through both paracellular and transcellular mechanisms. The current review discusses HIV and viral protein-mediated injury to the BBB with a focus on the effects on tight junction proteins, barrier permeability, and drug efflux proteins.

Aging with HIV-1 Infection: Motor Functions, Cognition, and Attention--A Comparison with Parkinson's Disease

Recent advances in highly active anti-retroviral therapy (HAART) in their various combinations have dramatically increased the life expectancies of HIV-infected persons. People diagnosed with HIV are living beyond the age of 50 but are experiencing the cumulative effects of HIV infection and aging on brain function. In HIV-infected aging individuals, the potential synergy between immunosenescence and HIV viral loads increases susceptibility to HIV-related brain injury and functional brain network degradation similar to that seen in Parkinson's disease (PD), the second most common neurodegenerative disorder in the aging population. Although there are clear diagnostic differences in the primary pathology of both diseases, i.e., death of dopamine-generating cells in the substantia nigra in PD and neuroinflammation in HIV, neurotoxicity to dopaminergic terminals in the basal ganglia (BG) has been implied in the pathogenesis of HIV and neuroinflammation in the pathogenesis of PD. Similar to PD, HIV infection affects structures of the BG, which are part of interconnected circuits including mesocorticolimbic pathways linking brainstem nuclei to BG and cortices subserving attention, cognitive control, and motor functions. The present review discusses the combined effects of aging and neuroinflammation in HIV individuals on cognition and motor function in comparison with age-related neurodegenerative processes in PD. Despite the many challenges, some HIV patients manage to age successfully, most likely by redistribution of neural network resources to enhance function, as occurs in healthy elderly; such compensation could be curtailed by emerging PD.

Circulating HIV DNA Correlates With Neurocognitive Impairment in Older HIV-infected Adults on Suppressive ART

Older HIV-infected adults have a higher risk of neurocognitive impairment, but the underlying mechanisms are poorly understood. Here, we investigated the associations between levels of HIV DNA in peripheral blood, soluble markers of inflammation and cellular trafficking in blood and cerebrospinal fluid (CSF) and neurocognitive functioning among 18 younger (22–40 years) and 26 older (50–71 years) HIV-infected subjects, who were administered a comprehensive neurocognitive battery. Older HIV-infected individuals presented higher levels of inflammation in CSF and blood compared to younger individuals, but no difference was observed in HIV DNA levels. Among older participants, higher HIV DNA levels were significantly associated with more severe neurocognitive impairment (p = 0.005), particularly in the Executive Functions domain (p = 0.004). No association was observed between HIV DNA and neurocognition among younger individuals. Despite significantly increased inflammation observed in the older group, none of the inflammatory markers were associated with neurocognitive impairment among older HIV+ individuals (p > 0.05). Our study supports the involvement of peripheral HIV DNA reservoir in the pathogenesis of neurocognitive disorder during suppressive ART. Correlates of neurocognitive impairment might differ between younger and older adults, suggesting that future treatment and prevention strategies for HIV-associated neurocognitive disorders likely need to be tailored based on age.