Dynamics of cognitive change in impaired HIV-positive patients initiating antiretroviral therapy

The effect of antiretroviral therapy with high central nervous system penetration on HIV-related cognitive impairment: a systematic review and meta-analysis

Chronic complications are a significant concern for people living with HIV/AIDS (PLWHA) infection. HIV-associated neurocognitive disorders (HAND) are prevalent in PLWHA. Yet, the efficacy of medications that penetrate the central nervous system (CNS) at preventing or slowing the progression of HAND remains largely unknown. The objective of this study was to determine whether high CNS penetration effectiveness (CPE) regimens improve neurocognitive test scores in PLWHA on combined antiretroviral therapy (cART). Primary literature evaluating cognitive outcomes based on CPE score of cART regimens in PLWHA was assembled from PubMed/Medline and EMBASE. Both randomized controlled trials and observational studies with at least 12 weeks of follow-up were included. A meta-analysis was conducted to calculate the standardized mean difference. Eight trials including a total of 3,303 patients with 13,103 person-years of follow-up were included in the systematic review. Four trials (n = 366 patients) met our inclusion criteria and were included in the meta-analysis. In the meta-analysis, HIV regimens with a high CPE score did not affect NPZ-4 or GDS scores (standardized mean difference (SMD) 0.10, 95% CI -0.19, 0.38; I2 = 26%). Future studies with larger sample sizes are warranted to prospectively evaluate the relationship between CPE and progression of HAND.

Elevation of brain ADC (apparent diffusion coefficient) in HIV-associated neurocognitive disorders and evolution after treatment: A pilot study

BACKGROUND

Thirty to 50% of HIV-infected patients develop HIV-Associated Neurocognitive Disorders (HAND) despite virological control. The previously published Neuro+3 study showed their neurocognitive status can be improved by intensifying antiviral therapy. Our study is a part of the Neuro3+ study and aims to study apparent diffusion coefficient (ADC) as a biomarker for neurological improvement.

PATIENTS AND METHODS

We prospectively included 31 patients with HAND. They received therapy with better CNS Penetration Effectiveness (CPE) score with two-year follow-up. Cognitive status was assessed at day 0 (D0) and week 96 (W96) using Frascati 3-stage classification and Global Deficit Score (GDS). Brain MRI at D0 and W96 assessed morphological data (white matter hyperintensities, opportunistic infections, ischemic lesions, atrophy) and measured whole brain apparent diffusion coefficient (ADC). We compared their data with a control group of 20 healthy patients with similar ages and sex ratio.

RESULTS

After ARV intensification, cognitive status was significantly improved: GDS (n = 1,4 vs 1,0 p = 0.01) and Frascati scale (2HAD/22MND/7ANI vs 1HAD/8MND/17ANI p = 0.001). Mean ADC was significantly higher in patients at inclusion than in controls (0.88 × 10^-3 mm²/s ± 0.06 vs 0.81 × 10^-3 mm²/s ± 0.04, p = 0.0001). ADC decreased after treatment (0.88 × 10^-3 mm²/s ± 0.06 vs 0.85 × 10^-3 mm²/s ± 0.06 (p = 0,04). In subgroup analysis, ADC significantly decreased in clinically improved patients (0.89 × 10^-3 mm²/s ± 0.07 vs 0.85 × 10^-3 mm²/s ± 0.07 (p = 0,03)) and did not significantly change in non-clinically improved patients (0.86 × 10^-3 mm²/s ± 0.07 vs 0.84 × 10^-3 mm²/s ± 0.07 (p = 0,31)). After treatment, there was no significant difference between patients and controls (0.85 × 10^-3 mm²/s ± 0.06 vs 0.81 × 10^-3 mm²/s ± 0.04, p = 0.17).

CONCLUSION

Whole-brain ADC is a good biomarker of HIV-associated neurocognitive disorders. It is significantly increased in patients with HAND compared with controls and significantly decreases after treatment. It is all the more important to have a quantitative biomarker as conventional imaging does not contribute to the diagnosis.

Longitudinal Cognitive Outcomes in Children With HIV in Zambia: 2-Year Outcomes From the HIV-Associated Neurocognitive Disorders in Zambia (HANDZ) Study

OBJECTIVE

To describe longitudinal outcomes and predictors of cognitive outcomes in children with HIV in Zambia.

BACKGROUND

Multiple studies have shown that children with HIV are at risk for impaired cognition. However, there are limited data on longitudinal cognitive outcomes in children with HIV.

METHODS

We conducted a prospective cohort study of 208 perinatally infected children with HIV ages 8-17 years, all treated with antiretroviral therapy, and 208 HIV-exposed uninfected controls. Participants were followed for 2 years. Cognition was assessed with a custom NIH Toolbox Cognition Battery, and tests were combined to generate a Summary Cognition Score (SCS). The contribution of potential risk factors to outcomes was explored using regression models and group-based trajectory modeling.

RESULTS

HIV was strongly associated with lower SCS at baseline [β-14, 95% confidence interval (CI): -20 to -7, P < 0.001]. Change scores over time were similar between groups, but poorer average performance in children with HIV persisted at the 2-year follow-up visit (adjusted β = -11, 95% CI: -22 to -0.3, P = 0.04). Other than HIV, the strongest predictors of baseline SCS included socioeconomic status index (β =3, 95% CI: 1, 5, P = 0.004), history of growth stunting (β=-14, 95% CI: -23 to -6, P = 0.001), history of CD4 count below 200 (β = -19, 95% CI: -35 to -2, P = 0.02), and history of World Health Organization stage 4 disease (β = -10, 95% CI: -19 to -0.2, P = 0.04). In the group-based trajectory model, HIV+ status predicted membership in the lowest performing trajectory group (odds ratio 2.5, 95% CI: 1.2 to 5.1, P = 0.01).

CONCLUSIONS

Children with HIV are at risk of poor cognitive outcomes, despite chronic treatment with antiretroviral therapy.

Altered white matter integrity in the corpus callosum in adults with HIV: a systematic review of diffusion tensor imaging studies

We systematically reviewed studies comparing differences in the integrity of the corpus callosum in adults with HIV compared to healthy controls, using Diffusion Tensor Imaging (DTI), using search engines Science Direct, Web of Science and PubMed. The search terms used were "HIV", "corpus callosum", and a variation of either "DTI" or "Diffusion Tensor Imaging" with or without the term "adults". We specifically examined the corpus callosum as it is the largest white matter tract in the brain, plays a primary role in cognition, and has been shown to be morphologically altered in people living with HIV. Lower fractional anisotropy (FA) was consistently found in the corpus callosum in people with HIV compared to controls. As most studies used only FA as a measure of diffusion, it would be informative for future research if other DTI metrics, such as mean diffusivity (MD), were also investigated as these metrics may be more sensitive markers of HIV-related neuropathology.

Risk of Falls in HIV-Infected Patients on Antiretroviral Therapy and Its Associated Factors

Purpose

Methods

Results

Conclusion

Longitudinal Effects of Combination Antiretroviral Therapy on Cognition and Neuroimaging Biomarkers in Treatment-Naïve People with HIV

BACKGROUND AND OBJECTIVES

While combination antiretroviral therapy (cART) has dramatically increased the life expectancy of people with HIV (PWH), nearly 50% develop HIV-associated neurocognitive disorders (HAND)¹. This may be due to previously uncontrolled HIV viral replication, immune activation maintained by residual viral replication² or activation from other sources^{3, 4}, or cART-associated neurotoxicity⁵. The aim of this study was to determine the effect of cART on cognition and neuroimaging biomarkers markers in people with HIV (PWH) before and after initiation of cART compared to HIV negative controls (HC) and HIV elite controllers (EC) who remain untreated.

METHODS

We recruited three groups of participants from the University of Rochester, McGovern Medical School and SUNY Upstate Medical University: 1) ART-treatment-naïve PWH; 2) age-matched HC; and 3) EC. Participants underwent brain MRI and clinical and neuropsychological assessments at baseline, one year, and two years. PWH were also assessed 12 weeks after initiating cART. Volumetric analysis and fractal dimensionality (FD) were calculated for cortical and subcortical regions. Mixed effect regressions examined the effect of group and imaging variables on cognition.

RESULTS

We enrolled 47 PWH, 58 HC, and 10 EC. At baseline, PWH had worse cognition and lower cortical volumes than HC. Cognition improved following initiation of cART and remained stable over time. Greater cortical thickness was associated with better cognition at baseline; greater FD of parietal, temporal and occipital lobes was associated with better cognition at baseline and longitudinally. At baseline, EC had worse cognition, lower cortical thickness and lower FD in all four lobes and caudate than PWH and HC. Greater cortical thickness, hippocampal volumes and FD of frontal, temporal and occipital lobes were associated with better cognition longitudinally.

CONCLUSIONS

Initiation of cART in PWH is associated with improvement in brain structure and cognition. However, significant differences persist over time compared to HC. Similar trends in EC suggest that results are due to HIV infection rather than treatment. Stronger associations between cognition and FD suggest this imaging metric may be a more sensitive marker of neuronal injury than cortical thickness and volumetric measures.

HIV Antiretroviral Medication Neuropenetrance and Neurocognitive Outcomes in HIV+ Adults: A Review of the Literature Examining the Central Nervous System Penetration Effectiveness Score

This literature review summarizes the existing research examining the CNS penetration effectiveness (CPE) score and neurocognitive outcomes (i.e., neuropsychological assessment and neurocognitive screening) in HIV+ individuals. Despite the effectiveness of Combined Antiretroviral Therapy (CART) in reducing mortality and morbidity in HIV and controlling viral replication, HIV often persists in the Central Nervous System (CNS), and rates of neurocognitive impairment remain higher than predicted in the post-CART era. The CPE score was developed to rank antiretroviral regimens on their ability to penetrate the CNS and potency in inhibiting the virus, and it has been examined in relation to neurocognitive functioning for over a decade. Based on the results of 23 studies, we conclude that CPE is not as strongly associated with neurocognitive outcomes as initially hypothesized, although higher CPE ARV regimens may be associated with modest, improved outcomes in global neurocognitive functioning, and to a lesser extent attention/working memory and learning/memory. Conclusions, however, are limited by the heterogeneity in study design and methods, and the lack of a more recent CPE metric update. It is recommended that future research in this area employ comprehensive, standardized neuropsychological test batteries and examine domain-level performance, and use the newer 2010 CPE metric, although an updated CPE ranking is urgently needed.

Reduced Gut Microbiome Diversity in People With HIV Who Have Distal Neuropathic Pain

Gut dysbiosis, defined as pathogenic alterations in the distribution and abundance of different microbial species, is associated with neuropathic pain in a variety of clinical conditions, but this has not been explored in the context of neuropathy in people with HIV (PWH). We assessed gut microbial diversity and dysbiosis in PWH and people without HIV (PWoH), some of whom reported distal neuropathic pain (DNP). DNP was graded on a standardized, validated severity scale. The gut microbiome was characterized using 16S rRNA sequencing and diversity was assessed using phylogenetic tree construction. Songbird analysis (https://github.com/mortonjt/songbird) was used to produce a multinomial regression model predicting counts of specific microbial taxa through metadata covariate columns. Participants were 226 PWH and 101 PWoH, mean (SD) age 52.0 (13.5), 21.1% female, 54.7% men who have sex with men, 44.7% non-white. Among PWH, median (interquartile range, IQR) nadir and current CD4 were 174 (21, 302) and 618 (448, 822), respectively; 90% were virally suppressed on antiretroviral therapy. PWH and PWoH did not differ with respect to microbiome diversity as indexed by Faith's phylogenetic diversity (PD). More severe DNP was associated with lower alpha diversity as indexed by Faith's phylogenetic diversity in PWH (Spearman's ρ = .224, P = 0.0007), but not in PWoH (Spearman's ρ = .032, P = .748). These relationships were not confounded by demographics or disease factors. In addition, the log-ratio of features identified at the genus level as Blautia to Lachnospira was statistically significantly higher in PWH with DNP than in PWH without DNP (t-test, P = 1.01e-3). Furthermore, the log-ratio of Clostridium features to Lachnospira features also was higher in PWH with DNP than in those without (t-test, P = 6.24e-5). Our results, in combination with previous findings in other neuropathic pain conditions, suggest that gut dysbiosis, particularly reductions in diversity and relative increases in the ratios of Blautia and Clostridium to Lachnospira, may contribute to prevalent DNP in PWH. Two candidate pathways for these associations, involving microbial pro-inflammatory components and microbially-produced anti-inflammatory short chain fatty acids, are discussed. Future studies might test interventions to re-establish a healthy gut microbiota and determine if this prevents or improves DNP. PERSPECTIVE: The association of neuropathic pain in people with HIV with reduced gut microbial diversity and dysbiosis raises the possibility that re-establishing a healthy gut microbiota might ameliorate neuropathic pain in HIV by reducing proinflammatory and increasing anti-inflammatory microbial products.

Lentiviral Infections Persist in Brain despite Effective Antiretroviral Therapy and Neuroimmune Activation

HIV infection persists in different tissue reservoirs among people with HIV (PWH) despite effective antiretroviral therapy (ART). In the brain, lentiviruses replicate principally in microglia and trafficking macrophages. The impact of ART on this viral reservoir is unknown. We investigated the activity of contemporary ART in various models of lentivirus brain infection. HIV-1 RNA and total and integrated DNA were detected in cerebral cortex from all PWH (n = 15), regardless of ART duration or concurrent plasma viral quantity and, interestingly, integrated proviral DNA levels in brain were significantly higher in the aviremic ART-treated group (P < 0.005). Most ART drugs tested (dolutegravir, ritonavir, raltegravir, and emtricitabine) displayed significantly lower 50% effective concentration (EC₅₀) values in lymphocytes than in microglia, except tenofovir, which showed 1.5-fold greater activity in microglia (P < 0.05). In SIV-infected Chinese rhesus macaques, despite receiving suppressive (n = 7) or interrupted (n = 8) ART, brain tissues had similar SIV-encoded RNA and total and integrated DNA levels compared to brains from infected animals without ART (n = 3). SIV and HIV-1 capsid antigens were immunodetected in brain, principally in microglia/macrophages, regardless of ART duration and outcome. Antiviral immune responses were comparable in the brains of ART-treated and untreated HIV- and SIV-infected hosts. Both HIV-1 and SIV persist in brain tissues despite contemporary ART, with undetectable virus in blood. ART interruption exerted minimal effect on the SIV brain reservoir and did not alter the neuroimmune response profile. These studies underscore the importance of augmenting ART potency in different tissue compartments. IMPORTANCE Antiretroviral therapy (ART) suppresses HIV-1 in plasma and CSF to undetectable levels. However, the impact of contemporary ART on HIV-1 brain reservoirs remains uncertain. An active viral reservoir in the brain during ART could lead to rebound systemic infection after cessation of therapy, development of drug resistance mutations, and neurological disease. ART's impact, including its interruption, on brain proviral DNA remains unclear. The present studies show that in different experimental platforms, contemporary ART did not suppress viral burden in the brain, regardless of ART component regimen, the duration of therapy, and its interruption. Thus, new strategies for effective HIV-1 suppression in the brain are imperative to achieve sustained HIV suppression.

An assessment of factors associated with neurocognitive decline in people living with HIV

Despite the widespread use of combination antiretroviral therapy (cART), HIV-associated neurocognitive impairment (NCI) remains a health concern. However, limited research has been done to identify factors associated with neurocognitive decline. We assessed risk factors associated with neurocognitive decline in people living with HIV using a definition of decline that is statistically easy to adopt, is based on a commonly used neuropsychological cut-off and may be clinically relevant. Cox proportional hazards modeling was performed using the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) study database. 581 participants were followed for up to 12 years. Neurocognitive decline was defined as the first observed drop in global T-scores of at least 2.67. Lifetime methamphetamine use had the strongest association with neurocognitive decline (adjusted Hazard Ratio; aHR = 1.48; 95% CI = 0.92-2.39) followed by no current antiretroviral medication use (aHR = 1.32; 95% CI = 0.91-1.92). Other risk factors included Hispanic ethnicity, lifetime history of major depressive disorder, lifetime cannabis use, hepatitis-C infection, and difficulty eating, dressing, bathing, or using the toilet. Results indicate that consistent use of ART may be of high significance to preserving neurocognition. Furthermore, Hispanic patients, those with a history of depression and substance use, and those having difficulty in essential activities of daily living may require vigilant follow-up.

Associations between plasma nucleoside reverse transcriptase inhibitors concentrations and cognitive function in people with HIV

Objectives

To investigate the associations of plasma lamivudine (3TC), abacavir (ABC), emtricitabine (FTC) and tenofovir (TFV) concentrations with cognitive function in a cohort of treated people with HIV (PWH).

Methods

Pharmacokinetics (PK) and cognitive function (Cogstate, six domains) data were obtained from PWH recruited in the POPPY study on either 3TC/ABC or FTC/tenofovir disoproxil fumarate (TDF)-containing regimens. Association between PK parameters (AUC_0-24: area under the concentration-time curve over 24 hours, C_max: maximum concentration and C_trough: trough concentration) and cognitive scores (standardized into z-scores) were evaluated using rank regression adjusting for potential confounders.

Results

Median (IQR) global cognitive z-scores in the 83 PWH on 3TC/ABC and 471 PWH on FTC/TDF were 0.14 (-0.27, 0.38) and 0.09 (-0.28, 0.42), respectively. Higher 3TC AUC_0-24 and C_trough were associated with better global z-scores [rho = 0.29 (p = 0.02) and 0.27 (p = 0.04), respectively], whereas higher 3TC C_max was associated with poorer z-scores [rho = -0.31 (p<0.01)], independently of ABC concentrations. Associations of ABC PK parameters with global and domain z-scores were non-significant after adjustment for confounders and 3TC concentrations (all p’s>0.05). None of the FTC and TFV PK parameters were associated with global or domain cognitive scores.

Conclusions

Whilst we found no evidence of either detrimental or beneficial effects of ABC, FTC and TFV plasma exposure on cognitive function of PWH, higher plasma 3TC exposures were generally associated with better cognitive performance although higher peak concentrations were associated with poorer performance.

Interrogating the impact of combination antiretroviral therapies on HIV-associated neurocognitive disorders

OBJECTIVES

Although the advent of Combination Antiretroviral Therapy (cART) has greatly reduced the prevalence of HIV-Associated Dementia, the most severe form of HIV-Associated Neurocognitive Disorder (HAND), the incidence of the milder forms of HAND have risen. The explanations proposed include persistent central nervous system (CNS) viraemia and the neurotoxicity of chronic cART regimens. Nonetheless, controversies in HAND prevalence estimates, alongside a lack of consensus on the significance of CNS Penetration Effectiveness (CPE) have added to the complexity of elucidating the role of cART in HAND. The present review will evaluate the evidence underlying these explanations, as well as highlighting the need for improved trial designs and the incorporation of emerging biomarkers and neuroimaging tools.

METHODS

A review of the current literature investigating cART neurotoxicity, controversies in HAND prevalence estimates, CNS Penetration Effectiveness, and neuroprotective adjuvant therapies.

CONCLUSIONS

Ultimately, the inadequacy of cART in achieving complete preservation of the CNS underscores the imminent need for neuroprotective adjuvant therapies, where the efficacy of combining multiple adjuvant classes presents a potential therapeutic frontier which must be interrogated.

Improvement of HIV-associated neurocognitive disorders after antiretroviral therapy intensification: the Neuro+3 study

OBJECTIVES

Despite the effectiveness of antiretroviral (ARV) therapy to control HIV infection, HIV-associated neurocognitive disorders (HAND) remain frequent. The Neuro+3 study assessed the cognitive improvement associated with ARV intensification based on increased CNS penetration effectiveness (CPE) scoring ≥+3 and total CPE score ≥9.

METHODS

Thirty-one patients, aged 18-65 years, with confirmed diagnosis of HAND and effective ARV therapy were included. The cognitive improvement was measured using Frascati three-stage classification and global deficit score (GDS) after 48 and 96 weeks of ARV intensification. Ultrasensitive HIV-RNA, neopterin, soluble CD14, CCL2, CXCL10, IL6, IL8 and NF-L were measured in plasma and cerebrospinal fluid at Day 0 (baseline), Week 48 (W48) and W96.

RESULTS

The intensified ARV was associated with a median (IQR) CPE score increase from 6 (4-7) at baseline to 10 (9-11). From baseline to W96, the median (IQR) GDS decreased from 1.4 (0.8-2.2) to 1.0 (0.6-2.0) (P = 0.009); HAND classification improved from 2 to 1 HIV-associated dementia, 22 to 8 mild neurocognitive disorders, 7 to 17 asymptomatic neurocognitive impairment and 0 to 5 patients without any neurocognitive alterations (P = 0.001). In multivariable linear regression analysis, GDS improvement at W96 was significantly associated with CPE score ≥9 after intensification (P = 0.014), CD4 lymphocyte increase at W48 (P < 0.001) and plasma CXCL10 decrease at W96 (P = 0.001).

CONCLUSIONS

In patients with HAND, a significant cognitive improvement was observed after the ARV intensification strategy, with a higher CPE score. Cognitive improvement was more often observed in the case of a switch of two drug classes, arguing for better control of CNS HIV immune activation.

Neurocognitive Trajectories After 72 Weeks of First-Line Anti-retroviral Therapy in Vietnamese Adults With HIV-HCV Co-infection

Background: Long-term neurocognitive outcomes following first-line suppressive anti-retroviral therapy (ART) remain uncertain for individuals with HIV and hepatitis C (HCV) co-infection. The study examined neurocognitive performance before and after 72 weeks of ART using repeated multivariate analyses and latent trajectory models.

Methods: One hundred and sixty adults with chronic, untreated HIV infection (n = 80 with HCV co-infection and n = 80 HIV mono-infected) and 80 demographically similar healthy controls were recruited from the Hospital for Tropical Diseases in Ho Chi Minh City and the surrounding community, respectively. Neurocognitive measures (adapted for use in Vietnam) and liver enzyme tests were compared across groups at baseline. Repeated multivariate and group-based trajectory analyses (GBTA) examined neurocognitive subgroup profiles of the co-infected individuals after 72 weeks of de novo efavirenz- (n = 41) or raltegravir-based (n = 39) ART.

Results: Baseline analyses revealed worse motor function in HIV-HCV co-infected individuals compared to both comparison groups. Longitudinal analyses revealed improved neurocognitive performance by week 48 for most participants regardless of treatment arm. GBTA identified a subgroup (35% of HIV-HCV sample) with persistent motor impairment despite otherwise successful ART. Higher HIV viral load and lower CD4⁺ T cell count at baseline predicted persistent motor dysfunction. Liver indices and ART regimen did not predict neurocognitive outcomes in HIV-HCV co-infected individuals.

Conclusions: Most HIV-HCV co-infected individuals achieve normative neurocognitive performance after 48 weeks of de novo suppressive ART. However, individuals with more severe HIV disease prior to ART exhibited motor impairment at baseline and 72 weeks after otherwise successful treatment. Interventions aimed at improving motor symptoms at the time of HIV treatment onset may improve long-term clinical outcomes in HIV-HCV co-infected adults.

Neurocognitive Trajectories After 72 Weeks of First-Line Anti-retroviral Therapy in Vietnamese Adults With HIV-HCV Co-infection

Background: Long-term neurocognitive outcomes following first-line suppressive anti-retroviral therapy (ART) remain uncertain for individuals with HIV and hepatitis C (HCV) co-infection. The study examined neurocognitive performance before and after 72 weeks of ART using repeated multivariate analyses and latent trajectory models.

Methods: One hundred and sixty adults with chronic, untreated HIV infection (n = 80 with HCV co-infection and n = 80 HIV mono-infected) and 80 demographically similar healthy controls were recruited from the Hospital for Tropical Diseases in Ho Chi Minh City and the surrounding community, respectively. Neurocognitive measures (adapted for use in Vietnam) and liver enzyme tests were compared across groups at baseline. Repeated multivariate and group-based trajectory analyses (GBTA) examined neurocognitive subgroup profiles of the co-infected individuals after 72 weeks of de novo efavirenz- (n = 41) or raltegravir-based (n = 39) ART.

Results: Baseline analyses revealed worse motor function in HIV-HCV co-infected individuals compared to both comparison groups. Longitudinal analyses revealed improved neurocognitive performance by week 48 for most participants regardless of treatment arm. GBTA identified a subgroup (35% of HIV-HCV sample) with persistent motor impairment despite otherwise successful ART. Higher HIV viral load and lower CD4+ T cell count at baseline predicted persistent motor dysfunction. Liver indices and ART regimen did not predict neurocognitive outcomes in HIV-HCV co-infected individuals.

Conclusions: Most HIV-HCV co-infected individuals achieve normative neurocognitive performance after 48 weeks of de novo suppressive ART. However, individuals with more severe HIV disease prior to ART exhibited motor impairment at baseline and 72 weeks after otherwise successful treatment. Interventions aimed at improving motor symptoms at the time of HIV treatment onset may improve long-term clinical outcomes in HIV-HCV co-infected adults.

Interaction of APOE, cerebral blood flow, and cortical thickness in the entorhinal cortex predicts memory decline

The ε4 allele of the apolipoprotein E (APOE) gene, a risk factor for cognitive decline, is associated with alterations in medial temporal lobe (MTL) structure and function, yet little research has been dedicated to understanding how these alterations might interact to negatively impact cognition. To bridge this gap, the present study employed linear regression models to determine the extent to which APOE genotype (ε4+, ε4-) modifies interactive effects of baseline arterial spin labeling MRI-measured cerebral blood flow (CBF) and FreeSurfer-derived cortical thickness/volume (CT/Vo) in two MTL regions of interest (entorhinal cortex, hippocampus) on memory change in 98 older adults who were cognitively normal at baseline. Baseline entorhinal CBF was positively associated with memory change, but only among ε4 carriers with lower entorhinal CT. Similarly, baseline entorhinal CT was positively associated with memory change, but only among ε4 carriers with lower entorhinal CBF. Findings suggest that APOE ε4 carriers may experience concomitant alterations in neurovascular function and morphology in the MTL that interact to negatively affect cognition prior to the onset of overt clinical symptoms. Results also suggest the presence of distinct multimodal neural signatures in the entorhinal cortex that may signal relative risk for cognitive decline among this group, perhaps reflecting different stages of cerebrovascular compensation (early effective vs. later ineffective).

EEG event related potentials in sustained, focused and divided attention tasks: Potential biomarkers for cognitive impairment in HIV patients

OBJECTIVES

The objective of this study was to assess the usability of event-related-potentials (ERPs) during sustained, focused, and divided attention tasks as biomarkers for cognitive decline in HIV patients.

METHODS

EEG was acquired using a mobile/wireless 9-channel system in 39 persons with HIV, with well-controlled immune function and 63 healthy control participants (HCs) during three ERP tasks: sustained attention, focused attention, and divided attention.

RESULTS

The HIV-group evidenced smaller late positive potential (LPP) and larger P200 amplitudes across the tasks compared to the HC group. P200 amplitude was correlated (r = 0.56) with the estimated duration of infection. Both groups showed higher P200 and LPP amplitudes in response to infrequent stimuli; this effect was not significantly different between groups. In the sustained attention task, the HIV-group showed significantly slower reaction time than controls while maintaining the same level of accuracy. In the divided attention task, the HIV-group showed a trend towards faster/less accurate responses.

CONCLUSIONS

HIV seropositive participants receiving anti-retroviral treatment (ART) demonstrated significantly larger P200 amplitude during three different attention tasks. This may reflect attentional deficits characterized by over-attending to non-target/distracting stimuli.

SIGNIFICANCE

These findings demonstrate the potential benefits of EEG-ERP metrics derived from attention tasks as neurocognitive biomarkers for HIV. This approach may reveal underlying causes of attentional deficits in HIV patients.

Alzheimer's disease-like perturbations in HIV-mediated neuronal dysfunctions: understanding mechanisms and developing therapeutic strategies

Excessive exposure to toxic substances or chemicals in the environment and various pathogens, including viruses and bacteria, is associated with the onset of numerous brain abnormalities. Among them, pathogens, specifically viruses, elicit persistent inflammation that plays a major role in Alzheimer's disease (AD) as well as dementia. AD is the most common brain disorder that affects thought, speech, memory and ability to execute daily routines. It is also manifested by progressive synaptic impairment and neurodegeneration, which eventually leads to dementia following the accumulation of Aβ and hyperphosphorylated Tau. Numerous factors contribute to the pathogenesis of AD, including neuroinflammation associated with pathogens, and specifically viruses. The human immunodeficiency virus (HIV) is often linked with HIV-associated neurocognitive disorders (HAND) following permeation through the blood-brain barrier (BBB) and induction of persistent neuroinflammation. Further, HIV infections also exhibited the ability to modulate numerous AD-associated factors such as BBB regulators, members of stress-related pathways as well as the amyloid and Tau pathways that lead to the formation of amyloid plaques or neurofibrillary tangles accumulation. Studies regarding the role of HIV in HAND and AD are still in infancy, and potential link or mechanism between both is not yet established. Thus, in the present article, we attempt to discuss various molecular mechanisms that contribute to the basic understanding of the role of HIV-associated neuroinflammation in AD and HAND. Further, using numerous growth factors and drugs, we also present possible therapeutic strategies to curb the neuroinflammatory changes and its associated sequels.

Diffusion tensor magnetic resonance imaging of white matter integrity in patients with HIV-associated neurocognitive disorders

Background

This study investigated the efficacy and neurotoxicity of highly active antiretroviral therapy (HAART) by evaluating white matter (WM) injury using diffusion tensor magnetic resonance imaging (DTI) in patients with human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND).

Methods

Forty-six patients with HAND underwent DTI before and every six months during HAART treatment. DTI data, including fractional anisotropy (FA) and mean diffusivity (MD) values of structural WM before and after HAART, were compared. The relationship between DTI values and plasma viral loads was tested. MD was more sensitive than FA for evaluating WM injury in HAND-positive patients.

Results

Following 12 months of HAART, increased MD values (compared to 6 months of HAART) were observed in the right temporal lobe, right parietal lobe, right occipital lobe, right anterior limb of the internal capsule, right lenticular nucleus, the right cerebral peduncle, left caudate nucleus, left dorsal thalamus, and left posterior limb of the internal capsule. MD values in the left genu of the internal capsule (r=0.350, P=0.017) and left corona radiata (r=0.338, P=0.021) were positively correlated with plasma viral loads.

Conclusions

DTI may be useful for assessing the efficacy and neurotoxicity of HAART in HAND-positive patients. Starting HAART may halt WM injury; however, prolonged HAART could worsen WM injury, highlighting the importance of optimal HAART duration.

Factors Predicting Detrimental Change in Declarative Memory Among Women With HIV: A Study of Heterogeneity in Cognition

Objective

Statistical techniques used to study cognitive function in HIV typically yield normative estimates and can mask the heterogeneity in cognitive trajectories over time. We applied a novel statistical approach to identify clusters of individuals with distinct patterns of change in declarative memory in HIV-seropositive (HIV+) and HIV-seronegative (HIV−) women.

Methods

1731 women from the Women’s Interagency HIV Study, a multi-center, prospective cohort study, completed the Hopkins Verbal Learning Test-Revised (HLVT-R) at >2 visits. To derive subgroups with similar patterns of decline by HIV-serostatus, we used a mixed-effects framework that modeled the trajectory of multiple declarative memory outcomes over time, while simultaneously clustering individuals.

Results

Of the 1731 participants, 1149 were HIV+ (70% Black/African American [AA]; 30% White/Other [W/O]) and 582 were HIV− (68% AA; 32% W/O). Race stratification was necessary to optimize clustering. Among HIV+AA’s, four subgroups emerged: a subgroup with minimal decline, two with accelerated decline, and one with stable but low performance. In HIV− AA, three subgroups emerged: one with minimal decline and two with accelerated decline. In multivariable-adjusted models among HIV+, individuals with accelerated decline were less educated (P < 0.001) and more likely to have a history of depression (P < 0.001) versus those with minimal decline. Similar subgroups were identified in W/O HIV+ and W/O HIV− participants.

Conclusion

We identified clinically meaningful subgroups of women with distinct phenotypes of declarative memory decline, which depend on race and HIV-serostatus using a data driven approach. Identification of underlying mechanisms and risk factors contributing to the observed differences are warranted. More broadly our modeling approach could be other populations to identify risk factors for accelerated cognitive decline and to personalize interventions.

Cognitive and Neurologic Rehabilitation Strategies for Central Nervous System HIV Infection

PURPOSE OF REVIEW

Cognitive impairment leading to disability is increasingly seen in people living with human immunodeficiency virus (PLWH). Rehabilitation can alleviate the effects of cognitive impairment upon function. The aim of this paper is to discuss the strategies that have been used in cognitive and neurologic rehabilitation in PLWH.

RECENT FINDINGS

Studies examining pharmacological and non-pharmacological strategies were analysed. Medical management of HIV and co-morbidities should be optimised. Non-pharmacological strategies, including nerve stimulation techniques, exercise-based interventions, and paper and computer-based cognitive rehabilitation, have some evidence supporting their use in PLWH either as stand-alone interventions or as part of a multidisciplinary approach. Both pharmacological and non-pharmacological rehabilitation strategies have been used with PLWH. More intervention trials are needed to assess cognitive and neurological rehabilitation strategies and further evaluate their potential benefit in PLWH.

State of the Mind: Growing up with HIV

Human immunodeficiency virus (HIV) is a neurotropic virus that has a detrimental impact on the developing central nervous system (CNS) of children growing up with perinatal HIV (PHIV) due to a combination of pathophysiological processes related to direct viral cytopathic effects and immune activation. This leads to a spectrum of neurocognitive impairment ranging from severe encephalopathy to subtle domain-specific cognitive impairments, as well as psychological disorders that are compounded by HIV-related stigma and sociodemographic factors that disproportionately affect PHIV children. Early commencement and consistent use of combination antiretroviral therapy (cART) has resulted in a dramatic improvement in neuropsychological outcomes for PHIV children; however, they remain vulnerable to cognitive impairment and psychological disorders, as evidenced by imaging findings, randomised clinical trials and observational studies. An optimal neuroprotective cART regimen remains elusive in children, but systemic viral suppression, regular neurocognitive and psychological screening and ready access to neuropsychological management strategies are key components for optimising neuropsychological outcomes. However, a lack of standardised and validated screening tools, particularly in resource-limited settings, hinders a precise understanding of the nature, prevalence and associations between neuropsychological symptomatology and HIV health. This article reviews the natural history, cellular pathophysiology and structural and functional imaging findings for children growing up with HIV, as well as summarising management strategies related to antiretroviral therapy, screening tools and specific interventions for neurocognitive impairments and psychological disorders.

HIV-associated neurocognitive disorders at Moi teaching and referral hospital, Eldoret, Kenya

Background

Human Immunodeficiency Virus (HIV) infection causes a myriad of neurological complications including cognitive deficits referred to as HIV-Associated Neurocognitive Disorders (HAND). With the introduction of combination antiretroviral therapy, there has been an epidemiological shift in cognitive disorders with a decline in the more severe HIV-Associated Dementia (HAD) to an increase in the less severe HAND: Asymptomatic Neurocognitive Impairment (ANI) and HIV-associated Mild Neurocognitive Disorder (MND). Central Nervous System (CNS) involvement in HIV interferes with cognitively demanding activities of daily living and hence a worse quality of life. Early diagnosis is delayed until symptoms are overt.

Methods

We conducted a cross sectional analytical study of HIV infected persons on antiretroviral therapy attending HIV clinic. A systematic random sampling was done to select 360 patients. An interviewer administered structured questionnaire was used to collect socio-demographic data while the CD4 count and viral load were retrieved from the Academic Model Providing Access to Healthcare (AMPATH) database. Pearson’s Chi Square test was used to compare proportions while independent sample t- test was used to compare continuous variables between the patients diagnosed with HAND and those without HAND. Logistic regression model was used to assess the factors associated with HAND.

Results

The mean age of the study participants was 40.2 years. The overall prevalence of HAND was (81.1%) N = 292. Mild HAND (ANI and MND) was present (78.6%) N = 283, Severe HAND (HAD) (2.5%) N = 9. The factors associated with HAND were older age OR: 1.06 (95% CI: 1.03, 1.10), male gender OR: 0.48 (95% CI: 0.24, 0.97), Advanced WHO clinical staging OR: 2.45 (95% CI: 1.20, 5.01) and a higher level of education; secondary/tertiary OR: 0.16 (95% CI: 0.07, 0.38); 0.11 (95% CI: 0.04, 0.35).

Conclusion

The prevalence of HAND in this study population was found to be high (81.1%). Older age and advanced WHO clinical staging were associated with an increased risk of hand while higher level of education and male gender were protective.

Predictors of worsening neuropathy and neuropathic pain after 12 years in people with HIV

OBJECTIVE

Distal sensory polyneuropathy (DSP) and neuropathic pain are important clinical concerns in virally suppressed people with HIV. We determined how these conditions evolved, what factors influenced their evolution, and their clinical impact.

METHODS

Ambulatory, community-dwelling HIV seropositive individuals were recruited at six research centers. Clinical evaluations at baseline and 12 years later determined neuropathy signs and distal neuropathic pain (DNP). Additional assessments measured activities of daily living and quality of life (QOL). Factors potentially associated with DSP and DNP progression included disease severity, treatment, demographics, and co-morbidities. Adjusted odds ratios were calculated for follow-up neuropathy outcomes.

RESULTS

Of 254 participants, 21.3% were women, 57.5% were non-white. Mean baseline age was 43.5 years. Polyneuropathy prevalence increased from 25.7% to 43.7%. Of 173 participants initially pain-free, 42 (24.3%) had incident neuropathic pain. Baseline risk factors for incident pain included unemployment (OR [95% CI], 5.86 [1.97, 17.4]) and higher baseline body mass index (BMI) (1.78 [1.03, 3.19] per 10-units). Participants with neuropathic pain at follow-up had significantly worse QOL and greater dependence in activities of daily living than those who remained pain-free.

INTERPRETATION

HIV DSP and neuropathic pain increased in prevalence and severity over 12 years despite high rates of viral suppression. The high burden of neuropathy included disability and poor life quality. However, substantial numbers remained pain-free despite clear evidence of neuropathy on exam. Protective factors included being employed and having a lower BMI. Implications for clinical practice include promotion of lifestyle changes affecting reversible risk factors.

Antiretroviral therapy improves neurocognitive impairment in people living with HIV? A meta-analysis

Objectives

Although effective antiretroviral therapy (ART) has been used for more than two decades, HIV-associated neurocognitive disorder remains prevalent. Thus, whether ART can improve neurocognitive impairment is controversial. This review aims to explore the effects of ART on cognitive impairment in people living with HIV (PLWH).

Methods

A systematic literature search was conducted in eight databases (PubMed, Embase, Web of Science, Cochrane Library, CNKI, VIP, China Biology Medicine disc, and WanFang) to identify studies that compare cognitive function between study groups who are administered and not administered ART. We searched for articles published up to April 2019. Article evaluation and data extraction were independently conducted by two reviewers.

Results

Sixteen articles (6,694 participants)—14 cross-sectional studies and 2 cohort studies—were included in this meta-analysis. The cross-sectional studies demonstrated that ART group did not perform better than the non-ART group (OR = 1.16; 95% CI, 1.03–1.30). However, the cohort studies reported a significant improvement in cognitive function at three months (OR = 4.01; 95% CI, 2.35–6.85) and six months (OR = 9.24; 95% CI, 1.71–49.96) after ART initiation compared with the baseline data. No significant cognitive improvement was found in participants younger than 55 years old, but the two cross-sectional studies showed that ART may improve cognitive function in PLWH under 65 years old with poor physical condition and immune status.

Conclusions

ART could improve cognitive function in PLWH with poor physical condition and immune status, but it does not considerably improve cognition in the entire PLWH population.

New Potential Axes of HIV Neuropathogenesis with Relevance to Biomarkers and Treatment

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) affect approximately half of people living with HIV despite viral suppression with antiretroviral therapies and represent a major cause of morbidity. HAND affects activities of daily living including driving, using the Internet and, importantly, maintaining drug adherence. Whilst viral suppression with antiretroviral therapies (ART) has reduced the incidence of severe dementia, mild neurocognitive impairments continue to remain prevalent. The neuropathogenesis of HAND in the context of viral suppression remains ill-defined, but underlying neuroinflammation is likely central and driven by a combination of chronic intermittent low-level replication of whole virus or viral components, latent HIV infection, peripheral inflammation possibly from a disturbed gut microbiome or chronic cellular dysfunction in the central nervous system. HAND is optimally diagnosed by clinical assessment with imaging and neuropsychological testing, which can be difficult to perform in resource-limited settings. Thus, the identification of biomarkers of disease is a key focus of the field. In this chapter, recent advances in the pathogenesis of HAND and biomarkers that may aid its diagnosis and treatment will be discussed.

Clinical Treatment Options and Randomized Clinical Trials for Neurocognitive Complications of HIV Infection: Combination Antiretroviral Therapy, Central Nervous System Penetration Effectiveness, and Adjuvants

The etiology and pathogenesis of human immunodeficiency virus type-I (HIV)-associated neurocognitive disorders (HAND) remain undetermined and are likely the produce of multiple mechanisms. This can mainly include neuronal injury from HIV, inflammatory processes, and mental health issues. As a result, a variety of treatment options have been tested including NeuroHIV-targeted regimens based on the central nervous system (CNS) penetration effectiveness (CPE) of antiretroviral therapy (ART) and adjuvant therapies for HAND. NeuroHIV-targeted ART regimens have produced consistent and statistically significant HIV suppression in the CNS, but this is not the case for cognitive and functional domains. Most adjuvant therapies such as minocycline, memantine, and selegiline have negligible benefit in the improvement of cognitive function of people living with HIV (PLWH) with mild to moderate neurocognitive impairment. Newer experimental treatments have been proposed to target cognitive and functional symptoms of HAND as well as potential underlying pathogenesis. This review aims to provide an analytical overview of the clinical treatment options and clinical trials for HAND by focusing on NeuroHIV-targeted ART regimen development, CPE, and adjuvant therapies.

Tenofovir disoproxil fumarate induces peripheral neuropathy and alters inflammation and mitochondrial biogenesis in the brains of mice

Mounting evidence suggests that antiretroviral therapy (ART) drugs may contribute to the prevalence of HIV-associated neurological dysfunction. The HIV envelope glycoprotein (gp120) is neurotoxic and has been linked to alterations in mitochondrial function and increased inflammatory gene expression, which are common neuropathological findings in HIV+ cases on ART with neurological disorders. Tenofovir disproxil fumarate (TDF) has been shown to affect neurogenesis in brains of mice and mitochondria in neurons. In this study, we hypothesized that TDF contributes to neurotoxicity by modulating mitochondrial biogenesis and inflammatory pathways. TDF administered to wild-type (wt) and GFAP-gp120 transgenic (tg) mice caused peripheral neuropathy, as indicated by nerve conduction slowing and thermal hyperalgesia. Conversely TDF protected gp120-tg mice from cognitive dysfunction. In the brains of wt and gp120-tg mice, TDF decreased expression of mitochondrial transcription factor A (TFAM). However, double immunolabelling revealed that TFAM was reduced in neurons and increased in astroglia in the hippocampi of TDF-treated wt and gp120-tg mice. TDF also increased expression of GFAP and decreased expression of IBA1 in the wt and gp120-tg mice. TDF increased tumor necrosis factor (TNF) α in wt mice. However, TDF reduced interleukin (IL) 1β and TNFα mRNA in gp120-tg mouse brains. Primary human astroglia were exposed to increasing doses of TDF for 24 hours and then analyzed for mitochondrial alterations and inflammatory gene expression. In astroglia, TDF caused a dose-dependent increase in oxygen consumption rate, extracellular acidification rate and spare respiratory capacity, changes consistent with increased metabolism. TDF also reduced IL-1β-mediated increases in IL-1β and TNFα mRNA. These data demonstrate that TDF causes peripheral neuropathy in mice and alterations in inflammatory signaling and mitochondrial activity in the brain.

One-year stability of prospective memory symptoms and performance in aging and HIV disease

Introduction: HIV disease and aging can both affect prospective memory (PM), which describes the complex process of executing delayed intentions and plays an essential role in everyday functioning. The current study investigated the course of PM symptoms and performance over approximately one year in younger and older persons with and without HIV disease. Method: Participants included 77 older (>50 years) and 35 younger (<40 years) HIV+ individuals and 44 older and 27 younger seronegative adults. Participants completed the Memory for Intentions Test to measure PM in the laboratory, the Prospective and Retrospective Memory Questionnaire to measure PM symptoms in daily life, and several clinical measures of executive functions and retrospective memory as a part of a comprehensive neurocognitive evaluation at baseline and at 14-month follow-up. Results: Findings showed additive, independent main effects of HIV and aging on time- and event-based PM performance in the laboratory, but no change in PM over time. There were no interactions between time and HIV or age groups. Parallel findings were observed for clinical measures of retrospective memory and executive functions. Older HIV+ adults endorsed the greatest frequency of PM symptoms, but there was no change in PM symptom severity over time and no interactions between time and HIV or age groups. There were no effects of HIV or aging on naturalistic PM performance longitudinally. Conclusion: Overall these findings suggest that PM symptoms and performance in the laboratory are stably impaired over the course of a year in the setting of aging and HIV disease.

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.

Increased Prevalence of Neurocognitive Impairment in Aging People Living With Human Immunodeficiency Virus: The ANRS EP58 HAND 55–70 Study

Background

There are limited data on the comparative prevalence of neurocognitive impairment (NCI) in aging people living with human immunodeficiency virus (PLHIV) and people not living with HIV.

Methods

This was a cross-sectional study of PLHIV randomly matched by age (±4 years), gender, and education with 5 HIV-uninfected individuals from the CONSTANCES cohort. PLHIV were fluent in French and sequentially included during routine outpatient visits if aged 55–70 years, with HIV viral load &lt;50 copies/mL, and lymphocyte T-CD4 level ≥200 cells/µL in the past 24 and 12 months, respectively. The primary outcome was NCI as defined by the Frascati criteria. Multivariate normative comparison (MNC) and −1.5 standard deviations in ≥2 neurocognitive domains were secondary outcomes of NCI.

Results

Two hundred PLHIV were matched with 1000 controls. Median age was 62 years, and 85% were men. In PLHIV, the median T-CD4 lymphocyte level was 650 cells/µL, and median nadir T-CD4 lymphocyte level was 176 cells/µL. NCI was found in 71 (35.5%) PLHIV and in 242 (24.2%) controls (odds ratio [OR], 1.74; 95% confidence interval [CI], 1.25, 2.41). After adjusting for confounders, HIV remained significantly associated with NCI (OR, 1.50; 95% CI, 1.04, 2.16). Adjusted results were similar with NCI defined by MNC (ORMNC, 2.95; 95% CI, 1.13, 3.50) or −1.5 SD (OR−1.5, 2.24; 95% CI, 1.39, 3.62).

Conclusions

In this matched study of aging individuals, HIV was significantly associated with an increased risk of NCI after adjusting for major confounders. Results were confirmed with more stringent NCI classifications.

Clinical Trials Registration

NCT02592174.

Heterogeneity in neurocognitive change trajectories among people with HIV starting antiretroviral therapy in Rakai, Uganda

Considerable heterogeneity exists in patterns of neurocognitive change in people with HIV (PWH). We examined heterogeneity in neurocognitive change trajectories from HIV diagnosis to 1-2 years post-antiretroviral therapy (ART). In an observational cohort study in Rakai, Uganda, 312 PWH completed a neuropsychological (NP) test battery at two-time points (ART-naïve, 1-2 years post-ART initiation). All NP outcomes were used in a latent profile analysis to identify subgroups of PWH with similar ART-related neurocognitive change profiles. In a subset, we examined subgroup differences pre-ART on cytokine and neurodegenerative biomarkers CSF levels. We identified four ART-related change subgroups: (1) decline-only (learning, memory, fluency, processing speed, and attention measures), (2) mixed (improvements in learning and memory but declines in attention and executive function measures), (3) no-change, or (4) improvement-only (learning, memory, and attention measures). ART-related NP outcomes that are most likely to change included learning, memory, and attention. Motor function measures were unchanged. Subgroups differed on eight of 34 pre-ART biomarker levels including interleukin (IL)-1β, IL-6, IL-13, interferon-γ, macrophage inflammatory protein-1β, matrix metalloproteinase (MMP)-3, MMP-10, and platelet-derived growth factor-AA. The improvement-only and mixed subgroups showed lower levels on these markers versus the no-change subgroup. These findings provide support for the need to disentangle heterogeneity in ART-related neurocognitive changes, to focus on higher-order cognitive processes (learning, memory, attention) as they were most malleable to change, and to better understand why motor function remained unchanged despite ART treatment. Group differences in pre-ART CSF levels provide preliminary evidence of biological plausibility of neurocognitive phenotyping.

Serious Non-AIDS Conditions in HIV: Benefit of Early ART

PURPOSE OF REVIEW

Optimal control of HIV can be achieved by early diagnosis followed by the initiation of antiretroviral therapy (ART). Two large randomised trials (TEMPRANO and START) have recently been published documenting the clinical benefits to HIV-positive adults of early ART initiation. Main findings are reviewed with a focus on serious non-AIDS (SNA) conditions.

RECENT FINDINGS

Data from the two trials demonstrated that initiating ART early in the course of HIV infection resulted in marked reductions in the risk of opportunistic diseases and invasive bacterial infections. This indicates that HIV causes immune impairment in early infection that is remedied by controlling viral replication. Intriguingly, in START, a marked reduction in risk of cancers, both infection-related and unrelated types of cancers, was observed. Like the findings for opportunistic infections, this anti-cancer effect of early ART shows how the immune system influences important pro-oncogenic processes. In START, there was also some evidence suggesting that early ART initiation preserved kidney function, although the clinical consequence of this remains unclear. Conversely, while no adverse effects were evident, the trials did not demonstrate a clear effect on metabolic-related disease outcomes, pulmonary disease, or neurocognitive function. HIV causes immune impairment soon after acquisition of infection. ART reverses this harm at least partially. The biological nature of the immune impairment needs further elucidation, as well as mechanisms and clinical impact of innate immune activation. Based on the findings from TEMPRANO and START, and because ART lowers the risk of onward transmission, ART initiation should be offered to all persons following their diagnosis of HIV.

Association between cognitive reserve and cognitive performance in people with HIV: a systematic review and meta-analysis

Cognitive reserve is a potential explanation for the disparity between brain pathology and its clinical manifestations. The main objective of this study was to estimate, based on published studies, the strength of the association between cognitive reserve and cognitive performance in individuals with HIV. A systematic literature search using Ovid MEDLINE, PsychINFO, and EMBASE was performed to identify studies published between 1990 and 2016 that quantified the association between cognitive reserve and cognitive performance in HIV. A random-effects meta-analysis was used to compute a summary estimate (Cohen's d) with 95% confidence intervals (CI) and 95% prediction intervals (PI). The risk of bias and quality of reporting in the studies were indicated by the Appraisal tool for Cross-Sectional Studies (AXIS). Ten observational studies were deemed eligible. The pooled effect size was 0.9 (95% CI: 0.7-1.0; 95% PI: 0.4-1.4) with marked heterogeneity studies [Cochran's Q (df = 9) = 28.0, p = .0009; I² statistic = 67.4%]. Risk-of-bias appraisal showed that non-response bias was never addressed and the items associated with selection bias were only partially met. The association between cognitive reserve and cognitive performance suggests that building reserve through non-pharmacological interventions could be a potentially effective way of combating cognitive impairment in people with HIV.

Cognitive screening in treatment-naïve HIV-infected individuals in Hong Kong - a single center study

Background

HIV-associated neurocognitive disorder (HAND) remains prevalent in the era of combination antiretroviral therapy (cART). The prevalence of HAND in Hong Kong is not known.

Methods

Between 2013 and 2015, 98 treatment-naïve HIV-1-infected individuals were referred to and screened by the AIDS Clinical Service, Queen Elizabeth Hospital with (1) the International HIV Dementia Scale (IHDS), a screening tool that targets moderate to severe HAND, (2) the Montreal Cognitive Assessment (MoCA), a frequently used cognitive screening test and (3) the Patient Health Questionnare-9 (PHQ-9), a 9-item questionnaire that evaluates depression symptoms. Within the study period, 57 of them completed the second set of IHDS and MoCA at 6 months after baseline assessment.

Results

Most participants were male (94%), with a median age of 31 years. At baseline, 38 (39%) and 25 (26%) of them scored below the IHDS (≤10) and MoCA (25/26) cut-offs respectively. Poor IHDS performers also scored lower on MoCA (p = 0.039) but the correlation between IHDS and MoCA performance was weak (r = 0.29, p = 0.004). Up to a third of poor IHDS performers (13/38) showed moderate depression (PHQ-9 > 9). In the multivariable analysis, a lower education level (p = 0.088), a history of prior psychiatric illness (p = 0.091) and the presence of moderate depression (p = 0.079) tended to be significantly associated with poor IHDS performance.

At follow-up, 54 out of 57 were on cART, of which 46 (85%) had achieved viral suppression. Their blood CD4+ T-lymphocytes and IHDS scores were higher at follow-up compared to baseline values (both p < 0.001) but their MoCA performance was similar at both assessments. Of note, 17 participants in this subgroup scored below the IHDS cut-off at both assessments.

Conclusions

Poor IHDS performance, and likely cognitive impairment, was frequently observed in treatment-naïve HIV-infected individuals in our locality. A considerable proportion continued to score below the IHDS cut-off at 6 months after cART. Depression was frequently observed in this vulnerable population and was associated with poor IHDS performance.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3784-y) contains supplementary material, which is available to authorized users.

EEG-Based Neurocognitive Metrics May Predict Simulated and On-Road Driving Performance in Older Drivers

The number of older drivers is steadily increasing, and advancing age is associated with a high rate of automobile crashes and fatalities. This can be attributed to a combination of factors including decline in sensory, motor, and cognitive functions due to natural aging or neurodegenerative diseases such as HIV-Associated Neurocognitive Disorder (HAND). Current clinical assessment methods only modestly predict impaired driving. Thus, there is a need for inexpensive and scalable tools to predict on-road driving performance. In this study EEG was acquired from 39 HIV+ patients and 63 healthy participants (HP) during: 3-Choice-Vigilance Task (3CVT), a 30-min driving simulator session, and a 12-mile on-road driving evaluation. Based on driving performance, a designation of Good/Poor (simulator) and Safe/Unsafe (on-road drive) was assigned to each participant. Event-related potentials (ERPs) obtained during 3CVT showed increased amplitude of the P200 component was associated with bad driving performance both during the on-road and simulated drive. This P200 effect was consistent across the HP and HIV+ groups, particularly over the left frontal-central region. Decreased amplitude of the late positive potential (LPP) during 3CVT, particularly over the left frontal regions, was associated with bad driving performance in the simulator. These EEG ERP metrics were shown to be associated with driving performance across participants independent of HIV status. During the on-road evaluation, Unsafe drivers exhibited higher EEG alpha power compared to Safe drivers. The results of this study are 2-fold. First, they demonstrate that high-quality EEG can be inexpensively and easily acquired during simulated and on-road driving assessments. Secondly, EEG metrics acquired during a sustained attention task (3CVT) are associated with driving performance, and these metrics could potentially be used to assess whether an individual has the cognitive skills necessary for safe driving.

Effects of HIV on executive function and verbal fluency in Cameroon

HIV-associated neurocognitive disorders (HAND) are frequently associated with impaired executive function and verbal fluency. Given limited knowledge concerning HAND in Sub-Saharan-Africa and lack of Cameroonian adult neuropsychological (NP) test norms, we administered four executive function [Halstead Category Test (HCT), Wisconsin Card Sorting Test (WCST), Color Trails-II (CTT2), and Stroop Color-Word-Interference (SCWT)] and three verbal fluency (Category, Action, and Letter Fluency) tests to 742 adult Cameroonians (395 HIV-, 347 HIV+). We developed demographically-corrected NP test norms and examined the effects of HIV and related variables on subjects' executive function and verbal fluency. HIV+ subjects had significantly lower T-scores on CTT2 (P = 0.005), HCT (P = 0.032), WCST (P < 0.001); lower executive function composite (P = 0.002) and Action Fluency (P = 0.03) T-scores. ART, viremia, and CD4 counts did not affect T-scores. Compared to cases harboring other viral subtypes, subjects harboring HIV-1 CRF02_AG had marginally higher CTT2 T-scores, significantly higher SCWT (P = 0.015) and executive function (P = 0.018) T-scores. Thus, HIV-1 infection in Cameroon is associated with impaired executive function and some aspects of verbal fluency, and viral genotype influenced executive function. We report the first normative data for assessing executive function and verbal fluency in adult Cameroonians and provide regression-based formulas for computing demographically-adjusted T-scores. These norms will be useful for investigating HIV/AIDS and other diseases affecting cognitive functioning in Cameroon.

Empiric neurocognitive performance profile discovery and interpretation in HIV infection

The measurement and determinants of HIV-associated neurocognitive disorders (HAND) are under intense debate. We used latent profile analysis (LPA) and machine learning to define neurocognitive performance profiles and identify their associated risk factors in HIV patients receiving antiretroviral therapy (ART). Neurocognitive performance was assessed by a multidomain neuropsychological test battery. LPA was used to define individual neurocognitive profiles. Random forest analyses (RFA) identified the most important factors distinguishing each profile. Three profiles emerged from the LPA: profile 1 (P1, n = 159) achieved the highest performance, while profile 2 (P2, n = 163) had lowered executive functions and verbal memory, and profile 3 (P3, n = 59) was globally impaired. RFA achieved good prediction (area under the curve ≥ 0.80) only for global impairment (P3). Non-North American descent was the dominant predictor of P3, followed by factors coinciding with non-North American descent (female sex and toxoplasma seropositivity). Additional predictors included unemployment, current depressive symptoms, lower nadir CD4, and longstanding HIV. Restricting analyses to North Americans pointed to the additional importance of ART achieving high CSF levels and older age in prediction of P3. HAND diagnoses were most common in the globally impaired profile (P3 = 89.8%), followed by the group with reduced higher-order neurocognitive performance (P2 = 16.6%). Thus, implementation of LPA and RFA empirically distinguished three distinct neurocognitive performance profiles in this HIV-infected cohort while also highlighting potential risk factors and their relative importance to neurocognitive impairment. These data-driven analytical methods pointed to discernible demographic, HIV- and treatment-related risk factor constellations in patients born outside and within North America that might influence diagnostic and therapeutic decisions.

Neurofilament light chain in blood is negatively associated with neuropsychological performance in HIV-infected adults and declines with initiation of antiretroviral therapy

HIV-associated neurocognitive disorder (HAND) persists in the combination antiretroviral therapy (cART) era and is associated with diminished quality of life. The disorder remains challenging to diagnose given the requirement for comprehensive neuropsychological testing. Blood biomarkers are needed to facilitate the diagnosis of HAND and to gauge neurological response to antiretroviral therapy. We performed a study of plasma neurofilament light chain (NFL) that included 37 HIV-infected and 54 HIV-negative adults. In the univariate mixed-effect model involving HIV-infected participants, there was a statistically significant linear relationship between composite neuropsychological score (NPT-11) and plasma NFL (slope = - 9.9, standard error = 3.0 with 95% confidence interval - 3.2 to - 16.6 and p = 0.008 when testing slope = 0). Similarly, in the multivariate mixed-effect model, higher plasma NFL was significantly associated with worse NPT-11 (slope = - 11.5, standard error = 3.3 with 95% confidence interval - 3.7 to - 19.0 and p = 0.01 when testing slope = 0). The association between NPT-11 and NFL appeared to be driven by the group of individuals off cART. In a subset of participants who had visits before and after 24 weeks on cART (n = 11), plasma NFL declined over time (median = 22.7 versus 13.4 pg/ml, p = 0.02). In contrast, plasma NFL tended to increase over time among HIV-negative participants (median 10.3 versus 12.6 pg/ml, p = 0.065, n = 54). Plasma NFL therefore shows promise as a marker of neuropsychological performance during HIV. Larger studies are needed to determine if NFL could serve as a diagnostic tool for HAND during suppressive cART.

The relationship between cognitive change and physical health and behavioural outcomes in a Ugandan cohort of adults living with HIV - a longitudinal study

We investigated changes in cognitive function and physical health and behavioural outcomes (HIV disease progression, health-seeking behaviour, adherence to HIV medications and risky sexual behaviour) at baseline and 12 months later among 1126 Ugandan adults living with HIV. Overall, cognitive function improved from baseline to follow-up, except for gait speed, which was slower at follow-up compared to baseline. There were improvements in physical health and behavioural outcomes by follow-up, with greater improvements among individuals on ART compared to those not on ART. Change in gait speed over time significantly predicted risky sexual behaviours at follow-up. This is the first study to investigate the longitudinal relationships between cognitive function and health outcomes among Ugandan adults living with HIV and provide insights into the possible links between cognitive function and negative clinical and behavioural health outcomes in people living with HIV.

HIV-1-Associated Neurocognitive Disorders: Is HLA-C Binding Stability to β2-Microglobulin a Missing Piece of the Pathogenetic Puzzle?

AIDS dementia complex (ADC) and HIV-associated neurocognitive disorders (HAND) are complications of HIV-1 infection. Viral infections are risk factors for the development of neurodegenerative disorders. Aging is associated with low-grade inflammation in the brain, i.e., the inflammaging. The molecular mechanisms linking immunosenescence, inflammaging and the pathogenesis of neurodegenerative disorders, such as Alzheimer's disease (AD) and Parkinson's disease, are largely unknown. ADC and HAND share some pathological features with AD and may offer some hints on the relationship between viral infections, neuroinflammation, and neurodegeneration. β2-microglobulin (β2m) is an important pro-aging factor that interferes with neurogenesis and worsens cognitive functions. Several studies published in the 80-90s reported high levels of β2m in the cerebrospinal fluid of patients with ADC. High levels of β2m have also been detected in AD. Inflammatory diseases in elderly people are associated with polymorphisms of the MHC-I locus encoding HLA molecules that, by associating with β2m, contribute to cellular immunity. We recently reported that HLA-C, no longer associated with β2m, is incorporated into HIV-1 virions, determining an increase in viral infectivity. We also documented the presence of HLA-C variants more or less stably linked to β2m. These observations led us to hypothesize that some variants of HLA-C, in the presence of viral infections, could determine a greater release and accumulation of β2m, which in turn, may be involved in triggering and/or sustaining neuroinflammation. ADC is the most severe form of HAND. To explore the role of HLA-C in ADC pathogenesis, we analyzed the frequency of HLA-C variants with unstable binding to β2m in a group of patients with ADC. We found a higher frequency of unstable HLA-C alleles in ADC patients, and none of them was harboring stable HLA-C alleles in homozygosis. Our data suggest that the role of HLA-C variants in ADC/HAND pathogenesis deserves further studies. If confirmed in a larger number of samples, this finding may have practical implication for a personalized medicine approach and for developing new therapies to prevent HAND. The exploration of HLA-C variants as risk factors for AD and other neurodegenerative disorders may be a promising field of study.

Comparison of two screening tests for HIV-Associated Neurocognitive Disorder suspected Japanese patients with respect to cART usage

In this study, we demonstrated the pervasiveness of HIV-associated neurocognitive disorders (HAND) among a selection of Japanese patients as well as evaluated and compared the Mini Mental State Examination (MMSE) and the International HIV Dementia Scale (IHDS) for use as a screening tool among combination anti-retroviral therapy (cART)-naïve and cART experienced patients. The MMSE and the IHDS have both been used as HAND screening tests around the world with variable success. It has been reported the increased usage of cART the utility of these screening tests may have been diminished due to the decreased severity of impairment and the altered pattern of neurocognitive impairments in cART era HAND patients. It is therefore possible the MMSE and the IHDS may still be useful among cART-naïve patients even in the cART era. However, only one study has investigated and compared the screening results of the IHDS among cART-naïve and cART experienced patients. All HIV positive patients who visited, or were admitted, to the Ryukyu University Hospital between January 2009 and March 2014 were evaluated for inclusion. Selected patients (n = 49) had data without omission for all tests. The overall prevalence of HAND in our cohort was 44%. The area under the curve (AUC), for all subjects using the MMSE and the IHDS, were 0.60 and 0.69, respectively. However, the AUC among cART-naïve patients were 0.58 and 0.76 for the MMSE and the IHDS, respectively. Whereas, cART experienced patients had an AUC of 0.60 and 0.61, respectively. Overall, the MMSE demonstrated a poor screening ability for HAND, regardless of cART usage (the cut-off value of 27 had a Youden's J-Index of 0.1, in all groups). Alternatively, the IHDS was moderately useful for HAND screening among cART-naïve patients (the cut-off value of 11 had a Youden's J-Index of 0.4), but performed poorly as a screening test among cART experienced patients (the cut-off value of 11 had a Youden's J-Index of 0.1).

Changes in cerebral function parameters with maraviroc-intensified antiretroviral therapy in treatment naive HIV-positive individuals

BACKGROUND

Maraviroc-intensified antiretroviral therapy (ART) may be associated with cognitive benefits.

METHODS

Therapy-naive, cognitively asymptomatic, HIV-positive individuals were randomly allocated on a 1 : 1 basis to standard ART (Arm1: tenofovir-emtricitabine and atazanavir/ritonavir) or maraviroc intensified ART (Arm2: abacavir-lamivudine and darunavir/ritonavir/maraviroc). Over 48 weeks, detailed assessments of cognitive function tests were undertaken and cerebral metabolites measured using proton magnetic resonance spectroscopy. Our primary endpoint was mean change in cognitive function across treatment arms with factors associated with cognitive function changes also assessed.

RESULTS

Of 60 individuals randomized (30 Arm1 and 30 Arm2), 58 were men and 44 of white ethnicity. Treatment groups had similar disease characteristics including overall mean (SD) baseline CD4 cell count 428 (209) and 414 (229) cells/μl, Arms1 and 2, respectively. At week 48, plasma HIV RNA was less than 50 copies/ml in 55 of 56 of those completing study procedures. Cognitive function improved over 48 weeks [mean change z-score (SD) 0.16 (0.09) Arm1 and 0.25 (0.08) Arm2, P = 0.96 for differences between study arms]. A greater increase in frontal grey matter N-acetyl aspartate/creatine ratio was observed in Arm1 [ratio change of 0.071 (SD 0.16)] versus Arm2 [change -0.097 (SD 0.18), P = 0.009], although this was not associated with changes in cognitive function (P = 0.17).

CONCLUSION

Maraviroc-intensified ART had no demonstrable benefit on cognitive function in individuals initiating ART. Greater improvement in neuronal metabolites (N-acetyl aspartate/creatine) was observed with standard ART. Future work should focus on maraviroc-intensified ART in individuals with cognitive impairment.

No neurocognitive advantage for immediate antiretroviral treatment in adults with greater than 500 CD4+ T-cell counts

OBJECTIVE

To compare the effect of immediate versus deferred antiretroviral treatment (ART) on neuropsychological test performance in treatment-naive HIV-positive adults with more than 500 CD4 cells/μl.

DESIGN

Randomized trial.

METHODS

The START parent study randomized participants to commence immediate versus deferred ART until CD4 less than 350 cells/μl. The START Neurology substudy used eight neuropsychological tests, at baseline, months 4, 8, 12 and annually, to compare groups for changes in test performance. Test results were internally standardized to z-scores. The primary outcome was the average of the eight test z-scores (QNPZ-8). Mean changes in QNPZ-8 from baseline were compared by intent-to-treat using longitudinal mixed models. Changes from baseline to specific time points were compared using ANCOVA models.

RESULTS

The 592 participants had a median age of 34 years; median baseline CD4 count was 629 cells/μl; the mean follow-up was 3.4 years. ART was used for 94 and 32% of accrued person-years in the immediate and deferred groups, respectively. There was no difference between the immediate and deferred ART groups in QNPZ-8 change through follow-up [-0.018 (95% CI -0.062 to 0.027, P = 0.44)], or at any visit. However, QNPZ-8 scores increased in both arms during the first year, by 0.22 and 0.24, respectively (P < 0.001 for increase from baseline).

CONCLUSION

We observed substantial improvement in neurocognitive test performance during the first year in both study arms, underlining the importance of using a control group in studies assessing neurocognitive performance over time. Immediate ART neither benefitted nor harmed neurocognitive performance in individuals with CD4 cell counts above 500 cells/μl.

Development and validation of an LC-MS/MS assay for tenofovir and tenofovir alafenamide in human plasma and cerebrospinal fluid

A liquid chromatography with triple quadrupole mass spectrometry method was developed and validated for the determination of tenofovir and tenofovir alafenamide concentrations in human plasma and cerebrospinal fluid. Tenofovir and tenofovir alafenamide were extracted from matrix by solid phase extraction. The dried extraction eluents were dissolved in water for LC-MS/MS analysis. Separation was achieved with a Phenomenex Synergi 4 μm Polar-RP 80A column (50 × 2 mm) with a gradient elution of 0.1% formic acid in water and acetonitrile. The total run time was 5 min. Detection of analytes was achieved using electrospray ionization (positive mode) and triple quadrupole selected reaction monitoring. Standard curve concentrations ranged from 0.5 to 500 ng/mL for the plasma assay and 0.1-50 ng/mL for the cerebrospinal fluid assay. The intra- and inter-day accuracy and precision were less than 12% in low, medium, and high quality control samples for both matrices. The validated methods were applied to the analysis of plasma and cerebrospinal fluid samples of a patient undergoing tenofovir therapy which involved the switch from Stribild^® (elvitegravir 150 mg/cobicistat 150 mg/emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg) to Genvoya^® (elvitegravir 150 mg/cobicistat 150 mg/emtricitabine 200 mg/tenofovir alafenamide 10 mg).

Voices from Australia- concerns about HIV associated neurocognitive disorder

This study aimed to determine whether people living with HIV (PLHIV) are concerned about HIV associated neurocognitive disorder (HAND) and would find information and resources for HAND beneficial. An online survey focusing on the experience of HAND was distributed via the website of Positive Life New South Wales: a peak peer-support non-government organization in Australia. Of 126 respondents, 94 (74%) had heard of HAND, 52/94 (55%) had experienced concerns and of these, 48/52 (92%) felt anxiety about discussing the subject. Of those who had experienced concerns, 30/52 (58%) had spoken to someone about these concerns and 23/30 (77%) had received a positive response. Across the entire sample, 74 (59%) had noticed symptoms of cognitive decline in themselves and/or others. Respondents who noted a decrease in their ability to organize were on average five years older than those who had not noticed a decline (p = 0.012, effect size -.54). Forty-nine (39%) indicated that they would like guidance to initiate discussion about HAND with their doctor, caregiver or other PLHIV. The survey findings suggest that increasing awareness of HAND among PLHIV and their caregivers, and providing resources to facilitate discussion about HAND may assist to reduce concerns among PLHIV and enhance the effectiveness of clinical review.

A study of neuropsychological profile of human immunodeficiency virus-positive children and adolescents on antiretroviral therapy

AIMS

The aim is to study the neuropsychological and functional profile of children and adolescents with human immunodeficiency virus (HIV) infection on antiretroviral therapy (ART) and the association between the neuropsychological status and medical illness variables, treatment variables, and functional status in the cases of the sample and compare with normal controls.

MATERIALS AND METHODS

Forty-two HIV-positive children and adolescents on ART were evaluated and compared with 40 matched controls not known to be HIV-positive. The tools used were the Wechsler Intelligence Scale for Children-III R for neuropsychological evaluation, the Brief Impairment Scale to assess functional impairment, and a semi-structured questionnaire to obtain other relevant details.

RESULTS

There were significant differences between the verbal, performance intelligence quotients (IQs), global IQ score, and several individual subtests between cases and controls. The HIV group was also found to have a significant functional impairment.

CONCLUSION

Our findings show that HIV infection is associated with significant cognitive and functional impairment. The role of ART in these impairments requires further study. Such understanding can help to introduce wholesome and relatively safer management strategies for youngsters with HIV infection and improve their quality of life.