Updated research nosology for HIV-associated neurocognitive disorders

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

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

Predicting Trajectories of Everyday Functioning in Adults Aging with HIV Using Latent Growth Mixture Modeling

As the U.S. population of people with HIV (PWH) ages, PWH exhibit high rates of adverse health outcomes including everyday functioning decline. We aimed to (1) identify trajectories of self-reported everyday functioning and (2) examine baseline predictors (demographics, cognitive domains, psychiatric and medical comorbidities, HIV-disease characteristics) of trajectories among PWH. 742 PWH completed up to five semi-annual visits over two years. Latent growth mixture modeling identified a linear 3-class solution with good statistical fit and interpretability. Most PWH (88%) had good baseline functioning with stability. Two classes had elevated baseline functional declines with worsening (7%) or improvement (5%). Greater depressive symptoms and motor skills impairment predicted higher odds of impaired functioning. Having chronic pulmonary disease increased odds of improvement, which may reflect connection to care, while older age increased odds of worsening. Most aging PWH demonstrate stable everyday functioning; however, interventions for depression and motor skills may improve functioning.

Diagnosis of Learning Disabilities but not Academic Difficulties Alone is Associated with Neurocognitive Impairment in People Living with HIV: Evidence from Clinical Research to Support and Refine the Current HAND Diagnostic Guidelines

Diagnosing HIV-associated neurocognitive disorder (HAND) is a complex process aimed at determining the role of HIV versus other causes of neurocognitive impairment. In treated people with living long-term HIV infection, this process is further complicated by the presence of multiple medical and psychiatric comorbidities and varied educational history. Evidence-based research is therefore needed to refine the 2007 HAND diagnostic criteria on how to consider multimorbidity in making differential diagnoses. This is the case for presence of academic difficulties versus diagnosis of learning disabilities (LD), which have not been systematically studied in relation to HAND, and especially in relation to the presence of cognitive and depressive symptoms. The current study included 903 people with HIV referred for a comprehensive neuropsychological assessment of HAND at the Neurobehavioural Clinical-Research Unit (St. Michael's Hospital in Toronto, ON, Canada). Pre-morbid ability was assessed prior to standard testing and participants were classified into LD groups: No learning disabilities (n = 474), academic difficulties (n = 352) or diagnosed learning disability (LD, n = 77). The neuropsychological test battery assessed domains of complex attention, learning and memory, psychomotor efficiency, and executive functioning, and performance was adjusted with demographic corrections. Neurocognitive impairment (NCI) status was determined using the global deficit score method (GDS ≥ 0.5 detecting at least mild global NCI). Depressive symptoms were assessed with the Beck Depression Inventory (BDI), and cognitive symptoms with the Patient's Assessment of Own Functioning (PAOFI). Logistic regression models were used to assess odds of NCI in the three groups while considering main and interactive effects of clinically relevant depression (BDI > 10) or elevated cognitive symptoms (PAOFI > 3). Only LD diagnosis was significantly associated with increased odds of NCI, OR = 1.90, 95% CI (1.15, 3.14). In the same model, both cognitive symptoms, OR = 1.97, 95% CI (1.50, 2.58), and depression symptoms OR = 1.39, 95% CI (1.06, 1.82) were also significantly associated with increased odds of NCI, but not their interaction. Diagnosis of LD, but not academic difficulties alone, is associated with increased odds of NCI among treated persons living with HIV who are clinically referred. While this was in part independent of depression and cognitive symptoms, adults with HIV and LD diagnosis who had high depression and cognitive symptoms had greatest odds of NCI. These findings assist in the refinement of the current HAND diagnostic guidelines.

Cognitive impairment in persons with HIV: changing aetiologies and management strategies

PURPOSE OF REVIEW

Cognitive disorders have been described in persons with HIV since the advent of virologically suppressive antiretroviral therapy. As persons with HIV age, their demographics and risk factors for cognitive health have changed. Here, we review these changing demographics and the recent literature regarding risk factors for cognitive decline and best management strategies.

RECENT FINDINGS

Rates on noninfectious comorbidities are higher in persons with HIV compared to those without HIV and specifically include high rates of mental health conditions and cardiovascular complications. The optimal management of these noninfectious comorbidities is crucial for maintaining brain health. The early initiation of antiretroviral therapy may prevent irreversible damage to brain health and modern integrase-strand-transfer-inhibitor based antiretroviral regimens appear to have a positive effect on cognitive health.

SUMMARY

Risk factors for cognitive decline in persons with HIV have dramatically changed in recent years along with clinical management strategies. As persons with HIV globally continue to age, ongoing considerations of these risk factors and management strategies will continue to be key in maintaining brain health for the 40 million people living with HIV globally.

Characteristics of cortical thickness in treated HIV-infected individuals with and without cognitive impairment

BACKGROUND

HIV can alter the brain structure and function in the early stage of infection. This study investigated the differences in cortical thickness patterns between healthy controls (HCs) and people living with HIV (PLWH) with asymptomatic neurocognitive impairment (ANI) or cognitive integrity (CI).

METHODS

Twenty-one ANI, 25 CI, and 24 HCs were recruited and underwent high-resolution T1-weighted magnetic resonance images. Cortical thickness was analyzed using the Computational Anatomy Toolbox, and the correlation analysis was conducted between cortical thickness and clinical and neuropsychological variables.

RESULTS

Both CI and ANI exhibited decreased cortical thickness, primarily in the left frontal cortices and bilateral limbic system. ANI demonstrated a more pronounced and widespread pattern of cortical thinning. Lower CD4+ counts and higher peak plasma viral load were associated with decreased cortical thickness of the right pericallosal sulcus and middle-posterior part of cingulate gyrus and sulcus in ANI. Conversely, compared to HCs, both ANI and CI showed cortical thickening in the left insula cortex, and ANI tended to have a thicker cortex. Moreover, the increased thickness of left insula cortex in both CI and ANI were positively correlated with attention and working memory.

CONCLUSIONS

The cortical thickness thinning was observed in the frontal and limbic systems in both ANI and CI. Meanwhile, the thickening of the insular cortex may represent mild neuroinflammation or a transient compensatory mechanism. This study provides new insights into the neural mechanisms underlying HIV-related cognitive impairment and highlights the importance of cortical thickness alteration patterns when assessing cognitive function of PLWH.

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

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

Assessing Glymphatic Function, Global Brain Activity, and Cognitive Performance in Adolescents Living With Perinatal HIV Exposure

The discovery of the glymphatic system has provided a theoretical framework for understanding neurofluid dynamics and waste clearance within the brain. Recent studies suggest that the function of the glymphatic system is also reflected in the resting-state spontaneous brain activity. However, whether and how these functions change in perinatally HIV-infected (PHIV) adolescents, a population characterized by neuroviral infection and antiviral treatment, is largely unknown. This study aims to investigate whether PHIV-exposed infected and uninfected adolescents exhibit changes in glymphatic function and spontaneous brain activity that differ from their healthy, typically developing peers, and if these changes are associated with pathways involving related gene and receptor expression. Sixteen adolescents with perinatally acquired HIV infection (HIV+), 18 perinatally HIV-exposed but uninfected adolescents (HEU), and 30 demographically matched typically developing (TD) adolescents were enrolled. Cognitive, clinical, structural, and functional MRI data were collected. Diffusion tensor imaging along the perivascular space (DTI-ALPS) was employed to characterize glymphatic function, and whole-brain functional connectivity based on resting-state fMRI was used to investigate the diffusion of global oscillatory signals. Further mediation analysis was conducted to delineate the interactive relationships among DTI-ALPS, whole-brain signal dynamics, and cognitive assessments. HIV+ and HEU adolescents exhibited comparable DTI-ALPS scores (p > 0.05), yet both groups showed significantly higher DTI-ALPS compared with TD peers (p < 0.05). These findings suggest that not only perinatal HIV infection but also perinatal HIV exposure significantly and profoundly impacts subsequent adolescent brain glymphatic function and whole-brain signal dynamics.

External versus internal focus enhances motor performance and learning in children with different visuospatial working memory capacities

Research has shown that external focus (EF) instructions-directing attention to intended movement effects (e.g., ball's or dart's path)-are more effective for enhancing motor performance and learning than internal focus (IF) instructions, which focus on body movements (e.g., arm or foot motion). Nonetheless, the impact of visuospatial working memory capacity (WMC) in this context, especially among children, has been less investigated. This research sought to examine the effects of EF compared to IF on the skill acquisition and motor learning of a dart-throwing task among children with both high and low visuospatial WMC. Forty-eight boys aged 9-11 (Mage: 9.67 ± 0.76 years) were grouped by high or low WMC based on spatial span and memory tests, then assigned to receive either EF or IF instructions. The experiment comprised three stages: practice, retention, and two transfer tests, including throwing from a longer distance and a dual-task scenario with added cognitive load (tone counting). Results showed that EF outperformed IF at all stages. While WMC did not affect performance during practice and retention, children with low WMC performed better than those with high WMC during the longer distance test. In dual-task conditions, an EF continued to surpass an IF, whilst the WMC exerted no significant impact. The present findings suggest that an EF relative to an IF promotes more automatic movement and enhanced multitasking, while the impact of visuospatial WMC was less than expected, highlighting the benefits of EF in teaching motor skills to children, regardless of visuospatial WMC.

Functional and Structural Network Alterations in HIV-Associated Asymptomatic Neurocognitive Disorders: Evidence for Functional Disruptions Preceding Structural Changes

Purpose

This study focuses on the asymptomatic neurocognitive impairment (ANI) stage of HIV-associated neurocognitive disorders (HAND). Using multimodal MRI and large-scale brain network analysis, we aimed to investigate alterations in functional networks, structural networks, and functional-structural coupling in persons with ANI.

Patients and Methods

A total of 95 participants, including 48 healthy controls and 47 persons with HIV-ANI, were enrolled. Resting-state fMRI and diffusion tensor imaging were used to construct functional and structural connectivity matrices. Graph-theoretical analysis was employed to assess inter-group differences in global metrics, nodal characteristics, and functional-structural coupling patterns. Furthermore, machine learning classifiers were used to construct and evaluate classification models based on imaging features from both groups. The performance of different models was compared to identify the optimal diagnostic model for detecting HIV-ANI.

Results

Structural network analysis showed no significant changes in the global or local topological properties of persons with ANI. In contrast, functional networks exhibited significant reorganization in key regions, including the visual, executive control, and default mode networks. Functional-structural coupling was significantly enhanced in the occipital and frontal networks. These changes correlated with immune status, infection duration, and cognitive performance. Furthermore, the classification model integrating graph-theoretical topological features and functional connectivity achieved the best performance, with an area under the curve (AUC) of 0.962 in the test set.

Conclusion

Functional network reorganization and enhanced functional-structural coupling may reflect early synaptic and dendritic damage in persons with ANI, serving as potential early warning signals for HAND progression. These findings provide sensitive biomarkers and valuable perspectives for early diagnosis and intervention.

Predicting Neurobehavioral Outcomes in People with HIV

We aimed to identify complex, multidimensional, longitudinal biopsychosocial phenotypes (MLBPSPs) in people with HIV (PWH) and evaluate their associations with baseline clinical characteristics. We included 506 PWH in the multi-site CHARTER study who underwent assessments at four visits, six months apart. Using machine learning, we identified four MLBPSP clusters based on means and nonlinear trajectories of biopsychosocial characteristics. These characteristics included neurocognition, depressed mood, self-reported cognitive symptoms, and activities of daily living at each visit. The largest MLBPSP cluster (C1, N = 231) had the best average scores across all domains and remained stable over 18 months of follow-up. Other clusters showed varying degrees of cognitive impairment, depressed mood, and functional disability. In multivariable analyses, several baseline clinical characteristics, including chronic pulmonary disease, distal neuropathic pain, polypharmacy, and creatinine levels, significantly predicted one or more adverse MLBPSP trajectories. These findings have implications for HIV care by identifying PWH at risk for future adverse trajectories. The results may lead to insights informing future personalized interventions targeted to vulnerable subpopulations of PWH.

Graph theory analysis reveals functional brain network alterations in HIV-associated asymptomatic neurocognitive impairment in virally suppressed homosexual males

BACKGROUND

This study aimed to investigate the global and nodal functional network alterations, abnormal connections of brain regions, and potential imaging biomarkers in virally suppressed people living with HIV (PLH) with asymptomatic neurocognitive impairment (ANI) using graph theory analysis.

METHODS

The study included 64 men with ANI (mean age 32.45 years) and 64 healthy controls (HC) (mean age 31.31 years). The functional network was established through the graph theory method and Automated Anatomic Labeling (AAL) 90 atlas, which provides a cerebrum parcellation framework. Moreover, hub regions were identified based on betweenness centrality (Bc). Functional connectivity (FC) differences were investigated between the two groups, these connections were located in the resting-state network (RSN). Neuropsychological (NP) tests were performed, and relationships between graph theory measures, clinical data, and NP tests were analyzed. Multiple comparisons were used to correct for false-positive findings.

RESULTS

On the global level, small-worldness, global efficiency (Eg), and local efficiency (Eloc) were significantly decreased in ANI subjects. On a nodal level, brain regions in the frontal and subcortical regions showed significantly decreased nodal measures, while regions in the parietal, temporal, and occipital lobes showed increased nodal measures. Increased FCs were found between brain regions in the visual, frontoparietal, and somatomotor networks. Hub regions overlapped highly between the two groups. Age was negatively correlated with graph theory measures.

CONCLUSION

Our findings demonstrate the global and nodal alterations in the functional network of virally suppressed homosexual males in the ANI stage. Frontal and subcortical brain regions may be important for finding the imaging biomarkers for HIV-associated neurocognitive disorder.

Cerebrospinal fluid biomarkers associated with neurofilament light levels: A study in HIV disease

BACKGROUND

A retrospective study was conducted in people with HIV (PWH) to explore potential cerebrospinal fluid (CSF) biomarkers linked to CSF neurofilament light levels (NfL), indicative of neuronal injury.

METHODS

A sample of 168 participants was tested, including 43 HIV-negative controls and PWH who were classified into subgroups based on HIV and treatment status. Twenty CSF protein biomarkers were analyzed for their association with CSF NfL concentrations using a linear regression forward selection strategy, adjusted for age and sex. Regression trees were utilized to visualize feature relationships.

RESULTS

Age-adjusted average concentrations of CSF NfL ranged from 427 pg/mL (SD = 190) in HIV- participants to 6456 pg/mL (SD = 46,024) in participants with HIV-associated dementia. Significant associations were found between specific biomarkers and CSF NfL levels in different participant subgroups. Noteworthy findings included correlations between CSF t-tau, CSF MCP-1, CSF TNF-α, and albumin ratio with CSF NfL levels in untreated PWH, and CSF IL-21 with CSF NfL in treated, virally suppressed PWH. Association between age and CSF NfL concentrations was a general finding.

CONCLUSION

We identified specific CSF biomarkers, including CSF t-tau protein, CSF MCP-1, and CSF TNF-α that associated with CSF NfL concentrations in untreated PWH and CSF IL-21 that associated with CSF NfL in PWH with effective treatment, shedding light on neuroinflammatory processes which may underlie HIV-related neuronal injury and the impact of antiviral therapy. Further investigations are needed to validate if elevated CSF IL-21 concentrations persist during long-term treatment, and if particular drug combinations are optimal for decreasing inflammatory latency.

Psychosocial factors account for a proportion of the difference in cognitive performance between persons with and without HIV

OBJECTIVE

To investigate whether psychosocial factors account for a proportion of the difference in cognitive performance between persons with and without HIV.

DESIGN

Cross-sectional study of 273 participants (178 persons with HIV) from a low income area of Cape Town, South Africa.

METHODS

Participants completed comprehensive cognitive testing (7 domains) and 12 psychosocial measures (5 current: income, occupation, assets, accommodation, depressive symptoms, 7 from childhood: assets, quality of education, exposure to childhood trauma and violence, primary caregiver occupation and highest level of education), as well as demographic measures standard in cognition studies (age, sex, years of education). We investigated the HIV association with global cognitive performance after adjustment for standard demographic variables, exploratory psychosocial variables, and balancing characteristics of those with and without HIV using propensity score modelling.

RESULTS

Persons with HIV had significantly lower scores than persons without HIV in 8/12 psychosocial variables. Of these, 7/12 significantly predicted global T-score. In unadjusted regression, HIV status was associated with a reduction in global T-score of 3.72 units. Adjustment for standard variables, reduced the effect of HIV on global T score by 26.9% to 2.72, additional adjustment for psychosocial variables reduced by 40.3% to 2.22, and adjustment for propensity scores by 42.7% to 2.13.

CONCLUSIONS

Persons with HIV in this setting have lower psychosocial indices, both current and in childhood, which are associated with lower cognitive test performance as an adult. This is incompletely mitigated by adjustments for standard demographic variables which risks overestimation of cognitive impairment on a population level.

HIV-associated neurocognitive disorders (HAND): Optimal diagnosis, antiviral therapy, pharmacological treatment, management, and future scopes

In the context of HIV infection, HIV-associated neurocognitive disorders (HAND) have become a serious concern. An extensive summary of the diagnosis, care, and mental health consequences related to HAND is given in this article. The diagnosis of HAND entails a multimodal approach that includes neuroimaging, cognition tests, and clinical examinations. Numerous screening instruments and standardized evaluations have been created to support the early identification and tracking of HAND. Appropriate actions and individualized treatment plans are made possible by prompt diagnosis. A multidisciplinary approach is used in the treatment of HAND, aiming to address various elements of cognitive impairment. The main stream of treatment is still antiretroviral medication (ART), which successfully lowers viral loads and stops further neurocognitive deterioration. Adjunctive treatments are essential for treating cognitive symptoms and improving overall quality of life. These therapies include cognitive rehabilitation, pharmaceutical interventions, and psychological support. Our knowledge of the pathophysiology of HAND has improved with the identification of the inflammatory milieu and persistent viral persistence in the central nervous system (CNS), which has also aided in the creation of biomarkers for CNS illness. Although biomarkers show inflammation, neuronal damage, and monocyte activity, their clinical use is still restricted. Although new techniques to treating HAND have been developed as a result of a better knowledge of pathogenic processes, the best course of action is still unknown.

Evolving strategies in the diagnosis and treatment of HIV-associated neurocognitive disorders

Despite significant progress in managing HIV infection, HIV - associated neurocognitive disorder (HAND) continues to be a concern even among HIV individuals with well - controlled infection. Current diagnostic strategies, primarily reliant on neuropsychological tests, neuroimaging, and biomarkers from blood and cerebrospinal fluid, alongside combination antiretroviral therapy, form the foundation of HAND management. However, these strategies often fail to identify early or mild HAND, particularly asymptomatic neurocognitive impairment, resulting in delayed diagnosis and intervention. Furthermore, the inability to perform in-depth molecular analyses and conduct longitudinal tracking limits therapeutic advancements. Emerging technologies - advanced neuroimaging, multi-omics, artificial intelligence, alongside simian immunodeficiency virus non-human primate models - are revolutionizing the field. These innovations offer unprecedented opportunities for deeper understanding of the disease mechanism, early detection, comprehensive monitoring, and personalized treatment strategies. Integrating these cutting-edge tools promises to reshape the landscape of HAND management, enhancing the quality of life for those living with HIV.

In Support of Multidimensional Frailty: A Structural Equation Model from the Canadian Positive Brain Health Now Cohort

The objective of this study was to estimate the structure and relationships between four h ypothesized frailty dimensions (physical, emotional, cognitive, and social) and the extent to which personal and HIV-related factors and comorbidity associate with these frailty dimensions. This is a secondary analysis of an existing dataset arising from Positive Brain Health Now study (n = 856) in people aging with HIV (mean age: 52.3 ± 8.1 years). Structural equation modeling (SEM) models were applied to two cross-sections of the data: one at study entry and one at second visit, 9-month apart. Multidimensional frailty was modeled based on the combined Wilson-Cleary and International Classification of Functioning, Disability and Health framework. Four dimensions were operationalized with patient-reported and self-report measures from standardized questionnaires. The SEM model from the first visit was replicated using data from the second visit, testing measurement invariance. The proposed model showed acceptable fit at both visits (including no violation of measurement invariance). The final model for the first visit showed that sex, body mass index, HIV diagnosis pre-1997, current or nadir CD4 counts, and comorbidity did not associate with any frailty dimension; however, age (β range: 0.12-0.25), symptoms (β range: -0.35 to -0.58), and measured cognition (β range: 0.10-0.24) directly associated with all frailty dimensions. The model remained stable across the two visits. This study contributes evidence for operationalizing multidimensional frailty. Evidence-based interventions are available for many of the measures considered here, offering opportunities to improve the lives of people with frailty in the context of HIV.

Impact of switching from efavirenz/emtricitabine/tenofovir disoproxil fumarate to bictegravir/emtricitabine/tenofovir alafenamide on psychiatric symptoms and neurocognition

OBJECTIVES

The aim was to investigate whether switching from efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/F/TDF) to bictegravir/emtricitabine/tenofovir alafenamide (BIC/F/TAF) may improve neuropsychiatric symptoms and neurocognition.

DESIGN

Pilot, single-arm, prospective study of persons with HIV (PWH) on the efficacy and safety of switching from EFV/F/TDF to BIC/F/TAF.

METHODS

Participants underwent neuropsychological assessment (NPA) at switch (T0) and after 48 weeks (T1). NPA was carried out through a standardized battery of 12 tests. Neurocognitive impairment (NCI) was defined by a score of at least 1 standard deviation (SD) below the normal mean on at least two tests or ≥2 SD below on one test. Individual z scores were determined, NPZ-12 was calculated as the average of 12 test z scores and change of NPZ-12 was the outcome. HIV-associated neurocognitive disorder (HAND) was classified by Frascati's criteria. Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI-II), and Pittsburgh Sleep Quality Index (PSQI) were administered. Paired-Wilcoxon and McNemar tests were used for comparisons, and logistic regression for associations with NCI changes.

RESULTS

Out of 126 participants, BAI, BDI-II, and PSQI questionnaires revealed an improvement at T1. NPA revealed NCI in 40.5% of persons at T0 and 42.1% at T1 ( P  = 0.746). Specifically, at T0, among participants with NCI, 35% improved; among those without, 26% worsened at T1; NPZ-12 score worsened at T1. 5.6% of ANI was observed at T0 and 7.9% at T1. No factor associated with these changes was found.

CONCLUSION

Our results suggest switching from EFV/F/TDF to B/F/TAF significantly improves psychiatric symptoms and sleep quality. Neurocognitive performance remained stable, although a decline in NPZ-12 and in specific domains was observed.

Assessing cognitive impairment in HIV-infected: a comparative study of international HIV Dementia Scale, HIV Dementia Scale Italian version and Montreal cognitive assessment in clinical practice

The combination of antiretroviral therapy (cART) and preventive measures has significantly enhanced the management of Human Immunodeficiency Virus (HIV) infection. However, HIV-associated neurocognitive disorders (HAND) remain a challenge. This study aims to compare cognitive impairment (CI) assessments in people living with HIV/AIDS (PLWHA) using the International HIV Dementia Scale (IHDS), HIV Dementia Scale-Italian Version (HDS-IT) and MoCA (Montreal Cognitive Assessment), while also identifying significant associations. The cross-sectional study encompassed 294 outpatient PLWHA (median age: 57) on cART. Participants underwent cognitive, functional, and depression assessments, laboratory testing and CNS Penetration-Effectiveness (CPE) index assessment. IHDS, HDS-IT and MoCA identified CI in different proportions of PLWHA. Factors such as age, education level, infection duration, and substance use were associated with CI. The IHDS score (OR 0.79) and Level CD4 + T-lymphocytes nadir (OR 0.99) demonstrated independent and negative associations with the CPE-index. IHDS and MoCA tests appear to be useful for detecting CI in outpatient settings, enabling healthcare providers to conduct initial evaluations of PLWHA. IHDS assessment may be used for detecting CI related to high CPE regimens, while the MoCA provides a comprehensive assessment, also in domains not studied by IHDS. However, further research is needed to confirm these findings and refine their clinical applicability.

Chronic, Low-Dose Methamphetamine Reveals Sexual Dimorphism of Memory Performance, Histopathology, and Gene Expression Affected by HIV-1 Tat Protein in a Transgenic Model of NeuroHIV

Methamphetamine (METH) use is frequent among people with HIV (PWH) and appears to increase the risk of neuronal injury and neurocognitive impairment (NCI). This study explored in vivo the effects of a 12 week (long-term), low-dose METH regimen in a transgenic animal model of neuroHIV with inducible expression of HIV-1 transactivator of transcription (Tat). Seven months after transient Tat induction and five months after METH exposure ended, we detected behavioral changes in the Barnes maze (BM) spatial memory task in the Tat and METH groups but not the combined Tat + METH group. The novel object recognition (NOR) task revealed that Tat extinguished discrimination in female animals with and without METH, although METH alone slightly improved NOR. In contrast, in males, Tat, METH, and Tat + METH all compromised NOR. Neuropathological examination detected sex-dependent and brain region-specific changes of pre-synaptic terminals, neurites, and activation of astrocytes and microglia. RNA-sequencing and quantitative reverse transcription polymerase chain reaction indicated that METH and Tat significantly altered gene expression, including factors linked to Alzheimer's disease-like NCI. In summary, chronic low-dose METH exerts long-term effects on behavioral function, neuropathology, and mRNA expression, and modulates the effects of Tat, suggesting sex-dependent and -independent mechanisms may converge in HIV brain injury and NCI.

Association between plasma short-chain fatty acids and inflammation in human immunodeficiency virus-associated neurocognitive disorder: a pilot study

BACKGROUND AND AIMS

Short-chain fatty acids (SCFAs), key metabolites produced by gut microbiota, have neuroprotective effects in neurodegenerative diseases by modulating immune responses. However, their role in human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) remains largely unexplored.

METHODS

We recruited HAND patients, HIV Control, and healthy controls (HC). Plasma SCFAs and SCFA-producing gut microbiota were quantified via gas chromatography-mass spectrometry and fecal metagenomic analysis. Inflammatory cytokine levels were measured using liquid chromatography. Receiver operating characteristic (ROC) curves were generated to evaluate the predictive accuracy of SCFAs for HAND.

RESULTS

Plasma SCFAs were significantly reduced in HAND patients, correlating with a decrease in SCFA-producing gut bacteria, such as Prevotella and its related species. Reduced SCFAs were positively correlated with pro-inflammatory cytokines and cognitive impairment, while being negatively correlated with anti-inflammatory cytokines. ROC curve analysis demonstrated that several SCFAs exhibited strong predictive accuracy for HAND status.

CONCLUSIONS

SCFAs may influence cognitive function by modulating inflammatory responses, and identifies plasma SCFAs as potential biomarkers and therapeutic targets for HAND. Further investigation is needed to delineate the mechanisms that SCFAs influence HAND pathology.

The Role of HMGB1 in Infection-Related Cognitive Deficits

Infectious diseases caused by fungi, viruses, or bacteria can have a profound impact on human cognition. This can be due to either direct spread to the central nervous system (CNS) or indirect neuroinflammation. Ultimately causing neuronal damage and even neurodegeneration. Deteriorations in cognition, such as poor encoding and attention deficits, have been reported secondary to infectious diseases. Preclinical studies have identified the underlying mechanisms of these infection-related cognitive effects, such as through blood-brain barrier (BBB) disruption and M1 microglial polarization. These mechanisms are spearheaded by inflammatory markers that are released/initiated by the pathogens over the course of the infection. Among them, the high mobility group box 1 (HMGB1) protein is a common biomarker implicated across several infection-related cognitive deficits. Understanding these effects and mechanisms is crucial for the development of strategies to prevent and treat infection-related cognitive impairment. This review will thus consolidate and elucidate the current knowledge on the potential role of HMGB1 as a therapeutic target for infection-related cognitive impairments. This review will not only advance scientific understanding but also have significant clinical and public health implications, especially considering recent global health challenges. Based on the selected articles, extracellular HMGB1, as opposed to intracellular HMGB1, acts as damage-associated molecular patterns (DAMPs) or alarmins when released in the peripheries secondary to inflammasome activation. Due to their low molecular weight, they then enter the CNS through routes such as retrograde transport along the afferent nerves, or simple diffusion across the impaired BBB. This results in further disruption of the brain microenvironment due to the dysregulation of other regulatory pathways. The outcome is structural neuronal changes and cognitive impairment. Given its key role in neuroinflammation, HMGB1 holds promise as both a biomarker for diagnostic detection and a potential therapeutic target candidate for preventing infection-related cognitive impairment.

Altered angular gyrus activation during the digit symbol substitution test in people living with HIV: beyond information processing speed deficits

Speed-of-information processing (SIP) is often impaired in people living with HIV (PLWH), typically assessed through tests such as the digit symbol (DS) and symbol search, which also rely on motor and executive functions. This study aims to disentangle SIP deficits from other cognitive impairments in PLWH using an MRI-adapted digit symbol substitution test (mDSST). Fifty-seven PLWH (34.7 ± 11.2 years) and 50 age-matched people living without HIV (PLWoH, 31.8 ± 9.9 years) completed standardized neuropsychological tests and the mDSST. Behavioral performances and brain activations were compared, with correlations drawn between group-differentiating brain activations and clinical ratings of cognitive domains. Results showed that PLWH performed worse in DS and symbol search, made fewer responses, and was slower in mDSST, with performances correlating to SIP and motor ratings. Notably, PLWH showed greater deficits in attention compared to PLWoH, rather than in SIP or motor. PLWH also exhibited greater primary motor cortex activation and reduced right angular gyrus activation. These findings suggest that slower performances on SIP-related tests in PLWH may be partially linked to abnormal visuospatial attention, as reflected by reduced angular gyrus activation, with higher motor cortex activation potentially serving as a compensatory mechanism. Future studies should explore whether prefrontal regions implicated in SIP are impaired in more severely affected PLWH.

Neuroimaging advances in neurocognitive disorders among HIV-infected individuals

Although combination antiretroviral therapy (cART) has been widely applied and effectively extends the lifespan of patients infected with human immunodeficiency virus (HIV), these patients remain at a substantially increased risk of developing neurocognitive impairment, commonly referred to as HIV-associated neurocognitive disorders (HAND). Magnetic resonance imaging (MRI) has emerged as an indispensable tool for characterizing the brain function and structure. In this review, we focus on the applications of various MRI-based neuroimaging techniques in individuals infected with HIV. Functional MRI, structural MRI, diffusion MRI, and quantitative MRI have all contributed to advancing our comprehension of the neurological alterations caused by HIV. It is hoped that more reliable evidence can be achieved to fully determine the driving factors of cognitive impairment in HIV through the combination of multi-modal MRI and the utilization of more advanced neuroimaging analysis methods.

Body Fluid Biomarkers of Neurological Injury in HIV-1-Associated Neurocognitive Disorder

Since combined antiretroviral therapy for human immunodeficiency virus-associated neurocognitive dysfunction (HAND) only slows the disease's progression, early identification and timely intervention are crucial for effective therapy. In this article, we review the latest evidence in body fluid biomarkers of HAND, providing an overview of research conducted on cerebrospinal fluid and blood samples to draw conclusions on promising biomarkers. Although the significance of biomarkers such as amyloid metabolites, tau proteins, neurofilament light chain, myelin oligodendrocyte glycoprotein, and brain-derived neurotrophic factor in the early detection of HAND may not be immediately clear, they could potentially play a crucial role in evaluating prognosis and tracking the effectiveness of treatment.

Development of research on HIV-associated neurocognitive disorder and emerging trends: a visualization analysis via CiteSpace

Background

In the combination antiretroviral therapy era, HIV-associated neurocognitive disorder (HAND) is still widespread among HIV-infected individuals. However, there is no effective treatment for HAND, and the exact pathogenic mechanism of HAND remains unknown. This paper aims to provide a reference for further exploration in the field of HAND research.

Methods

We used CiteSpace software to collect 3057 articles related to HAND in the Web of Science Core Collection for comprehensive analysis. Betweenness centrality, count, and burst values were used as indicators in the visualization analysis, aiming to predict future new directions and cutting-edge trends.

Results

The last decade has been the peak period of HAND research, with the most prominent contributions by authors, countries, and institutions being Grant, Igor (135), the USA (2211), and the University of California System (758), respectively. The most frequently cited article is "HIV-associated neurocognitive disorders persist in the area of potent antiretroviral therapy: CHARTER Study." The hotspots in this field are "neurocognitive impairment," "central nervous system," "cerebrospinal fluid," "HIV-1 tat," "SIV," "inflammation," "infection," and "pathogenesis." The current research direction of HAND is focused on exploring the pathogenic mechanism underlying HIV-associated neurocognitive impairment and potential therapeutic targets.

Conclusion

This study provides a bibliometric visualization of HAND-related literature to gain insight into the development and frontiers of this research field. The study also provides scholars with detailed references and identifies future research directions to better promote the development of this field of research.

MicroRNA in neuroexosome as a potential biomarker for HIV-associated neurocognitive disorders

HIV-associated neurocognitive disorder (HAND) is a complication of chronic inflammation caused by HIV infection that impairs cognitive and motor functions. HAND can occur at any age, regardless of the duration of infection, even in people living with HIV (PLWH) whose blood viral load is controlled by antiretroviral therapy. The diagnosis of HAND requires a battery of neuropsychological tests, which is time-consuming and burdensome, limiting its effectiveness for screening PLWH. Here, we aimed to identify biomarkers for quantitatively diagnosing and screening for HAND using minimally invasive blood tests. Neuronal-derived exosomes (neuroexosomes) were isolated from the peripheral blood of PLWH, and the transcriptomes of their microRNAs (miRNAs) were analyzed. We identified five upregulated miRNAs (hsa-miR-16-5p, hsa-miR-26a-3p, hsa-92a-3p, hsa-miR-103a-3p, and hsa-miR-185-5p), and two downregulated miRNA (hsa-miR-3613-3p and hsa-miR-4668-5p) in PLWH diagnosed with HAND (HAND PLWH). Functional analysis of five miRNAs whose expression levels increased in HAND PLWH using the database showed that these miRNAs are involved in motor proteins and endocytosis, which are associated with nerve function. The expression levels of hsa-miR-16-5p, hsa-miR-103a-3p, and hsa-miR-185-5p were significantly higher than those in the non-HIV controls and non-HAND PLWH, suggesting that these miRNAs are potential biomarkers for HAND. Since there were no changes in known dementia miRNA biomarkers in HAND PLWH, the miRNAs identified in this study will allow for early differentiation of HAND.

Association between a lower T-CD4+ /CD8+ lymphocyte ratio and cognitive impairment in older persons with HIV

PURPOSE

To ascertain the association between the LT-CD4 + /CD8 + ratio and cognitive impairment in older people living with HIV.

METHODS

A cross-sectional study was conducted, including 207 adults aged > 50 years with HIV, receiving care at a tertiary-care hospital in Mexico City. Participants underwent a standardized geriatric and neuropsychological assessment to establish the presence of HIV-associated neurocognitive disorder according to the validated Antinori criteria. Multivariate logistic regression models were performed to determine the association between T-CD4 + /CD8 + lymphocyte ratio tercile values (0.57-0.91, and < 0.56; with > 0.91 being the reference category) and cognitive impairment.

RESULTS

Participants' median age was 56 (IQR 53-62) years and 173 (83.6%) were men. The prevalence of any kind of cognitive impairment according to the Antinori criteria was 66.2% (n = 137), the highest proportion being asymptomatic neurocognitive impairment (n = 114, 83.2%). Adjusted logistic regression analyses showed that the lowest LT-CD4 + /CD8 + ratio tercile values (< 0.56) were independently associated with the presence of cognitive impairment (OR 3.16; 95% CI 1.22-8.16, p = 0.017).

CONCLUSION

Lower LT-CD4 + /CD8 + ratios are independently associated with cognitively impaired older persons with HIV, which represents another factor that could be addressed to identify individuals at risk and focus on cognitive screening as well as correction of other modifiable risk factors.

Risk factors for cognitive decline in persons with HIV

PURPOSE OF REVIEW

Cognitive disorders persist in persons with HIV, despite virologically suppressive antiretroviral therapy. We summarize the current evidence on risk factors for cognitive decline in persons with HIV in the modern antiretroviral therapy-era.

RECENT FINDINGS

Recent consensus recommendations have proposed a new approach for defining cognitive impairment in persons with HIV, which distinguishes true cognitive impairment from low cognitive performance alone and considers both HIV and non-HIV-associated causes of brain injury. Adverse mental health, risks associated with substance misuse, and an increasing burden of age-related comorbidities have been highlighted as important contributors toward cognitive decline in this population. Aging may potentiate these risk factors through polypharmacy and drug-drug interactions.

SUMMARY

Cognitive decline in persons with HIV is likely multifactorial, with contributions from both HIV and non-HIV-associated mechanisms, particularly age-related comorbidities. With an aging community of persons with HIV, screening for risk factors associated with cognitive decline may be crucial to implement appropriate risk reduction strategies.

Transformation of brain myeloid cell populations by SIV in rhesus macaques revealed by multiomics

The primary immune constituents in the brain, microglia and macrophages, are the target for HIV in people and simian immunodeficiency virus (SIV) in nonhuman primates. This infection can lead to neurological dysfunction, known as HIV-associated neurocognitive disorder (HAND). Given the gaps in our knowledge on how these cells respond in vivo to CNS infection, we perform single-cell multiomic sequencing, including gene expression and ATAC-seq, on myeloid cells from the brains of rhesus macaques with SIV-induced encephalitis (SIVE) as well as uninfected controls. We find that SIVE significantly changes the myeloid cell populations. In SIVE, microglia-like cells express high levels of chemoattractants capable of recruiting highly activated CAM-like cells to the site of infection/inflammation. A unique population of microglia-like cells is found in which the chromatin accessibility of genes diverges from their RNA expression. Additionally, we observe a dramatic shift of upstream gene regulators and their targets in brain myeloid cells during SIVE. This study further uncovers the transcriptome, gene regulatory events, and potential roles of different brain myeloid phenotypes in SIVE. This might deepen the understanding of SIVE/HIVE and enlighten the therapeutic development.

Social Determinants of Health and Cross-Sectional Cognitive Intra-Individual Variability in Adults from the Deep South Living with HIV

Cognitive intra-individual variability (IIV) is a sensitive marker of neuropathology and is increased in people with HIV (PWH). In a sample of PWH from the United States Deep South, we examined the relationship of cognitive IIV with cognitive impairment and social determinants of health (SDoH). This secondary analysis included 131 PWH from a larger cognitive training protocol. Our primary outcome measure was the coefficient of variation (CoV). We also included the individual standard deviation (iSD), with both calculated from demographically adjusted T-scores and unadjusted sample-based scores. Mixed-effects models investigated the relationship between IIV and cognitive impairment severity (i.e., Global Rating Score), SDoH, and clinical variables. Bivariate correlations were used to further explore these relationships. Greater cognitive IIV was associated with greater cognitive impairment in PWH, when accounting for demographic factors. When IIV is calculated from the sample, then IIV is no longer associated with cognitive impairment, but is associated with race (>IIV in Black and African American participants). Demographically adjusted IIV is associated with global cognition, Wide Range Achievement Test-Fourth Edition reading score, and viral load (iSD only). No correlations were significant when using the unadjusted sample-based IIV metrics. In PWH from the Deep South, greater cognitive variability is seen in those with greater cognitive impairment, in Black participants, and in those with lower reading scores. Further research on the psychometric properties of IIV in HIV and other populations is needed, as results varied depending on the normative adjustments.

Neurological impact of HIV/AIDS and substance use alters brain function and structure

Human immunodeficiency virus (HIV) infection is the cause of acquired immunodeficiency syndrome (AIDS). Combination antiretroviral therapy (cART) has successfully controlled AIDS, but HIV-associated neurocognitive disorders (HANDs) remain prevalent among people with HIV. HIV infection is often associated with substance use, which promotes HIV transmission and viral replication and exacerbates HANDs even in the era of cART. Thus, the comorbid effects of substance use exacerbate the neuropathogenesis of HANDs. Unraveling the mechanism(s) of this comorbid exacerbation at the molecular, cell-type, and brain region levels may provide a better understanding of HAND persistence. This review aims to highlight the comorbid effects of HIV and substance use in specific brain regions and cell types involved in the persistence of HANDs. This review includes an overview of post-translational modifications, alterations in microglia-specific biomarkers, and possible mechanistic pathways that may link epigenomic modifications to functional protein alterations in microglia. The impairment of the microglial proteins that are involved in neural circuit function appears to contribute to the breakdown of cellular communication and neurodegeneration in HANDs. The epigenetic modification of N-terminal acetylation is currently understudied, which is discussed in brief to demonstrate the important role of this epigenetic modification in infected microglia within specific brain regions. The discussion also explores whether combined antiretroviral therapy is effective in preventing HIV infection or substance-use-mediated post-translational modifications and protein alterations in the persistence of neuropathogenesis in HANDs.

PKR Inhibitor C16 Regulates HIV-gp120 Induced Neuronal Injury and Cognitive Impairment in Vivo and in Vitro Models

To study the neuronal protective effect and its potential mechanism of C16 against gp120-induced cognitive impairment in vitro and in vivo. The NORT method was used to evaluate the short-term memory abilities of rats, the morphological changes in hippocampus were observed by Nissl staining. Cell viability and damage degree were detected by MTT and LDH. The cell living/apoptosis status of PC12 cells was determined by AO/EB double staining and the relative mRNA expressions of PKR, IRE1α, JNK, GRP78, and CHOP were detected by RT-qPCR. In comparison with the gp120 + Memantine and gp120 + C16 groups, the rats in the gp120 group showed a significantly decreased discrimination index (P < 0.001), with disordered CA1 region cells and reduced neuron numbers. AO/EB double staining revealed morphological changes in the gp120 and NMDA groups, while cells in the gp120 + C16 and NMDA + C16 groups resembled the control group. And C16 can significantly down-regulate the mRNA expression levels of PKR, IRE1α, JNK, GRP78, and CHOP. (P < 0.05). C16 can reduce the cognitive impairment stimulated by gp120 or NMDA, the protective mechanism may be correlated with inhibiting the upregulation of PKR/IRE1α/JNK pathway and suppressing apoptosis induced by downstream proteins GRP78 and CHOP.

Alterations in local activity and whole-brain functional connectivity in human immunodeficiency virus-associated neurocognitive disorders: a resting-state functional magnetic resonance imaging study

Background

Approximately half of human immunodeficiency virus (HIV) patients experience HIV-associated neurocognitive disorders (HAND); however, the neurophysiological mechanisms underlying HAND remain unclear. This study aimed to evaluate changes in functional brain activity patterns during the early stages of HIV infection by comparing local and global indicators using resting-state functional magnetic resonance imaging (rs-fMRI).

Methods

A total of 165 people living with HIV (PLWH) but without neurocognitive disorders (PWND), 173 patients with asymptomatic neurocognitive impairment (ANI), and 100 matched healthy controls (HCs) were included in the study. A cross-sectional study of the participants was conducted. The metrics of functional segregation and integration were computed, using graph theory to explore differences across methodologies. Brain functional changes in the PWND and ANI groups were assessed, and correlations between the rs-fMRI metrics, clinical data, and cognitive function were examined.

Results

As cognitive function declined, changes reflected by regional homogeneity (ReHo) were primarily observed in the default mode network (DMN). In the DMN and visual network (VIS), amplitude of low-frequency fluctuation (ALFF) decreases were mainly observed in the parieto-occipital lobes, while increases were mainly observed in the limbic network (LIM). Reductions in fractional ALFF (fALFF) were mainly observed in the somatomotor network (SMN) and LIM, while increases were observed in the DMN and LIM. Unlike local indicators, global functional connectivity (FC) significantly decreased in both the PWND and ANI groups compared to the HC group. The ANI group showed partial increases in FC compared to the PWND group, with major changes observed in the DMN, VIS, and LIM. Notably, FC between the right insula and right supramarginal gyrus decreased significantly following HIV infection, while FC between the right caudate nucleus and the left middle frontal gyrus declined further in the ANI group. Graph theory further confirmed the significance of the DMN, and revealed changes in the eigenvector centrality mapping (ECM) values of the frontoparietal network (FPN) and dorsal attention network (DAN).

Conclusions

HIV patients exhibit complex changes in both local and global brain activity, regardless of cognitive impairment. Widespread abnormalities primarily involve the DMN, VIS, and LIM. Changes in FC along the fronto-striatal pathway may play a crucial role in the decline of cognitive function in individuals with HAND. Our findings provide new insights that may assist in the early detection of brain damage in the early stages of HIV infection. The use of multiple methodologies may offer a more comprehensive and effective approach, enabling the early detection of brain damage in HIV patients.

Fostering healthy cognitive ageing in people living with HIV

Prevalence and incidence of HIV among people aged 50 years and older continue to rise worldwide, generating increasing awareness among care providers, scientists, and the HIV community about the importance of brain health in older adults with HIV. Many age-related factors that adversely affect brain health can occur earlier and more often among people with HIV, including epigenetic ageing, chronic medical conditions (eg, cardiovascular disease), and age-related syndromes (eg, frailty). Extensive dialogue between HIV community leaders, health-care providers, and scientists has led to the development of a multidimensional response strategy to protect and enhance brain health in people ageing with HIV that spans across public health, clinical spaces, and research spaces. This response strategy was informed by integrated ageing care frameworks and is centred on prevention, early detection, and management of brain health issues associated with HIV (eg, neurocognitive disorders), with specific considerations for low-resource or middle-resource countries. A collaborative, international, and data-informed update of the diagnostic criteria for HIV-associated neurocognitive disorders is a cornerstone of the proposed response strategy. The proposed response strategy includes a dynamic, international, online knowledge hub that will provide a crucial community resource for emerging evidence on the brain health of people ageing with HIV.

Normative data for executive function tests in an Ecuadorian Waranka minority population

Objective: To generate normative data (ND) for executive functions tests in the Waranka minority population of Ecuador. Method: Four-hundred participants aged 6-17 completed the Symbol-Digit Modalities Test (SDMT), Trail-Making Test (TMT), Modified-Wisconsin Card Sorting Test (M-WCST), and Test of Colors-Words (STROOP). Scores were normed using multiple linear regressions, including age, age2, natural logarithm of mean parent education (MPE), sex, bilingualism, and two-way interactions as predictors. Results: Age by MPE and Age2 by MPE interactions arose for SDMT, so that children with illiterate parents scored lower than those with literate parents. Girls scored higher in SDMT. All TMT and M-WCST scores were influenced by age2. Age by MPE interaction was found for TMT-A, so that children with higher MPE went faster; and age by bilingualism interaction for TMT-B, so that more bilingual children needed less time. Stroop-Word and Color were influenced by age2 by MPE interaction, so that children, while older, scored higher, especially those with higher MPE. Also, age2 by sex interaction arose, so that girls increased scores curvilinearly while boys linearly. Word-Color was influenced by age, while Stroop-interference by age2. Age by MPE interaction was found for MCST-Categories and Perseveration, so that perseverations decreased to then increased, especially in those with illiterate parents. M-WCST-Category scores increased to then decrease later on age in children with illiterate parents. Z-scores calculated through indigenous ND were significantly lower than generated through non-indigenous norms. Conclusions: ND for minority populations are critical since Waranka sample performed worse when using non-indigenous norms for z-score calculation.

Patient-specific brain fluorodeoxyglucose positron emission tomography can detect the first effects of combination antiretroviral therapy in patient with HIV infection

Patient-specific brain fluorodeoxyglucose-positron emission tomography (FDG PET) can detect areas with abnormal FDG uptake in patients with human immunodeficiency virus (HIV) before and after combination antiretroviral therapy (cART). There were few reports about the same patients before and shortly after cART in FDG PET. It is well known that HIV-RNA levels decrease and cognitive impairments in patients with HIV tend to improve on neurocognitive performance tests 6 months after starting cART. We conducted a quantitative imaging analysis (FDG PET and voxel-based morphometry (VBM)) of eight patients at pre- and 6 months post- cART with neurocognitive performance tests. In terms of participant-specific changes between pre- and post-cART imaging, some area showed that the size of area with abnormal FDG uptake shrunk and became a nearly physiological level at 6 months post-cART. No apparent changes in VBM were observed in this short period. FDG PET might detect the first effect of cART.

p62 Binding to Protein Kinase C Regulates HIV-1 gp120 V3 Loop Induced Microglial Inflammation

The main pathogenic mechanism of HIV-associated neurocognitive disorders (HAND) is neuronal apoptosis induced by inflammatory mediators, in which microglial inflammation plays a crucial role. However, the exact pathogenic mechanism remains unclear. Previous studies have shown that the HIV-1 gp120 V3 loop can trigger inflammation in CHME-5 microglia. p62 is a post-translational modified multidomain protein that is involved in the regulation of autophagy and is closely related to neuroinflammation. In this study, we found that p62 knockout down-regulated the expression of MCP-1, IL-6 and COX-2, and improved the inflammation of HIV-1 gp120 V3 loop induced microglia, while overexpression of p62 up-regulated the expression of MCP-1, IL-6 and COX-2, and promoted the inflammation of microglia. In addition, protein kinase C (PKC) knockout down-regulated the expression of MCP-1, IL-6 and COX-2 and inhibited the activation of IKK/ NF-κ B pathway, while tumor necrosis factor receptor-associated factor 6 (TRAF6) knockout had no significant effect on the expression of MCP-1, IL-6 and COX-2. Co-immunoprecipitation showed that p62 was bound and interacted with PKC. Inhibition of IKK/ NF-κ B pathway can down-regulate the expression of MCP-1, IL-6 and COX-2, and improve the inflammatory response of microglia. Our research further found that inhibition of IKK/ NF-κ B can decrease the expression of Caspase-3 and reduce the apoptosis of neurons in the co-culture of CHME-5 microglia and primary mouse neurons. The results of this study suggest that HIV-1 gp120 V3 loop induced CHME-5 microglial inflammation may be activated by the direct binding of p62 and PKC through the IKK/ NF-κ B signaling pathway, and these findings provide an important reference for the prevention and treatment of HAND.

Advances in assessment and cognitive neurorehabilitation of HIV-related neurocognitive impairment

Neurocognitive impairment (NCI) is present in around 40% of people with HIV and substantially affects everyday life, adherence to combined antiretroviral therapy (cART) and overall life expectancy. Suboptimal therapy regimen, opportunistic infections, substance abuse and highly prevalent psychiatric co-morbidities contribute to NCI in people with HIV. In this review, we highlight the need for efficacious treatment of HIV-related NCI through pharmacological approaches and cognitive neurorehabilitation, discussing recent randomized controlled trials in this domain. We also discuss the benefits of a thorough and interdisciplinary diagnostic work-up between specialists in neurology, psychiatry, neuropsychology and infectious diseases, helping to disentangle the various factors contributing to cognitive complaints and deficits in people with HIV. While the advent of cART has contributed to slowing the progression of cognitive deficits in people with HIV and reducing the prevalence of HIV-associated dementia, NCI persists at a significant rate. Adjuvant stimulating or neuroprotective pharmacological agents have shown some potential benefits. Despite promising outcomes, studies on cognitive neurorehabilitation of HIV-related NCI remain sparse and limited in terms of methodological aspects. The access to cognitive neurorehabilitation is also restricted, in particular at the global scale. Novel technology bears a significant potential for restoring cognitive function in people with HIV, affording high degrees of standardization and personalization, along with opportunities for telerehabilitation. Entertaining serious video game environments with immersive graphics can further promote patient motivation, training adherence and impact on everyday life, as indicated by a growing body of evidence, including in seropositive children and older individuals in Africa. Upon validation of technology-assisted cognitive neurorehabilitation for HIV-related NCI in large-scale randomized controlled trials with state-of-the-art methodology, these approaches will promote socio-professional reintegration and quality of life of people with HIV.

Examining objective and subjective sleep measures and neurocognition in older adults with HIV: A cross-sectional study in the deep South

As people live longer with HIV, reports of poor sleep and neurocognitive impairments are expected to increase. Poor sleep and neurocognitive impairments commonly occur in people living with HIV (PLWH) and some medications (e.g., anticholinergics) contribute to these problems. The association between sleep and neurocognition among PLWH taking such medications remains unclear. This study examined trend level associations between neurocognitive domains and subjective and objective sleep outcomes. Among 29 PLWH (Mage = 61 years old), the use of anticholinergics and/or antidepressants were examined as a moderator between neurocognition and sleep outcomes. For PLWH taking anticholinergics and/or antidepressants, the associations between insomnia and neurocognitive measures were counter-intuitive, and so were the associations between sleep time and neurocognitive measures. For these adults, objective longer sleep time was associated with poorer verbal learning (immediate, p = .005; delayed recall, p = .002) and visuospatial memory (delayed recall, p = .010). Greater sleep efficiency was associated with better visuospatial memory (immediate, p = .007; delayed recall p = .022). Despite sleep benefits, the use of anticholinergics and/or antidepressants may compromise neurocognitive function in older PLWH. Clinical implications include routine sleep and neurocognitive assessments along with medication monitoring to detect adverse neurocognitive effects of commonly prescribed medications.

Nicotine is an Immunosuppressant: Implications for Women's Health and Disease

A plethora of evidence supports that nicotine, the primary alkaloid in tobacco products that is generally accepted for maintaining use, is immunoregulatory and may function as an immunosuppressant. Women have unique experiences with use of nicotine-containing products and also undergo significant reproductive transitions throughout their lifespan which may be impacted by nicotine use. Within the extant literature, there is conflicting evidence that nicotine may confer beneficial health effects in specific disease states (e.g., in ulcerative colitis). Use prevalence of nicotine-containing products is exceptionally high in individuals presenting with some comorbid disease states that impact immune system health and can be a risk factor for the development of diseases which disproportionately impact women; however, the mechanisms underlying these relationships are largely unclear. Further, little is known regarding the impacts of nicotine's immunosuppressive effects on women's health during the menopausal transition, which is arguably an inflammatory event characterized by a pro-inflammatory peri-menopause period. Given that post-menopausal women are at a higher risk than men for the development of neurodegenerative diseases such as Alzheimer's disease and are also more vulnerable to negative health effects associated with diseases such as HIV-1 infection, it is important to understand how use of nicotine-containing products may impact the immune milieu in women. In this review, we define instances in which nicotine use confers immunosuppressive, anti-inflammatory, or pro-inflammatory effects in the context of comorbid disease states, and focus on how nicotine impacts neuroimmune signaling to maintain use. We posit that regardless of potential health benefits, nicotine use cessation should be a priority in the clinical care of women. The synthesis of this review demonstrates the importance of systematically defining the relationships between volitional nicotine use, immune system function, and comorbid disease states in women to better understand how nicotine impacts women's health and disease.

Application status and prospects of multimodal EEG-fMRI in HIV-associated neurocognitive disorders

HIV-associated neurocognitive disorders (HAND) are one of the common complications in people living with HIV (PLWH), which can affect their attention, working memory, and other related cognitive functions. With the widespread use of combination antiretroviral therapy (cART), the incidence of HAND has declined. However, HAND is still an important complication of HIV, which not only affects the quality of life of patients but also affects their adherence to HIV treatment. Its diagnosis mainly relies on neurocognitive tests, which have a certain degree of subjectivity, making it difficult to diagnose and classify HAND accurately, and there is an urgent need to explore more sensitive biomarkers. Multimodal brain imaging has seen a surge in recent years with simultaneous EEG-fMRI being at the forefront of cognitive multimodal neuroimaging. It is a complementary fusion technique that effectively combines the high spatial resolution of fMRI with the high temporal resolution of EEG, compensating for the shortcomings of a single technique and providing a new method for studying cognitive function. It is expected to reveal the underlying mechanisms of HAND and provide high spatiotemporal warning biomarkers of HAND, which will provide a new perspective for the early diagnosis and treatment of HAND and contribute to the improvement of patient prognosis.

The prefrontal cortex, but not the medial temporal lobe, is associated with episodic memory in middle-aged persons with HIV

OBJECTIVE

Identifying persons with HIV (PWH) at increased risk for Alzheimer's disease (AD) is complicated because memory deficits are common in HIV-associated neurocognitive disorders (HAND) and a defining feature of amnestic mild cognitive impairment (aMCI; a precursor to AD). Recognition memory deficits may be useful in differentiating these etiologies. Therefore, neuroimaging correlates of different memory deficits (i.e., recall, recognition) and their longitudinal trajectories in PWH were examined.

DESIGN

We examined 92 PWH from the CHARTER Program, ages 45-68, without severe comorbid conditions, who received baseline structural MRI and baseline and longitudinal neuropsychological testing. Linear and logistic regression examined neuroanatomical correlates (i.e., cortical thickness and volumes of regions associated with HAND and/or AD) of memory performance at baseline and multilevel modeling examined neuroanatomical correlates of memory decline (average follow-up = 6.5 years).

RESULTS

At baseline, thinner pars opercularis cortex was associated with impaired recognition (p = 0.012; p = 0.060 after correcting for multiple comparisons). Worse delayed recall was associated with thinner pars opercularis (p = 0.001) and thinner rostral middle frontal cortex (p = 0.006) cross sectionally even after correcting for multiple comparisons. Delayed recall and recognition were not associated with medial temporal lobe (MTL), basal ganglia, or other prefrontal structures. Recognition impairment was variable over time, and there was little decline in delayed recall. Baseline MTL and prefrontal structures were not associated with delayed recall.

CONCLUSIONS

Episodic memory was associated with prefrontal structures, and MTL and prefrontal structures did not predict memory decline. There was relative stability in memory over time. Findings suggest that episodic memory is more related to frontal structures, rather than encroaching AD pathology, in middle-aged PWH. Additional research should clarify if recognition is useful clinically to differentiate aMCI and HAND.

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

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

The single-cell opioid responses in the context of HIV (SCORCH) consortium

Substance use disorders (SUD) and drug addiction are major threats to public health, impacting not only the millions of individuals struggling with SUD, but also surrounding families and communities. One of the seminal challenges in treating and studying addiction in human populations is the high prevalence of co-morbid conditions, including an increased risk of contracting a human immunodeficiency virus (HIV) infection. Of the ~15 million people who inject drugs globally, 17% are persons with HIV. Conversely, HIV is a risk factor for SUD because chronic pain syndromes, often encountered in persons with HIV, can lead to an increased use of opioid pain medications that in turn can increase the risk for opioid addiction. We hypothesize that SUD and HIV exert shared effects on brain cell types, including adaptations related to neuroplasticity, neurodegeneration, and neuroinflammation. Basic research is needed to refine our understanding of these affected cell types and adaptations. Studying the effects of SUD in the context of HIV at the single-cell level represents a compelling strategy to understand the reciprocal interactions among both conditions, made feasible by the availability of large, extensively-phenotyped human brain tissue collections that have been amassed by the Neuro-HIV research community. In addition, sophisticated animal models that have been developed for both conditions provide a means to precisely evaluate specific exposures and stages of disease. We propose that single-cell genomics is a uniquely powerful technology to characterize the effects of SUD and HIV in the brain, integrating data from human cohorts and animal models. We have formed the Single-Cell Opioid Responses in the Context of HIV (SCORCH) consortium to carry out this strategy.

Investigating the role of nucleoside reverse transcriptase inhibitors in modulating lipotoxicity: Effects on lipid dynamics stress pathways, and insulin resistance on the function of dopaminergic neurons

Despite decades of advancements in HIV treatment, the persistence of viral reservoirs necessitates lifelong therapy, complicating efforts to fully control the infection. Nucleoside reverse transcriptase inhibitors (NRTIs) remain a cornerstone of HIV treatment, but long-term use is associated with side effects, including lipid metabolism disruption and neurocognitive disorders. There is a gap in understanding the safety of antiretrovirals and their impact on lipid toxicity in the central nervous system. To address this issue, our study investigated the impact of NRTIs, specifically lamivudine and zidovudine, on lipid metabolism and insulin resistance in the SH-SY5Y dopaminergic neuronal cell line. We also compared these effects to those induced by two free fatty acids, palmitic and docosahexaenoic acids. We measured mitochondrial superoxide levels, fatty acid binding proteins 4 and 5, and overall lipid content. Additionally, we assessed insulin resistance by analyzing the phosphorylation of mitogen-activated protein kinases and phosphoinositide 3-kinase, as well as the concentrations of insulin receptor substrate 1 and insulin receptor. The results demonstrated that NRTIs led to reduced fatty acid binding protein 4 levels and lipid content, similar to the effects observed with fatty acids. Moreover, lamivudine and zidovudine increased mitochondrial superoxide levels. Lamivudine also amplified the phosphorylation level of ERK. These findings suggest that NRTIs may contribute to lipotoxicity in dopaminergic neurons, warranting further investigation into their long-term effects on the central nervous system.

Progressive multifocal leukoencephalopathy associated with sphingosine-1-phosphate receptor modulators: A large case series

BACKGROUND

Risk factors for progressive multifocal leukoencephalopathy (PML) associated with sphingosine-1-phosphate receptor (S1PR) modulators are not as well-characterized as for natalizumab. We characterized S1PR modulator-associated PML cases and risk factors for PML using spontaneous adverse event reports.

METHODS

We reviewed case reports from the FDA Adverse Event Reporting System database and the medical literature.

RESULTS

We identified 57 PML cases encompassing all marketed S1PR modulators approved for multiple sclerosis, the majority (n = 53) associated with fingolimod. Ten cases reported a fatal outcome. Length of S1PR modulator exposure (≥18 months) appears to be a robust risk factor for PML. Patient age ≥50 years was identified as a potential risk factor, although this may be the result of several biases. We propose that prior immunosuppressant exposure should be considered as a potential risk factor for further validation. No conclusions could be drawn regarding JC virus serology and lymphopenia severity.

CONCLUSIONS

Spontaneous adverse event reports support the observation that extended S1PR modulator exposure appears to be a robust PML risk factor. As a result, the U.S. Prescribing Information for each product in the S1PR modulator class was updated. Validation of other potential risk factors would support efforts to stratify and mitigate the risk of S1PR modulator-associated PML.

Longitudinal study of cognitive function in people with HIV and toxoplasmic encephalitis or latent toxoplasma infection

BACKGROUND

Neurocognitive impairment (NCI) may occur during and persist even after recovery from HIV-related central nervous system (CNS) co-infections such as toxoplasmic encephalitis (TE). The long-term cognitive effects of TE and latent toxoplomasmic infections (LTI) among persons with HIV (PWH) are unknown. We measured longitudinal effects on neurocognitive functioning in PWH with TE compared to LTI or no toxoplasmal infection.

METHODS

PWH (n = 345) followed in two longitudinal cohort studies underwent comprehensive neurocognitive assessments and an anti- toxoplamic immunoglobulin G (IgG) assay. Participants were classified into one of three groups: TE+ ( n  = 39), LTI+ ( n  = 34), LTI- ( n  = 272). The primary outcome was change in neurocognitive function between baseline and 7-year visit.

RESULTS

The mean age was 48 ± 11 years, mean educational level 13 ± 3 years, and 13% were female. TE+ patients were less likely to have undetectable viral loads (≤50 copies/ml) and had lower absolute CD4 + cell count. The TE+ group had the highest prevalence of NCI globally and in domains of verbal, executive function, learning, recall, working memory, processing speed and motor at baseline and at 7-year follow-up. Changes in longitudinal NC function over 7 years were small and did not differ significantly among all groups, except that speed of information processing improved more in TE+ compared with LTI- participants.

CONCLUSIONS

PWH with a history of TE had cognitive impairment over a broad range of severity at both baseline and last follow-up. Changes in cognition from baseline to last examination in all groups were minimal and did not differ significantly among the groups with the exception of speed of information processing.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Tensor-valued diffusion MRI detects brain microstructural abnormalities in HIV infected individuals with cognitive impairment

Despite advancements, the prevalence of HIV-associated neurocognitive impairment remains at approximately 40%, attributed to factors like pre-cART (combination antiretroviral therapy) irreversible brain injury. People with HIV (PWH) treated with cART do not show significant neurocognitive changes over relatively short follow-up periods. However, quantitative neuroimaging may be able to detect ongoing subtle microstructural changes. In this study, we hypothesized that tensor-valued diffusion encoding metrics would provide greater sensitivity than conventional diffusion tensor imaging (DTI) metrics in detecting HIV-associated brain microstructural injury. We further hypothesized that tensor-valued metrics would exhibit stronger associations with blood markers of neuronal and glial injury, such as neurofilament light chain (NFL) and glial fibrillary acidic protein (GFAP), as well as with cognitive performance. Using MRI at 3T, 24 PWH and 31 healthy controls underwent cross-sectional examination. The results revealed significant variations in tensor-valued diffusion encoding metrics across white matter regions, with associations observed between these metrics, cognitive performance, NFL and GFAP. Moreover, a significant interaction between HIV status and imaging metrics in gray and white matter was observed, particularly impacting total cognitive scores. Of interest, DTI metrics were less likely to be associated with HIV status than tensor-valued diffusion metrics. These findings suggest that tensor-valued diffusion encoding metrics offer heightened sensitivity in detecting subtle changes associated with axonal injury in HIV infection. Longitudinal studies are needed to further evaluate responsiveness of tensor-valued diffusion b-tensor encoding metrics in the contest HIV-associate mild chronic neuroinflammation.

The microbiome diversifies N-acyl lipid pools - including short-chain fatty acid-derived compounds

N-acyl lipids are important mediators of several biological processes including immune function and stress response. To enhance the detection of N-acyl lipids with untargeted mass spectrometry-based metabolomics, we created a reference spectral library retrieving N-acyl lipid patterns from 2,700 public datasets, identifying 851 N-acyl lipids that were detected 356,542 times. 777 are not documented in lipid structural databases, with 18% of these derived from short-chain fatty acids and found in the digestive tract and other organs. Their levels varied with diet, microbial colonization, and in people living with diabetes. We used the library to link microbial N-acyl lipids, including histamine and polyamine conjugates, to HIV status and cognitive impairment. This resource will enhance the annotation of these compounds in future studies to further the understanding of their roles in health and disease and highlight the value of large-scale untargeted metabolomics data for metabolite discovery.