Cerebrovascular Contributions to Neurocognitive Disorders in People Living With HIV

Brain-Derived Neurotrophic Factor (BDNF) is Associated with Self-Reported Cognitive Function in Adults with HIV

Background: People with HIV (PWH) are at risk of developing HIV-associated neurocognitive disorder (HAND) despite receiving combination antiretroviral therapy. Brain-derived neurotrophic factor (BDNF) has been implicated in cognitive function and neuroplasticity, but its role in HIV-related neuroinflammation remains understudied. Methods: This study analyzed data from the CHAMPS study, assessing BDNF serum levels and cognitive function in 140 adults with HIV at baseline. Cognitive function was evaluated using the PROMIS Applied Cognition-Abilities 8-item questionnaire. BDNF levels (pg/ml) were measured using high sensitivity Enzyme-Linked Immunoassay (ELISA) kits. Linear regression analyses were conducted to explore the associations between BDNF levels, cognitive function, and AIDS diagnosis, adjusting for demographic variables. Results: A significant positive association was found between BDNF levels and cognitive function scores in PWH (p = .03). Additionally, PWH with a history of AIDS diagnosis showed significantly lower BDNF levels (p = .02). Other demographic factors did not significantly impact cognitive function or BDNF levels in this cohort. Conclusions: Our results highlight the potential of BDNF as a biomarker for cognitive decline in PWH and suggest its relevance in understanding HAND pathophysiology. Further research is warranted to explore the multifaceted interactions influencing cognitive outcomes in this population and to develop targeted interventions for improving cognitive health in PWH.

The Impact of Cannabis Use on Cognition in People with HIV: Evidence of Function-Dependent Effects and Mechanisms from Clinical and Preclinical Studies

PURPOSE OF REVIEW

Cannabis may have beneficial anti-inflammatory effects in people with HIV (PWH); however, given this population's high burden of persisting neurocognitive impairment (NCI), clinicians are concerned they may be particularly vulnerable to the deleterious effects of cannabis on cognition. Here, we present a systematic scoping review of clinical and preclinical studies evaluating the effects of cannabinoid exposure on cognition in HIV.

RECENT FINDINGS

Results revealed little evidence to support a harmful impact of cannabis use on cognition in HIV, with few eligible preclinical data existing. Furthermore, the beneficial/harmful effects of cannabis use observed on cognition were function-dependent and confounded by several factors (e.g., age, frequency of use). Results are discussed alongside potential mechanisms of cannabis effects on cognition in HIV (e.g., anti-inflammatory), and considerations are outlined for screening PWH that may benefit from cannabis interventions. We further highlight the value of accelerating research discoveries in this area by utilizing translatable cross-species tasks to facilitate comparisons across human and animal work.

First-ever acute ischemic strokes in HIV-infected persons: A case-control study from stroke units

OBJECTIVE

The stroke risk for persons living with human immunodeficiency virus (PLHIVs) doubled compared to uninfected individuals. Stroke-unit (SU)-access, acute reperfusion therapy-use and outcome data on PLHIVs admitted for acute ischemic stroke (AIS) are scarce.

METHODS

AIS patients admitted (01 January 2017 to 31 January 2021) to 10 representative Paris-area SUs were screened retrospectively from the National Hospitalization Database. PLHIVs were compared to age-, initial NIHSS- and sex-matched HIV-uninfected controls (HUCs). Outcome was the 90-day modified Rankin Scale score.

RESULTS

Among 126 PLHIVs with confirmed first-ever AIS, ~80% were admitted outside the thrombolysis-administration window. Despite antiretrovirals, uncontrolled plasma HIV loads exceeded 50 copies/mL (26% of all PLHIVs; 38% of those ≤55 years). PLHIVs' stroke causes by decreasing frequency were large artery atherosclerosis (LAA), undetermined, other cause, cerebral small-vessel disease (CSVD) or cardioembolism. No stroke etiology was associated with HIV duration or detectable HIVemia. MRI revealed previously unknown AIS in one in three PLHIVs, twice the HUC rate (p = 0.006). Neither group had optimally controlled modifiable cardiovascular risk factors (CVRFs): 20%-30% without specific hypertension, diabetes, and/or dyslipidemia treatments. Their stroke outcomes were comparable. Multivariable analyses retained good prognosis associated solely with initial NIHSS or reperfusion therapy. Older age and hypertension were associated with CSVD/LAA for all PLHIVs. Standard neurovascular care and reperfusion therapy were well-tolerated.

INTERPRETATION

The high uncontrolled HIV-infection rate and suboptimal CVRF treatment support heightened vigilance to counter suboptimal HIV suppression and antiretroviral adherence, and improve CVRF prevention, mainly for younger PLHIVs. Those preventive, routine measures could lower PLHIVs' AIS risk.

Age-Accelerated Increase of White Matter Hyperintensity Volumes Is Exacerbated by Heavy Alcohol Use in People Living With HIV

BACKGROUND

Antiretroviral treatment has enabled people living with HIV infection to have a near-normal life span. With longevity comes opportunities for engaging in risky behavior, including initiation of excessive drinking. Given that both HIV infection and alcohol use disorder (AUD) can disrupt brain white matter integrity, we questioned whether HIV infection, even if successfully treated, or AUD alone results in signs of accelerated white matter aging and whether HIV+AUD comorbidity further accelerates brain aging.

METHODS

Longitudinal magnetic resonance imaging-FLAIR data were acquired over a 15-year period from 179 control individuals, 204 participants with AUD, 70 participants with HIV, and 75 participants with comorbid HIV+AUD. White matter hyperintensity (WMH) volumes were quantified and localized, and their functional relevance was examined with cognitive and motor testing.

RESULTS

The 3 diagnostic groups each had larger WMH volumes than the control group. Although all 4 groups exhibited accelerating volume increases with aging, only the HIV groups showed faster WMH enlargement than control individuals; the comorbid group showed faster acceleration than the HIV-only group. Sex and HIV infection length, but not viral suppression status, moderated acceleration. Correlations emerged between WMH volumes and attention/working memory and executive function scores of the AUD and HIV groups and between WMH volumes and motor skills in the 3 diagnostic groups.

CONCLUSIONS

Even treated HIV can show accelerated aging, possibly from treatment sequelae or legacy effects, and notably from AUD comorbidity. WMH volumes may be especially relevant for tracking HIV and AUD brain health because each condition is associated with liability for hypertensive processes, for which WMHs are considered a marker.

Vascular injury markers associated with cognitive impairment in people with HIV on suppressive antiretroviral therapy

OBJECTIVE

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) remain prevalent despite viral suppression on antiretroviral therapy (ART). Vascular disease contributes to HAND, but peripheral markers that distinguish vascular cognitive impairment (VCI) from HIV-related etiologies remain unclear.

DESIGN

Cross-sectional study of vascular injury, inflammation, and central nervous system (CNS) injury markers in relation to HAND.

METHODS

Vascular injury (VCAM-1, ICAM-1, CRP), inflammation (IFN-γ, IL-1β, IL-6, IL-8, IL-15, IP-10, MCP-1, VEGF-A), and CNS injury (NFL, total Tau, GFAP, YKL-40) markers were measured in plasma and CSF from 248 individuals (143 HIV+ on suppressive ART and 105 HIV- controls).

RESULTS

Median age was 53 years, median CD4 + cell count, and duration of HIV infection were 505 cells/μl and 16 years, respectively. Vascular injury, inflammation, and CNS injury markers were increased in HIV+ compared with HIV- individuals ( P < 0.05). HAND was associated with increased plasma VCAM-1, ICAM-1, and YKL-40 ( P  < 0.01) and vascular disease ( P  = 0.004). In contrast, inflammation markers had no significant association with HAND. Vascular injury markers were associated with lower neurocognitive T scores in age-adjusted models ( P  < 0.01). Furthermore, plasma VCAM-1 correlated with NFL ( r  = 0.29, P  = 0.003). Biomarker clustering separated HAND into three clusters: two clusters with high prevalence of vascular disease, elevated VCAM-1 and NFL, and distinctive inflammation profiles (CRP/ICAM-1/YKL-40 or IL-6/IL-8/IL-15/MCP-1), and one cluster with no distinctive biomarker elevations.

CONCLUSIONS

Vascular injury markers are more closely related to HAND and CNS injury in PWH on suppressive ART than inflammation markers and may help to distinguish relative contributions of VCI to HAND.

Low levels of peripheral blood activated and senescent T cells characterize people with HIV-1-associated neurocognitive disorders

Background

HIV infection induces a 75% increase in the risk of developing neurocognitive impairment (NCI), which has been linked to immune activation. We therefore looked for immune activation markers correlating with NCI.

Method

Sixty-five people aged 55-70 years living with controlled HIV-1 infection were enrolled in the study and their neurocognitive ability was assessed according to the Frascati criteria. Fifty-nine markers of T4 cell, T8 cell, NK cell, and monocyte activation, inflammation and endothelial activation were measured in their peripheral blood. White matter hyperintensities (WMH) were identified by magnetic resonance imaging. Double hierarchical clustering was performed for the activation markers and 240 patients including the 65 whose neurocognitive performance had been evaluated.

Results

Thirty-eight percent of volunteers presented NCI. Twenty-four percent of them were asymptomatic and fourteen percent had a mild disorder. Strikingly, activated (HLA-DR+) as well as senescent (CD57+CD28-CD27±) T4 cells and T8 cells were less prevalent in the peripheral blood of participants with NCI than in participants without the disorder. Accordingly, the percentage of HLA-DR+ T4 cells was lower in volunteers with periventricular and deep WMH. The double hierarchical clustering unveiled six different immune activation profiles. The neurocognitive performances of participants with two of these six profiles were poor. Here again, these two profiles were characterized by a low level of T4 and T8 cell activation and senescence.

Conclusion

Our observation of low circulating levels of activated and senescent T cells in HIV-1 patients with NCI raises the interesting hypothesis that these lymphocytes may be recruited into the central nervous system.

Vascular injury markers associated with cognitive impairment in people with HIV on suppressive antiretroviral therapy

Objective

Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) remain prevalent despite viral suppression on antiretroviral therapy (ART). Vascular disease contributes to HAND, but peripheral markers that distinguish vascular cognitive impairment (VCI) from HIV-related etiologies remain unclear.

Design

Cross-sectional study of vascular injury, inflammation, and central nervous system (CNS) injury markers in relation to HAND.

Methods

Vascular injury (VCAM-1, ICAM-1, CRP), inflammation (IFN-γ, IL-1β, IL-6, IL-8, IL-15, IP-10, MCP-1, VEGF-A), and CNS injury (NFL, total Tau, GFAP, YKL-40) markers were measured in plasma and CSF from 248 individuals (143 HIV+ on suppressive ART and 105 HIV- controls).

Results

Median age was 53 years, median CD4 count, and duration of HIV infection were 505 cells/μl and 16 years, respectively. Vascular injury, inflammation, and CNS injury markers were increased in HIV+ compared with HIV- individuals (p<0.05). HAND was associated with increased plasma VCAM-1, ICAM-1, and YKL-40 (p<0.01) and vascular disease (p=0.004). In contrast, inflammation markers had no significant association with HAND. Vascular injury markers were associated with lower neurocognitive T scores in age-adjusted models (p<0.01). Furthermore, plasma VCAM-1 correlated with NFL (r=0.29, p=0.003). Biomarker clustering separated HAND into three clusters: two clusters with high prevalence of vascular disease, elevated VCAM-1 and NFL, and distinctive inflammation profiles (CRP/ICAM-1/YKL-40 or IL-6/IL-8/IL-15/MCP-1), and one cluster with no distinctive biomarker elevations.

Conclusions

Vascular injury markers are more closely related to HAND and CNS injury in PWH on suppressive ART than inflammation markers and may help to distinguish relative contributions of VCI to HAND.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Do correlates of white matter features differ between older men and women living with human immunodeficiency virus?

OBJECTIVE

Given estrogen's role in human immunodeficiency virus (HIV) disease progression and the higher rates of neurocognitive decline in affected women, the purpose of this study was to assess whether the relationship of white matter features and reproductive hormone levels differed between men versus women (sex as a moderator), controlling for selected cardiometabolic risk factors, HIV-related health indicators, and demographics in an aging population of persons living with HIV (PLWH).

METHODS

Older PLWH (50 y and older; 44 women and 35 men; mean ± SD age, 59.8 ± 0.6 y; 55.7% women; 72.2% non-Hispanic Black) participated in a cross-sectional study involving a fasting blood draw and a demographic survey (visit 1) and a magnetic resonance imaging scan (visit 2) to determine white matter volume and white matter hyperintensity (WMH) volume. Associations between reproductive hormones (follicle-stimulating hormone [FSH], estradiol, testosterone, dehydroepiandrosterone sulfate [DHEA-S]) and white matter features were assessed in linear regression models. Covariates were age, body mass index, hypertension, diabetes, dyslipidemia, current smoking status, CD4 count, and cranial size.

RESULTS

For white matter volume, a sexually dimorphic interaction was seen for DHEA-S (B = 21.23; P = 0.012) and observed for FSH (B = -22.97, P = 0.08) with a trend for significance after controlling for risk factors. In women, higher white matter volume was associated with higher DHEA-S (B = 13.89, P = 0.017) and lower FSH (B = 23.58, P = 0.01). No hormone associations were shown in men for white matter volume. For WMH volume, no significant interaction effects between sex and reproductive hormones were identified. For WMH, sex did not predict associations with reproductive hormones after controlling for risk factors.

CONCLUSIONS

Although sexually dimorphic interactions of reproductive hormones and total white matter volume were demonstrated, our study findings do not support a role for sex-based differences in reproductive hormones as predictive correlates of WMH in a small sample of older PLWH.

Application of Diffusion Tensor Imaging (DTI) in the Diagnosis of HIV-Associated Neurocognitive Disorder (HAND): A Meta-Analysis and a System Review

Background

The patients with HIV-associated neurocognitive disorder (HAND) are often accompanied by white matter structure damage. Diffusion tensor imaging (DTI) is an important tool to detect white matter structural damage. However, the changes in DTI values reported in many studies are diverse in different white matter fiber tracts and brain regions.

Purpose

Our research is dedicated to evaluating the consistency and difference of the correlation between HAND and DTI measures in different studies. Additionally, the value of DTI in HAND evaluation is used to obtain consensus and independent conclusions between studies.

Methods

We searched PubMed and Web of Science to collect relevant studies using DTI for the diagnosis of HAND. After screening and evaluating the search results, meta-analysis is used for quantitative research on data. Articles that cannot collect data but meet the research relevance will be subjected to a system review.

Results

The meta-analysis shows that the HAND group has lower fractional anisotropy (standardized mean difference = −0.57 p < 0.0001) and higher mean diffusivity (standardized mean difference = 0.04 p < 0.0001) than the healthy control group in corpus callosum. In other white matter fibers, we found similar changes in fractional anisotropy (standardized mean difference = −1.18 p < 0.0001) and mean diffusivity (standardized mean difference = 0.69 p < 0.0001). However, the heterogeneity (represented by I²) between the studies is high (in corpus callosum 94, 88%, in other matter fibers 95, 81%). After subgroup analysis, the heterogeneity is obtained as 19.5, 40.7% (FA, MD in corpus callosum) and 0, 0% (FA, MD among other white matter fibers).

Conclusion

The changes in white matter fibers in patients with HAND are statistically significant at the observation level of DTI compared with healthy people. The differences between the studies are mainly derived from demographics, start and maintenance time of antiretroviral therapy, differences in nadir CD4+T cells, and the use of different neurocognitive function scales. As an effective method to detect the changes in white matter fibers, DTI is of great significance for the diagnosis of HAND, but there are still some shortcomings. In the absence of neurocognitive function scales, independent diagnosis remains difficult.

Systematic Review Registration:https://inplasy.com/inplasy-2021-10-0079/.