HIV integration in the human brain is linked to microglial activation and 3D genome remodeling.

To explore genome organization and function in the HIV-infected brain, we applied single-nuclei transcriptomics, cell-type-specific chromosomal conformation mapping, and viral integration site sequencing (IS-seq) to frontal cortex from individuals with encephalitis (HIVE) and without (HIV+). Derepressive changes in 3D genomic compartment structures in HIVE microglia were linked to the transcriptional activation of interferon (IFN) signaling and cell migratory pathways, while transcriptional downregulation and repressive compartmentalization of neuronal health and signaling genes occurred in both HIVE and HIV+ microglia. IS-seq recovered 1,221 brain integration sites showing distinct genomic patterns compared with peripheral lymphocytes, with enrichment for sequences newly mobilized into a permissive chromatin environment after infection. Viral transcription occurred in a subset of highly activated microglia comprising 0.33% of all nuclei in HIVE brain. Our findings point to disrupted microglia-neuronal interactions in HIV and link retroviral integration to remodeling of the microglial 3D genome during infection.

Longitudinal analysis of CSF HIV RNA in untreated people with HIV: Identification of CSF controllers.

Interindividual variation of human immunodeficiency virus (HIV) RNA setpoint in cerebrospinal fluid (CSF) and its determinants are poorly understood, but relevant for HIV neuropathology, brain reservoirs, viral escape, and reseeding after antiretroviral interruptions. Longitudinal multicentric study on demographic, clinical, and laboratory correlates of CSF HIV RNA in 2000 follow-up visits from 597 people with HIV (PWH) off antiretroviral therapy (ART) and with plasma HIV RNA > the lower limit of quantification (LLQ). Factors associated with CSF control (CSFC; CSF HIV RNA < LLQ while plasma HIV RNA > LLQ) and with CSF/plasma discordance (CSF > plasma HIV RNA > LLQ) were also assessed through mixed-effects models. Posthoc and sensitivity analyses were performed for persistent CSFC and ART-naïve participants, respectively. Over a median follow-up of 2.1 years, CSF HIV RNA was associated with CD4+ and CD8+ T cells, CSF leukocytes, blood-brain barrier (BBB) integrity, biomarkers of iron and lipid metabolism, serum globulins, past exposure to lamivudine, and plasma HIV RNA (model p < 0.0001). CSFC (persistent in 7.7% over 3 years) and CSF/plasma discordance (persistent in <0.01% over 1 year) were variably associated with the same parameters (model p < 0.001). Sensitivity analyses confirmed most of the previous associations in participants never exposed to ART. Persistent CSFC was associated with higher CD4+ T-cell count nadir (p < 0.001), lower serum globulins (p = 0.003), and lower CSF leukocytes (p < 0.001). Without ART, one in 13 PWH had persistently undetectable CSF HIV RNA, while persistent CSF/plasma discordance was extremely rare over years. Immune responses, inflammation, BBB permeability, and iron and lipid metabolism were all associated with HIV replication in CSF.

Twelve-year neurocognitive decline in HIV is associated with comorbidities, not age: a CHARTER study.

Modern antiretroviral therapy (ART) has increased longevity of people with HIV and shifted the age distribution of the HIV pandemic upward toward that of the general population. This positive development has also led to concerns about premature and/or accelerated neurocognitive and physical ageing due to the combined effects of chronic HIV, accumulating comorbidities, adverse effects or possible toxicities of ART and biological ageing. Here we present results of comprehensive assessments over 12 years of 402 people with HIV in the CNS HIV ART Effects Research (CHARTER) programme, who at follow-up were composed of younger (<60 years) and older (≥60 years) subgroups. Over the 12 years, ART use and viral suppression increased in both subgroups as did systemic and psychiatric comorbidities; participants in both subgroups also evidenced neurocognitive decline beyond what is expected in typical ageing. Contrary to expectations, all these adverse effects were comparable in the younger and older CHARTER subgroups, and unrelated to chronological age. Neurocognitive decline was unrelated to HIV disease or treatment characteristics but was significantly predicted by the presence of comorbid conditions, specifically diabetes, hypertension, chronic pulmonary disease, frailty, neuropathic pain, depression and lifetime history of cannabis use disorder. These results are not consistent with premature or accelerated neurocognitive ageing due to HIV itself but suggest important indirect effects of multiple, potentially treatable comorbidities that are more common among people with HIV than in the general population. Good medical management of HIV disease did not prevent these adverse outcomes, and increased attention to a range of comorbid conditions in people with HIV may be warranted in their care.

Pathology-based brain arterial disease phenotypes and their radiographic correlates.

INTRODUCTION: Brain arterial diseases, including atherosclerosis, vasculitis, and dissections, are major contributors to cerebrovascular morbidity and mortality worldwide. These diseases not only increase the risk of stroke but also play a significant role in neurodegeneration and dementia. Clear and unambiguous terminology and classification of brain arterial disease phenotypes is crucial for research and clinical practice. MATERIAL AND METHODS: This review aims to summarize and harmonize the terminology used for brain large and small arterial phenotypes based on pathology studies and relate them to imaging phenotypes used in medical research and clinical practice. CONCLUSIONS AND RESULTS: Arteriosclerosis refers to hardening of the arteries but does not specify the underlying etiology. Specific terms such as atherosclerosis, calcification, or non-atherosclerotic fibroplasia are preferred. Atherosclerosis is defined pathologically by an atheroma. Other brain arterial pathologies occur and should be distinguished from atherosclerosis given therapeutic implications. On brain imaging, intracranial arterial luminal stenosis is usually attributed to atherosclerosis in the presence of atherosclerotic risk factors but advanced high-resolution arterial wall imaging has the potential to more accurately identify the underlying pathology. Regarding small vessel disease, arteriosclerosis is ambiguous and arteriolosclerosis is often used to denote the involvement of arterioles rather than arteries. Lipohyalinosis is sometimes used synonymously with arteriolosclerosis, but less accurately describes this common small vessel thickening which uncommonly shows lipid. Specific measures of small vessel wall thickness, the relationship to the lumen as well as changes in the layer composition might convey objective, measurable data regarding the status of brain small vessels.

Biotypes of Central Nervous System Complications in People With Human Immunodeficiency Virus: Virology, Immunology, and Neuropathology.

Despite viral suppression with antiretroviral therapy (ART), people with human immunodeficiency virus (HIV) continue to experience central nervous system (CNS) complications, primarily in the form of mild cognitive impairment and mental health disorders (eg, depression, anxiety, other neuropsychiatric problems). The multifactorial pathogenesis and heterogeneity of mechanisms likely underlying CNS complications must be addressed in the development of preventive interventions and effective treatments. The biotyping approach has previously been useful to define phenotypes of other CNS diseases based on underlying mechanisms and could be translated to the field of neuroHIV. The purpose of the Biotype Workshop series, and the Virology, Immunology and Neuropathology Working Group in particular, is to capitalize on current and new technologies and guide future research efforts using the wealth of available immunological, virologic, and neuropathological data collected from people with HIV on and off ART.

Predictors of hippocampal tauopathy in people with and at risk for human immunodeficiency virus infection.

Combination antiretroviral therapy (cART) has extended lifespans of people living with HIV (PWH), increasing both the risk for age-related neuropathologies and the importance of distinguishing effects of HIV and its comorbidities from neurodegenerative disorders. The accumulation of hyperphosphorylated tau (p-tau) in hippocampus is a common degenerative change, with specific patterns of hippocampal subfield vulnerability observed in different disease contexts. Currently, associations between chronic HIV, its comorbidities, and p-tau burden and distribution in the hippocampus are unexplored. We used immunohistochemistry with antibody AT8 to analyze hippocampal p-tau in brain tissues of PWH (n = 71) and HIV negative controls (n = 25), for whom comprehensive clinical data were available. Using a morphology-based neuroanatomical segmentation protocol, we annotated digital slide images to measure percentage p-tau areas in the hippocampus and its subfields. Factors predicting p-tau burden and distribution were identified in univariate analyses, and those with significance at p ≤ 0.100 were advanced to multivariable regression. The patient sample had a mean age of 61.5 years. Age predicted overall hippocampal p-tau burden. Subfield p-tau predictors were for Cornu Ammonis (CA)1, age; for CA2 and subiculum, seizure history; for CA3, seizure history and head trauma; and for CA4/dentate, history of hepatitis C virus (HCV) infection. In this autopsy sample, hippocampal p-tau burden and distribution were not predicted by HIV, viral load, or immunologic status, with viral effects limited to associations between HCV and CA4/dentate vulnerability. Hippocampal p-tau pathologies in cART-era PWH appear to reflect age and comorbidities, but not direct effects of HIV infection.

Histopathologic brain age estimation via multiple instance learning.

Understanding age acceleration, the discordance between biological and chronological age, in the brain can reveal mechanistic insights into normal physiology as well as elucidate pathological determinants of age-related functional decline and identify early disease changes in the context of Alzheimer's and other disorders. Histopathological whole slide images provide a wealth of pathologic data on the cellular level that can be leveraged to build deep learning models to assess age acceleration. Here, we used a collection of digitized human post-mortem hippocampal sections to develop a histological brain age estimation model. Our model predicted brain age within a mean absolute error of 5.45 ± 0.22 years, with attention weights corresponding to neuroanatomical regions vulnerable to age-related changes. We found that histopathologic brain age acceleration had significant associations with clinical and pathologic outcomes that were not found with epigenetic based measures. Our results indicate that histopathologic brain age is a powerful, independent metric for understanding factors that contribute to brain aging.

Sphingolipid and Phospholipid Levels Are Altered in Human Brain in Chorea-Acanthocytosis.

BACKGROUND: Chorea-acanthocytosis (ChAc) is associated with mutations of VPS13A, which encodes for chorein, a protein implicated in lipid transport at intracellular membrane contact sites. OBJECTIVES: The goal of this study was to establish the lipidomic profile of patients with ChAc. METHODS: We analyzed 593 lipid species in the caudate nucleus (CN), putamen, and dorsolateral prefrontal cortex (DLPFC) from postmortem tissues of four patients with ChAc and six patients without ChAc. RESULTS: We found increased levels of bis(monoacylglycerol)phosphate, sulfatide, lysophosphatidylserine, and phosphatidylcholine ether in the CN and putamen, but not in the DLPFC, of patients with ChAc. Phosphatidylserine and monoacylglycerol were increased in the CN and N-acyl phosphatidylserine in the putamen. N-acyl serine was decreased in the CN and DLPFC, whereas lysophosphatidylinositol was decreased in the DLPFC. CONCLUSIONS: We present the first evidence of altered sphingolipid and phospholipid levels in the brains of patients with ChAc. Our observations are congruent with recent findings in cellular and animal models, and implicate defects of lipid processing in VPS13A disease pathophysiology. © 2023 International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Age, cognitive status, and accuracy of ADL self-reports in adults living with HIV.

Determination of functional capacity in cognitively impaired persons living with HIV (PLHIV) is pivotal to the accurate diagnosis of HIV-associated neurocognitive disorders (HAND). Functional data is typically collected through self-report. Reliability concerns arise with memory and executive functioning impairments, which could compromise the integrity of self-report and result in inaccurate HAND diagnoses. The current study tested the accuracy of older PLHIV functional reports through examination of concordance rates between self-report and caregiver's (CG) report. Cross-sectional cognitive, mood, and functional status data were sampled from the Manhattan HIV Brain Bank. Participants and caregivers independently completed an Activities of Daily Living (ADL) questionnaire, producing 78 participant-caregiver dyads. Functional report concordance was operationalized by calculating differences between participant and CG ADL total scores. Assessment pairs differing by 2 or more points were considered to be discordant. Analyses revealed that one-third of the patient sample was discordant in the ADL report. ANOVA revealed that PLHIV overestimating their functional impairments, were significantly older, more educated, and more depressed than other participants. Global cognitive functioning was not associated with concordance. Thus, the majority of PLHIV were consistent with their caregivers' ADL report, and older age and increased depressive symptomatology, but not cognitive status, were factors associated with discordance.

Higher buccal mitochondrial DNA and mitochondrial common deletion number are associated with markers of neurodegeneration and inflammation in cerebrospinal fluid.

Human immunodeficiency virus (HIV) infection is potentially associated with premature aging, but demonstrating this is difficult due to a lack of reliable biomarkers. The mitochondrial (mt) DNA "common deletion" mutation (mtCDM) is a 4977-bp deletion associated with aging and neurodegenerative diseases. We examined how mtDNA and mtCDM correlate with markers of neurodegeneration and inflammation in people with and without HIV (PWH and PWOH). Data from 149 adults were combined from two projects involving PWH (n = 124) and PWOH (n = 25). We measured buccal mtDNA and mtCDM by digital droplet PCR and compared them to disease and demographic characteristics and soluble biomarkers in cerebrospinal fluid (CSF) and blood measured by immunoassay. Participants had a median age of 52 years, with 53% white and 81% men. Median mtDNA level was 1,332 copies/cell (IQR 1,201-1,493) and median mtCDM level was 0.36 copies × 102/cell (IQR 0.31-0.42); both were higher in PWH. In the best model adjusting for HIV status and demographics, higher mtDNA levels were associated with higher CSF amyloid-ß 1-42 and 8-hydroxy-2'-deoxyguanosine and higher mtCDM levels were associated with higher plasma soluble tumor necrosis factor receptor II. The differences in mtDNA markers between PWH and PWOH support potential premature aging in PWH. Our findings suggest mtDNA changes in oral tissues may reflect CNS processes, allowing the use of inexpensive and easily accessible buccal biospecimens as a screening tool for CSF inflammation and neurodegeneration. Confirmatory and mechanistic studies on mt genome alterations by HIV and ART may identify interventions to prevent or treat neurodegenerative complications.

Low Neuroactive Steroids Identifies a Biological Subtype of Depression in Adults with Human Immunodeficiency Virus on Suppressive Antiretroviral Therapy.

BACKGROUND: The prevalence and mortality risk of depression in people with human immunodeficiency virus (HIV) infection receiving antiretroviral therapy (ART) is higher than in the general population, yet biomarkers for therapeutic targeting are unknown. In the current study, we aimed to identify plasma metabolites associated with depressive symptoms in people with HIV receiving ART. METHODS: This is a prospective study of ART-treated HIV-infected adults with or without depressive symptoms assessed using longitudinal Beck Depression Inventory scores. Plasma metabolite profiling was performed in 2 independent cohorts (total n = 99) using liquid and gas chromatography and tandem mass spectrometry. RESULTS: Participants with depressive symptoms had lower neuroactive steroids (dehydroepiandrosterone sulfate [DHEA-S], androstenediols, and pregnenolone sulfate) compared with those without depressive symptoms. The cortisol/DHEA-S ratio, an indicator of hypothalamic-pituitary-adrenal axis imbalance, was associated with depressive symptoms (P < .01) because of low DHEA-S levels, whereas cortisol was similar between groups. The odds of having depressive symptoms increased with higher cortisol/DHEA-S ratios (adjusted odds ratio, 2.5 per 1-unit increase in z score; 95% confidence interval, 1.3-4.7), independent of age and sex. The kynurenine-to-tryptophan ratio showed no significant associations. CONCLUSIONS: These findings suggest that altered neuroactive steroid metabolism may contribute to the pathophysiological mechanisms of depression in ART-treated HIV-infected adults, representing a potential biological pathway for therapeutic targeting.

Paresthesia Predicts Increased Risk of Distal Neuropathic Pain in Older People with HIV-Associated Sensory Polyneuropathy.

OBJECTIVE: Distal sensory polyneuropathy (DSP) is a disabling consequence of human immunodeficiency virus (HIV), leading to poor quality of life and more frequent falls in older age. Neuropathic pain and paresthesia are prevalent symptoms; however, there are currently no known curative treatments and the longitudinal course of pain in HIV-associated DSP is poorly characterized. METHODS: This was a prospective longitudinal study of 265 people with HIV (PWH) enrolled in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) study with baseline and 12-year follow-up evaluations. Since pain and paresthesia are highly correlated, statistical decomposition was used to separate the two symptoms at baseline. Multivariable logistic regression analyses of decomposed variables were used to determine the effects of neuropathy symptoms at baseline on presence and worsening of distal neuropathic pain at 12-year follow-up, adjusted for covariates. RESULTS: Mean age was 56 ± 8 years, and 21% were female at follow-up. Nearly the entire cohort (96%) was on antiretroviral therapy (ART), and 82% had suppressed (≤50 copies/mL) plasma viral loads at follow-up. Of those with pain at follow-up (n = 100), 23% had paresthesia at the initial visit. Decomposed paresthesia at baseline increased the risk of pain at follow-up (odds ratio [OR] 1.56; 95% confidence interval [CI] 1.18, 2.07), and decomposed pain at baseline predicted a higher frequency of pain at follow-up (OR 1.96 [95% CI 1.51, 2.58]). CONCLUSIONS: Paresthesias are a clinically significant predictor of incident pain at follow-up among aging PWH with DSP. Development of new therapies to encourage neuroregeneration might take advantage of this finding to choose individuals likely to benefit from treatment preventing incident pain.

Characteristics of Motor Dysfunction in Longstanding Human Immunodeficiency Virus.

BACKGROUND: Cognitive dysfunction in human immunodeficiency virus (HIV) has decreased, but milder forms of HIV-associated neurocognitive disorders (HAND) persist along with motor dysfunction. The HIV Motor Scale (HMS) is a validated tool that captures motor abnormalities on routine neurologic examination and which is associated with cognitive impairment in HIV. In this study, we applied a modified HMS (MHMS) to a nationwide cohort of people with longstanding HIV to characterize and understand the factors contributing to motor dysfunction. METHODS: The National NeuroAIDS Tissue Consortium is a nationwide longitudinal cohort study. Participants undergo regular assessments including neurological examination, neuropsychological testing, and immunovirologic data collection. Data from examinations were used to calculate the MHMS score, which was then correlated with history of AIDS-related central nervous system (CNS) disorders (ARCD; eg, prior CNS opportunistic infection), cerebrovascular disease (CVD), and HAND. RESULTS: Sixty-nine percent of participants showed an abnormality on the MHMS, with 27% classified as severe. Results did not vary based on demographic or immunologic variables. The most common abnormalities seen were gait (54%), followed by coordination (39%) and strength (25%), and these commonly co-occurred. CVD (P = .02), history of ARCD (P = .001), and HAND (P = .001) were all associated with higher (ie, worse) HMS in univariate analyses; CVD and ARCD persisted in multivariate analyses. CVD was also marginally associated with symptomatic HAND. CONCLUSIONS: Complex motor dysfunction remains common in HIV and is associated with CVD, ARCD, and to a lesser extent, HAND. Future studies are needed to understand the longitudinal trajectory of HIV-associated motor dysfunction, its neural substrates, and impact on quality of life.

Coronaviruses and the central nervous system.

Seven coronavirus (CoV) species are known human pathogens: the epidemic viruses SARS-CoV, SARS-CoV-2, and MERS-CoV and those continuously circulating in human populations since initial isolation: HCoV-OC43, HCoV-229E, HCoV-HKU1, and HCoV-NL63. All have associations with human central nervous system (CNS) dysfunction. In infants and young children, the most common CNS phenomena are febrile seizures; in adults, non-focal abnormalities that may be either neurologic or constitutional. Neurotropism and neurovirulence are dependent in part on CNS expression of cell surface receptors mediating viral entry, and host immune response. In adults, CNS receptors for epidemic viruses are largely expressed on brain vasculature, whereas receptors for less pathogenic viruses are present in vasculature, brain parenchyma, and olfactory neuroepithelium, dependent upon viral species. Human coronaviruses can infect circulating mononuclear cells, but meningoencephalitis is rare. Well-documented human neuropathologies are infrequent and, for SARS, MERS, and COVID-19, can entail cerebrovascular accidents originating extrinsically to brain. There is evidence of neuronal infection in the absence of inflammatory infiltrates with SARS-CoV, and CSF studies of rare patients with seizures have demonstrated virus but no pleocytosis. In contrast to human disease, animal models of neuropathogenesis are well developed, and pathologies including demyelination, neuronal necrosis, and meningoencephalitis are seen with both native CoVs as well as human CoVs inoculated into nasal cavities or brain. This review covers basic CoV biology pertinent to CNS disease; the spectrum of clinical abnormalities encountered in infants, children, and adults; and the evidence for CoV infection of human brain, with reference to pertinent animal models of neuropathogenesis.

Caspase-1 Activation Is Related With HIV-Associated Atherosclerosis in an HIV Transgenic Mouse Model and HIV Patient Cohort.

OBJECTIVE: Atherosclerotic cardiovascular disease (ASCVD) is an increasing cause of morbidity and mortality in people with HIV since the introduction of combination antiretroviral therapy. Despite recent advances in our understanding of HIV ASCVD, controversy still exists on whether this increased risk of ASCVD is due to chronic HIV infection or other risk factors. Mounting biomarker studies indicate a role of monocyte/macrophage activation in HIV ASCVD; however, little is known about the mechanisms through which HIV infection mediates monocyte/macrophage activation in such a way as to engender accelerated atherogenesis. Here, we experimentally investigated whether HIV expression is sufficient to accelerate atherosclerosis and evaluated the role of caspase-1 activation in monocytes/macrophages in HIV ASCVD. Approach and Results: We crossed a well-characterized HIV mouse model, Tg26 mice, which transgenically expresses HIV-1, with ApoE-/- mice to promote atherogenic conditions (Tg26+/-/ApoE-/-). Tg26+/-/ApoE-/- have accelerated atherosclerosis with increased caspase-1 pathway activation in inflammatory monocytes and atherosclerotic vasculature compared with ApoE-/-. Using a well-characterized cohort of people with HIV and tissue-banked aortic plaques, we documented that serum IL (interleukin)-18 was higher in people with HIV compared with non-HIV-infected controls, and in patients with plaques, IL-18 levels correlated with monocyte/macrophage activation markers and noncalcified inflammatory plaques. In autopsy-derived aortic plaques, caspase-1+ cells and CD (clusters of differentiation) 163+ macrophages correlated. CONCLUSIONS: These data demonstrate that expression of HIV is sufficient to accelerate atherogenesis. Further, it highlights the importance of caspase-1 and monocyte/macrophage activation in HIV atherogenesis and the potential of Tg26+/-/ApoE-/- as a tool for mechanistic studies of HIV ASCVD.

Use of Neuroimaging to Inform Optimal Neurocognitive Criteria for Detecting HIV-Associated Brain Abnormalities.

OBJECTIVE: Frascati international research criteria for HIV-associated neurocognitive disorders (HAND) are controversial; some investigators have argued that Frascati criteria are too liberal, resulting in a high false positive rate. Meyer et al. recommended more conservative revisions to HAND criteria, including exploring other commonly used methodologies for neurocognitive impairment (NCI) in HIV including the global deficit score (GDS). This study compares NCI classifications by Frascati, Meyer, and GDS methods, in relation to neuroimaging markers of brain integrity in HIV. METHOD: Two hundred forty-one people living with HIV (PLWH) without current substance use disorder or severe (confounding) comorbid conditions underwent comprehensive neurocognitive testing and brain structural magnetic resonance imaging and magnetic resonance spectroscopy. Participants were classified using Frascati criteria versus Meyer criteria: concordant unimpaired [Frascati(Un)/Meyer(Un)], concordant impaired [Frascati(Imp)/Meyer(Imp)], or discordant [Frascati(Imp)/Meyer(Un)] which were impaired via Frascati criteria but unimpaired via Meyer criteria. To investigate the GDS versus Meyer criteria, the same groupings were utilized using GDS criteria instead of Frascati criteria. RESULTS: When examining Frascati versus Meyer criteria, discordant Frascati(Imp)/Meyer(Un) individuals had less cortical gray matter, greater sulcal cerebrospinal fluid volume, and greater evidence of neuroinflammation (i.e., choline) than concordant Frascati(Un)/Meyer(Un) individuals. GDS versus Meyer comparisons indicated that discordant GDS(Imp)/Meyer(Un) individuals had less cortical gray matter and lower levels of energy metabolism (i.e., creatine) than concordant GDS(Un)/Meyer(Un) individuals. In both sets of analyses, the discordant group did not differ from the concordant impaired group on any neuroimaging measure. CONCLUSIONS: The Meyer criteria failed to capture a substantial portion of PLWH with brain abnormalities. These findings support continued use of Frascati or GDS criteria to detect HIV-associated CNS dysfunction.

Relationship Between Brain Arterial Pathology and Neurocognitive Performance Among Individuals With Human Immunodeficiency Virus.

Background: Human immunodeficiency virus-positive (HIV+) individuals have higher rates of cognitive impairment and cerebrovascular disease compared with uninfected populations. We hypothesize that cerebrovascular disease, specifically brain large artery disease, may play a role in HIV-associated neurocognitive disorders (HAND). Methods: Participants (N = 94) in the Manhattan HIV Brain Bank study were followed on average 32 ± 33 months with repeated neuropsychological examinations until death. We used five cognitive domains (motor, processing speed, working memory, verbal fluency, and executive functioning) to assess ante mortem performance. We quantified the diameter of the lumen and arterial wall thickness obtained during autopsy. The diagnoses of HAND were attributed using the American Academy of Neurology nosology. We used generalized linear mixed model to account for repeated measures, follow-up time, and codependence between arteries. Models were adjusted for demographics, viral loads, CD4 counts, history of opportunistic infections, and vascular risks. Results: We included 94 HIV+ individuals (mean age 56 ± 8.3, 68% men, 54% African American). In adjusted models, there was an association between arterial wall thickness and global cognitive score (B = -0.176, P value = .03), processing speed (B = -0.175, P = .05), and verbal fluency (B = -0.253, P = .02). Participants with incident or worsening HAND had thicker brain arterial walls (B = 0.523 ± 0.234, P = .03) and smaller arterial lumen (B = -0.633 ± 0.252, P = .01). Conclusions: We report here a novel association between brain arterial wall thickening and poorer ante mortem cognitive performance and diagnosis of incident or worsening HAND at death. Strategies to preserve the arterial lumen or to prevent wall thickening may impact HAND.

Proteomic analysis of cerebrospinal fluid extracellular vesicles reveals synaptic injury, inflammation, and stress response markers in HIV patients with cognitive impairment.

BACKGROUND: Extracellular vesicles (EVs) are nano-sized particles present in most body fluids including cerebrospinal fluid (CSF). Little is known about CSF EV proteins in HIV+ individuals. Here, we characterize the CSF EV proteome in HIV+ subjects and its relationship to neuroinflammation, stress responses, and HIV-associated neurocognitive disorders (HAND). METHODS: CSF EVs isolated from 20 HIV+ subjects with (n = 10) or without (n = 10) cognitive impairment were characterized by electron microscopy, nanoparticle tracking analysis, immunoblotting, and untargeted LC/MS/MS mass spectrometry. Functional annotation was performed by gene ontology (GO) mapping and expression annotation using Biobase Transfac and PANTHER software. Cultured astrocytic U87 cells were treated with hydrogen peroxide for 4 h to induce oxidative stress and EVs isolated by ultracentrifugation. Selected markers of astrocytes (GFAP, GLUL), inflammation (CRP), and stress responses (PRDX2, PARK7, HSP70) were evaluated in EVs released by U87 cells following induction of oxidative stress and in CSF EVs from HIV+ patients by immunoblotting. RESULTS: Mass spectrometry identified 2727 and 1626 proteins in EV fractions and EV-depleted CSF samples, respectively. CSF EV fractions were enriched with exosomal markers including Alix, syntenin, tetraspanins, and heat-shock proteins and a subset of neuronal, astrocyte, oligodendrocyte, and choroid plexus markers, in comparison to EV-depleted CSF. Proteins related to synapses, immune/inflammatory responses, stress responses, metabolic processes, mitochondrial functions, and blood-brain barrier were also identified in CSF EV fractions by GO mapping. HAND subjects had higher abundance of CSF EVs and proteins mapping to GO terms for synapses, glial cells, inflammation, and stress responses compared to those without HAND. GFAP, GLUL, CRP, PRDX2, PARK7, and HSP70 were confirmed by immunoblotting of CSF EVs from subjects with HAND and were also detected in EVs released by U87 cells under oxidative stress. CONCLUSIONS: These findings suggest that CSF EVs derived from neurons, glial cells, and choroid plexus carry synaptic, immune/inflammation-related, and stress response proteins in HIV+ individuals with cognitive impairment, representing a valuable source for biomarker discovery.

Brain Large Artery Lymphocytic Inflammation and Human Immunodeficiency Virus-Related Brain Arterial Remodeling.

The pathogenesis of increased stroke risk in human immunodeficiency virus (HIV) remains unclear. Our study investigated the relationship between adventitial and intimal CD3+ T cells and brain arterial remodeling that potentially contributes to HIV-related vasculopathy and stroke. Large brain arteries from 84 HIV+ cases and 78 HIV- cases were analyzed to determine interadventitial and luminal diameters, intimal and wall thickness, percent stenosis, and the presence of atherosclerosis. Immunohistochemical analysis was performed to detect and visually score CD3, a pan-T-cell marker, in the intima and adventitia. Our study showed that numbers of adventitial CD3+ T cells are lower among persons with HIV than among those without HIV, especially if CD4 counts are <200, though intimal CD3+ T cell numbers did not differ by HIV status. Among those with HIV but CD4 counts of <200 at the time of death, intimal CD3+ T cells were associated with hypertrophic outward remodeling, while among those with HIV and CD4 of >200 or HIV- controls, intimal CD3+ T cells were associated with hypertrophic inward remodeling. We conclude that intimal lymphocytic inflammation is involved in brain arterial remodeling that may contribute to HIV-related cerebrovascular pathology.IMPORTANCE Although mortality from human immunodeficiency virus (HIV) has decreased with the use of combination antiretroviral therapies, there is now an increased risk of cardiovascular and cerebrovascular disease associated with HIV. Thus, there is a need to understand the pathogenesis of stroke in HIV infection. Our study examines how lymphocytic inflammation in brain arteries may contribute to increased cerebral vasculopathy. With this understanding, our study can potentially help direct future therapies to target and prevent brain arterial remodeling processes associated with HIV.

The effect of pyridostigmine on small intestinal bacterial overgrowth (SIBO) and plasma inflammatory biomarkers in HIV-associated autonomic neuropathies.

Small intestinal bacterial overgrowth (SIBO) is common among patients with HIV-associated autonomic neuropathies (HIV-AN) and may be associated with increased bacterial translocation and elevated plasma inflammatory biomarkers. Pyridostigmine is an acetylcholinesterase inhibitor which has been used to augment autonomic signaling. We sought preliminary evidence as to whether pyridostigmine could improve proximal gastrointestinal motility, reduce SIBO, reduce plasma sCD14 (a marker of macrophage activation and indirect measure of translocation), and reduce the inflammatory cytokines IL-6 and TNFα in patients with HIV-AN. Fifteen participants with well-controlled HIV, HIV-AN, and SIBO were treated with 8 weeks of pyridostigmine (30 mg PO TID). Glucose breath testing for SIBO, gastric emptying studies (GES) to assess motility, plasma sCD14, IL-6, and TNFα, and gastrointestinal autonomic symptoms were compared before and after treatment. Thirteen participants (87%) experienced an improvement in SIBO following pyridostigmine treatment; with an average improvement of 50% (p = 0.016). There was no change in gastrointestinal motility; however, only two participants met GES criteria for gastroparesis at baseline. TNFα and sCD14 levels declined by 12% (p = 0.004) and 19% (p = 0.015), respectively; there was no significant change in IL-6 or gastrointestinal symptoms. Pyridostigmine may ameliorate SIBO and reduce levels of sCD14 and TNFα in patients with HIV-AN. Larger placebo-controlled studies are needed to definitively delineate how HIV-AN affects gastrointestinal motility, SIBO, and systemic inflammation in HIV, and whether treatment improves clinical outcomes.