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.

Cannabis use may attenuate neurocognitive performance deficits resulting from methamphetamine use disorder.

OBJECTIVE: Methamphetamine and cannabis are two widely used, and frequently co-used, substances with possibly opposing effects on the central nervous system. Evidence of neurocognitive deficits related to use is robust for methamphetamine and mixed for cannabis. Findings regarding their combined use are inconclusive. We aimed to compare neurocognitive performance in people with lifetime cannabis or methamphetamine use disorder diagnoses, or both, relative to people without substance use disorders. METHOD: 423 (71.9% male, aged 44.6 ± 14.2 years) participants, stratified by presence or absence of lifetime methamphetamine (M-/M+) and/or cannabis (C-/C+) DSM-IV abuse/dependence, completed a comprehensive neuropsychological, substance use, and psychiatric assessment. Neurocognitive domain T-scores and impairment rates were examined using multiple linear and binomial regression, respectively, controlling for covariates that may impact cognition. RESULTS: Globally, M+C+ performed worse than M-C- but better than M+C-. M+C+ outperformed M+C- on measures of verbal fluency, information processing speed, learning, memory, and working memory. M-C+ did not display lower performance than M-C- globally or on any domain measures, and M-C+ even performed better than M-C- on measures of learning, memory, and working memory. CONCLUSIONS: Our findings are consistent with prior work showing that methamphetamine use confers risk for worse neurocognitive outcomes, and that cannabis use does not appear to exacerbate and may even reduce this risk. People with a history of cannabis use disorders performed similarly to our nonsubstance using comparison group and outperformed them in some domains. These findings warrant further investigation as to whether cannabis use may ameliorate methamphetamine neurotoxicity.

Distinct effects of SSRIs and SNRIs on Soluble Biomarkers in Blood and Cerebrospinal Fluid of people with HIV.

BACKGROUND: Persistent inflammation affects people with HIV (PWH) despite antiretroviral therapy (ART). Selective serotonin and serotonin-norepinephrine reuptake inhibitors (SSRIs, SNRIs), HMG-CoA reductase-inhibitors (statins), and angiotensin-converting enzyme inhibitors (ACEIs) have immuno-modulant properties. We evaluated the potential impact of these drugs on inflammation and neurodegeneration in PWH. METHODS: Cross-sectional single-center (U.S.) analysis in 184 PWH on ART with plasma HIV RNA < 200 cp/mL. All participants had 10 biomarkers measured in blood and cerebrospinal fluid (CSF). To reduce dimensionality, hierarchical clustering and principal components (PCs) analysis were employed. The analyses were adjusted for duration of the drugs and and clinical conditions. RESULTS: Participants were mostly middle-aged men, with median CD4+ T-cells of 620/µL. In adjusted models, SSRI use was associated with three PCs: higher CSF and plasma Aß42 and CSF CCL2 (aß=0.14, p = 0.040); lower CSF 8-oxo-dG, total tau, and sCD14 (aß=-0.12, p = 0.042); higher plasma sCD14 with lower sCD40L (aß=0.15, p = 0.042). SNRI use was associated with higher values of CSF and plasma neopterin and CSF sTNFR-II (aß=0.22, p = 0.004). Statins and ACEIs showed no association. CONCLUSIONS: SSRIs and SNRIs had distinct biomarker signatures. SSRIs were associated with reduced neurodegeneration, immune activation and oxidative stress in CSF, suggesting a role of SSRIs as adjunctive therapy in PWH.

Increasing Neuroinflammation Relates to Increasing Neurodegeneration in People with HIV.

BACKGROUND: HIV infection causes neuroinflammation and immune activation (NIIA) and systemic inflammation and immune activation (SIIA), which in turn drive neurodegeneration (ND). Cross-sectionally, higher levels of NIIA biomarkers correlate with increased biomarkers of ND. A more convincing confirmation would be a longitudinal demonstration. METHODS: PWH in the US multisite CHARTER Aging project were assessed at a baseline visit and after 12 years using standardized evaluations. We measured a panel of 14 biomarkers of NIIA, SIIA, and ND in plasma and CSF at two time points and calculated changes from baseline to the 12-year visit. Factor analysis yielded simplified indices of NIIA, SIIA, and ND. RESULTS: The CSF NIIA factor analysis yielded Factor1 loading on soluble tumor necrosis factor type-2 (sTNFR-II) and neopterin, and Factor2, loading on MCP1, soluble CD14, and IL-6. The SIIA factor analysis yielded Factor1 loading on CRP, D-dimer, and Neopterin; Factor2 loading on sTNFR-II. The ND analysis yielded Factor1 loading on Phosphorylated tau (p-tau) and Aß42; Factor2 loading on NFL. NIIA Factor1, but not Factor2, correlated with increases in CSF NFL (r = 0.370, p = 0.0002). CONCLUSIONS: Increases in NIIA and SIIA in PWH were associated with corresponding increases in ND, suggesting that reducing neuro/systemic inflammation might slow or reverse neurodegeneration.

Reply to Augello, P.A.; Wu, J. Comment on "Rogers et al. The Combined Effects of Cannabis, Methamphetamine, and HIV on Neurocognition. Viruses 2023, 15, 674".

We thank Augello and Wu [...].

Combined effects of loneliness and inflammation on depression in people with HIV.

OBJECTIVE: Loneliness is prevalent in people with HIV (PWH) and associated with adverse health-related consequences, including depression. Chronic inflammation has been linked to depression in PWH, though its association with loneliness is less well established. Simultaneous examination of inflammation, loneliness and depression is needed to clarify these relationships. This study investigated the relationship between loneliness and inflammation, and the effects of loneliness and inflammation on depression in PWH. METHODS: 82 PWH who were on suppressive ART (mean age [SD] = 53.2 [9.0]) completed the UCLA Loneliness Scale-Version 3 and the Center for Epidemiologic Studies Depression Scale as part of a comprehensive evaluation. Biomarkers of systemic inflammation (CRP, IL-6, CCL2/MCP-1, sCD14) and coagulation (D-dimer) were measured in blood using commercial immunoassays. RESULTS: Multivariable linear regression analyses revealed that higher D-dimer, CCL2/MCP-1, and sCD14 were significant predictors of loneliness (ps < .05) while accounting for relevant covariates. Stepwise multiple linear regression models that included loneliness, biomarkers, and their interactions as predictors of depressive symptoms revealed significant main effects of loneliness and CCL2/MCP-1 levels (ps < .05), and a significant loneliness by D-dimer interaction (p < .05) whereby higher D-dimer was associated with increased depressive symptoms only at higher levels of loneliness. CONCLUSIONS: Increased coagulation activity is associated with loneliness, and in the context of loneliness, may increase risk for depression. Increased inflammation was associated with depression suggesting potentially dissociable underlying biological processes. To the extent that these processes are modifiable, such findings could have important implications in the treatment of loneliness and depression in PWH.

MRP8/14 Is a Molecular Signature Triggered by Dopamine in HIV Latent Myeloid Targets That Increases HIV Transcription and Distinguishes HIV+ Methamphetamine Users with Detectable CSF Viral Load and Brain Pathology.

There is a significant overlap between HIV infection and substance-use disorders. Dopamine (DA) is the most abundantly upregulated neurotransmitter in methamphetamine abuse, with receptors (DRD1-5) that are expressed by neurons as well as by a large diversity of cell types, including innate immune cells that are the targets of HIV infection, making them responsive to the hyperdopaminergic environment that is characteristic of stimulant drugs. Therefore, the presence of high levels of dopamine may affect the pathogenesis of HIV, particularly in the brain. The stimulation of HIV latently infected U1 promonocytes with DA significantly increased viral p24 levels in the supernatant at 24 h, suggesting effects on activation and replication. Using selective agonists to different DRDs, we found that DRD1 played a major role in activating viral transcription, followed by DRD4, which increased p24 with a slower kinetic rate compared to DRD1. Transcriptome and systems biology analyses led to the identification of a cluster of genes responsive to DA, where S100A8 and S100A9 were most significantly correlated with the early increase in p24 levels following DA stimulation. Conversely, DA increased the expression of these genes' transcripts at the protein level, MRP8 and MRP14, respectively, which form a complex also known as calprotectin. Interestingly, MRP8/14 was able to stimulate HIV transcription in latent U1 cells, and this occurred via binding of the complex to the receptor for an advanced glycosylation end-product (RAGE). Using selective agonists, both DRD1 and DRD4 increased MRP8/14 on the surface, in the cytoplasm, as well as secreted in the supernatants. On the other hand, while DRD1/5 did not affect the expression of RAGE, DRD4 stimulation caused its downregulation, offering a mechanism for the delayed effect via DRD4 on the p24 increase. To cross-validate MRP8/14 as a DA signature with a biomarker value, we tested its expression in HIV+ Meth users' postmortem brain specimens and peripheral cells. MRP8/14+ cells were more frequently identified in mesolimbic areas such as the basal ganglia of HIV+ Meth+ cases compared to HIV+ non-Meth users or to controls. Likewise, MRP8/14+ CD11b+ monocytes were more frequent in HIV+ Meth users, particularly in specimens from participants with a detectable viral load in the CSF. Overall, our results suggest that the MRP8 and MRP14 complex may serve as a signature to distinguish subjects using addictive substances in the context of HIV, and that this may play a role in aggravating HIV pathology by promoting viral replication in people with HIV who use Meth.

Signatures of HIV and Major Depressive Disorder in the Plasma Microbiome.

Inter-individual differences in the gut microbiome are linked to alterations in inflammation and blood-brain barrier permeability, which may increase the risk of depression in people with HIV (PWH). The microbiome profile of blood, which is considered by many to be typically sterile, remains largely unexplored. We aimed to characterize the blood plasma microbiome composition and assess its association with major depressive disorder (MDD) in PWH and people without HIV (PWoH). In this cross-sectional, observational cohort, we used shallow-shotgun metagenomic sequencing to characterize the plasma microbiome of 151 participants (84 PWH and 67 PWoH), all of whom underwent a comprehensive neuropsychiatric assessment. The microbial composition did not differ between PWH and PWoH or between participants with MDD and those without it. Using the songbird model, we computed the log ratio of the highest and lowest 30% of the ranked classes associated with HIV and MDD. We found that HIV infection and lifetime MDD were enriched in a set of differentially abundant inflammatory classes, such as Flavobacteria and Nitrospira. Our results suggest that the circulating plasma microbiome may increase the risk of MDD related to dysbiosis-induced inflammation in PWH. If confirmed, these findings may indicate new biological mechanisms that could be targeted to improve treatment of MDD in PWH.

The Combined Effects of Cannabis, Methamphetamine, and HIV on Neurocognition.

OBJECTIVE: Methamphetamine and cannabis are two widely used substances among people living with HIV (PLWH). Whereas methamphetamine use has been found to worsen HIV-associated neurocognitive impairment, the effects of combined cannabis and methamphetamine use disorder on neurocognition in PLWH are not understood. In the present study, we aimed to determine the influence of these substance use disorders on neurocognition in PLWH and to explore if methamphetamine-cannabis effects interacted with HIV status. METHOD AND PARTICIPANTS: After completing a comprehensive neurobehavioral assessment, PLWH (n = 472) were stratified by lifetime methamphetamine (M-/M+) and cannabis (C-/C+) DSM-IV abuse/dependence disorder into four groups: M-C- (n = 187), M-C+ (n = 68), M+C-, (n = 82), and M+C+ (n = 135). Group differences in global and domain neurocognitive performances and impairment were examined using multiple linear and logistic regression, respectively, while holding constant other covariates that were associated with study groups and/or cognition. Data from participants without HIV (n = 423) were added, and mixed-effect models were used to examine possible interactions between HIV and substance use disorders on neurocognition. RESULTS: Compared with M+C+, M+C- performed worse on measures of executive functions, learning, memory, and working memory and were more likely to be classified as impaired in those domains. M-C- performed better than M+C+ on measures of learning and memory but worse than M-C+ on measures of executive functions, learning, memory, and working memory. Detectable plasma HIV RNA and nadir CD4 < 200 were associated with lower overall neurocognitive performance, and these effects were greater for M+C+ compared with M-C-. CONCLUSIONS: In PLWH, lifetime methamphetamine use disorder and both current and legacy markers of HIV disease severity are associated with worse neurocognitive outcomes. There was no evidence of an HIV × M+ interaction across groups, but neurocognition was most impacted by HIV among those with polysubstance use disorder (M+C+). Better performance by C+ groups is consistent with findings from preclinical studies that cannabis use may protect against methamphetamine's deleterious effects.

Concurrent validity and reliability of at-home teleneuropsychological evaluations among people with and without HIV.

OBJECTIVE: To determine the reliability of teleneuropsychological (TNP) compared to in-person assessments (IPA) in people with HIV (PWH) and without HIV (HIV-). METHODS: Participants included 80 PWH (Mage = 58.7, SDage = 11.0) and 23 HIV- (Mage = 61.9, SDage = 16.7). Participants completed two comprehensive neuropsychological IPA before one TNP during the COVID-19 pandemic (March-December 2020). The neuropsychological tests included: Hopkins Verbal Learning Test-Revised (HVLT-R Total and Delayed Recall), Controlled Oral Word Association Test (COWAT; FAS-English or PMR-Spanish), Animal Fluency, Action (Verb) Fluency, Wechsler Adult Intelligence Scale 3rd Edition (WAIS-III) Symbol Search and Letter Number Sequencing, Stroop Color and Word Test, Paced Auditory Serial Addition Test (Channel 1), and Boston Naming Test. Total raw scores and sub-scores were used in analyses. In the total sample and by HIV status, test-retest reliability and performance-level differences were evaluated between the two consecutive IPA (i.e., IPA1 and IPA2), and mean in-person scores (IPA-M), and TNP. RESULTS: There were statistically significant test-retest correlations between IPA1 and IPA2 (r or ρ = .603-.883, ps < .001), and between IPA-M and TNP (r or ρ = .622-.958, ps < .001). In the total sample, significantly lower test-retest scores were found between IPA-M and TNP on the COWAT (PMR), Stroop Color and Word Test, WAIS-III Letter Number Sequencing, and HVLT-R Total Recall (ps < .05). Results were similar in PWH only. CONCLUSIONS: This study demonstrates reliability of TNP in PWH and HIV-. TNP assessments are a promising way to improve access to traditional neuropsychological services and maintain ongoing clinical research studies during the COVID-19 pandemic.

Plasma biomarkers of vascular dysfunction uniquely relate to a vascular-risk profile of neurocognitive deficits in virally-suppressed adults with HIV.

Objective: Chronic inflammation and vascular dysfunction (e.g., chronic endothelial activation) are related yet dissociable mechanisms of HIV-associated neurocognitive impairment (NCI), even among those on antiretroviral therapy (ART). However, how these mechanisms differentially contribute to domain-specific deficits in people with and without HIV (PWH, PWoH) is unclear. We empirically-derived profiles of NCI and examined relationships with peripheral inflammatory and vascular biomarkers. Methods: Participants were 84 virally-suppressed PWH and 126 PWoH who underwent neuropsychological testing and blood draw. Cluster analysis identified subgroups based on domain deficit scores. ANOVAs examined HIV serostatus and cluster group differences in composite plasma biomarker z-scores of inflammation (IL-6, CXCL10/IP-10, CCL2/MCP-1) and vascular injury (VCAM-1, ICAM-1, uPAR). Confirmatory regressions examined the interaction of HIV and biomarker z-scores on domain-specific T-scores, controlling for cardiovascular disease (CVD) risk and psychosocial factors. Results: Cluster analysis identified three groups: Unimpaired (n = 129), Learning/Recall (n = 52, isolated learning/recall deficits), Dysexecutive/Slow (n = 29, executive function, working memory, processing speed, and motor deficits). PWH had higher odds of Dysexecutive/Slow membership, which related to CVD risk and higher vascular dysfunction, but not inflammation, in PWH. Vascular biomarkers moderated adverse HIV effects on executive function, processing speed, and working memory such that PWH had lower T-scores only when vascular dysfunction was high. Conclusions: In PWH with controlled disease, peripheral markers of endothelial dysfunction and vascular permeability are selectively associated with an empirically-derived subgroup that exhibits domain deficits commonly impacted by cerebrovascular disease. Findings support the presence of a vascular NCI subgroup of PWH who may benefit from interventions that directly target the neurovascular unit.

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.

Relationship of the balloon analog risk task to neurocognitive impairment differs by HIV serostatus and history of major depressive disorder.

HIV and major depressive disorder (MDD) commonly co-occur and are both linked to greater risk-taking behavior, possibly due to neurocognitive impairment (NCI). The present study examined the concordance of the Balloon Analog Risk Task (BART), a gold standard measure of risk-taking propensity, with NCI and real-world sexual risk behaviors in PWH with comorbid MDD. Participants included 259 adults, stratified by HIV serostatus (HIV + /HIV -) and lifetime MDD (MDD + /MDD -), who completed neuropsychological testing, the BART, and sexual risk behavior questionnaires. Logistic regression, stratified by HIV serostatus, examined joint effects of MDD and BART (linear and quadratic) on NCI. Follow-up linear regressions examined sexual risk behavior and neurocognitive domain T-scores as correlates of the BART. NCI prevalence was lowest in HIV - /MDD - , but BART scores did not differ by HIV/MDD status. In the HIV + group, BART performance predicted NCI such that high and low BART scores related to greater odds of NCI, but only in dual-risk HIV + /MDD + individuals. HIV + /MDD + individuals with both low and high BART scores exhibited poorer learning and recall, whereas processing speed and executive function were only poor in low BART risk-taking HIV + /MDD + . Higher BART scores linearly related to higher sexual risk behaviors only in MDD + individuals, independent of HIV serostatus. Low and high risk-taking on the BART may reflect discrete neurocognitive profiles in HIV + /MDD + individuals, with differential implications for real-world sexual risk behavior. HIV and comorbid MDD may disturb corticostriatal circuits responsible for integrating affective and neurocognitive components of decision-making, thereby contributing to risk-averse and risk-taking phenotypes.

Loneliness, Risky Beliefs and Intentions about Practicing Safer Sex among Methamphetamine Dependent Individuals.

BACKGROUND: Methamphetamine use is a known predictor of riskier sexual behaviors, which can have important public health implications (e.g., HIV-transmission risk). Loneliness also is associated with riskier sexual behaviors, though the relationship between loneliness and beliefs and/or intentions to practice safer sex has not been examined among people dependent on methamphetamine. MATERIALS AND METHODS: Individuals who met DSM-IV criteria for lifetime methamphetamine dependence and current (≤ 18-months) methamphetamine abuse or dependence (METH+ n = 56) were compared to those without severity and recency of methamphetamine use (METH- n = 59). These groups did not differ on social network size or proportion of people with HIV (∼58% HIV+). Participants completed the NIH Toolbox Loneliness Scale and the Sexual Risks Scale's "Norms" and "Intentions" subscales. RESULTS: METH+ individuals were significantly lonelier than METH- controls (t(113) = 2.45, p = .02). Methamphetamine dependence remained significantly associated with greater loneliness, after controlling for HIV status and other relevant covariates (e.g., neurocognitive impairment, history of mood disorder, social network size; F = 3.70, Adjusted R2 = 0.18, p = .0009). Loneliness, above and beyond the aforementioned covariates, was significantly associated with riskier beliefs and intentions to practice safer sex among METH+, but not METH-, individuals (ß = 2.92, p = .02). CONCLUSIONS: Loneliness is prevalent among individuals dependent on methamphetamine, and is uniquely associated with riskier beliefs and intentions regarding practicing safer sex. Findings may aid in identifying individuals at-risk of engaging in riskier sexual behaviors and guide risk prevention strategies.

Markers of Gut Barrier Function and Microbial Translocation Associate with Lower Gut Microbial Diversity in People with HIV.

People with human immunodeficiency virus (HIV) (PWH) have reduced gut barrier integrity ("leaky gut") that permits diffusion of microbial antigens (microbial translocation) such as lipopolysaccharide (LPS) into the circulation, stimulating inflammation. A potential source of this disturbance, in addition to gut lymphoid tissue CD4+ T-cell depletion, is the interaction between the gut barrier and gut microbes themselves. We evaluated the relationship of gut barrier integrity, as indexed by plasma occludin levels (higher levels corresponding to greater loss of occludin from the gut barrier), to gut microbial diversity. PWH and people without HIV (PWoH) participants were recruited from community sources and provided stool, and 16S rRNA amplicon sequencing was used to characterize the gut microbiome. Microbial diversity was indexed by Faith's phylogenetic diversity (PD). Participants were 50 PWH and 52 PWoH individuals, mean ± SD age 45.6 ± 14.5 years, 28 (27.5%) women, 50 (49.0%) non-white race/ethnicity. PWH had higher gut microbial diversity (Faith's PD 14.2 ± 4.06 versus 11.7 ± 3.27; p = 0.0007), but occludin levels were not different (1.84 ± 0.311 versus 1.85 ± 0.274; p = 0.843). Lower gut microbial diversity was associated with higher plasma occludin levels in PWH (r = -0.251; p = 0.0111), but not in PWoH. A multivariable model demonstrated an interaction (p = 0.0459) such that the correlation between Faith's PD and plasma occludin held only for PWH (r = -0.434; p = 0.0017), but not for PWoH individuals (r = -0.0227; p = 0.873). The pattern was similar for Shannon alpha diversity. Antiretroviral treatment and viral suppression status were not associated with gut microbial diversity (ps > 0.10). Plasma occludin levels were not significantly related to age, sex or ethnicity, nor to current or nadir CD4 or plasma viral load. Higher occludin levels were associated with higher plasma sCD14 and LPS, both markers of microbial translocation. Together, the findings suggest that damage to the gut epithelial barrier is an important mediator of microbial translocation and inflammation in PWH, and that reduced gut microbiome diversity may have an important role.

Alterations in Brain Cannabinoid Receptor Levels Are Associated with HIV-Associated Neurocognitive Disorders in the ART Era: Implications for Therapeutic Strategies Targeting the Endocannabinoid System.

HIV-associated neurocognitive disorders (HAND) persist despite the advent of antiretroviral therapy (ART), suggesting underlying systemic and central nervous system (CNS) inflammatory mechanisms. The endogenous cannabinoid receptors 1 and 2 (CB1 and CB2) modulate inflammatory gene expression and play an important role in maintaining neuronal homeostasis. Cannabis use is disproportionately high among people with HIV (PWH) and may provide a neuroprotective effect for those on ART due to its anti-inflammatory properties. However, expression profiles of CB1 and CB2 in the brains of PWH on ART with HAND have not been reported. In this study, biochemical and immunohistochemical analyses were performed to determine CB1 and CB2 expression in the brain specimens of HAND donors. Immunoblot revealed that CB1 and CB2 were differentially expressed in the frontal cortices of HAND brains compared to neurocognitively unimpaired (NUI) brains of PWH. CB1 expression levels negatively correlated with memory and information processing speed. CB1 was primarily localized to neuronal soma in HAND brains versus a more punctate distribution of neuronal processes in NUI brains. CB1 expression was increased in cells with glial morphology and showed increased colocalization with an astroglial marker. These results suggest that targeting the endocannabinoid system may be a potential therapeutic strategy for HAND.

Daily Cannabis Use is Associated With Lower CNS Inflammation in People With HIV.

OBJECTIVE: Recent cannabis exposure has been associated with lower rates of neurocognitive impairment in people with HIV (PWH). Cannabis's anti-inflammatory properties may underlie this relationship by reducing chronic neuroinflammation in PWH. This study examined relations between cannabis use and inflammatory biomarkers in cerebrospinal fluid (CSF) and plasma, and cognitive correlates of these biomarkers within a community-based sample of PWH. METHODS: 263 individuals were categorized into four groups: HIV- non-cannabis users (n = 65), HIV+ non-cannabis users (n = 105), HIV+ moderate cannabis users (n = 62), and HIV+ daily cannabis users (n = 31). Differences in pro-inflammatory biomarkers (IL-6, MCP-1/CCL2, IP-10/CXCL10, sCD14, sTNFR-II, TNF-α) by study group were determined by Kruskal-Wallis tests. Multivariable linear regressions examined relationships between biomarkers and seven cognitive domains, adjusting for age, sex/gender, race, education, and current CD4 count. RESULTS: HIV+ daily cannabis users showed lower MCP-1 and IP-10 levels in CSF compared to HIV+ non-cannabis users (p = .015; p = .039) and were similar to HIV- non-cannabis users. Plasma biomarkers showed no differences by cannabis use. Among PWH, lower CSF MCP-1 and lower CSF IP-10 were associated with better learning performance (all ps < .05). CONCLUSIONS: Current daily cannabis use was associated with lower levels of pro-inflammatory chemokines implicated in HIV pathogenesis and these chemokines were linked to the cognitive domain of learning which is commonly impaired in PWH. Cannabinoid-related reductions of MCP-1 and IP-10, if confirmed, suggest a role for medicinal cannabis in the mitigation of persistent inflammation and cognitive impacts of HIV.

Telomere length is associated with HIV infection, methamphetamine use, inflammation, and comorbid disease risk.

BACKGROUND: HIV infection and methamphetamine dependence (METH) are each associated with inflammation and premature aging, but their impact on biological aging is difficult to measure. Here we examined the impact of HIV and METH on leukocyte telomere lengths (LTL), and the correlations between LTL and other aging biomarkers. METHODS: The study was a cross-sectional analysis of 161 individuals categorized by HIV and methamphetamine (METH) dependence status into four groups: HIV-METH- (n = 50), HIV-METH+ (n = 29), HIV + METH- (n = 40), and HIV + METH+ (n = 42). We analyzed the relationships of leukocyte telomere length (telomere to single copy gene [T/S] ratio) with demographic and clinical data as well as a panel of biomarkers of inflammation and endothelial activation measured in blood and cerebrospinal fluid (CSF). RESULTS: HIV and METH were independently associated with shorter T/S ratio, even after adjusting for demographics and leukocyte count (R2 = 0·59, p < 0·0001). Higher plasma C-reactive protein (p = 0·0036) and CSF VCAM-1 (p = 0·0080) were also associated with shorter T/S ratio. A shorter T/S ratio was associated with higher risk for cardiovascular disease (p < 0·0001) and stroke (p < 0·0001), worse motor functioning (p = 0·037) and processing speed (p = 0·023), more depressive symptoms (p = 0·013), and higher CSF neurofilament-light (p = 0·003). CONCLUSIONS: HIV and METH dependence were each associated with shorter telomeres. After adjusting for demographics, HIV, and METH, T/S ratio remained associated with aging-related outcomes including neurocognitive impairment, neurodegeneration, risks of cardiovascular disease and stroke. While not establishing causality, this study supports using the T/S ratio as a biomarker for estimating the impact of HIV and comorbidities on long-term health.

Apathy is associated with poorer abstinence self-efficacy in individuals with methamphetamine dependence.

BACKGROUND: Confidence in one's ability to achieve and maintain drug abstinence (i.e., abstinence self-efficacy) is a strong predictor of substance use treatment outcomes. Neurobehavioral factors that may interfere with abstinence self-efficacy are less well established, particularly in methamphetamine (METH). This study investigated whether apathy, which is highly prevalent during active METH use and periods of abstinence, influences abstinence self-efficacy among METH dependent individuals. METHODS: Sixty-six participants with lifetime METH dependence and METH abuse/METH dependence diagnoses within the last 18 months (mean age [SD] = 39.5 years [10.7]), and no severe psychiatric or neurological diseases, completed the Methamphetamine Self-Efficacy Scale (MSES), alongside a comprehensive neurobehavioral evaluation. The MSES presents six situations that may lead to relapse and collects self-report ratings for two subscales: "Confidence" (i.e., confidence in one's ability to abstain from using METH, or METH abstinence self-efficacy) and "Temptation" (i.e., how tempted one is to use METH) with regard to each situation. Apathy was measured using a composite T-score comprised of items and scales from three well-validated, self-report assessments. RESULTS: Multivariable linear regression found that higher Apathy T-scores were significantly associated with lower Confidence ratings (i.e., poorer METH abstinence self-efficacy; p < .05), independent of potentially relevant factors (e.g., Temptation to use METH, comorbid HIV disease, and neurocognitive impairment). CONCLUSIONS: Elevated apathy may adversely impact one's confidence to abstain from METH use. Findings highlight the importance of addressing apathy in order to improve METH abstinence self-efficacy, which may subsequently increase the likelihood of successful METH treatment outcomes.

Chronically elevated depressive symptoms interact with acute increases in inflammation to predict worse neurocognition among people with HIV.

We examined the joint effects of depressive symptoms (Beck Depression Inventory-II (BDI-II)) and systemic inflammation (plasma C-reactive protein (CRP)) on longitudinal profiles of neurocognition in a cohort of 143 people with HIV (PWH) on antiretroviral therapy. Global neurocognition, processing speed, motor skills, and attention/working memory all worsened as CRP increased but only among PWH who, on average, exhibited moderate to severe depressive symptoms (BDI-II > 22). Findings suggest that some PWH with chronically elevated depressive symptoms may have an inflammatory subtype of depression and a particular vulnerability to neurocognitive changes that may respond to drugs targeting inflammation or its neural sequelae.