Genetic Variations in EIF2AK3 are Associated with Neurocognitive Impairment in People Living with HIV

Based on emerging evidence on the role for specific single-nucleotide variants (SNVs) in EIF2AK3 encoding the integrated stress response kinase PERK, in neurodegeneration, we assessed the association of EIF2AK3 SNVs with neurocognitive performance in people with HIV (PWH) using a candidate gene approach. This retrospective study included the CHARTER cohort participants, excluding those with severe neuropsychiatric comorbidities. Genome-wide data previously obtained for 1047 participants and targeted sequencing of 992 participants with available genomic DNA were utilized to interrogate the association of three noncoding and three coding EIF2AK3 SNVs with the continuous global deficit score (GDS) and global neurocognitive impairment (NCI; GDS ≥ 0.5) using univariable and multivariable methods, with demographic, disease-associated, and treatment characteristics as covariates. The cohort characteristics were as follows: median age, 43.1 years; females, 22.8%; European ancestry, 41%; median CD4 + T cell counts, 175/µL (nadir) and 428/µL (current). At first assessment, 70.5% used ART and 68.3% of these had plasma HIV RNA levels ≤ 200 copies/mL. All three noncoding EIF2AK3 SNVs were associated with GDS and NCI (all p < 0.05). Additionally, 30.9%, 30.9%, and 41.2% of participants had at least one risk allele for the coding SNVs rs1805165 (G), rs867529 (G), and rs13045 (A), respectively. Homozygosity for all three coding SNVs was associated with significantly worse GDS (p < 0.001) and more NCI (p < 0.001). By multivariable analysis, the rs13045 A risk allele, current ART use, and Beck Depression Inventory-II value > 13 were independently associated with GDS and NCI (p < 0.001) whereas the other two coding SNVs did not significantly correlate with GDS or NCI after including rs13045 in the model. The coding EIF2AK3 SNVs were associated with worse performance in executive functioning, motor functioning, learning, and verbal fluency. Coding and non-coding SNVs of EIF2AK3 were associated with global NC and domain-specific performance. The effects were small-to-medium in size but present in multivariable analyses, raising the possibility of specific SNVs in EIF2AK3 as an important component of genetic vulnerability to neurocognitive complications in PWH.

Distinct Effects of Selective Serotonin Reuptake Inhibitors and Serotonin-Norepinephrine Reuptake Inhibitors 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 immunomodulant properties. We evaluated the potential impact of these drugs on inflammation and neurodegeneration in PWH.

METHODS

Cross-sectional single-center (United States) analysis in 184 PWH on ART with plasma HIV RNA < 200 copies/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 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 3 PCs: higher CSF and plasma Aβ42 and CSF CCL2 (aβ=.14, P = .040); lower CSF 8-oxo-dG, total tau, and sCD14 (aβ=-.12, P = .042); and higher plasma sCD14 with lower sCD40L (aβ=.15, P = .042). SNRI use was associated with higher values of CSF and plasma neopterin and CSF sTNFR-II (aβ=.22, P = .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.

Elevated Biomarkers of Inflammation and Vascular Dysfunction Are Associated with Distal Sensory Polyneuropathy in People with HIV

Distal sensory polyneuropathy (DSP) is a disabling, chronic condition in people with HIV (PWH), even those with viral suppression of antiretroviral therapy (ART), and with a wide range of complications, such as reduced quality of life. Previous studies demonstrated that DSP is associated with inflammatory cytokines in PWH. Adhesion molecules, essential for normal vascular function, are perturbed in HIV and other conditions linked to DSP, but the link between adhesion molecules and DSP in PWH is unknown. This study aimed to determine whether DSP signs and symptoms were associated with a panel of plasma biomarkers of inflammation (d-dimer, sTNFRII, MCP-1, IL-6, IL-8, IP-10, sCD14) and vascular I integrity (ICAM-1, VCAM-1, uPAR, MMP-2, VEGF, uPAR, TIMP-1, TIMP-2) and differed between PWH and people without HIV (PWoH). A cross-sectional study was conducted among 143 participants (69 PWH and 74 PWoH) assessed by studies at the UC San Diego HIV Neurobehavioral Research Program. DSP signs and symptoms were clinically assessed for all participants. DSP was defined as two or more DSP signs: bilateral symmetrically reduced distal vibration, sharp sensation, and ankle reflexes. Participant-reported symptoms were neuropathic pain, paresthesias, and loss of sensation. Factor analyses reduced the dimensionality of the 15 biomarkers among all participants, yielding six factors. Logistic regression was used to assess the associations between biomarkers and DSP signs and symptoms, controlling for relevant demographic and clinical covariates. The 143 participants were 48.3% PWH, 47 (32.9%) women, and 47 (33.6%) Hispanics, with a mean age of 44.3 ± 12.9 years. Among PWH, the median (IQR) nadir and current CD4+ T-cells were 300 (178-448) and 643 (502-839), respectively. Participants with DSP were older but had similar distributions of gender and ethnicity to those without DSP. Multiple logistic regression showed that Factor 2 (sTNFRII and VCAM-1) and Factor 4 (MMP-2) were independently associated with DSP signs in both PWH and PWoH (OR [95% CI]: 5.45 [1.42-21.00], and 15.16 [1.07-215.22]), respectively. These findings suggest that inflammation and vascular integrity alterations may contribute to DSP pathogenesis in PWH, but not PWoH, possibly through endothelial dysfunction and axonal degeneration.

The clinical utility of three frailty measures in identifying HIV-associated neurocognitive disorders

OBJECTIVE

Frailty measures vary widely and the optimal measure for predicting HIV-associated neurocognitive disorders (HAND) is unclear.

DESIGN

A study was conducted to examine the clinical utility of three widely used frailty measures in identifying HIV-associated neurocognitive disorders.

METHODS

The study involved 284 people with HIV (PWH) at least 50 years enrolled at UC San Diego's HIV Neurobehavioral Research Program. Frailty measurements included the Fried Phenotype, the Rockwood Frailty Index, and the Veterans Aging Cohort Study (VACS) Index. HAND was diagnosed according to Frascati criteria. ANOVAs examined differences in frailty severity across HAND conditions. ROC analyses evaluated sensitivity and specificity of each measure to detect symptomatic HAND [mild neurocognitive disorder (MND) and HIV-associated dementia (HAD)] from no HAND.

RESULTS

Across all frailty measures, frailty was found to be higher in HAD compared with no HAND. For Fried and Rockwood (not VACS), frailty was significantly more severe in MND vs. no HAND and in HAD vs. ANI (asymptomatic neurocognitive impairment). For discriminating symptomatic HAND from no HAND, Fried was 37% sensitive and 92% specific, Rockwood was 85% sensitive and 43% specific, and VACS was 58% sensitive and 65% specific.

CONCLUSION

These findings demonstrate that Fried and Rockwood outperform VACS in predicting HAND. However, ROC analyses suggest none of the indices had adequate predictive validity in detecting HAND. The results indicate that the combined use of the Rockwood and Fried indices may be an appropriate alternative.

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.

Identifying and distinguishing cognitive profiles among virally suppressed people with HIV

OBJECTIVE

Cognitive deficits are common among people with HIV (PWH), even when virally suppressed. We identified cognitive profiles among virally suppressed PWH and determined how sociodemographic, clinical/behavioral, and HIV disease characteristics distinguish profile membership.

METHOD

Participants included 704 virally suppressed PWH (Mage = 43.9 [SD = 10.2], 88% male, 58.9% non-Hispanic White) from the HIV Neurobehavioral Research Program. Demographically adjusted T scores were derived from a neuropsychological evaluation comprised of 13 tests. We implemented a pipeline involving dimension reduction and clustering to identify profiles of cognitive performance. Random forest models on a 70/30 training/testing set with internal cross-validation were used to identify sociodemographic, clinical/behavioral, and HIV disease correlates of profile membership.

RESULTS

Six cognitive profiles were identified: (a) "unimpaired" (19.9%); (b) weakness in verbal learning and memory (15.5%); (c) weakness in executive function and learning (25.8%); (d) weakness in motor, processing speed, and executive function (8.1%); (e) impaired learning and recall with weak-to-impaired motor, processing speed, and executive function (13.1%); (f) global deficits (17.6%). The most discriminative sociodemographic, clinical/behavioral, and HIV disease characteristics varied by profile with self-reported mood symptoms and cognitive/functional difficulties (e.g., language/communication, memory, and overall everyday function complaints) most consistently associated with profile membership.

CONCLUSIONS

Cognitive profiles and their associated factors among PWH are heterogeneous, but learning/memory deficits were most common and self-reported mood, and cognitive/functional difficulties were most consistently related to profile membership. This heterogeneity in cognitive profiles and their correlates in PWH suggests that differing mechanisms contribute to cognitive deficits and, thus, underscores the need for personalized risk reduction and therapeutic strategies among PWH. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Effects of Opioid Withdrawal on Psychobiology in People Living with HIV

OBJECTIVE

Many persons with opioid use disorders (OUDs) have HIV disease and experience clinically significant stress after they enroll in abstinence-based treatment and undergo medically assisted withdrawal. We examined whether opioid withdrawal affects virologic control, inflammatory markers, cognition, and mood in persons with an OUD and HIV, and explored whether measures of withdrawal stress, such as activation of the HPA axis, contribute to alterations in immune function, cognition, and mood.

METHOD AND PARTICIPANTS

Study participants were 53 persons with HIV who were admitted for OUD treatment at the City Addiction Hospital in Saint Petersburg, Russian Federation. Participants were examined at admission, at the anticipated peak of withdrawal 3 to 7 days after the last day of a clonidine-based withdrawal process lasting 7 to 14 days, and 3 to 4 weeks after completing withdrawal. At these times, participants received medical exams and were evaluated for symptoms of withdrawal, as well as cognition and mood. Viral load, plasma cortisol, DHEA sulfate ester (DHEA-S), interleukin-6 (IL-6), and soluble CD14 (sCD14) were determined. Multivariable models examined the relationships between markers of HPA activation and the other parameters over time.

RESULTS

HPA activation as indexed by cortisol/DHEA-S ratio increased during withdrawal, as did markers of immune activation, IL-6 and sCD14. There were no significant associations between viral load and indicators of HPA activation. In longitudinal analyses, higher cortisol/DHEA sulfate was related to worse cognition overall, and more mood disturbance. Increase in IL-6 was associated with worse cognitive performance on a learning task. There were no significant associations with sCD14.

CONCLUSIONS

Worsening of cognition and measures of mood disturbance during withdrawal were associated with activation of the HPA axis and some measures of inflammation. Whether repeated episodes of opioid withdrawal have a cumulative impact on long-term HIV outcomes and neurocognition is a topic for further investigation.

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.

Elevated Plasma Protein Carbonyl Concentration Is Associated with More Abnormal White Matter in People with HIV

Structural brain abnormalities, including those in white matter (WM), remain common in people with HIV (PWH). Their pathogenesis is uncertain and may reflect multiple etiologies. Oxidative stress is associated with inflammation, HIV, and its comorbidities. The post-translational carbonylation of proteins results from oxidative stress, and circulating protein carbonyls may reflect this. In this cross-sectional analysis, we evaluated the associations between protein carbonyls and a panel of soluble biomarkers of neuronal injury and inflammation in plasma (N = 45) and cerebrospinal fluid (CSF, n = 32) with structural brain MRI. The volume of abnormal WM was normalized for the total WM volume (nAWM). In this multisite project, all regression models were adjusted for the scanner. The candidate covariates included demographics, HIV disease characteristics, and comorbidities. Participants were PWH on virally suppressive antiretroviral therapy (ART) and were mostly white (64.4%) men (88.9%), with a mean age of 56.8 years. In unadjusted analyses, more nAWM was associated with higher plasma protein carbonyls (p = 0.002) and higher CCL2 (p = 0.045). In the adjusted regression models for nAWM, the association with plasma protein carbonyls remained significant (FDR p = 0.018). Protein carbonyls in plasma may be a valuable biomarker of oxidative stress and its associated adverse health effects, including within the central nervous system. If confirmed, these findings would support the hypothesis that reducing oxidative stress could treat or prevent WM injury in PWH.

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.

Antiretroviral Therapy Intensification for Neurocognitive Impairment in Human Immunodeficiency Virus

BACKGROUND

Neurocognitive impairment (NCI) in people with HIV (PWH) on antiretroviral therapy (ART) is common and may result from persistent HIV replication in the central nervous system.

METHODS

A5324 was a randomized, double-blind, placebo-controlled, 96-week trial of ART intensification with dolutegravir (DTG) + MVC, DTG + Placebo, or Dual - Placebo in PWH with plasma HIV RNA <50 copies/mL on ART and NCI. The primary outcome was the change on the normalized total z score (ie, the mean of individual NC test z scores) at week 48.

RESULTS

Of 357 screened, 191 enrolled: 71% male, 51% Black race, 22% Hispanic ethnicity; mean age 52 years; mean CD4+ T-cells 681 cells/µL. Most (65%) had symptomatic HIV-associated NC disorder. Study drug was discontinued due to an adverse event in 15 (8%) and did not differ between arms (P = .17). Total z score, depressive symptoms, and daily functioning improved over time in all arms with no significant differences between them at week 48 or later. Adjusting for age, sex, race, study site, efavirenz use, or baseline z score did not alter the results. Body mass index modestly increased over 96 weeks (mean increase 0.32 kg/m2, P = .006) and did not differ between arms (P > .10).

CONCLUSIONS

This is the largest, randomized, placebo-controlled trial of ART intensification for NCI in PWH. The findings do not support empiric ART intensification as a treatment for NCI in PWH on suppressive ART. They also do not support that DTG adversely affects cognition, mood, or weight.

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 [...].

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 Aβ42; 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.

Beyond the Syndemic of Opioid Use Disorders and HIV: The Impact of Opioids on Viral Reservoirs

People with HIV are more likely to have opioid use disorder and to be prescribed opioids for chronic pain than the general population; however, the effects of opioids on the immune system and HIV persistence have not been fully elucidated. Opioids may affect HIV reservoirs during their establishment, maintenance, and reactivation by enhancing HIV infectivity and replication due to upregulation of co-receptors and impairment of innate antiviral responses. Opioids may also modulate immune cell functioning and microbial translocation and can reverse viral latency. In this review, we summarize the current findings for and against the modulating effects of opioids on HIV cellular and anatomical reservoirs, highlighting the current limitations that affect in vitro, ex vivo, and in vivo studies in the field. We propose further research targets and potential strategies to approach this topic.

Cerebrospinal fluid levels of 5-HIAA and dopamine in people with HIV and depression

Depression is a common illness in people with HIV (PWH) and is associated with substantial morbidity and mortality. The mechanisms that underpin depression in PWH remain incompletely elucidated, and more research is therefore needed to develop effective treatments. One hypothesis is that neurotransmitter levels may be altered. These levels could be influenced by the chronic inflammation and viral persistence that occurs in PWH. We examined a panel of cerebrospinal fluid (CSF) neurotransmitters in PWH on suppressive antiretroviral therapy (ART), many of whom had a current depression diagnosis. CSF monoamine neurotransmitters and their metabolites were measured from participants in studies at the Emory Center for AIDS Research (CFAR). Only participants on stable ART with suppressed HIV RNA from both plasma and CSF were analyzed. Neurotransmitter levels were measured with high-performance liquid chromatography (HPLC). Neurotransmitters and their metabolites included dopamine (DA), homovanillic acid (HVA, a major metabolite of dopamine), serotonin (5-HT), 5-hydroxyindole-3-acetic acid (5-HIAA, a major metabolite of serotonin), and 4-hydroxy-3-methoxyphenylglycol (MHPG, a major metabolite of norepinephrine). Multivariable logistic regression was used to evaluate factors associated with depression. There were 79 PWH with plasma and CSF HIV RNA levels < 200 copies/mL at the time of the visit, and 25 (31.6%) carried a current diagnosis of depression. Participants with depression were significantly older (median age 53 years versus 47 years, P = 0.014) and were significantly less likely to be African American (48.0% versus 77.8%, P = 0.008). Participants with depression had significantly lower dopamine levels (median 0.49 ng/mL versus 0.62 ng/mL, P = 0.03) and significantly lower 5-HIAA levels (median 12.57 ng/mL versus 15.41 ng/mL, P = 0.015). Dopamine and 5-HIAA were highly correlated. In the multivariable logistic regression models, lower 5-HIAA was significantly associated with the depression diagnosis when accounting for other significant demographic factors. The associations between lower 5-HIAA, lower dopamine, and depression in PWH suggest that altered neurotransmission may contribute to these comorbid conditions. However, the effects of antidepressants on neurotransmitters cannot be ruled out as a factor in the 5-HIAA results.

CROI 2023: Neuropsychiatric Complications in People With HIV

The 2023 Conference on Retroviruses and Opportunistic Infections (CROI) featured new and impactful findings about neuropsychiatric complications in people with HIV and other infections. Reports included new evidence of (a) the importance of myeloid cells in the pathogenesis of HIV disease in the central nervous system, including as an HIV reservoir; (b) eukaryotic and prokaryotic viruses in cerebrospinal fluid during suppressive antiretroviral therapy; (c) the influence of sex on pathogenesis, including in novel neuropsychiatric biotypes identified by machine learning and other methods;(d) premature aging in people with HIV, including the brain-age gap observed on magnetic resonance imaging; (e) cellular and soluble biomarkers of neuropsychiatric complications in people with HIV; and (f) the neurotoxicity of certain antiretroviral drugs. This review summarizes these and other new findings and highlights new research directions for the neuro-HIV field.

Anemia and Erythrocyte Indices Are Associated With Neurocognitive Performance Across Multiple Ability Domains in Adults With HIV

BACKGROUND

Anemia is linked to neurocognitive impairment (NCI) in people with HIV (PWH), but its impact within specific ability domains, and in diverse populations with HIV, is uncertain.

METHODS

Participants included 1339 PWH enrolled in observational HIV cohort studies with a mean of 3 comprehensive neurocognitive assessments over 30 months. Global and domain-specific neurocognitive function were assessed by the global deficit score and domain deficit score (GDS and DDS, respectively) or as GDS-defined or DDS-defined NCI (GDS ≥ 0.5, DDS > 0.5). Time-dependent associations of anemia or red-cell indices with neurocognitive function were evaluated by multivariable regression.

RESULTS

The mean age at entry was 43.6 years (85% male, 23.9% Hispanic, 16.7% African ancestry by self-report, and 69.8% virally suppressed). Anemia occurred at entry in 297 (22.2%) and developed subsequently in another 129 (9.6%). Anemia (present in 26.8% of cognitively impaired PWH at entry) and lower hemoglobin were associated with higher (worse) GDS values; the association for anemia persisted after multivariable adjustment and in virally suppressed persons ( P < 0.0001). Anemia was also associated with reduced processing speed, motor function, learning, delayed recall, working memory (all P < 0.01), executive function ( P = 0.021), and verbal fluency ( P = 0.035), and these findings persisted in longitudinal analyses (adjusted P < 0.01 for all domains, except verbal fluency). Higher mean corpuscular volume and mean corpuscular hemoglobin were associated with less impairment in learning and recall (all P < 0.05).

CONCLUSIONS

Anemia in diverse and virally suppressed PWH associates with reduced neurocognitive performance in multiple domains, cross-sectionally and over time. The impact of identifying and treating anemia to prevent or slow neurocognitive decline in PWH should be prospectively evaluated.

Higher Levels of Cerebrospinal Fluid and Plasma Neurofilament Light in Human Immunodeficiency Virus-Associated Distal Sensory Polyneuropathy

BACKGROUND

Neurofilament light (NFL) chain concentrations, reflecting axonal damage, are seen in several polyneuropathies but have not been studied in human immunodeficiency virus (HIV) distal sensory polyneuropathy (DSP). We evaluated NFL in cerebrospinal fluid (CSF) and plasma in relation to DSP in people with HIV (PWH) from 2 independent cohorts and in people without HIV (PWoH).

METHODS

Cohort 1 consisted of PWH from the CHARTER Study. Cohort 2 consisted of PWH and PWoH from the HIV Neurobehavioral Research Center (HNRC). We evaluated DSP signs and symptoms in both cohorts. Immunoassays measured NFL in CSF for all and for plasma as well in Cohort 2.

RESULTS

Cohort 1 consisted of 111 PWH, mean ± SD age 56.8 ± 8.32 years, 15.3% female, 38.7% Black, 49.6% White, current CD4+ T-cells (median, interquartile range [IQR]) 532/µL (295, 785), 83.5% with plasma HIV RNA ≤50 copies/mL. Cohort 2 consisted of 233 PWH of similar demographics to PWH in Cohort 1 but also 51 PWoH, together age 58.4 ± 6.68 years, 41.2% female, 18.0% Black, Hispanic, non-Hispanic White 52.0%, 6.00% White. In both cohorts of PWH, CSF and plasma NFL were significantly higher in both PWH with DSP signs. Findings were similar, albeit not significant, for PWoH. The observed relationships were not explained by confounds.

CONCLUSIONS

Both plasma and CSF NFL were elevated in PWH and PWoH with DSP. The convergence of our findings with others demonstrates that NFL is a reliable biomarker reflecting peripheral nerve injury. Biomarkers such as NFL might provide, validate, and optimize clinical trials of neuroregenerative strategies in HIV DSP.

PKR-like ER kinase (PERK) Haplotypes Are Associated with Depressive Symptoms in People with HIV

Background

Depression is a debilitating and difficult-to-treat condition in people with HIV (PWH) despite viral suppression on antiretroviral therapy (ART). Depression is associated with activation of the PKR-like ER kinase (PERK) pathway, which regulates protein synthesis in response to metabolic stress. We evaluated common PERK haplotypes that influence PERK expression in relation to depressed mood in PWH.

Methods

PWH from 6 research centers were enrolled in the study. Genotyping was conducted using targeted sequencing with TaqMan. The major PERK haplotypes A, B, and D were identified. Depressive symptom severity was assessed using the Beck Depression Inventory-II (BDI-II). Covariates including genetically-defined ancestry, demographics, HIV disease/treatment parameters and antidepressant treatments were assessed. Data were analyzed using multivariable regression models.

Results

A total of 287 PWH with a mean (SD) age of 57.1±7.8 years were enrolled. Although the largest ethnic group was non-Hispanic white (n=129, 45.3%), African-American (n=124, 43.5%) and Hispanic (n=30, 10.5%) made up over half the sample. 20.3% were female and 96.5% were virally suppressed. Mean BDI-II was 9.6±9.5, and 28.9% scored above the cutoff for mild depression (BDI-II>13). PERK haplotype frequencies were AA57.8%, AB25.8%, AD 10.1%, and BB4.88%. PERK haplotypes were differentially represented according to genetic ancestry (p=6.84e-6). BDI-II scores were significantly higher in participants with the AB haplotype (F=4.45, p=0.0007).This finding was robust to consideration of potential confounds.

Conclusion

PERK haplotypes were associated with depressed mood in PWH.Consequently, pharmacological targeting of PERK-related pathways might amelioratedepression 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.

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.

Time of Day Influences Concentrations of Total Protein and Albumin in Cerebrospinal Fluid in HIV

The accumulation of soluble proteins and metabolites during wakefulness and their clearance during sleep via the glymphatic system occurs in healthy adults and is disturbed in some neurological conditions. Such diurnal variations in the cerebrospinal fluid (CSF) proteins produced outside the central nervous system and entering via the blood-brain barrier (BBB) have not been evaluated in people with HIV (PWH). CSF and blood were collected in 165 PWH at six US centers between 2003 and 2007. The time of collection was compared to CSF albumin, globulin, and total protein concentrations using bivariate and multivariate regression. Participants all took antiretroviral therapy (ART) and were mostly middle-aged (median age 44.0 years) men (78.8%), with AIDS (77.0%), plasma HIV RNA ≤ 200 copies/mL (75.8%), and immune recovery (median CD4+ T-cell count 414/µL). CSF was collected at median 1:10 p.m. (range 9:00 a.m. to 5:20 p.m.) and within a median of 15 min of blood collection. A later time of CSF collection was associated with higher total protein (p = 0.0077) and albumin (p = 0.057) in CSF but not in serum, and was additionally associated with higher CSF globulin (p = 0.013). The glymphatic clearance of albumin, globulin, and total protein is preserved in PWH. The analyses of soluble biomarkers in CSF should account for the time of collection.

Current Challenges and Solutions for Clinical Management and Care of People with HIV: Findings from the 12th Annual International HIV and Aging Workshop

People with HIV on combination antiretroviral therapy (ART) have longer life expectancy and are increasingly experiencing age-related comorbidities. Thus, aging with HIV has become a central issue in clinical care and research, which has been particularly challenging with the intersection of the ongoing coronavirus (COVID)-19 pandemic. Since 2009, the International Workshop on HIV and Aging has served as a multidisciplinary platform to share research findings from cross-disciplinary fields along with community advocates to address critical issues in HIV and aging. In this article, we summarize the key oral presentations from the 12th Annual International Workshop on HIV and Aging, held virtually on September 23rd and 24th, 2021. The topics ranged from basic science research on biological mechanisms of aging to quality of life and delivery of care under the COVID-19 pandemic. This workshop enriched our understanding of HIV and aging under the COVID-19 pandemic, identified challenges and opportunities to combat the impact of COVID-19 on HIV communities, and also provided updated research and future directions of the field to move HIV and aging research forward, with the ultimate goal of successful aging for older people with HIV.

Lessons for Understanding Central Nervous System HIV Reservoirs from the Last Gift Program

PURPOSE OF REVIEW

Deep tissue HIV reservoirs, especially within the central nervous system (CNS), are understudied due to the challenges of sampling brain, spinal cord, and other tissues. Understanding the cellular characteristics and viral dynamics in CNS reservoirs is critical so that HIV cure trials can address them and monitor the direct and indirect effects of interventions. The Last Gift program was developed to address these needs by enrolling altruistic people with HIV (PWH) at the end of life who agree to rapid research autopsy.

RECENT FINDINGS

Recent findings from the Last Gift emphasize significant heterogeneity across CNS reservoirs, CNS compartmentalization including differential sensitivity to broadly neutralizing antibodies, and bidirectional migration of HIV across the blood-brain barrier. Our findings add support for the potential of CNS reservoirs to be a source of rebounding viruses and reseeding of systemic sites if they are not targeted by cure strategies. This review highlights important scientific, practical, and ethical lessons learned from the Last Gift program in the context of recent advances in understanding the CNS reservoirs and key knowledge gaps in current research.

CROI 2022: neurologic complications of HIV-1, SARS-CoV-2, and other pathogens

The 2022 Conference on Retroviruses and Opportunistic Infections featured new and important findings about the neurologic complications of HIV-1, COVID-19, and other infections. Long-term analyses identified that cognitive decline over time, phenotypic aging, and stroke are associated with various comorbidities in people with HIV. Neuroimaging studies showed greater neuroinflammation, white matter damage, demyelination, and overall brain aging in people with chronic HIV infection. Childhood trauma and exposure to environmental pollutants contribute to these neuroimaging findings. Studies of blood and cerebrospinal fluid biomarkers showed that systemic inflammation, neurodegeneration, endothelial activation, oxidative stress, and iron dysregulation are associated with worse cognition in people with HIV. Some animal studies focused on myeloid cells of the central nervous system, but other animal and human studies showed that lymphoid cells also contribute to HIV neuropathogenesis. The deleterious central nervous system effects of polypharmacy and anticholinergic drugs in people with HIV were demonstrated. In contrast, a large randomized controlled trial showed that integrase strand transfer inhibitor therapy was not associated with neurotoxicity. Studies of cryptococcal meningitis demonstrated he cost-effectiveness of single high-dose liposomal amphotericin and the prognostic value of the cryptococcal antigen lateral flow assay. People hospitalized with COVID-19 had more anxiety over time after discharge. The SARS-CoV-2 nucleocapsid antigen is present in cerebrospinal fluid in the absence of viral RNA. Systemic inflammation, astrocyte activation, and tryptophan metabolism pathways are associated with post-COVID-19 neurologic syndromes. Whether these processes are independent or intertwined during HIV-1 and COVID-19 infections requires further study.

Cognitive and Physiologic Reserve Independently Relate to Superior Neurocognitive Abilities in Adults Aging With HIV

BACKGROUND

To investigate joint contributions of cognitive and physiologic reserve to neurocognitive SuperAging in older persons with HIV (PWH).

METHODS

Participants included 396 older PWH (age range: 50-69 years) who completed cross-sectional neuropsychological and neuromedical evaluations. Using published criteria, participants exhibiting global neurocognition within normative expectations of healthy 25-year-olds were classified as SuperAgers (SA; n = 57). Cognitively normal (CN; n = 172) and impaired (n = 167) participants were classified with chronological age-based norms. Cognitive reserve was operationalized with an estimate of premorbid verbal intelligence, and physiologic reserve was operationalized with a cumulative index of 39 general and HIV-specific health variables. Analysis of variance with confirmatory multinomial logistic regression examined linear and quadratic effects of cognitive and physiologic reserve on SA status, adjusting for chronological age, depression, and race/ethnicity.

RESULTS

Univariably, SA exhibited significantly higher cognitive and physiologic reserve compared with CN and cognitively impaired ( d s ≥ 0.38, p s < 0.05). Both reserve factors independently predicted SA status in multinomial logistic regression; higher physiologic reserve predicted linear increases in odds of SA, and higher cognitive reserve predicted a quadratic "J-shaped" change in odds of SA compared with CN (ie, odds of SA > CN only above 35th percentile of cognitive reserve).

CONCLUSIONS

Each reserve factor uniquely related to SA status, which supports the construct validity of our SA criteria and suggests cognitive and physiologic reserve reflect nonoverlapping pathways of neuroprotection in HIV. Incorporation of proxy markers of reserve in clinical practice may improve characterization of age-related cognitive risk and resilience among older PWH, even among PWH without overt neurocognitive impairment.

Neuropathic pain correlates with worsening cognition in people with human immunodeficiency virus

Neuropathic pain and cognitive impairment are among the HIV-related conditions that have most stubbornly resisted amelioration by virally suppressive antiretroviral therapy. Overlaps between the regional brain substrates and mechanisms of neuropathic pain and cognitive disorders are increasingly recognized, yet no studies have examined the longitudinal relationship between these two disorders. Participants in the prospective, observational CNS HIV AntiRetroviral Therapy Effects Research (CHARTER) cohort underwent standardized clinical evaluations for clinical examination findings of distal sensory polyneuropathy, reporting distal neuropathic pain and neurocognitive performance at study entry (baseline) and an average of 12 years later. Change in neuropathic pain and neuropathy status from baseline to follow-up was by self-report and repeat examination, and change in neurocognitive performance was assessed using a previously published summary regression-based change score. Relationships between incident or worsened neuropathic pain and neurocognitive change were evaluated using uni- and multivariable regressions, including age at baseline and other relevant covariates. Participants were 385 people with HIV, 91 (23.6%) females, mean ± standard deviation (SD) age at baseline 43.5 (7.81) years, ethnicity 44.9% African American, 10.6% Hispanic, 42.6% non-Hispanic white and 1.82% other. Baseline median (interquartile range) nadir CD4 was 175 (34 309) cells/µl and current CD4 was 454 (279 639). Incident or worsened distal neuropathic pain occurred in 98 (25.5%) over the follow-up period. People with HIV with incident or worsened distal neuropathic pain had significantly worsened neurocognitive performance at follow-up compared to those without incident or worsened distal neuropathic pain (summary regression-based change score mean ± SD -0.408 ± 0.700 versus -0.228 ± 0.613; P = 0.0158). This effect remained significant when considering viral suppression on antiretroviral therapy, incident diabetes and other covariates as predictors. Overall neurocognitive change related to neuropathic pain was driven primarily by changes in the domains of executive function and speed of information processing. Those with incident distal neuropathy signs did not have neurocognitive worsening, nor did individuals who used opioid analgesics or other pain-modulating drugs such as amitriptyline. Worsened neurocognitive performance in people with HIV was associated with worsened neuropathic pain but not with changes in physical signs of neuropathy, and this was not attributable to therapies for pain or depression or to differences in viral suppression. This finding implies that incident or worsened pain may signal increased risk for neurocognitive impairment, and deserves more investigation, particularly if better pain management might stabilize or improve neurocognitive performance.

Identification of Youthful Neurocognitive Trajectories in Adults Aging with HIV: A Latent Growth Mixture Model

Despite the neurocognitive risks of aging with HIV, initial cross-sectional data suggest a subpopulation of older people with HIV (PWH) possess youthful neurocognition (NC) characteristic of SuperAgers (SA). Here we characterize longitudinal NC trajectories of older PWH and their convergent validity with baseline SA status, per established SuperAging criteria in PWH, and baseline biopsychosocial factors. Growth mixture modeling (GMM) identified longitudinal NC classes in 184 older (age ≥ 50-years) PWH with 1–5 years of follow-up. Classes were defined using ‘peak-age’ global T-scores, which compare performance to a normative sample of 25-year-olds. 3-classes were identified: Class 1_{Stable Elite} (n = 31 [16.8%], high baseline peak-age T-scores with flat trajectory); Class 2_{Quadratic Average} (n = 100 [54.3%], intermediate baseline peak-age T-scores with u-shaped trajectory); Class 3_{Quadratic Low} (n = 53 [28.8%], low baseline peak-age T-scores with u-shaped trajectory). Baseline predictors of Class 1_{Stable Elite} included SA status, younger age, higher cognitive and physiologic reserve, and fewer subjective cognitive difficulties. This GMM analysis supports the construct validity of SuperAging in older PWH through identification of a subgroup with longitudinally-stable, youthful neurocognition and robust biopsychosocial health.

Neopterin Relates to Lifetime Depression in Older Adults With HIV on Suppressive Antiretroviral Therapy

BACKGROUND

Chronic inflammation contributes to the pathogenesis of depression in persons with HIV (PWH). Neopterin, a biomarker of HIV-related immune activation that partially normalizes with antiretroviral therapy (ART), correlates with major depressive disorder (MDD) and subclinical depressive symptoms in persons without HIV and acutely infected, young PWH. The sensitivity of neopterin, however, to both lifetime and current depression is poorly understood in older PWH on suppressive ART.

METHODS

Participants were 70 PWH and 35 persons without HIV (HIV-) who were at least 50 years old and completed standardized neurobehavioral and neuromedical assessments. Depressive symptoms in the past 2 weeks, measured with the Beck Depression Inventory-II (BDI-II), and lifetime MDD diagnoses, defined as meeting Diagnostic and Statistical Manual of Mental Disorders-IV criteria for a depressive episode at any point in one's lifetime, were separately modeled as a function of plasma neopterin levels in the full sample and by HIV serostatus.

RESULTS

Compared with HIV- adults, PWH had higher neopterin levels (P < 0.001) and BDI-II scores (P < 0.01) and were more likely to have lifetime MDD (P < 0.01). Higher neopterin related to lifetime MDD, but only in PWH, even after controlling for clinically relevant comorbidities and treatment factors in logistic regression (odds ratio = 3.11, P = 0.002). Higher neopterin correlated with higher BDI-II scores in the full sample (rs = 0.25; P = 0.010), but not within either group (PWH: rs = 0.03, P = 0.819; HIV-: rs = 0.09, P = 0.588).

CONCLUSION

Neopterin was associated with lifetime MDD, but not current depressive symptoms in older PWH on suppressive ART. This may reflect a legacy of inflammation-related disruptions to amino acid metabolism and neurotransmitter synthesis, similar to prior observations. Identification of biopsychosocial and resilience factors underlying the null association between neopterin and current depression in older PWH is warranted.

A Haptoglobin Exon Copy Number Variant Associates With HIV-Associated Neurocognitive Impairment in European and African-Descent Populations

A common two-exon deletion distinguishes the gene encoding the free hemoglobin capturing protein—haptoglobin (HP)–into two alleles: HP1 and HP2. To evaluate the impact of this copy number variant (CNV) on neurocognitive impairment (NCI) in people living with HIV, we imputed this variant in 432 European-descent (EUR) and 491 African-descent (AFR) participants from the CNS HIV Antiretroviral Therapy Effects Research Study using an optimized imputation pipeline and evaluated its associations with NCI. At baseline, in AFR, the HP2 allele decreased the odds of NCI (defined by a global deficit score, GDS, ⩾0.5; Odds Ratio, OR = 0.584, p = 0.022). However, in EUR, HP2 increased the odds (OR = 2.081, p = 0.040) of NCI suggesting a detrimental effect. These effects were extended to longitudinal analyses using repeated measurements where the protective effect of the HP2 allele in AFR became marginally significant (p = 0.054) and in EUR the detrimental effect increased in significance (p = 0.037). In EUR, the HP2 allele slightly reduced the risk of NCI over time (OR = 0.028 per allele per year, p = 0.024). Further analyses of cognitive domain-specific impairment revealed that the HP-NCI effect was based on changes in learning, speed of information processing, and verbal domains over time differing by ancestry groups. Overall, these findings suggest that these functional HP CNV alleles influence the likelihood of NCI and contribute to changes in neurocognitive function over time in people living with HIV.

A Cross-Sectional Study to Evaluate the Effects of Age and Duration of HIV Infection on Anxiety and Depression in Cisgender Men

This observational cross-sectional study of 152 people with HIV (PWH) examined the effects of age and estimated duration of HIV infection (EDI) on depressive and anxiety symptoms. All participants were cisgender men and completed the Profile of Moods State (POMS), a self-report inventory of current (i.e., past week) mood states. Overall, study results confirmed higher levels of anxiety and depression in PWH compared to individuals without HIV. Age group (< 50 or ≥ 50 years) moderated the effect of EDI (< 3 or ≥ 3 years) on mood disturbance. Specifically, younger PWH with early diagnosed infection exhibited the highest levels of depression and anxiety, whereas depression and anxiety were attenuated in older PWH with early infection such that their POMS scores did not significantly differ from the HIV-negative and chronically HIV-infected groups. Despite the small sample size and other important limitations in our study design, our preliminary findings confirm previous observations that older people may have some adaptive ability to better handle the acute psychological stressors associated with recent HIV infection.

Race-Dependent Association of Single-Nucleotide Polymorphisms in TrkB Receptor in People Living with HIV and Depression

Human immunodeficiency virus (HIV)-associated cognitive disorders (HAND) is characterized by impaired motor and intellectual functions, as well as mood disorders. Brain-derived neurotrophic factor and its receptor TrkB (or NTRK2) mediate the efficacy of antidepressant drugs. Genomic studies of BDNF/TrkB have implicated common single-nucleotide polymorphisms in the pathology of depression. In the current study, we investigated whether single-nucleotide polymorphisms (SNPs) (rs1212171, rs1439050, rs1187352, rs1778933, rs1443445, rs3780645, rs2378672, and rs11140800) in the NTRK2 has a functional impact on depression in HIV-positive subjects. We have utilized the Central Nervous System (CNS) HIV Antiretroviral Therapy Effects Research (CHARTER) cohort. Our methods explored the univariate associations of these SNPs with clinical (current and lifetime) diagnosis of depression via chi-square. The distribution of alleles was significantly different for African-Americans and Caucasians (non-Hispanic) for several SNPs, so our regression analyses included both "statistical controls" for race group and models for each group separately. Finally, we applied a method of simultaneous analysis of associations, estimating the mutually shared information across a system of variables, separately by race group. Our results indicate that there is no significant association between clinical diagnosis of major depression and these SNPs for either race group in any analysis. However, we identified that the SNP associations varied by race group and sex.

Soluble Biomarkers of Cognition and Depression in Adults with HIV Infection in the Combination Therapy Era

PURPOSE OF REVIEW

Cognitive impairment and depression continue to be common among people with HIV (PWH) in the combination antiretroviral therapy (ART) era. A better understanding of the biological mechanisms that may underpin these disorders is needed. The purpose of this review is to describe published findings on soluble biomarkers from blood and cerebrospinal fluid (CSF) that have been associated with either cognition or depression among PWH in the setting of ART.

RECENT FINDINGS

Several biomarkers, including those that reflect viral persistence, monocyte/macrophage activation, and other processes, are associated with cognition and depressive symptoms. Some but not all results have been consistent across multiple studies. More research has been published on biomarkers of cognition relative to biomarkers of depression (particularly from CSF). More studies are needed that investigate multiple biomarkers to understand the role of distinct but additive pathways in these disorders and to guide the development of new therapies.

Low-Level HIV RNA in Cerebrospinal Fluid and Neurocognitive Performance: A Longitudinal Cohort Study

BACKGROUND

Cognitive complications persist in persons with HIV during suppressive antiretroviral therapy (ART). Low levels of HIV during ART could contribute to these complications. In this study, we measured cerebrospinal fluid (CSF) HIV using a single-copy assay (SCA) to investigate a possible relationship between low-level HIV and cognition.

DESIGN/METHODS

SCA data were analyzed from 3 consecutively paired CSF-plasma specimens collected over a mean of 456 days from 96 participants on suppressive ART. Using mixed models, the presence of CSF HIV by SCA as a risk factor for worse neurocognitive performance was examined.

RESULTS

At baseline on the SCA, 45.8% of participants had detectable plasma HIV RNA (median 8 copies/mL and interquartile range = 3-17 among detectable values) and 17.7% had detectable CSF HIV RNA (median CSF concentration= 3 copies/mL and interquartile range= 2-13 among detectable values). The frequency of CSF HIV RNA detection declined over time in CSF (P = 0.018) with a trend toward decline in plasma (P = 0.064). Detectable CSF HIV RNA during the study was associated with worse performance in the domains of recall (P = 0.014) and motor (P = 0.040) and a trend with worse overall global performance (P = 0.078). Integrase inhibitor use, although very infrequent in this cohort, was associated with better performance in 2 domains.

CONCLUSIONS

Low-level CSF HIV RNA declines with time but is associated with worse cognitive performance in 2 domains. Additional research is needed to better understand the relationship between HIV RNA persistence during long-term ART and central nervous system complications in persons with HIV.

Higher CSF Ferritin Heavy-Chain (Fth1) and Transferrin Predict Better Neurocognitive Performance in People with HIV

HIV-associated neurocognitive disorder (HAND) remains prevalent despite antiretroviral therapy and involves white matter damage in the brain. Although iron is essential for myelination and myelin maintenance/repair, its role in HAND is largely unexplored. We tested the hypotheses that cerebrospinal fluid (CSF) heavy-chain ferritin (Fth1) and transferrin, proteins integral to iron delivery and myelination, are associated with neurocognitive performance in people with HIV (PWH). Fth1, transferrin, and the pro-inflammatory cytokines TNF-α and IL-6 were quantified in CSF at baseline (entry) in 403 PWH from a prospective observational study who underwent serial, comprehensive neurocognitive assessments. Associations of Fth1 and transferrin with Global Deficit Score (GDS)-defined neurocognitive performance at baseline and 30-42 months of follow-up were evaluated by multivariable regression. While not associated with neurocognitive performance at baseline, higher baseline CSF Fth1 predicted significantly better neurocognitive performance over 30 months in all PWH (p < 0.05), in PWH aged < 50 at 30, 36, and 42 months (all p < 0.05), and in virally suppressed PWH at all three visit time-points (all p < 0.01). Higher CSF transferrin was associated with superior neurocognitive performance at all visits, primarily in viremic individuals (all p < 0.05). All associations persisted after adjustment for neuro-inflammation. In summary, higher CSF Fth1 is neuroprotective over prolonged follow-up in all and virally suppressed PWH, while higher CSF transferrin may be most neuroprotective during viremia. We speculate that higher CSF levels of these critical iron-delivery proteins support improved myelination and consequently, neurocognitive performance in PWH, providing a rationale for investigating their role in interventions to prevent and/or treat HAND.

Pharmacokinetics and antiviral activity of cabotegravir and rilpivirine in cerebrospinal fluid following long-acting injectable administration in HIV-infected adults

Background

Long-acting (LA) formulations of cabotegravir, an HIV integrase inhibitor, and rilpivirine, an NNRTI, are in development as monthly or 2 monthly intramuscular (IM) injections for maintenance of virological suppression.

Objectives

To evaluate cabotegravir and rilpivirine CSF distribution and HIV-1 RNA suppression in plasma and CSF in HIV-infected adults participating in a substudy of the Phase 2b LATTE-2 study (NCT02120352).

Methods

Eighteen participants receiving cabotegravir LA 400 mg + rilpivirine LA 600 mg IM [every 4 weeks (Q4W), n = 3] or cabotegravir LA 600 mg + rilpivirine LA 900 mg IM [every 8 weeks (Q8W), n = 15] with plasma HIV-1 RNA <50 copies/mL enrolled. Paired steady-state CSF and plasma concentrations were evaluable in 16 participants obtained 7 (±3) days after an injection visit. HIV-1 RNA in CSF and plasma were assessed contemporaneously using commercial assays.

Results

Median total CSF concentrations in Q4W and Q8W groups, respectively, were 0.011 μg/mL and 0.013 μg/mL for cabotegravir (0.30% and 0.34% of the paired plasma concentrations) and 1.84 ng/mL and 1.67 ng/mL for rilpivirine (1.07% and 1.32% of paired plasma concentrations). Cabotegravir and rilpivirine total CSF concentrations exceeded their respective in vitro EC₅₀ for WT HIV-1 (0.10 ng/mL and 0.27 ng/mL, respectively). All 16 participants had HIV-1 RNA <50 copies/mL in plasma and CSF, and 15 of 16 participants had HIV-1 RNA <2 copies/mL in CSF.

Conclusions

A dual regimen of cabotegravir LA and rilpivirine LA achieved therapeutic concentrations in the CSF resulting in effective virological control in CSF.

Switching to Tenofovir Alafenamide in Elvitegravir-Based Regimens: Pharmacokinetics and Antiviral Activity in Cerebrospinal Fluid

BACKGROUND

Tenofovir alafenamide fumarate (TAF) co-formulated with elvitegravir (EVG; E), cobicistat (C), and emtricitabine (F), a recommended antiretroviral regimen, was evaluated for distribution and antiviral activity in cerebrospinal fluid (CSF) as well as neurocognitive (NC) performance change in participants switching from E/C/F/tenofovir disoproxil fumarate (TDF) to E/C/F/TAF.

METHODS

This was a 24-week, single-arm, open-label study in treatment-experienced adults living with human immunodeficiency virus (HIV). Nine participants switched from E/C/F/TDF (150/150/200/300 mg once daily) to E/C/F/TAF (150/150/200/10 mg once daily) at week 12. CSF and total plasma concentrations of EVG, TDF, TAF, tenofovir (TFV), and HIV RNA levels were measured at baseline and week 24. NC performance was estimated by the Montreal Cognitive Assessment.

RESULTS

EVG concentrations in CSF and the CSF:plasma ratio remained stable (P = .203) over time. Following the switch, TFV concentrations in CSF and plasma declined (P = .004), although the TFV CSF:plasma ratio increased (P = .004). At week 24, median TAF plasma concentration was 11.05 ng/mL (range, 2.84-147.1 ng/mL) 2 hours postdose but was below assay sensitivity 6 hours after dosing. TAF was below assay sensitivity in all CSF specimens. HIV RNA was ≤40 copies/mL in all CSF and plasma specimens. Three participants (33%) had NC impairment at baseline and 2 (22%) remained impaired at week 24.

CONCLUSIONS

Switch to E/C/F/TAF was associated with reductions in TFV concentrations in CSF but stable EVG concentrations that exceeded the 50% inhibitory concentration for wild-type HIV, suggesting that EVG achieves therapeutic concentrations in the central nervous system. No virologic failure or significant NC changes were detected following the switch.

CLINICAL TRIALS REGISTRATION

NCT02251236.

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.

Cerebrospinal fluid CXCL10 is associated with the presence of low level CSF HIV during suppressive antiretroviral therapy

Surrogate markers of HIV central nervous system (CNS) persistence are needed because direct HIV measurements from the CNS require specialized protocols and are not always detectable or quantifiable. We analyzed paired plasma and CSF samples from people with HIV (PWH) on suppressive therapy (ART) with a validated HIV single copy RNA assay. Two potential markers of CNS persistence were measured (CXCL10 and sCD30). We then examined associations with CSF HIV RNA positivity in univariable and multivariable analyses. Among 66 individuals, 18.2% had detectable CSF HIV. Individuals who had detectable HIV in CSF had higher CSF CXCL10 concentrations (median 514 pg/ml versus median 317 pg/ml, p = 0.019), but did not have significantly different CSF sCD30 concentrations (median 7.5 ng/ml versus median 7.6 ng/ml, p = 0.78). In the multiple logistic analysis, both higher CSF CXCL10 (p = 0.038) and plasma HIV detectability (p = 0.035) were significantly associated with detectable CSF HIV. Both sCD30 and CXCL10 correlated positively with NfL and NSE, two neuronal markers. This study demonstrates that CSF CXCL10 concentrations reflect low level HIV CNS persistence despite virologic suppression on ART. Given that it is readily detectable and quantifiable, this chemokine may be a promising biomarker to evaluate HIV eradication therapies that target the CNS.

Social Isolation Is Linked to Inflammation in Aging People With HIV and Uninfected Individuals

BACKGROUND

Even in the era of suppressive antiretroviral therapy, people with HIV (PWH) suffer greater exposure to inflammation than their uninfected peers. Although poor social support and social isolation have been linked to systemic inflammation in the general population, it is not known whether this is true also among PWH.

METHODS

People with and without HIV infection were enrolled in a community-based, single-center study. Primary predictors were the Medical Outcomes Study Social Support Survey, and outcomes were a panel of inflammatory biomarkers (ICAM-1, MCP-1, IL-6, IL-8, IP-10, C-reactive protein, D-dimer, VEGF, sCD14, and uPAR) in blood plasma and cerebrospinal fluid (CSF).

RESULTS

PWH had worse positive social support (P = 0.0138) and affectionate support (P = 0.0078) than did HIV- individuals. A factor analysis was used to group the biomarkers into related categories separately for each fluid. Levels of 3 of the 4 plasma factors were significantly higher in PWH than HIV- (ps = 0.007, 0.001, and 0.0005, respectively). Levels of 1 of the 3 CSF factors also were significantly higher in PWH than HIV- (P = 0.0194). In the combined PWH and HIV- cohort, poorer social support was associated with higher levels of a factor in plasma loading on MCP-1, IL-8, and VEGF (P = 0.020) and with a CSF factor loading on MCP-1 and IL-6 (P = 0.006).

CONCLUSION

These results suggest that enhancing social support might be an intervention to reduce inflammation and its associated adverse outcomes among PWH.

CROI 2021: Neurologic Complications of HIV-1 Infection or COVID-19

The 2021 Conference on Retroviruses and Opportunistic Infections (CROI) featured a timely review of the neurologic complications of COVID-19 as well as new research findings on mechanisms by which SARS-CoV-2 may affect the brain. CROI included new and important findings about the neurologic complications of HIV-1, human polyomavirus 2 (also known as JC Virus), and cryptococcus. New long-term analyses of cognition in people with HIV-1 identified that cognitive decline over time is associated with multimorbidity, particularly diabetes, chronic lung disease, and vascular disease risk conditions. These conditions are associated with aging, and the question of whether people with HIV are at risk for premature aging was addressed by several reports. New findings from large analyses of resting state networks also provided valuable information on the structural and functional networks that are affected by HIV-1 infection and cognitive impairment. Several reports addressed changes after initiating or switching antiretroviral therapy (ART). Findings that will improve understanding of the biologic mechanisms of brain injury in people with HIV were also presented and included evidence that host (eg, myeloid activation, inflammation, and endothelial activation) and viral (eg, transcriptional activity and compartmentalization) factors adversely affect brain health. Other research focused on adjunctive therapies to treat HIV-1 and its complications in the central nervous system. This summary will review these and other findings in greater detail and identify key gaps and opportunities for researchers and clinicians.

A comprehensive data-driven analysis framework for detecting impairments in brain function networks with resting state fMRI in HIV-infected individuals on cART

Central nervous system (CNS) sequelae continue to be common in HIV-infected individuals despite combination antiretroviral therapy (cART). These sequelae include HIV-associated neurocognitive disorder (HAND) and virologic persistence in the CNS. Resting state functional magnetic resonance imaging (rsfMRI) is a widely used tool to examine the integrity of brain function and pathology. In this study, we examined 16 HIV-positive (HIV+) subjects and 12 age, sex, and race matched HIV seronegative controls (HIV-) whole-brain high-resolution rsfMRI along with a battery of neurocognitive tests. A comprehensive data-driven analysis of rsfMRI revealed impaired functional connectivity, with very large effect sizes in executive function, language, and multisensory processing networks in HIV+ subjects. These results indicate the potential of high-resolution rsfMRI in combination with advanced data analysis techniques to yield biomarkers of neural impairment in HIV.

Gut microbiota dysbiosis is associated with worse emotional states in HIV infection

The biological mechanisms underlying emotional distress in HIV infection are likely to be complex but remain understudied. We investigated whether dysbiotic signatures in the gut microbiome of persons living with HIV (PLWH) are associated with their emotional status. We retrospectively examined the gut microbiome and clinical evaluation of 129 adults (94 PLWH and 35 HIV-) enrolled at UC San Diego's HIV Neurobehavioral Research Program. A subset of participants (32 PLWH vs. 13 HIV-) underwent an emotional assessment using the NIH Toolbox Emotion Battery summarized by three composite scores (negative affect, social satisfaction, and psychological well-being). We then sequenced the 16S rDNA V3-V4 regions from stool and performed taxonomic assignment using CLC Microbial Genomics Module. The gut microbiota profiles were evaluated in relation to participants' emotional assessment. All analyses were done in R statistical software. We found that the relative abundance of aerotolerant bacteria was significantly higher in PLWH (p < 0.01) and was associated with a lifetime major depression diagnosis independently of HIV status (p = 0.05). Moreover, PLWH experienced significantly worse psychological well-being (p = 0.02), less social satisfaction (p = 0.03), and more negative affect (p = 0.02). Higher levels of aerotolerant bacteria were associated with worse psychological well-being (rho = -0.35, p = 0.02), less social satisfaction (r = - 0.42, p < 0.01), and more negative affect (rho = 0.46, p < 0.01). The association of aerotolerant bacteria with social satisfaction and negative affect was independent of HIV status (p < 0.05, for both). The over-representation of aerotolerant bacteria in the gut may reflect worse oxidative stress and barrier defects and may contribute to emotional distress during HIV infection.

Metabolic Risk Factors as Differential Predictors of Profiles of Neurocognitive Impairment Among Older HIV+ and HIV- Adults: An Observational Study

OBJECTIVE

Neurocognitive performance among older persons, including those living with HIV (people living with HIV [PLWH]), exhibits significant heterogeneity, suggesting subpopulations with differing profiles of neurocognitive impairment (NCI). Metabolic factors are associated with NCI, but their relationships to cluster-derived NCI profiles are unknown.

METHOD

Participants (144 PLWH and 102 HIV uninfected) aged 50+ years completed a neuropsychological battery assessing seven cognitive domains. Latent class analysis (LCA) identified NCI profiles separately by HIV serostatus and in a combined sample. Obtained classes were examined against the Montreal Cognitive Assessment (MoCA) and diagnoses of HIV-associated neurocognitive disorders (HAND). Multinomial regression identified metabolic predictors of classification.

RESULTS

LCA identified three latent classes in each participant sample: Class1Multidomain NCI (high probability of impairment across multiple domains), Class 2Learning & Recall NCI (high probability of impairment in learning and recall), and Class 3NC Unimpaired (low probability of NCI across all domains). Severity of NCI implied by classes corresponded with MoCA scores and HAND diagnoses. In analyses on the combined sample, compared to HIV-uninfected individuals, PLWH were more likely to be in Class1Multidomain NCI. Among PLWH, those with dyslipidemia and hypertension had greater odds of classification in Class 1Multidomain NCI while those with central obesity had higher odds of classification in Class 2Learning & Recall NCI; metabolic syndrome approached significance as a differential predictor. Regardless of HIV status, individuals with diabetes were more likely to be in Class 1Multidomain NCI.

CONCLUSIONS

Metabolic risk factors confer heightened risk of NCI in HIV infection. Interventions to reduce metabolic risk may improve neurocognitive outcomes among PLWH.

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.

Glucan rich nutrition does not increase gut translocation of beta-glucan

BACKGROUND

(1-3)-b-D-glucan (BDG) is a fungal cell wall component and, in the absence of invasive fungal infection, a novel biomarker for microbial translocation of endogenous fungal products from the gastrointestinal tract into systemic circulation. However, its value as a marker of fungal translocation is limited by a concern that plant BDG-rich food influences blood BDG levels.

METHODS

We conducted a pilot clinical trial to evaluate the impact of a standardised oral BDG challenge on blood BDG levels in participants with and without elevated microbial translocation. We enrolled 14 participants including 8 with HIV infection, 2 with advanced liver cirrhosis, and 4 healthy controls. After obtaining a baseline blood sample, participants received a standardised milkshake containing high levels of BDG followed by serial blood samples up to 8 hours after intake.

RESULTS

The standardised oral BDG challenge approach did not change the blood BDG levels over time in all participants. We found consistently elevated blood BDG levels in one participant with advanced liver cirrhosis and a single person with HIV with a low CD4 count of 201 cells/mm3 .

CONCLUSION

Our findings indicate that BDG blood levels were not influenced by plant origin BDG-rich nutrition in PWH, people with advanced liver cirrhosis, or healthy controls. Future studies are needed to analyse gut mycobiota populations in individuals with elevated blood BDG levels.

Nucleic acid oxidation is associated with biomarkers of neurodegeneration in CSF in people with HIV

OBJECTIVE

To determine whether oxidative stress in virologically suppressed people with HIV (PWH) may contribute to or result from neurodegeneration, we measured 7,8-dihydro-8-oxoguanine (8-oxo-dG), a marker of DNA damage due to oxidative stress, and markers of age-related neurodegeneration, specifically, reduced levels of CSF Aβ-42, and elevated CSF total tau and neurofilament light (NFL).

METHODS

This cross-sectional study prospectively enrolled participants at 6 US centers in the CNS HIV Antiretroviral Effects Research study. Inclusion criteria included HIV+ with a plasma level of HIV RNA ≤50 copies/mL. Exclusions included significant CNS confounding conditions. Measurements of total tau and Aβ-42 were performed by bead suspension array. NFL and 8-oxo-dG were measured using ELISA.

RESULTS

Participants were 53 PWH, mean age 55 (±9.3) years, 19% women, and 48% non-Hispanic White. Higher 8-oxo-dG correlated with markers of AD-related neurodegeneration including lower CSF Aβ-42 (r = -0.34; p = 0.012) and higher CSF NFL (r = 0.39; p = 0.0091) and total tau (r = 0.6696; p < 0.0001). Relationships remained after adjusting for demographic variables. Levels of protein carbonyls, a marker of protein oxidation, were not related to neurodegeneration markers.

CONCLUSIONS

Among virologically suppressed PWH, nucleic acid oxidation was associated with standard CSF biomarkers of neurodegeneration. Potential sources of oxidative stress in PWH include low-level HIV replication, inflammation, mitochondrial dysfunction, and specific antiretroviral drugs. Results suggest that the higher levels of oxidative stress among PWH may play a role in neurodegeneration.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that among virologically suppressed PWH, nucleic acid oxidation is associated with standard CSF biomarkers of neurodegeneration.