Sex differences in HIV-associated cognitive impairment

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

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

People with HIV exhibit spectrally distinct patterns of rhythmic cortical activity serving cognitive flexibility

Despite effective antiretroviral therapy, cognitive impairment remains prevalent among people with HIV (PWH) and decrements in executive function are particularly prominent. One component of executive function is cognitive flexibility, which integrates a variety of executive functions to dynamically adapt one's behavior in response to changing contextual demands. Though substantial work has illuminated HIV-related aberrations in brain function, it remains unclear how the neural oscillatory dynamics serving cognitive flexibility are affected by HIV-related alterations in neural functioning. Herein, 149 participants (PWH: 74; seronegative controls: 75) between the ages of 29-76 years completed a perceptual feature matching task that probes cognitive flexibility during high-density magnetoencephalography (MEG). Neural responses were decomposed into the time-frequency domain and significant oscillatory responses in the theta (4-8 Hz), alpha (10-16 Hz), and gamma (74-98 Hz) spectral windows were imaged using a beamforming approach. Whole-brain voxel-wise comparisons were then conducted on these dynamic functional maps to identify HIV-related differences in the neural oscillatory dynamics supporting cognitive flexibility. Our findings indicated group differences in alpha oscillatory activity in the cingulo-opercular cortices, and differences in gamma activity were found in the cerebellum. Across all participants, alpha and gamma activity in these regions were associated with performance on the cognitive flexibility task. Further, PWH who had been treated with antiretroviral therapy for a longer duration and those with higher current CD4 counts had alpha responses that more closely resembled those of seronegative controls, suggesting that optimal clinical management of HIV infection is associated with preserved neural dynamics supporting cognitive flexibility.

Levetiracetam Prevents Neurophysiological Changes and Preserves Cognitive Function in the Human Immunodeficiency Virus (HIV)-1 Transactivator of Transcription Transgenic Mouse Model of HIV-Associated Neurocognitive Disorder

Human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) affects nearly half of the 39 million people living with HIV. HAND symptoms range from subclinical cognitive impairment to dementia; the mechanisms that underlie HAND remain unclear and there is no treatment. The HIV protein transactivator of transcription (TAT) is thought to contribute to HAND because it persists in the central nervous system and elicits neurotoxicity in animal models. Network hyperexcitability is associated with accelerated cognitive decline in neurodegenerative disorders. Here we show that the antiepileptic drug levetiracetam (LEV) attenuated aberrant excitatory synaptic transmission, protected synaptic plasticity, reduced seizure susceptibility, and preserved cognition in inducible TAT (iTAT) transgenic male mice. iTAT mice had an increased frequency of spontaneous excitatory postsynaptic currents in hippocampal slice recordings and impaired long-term potentiation, a form of synaptic plasticity that underlies learning and memory. Two-week administration of LEV by osmotic minipump prevented both impairments. Kainic acid administered to iTAT mice induced a higher maximum behavioral seizure score, longer seizure duration, and shorter latency to first seizure, consistent with a lower seizure threshold. LEV treatment prevented these in vivo signs of hyperexcitability. Lastly, in the Barnes maze, iTAT mice required more time to reach the goal, committed more errors, and received lower cognitive scores relative to iTAT mice treated with LEV. Thus, TAT expression drives functional deficits, suggesting a causative role in HAND. As LEV not only prevented aberrant synaptic activity in iTAT mice but also prevented cognitive dysfunction, it may provide a promising pharmacological approach to the treatment of HAND. SIGNIFICANCE STATEMENT: Approximately half of people living with human immunodeficiency virus (HIV) also suffer from HIV-associated neurocognitive disorder (HAND), for which there is no treatment. The HIV protein transactivator of transcription (TAT) causes toxicity that is thought to contribute to HAND. Here, the antiepileptic drug levetiracetam (LEV) prevented synaptic and cognitive impairments in a TAT-expressing mouse. LEV is widely used to treat seizures and is well-tolerated in humans, including those with HIV. This study supports further investigation of LEV-mediated neuroprotection in HAND.

Awareness, treatment, and control of hypertension among women at risk or living with HIV in the US South

OBJECTIVES

Timely control of hypertension is vital to prevent comorbidities. We evaluated the association of race/ethnicity and HIV infection with incident hypertension outcomes, including awareness, treatment, and control.

DESIGN

We evaluated cisgender women living with HIV and sociodemographically matched women living without HIV recruited into four Southern sites of the Women's Interagency HIV Study (WIHS) (2013-2019).

METHODS

We calculated measurements of the time to four events or censoring: incident hypertension, hypertension awareness, hypertension treatment, and hypertension control. Hazard ratios for race/ethnicity and HIV status were calculated for each outcome using Cox proportional-hazards models adjusted for sociodemographic, behavioral, and clinical risk factors.

RESULTS

Among 712 women, 56% were hypertensive at baseline. Forty-five percentage of the remaining women who were normotensive at baseline developed incident hypertension during follow-up. Non-Hispanic white and Hispanic women had faster time to hypertension control compared with non-Hispanic black women ( P  = 0.01). In fully adjusted models, women living with HIV who were normotensive at baseline had faster time to treatment compared with normotensive women living without HIV ( P  = 0.04).

CONCLUSION

In our study of women in the US South, non-Hispanic black women became aware of their hypertension diagnosis more quickly than non-Hispanic white and Hispanic women but were slower to control their hypertension. Additionally, women living with HIV more quickly treated and controlled their hypertension compared with women living without HIV.

Age-associated dementia among older people aging with HIV in the United States: a modeling study

OBJECTIVE

Almost 400 000 people with HIV (PWH) in the United States are over age 55 years and at risk for age-associated dementias (AAD), including Alzheimer's disease and vascular contributions to cognitive impairment and dementia (VCID). We projected the cumulative incidence and mortality associated with AAD among PWH at least 60 years in the United States compared with the general population.

DESIGN/METHODS

Integrating the CEPAC and AgeD-Pol models, we simulated two cohorts of 60-year-old male and female individuals: PWH, and the general US population. We estimated AAD incidence and AAD-associated mortality rates. Projected outcomes included AAD cumulative incidence, life expectancy, and quality-adjusted life-years (QALYs). We performed sensitivity and scenario analyses on AAD-specific (e.g. incidence) and HIV-specific (e.g. disengagement from HIV care) parameters, as well as premature aging among PWH.

RESULTS

We projected that 22.1%/16.3% of 60-year-old male individuals/female individuals with HIV would develop AAD by 80 years compared with 15.9%/13.3% of male individuals/female individuals in the general population. Accounting for age-associated and dementia-associated quality of life, 60-year-old PWH would have a lower life expectancy (QALYs): 17.4 years (14.1 QALYs) and 16.8 years (13.4 QALYs) for male and female individuals, respectively, compared with the general population [male individuals, 21.7 years (18.4 QALYs); female individuals, 24.7 years (20.2 QALYs)]. AAD cumulative incidence was most sensitive to non-HIV-related mortality, engagement in HIV care, and AAD incidence rates.

CONCLUSION

Projected estimates of AAD-associated morbidity, mortality, and quality of life can inform decision-makers and health systems planning as the population of PWH ages. Improved AAD prevention, treatment, and supportive care planning are critical for people aging with HIV.

Cannabinoid receptor 1 positive allosteric modulator ZCZ011 shows differential effects on behavior and the endocannabinoid system in HIV-1 Tat transgenic female and male mice

The cannabinoid receptor type 1 (CB1R) is a promising therapeutic target for various neurodegenerative diseases, including HIV-1-associated neurocognitive disorder (HAND). However, the therapeutic potential of CB1R by direct activation is limited due to its psychoactive side effects. Therefore, research has focused on indirectly activating the CB1R by utilizing positive allosteric modulators (PAMs). Studies have shown that CB1R PAMs (ZCZ011 and GAT211) are effective in mouse models of Huntington's disease and neuropathic pain, and hence, we assess the therapeutic potential of ZCZ011 in a well-established mouse model of neuroHIV. The current study investigates the effect of chronic ZCZ011 treatment (14 days) on various behavioral paradigms and the endocannabinoid system in HIV-1 Tat transgenic female and male mice. Chronic ZCZ011 treatment (10 mg/kg) did not alter body mass, locomotor activity, or anxiety-like behavior regardless of sex or genotype. However, differential effects were noted in hot plate latency, motor coordination, and recognition memory in female mice only, with ZCZ011 treatment increasing hot plate latency and improving motor coordination and recognition memory. Only minor effects or no alterations were seen in the endocannabinoid system and related lipids except in the cerebellum, where the effect of ZCZ011 was more pronounced in female mice. Moreover, AEA and PEA levels in the cerebellum were positively correlated with improved motor coordination in female mice. In summary, these findings indicate that chronic ZCZ011 treatment has differential effects on antinociception, motor coordination, and memory, based on sex and HIV-1 Tat expression, making CB1R PAMs potential treatment options for HAND without the psychoactive side effects.

A helping HAND: therapeutic potential of MAGL inhibition against HIV-1-associated neuroinflammation

Background

Human immunodeficiency virus (HIV) affects nearly 40 million people globally, with roughly 80% of all people living with HIV receiving antiretroviral therapy. Antiretroviral treatment suppresses viral load in peripheral tissues but does not effectively penetrate the blood-brain barrier. Thus, viral reservoirs persist in the central nervous system and continue to produce low levels of inflammatory factors and early viral proteins, including the transactivator of transcription (Tat). HIV Tat is known to contribute to chronic neuroinflammation and synaptodendritic damage, which is associated with the development of cognitive, motor, and/or mood problems, collectively known as HIV-associated neurocognitive disorders (HAND). Cannabinoid anti-inflammatory effects are well documented, but therapeutic utility of cannabis remains limited due to its psychotropic effects, including alterations within brain regions encoding reward processing and motivation, such as the nucleus accumbens. Alternatively, inhibiting monoacylglycerol lipase (MAGL) has demonstrated therapeutic potential through interactions with the endocannabinoid system.

Methods

The present study utilized a reward-related operant behavioral task to quantify motivated behavior in female Tat transgenic mice treated with vehicle or MAGL inhibitor MJN110 (1 mg/kg). Brain tissue was collected to assess dendritic injury and neuroinflammatory profiles, including dendritic microtubule-associated protein (MAP2ab) intensity, microglia density, microglia morphology, astrocyte density, astrocytic interleukin-1ß (IL-1ß) colocalization, and various lipid mediators.

Results

No significant behavioral differences were observed; however, MJN110 protected against Tat-induced dendritic injury by significantly upregulating MAP2ab intensity in the nucleus accumbens and in the infralimbic cortex of Tat(+) mice. No or only minor effects were noted for Iba-1+ microglia density and/or microglia morphology. Further, Tat increased GFAP+ astrocyte density in the infralimbic cortex and GFAP+ astrocytic IL-1ß colocalization in the nucleus accumbens, with MJN110 significantly reducing these measures in Tat(+) subjects. Lastly, selected HETE-related inflammatory lipid mediators in the striatum were downregulated by chronic MJN110 treatment.

Conclusions

These findings demonstrate anti-inflammatory and neuroprotective properties of MJN110 without cannabimimetic behavioral effects and suggest a promising alternative to cannabis for managing neuroinflammation.

CNS Viral Infections-What to Consider for Improving Drug Treatment: A Plea for Using Mathematical Modeling Approaches

Neurotropic viruses may cause meningitis, myelitis, encephalitis, or meningoencephalitis. These inflammatory conditions of the central nervous system (CNS) may have serious and devastating consequences if not treated adequately. In this review, we first summarize how neurotropic viruses can enter the CNS by (1) crossing the blood-brain barrier or blood-cerebrospinal fluid barrier; (2) invading the nose via the olfactory route; or (3) invading the peripheral nervous system. Neurotropic viruses may then enter the intracellular space of brain cells via endocytosis and/or membrane fusion. Antiviral drugs are currently used for different viral CNS infections, even though their use and dosing regimens within the CNS, with the exception of acyclovir, are minimally supported by clinical evidence. We therefore provide considerations to optimize drug treatment(s) for these neurotropic viruses. Antiviral drugs should cross the blood-brain barrier/blood cerebrospinal fluid barrier and pass the brain cellular membrane to inhibit these viruses inside the brain cells. Some antiviral drugs may also require intracellular conversion into their active metabolite(s). This illustrates the need to better understand these mechanisms because these processes dictate drug exposure within the CNS that ultimately determine the success of antiviral drugs for CNS infections. Finally, we discuss mathematical model-based approaches for optimizing antiviral treatments. Thereby emphasizing the potential of CNS physiologically based pharmacokinetic models because direct measurement of brain intracellular exposure in living humans faces ethical restrictions. Existing physiologically based pharmacokinetic models combined with in vitro pharmacokinetic/pharmacodynamic information can be used to predict drug exposure and evaluate efficacy of antiviral drugs within the CNS, to ultimately optimize the treatments of CNS viral infections.

Cognitive impairment and neurocognitive profiles among people living with HIV and HIV-negative individuals older over 50 years: a comparison of IHDS, MMSE and MoCA

We aimed to examine the l differences in the assessment of neurocognitive impairment (NCI) using cognitive screening tools between PLWH and HIV-negative individuals and further compare the neurocognitive profiles between the two groups. This was baseline evaluation of Pudong HIV Aging Cohort, including 465 people living with HIV (PLWH) and 465 HIV-negative individuals aged over 50 years matched by age (± 3 years), sex and education. NCI was assessed using the Chinese version of Mini-mental State Examination (MMSE), the International HIV Dementia Scale (IHDS) and Beijing version of Montreal Cognitive Assessment (MoCA). In total, 258 (55.5%), 91 (19.6%), 273 (58.7%) of PLWH were classified as having NCI by the IHDS, MMSE and MoCA, compared to 90 (19.4%), 25 (5.4%), 135 (29.0%) of HIV-negative individuals, respectively (p < 0.05); such associations remained significant in multivariable analysis. PLWH showed a larger overlap of NCI detected by IHDS, MMSE, and MoCA. IHDS and MoCA detected almost all of the NCI detected by MMSE. IHDS-motor and psychomotor speeds and MoCA-executive function showed the greatest disparities between two groups. In multivariable analysis, older age and more depressive symptoms were positively associated with NCI regardless of the screening tools or HIV serostatus. PLWH over 50 years old display a higher prevalence of NCI and distinct neurocognitive profiles compared to HIV-negative individuals, despite viral suppression. Given the more considerable overlap in NCI classification in PLWH, it is advisable to choose one screening tool such as IHDS or MoCA to identify those potentially having NCI and then refer to more comprehensive neuropsychological assessment.

Effects of acute cannabidiol on behavior and the endocannabinoid system in HIV-1 Tat transgenic female and male mice

Background

Some evidence suggests that cannabidiol (CBD) has potential to help alleviate HIV symptoms due to its antioxidant and anti-inflammatory properties. Here we examined acute CBD effects on various behaviors and the endocannabinoid system in HIV Tat transgenic mice.

Methods

Tat transgenic mice (female/male) were injected with CBD (3, 10, 30 mg/kg) and assessed for antinociception, activity, coordination, anxiety-like behavior, and recognition memory. Brains were taken to quantify endocannabinoids, cannabinoid receptors, and cannabinoid catabolic enzymes. Additionally, CBD and metabolite 7-hydroxy-CBD were quantified in the plasma and cortex.

Results

Tat decreased supraspinal-related nociception and locomotion. CBD and sex had little to no effects on any of the behavioral measures. For the endocannabinoid system male sex was associated with elevated concentration of the proinflammatory metabolite arachidonic acid in various CNS regions, including the cerebellum that also showed higher FAAH expression levels for Tat(+) males. GPR55 expression levels in the striatum and cerebellum were higher for females compared to males. CBD metabolism was altered by sex and Tat expression.

Conclusion

Findings indicate that acute CBD effects are not altered by HIV Tat, and acute CBD has no to minimal effects on behavior and the endocannabinoid system.

Acute Effects of Monoacylglycerol Lipase Inhibitor ABX1431 on Neuronal Hyperexcitability, Nociception, Locomotion, and the Endocannabinoid System in HIV-1 Tat Male Mice

Background: Evidence suggests that monoacylglycerol lipase (MAGL) inhibitors can potentially treat HIV symptoms by increasing the concentration of 2-arachidonoylglycerol (2-AG). We examined a selective MAGL inhibitor ABX1431 in the context of neuroHIV. Methods: To assess the effects of ABX1431, we conducted in vitro and in vivo studies. In vitro calcium imaging on frontal cortex neuronal cultures was performed to evaluate the role of ABX1431 (10, 30, 100 nM) on transactivator of transcription (Tat)-induced neuronal hyperexcitability. Following in vitro experiments, in vivo experiments were performed using Tat transgenic male mice. Mice were treated with 4 mg/kg ABX1431 and assessed for antinociception using tail-flick and hot plate assays followed by locomotor activity. After the behavioral experiments, their brains were harvested to quantify endocannabinoids (eCB) and related lipids through mass spectrometry, and cannabinoid type-1 and -2 receptors (CB1R and CB2R) were quantified through western blot. Results: In vitro studies revealed that adding Tat directly to the neuronal cultures significantly increased intracellular calcium concentration, which ABX1431 completely reversed at all concentrations. Preincubating the cultures with CB1R and CB2R antagonists showed that ABX1431 exhibited its effects partially through CB1R. In vivo studies demonstrated that acute ABX1431 increased overall total distance traveled and speed of mice regardless of their genotype. Mass spectrometry and western blot analyses revealed differential effects on the eCB system based on Tat expression. The 2-AG levels were significantly upregulated following ABX1431 treatment in the striatum and spinal cord. Arachidonic acid (AA) was also upregulated in the striatum of vehicle-treated Tat(+) mice. No changes were noted in CB1R expression levels; however, CB2R levels were increased in ABX1431-treated Tat(-) mice only. Conclusion: Findings indicate that ABX1431 has potential neuroprotective effects in vitro partially mediated through CB1R. Acute treatment of ABX1431 in vivo shows antinociceptive effects, and seems to alter locomotor activity, with upregulating 2-AG levels in the striatum and spinal cord.

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).

Latent Profile Analysis of Cognitive Performance and Depressive Symptoms Among People with HIV

Depression and cognitive impairment are prevalent conditions among people with HIV (PWH), likely attributable to shared causes and common risk factors. Identifying subtypes of PWH with similar patterns of neurocognitive impairment (NCI) and depressive symptoms may inform development of patient-centered interventions that target-specific profiles. This study aimed to (1) classify PWH based on patterns of domain-specific NCI and depression; and (2) determine the relationship between latent class membership and pertinent clinical characteristics. PWH (N = 580, 86.2% male, 57.1% non-Hispanic White, 69.2% unemployed) completed a comprehensive neuropsychological test battery assessing global and domain-specific cognition. Domain-specific NCI was classified as deficit score >0.5. Participants completed the Beck Depression Inventory-II (BDI-II), and domain-specific BDI-II scores reflecting cognitive, affective, and somatic symptoms were computed. Latent profile analysis (LPA) was used to determine latent subgroups of NCI and depression. The optimal LPA solution consisted of five classes: minimal NCI and minimal depression (Class 1), amnestic and minimal depression (Class 2), severe multi-domain NCI and moderate depression (somatic and affective; Class 3), mild NCI and mild depression (Class 4), and moderate multi-domain NCI and severe depression (Class 5). Despite similar levels of functional impairment, Class 5 had a significant psychiatric profile, whereas Class 3 had a complex medical profile (i.e., higher frailty index, higher medications, greater proportion of AIDS diagnosis). In contrast, Class 1 had the lowest medication use and frailty index, with similar HIV disease characteristics to Classes 3 and 5. Our results suggest there are multiple pathways to cognitive and functional impairment among PWH with co-occurring depression and cognitive impairment, and these groups may respond differently to interventions. Of note, our sample was majority non-Hispanic White and male, which is nonrepresentative of the US population of PWH. Future interventions should consider a more integrated, person-centered approach that addresses cognitive and emotional health to optimize health outcomes in PWH.

Effects of acute Δ9-tetrahydrocannabinol on behavior and the endocannabinoid system in HIV-1 Tat transgenic female and male mice

Cannabis use is highly prevalent especially among people living with HIV (PLWH). Activation of the anti-inflammatory and neuroprotective endocannabinoid system by phytocannabinoids, i.e. Δ9-tetrahydrocannabinol (THC), has been proposed to reduce HIV symptoms. However, THC's effects on HIV-related memory deficits are unclear. Using HIV-1 Tat transgenic mice, the current study investigates acute THC effects on various behavioral outcomes and the endocannabinoid system. For the rodent tetrad model, THC doses (1, 3, 10 mg/kg) induced known antinociceptive effects, with Tat induction increasing antinociceptive THC effects at 3 and 10 mg/kg doses. Only minor or no effects were noted for acute THC on body temperature, locomotor activity, and coordination. Increased anxiety-like behavior was found for females compared to males, but acute THC had no effect on anxiety. Object recognition memory was diminished by acute THC in Tat(-) females but not Tat(+) females, without affecting males. The endocannabinoid system and related lipids were not affected by acute THC, except for THC-induced decreases in CB1R protein expression levels in the spinal cord of Tat(-) mice. Female sex and Tat induction was associated with elevated 2-AG, AEA, AA, CB1R, CB2R, FAAH and/or MAGL expression in various brain regions. Further, AEA levels in the prefrontal cortex of Tat(+) females were negatively associated with object recognition memory. Overall, findings indicate that acute THC exerts differential effects on antinociception and memory, dependent on sex and HIV Tat expression, potentially in relation to an altered endocannabinoid system, which may be of relevance in view of potential cannabis-based treatment options for PLWH.

The relationship between synaptodendritic neuropathology and HIV-associated neurocognitive disorders is moderated by cognitive reserve

We examined whether cognitive reserve moderated the relationship between neurodegeneration and cognition in 67 postmortem persons with HIV (PWH) who were cognitively assessed within 1 year of death. Cognitive reserve was measured via the Wide Range Achievement Test-4 reading subtest (WRAT4). Synaptodendritic neurodegeneration was based on densities of synaptophysin and microtubule-associated protein 2 immunohistochemical reactivity in frontal cortex, and categorized as minimal, moderate, or severe (tertile-split). T-Scores from 15 cognitive tests were averaged into a global cognitive T-score. Among those with low cognitive reserve (based on WRAT4 median split), the moderate neurodegeneration group showed cognition that was poorer than the minimal neurodegeneration group and comparable to the severe neurodegeneration group. Among those with high cognitive reserve, the moderate neurodegeneration group showed cognition comparable to the minimal neurodegeneration group and better than the severe neurodegeneration group. High cognitive reserve may buffer against cognitive impairment among PWH with moderate, but not severe, neurodegeneration.

Alzheimer's disease as a viral disease: Revisiting the infectious hypothesis

Alzheimer's disease (AD) represents the most frequent type of dementia in elderly people. Two major forms of the disease exist: sporadic - the causes of which have not yet been fully understood - and familial - inherited within families from generation to generation, with a clear autosomal dominant transmission of mutations in Presenilin 1 (PSEN1), 2 (PSEN2) or Amyloid Precursors Protein (APP) genes. The main hallmark of AD consists of extracellular deposits of amyloid-beta (Aβ) peptide and intracellular deposits of the hyperphosphorylated form of the tau protein. An ever-growing body of research supports the viral infectious hypothesis of sporadic forms of AD. In particular, it has been shown that several herpes viruses (i.e., HHV-1, HHV-2, HHV-3 or varicella zoster virus, HHV-4 or Epstein Barr virus, HHV-5 or cytomegalovirus, HHV-6A and B, HHV-7), flaviviruses (i.e., Zika virus, Dengue fever virus, Japanese encephalitis virus) as well as Human Immunodeficiency Virus (HIV), hepatitis viruses (HAV, HBV, HCV, HDV, HEV), SARS-CoV2, Ljungan virus (LV), Influenza A virus and Borna disease virus, could increase the risk of AD. Here, we summarized and discussed these results. Based on these findings, significant issues for future studies are also put forward.

Neurological, Behavioral, and Pathophysiological Characterization of the Co-Occurrence of Substance Use and HIV: A Narrative Review

Combined antiretroviral therapy (cART) has greatly reduced the severity of HIV-associated neurocognitive disorders in people living with HIV (PLWH); however, PLWH are more likely than the general population to use drugs and suffer from substance use disorders (SUDs) and to exhibit risky behaviors that promote HIV transmission and other infections. Dopamine-boosting psychostimulants such as cocaine and methamphetamine are some of the most widely used substances among PLWH. Chronic use of these substances disrupts brain function, structure, and cognition. PLWH with SUD have poor health outcomes driven by complex interactions between biological, neurocognitive, and social factors. Here we review the effects of comorbid HIV and psychostimulant use disorders by discussing the distinct and common effects of HIV and chronic cocaine and methamphetamine use on behavioral and neurological impairments using evidence from rodent models of HIV-associated neurocognitive impairments (Tat or gp120 protein expression) and clinical studies. We also provide a biopsychosocial perspective by discussing behavioral impairment in differentially impacted social groups and proposing interventions at both patient and population levels.

Sex differences in cognitive function among people with HIV-1 clade C infection in Northern India

Human immunodeficiency virus-1 (HIV-1) clade C is the most prevalent form of HIV-1 comprising nearly 46% of global infections and is the dominant subtype in India. Despite its predominance, the impact of HIV-1 clade C infection on cognitive function has been understudied in comparison with other subtypes, notably clade B, which is primarily found in Europe and North America. Few studies have assessed cognitive impairment in antiretroviral therapy (ART) naïve men and women with HIV-1 clade C infection. In this study conducted in Northern India, differences in neuropsychological functioning were compared between 109 participants (70 men, 39 women) with untreated HIV-1 clade C infection and 110 demographically matched healthy controls (74 men, 36 women). A comprehensive neuropsychological battery was used to examine depression, self-assessment of functioning, and cognitive performance in six domains of functioning. Group differences were assessed by HIV-1 status and sex, controlling for age and education. Results indicated that cognitive deficits were substantially greater among male participants with HIV-1 clade C compared to male controls in all domains of cognitive functioning; in contrast, women with HIV-1 clade C had only minor deficits compared to healthy female participants. In addition, a larger proportion of men with HIV-1 clade C exhibited high levels of depression than women with HIV-1 clade C. These findings suggest that untreated HIV-1 clade C infection in men can have debilitating effects on neuropsychological function and depression, and stress the importance of facilitating rapid access to treatment to reduce the impact of HIV-1 infection.

Alzheimer's Disease Pathology in Middle Aged and Older People with HIV: Comparisons with Non-HIV Controls on a Healthy Aging and Alzheimer's Disease Trajectory and Relationships with Cognitive Function

We determined the prevalence of Alzheimer's disease (AD) pathological hallmarks, amyloid-β and phosphorylated-Tau, in autopsied brains of 49 people with HIV (PWH) (ages: 50-68; mean age = 57.0) from the National NeuroAIDS Tissue Consortium and in a comparative cohort of 55 people without HIV (PWoH) from the UC San Diego Alzheimer's Disease Research Center (17 controls, 14 mild cognitive impairment, 24 AD; ages: 70-102, mean age = 88.7). We examined how AD pathology relates to domain-specific cognitive functions in PWH overall and in sex-stratified samples. Amyloid-β and phosphorylated-Tau positivity (presence of pathology of any type/density) was determined via immunohistochemistry in AD-sensitive brain regions. Among PWH, amyloid-β positivity ranged from 19% (hippocampus) to 41% (frontal neocortex), and phosphorylated-Tau positivity ranged from 47% (entorhinal cortex) to 73% (transentorhinal cortex). Generally, AD pathology was significantly less prevalent, and less severe when present, in PWH versus PWoH regardless of cognitive status. Among PWH, positivity for AD pathology related most consistently to memory-related domains. Positivity for p-Tau pathology related to memory-related domains in women with HIV only, although the sample size of women with HIV was small (n = 10). Results indicate that AD pathology is present in a sizable portion of middle aged and older PWH, although not to the extent in older PWoH. Studies with better age-matched PWoH are needed to examine the effect of HIV status on AD pathology.

Cocaine Use May Moderate the Associations of HIV and Female Sex with Neurocognitive Impairment in a Predominantly African American Population Disproportionately Impacted by HIV and Substance Use

HIV-associated neurocognitive disorders (HAND) remain a major challenge for people with HIV in the antiretroviral therapy era. Cocaine use may trigger/exacerbate HAND among African American (AA) adults, especially women. Between 2018 and 2019, 922 adults, predominantly AAs, with/without HIV and with/without cocaine use in Baltimore, Maryland, were enrolled in a study investigating the association of HIV and cocaine use with neurocognitive impairment (NCI). Neurocognitive performance was assessed with the NIH Toolbox Cognition Battery (NIHTB-CB). NCI was considered to be present if the fully adjusted standard score for at least two cognitive domains was 1.0 standard deviation below the mean. Although the overall analysis showed HIV and female sex were associated with NCI, the associations were dependent on cocaine use. Neither HIV [adj prevalence ratio (PR): 1.12, confidence interval (95% CI): 0.77-1.64] nor female sex (adj PR: 1.07, 95% CI: 0.71-1.61) was associated with NCI among cocaine nonusers, while both HIV (adj PR: 1.39, 95% CI: 1.06-1.81) and female sex (adj PR: 1.53, 95% CI: 1.18-1.98) were associated with NCI in cocaine users. HIV was associated with two NIHTB-CB measures overall. In addition, HIV was associated with a lower dimensional change card sort score (an executive function measure) in cocaine users and not in nonusers. Cognitive performance was poorer in female than in male cocaine users. The adverse effect of HIV on cognitive performance predominantly affected cocaine users. However, cocaine use may moderate the impact of HIV and female sex on cognitive performance, highlighting the importance of reducing cocaine use in NCI prevention among the AA population.

The comorbidity of depression and neurocognitive disorder in persons with HIV infection: call for investigation and treatment

Depression and neurocognitive disorder continue to be the major neuropsychiatric disorders affecting persons with HIV (PWH). The prevalence of major depressive disorder is two to fourfold higher among PWH than the general population (∼6.7%). Prevalence estimates of neurocognitive disorder among PWH range from 25 to over 47% - depending upon the definition used (which is currently evolving), the size of the test battery employed, and the demographic and HIV disease characteristics of the participants included, such as age range and sex distribution. Both major depressive disorder and neurocognitive disorder also result in substantial morbidity and premature mortality. However, though anticipated to be relatively common, the comorbidity of these two disorders in PWH has not been formally studied. This is partly due to the clinical overlap of the neurocognitive symptoms of these two disorders. Both also share neurobehavioral aspects - particularly apathy - as well as an increased risk for non-adherence to antiretroviral therapy. Shared pathophysiological mechanisms potentially explain these intersecting phenotypes, including neuroinflammatory, vascular, and microbiomic, as well as neuroendocrine/neurotransmitter dynamic mechanisms. Treatment of either disorder affects the other with respect to symptom reduction as well as medication toxicity. We present a unified model for the comorbidity based upon deficits in dopaminergic transmission that occur in both major depressive disorder and HIV-associated neurocognitive disorder. Specific treatments for the comorbidity that decrease neuroinflammation and/or restore associated deficits in dopaminergic transmission may be indicated and merit study.

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.

Neurology of Systemic Disease

Sex differences exist within the neurologic complications of systemic disease. To promote new avenues for prevention and develop novel therapeutics, we highlight the role of sex in differential outcomes to infectious disease and cardiac arrest and educate the reader in paraneoplastic presentations that may herald underlying malignancies in women.

Sex-Specific Neurocognitive Impairment

This article explores sex-specific neurocognitive impairment. It first defines relevant terms such as gender and sex. Next, it describes the nature of the problem including under-representation of women and other gender and sexual minorities in neuroscience research, including cognitive studies. A biopsychosocial framework is employed to account for structural and social determinants of health in sex/gender-specific neurocognitive impairment. Issues in assessment including the use of gender/sex-specific normative data are also discussed. Lastly, the article covers the current state of research as it relates to sex/gender-specific neurocognitive impairment across a range of medical conditions including neurodegenerative diseases and coronavirus disease-2019.

The global burden of cognitive impairment in people with HIV

OBJECTIVE

While life expectancies of people with HIV (PWH) have increased through the successes of antiretroviral treatment, cognitive impairment remains a pressing concern. Prevalence estimates vary worldwide as different definitions for cognitive impairment are used and resource availability differs across geographical settings. We aim to explore this heterogeneity and estimate the global cognitive impairment burden in PWH.

DESIGN

Systematic literature review and meta-analysis.

METHODS

We searched PubMed, Embase, SCOPUS, and Web of Science for studies reporting on cognitive impairment prevalence in PWH. Nine factors were investigated for their potential association with the prevalence using a univariate meta-analysis and a meta-regression: assessment method, geographical region, country income, exclusion criteria, study quality, age, sex, publication year, and sample size.

RESULTS

The literature search identified 8539 records, of which 225 were included. The adjusted prevalence was significantly lower in males than females. Across 44 countries, 12 assessment methods were used; the HIV-associated neurocognitive disorder/Frascati criteria, known for high false-positive rates, was employed in 44.4% of studies. The pooled cognitive impairment prevalence estimate in PWH, including asymptomatic cases, was 39.6% (95% confidence interval: 37.2-42.1%; range: 7-87%). The meta-regression explained 13.3% of between-study variation, with substantial residual heterogeneity ( I2  = 97.7%).

CONCLUSION

Lack of data from more than 70% of the world's countries, cohorts being unselected for symptoms in most research studies, and limitations of the HIV-associated neurocognitive disorder/Frascati criteria restrict the ability to accurately determine the global burden of cognitive impairment in PWH. More studies in low-resource settings and a standardized approach to assessing cognitive impairment, bridging research and clinical realms, are needed.

Sex Differences in the Cognitive Performance of a South African Cohort of People With HIV and Comorbid Major Depressive Disorder

Women with HIV (WWH) may be more vulnerable to cognitive impairment than men with HIV (MWH), which may be explained by the direct effects of HIV or by sociodemographic and psychiatric characteristics. We recruited 105 people with HIV (PWH; 76 women) with incomplete antiretroviral therapy adherence, comorbid major depressive disorder, and socioeconomically disadvantaged backgrounds. Participants completed neuropsychological testing and measures gathering sociodemographic, medical, and psychiatric information. We compared WWH and MWH cognitive performance using unadjusted and adjusted regressions, and within each respective group, we explored predictors of cognitive performance. Results showed no significant between-sex differences in cognitive performance, both globally and within domains. Fewer years of education (β = 0.94), illiteracy (β = 4.55), and greater food insecurity (β = -0.28) predicted lower cognitive performance in WWH but not MWH. We conclude that sex differences in PWH are likely due to sample characteristics representing broader inequalities, rather than true biological differences.

Glucocorticoid Receptor Function and Cognitive Performance in Women With HIV

OBJECTIVE

Alterations in glucocorticoid receptor (GCR) function may be a risk factor for cognitive complications among older people with human immunodeficiency virus (HIV). We evaluated whether HIV serostatus and age modify the GCR function-cognition association among women.

METHODS

Eighty women with HIV ( n = 40, <40 years of age [younger]; n = 40, >50 years of age [older]) and 80 HIV-uninfected women ( n = 40 older, n = 40 younger) enrolled in the Women's Interagency HIV Study completed a comprehensive neuropsychological test battery. Peripheral blood mononuclear cells collected concurrent with neuropsychological testing were assessed for GCR function. Multivariable linear regression analyses were conducted to examine whether a) HIV serostatus and age were associated with GCR function, and b) GCR function-cognition associations are moderated by HIV serostatus and age adjusting for relevant covariates.

RESULTS

Among older women, higher baseline FKBP5 expression level was associated with lower attention/working memory performance among women with HIV ( B = 6.4, standard error = 1.7, p = .0003) but not in women without HIV infection ( B = -1.7, standard error = 1.9, p = .37). There were no significant HIV serostatus by age interactions on dexamethasone (DEX)-stimulated expression of the genes regulated by the GCR or lipopolysaccharide-stimulated tumor necrosis factor α levels (with or without DEX stimulation; p values > .13). HIV serostatus was associated with GC target genes PER1 ( p = .006) and DUSP1 ( p = .02), but not TSC22D3 ( p = .32), after DEX stimulation.

CONCLUSIONS

Collectively, these data suggest that HIV serostatus and age may modify the influence of the GCR, such that the receptor is likely engaged to a similar extent, but the downstream influence of the receptor is altered, potentially through epigenetic modification of target genes.

Class-Based Antiretroviral Exposure and Cognition Among Women Living with HIV

Neurologic complications of the human immunodeficiency virus (HIV) are common in treated individuals, and toxicity of certain antiretroviral therapies (ART) may contribute to cognitive impairment. We investigated exposures to specific ART and cognition among women living with HIV (WLWH). Virologically suppressed (viral load <200 copies/mL during at least two semi-annual visits) WLWH and age/race matched HIV-seronegative controls enrolled in the Women's Interagency HIV Study who completed at least two biennial cognitive assessments were included. Analysis of WLWH was restricted to those with exposure to the drug class of interest and a nucleoside reverse transcriptase inhibitor (NRTI) backbone. Generalized estimating equations were used to evaluate repeated measures of cognition over time in association with ART class exposure. Among 1,242 eligible WLWH, 20% (n = 247) had isolated drug exposure to non-nucleoside reverse transcriptase inhibitors (NNRTI), 18% (n = 219) to protease inhibitors (PIs), and 6% (n = 79) to integrase inhibitors with a NRTI backbone. Cognitive assessments were performed at a median of 3 biennial visits {IQR 2-4 visits}. At the index assessment, 21% of WLWH demonstrated global cognitive impairment versus 29% at their last cognitive assessment. In multivariable analyses adjusted for hypertension, depression, diabetes mellitus, history of AIDS-defining illness, alcohol use, number of medications, and time on ART, WLWH exposed to NNRTIs demonstrated verbal learning improvements (mean T-score change 1.3, p = .020) compared to other treated women. Compared to HIV-seronegative women, WLWH exposed to PIs had worse verbal learning (mean T-score difference -2.62, p = .002) and verbal memory performance (mean T-score difference -1.74, p = .032) at baseline. Compared to HIV-seronegative women, WLWH exposed to PIs had improvements in verbal learning (mean T-score slope difference 0.36, p = .025) and verbal memory (mean T-score slope difference 0.32, p = .042). The index T-score and slope of change in the T-score were similar among other treated groups and the HIV-seronegative group. We noted emerging trends in cognition in WLWH exposed to specific drug classes. Ongoing study of this relatively young group is important to characterize long-term cognitive outcomes and effect of antiretrovirals as treatment guidelines evolve.

Difference in the neurocognitive functions of WLWH and MLWH in an Italian cohort of people living with HIV

Based on the available literature, women living with HIV (WLWH) seem to show greater cognitive and emotional disadvantages than men living with HIV (MLWH). Our aim was to compare the cognitive performance of MLWH and WLWH in an Italian cohort of People Living With HIV (PLWH) and to analyse factors potentially contributing to sex differences in cognitive function. We ran a retrospective, cross-sectional analysis of a monocentric dataset of PLWH who were administered a standardized neuropsychological test battery (SNB) during routine clinical care. We enrolled 161 Italian PLWH who are on combined antiretroviral therapy (cART): 114 (70.8%) MLWH and 47 (29.2%) WLWH.

Global cognitive performance (composite z score) (GCP) was significantly higher in MLWH than WLWH [mean 0.19 (SD 0.85) vs − 0.13 (SD 0.96); p = 0.039]. Moreover, WLWH obtained significantly higher scores on the Zung Depression Scale than MLWH [mean 41.8 (SD 10.9) vs 36.7 (SD 9.2); p = 0.003]. However, there was no statistically significant direct effect between male sex and better GCP (p = 0.692) in the context of a mediation model. On the contrary, the associations between male sex and better GCP were mediated by higher level of education (a*b =  + 0.15, Bootstrap CI95 = 0.05 and 0.27) and a lower Zung depression score (a*b =  + 0.10, Bootstrap CI95 = 0.02 and 0.21).

In conclusion, the global cognitive performance of WLWH is lower than that of MLWH. However, other demographic and clinical factors besides sex might help explain differences in their neurocognitive functions and make it possible for us to monitor them and identify those patients most in need.

The impacts of HIV infection, age, and education on functional brain networks in adults with HIV

HIV-associated neurocognitive disorders (HAND) remain highly prevalent in people with HIV (PWH). Studies suggested that certain sociodemographic factors are associated with the risk of HAND in PWH. Here we investigated the impact of HIV infection and demographics on functional brain networks. One run of 8.5 min resting state functional MRI (fMRI) data was collected from 101 PWH (41-70 years old) and 40 demographically comparable controls. Functional connectivity (FC) was calculated using average wavelet coherence. The impact of demographic factors on FCs was investigated using canonical correlation analysis (CCA). Wavelet coherence analysis revealed a reduced within-network connectivity in the dorsal somatomotor network (dSMN), along with a reduced between-network connectivity between dSMN and medial temporal lobe (MTL) in PWH (compared to controls). Across all participants, CCA revealed that older age and HIV infection had negative impacts on network connectivity measures (mainly reduced within- and between-network FCs), whereas education had an opposite effect. In addition, being female at birth or a member of a minority ethnic/racial group was also associated with network disruptions. Our data suggested that advanced age and HIV infection are risk factors for functional brain network disruptions, whereas higher educational attainment was linked to better preserved functional network connectivity.

Inhibitory Neurotransmission Is Sex-Dependently Affected by Tat Expression in Transgenic Mice and Suppressed by the Fatty Acid Amide Hydrolase Enzyme Inhibitor PF3845 via Cannabinoid Type-1 Receptor Mechanisms

(1) Background. The endocannabinoid (eCB) system, which regulates physiological and cognitive processes, presents a promising therapeutic target for treating HIV-associated neurocognitive disorders (HAND). Here we examine whether upregulating eCB tone has potential protective effects against HIV-1 Tat (a key HIV transactivator of transcription) protein-induced alterations in synaptic activity. (2) Methods. Whole-cell patch-clamp recordings were performed to assess inhibitory GABAergic neurotransmission in prefrontal cortex slices of Tat transgenic male and female mice, in the presence and absence of the fatty acid amide hydrolase (FAAH) enzyme inhibitor PF3845. Western blot and mass spectrometry analyses assessed alterations of cannabinoid receptor and enzyme protein expression as well as endogenous ligands, respectively, to determine the impact of Tat exposure on the eCB system. (3) Results. GABAergic activity was significantly altered upon Tat exposure based on sex, whereas the effectiveness of PF3845 to suppress GABAergic activity in Tat transgenic mice was not altered by Tat or sex and involved CB1R-related mechanisms that depended on calcium signaling. Additionally, our data indicated sex-dependent changes for AEA and related non-eCB lipids based on Tat induction. (4) Conclusion. Results highlight sex- and/or Tat-dependent alterations of GABAergic activity and eCB signaling in the prefrontal cortex of Tat transgenic mice and further increase our understanding about the role of FAAH inhibition in neuroHIV.

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.

Endolysosome Localization of ERα Is Involved in the Protective Effect of 17α-Estradiol against HIV-1 gp120-Induced Neuronal Injury

Neurotoxic HIV-1 viral proteins contribute to the development of HIV-associated neurocognitive disorder (HAND), the prevalence of which remains high (30-50%) with no effective treatment available. Estrogen is a known neuroprotective agent; however, the diverse mechanisms of estrogen action on the different types of estrogen receptors is not completely understood. In this study, we determined the extent to which and mechanisms by which 17α-estradiol (17αE2), a natural less-feminizing estrogen, offers neuroprotection against HIV-1 gp120-induced neuronal injury. Endolysosomes are important for neuronal function, and endolysosomal dysfunction contributes to HAND and other neurodegenerative disorders. In hippocampal neurons, estrogen receptor α (ERα) is localized to endolysosomes and 17αE2 acidifies endolysosomes. ERα knockdown or overexpressing an ERα mutant that is deficient in endolysosome localization prevents 17αE2-induced endolysosome acidification. Furthermore, 17αE2-induced increases in dendritic spine density depend on endolysosome localization of ERα. Pretreatment with 17αE2 protected against HIV-1 gp120-induced endolysosome deacidification and reductions in dendritic spines; such protective effects depended on endolysosome localization of ERα. In male HIV-1 transgenic rats, we show that 17αE2 treatment prevents the development of enlarged endolysosomes and reduction in dendritic spines. Our findings demonstrate a novel endolysosome-dependent pathway that governs the ERα-mediated neuroprotective actions of 17αE2, findings that might lead to the development of novel therapeutic strategies against HAND.SIGNIFICANCE STATEMENT Extranuclear presence of membrane-bound estrogen receptors (ERs) underlie the enhancing effect of estrogen on cognition and synaptic function. The estrogen receptor subtype ERα is present on endolysosomes and plays a critical role in the enhancing effects of 17αE2 on endolysosomes and dendritic spines. These findings provide novel insight into the neuroprotective actions of estrogen. Furthermore, 17αE2 protected against HIV-1 gp120-induced endolysosome dysfunction and reductions in dendritic spines, and these protective effects of 17αE2 were mediated via endolysosome localization of ERα. Such findings provide a rationale for developing 17αE2 as a therapeutic strategy against HIV-associated neurocognitive disorders.

Sex Differences in Non-AIDS Comorbidities Among People With Human Immunodeficiency Virus

Women are grossly underrepresented in human immunodeficiency virus (HIV) clinical and translational research. This is concerning given that people with HIV (PWH) are living longer, and thus accumulating aging-related non-AIDS comorbidities (NACMs); emerging evidence suggests that women are at higher risk of NACM development and progression compared with men. It is widely recognized that women vs men have greater immune activation in response to many viruses, including HIV-1; this likely influences sex-differential NACM development related to differences in HIV-associated chronic inflammation. Furthermore, many sociobehavioral factors that contribute to aging-related NACMs are known to differ by sex. The objectives of this review were to (1) synthesize sex-stratified data on 4 NACMs among PWH: bone disease, cardiovascular disease, metabolic dysfunction, and neurocognitive impairment; (2) evaluate the characteristics of key studies assessing sex differences in NACMs; and (3) introduce potential biological and psychosocial mechanisms contributing to emerging trends in sex-differential NACM risk and outcomes among PWH.

Cognitive Differences between Men and Women with HIV: A Systematic Review and Meta-Analysis

OBJECTIVE

Although many studies report that women with HIV (WWH) are more vulnerable to cognitive impairment than men with HIV (MWH), this trend is not described consistently in the literature. In this systematic review and meta-analysis, we investigated whether the weight of evidence supports the existence of a significant sex difference in cognitive functioning among people with HIV and, if so, whether specific domains are affected.

METHOD

A systematic literature search retrieved 4,062 unique articles published between January 2000 and June 2019. Eligibility criteria were that studies directly compared adult WWH and MWH using a neuropsychological test battery. After extensive screening, we included 11 studies in the systematic review (N = 3,333) and 6 in the meta-analysis (N = 2,852).

RESULTS

Six studies included in the systematic review found WWH performed significantly more poorly on measures of cognitive performance than MWH; the other five found no sex differences. Meta-analytic results indicated that WWH performed significantly more poorly than MWH in three cognitive domains (psychomotor coordination, visuospatial learning, and memory), but magnitudes of effect sizes were small (d = -.16, -.43, and - .30, respectively). Analyses detected no sex differences in global cognitive functioning and in the other cognitive domains.

CONCLUSIONS

Sex differences in cognitive performance are small, and sociodemographic and psychiatric characteristics of WWH and MWH differ between studies. Cognitive differences between WWH and MWH may be explained by sex-based variation in these characteristics, the impact of which seems to outweigh that of HIV-related clinical variables (e.g., CD4 count and viral load).

Gray matter volumes discriminate cognitively impaired and unimpaired people with HIV

BACKGROUND

Current diagnostic criteria of HIV-associated neurocognitive disorders (HAND) rely on neuropsychological assessments. The aim of this study was to evaluate if gray matter volumes (GMV) can distinguish people with HAND, neurocognitively unimpaired people with HIV (unimpaired PWH), and uninfected controls using linear discriminant analyses.

METHODS

A total of 231 participants, including 110 PWH and 121 uninfected controls, completed a neuropsychological assessment and an MRI protocol. Among PWH, HAND (n = 48) and unimpaired PWH (n = 62) designations were determined using the widely accepted Frascati criteria. We then assessed the extent to which GMV, corrected for intracranial volume, could accurately distinguish the three groups using linear discriminant analysis. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, area under the curve (AUC), and accuracy were computed for each model using the classification results based on GMV compared to the neuropsychological assessment.

RESULTS

The best performing model was comprised of bilaterally combined GMV and was stratified by sex. Among males, sensitivity was 85.2% (95% CI: 66.3%-95.8%), specificity was 97.0% (95% CI: 91.6%-99.4%), and the AUC was 0.91 (95% CI: 0.83-0.99). Among females, sensitivity was 100.0% (95% CI: 83.9%-100.0%), specificity was 98.8% (95% CI: 93.4%-100.0%), and the AUC was 0.99 (95% CI: 0.98-1.00).

CONCLUSIONS

GMV accurately discriminated HAND from unimpaired PWH and controls. Measures of GMV may be highly sensitive to HAND, and revisions to the Frascati criteria should consider including GMV in conjunction with a neuropsychological assessment to diagnose HAND.

The Intersection of Cognitive Ability and HIV: A Review of the State of the Nursing Science

ABSTRACT

Neurocognitive problems have been endemic to the HIV epidemic since its beginning. Four decades later, these problems persist, but currently, they are attributed to HIV-induced inflammation, the long-term effects of combination antiretroviral therapy, lifestyle (i.e., physical activity, drug use), psychiatric, and age-associated comorbidities (i.e., heart disease, hypertension). In many cases, persons living with HIV (PLWH) may develop cognitive problems as a function of accelerated or accentuated normal aging and lifestyle rather than HIV itself. Nonetheless, such cognitive impairments can interfere with HIV care, including medication adherence and attending clinic appointments. With more than half of PLWH 50 years and older, and 30%-50% of all PLWH meeting the criteria for HIV-associated neurocognitive disorder, those aging with HIV may be more vulnerable to developing cognitive problems. This state of the science article provides an overview of current issues and provides implications for practice, policy, and research to promote successful cognitive functioning in PLWH.

HIV and women in the USA: what we know and where to go from here

New diagnoses of HIV infection have decreased among women in the USA overall, but marked racial and geographical disparities persist. The federal government has announced an initiative that aims to decrease the number of new infections in the nation by 90% within the next 10 years. With this in mind, we highlight important recent developments concerning HIV epidemiology, comorbidities, treatment, and prevention among women in the USA. We conclude that, to end the US HIV epidemic, substantially greater inclusion of US women in clinical research will be required, as will better prevention and treatment efforts, with universal access to health care and other supportive services that enable women to exercise agency in their own HIV prevention and care. Ending the epidemic will also require eliminating the race, class, and gender inequities, as well as the discrimination and structural violence, that have promoted and maintained the distribution of HIV in the USA, and that will, if unchecked, continue to fuel the epidemic in the future.

Sex-specific associations between cerebrospinal fluid inflammatory marker levels and cognitive function in antiretroviral treated people living with HIV in rural Uganda

People with HIV (PWH) taking antiretroviral therapy (ART) have persistent cognitive impairment. The prevalence of cognitive impairment is higher in women with HIV (WWH) compared to men with HIV (MWH), possibly due to sex differences in immune function. Here we report sex differences in cerebrospinal fluid (CSF) immune markers in relation to cognitive performance. A subset of 83 PWH on ART (52% WWH; mean age = 37.6 years, SD = 7.9) from the Rakai community cohort study Cohort and Rakai Health Sciences Program supported clinics in rural Uganda completed a neuropsychological (NP) assessment and a lumbar puncture. CSF was used to measure 16 cytokines/chemokines. Individual NP test z-scores were generated based on local normative data. A series of least absolute shrinkage and selection operator (lasso) regressions examined associations between CSF inflammatory markers and NP outcomes. Overall, there were no sex differences in CSF inflammatory marker levels. However, MWH displayed more associations between inflammatory markers and cognitive performance than WWH. Among MWH, inflammatory markers were associated with a number of cognitive domains, including attention, processing speed, fluency, executive function, learning and memory. MIP-1β, INF-γ, GM-CSF, IL-7 and IL-12p70 were associated with multiple domains. Among WWH, few inflammatory markers were associated cognition. Degree of associations between CSF inflammatory biomarkers and cognitive performance varied by sex in this young, ART-treated, Ugandan cohort. Further investigation into sex-specific inflammatory mechanisms of cognitive impairment among PWH is warranted to inform sex-specific management strategies.

Neuroimaging and Cognitive Evidence for Combined HIV-Alcohol Effects on the Central Nervous System: A Review

Alcohol use disorder (AUD) among people living with HIV (PLWH) is a significant public health concern. Despite the advent of effective antiretroviral therapy, up to 50% of PLWH still experience worsened neurocognition, which comorbid AUD exacerbates. We report converging lines of neuroimaging and neuropsychological evidence linking comorbid HIV/AUD to dysfunction in brain regions linked to executive function, learning and memory, processing speed, and motor control, and consequently to impairment in daily life. The brain shrinkage, functional network alterations, and brain metabolite disruption seen in individuals with HIV/AUD have been attributed to several interacting pathways: viral proteins and EtOH are directly neurotoxic and exacerbate each other's neurotoxic effects; EtOH reduces antiretroviral adherence and increases viral replication; AUD and HIV both increase gut microbial translocation, promoting systemic inflammation and HIV transport into the brain by immune cells; and HIV may compound alcohol's damaging effects on the liver, further increasing inflammation. We additionally review the neurocognitive effects of aging, Hepatitis C coinfection, obesity, and cardiovascular disease, tobacco use, and nutritional deficiencies, all of which have been shown to compound cognitive changes in HIV, AUD, and in their comorbidity. Finally, we examine emerging questions in HIV/AUD research, including genetic and cognitive protective factors, the role of binge drinking in HIV/AUD-linked cognitive decline, and whether neurocognitive and brain functions normalize after drinking cessation.

Sex Differences in the Patterns and Predictors of Cognitive Function in HIV

Despite advancements in antiretroviral therapy, mild cognitive deficits persist in nearly half of people with HIV (PWH). The profile of impairment in HIV is highly variable with deficits observed in a range of cognitive domains. Despite evidence of greater cognitive impairment among women with HIV (WWH) vs. men with HIV (MWH), it is unclear how MWH and WWH differ in the type of cognitive impairment and in risk factors associated with cognitive impairment profiles. In a large and well-characterized sample of PWH, we used machine learning to identify profiles of cognitive functioning and their associated factors overall and within sex. Participants included 1,666 PWH (201 WWH; 1,465 MMH) from the HIV Neurobehavioral Research Program who completed a neuropsychological test battery at their baseline visits. Using demographically-adjusted T-scores from 13 test outcomes assessing motor skills, executive functioning, attention/working memory, episodic learning and memory, verbal fluency, and processing speed, we used Kohonen self-organizing maps to identify patterns of high-dimensional data by mapping participants to similar nodes based on T-scores (MCLUST R package). Random forest models were used to determine how sociodemographic (e.g., age, education), clinical (e.g., depressive symptoms, substance use disorder), and biological (e.g., HIV disease characteristics) factors differentially related to membership within a cognitive profile. All analyses were repeated within sex. Three cognitive profiles were identified overall and within each sex. Overall and within MWH, there were unimpaired and global weakness profiles. The third profile in the total sample demonstrated relatively weak auditory attention whereas in MWH showed relative strengths in attention and processing speed. Conversely, there was no unimpaired profile among WWH. Rather, WWH demonstrated separate profiles reflecting weakness in motor skills, a relative weakness in learning and delayed recall, and global weaknesses with spared recognition memory. Despite different cognitive profiles by sex, the most discriminative factors were similar between men and women and included reading level (cognitive reserve), current and nadir CD4 count, plasma HIV viral load, duration of HIV disease, age, depressive symptoms, and race/ethnicity. Findings fill a knowledge gap concerning sex differences in cognitive impairment in PWH and inform personalized risk reduction and therapeutic strategies.

miR-149-5p inhibition reduces Alzheimer's disease β-amyloid generation in 293/APPsw cells by upregulating H4K16ac via KAT8

Alzheimer's disease (AD), the leading cause of age-related dementia, is characterized by abnormal β-amyloid accumulation. During learning, memory formation and consolidation, increased levels of histone H3 and H4 acetylation are observed. The present study reported significantly decreased level of H4K16ac in the plasma of patients with AD compared with healthy subjects via western blotting and reverse transcription-quantitative (RT-q)PCR. Lysine acetyltransferase 8 (KAT8) expression, the major lysine acetyltransferase responsible for the acetylation of H4K16, was significantly decreased in patients with AD compared with healthy subjects as determined via western blotting and RT-qPCR. The results indicated that aberrant expression patterns of H4K16ac and KAT8 might be associated with AD progression. Moreover, western blot analysis demonstrated that KAT8-overexpression cells displayed increased levels of H4K16ac, accompanied by higher levels of neuroprotective soluble amyloid precursor protein (sAPP)α and β-secretase (BACE)2, and decreased levels of sAPPβ and BACE1 compared with negative control and vector cells. In neurodegenerative disorders, microRNAs (miRNAs/miRs) are deregulated; however, the effect of miRNA dysregulation on histone acetylation is not completely understood. To the best of our knowledge, the present study identified a novel inhibitory interaction between miR-149-5p and KAT8 3'-UTR that contributed to the pathological alterations in an AD cell model for the first time, using bioinformatics and a dual-luciferase reporter assay. The western blotting results indicated that, compared with the inhibitor control group, miR-149-5p inhibitor markedly increased H4K16ac levels, which were significantly suppressed by co-transfection with KAT8 short hairpin (sh)RNA. KAT8 shRNA and miR-149-5p inhibitor co-transfection abolished the beneficial effects of miR-149-5p inhibitor. The results indicated that miR-149-5p regulated KAT8 and H4K16ac expression in an AD cell model, which may be associated with the pathological process of AD; therefore, miRNA may serve as a potential drug target for AD.

Effects of HIV infection, antiretroviral therapy, and immune status on the speed of information processing and complex motor functions in adult Cameroonians

HIV-associated neurocognitive deficits include impaired speed-of-information processing (SIP) and motor functions. There is lack of Cameroonian adult norms for assessing SIP or motor functions. This study of 683 Cameroonians (320 HIV+, 363 HIV-) establishes demographically-adjusted norms for six SIP [Wechsler-Adult-Intelligence-Scale (WAIS)-III Digit Symbol (WAIS-IIIDS) and Symbol Search (WAIS-IIISS), Stroop Color-Naming, Stroop Word-Reading, Trail-Making Test-A (TMT-A), Color Trails-1 (CTT1)], and two motor function [Grooved Pegboard-dominant (GP-DH) and non-dominant (GP-NDH) hands] tests. We assessed viral effects on SIP and motor functions. HIV-infected persons had significantly lower (worse) T scores on GP-DH, WAIS-IIIDS, Stroop Word-Reading, TMT-A; lower motor and SIP summary T scores. Significantly higher proportion of cases (20.7%) than controls (10.3%) had impaired SIP. Male cases had better T scores than female cases on GP-NDH, WAIS-IIIDS, WAIS-IIISS, TMT-A, CTT1; better SIP summary T scores. Antiretroviral therapy (ART) was associated with significantly better T scores on GP-NDH, WAIS-IIIDS, Stroop Color-Naming; better motor and SIP summary T scores. Cases with higher CD4 had better T scores on WAIS-IIIDS, TMT-A, CTT1; better SIP summary T scores. Overall, we demonstrate that HIV infection in Cameroon is associated with deficits in SIP and motor functions; ART and higher CD4 are associated with better cognitive performance. We provide SIP and psychomotor functions normative standards, which will be useful for neurobehavioral studies in Cameroon of diseases affecting the brain.

Sex differences and Tat expression affect dopaminergic receptor expression and response to antioxidant treatment in methamphetamine-sensitized HIV Tat transgenic mice

Methamphetamine (Meth) abuse is a common HIV comorbidity. Males and females differ in their patterns of Meth use, associated behaviors, and responses, but the underlying mechanisms and impact of HIV infection are unclear. Transgenic mice with inducible HIV-1 Tat protein in the brain (iTat) replicate many neurological aspects of HIV infection in humans. We previously showed that Tat induction enhances the Meth sensitization response associated with perturbation of the dopaminergic system, in male iTat mice. Here, we used the iTat mouse model to investigate sex differences in individual and interactive effects of Tat and Meth challenge on locomotor sensitization, brain expression of dopamine receptors (DRDs) and regulatory adenosine receptors (ADORAs). Because Meth administration increases the production of reactive oxygen species (ROS), we also determined whether the effects of Meth could be rescued by concomitant treatment with the ROS scavenger N-acetyl cysteine (NAC). After Meth sensitization and a 7-day abstinence period, groups of Tat+ and Tat-male and female mice were challenged with Meth in combination with NAC. We confirmed that Tat expression and Meth challenge suppressed DRD mRNA and protein in males and females' brains, and showed that females were particularly susceptible to the effects of Meth on D1-like and D2-like DRD subtypes and ADORAs. The expression of these markers differed strikingly between males and females, and between females in different phases of the estrous cycle, in a Tat -dependent manner. NAC attenuated Meth-induced locomotor sensitization and preserved DRD expression in all groups except for Tat + females. These data identify complex interactions between sex, Meth use, and HIV infection on addiction responses, with potential implications for the treatment of male and female Meth users in the context of HIV, especially those with cognitive disorders.

Greater Sensorimotor Deficits and Abnormally Lower Globus Pallidus Fractional Anisotropy in HIV+ Women than in HIV+ Men

AIMS

Cognitive impairment may be greater in HIV-positive (HIV+) women than in HIV+ men. Whether sex-specific differences exist in brain microstructure of HIV+ individuals is unknown and was evaluated.

METHOD

39 HIV+ (21 men, 18 women) and 45 seronegative (SN, 20 men, 25 women) participants were assessed with brain diffusion tensor imaging and cognitive assessments (7 neuropsychological domains). Fractional anisotropy (FA) and mean diffusivity (MD) were measured with an automated atlas in selected brain regions. Group comparisons were assessed with linear mixed effects models, with sub-regions and hemisphere (left/right) as repeated factors for each region.

RESULTS

HIV+ women, but not HIV+ men, were slower than sex-matched SN controls on sensorimotor function (Dominant-hand: interaction-p = 0.007; Non-dominant hand: interaction-p = 0.039). Similarly, only HIV+ women had lower FA in the globus pallidus (GP, interaction-p = 0.011). Additionally, regardless of sex, the HIV+ group had poorer Fluency, Speed, and Attention than SN-controls (p = 0.006-0.008), as well as lower FA and higher MD in multiple brain regions (p = <0.001-0.044). Across all participants, performance on Attention was predicted by uncinate-FA (p < 0.001, r = 0.5) and corpus callosum (CC)-FA (p = 0.038, r = 0.23), while the Speed of Information Processing was predicted by CC-FA (p = 0.009, r = 0.3). Furthermore, faster sensorimotor function correlated with higher CC-FA and uncinate-FA in men but not in women (Sex*DTI-interaction-p = 0.03-0.06).

CONCLUSIONS

The relatively poorer sensorimotor function and abnormally lower GP_FA, suggesting lesser neuronal integrity, in HIV+ women demonstrate sex-specific effects from HIV-infection on these measures. These findings may be related to the greater immune activation and neuroinflammation in HIV+ women compared to HIV+ men. Graphical Abstract.

Genetic variation in alcohol dehydrogenase is associated with neurocognition in men with HIV and history of alcohol use disorder: preliminary findings

The co-occurrence of HIV and alcohol use disorder (AUD) amplifies risk for neural injury and neurocognitive deficits. However, the substantial neurocognitive heterogeneity across HIV+/AUD+ individuals suggests inter-individual differences in vulnerability to the neurotoxicity of comorbid HIV/AUD. Genetic variation in alcohol dehydrogenase (ADH), which metabolizes ethanol, may contribute to inter-individual neurocognitive variability. We evaluated associations between five ADH single-nucleotide polymorphisms (SNPs) and neurocognition in men stratified by HIV and lifetime AUD status. Neurobehavioral assessments were administered to 153 men. Three-way ANOVAs examined the interaction of HIV, AUD, and ADH SNPs on global and domain-specific demographically corrected T scores. Follow-up ANCOVAs adjusted for age, estimated verbal IQ, depression, and remote non-alcohol substance use disorders. HIV/AUD groups differed globally and for verbal fluency, working memory, executive function, and processing speed T scores specifically, with HIV+/AUD+ exhibiting the poorest performance. ADH4 (rs1126671) was associated with large effects on working memory (d = - 1.16, p = .001) and executive function (d = - 0.77, p = .028) selectively in HIV+/AUD+, which remained significant in ANCOVA models. ADH1A (rs3819197) moderated the deleterious effects of HIV+/AUD+ on processing speed such that HIV+/AUD+ related to slower information processing in A allele carriers but not GG homozygotes (ps < 0.03). Preliminary findings suggest genetic variation in the ADH pathway moderates the deleterious neurocognitive effects of comorbid HIV/AUD. Differential metabolism of heavy ethanol exposure may compromise neurocognition under conditions of neurobiological stress, such as in HIV infection. The functional effects on ethanol metabolism of ADH SNPs examined in this study remain poorly understood, warranting further examination of pharmacokinetic mechanisms mediating ADH gene-neurobehavior relationships in HIV.

Neuronal-derived extracellular vesicles are enriched in the brain and serum of HIV-1 transgenic rats

Despite the efficacy of combination antiretroviral therapy (ART) in controlling human immunodeficiency virus (HIV-1) replication, cytotoxic viral proteins such as HIV-1 transactivator of transcription (Tat) persist in tissues such as the brain. Although HIV-1 does not infect neuronal cells, it is susceptible to viral Tat protein-mediated toxicity, leading to neuroinflammation that underlies HIV-associated neurocognitive disorders (HAND). Given the role of extracellular vesicles (EVs) in both cellular homoeostasis and under pathological conditions, we sought to investigate the alterations in the quantity of neuronal-derived EVs in the brain - as defined by the presence of cell adhesion molecule L1 (L1CAM) and to evaluate the presence of L1CAM⁺ EVs in the peripheral circulation of HIV-1 transgenic (HIV-1 Tg) rats. The primary goal of this study was to investigate the effect of long-term exposure of HIV-1 viral proteins on the release of neuronal EVs in the brain and their transfer in the systemic compartment. Brain and serum EVs were isolated from both wild type and HIV-1 Tg rats using differential ultracentrifugation with further purification using the Optiprep gradient method. The subpopulation of neuronal EVs was further enriched using immunoprecipitation. The current findings demonstrated increased presence of L1CAM⁺ neuronal-derived EVs both in the brain and serum of HIV-1 Tg rats.

HIV-1 infection alters energy metabolism in the brain: Contributions to HIV-associated neurocognitive disorders

The brain is particularly sensitive to changes in energy supply. Defects in glucose utilization and mitochondrial dysfunction are hallmarks of nearly all neurodegenerative diseases and are also associated with the cognitive decline that occurs as the brain ages. Chronic neuroinflammation driven by glial activation is commonly implicated as a contributing factor to neurodegeneration and cognitive impairment. Human immunodeficiency virus-1 (HIV-1) disrupts normal brain homeostasis and leads to a spectrum of HIV-associated neurocognitive disorders (HAND). HIV-1 activates stress responses in the brain and triggers a state of chronic neuroinflammation. Growing evidence suggests that inflammatory processes and bioenergetics are interconnected in the propagation of neuronal dysfunction. Clinical studies of people living with HIV and basic research support the notion that HIV-1 creates an environment in the CNS that interrupts normal metabolic processes at the cellular level to collectively alter whole brain metabolism. In this review, we highlight reports of abnormal brain metabolism from clinical studies and animal models of HIV-1. We also describe diverse CNS cell-specific changes in bioenergetics associated with HIV-1. Moreover, we propose that attention should be given to adjunctive therapies that combat sources of metabolic dysfunction as a mean to improve and/or prevent neurocognitive impairments.

Sex Differences in Neurocognitive Function in Adults with HIV: Patterns, Predictors, and Mechanisms

PURPOSE OF REVIEW

Sex differences in cognitive function are well documented yet few studies had adequate numbers of women and men living with HIV (WLWH; MLWH) to identify sex differences in neurocognitive impairment (NCI) and the factors contributing to NCI. Here, we review evidence that WLWH may be at greater risk for NCI.

RECENT FINDINGS

We conducted a systematic review of recent studies of NCI in WLWH versus MLWH. A power analysis showed that few HIV studies have sufficient power to address male/female differences in NCI but studies with adequate power find evidence of greater NCI in WLWH, particularly in the domains of memory, speed of information processing, and motor function. Sex is an important determinant of NCI in HIV, and may relate to male/female differences in cognitive reserve, comorbidities (mental health and substance use disorders), and biological factors (e.g., inflammation, hormonal, genetic).