Sex differences in neuropsychological performance as an effect of human immunodeficiency virus infection: a pilot study in Zambia, Africa

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.

Gendered differences in perceptions and reports of wellbeing: A cross-sectional survey of adults on ART in Malawi

Few studies have examined gender differences in reported quality of life among persons living with HIV (PLWH) in low-income countries. We conducted a cross-sectional survey of adults on antiretroviral therapy in Malawi, including questions focused on wellbeing, and collected clinical data on these respondents. We compared men's and women's self-reported health and wellbeing using Poisson models that included socio-demographic covariates. Approximately 20% of respondents reported at least one physical functioning problem. In multiple variable models, men were significantly more likely to have a high viral load (≥200 copies/mL; aIRR 2.57), consume alcohol (aIRR 12.58), receive no help from family or friends (aIRR 2.18), and to feel worthless due to their HIV status (aIRR 2.40). Men were significantly less likely to be overweight or obese (aIRR 0.31), or report poor health (health today is not "very good;" aIRR 0.41). Taken together, despite higher prevalence of poor self-rated health, women were healthier across a range of objective dimensions, with better viral suppression, less alcohol use, and less social isolation (although they were more likely to have an unhealthy BMI). Research that includes multi-dimensional and gender-specific measurement of physical, mental and social health is important for improving our understanding of well-being of PLWH.

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).

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.

A Multi-Dimensional Characterization of Aging and Wellbeing Among HIV-Positive Adults in Malawi

There is relatively little research on aging with HIV and wellbeing in sub-Saharan Africa. A cross-sectional survey was implemented in Malawi; eligible respondents were ≥ 30 years old and on ART for ≥ 2 years. Univariate and multiple regression analyses were stratified by age (younger adults: aged 30-49; older adults: aged ≥ 50) and gender. The median age was 51 years (total sample n = 134). Viral suppression was less common among older respondents (83.7% versus 93.0% among younger respondents) although not significant in adjusted models. Despite exhibiting worse physical and cognitive functioning (any physical functioning challenge: aOR 5.35, p = 0.02; cognitive functioning score difference: - 0.89 points, p = 0.04), older adults reported less interpersonal violence and fewer depressive symptoms (mild depression: aOR 0.23 p = 0.002; major depression: aOR 0.16, p = 0.004); in gender-stratified models, these relationships were significant only for females. More research is needed to disentangle the interplay between aging, gender and HIV in high-burden contexts and develop interventions to support comprehensive wellbeing in this population.

A longitudinal characterization of sex-specific somatosensory and spatial memory deficits in HIV Tg26 heterozygous mice

The pathogenesis of human immunodeficiency virus associated neurological disorders is still not well understood, yet is known to result in neurological declines despite combination anti-retroviral therapy. HIV-1 transgenic (Tg26) mice contain integrated non-infectious HIV-1 proviral DNA. We sought to assess the integrity of neurocognitive function and sensory systems in HIV-1 Tg26 mice using a longitudinal design, in both sexes, to examine both age- and sex-related disease progression. General neurological reflexive testing showed only acclimation to repeated testing by all groups. Yet, at 2.5 months of age, female Tg26 +/- mice showed hyposensitivity to noxious hot temperatures, compared to wild types (both sexes) and male Tg26 +/- mice, that worsened by 10 months of age. Female Tg26 +/- mice had short-term spatial memory losses in novel object location memory testing at 2.5 and 7 months, compared to female wild types; changes not observed in male counterparts. Female Tg26 +/- mice showed mild learning deficits and short- and long-term spatial memory deficits in olfactory and visually cued Barnes Maze testing at 3 months of age, yet greater learning and memory deficits by 8 months. In contrast, male Tg26 +/- mice displayed no learning deficits and fewer spatial memory deficits (mainly heading errors in nontarget holes). Thus, greater sex-specific temperature hyposensitivity and spatial memory declines were observed in female HIV Tg26 +/- mice, than in male Tg26 +/- mice, or their wild type littermates, that increased with aging. Additionally, tibial bones were examined using ex vivo micro-CT after tissue collection at 11 months. Sex-dependent increases in bone volume and trabecular number were seen in males, matching their greater weights at this age. These results indicate that HIV-1 Tg26 mice is a promising model in which to study neuropathic mechanisms underlying peripheral pathology as well as cognitive deficits seen with HIV.

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.

HIV-associated neurocognitive disorders at Moi teaching and referral hospital, Eldoret, Kenya

Background

Human Immunodeficiency Virus (HIV) infection causes a myriad of neurological complications including cognitive deficits referred to as HIV-Associated Neurocognitive Disorders (HAND). With the introduction of combination antiretroviral therapy, there has been an epidemiological shift in cognitive disorders with a decline in the more severe HIV-Associated Dementia (HAD) to an increase in the less severe HAND: Asymptomatic Neurocognitive Impairment (ANI) and HIV-associated Mild Neurocognitive Disorder (MND). Central Nervous System (CNS) involvement in HIV interferes with cognitively demanding activities of daily living and hence a worse quality of life. Early diagnosis is delayed until symptoms are overt.

Methods

We conducted a cross sectional analytical study of HIV infected persons on antiretroviral therapy attending HIV clinic. A systematic random sampling was done to select 360 patients. An interviewer administered structured questionnaire was used to collect socio-demographic data while the CD4 count and viral load were retrieved from the Academic Model Providing Access to Healthcare (AMPATH) database. Pearson’s Chi Square test was used to compare proportions while independent sample t- test was used to compare continuous variables between the patients diagnosed with HAND and those without HAND. Logistic regression model was used to assess the factors associated with HAND.

Results

The mean age of the study participants was 40.2 years. The overall prevalence of HAND was (81.1%) N = 292. Mild HAND (ANI and MND) was present (78.6%) N = 283, Severe HAND (HAD) (2.5%) N = 9. The factors associated with HAND were older age OR: 1.06 (95% CI: 1.03, 1.10), male gender OR: 0.48 (95% CI: 0.24, 0.97), Advanced WHO clinical staging OR: 2.45 (95% CI: 1.20, 5.01) and a higher level of education; secondary/tertiary OR: 0.16 (95% CI: 0.07, 0.38); 0.11 (95% CI: 0.04, 0.35).

Conclusion

The prevalence of HAND in this study population was found to be high (81.1%). Older age and advanced WHO clinical staging were associated with an increased risk of hand while higher level of education and male gender were protective.

Cultural Neuropsychology Considerations in the Diagnosis of HIV-Associated Neurocognitive Disorders

Human Immunodeficiency Virus Type-I (HIV) is a health disparities issue that affects culturally and linguistically diverse (CALD) and underrepresented minority populations to a greater degree than non-Hispanic white populations. Neurologically speaking, CALD populations experience worse HIV-related health outcomes, which are exacerbated by inadequate neurocognitive measures, poor normative samples, and the complex interplay of sociocultural factors that may affect test interpretation. Although cross-cultural neuropsychologists are working diligently to correct this gap in the literature, currently, studies examining neurocognitive outcomes among CALD populations are sparse. The most well-studied CALD groups are of African American/Black and Latinx adults in the US, and the chapter therefore focuses on these studies. There is more limited work among other populations in the US, such as Asians, Native Hawaiians, Pacific Islanders, and American Indians/Alaskan Natives, and even fewer studies for many CALD populations outside of the US. For example, HIV neuropsychology data is rare or nonexistent in the First Peoples of Australia and Indigenous People of Canada. It is often not adequately reported in Europe for the migrant populations within those countries or other world regions that have historically large multicultural populations (e.g., South America, Caribbean countries, Asia, and Africa). Therefore, this chapter reviews HIV-related health disparities faced by CALD populations with focus on North American research where it has been specifically studied, with particular attention given to disparities in HIV-Associated Neurocognitive Disorders (HAND). International data was also included for research with focus on First Peoples of Australia and Indigenous People of Canada. The chapter also examines other sociocultural and health factors, including global and regional (e.g., rural versus urban) considerations, migration, and gender. Further, guidelines for incorporating sociocultural consideration into assessment and interpretation of neurocognitive data and HAND diagnosis when working with HIV-positive CALD populations that would be relevant internationally are provided.

Cognitive Impairment in Zambians With HIV Infection and Pulmonary Tuberculosis

BACKGROUND

HIV infection may result in neurocognitive deficits, but the effects of pulmonary tuberculosis (TB+), a common comorbid condition in HIV infection, on cognition in HIV infections are unknown. Accordingly, we examined the effects of TB+, on neurocognitive functioning in HIV-infected (HIV+) Zambian adults.

SETTING

All participants were drawn from HIV clinics in and around Lusaka, the capital of Zambia.

METHODS

Participants were 275 HIV+, of whom 237 were HIV+ and TB-negative (HIV+/TB-), and 38 also had pulmonary TB+ (HIV+/TB+). Controls were 324 HIV- and TB-uninfected (HIV-) healthy controls. All HIV+ participants were prescribed combination antiretroviral treatment (cART). Published, demographically corrected Zambian neuropsychological norms were used to correct for effects of age, education, sex, and urban/rural residence.

RESULTS

Neuropsychological deficits, assessed by global deficit scores, were more prevalent in this order: 14% (46 of 324) of HIV- controls, 34% (80 of 237) of HIV+/TB-, and 55% (21 of 38) of HIV+/TB+ group. Thus, both HIV-infected groups evidenced more impairment than HIV- controls, and the HIV+/TB+ group had a higher rate of neurocognitive impairment than the HIV+/TB- group. HIV+/TB+ patients were more likely to be male, younger, less-educated, and have lower CD4 counts and detectable HIV RNA in blood compared with the HIV+/TB- patients.

CONCLUSIONS

In HIV infection, TB may contribute to cognitive impairment, even after controlling for lower CD4 counts and viral load. Thus, systemic inflammation from HIV and TB and more advanced immune deficiency at diagnosis of HIV may contribute to impaired cognition in HIV+/TB+ patients.

Plasma CXCL10 correlates with HAND in HIV-infected women

HIV-associated neurocognitive disorder (HAND) is characterized by chronic immune activation. We aimed to identify biomarkers associated with HAND and to investigate their association with cognitive function and sex, in a homogenous cohort of HIV-infected (HIV+) young adults, parenterally infected during early childhood. One hundred forty-four HIV+ Romanian participants (51% women) without major confounders underwent standardized neurocognitive and medical evaluation in a cross-sectional study. IFN-γ, IL-1β, IL-6, CCL2, CXCL8, CXCL10, and TNF-α were measured in plasma in all participants and in cerebrospinal fluid (CSF) in a subgroup of 56 study participants. Biomarkers were compared with neurocognitive outcomes, and the influence of sex and HIV disease biomarkers was assessed. In this cohort of young adults (median age of 24 years), the rate of neurocognitive impairment (NCI) was 36.1%. Median current CD4+ count was 479 cells/mm³ and 36.8% had detectable plasma viral load. Women had better HIV-associated overall status. In plasma, controlling for sex, higher levels of IL-6 and TNF-α were associated with NCI (p < 0.05). Plasma CXCL10 showed a significant interaction with sex (p = 0.02); higher values were associated with NCI in women only (p = 0.02). Individuals with undetectable viral load had significantly lower plasma CXCL10 (p < 0.001) and CCL2 (p = 0.02) levels, and CSF CXCL10 (p = 0.01), IL-6 (p = 0.04), and TNF-α (p = 0.04) levels. NCI in young men and women living with HIV was associated with higher IL-6 and TNF-α in plasma, but not in the CSF. CXCL10 was identified as a biomarker of NCI specifically in women with chronic HIV infection.

Neurorestoration of Sustained Attention in a Model of HIV-1 Associated Neurocognitive Disorders

Due to the sustained prevalence of human immunodeficiency virus (HIV)-1 associated neurocognitive disorders (HAND) in the post-combination antiretroviral therapy (cART) era, as well as the increased prevalence of older HIV-1 seropositive individuals, there is a critical need to develop adjunctive therapeutics targeted at preserving and/or restoring neurocognitive function. To address this knowledge gap, the present study examined the utility of S-Equol (SE), a phytoestrogen produced by gut microbiota, as an innovative therapeutic strategy. A signal detection operant task with varying signal durations (1,000, 500, 100 ms) was utilized to assess sustained attention in HIV-1 transgenic (Tg) and control animals. During the signal detection pretest assessment, HIV-1 Tg animals displayed profound deficits in stimulus-response learning and sustained attention relative to control animals. Subsequently, between 6 and 8 months of age, HIV-1 Tg and control animals were treated with a daily oral dose of either placebo or SE (0.05, 0.1, 0.2 mg) and a posttest assessment was conducted in the signal detection operant task with varying signal durations. In HIV-1 Tg animals, a linear decrease in the number of misses at 100 ms was observed as SE dose increased, suggesting a dose response with the most effective dose at 0.2 mg SE, approximating controls. Comparison of the number of misses across signal durations at the pretest and posttest revealed a preservation of neurocognitive function in HIV-1 Tg animals treated with 0.2 mg SE; an effect that was in sharp contrast to the neurocognitive decline observed in HIV-1 Tg animals treated with placebo. The results support the utility of 0.2 mg SE as a potential efficacious neuroprotective and/or neurorestorative therapeutic for sustained attention, in the absence of any adverse peripheral effects, in the HIV-1 Tg rat. Thus, the present study highlights the critical need for further in vivo studies to elucidate the full potential and generalizability of phytoestrogen treatment for HAND.

Inhibitory Control Deficits Associated with Upregulation of CB1R in the HIV-1 Tat Transgenic Mouse Model of Hand

In the era of combined antiretroviral therapy, HIV-1 infected individuals are living longer lives; however, longevity is met with an increasing number of HIV-1 associated neurocognitive disorders (HAND) diagnoses. The transactivator of transcription (Tat) is known to mediate the neurotoxic effects in HAND by acting directly on neurons and also indirectly via its actions on glia. The Go/No-Go (GNG) task was used to examine HAND in the Tat transgenic mouse model. The GNG task involves subjects discriminating between two stimuli sets in order to determine whether or not to inhibit a previously trained response. Data reveal inhibitory control deficits in female Tat(+) mice (p = .048) and an upregulation of cannabinoid type 1 receptors (CB₁R) in the infralimbic (IL) cortex in the same female Tat(+) group (p < .05). A significant negative correlation was noted between inhibitory control and IL CB₁R expression (r = −.543, p = .045), with CB₁R expression predicting 30% of the variance of inhibitory control (R² = .295, p = .045). Furthermore, there was a significant increase in spontaneous excitatory postsynaptic current (sEPSC) frequencies in Tat(+) compared to Tat(−) mice (p = .008, across sexes). The increase in sEPSC frequency was significantly attenuated by bath application of PF3845, a fatty acid amide hydrolase (FAAH) enzyme inhibitor (p < .001). Overall, the GNG task is a viable measure to assess inhibitory control deficits in Tat transgenic mice and results suggest a potential therapeutic treatment for the observed deficits with drugs which modulate endocannabinoid enzyme activity.

Graphical Abstract

The neurologic phenotype of South African patients with HIV-associated neurocognitive impairment

Background

The neurologic manifestations of HIV include a spectrum of HIV-associated neurocognitive disorders, as well as a cluster of neurologic symptoms and signs. The neurologic manifestations have been modified but not eradicated by antiretroviral therapy (ART). We describe the neurologic phenotype in South African patients with predominant HIV-1 subtype C infection on ART and its association with neurocognitive impairment and efavirenz and 8-hydroxy-efavirenz concentrations.

Methods

We conducted a cross-sectional analysis of the neurologic examination findings of HIV+ patients with neurocognitive impairment and used multiple linear regression to explore associations with neurocognitive impairment, efavirenz, and 8-hydroxy-efavirenz pharmacokinetics (plasma and CSF).

Results

We included 80 participants established on ART (median 40 months) of which 72 (90%) were female. The median age was 35 (interquartile range [IQR], 32-42) and the median Global Deficit Score was 0.94 (IQR 0.63-1.36). We found associations between neurocognitive impairment and neurologic signs: gait (slow walking speed [p = 0.03; R² = 0.06], gait ataxia [p < 0.01; R² = 0.21], and abnormal gait appearance [p < 0.01; R² = 0.18]); coordination (upper limb bradykinesia [p < 0.01; R² = 0.10] and lower limb bradykinesia [p = 0.01; R² = 0.10]); reflexes (jaw jerk [p = 0.04; R² = 0.05] and palmomental response [p = 0.03; R² = 0.06]); ocular signs (impaired smooth pursuit [p = 0.01; R² = 0.09] and impaired saccades [p < 0.01; R² = 0.15]); and motor signs (spasticity [p ≤ 0.01; R² = 0.15] and muscle weakness [p = 0.01; R² = 0.08]). No significant associations were found between plasma and CSF efavirenz or 8-hydroxy efavirenz concentrations and any neurologic sign.

Conclusion

We found that individual neurologic signs were associated with neurocognitive impairment in South African HIV+ patients with predominant HIV-1 subtype C infection on ART and could be used in clinical practice to assess severity.

Registration number

PACTR201310000635418.

HIV-1 and Compromised Adult Neurogenesis: Emerging Evidence for a New Paradigm of HAND Persistence

The face of the HIV-1/AIDS pandemic has changed significantly thanks to the development of antiretroviral therapy (ART) regimens. Unfortunately, several HIV-associated comorbidities continuously occur in the clinical population, most notably HIV-associated neurocognitive disorders (HAND). While many molecular and cellular mechanisms have been characterized by describing HAND pathology (specifically neuroinflammatory insults and oxidative stress) in the ART era, compromised adult neurogenesis is emerging as a potential new mechanism. Neurogenesis is a dynamic process that generates new neurons and glial cells from neural stem cells (NSCs) and neural progenitor cells (NPCs) in specific areas of the brain. There are increasing observations that HIV-1 can productively and non-productively infect NSCs and NPCs. HIV-1 proteins and/or secondary immune/inflammatory responses impair the initial differentiation process of NSCs to NPCs, restrict neuronal lineage differentiation, and aberrantly promote astrocytic lineage differentiation. Recent studies with HIV-1 transgenic animal models demonstrate varying degrees of adult neurogenic deficits, which correlate with milder to moderate forms of neurocognitive impairments. The neurogenic dysfunction underlying HAND highlights the importance of developing potential therapeutics to restore adult neurogenic homeostasis in HIV-1 patients.

Selective monoaminergic and histaminergic circuit dysregulation following long-term HIV-1 protein exposure

Between 30 and 60% of HIV-seropositive individuals develop symptoms of clinical depression and/or apathy. Dopamine and serotonin are associated with motivational alterations; however, histamine is less well studied. In the present study, we used fast-scan cyclic voltammetry in HIV-1 transgenic (Tg) rats to simultaneously analyze the kinetics of nucleus accumbens dopamine (DA), prefrontal cortical serotonin (5-HT), and hypothalamic histamine (HA). For voltammetry, subjects were 15 HIV-1 Tg (7 male, 8 female) and 20 F344/N (11 male, 9 female) adult rats. Both serotonergic and dopaminergic release and reuptake kinetics were decreased in HIV-1 Tg animals relative to controls. In contrast, rates of histamine release and reuptake increased in HIV-1 Tg rats. Additionally, we used immunohistochemical (IHC) methods to identify histaminergic neurons in the tuberomammillary nucleus (TMN) of the hypothalamus. For IHC, subjects were 9 HIV-1 Tg (5 male, 4 female) and 9 F344/N (5 male, 4 female) adult rats. Although the total number of TMN histaminergic cells did not differ between HIV-1 Tg rats and F344/N controls, a significant sex effect was found, with females having an increased number of histaminergic neurons, relative to males. Collectively, these findings illustrate neurochemical alterations that potentially underlie or exacerbate the pathogenesis of clinical depression and/or apathy in HIV-1.

Assessment of neurocognitive deficits in people living with HIV in Sub Saharan Africa: A systematic review

Objective: People living with HIV (PLWH) are at risk for HIV-Associated Neurocognitive Disorders (HAND)/Neurocognitive Impairment (NCI). HIV prevalence in Sub-Saharan Africa (SSA) is high, but neuropsychological screening and testing for NCI among HIV-infected individuals is not done frequently. This systematic review aims to establish how NCI among HIV-infected individuals is being assessed in SSA, if and how the tests are adapted, if norms exist and identify personnel who administer them.Method: We searched PubMed, Medline, EBSCO, PsycINFO, and Web of Science. Two reviewers screened the articles for inclusion and risk of bias. We included studies from SSA with a comprehensive neuropsychological assessment battery.Results: We retrieved 212 articles and 23 articles met inclusion criteria. The most commonly used tests were the Color Trails Test 1, Color Trails Test 2, and the WAIS III Digit Symbol Test. Some tests were translated into French (Cameroon), Luganda (Uganda), Chichewa (Malawi), isiXhosa (South Africa), and Afrikaans (South Africa). Some verbal learning tests were adapted to reflect culturally appropriate language. Test administrators were either non-specialized personnel supervised by clinical neuropsychologists or clinical psychologists.Conclusion: Overall, the tests used are similar to the tests being used globally to assess NCI among HIV-infected individuals and there is a general consistency across countries. However, there is generally a lack of norms for the tests and the process of adaptation is not always well described. Future research should establish whether these tests measure neuropsychological constructs as successfully as they do in western populations where the tests were developed.

Sex differences in neurocognitive screening among adults living with HIV in China

HIV-infected (HIV+) women may be more vulnerable to neurocognitive impairment (NCI) due to psychological and physiological factors but previous studies show mixed findings. We investigated the neurocognitive performances in HIV+ versus HIV- women and men. This cross-sectional analysis included 669 HIV+ patients (223 women) and 1338 HIV-uninfected (HIV-) controls (446 women) which were frequency matched on sex, education, and 5-year age categories. NCI was screened using the Mini-mental State Examination. Psychomotor speed was assessed using timed alternating hand sequence test. Prevalence of NCI was higher among women versus men in the HIV+ group (16.1% vs 10.5%) but not the HIV- group (4.3% vs 3.5%). HIV+ women performed worse compared to men on psychomotor speed, orientation, attention, and calculation, whereas HIV- women performed worse compared to men on attention and calculation. Adjusted interaction effects of HIV status × sex (women vs men) were significant on orientation, attention, and calculation, and marginally significant on psychomotor speed (p = 0.053). In multivariable models, among both HIV+ women and men, less years of education and depressive symptoms were associated with NCI. Waist-to-hip ratio above the cut-off was strongly associated with NCI among HIV+ women. HIV+ women perform worse on cognitive measures compared to HIV+ men. The association of central obesity with NCI in HIV+ women should be noted.

Neurocognitive Complications of HIV Infection in Women: Insights from the WIHS Cohort

Although sex differences in brain function and brain disorders are well documented, very few studies have had adequate number of women to address sex-related factors contributing to HIV-associated brain dysfunction. Compared to men living with HIV (MLWH), women living with HIV (WLWH) may be at greater risk for cognitive dysfunction and decline due to biological factors (e.g., hormonal, immunologic) and issues common in underserved communities including poverty, low literacy levels, mental health and substance abuse, barriers to health-care services, and environmental exposures. To address this issue, we review relevant cross-sectional and longitudinal findings from the Women's Interagency HIV Study (WIHS), the largest study of the natural and treated history of WLWH, as well as other studies focusing on cognitive complications of HIV in women. We provide evidence that WLWH are more cognitively vulnerable than MLWH and that there are differences in the pattern of cognitive impairment. We next discuss factors that contribute to these differences, including biological factors (e.g., inflammation, hormonal, genetic) as well as common comorbidities (mental health, substance use, vascular and metabolic risk factors, coinfections and liver function, non-antiretroviral medications, and genetic markers). These findings demonstrate the importance of considering sex as a biological factor in studies of cognitive dysfunction and suggest avenues for future research.

Sex differences in HIV-associated cognitive impairment

OBJECTIVE

We determined whether there are sex differences in the prevalence and profile of HIV-associated neurocognitive impairment, and whether sex moderates the effect of HIV-serostatus on neurocognitive impairment among HIV-positive and HIV-negative individuals. Secondarily, we assessed whether differences were explained by greater biopsychosocial risk factors in HIV-positive women.

DESIGN

An observational cohort study.

METHODS

Analyses included 1361 HIV-positive (204 women) and 702 HIV-negative (214 women) (ages = 18-79 years) participants from the UCSD HIV Neurobehavioral Research Program. Demographically corrected standardized T-scores from 15 neuropsychological tests were used to calculate domain-specific and global deficit scores (GDS). GDS at least 0.5 defined neurocognitive impairment. Biopsychosocial risk factors included low education, low reading level (education quality), lifetime substance use disorders, depressed mood (clinically significant depressive symptoms and/or current major depressive disorder) and a cumulative syndemic count (sum of biopsychosocial risk factors, range = 0-4). Race-stratified analyses were conducted. Analyses were adjusted for relevant demographic and clinical factors.

RESULTS

HIV-associated neurocognitive impairment was more prevalent in women versus men; however, the difference was eliminated after adjustment for reading level. In sex-stratified logistic regressions, the association between HIV-seropositivity and higher likelihood of neurocognitive impairment was stronger in women versus men; however, the association was attenuated in women, but not men, after adjusting for reading level. These results in the overall sample were specific to blacks. Sex differences in the profile of HIV-associated neurocognitive impairment varied by race.

CONCLUSION

Women, particularly black women, were most at-risk for HIV-associated neurocognitive impairment. Higher rates of HIV-associated neurocognitive impairment in women versus men may reflect differences in educational quality.

Synaptic Connectivity in Medium Spiny Neurons of the Nucleus Accumbens: A Sex-Dependent Mechanism Underlying Apathy in the HIV-1 Transgenic Rat

Frontal-subcortical circuit dysfunction is commonly associated with apathy, a neuropsychiatric sequelae of human immunodeficiency virus type-1 (HIV-1). Behavioral and neurochemical indices of apathy in the nucleus accumbens (NAc), a key brain region involved in frontal-subcortical circuitry, are influenced by the factor of biological sex. Despite evidence of sex differences in HIV-1, the effect of biological sex on medium spiny neurons (MSNs), which are central integrators of frontal-subcortical input, has not been systematically evaluated. In the present study, a DiOlistic labeling technique was used to investigate the role of long-term HIV-1 viral protein exposure, the factor of biological sex, and their possible interaction, on synaptic dysfunction in MSNs of the NAc in the HIV-1 transgenic (Tg) rat. HIV-1 Tg rats, independent of biological sex, displayed profound alterations in synaptic connectivity, evidenced by a prominent shift in the distribution of dendritic spines. Female HIV-1 Tg rats, but not male HIV-1 Tg rats, exhibited alterations in dendritic branching and neuronal arbor complexity relative to control animals, supporting an alteration in glutamate neurotransmission. Morphologically, HIV-1 Tg male, but not female HIV-1 Tg rats, displayed a population shift towards decreased dendritic spine volume, suggesting decreased synaptic area, relative to control animals. Synaptic dysfunction accurately identified presence of the HIV-1 transgene, dependent upon biological sex, with at least 80% accuracy (i.e., Male: 80%; Female: 90%). Collectively, these results support a primary alteration in circuit connectivity, the mechanism of which is dependent upon biological sex. Understanding the effect of biological sex on the underlying neural mechanism for HIV-1 associated apathy is vital for the development of sex-based therapeutics and cure strategies.

Evolutionary perspective on sex differences in the expression of neurological diseases

Sex-specific brain and cognitive deficits emerge with malnutrition, some infectious and neurodegenerative diseases, and often with prenatal or postnatal toxin exposure. These deficits are described in disparate literatures and are generally not linked to one another. Sexual selection may provide a unifying framework that integrates our understanding of these deficits and provides direction for future studies of sex-specific vulnerabilities. Sexually selected traits are those that have evolved to facilitate competition for reproductive resources or that influence mate choices, and are often larger and more complex than other traits. Critically, malnutrition, disease, chronic social stress, and exposure to man-made toxins compromise the development and expression of sexually selected traits more strongly than that of other traits. The fundamental mechanism underlying vulnerability might be the efficiency of mitochondrial energy capture and control of oxidative stress that in turn links these traits to current advances in neuroenergetics, stress endocrinology, and toxicology. The key idea is that the elaboration of these cognitive abilities, with more underlying gray matter or more extensive inter-modular white matter connections, makes them particularly sensitive to disruptions in mitochondrial functioning and oxidative stress. A framework of human sexually selected cognitive abilities and underlying brain systems is proposed and used to organize what is currently known about sex-specific vulnerabilities.

Verbal and spatial working memory among drug-using HIV-infected men and women

Working memory (WM) is a critical component of many neurocognitive functions. The literature has demonstrated consistently that WM impairment is more frequent and severe among substance-dependent individuals (SDIs) infected with HIV compared with uninfected SDIs; however, the SDIs who participated in these previous studies were primarily male. There are few published data on WM performance among HIV+ women with or without substance use disorders, and essentially no direct comparisons of WM performance between HIV+ men and women, regardless of substance use. We investigated potential sex and serostatus effects on WM among a sample of 360 SDIs (114 with HIV; 66% female) verified abstinent from alcohol and drugs of abuse at testing and generally comparable on substance use and comorbid characteristics. Participants were tested with the n-back task, a well-established WM measure that is sensitive to HIV-associated cognitive impairment. HIV+ men and women performed spatial and verbal versions of the n-back significantly less accurately compared with HIV- participants. Women showed slower response times compared with men on both versions, regardless of HIV serostatus. Individuals dependent on cocaine showed faster RTs compared with non-dependent users, but this effect was not apparent among opioid- or alcohol-dependent groups. Findings on n-back accuracy are consistent with our previous proposal that WM impairment represents a signature deficit among HIV+ SDIs; however, WM impairment appears less common among HIV+ women without a substance use history. The pattern of sex differences in response speed but serostatus effects on response accuracy is comparable to a recent report by our group of sex differences in learning speed but serostatus effects on delayed recall.

The Effect of a Short Period of Supplementation with Glutamine Dipeptide on the Cognitive Responses after a Resistance Training Session of Women with HIV/AIDS: A Randomized Double-Blind Placebo-Controlled Crossover Study

The aim of the present study was to investigate the effect of a short period of supplementation with glutamine dipeptide (GDP) on the acute responses to resistance training on the executive functions of people with HIV/AIDS. The sample consisted of 10 HIV+ women (45.00 ± 12.77 years old; 65.71 ± 12.04 kg; 1.54 ± 0.05 m) who were submitted to a randomized double-blind crossover procedure according to two experimental conditions: orally supplemented with 20 g/day of GDP or with maltodextrin for seven days. On the seventh day of supplementation all participants did cognitive function tests before and immediately after a resistance training session. Seven days of washout were adopted between conditions. Stroop and N-back tests were used to evaluate the executive functions. The training reduced the response time of each card in isolation and the latency time among them. GDP supplementation increased the magnitude of this effect, thus, reducing the latency time from the first to the last card in the Stroop test by almost 50% (P < 0.01). Considering the N-back test, there were no significant differences. It is suggested that GDP supplementation may increase the magnitude of the effect of an acute resistance training session in cognitive functions, particularly in the inhibitory control of people with HIV/AIDS. This trial is registered with NCT03236532.

Effect of age and level of education on neurocognitive impairment in HIV positive Zambian adults

OBJECTIVE

Older age and lower education levels are known to be associated with worse neurocognitive (NC) performance in healthy adults, and individuals with HIV infection may experience accelerated brain/cognition aging. However, higher education may possibly protect against HIV-associated neurocognitive disorders (HAND). The aim of the current cross-sectional study was to assess the effect of age and education in an HIV-1 clade C infected adult population in urban Zambia.

METHOD

Demographically corrected Zambian norms on a neuropsychological (NP) test battery were used to correct for normal age and education effects. The study assessed 286 HIV positive (+) males (37.1%) and females (62.9%) with a mean age of 41.35 (SD = 8.56) and mean years of education = 10.16 (SD = 2.18). A comprehensive NP test battery was used to assess cognitive domains frequently affected by HIV: attention/working memory, learning/and delayed recall, executive function, verbal fluency, processing speed, verbal and visual episodic memory, and fine motor skills.

RESULTS

In younger HIV+ Zambians, higher education evidenced protective effects against NC impairments overall, and for the specific domains of executive functions, learning and speed of information processing. Impairment scores did not support accelerated overall brain aging although the restricted age range and relative youth of our total sample may have precluded detection of such tendencies.

CONCLUSIONS

The present study raises the need to investigate factors that could be implicated in the poor neurocognitive performance among the younger, less educated HIV+ individuals in Zambia. (PsycINFO Database Record

Sex-based differences in neurocognitive functioning in HIV-infected young adults

INTRODUCTION

Sex differences in cognition of HIV positive (HIV) patients are controversial. We aimed to investigate the relationship between cognition, HIV status, and sex, in a highly homogenous cohort of young Romanians parenterally infected during early childhood.

METHODS

In total, 250 HIV participants were compared with age-matched HIV negative (HIV) controls (n = 72) in a cross-sectional study. After standardized neurocognitive, psychological testing and medical evaluation, linear regression was used to assess the effect of sex and HIV on neurocognitive outcomes.

RESULTS

Study participants were on average 23 years old with balanced sex distribution (% women = 52% vs. 43%). HIV were more educated (12.7 vs. 11.6 years, P = 0.002).HIV status was associated with a lower global performance (β = -0.22, P < 0.001), after controlling for age and education. HIV women had better previous and current HIV-associated markers. The effect of HIV on global cognition did not differ between sexes in most cognitive domains (β = 0.07, P = 0.14). An interaction between sex, HIV status, and cognitive functioning was found in the psychomotor domain. HIV women had worse motor skills than HIV women (β = -0.32, P < 0.001) suggesting a specific effect of HIV on motor functioning in women only. Moreover, current CD4 less than 200 cells/μl (P = 0.013) and longer time lived with CD4 less than 200 cells/μl (P = 0.023) were negatively correlated with the motor scaled score in women (β = -0.22, P = 0.034).

CONCLUSION

Despite less advanced disease in women, long-term HIV infection has an equally detrimental effect on cognitive performances of both sexes, in all cognitive domains, except the psychomotor domain where women are preferentially affected.

Sex Matters: Robust Sex Differences in Signal Detection in the HIV-1 Transgenic Rat

Sex differences in human immunodeficiency virus type-1 (HIV-1) have been repeatedly suggested. Females, who account for 51% of HIV-1 seropositive individuals, are inadequately represented in clinical and preclinical studies, as well as in the description of HIV-1 associated neurocognitive disorders (HAND). Direct comparisons of neurocognitive decline in women and men must be made to address this underrepresentation. The effect of biological sex (i.e., the biological factors, including chromosomes and hormones, determining male or female characteristics; WHO, 2017) on sustained attention, which is commonly impaired in HIV-1 seropositive individuals, was investigated in intact HIV-1 transgenic (Tg) and control animals using a signal detection operant task. Analyses revealed a robust sex difference in the rate of task acquisition, collapsed across genotype, with female animals meeting criteria in shaping (at least 60 reinforcers for three consecutive or five non-consecutive sessions) and signal detection (70% accuracy for five consecutive or seven non-consecutive sessions) significantly more slowly than male animals. Presence of the HIV-1 transgene also had a significant effect on shaping and signal detection acquisition, with HIV-1 Tg animals displaying significant deficits in the rate of acquisition relative to control animals–deficits that were more prominent in female HIV-1 Tg animals. Once the animals’ reached asymptotic performance in the signal detection task, female animals achieved a lower percent accuracy across test sessions and exhibited a decreased response rate relative to male animals, although there was no compelling evidence for any effect of transgene. Results indicate that the factor of biological sex may be a moderator of the influence of the HIV-1 transgene on signal detection. Understanding the impact of biological sex on neurocognitive deficits in HIV-1 is crucial for the development of sex-based therapeutics and cure strategies.

Sex differences in HIV effects on visual memory among substance-dependent individuals

HIV's effects on episodic memory have not been compared systematically between male and female substance-dependent individuals. We administered the Brief Visuospatial Memory Test-Revised (BVMT-R) to 280 substance-dependent HIV+ and HIV- men and women. Groups were comparable on demographic, substance use, and comorbid characteristics. There were no significant main effects of sex or HIV serostatus on BVMT-R performance, but HIV+ women performed significantly more poorly on delayed recall. This effect was most prominent among cocaine-dependent HIV+ women. Our findings are consistent with recent speculation that memory impairment may be more common among HIV+ women, particularly those with a history of cocaine dependence.

Impact of aging on neurocognitive performance in previously antiretroviral-naive HIV-infected individuals on their first suppressive regimen

BACKGROUND

Despite treatment with virologically suppressive antiretroviral therapy (ART), neurocognitive impairment may persist or develop de novo in aging HIV-infected individuals. We evaluated advancing age as a predictor of neurocognitive impairment in a large cohort of previously ART-naive individuals on long-term ART.

DESIGN

The AIDS Clinical Trials Group Longitudinal Linked Randomized Trials was a prospective cohort study of HIV-infected individuals originally enrolled in randomized ART trials. This analysis examined neurocognitive outcomes at least 2 years after ART initiation.

METHODS

All participants underwent annual neurocognitive testing consisting of Trail making A and B, the wechsler adult intelligence scale-revised Digit Symbol and Hopkins Verbal Learning Tests. Uni and multivariable repeated measures regression models evaluated factors associated with neurocognitive performance. Predictors at parent study entry (ART naive) included entry demographics, smoking, injection drug use, hepatitis B surface antigen, hepatitis C virus serostatus, history of stroke, ART regimen type, pre-ART nadir CD4 cell count, and plasma viral load and as well as time-updated plasma viral load and CD4 cell count.

RESULTS

The cohort comprised 3313 individuals with median pre-ART age of 38 years, 20% women; 36% Black, non-Hispanic; 22% Hispanic. Virologic suppression was maintained at 91% of follow-up visits. Neurocognitive performance improved with years of ART. After adjusting for the expected effects of age using norms from HIV-negative individuals, the odds of neurocognitive impairment at follow-up visits among the HIV infected increased by nearly 20% for each decade of advancing age.

CONCLUSION

Despite continued virologic suppression and neurocognitive improvement in the cohort as a whole, older individuals were more likely to have neurocognitive impairment than younger individuals.

Use of Western Neuropsychological Test Battery in Detecting HIV-Associated Neurocognitive Disorders (HAND) in Zambia

This is a study of neuroAIDS in sub-Saharan Africa, involving 266 Zambian adults infected with the human immunodeficiency virus (HIV), clade C. All HIV+ participants were receiving combination antiretroviral therapy (CART), and were administered a comprehensive neuropsychological (NP) test battery covering seven ability domains that are frequently affected by neuroAIDS. The battery was developed in the U.S. but has been validated in other international settings and has demographically-corrected normative standards based upon 324 healthy Zambian adults. Compared to the healthy Zambian controls, the HIV+ sample performed worse on the NP battery with a medium effect size (Cohen's d = 0.64). 34.6 % of the HIV+ individuals had global NP impairment and met criteria for HIV associated neurocognitive disorder (HAND). The results indicate that the Western-developed NP test battery is appropriate for use in Zambia and can serve as a viable HIV and AIDS management tool.

Impairments of Motor Function While Multitasking in HIV

Human immunodeficiency virus (HIV) became a treatable illness with the introduction of combination antiretroviral therapy (CART). As a result, patients with regular access to CART are expected to live decades with HIV. Long-term HIV infection presents unique challenges, including neurocognitive impairments defined by three major stages of HIV-associated neurocognitive disorders (HAND). The current investigation aimed to study cognitive and motor impairments in HIV using a novel multitasking paradigm. Unlike current standard measures of cognitive and motor performance in HIV, multitasking increases real-world validity by mimicking the dual motor and cognitive demands that are part of daily professional and personal settings (e.g., driving, typing and writing). Moreover, multitask assessments can unmask compensatory mechanisms, normally used under single task conditions, to maintain performance. This investigation revealed that HIV+ participants were impaired on the motor component of the multitask, while cognitive performance was spared. A patient-specific positive interaction between motor performance and working memory recall was driven by poor HIV+ multitaskers. Surprisingly, HAND stage did not correspond with multitask performance and a variety of commonly used assessments indicated normal motor function among HIV+ participants with poor motor performance during the experimental task. These results support the use of multitasks to reveal otherwise hidden impairment in chronic HIV by expanding the sensitivity of clinical assessments used to determine HAND stage. Future studies should examine the capability of multitasks to predict performance in personal, professional and health-related behaviors and prognosis of patients living with chronic HIV.

Cerebrospinal fluid (CSF) biomarkers of iron status are associated with CSF viral load, antiretroviral therapy, and demographic factors in HIV-infected adults

Background

HIV-associated neurocognitive disorder (HAND) remains common, despite antiretroviral therapy (ART). HIV dysregulates iron metabolism, but cerebrospinal fluid (CSF) levels of iron and iron-transport proteins in HIV-infected (HIV+) persons are largely unknown. The objectives of this study were to characterize CSF iron-related biomarkers in HIV+ adults and explore their relationships to known predictors of HAND.

Methods

We quantified total iron, transferrin and heavy-chain (H)-ferritin by immunoassay in CSF sampled by lumbar puncture in 403 HIV+ participants in a multi-center, observational study and evaluated biomarker associations with demographic and HIV-related correlates of HAND [e.g., age, sex, self-reported race/ethnicity, ART, and detectable plasma virus and CSF viral load (VL)] by multivariable regression. In a subset (N = 110) with existing CSF: serum albumin (Q_Alb) measurements, Q_Alb and comorbidity severity were also included as covariates to account for variability in the blood–CSF-barrier.

Results

Among 403 individuals (median age 43 years, 19% women, 56% non-Whites, median nadir CD4+ T cell count 180 cells/µL, 46% with undetectable plasma virus), men had 25% higher CSF transferrin (median 18.1 vs. 14.5 µg/mL), and 71% higher H-ferritin (median 2.9 vs. 1.7 ng/mL) than women (both p-values ≤0.01). CSF iron was 41% higher in self-reported Hispanics and 27% higher in (non-Hispanic) Whites than in (non-Hispanic) Blacks (median 5.2 and 4.7 µg/dL in Hispanics and Whites, respectively, vs. 3.7 µg/dL in Blacks, both p ≤ 0.01); these findings persisted after adjustment for age, sex, and HIV-specific factors. Median H-ferritin was 25% higher (p < 0.05), and transferrin 14% higher (p = 0.06), in Whites than Blacks. Transferrin and H-ferritin were 33 and 50% higher, respectively, in older (age > 50 years) than in younger persons (age ≤ 35 years; both p < 0.01), but these findings lost statistical significance in subset analyses that adjusted for Q_Alb and comorbidity. After these additional adjustments, associations were observed for CSF iron and transferrin with race/ethnicity as well as CSF VL, for transferrin with sex and ART, and for H-ferritin with plasma virus detectability and significant comorbidity (all p < 0.05).

Conclusions

CSF iron biomarkers are associated with demographic factors, ART, and CSF VL in HIV+ adults. Future studies should investigate a role for CNS iron dysregulation, to which an altered blood-CSF barrier may contribute, in HAND.

Electronic supplementary material

The online version of this article (doi:10.1186/s12987-017-0058-1) contains supplementary material, which is available to authorized users.

Progression of temporal processing deficits in the HIV-1 transgenic rat

The HIV-1 transgenic (Tg) rat, which expresses 7 of the 9 HIV-1 genes, was used to investigate the effect(s) of long-term HIV-1 viral protein exposure on chronic neurocognitive deficits observed in pediatric HIV-1 (PHIV). A longitudinal experimental design was used to assess the progression of temporal processing deficits, a potential underlying dimension of neurocognitive impairment in HIV-1. Gap prepulse inhibition (gap-PPI), a translational experimental paradigm, was conducted every thirty days from postnatal day (PD) 30 to PD 180. HIV-1 Tg animals, regardless of sex, displayed profound alterations in the development of temporal processing, assessed using prepulse inhibition. A differential sensitivity to the manipulation of interstimulus interval was observed in HIV-1 Tg animals in comparison to control animals. Moreover, presence of the HIV-1 transgene was diagnosed with 90.8% accuracy using measures of prepulse inhibition and temporal sensitivity. Progression of temporal processing deficits in the HIV-1 Tg rat affords a relatively untapped opportunity to increase our mechanistic understanding of the role of long-term exposure to HIV-1 viral proteins, observed in pediatric HIV-1, in the development of chronic neurological impairment, as well as suggesting an innovative clinical diagnostic screening tool.

The burden of HIV-associated neurocognitive disorder (HAND) in the Asia-Pacific region and recommendations for screening

BACKGROUND

HIV-associated neurocognitive disorder incurs a significant burden on HIV patients in Asia-Pacific countries; however, the incidence is difficult to estimate due to a lack of local epidemiological data. The impact of neurocognitive impairment in HIV patients is often underestimated due to a lack of education and awareness, and there are consequently gaps in the provision of screening and diagnosis to enable earlier intervention to limit neurocognitive impairment.

METHOD

This review seeks to redress the imbalance by promoting awareness and education among physicians concerning the neurovirulence of HIV and thereby increase screening efforts to improve diagnosis rates and clinical outcomes for underserved patients in this region. The Asia, Australia, and Middle East (AAME) HAND Advisory Board convened expert regional representatives to review current practice and recommend appropriate measures related to the implementation of standardised screening programmes and treatment recommendations to curb the developing HAND epidemic in the region. In particular, we recommend basic neuropsychological testing protocols that could be efficiently introduced into clinical practice for routine screening.

RESULT

We also propose simple guidelines for the management of HAND. We believe that HAND is a significant and under-reported diagnosis in HIV patients that warrants both greater recognition and further clinical investigation of the underlying pathophysiology and the impact of HIV disease progression, with HAND being associated with worse medication adherence and therefore possibly increased risk of ARV treatment failure.

DISCUSSION

Widespread screening will lead to greater recognition of HAND and earlier intervention, which may lead to improved management strategies in the future.

Sex differences in soluble markers vary before and after the initiation of antiretroviral therapy in chronically HIV-infected individuals

OBJECTIVE

To evaluate differences in soluble inflammatory markers between chronically HIV-infected men and women, with or without cognitive impairment, and in response to treatment.

DESIGN

Soluble biomarkers were measured in cryopreserved plasma and cerebrospinal fluid (CSF) of 60 treatment-naïve individuals (25 men and 35 women) with chronic HIV infection and 18 HIV-uninfected controls (9 men and 9 women) from Thailand. Following enrollment, participants began combination antiretroviral therapy and were evaluated for expression of these markers after 48 weeks.

METHODS

Plasma and CSF levels of 19 soluble biomarkers (IFN-γ, TNFα, TNF-RII, IL-1α, IL-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-15, MCP-1, t-Tau, IP-10, neopterin, IFNα, I-FABP, and sCD14) were measured using either a multiparameter or standard ELISA assay.

RESULTS

Prior to combination antiretroviral therapy, women with impaired cognition had elevated levels of neopterin and TNF-RII compared with women with normal cognition in both the plasma and CSF; however, levels did not differ between cognitively impaired or normal men. In a secondary outcome-hypothesis generating analysis, sex differences were also pronounced in plasma levels of MCP-1, IL-10, I-FABP, and sCD14 in response to treatment. Neopterin, IP-10, TNFα, TNF-RII, IFNα, MCP-1, IL-8, I-FABP, and sCD14 plasma levels remained elevated following 48 weeks of therapy in both sexes compared with uninfected controls.

CONCLUSION

We provide evidence of sustained immune activation after 48 weeks of treatment and identify possible sex differences in biomarkers previously linked to cognitive impairment, chronic inflammation, and gut integrity that may contribute to immunological differences between sexes in relationship to disease progression and response to therapy.

Diagnostic Accuracy, Sensitivity, and Specificity of Executive Function Tests in Moderate Traumatic Brain Injury in Ghana

The sociocultural differences between Western and sub-Saharan African countries make it imperative to standardize neuropsychological tests in the latter. However, Western-normed tests are frequently administered in sub-Saharan Africa because of challenges hampering standardization efforts. Yet a salient topical issue in the cross-cultural neuropsychology literature relates to the utility of Western-normed neuropsychological tests in minority groups, non-Caucasians, and by extension Ghanaians. Consequently, this study investigates the diagnostic accuracy, sensitivity, and specificity of executive function (EF) tests (The Stroop Test, Trail Making Test, and Controlled Oral Word Association Test), and a Revised Quick Cognitive Screening Test (RQCST) in a sample of 50 patients diagnosed with moderate traumatic brain injury and 50 healthy controls in Ghana. The EF test scores showed good diagnostic accuracy, with area under the curve (AUC) values of the Trail Making Test scores ranging from .746 to .902. With respect to the Stroop Test scores, the AUC values ranged from .793 to .898, while Controlled Oral Word Association Test had AUC value of .787. The RQCST scores discriminated between the groups, with AUC values ranging from .674 to .912. The AUC values of composite EF score and a neuropsychological score created from EF and RQCST scores were .936 and. 942, respectively. Additionally, the Stroop Test, Trail Making Test, EF composite score, and RQCST scores showed good to excellent sensitivities and specificities. In general, this study has shown that commonly used EF tests in Western countries have diagnostic accuracy, sensitivity, and specificity when administered in Ghanaian samples. The findings and implications of the study are discussed.

Associations between Cognition, Gender and Monocyte Activation among HIV Infected Individuals in Nigeria

The potential role of gender in the occurrence of HIV-related neurocognitive impairment (NCI) and associations with markers of HIV-related immune activity has not been previously examined. In this study 149 antiretroviral-naïve seropositive subjects in Nigeria (SP, 92 women and 57 men) and 58 seronegative (SN, 38 women and 20 men) were administered neuropsychological testing that assessed 7 ability domains. From the neuropsychological test scores was calculated a global deficit score (GDS), a measure of overall NCI. Percentages of circulating monocytes and plasma HIV RNA, soluble CD163 and soluble CD14 levels were also assessed. HIV SP women were found to be younger, more educated and had higher CD4+ T cell counts and borderline higher viral load measures than SP men. On the neuropsychological testing, SP women were more impaired in speed of information processing and verbal fluency and had a higher mean GDS than SN women. Compared to SP men, SP women were also more impaired in speed of information processing and verbal fluency as well as on tests of learning and memory. Numbers of circulating monocytes and plasma sCD14 and sCD163 levels were significantly higher for all SP versus all SN individuals and were also higher for SP women and for SP men versus their SN counterparts. Among SP women, soluble CD14 levels were slightly higher than for SP men, and SP women had higher viral load measurements and were more likely to have detectable virus than SP men. Higher sCD14 levels among SP women correlated with more severe global impairment, and higher viral load measurements correlated with higher monocyte numbers and sCD14 and sCD14 levels, associations that were not observed for SP men. These studies suggest that the risk of developing NCI differ for HIV infected women and men in Nigeria and, for women, may be linked to effects from higher plasma levels of HIV driving activation of circulating monocytes.

Prevalence of neurocognitive disorders and depression in a Brazilian HIV population

INTRODUCTION

Combined antiretroviral therapy has enabled human immunodeficiency virus (HIV) carriers to live longer. This increased life expectancy is associated with the occurrence of degenerative diseases, including HIV-associated neurocognitive disorders (HAND), which are diagnosed via a complex neuropsychological assessment. The International HIV Dementia Scale (IHDS) is a screening instrument validated in Brazil for use in the absence of neuropsychological evaluation. HIV patients are frequently diagnosed with depression. We aimed to determine the prevalence of neurocognitive impairment using the IHDS and depressive disorders using the Hamilton Rating Scale for Depression (HAM-D17), compare the IHDS performance with the performances on the Timed Gait Test (TGT), the Digit Symbol Coding Test (DS) and the Brazilian version of the Scale of Instrumental Activities of Daily Living (IADL), and evaluate the association between the IHDS performance and clinical-demographic variables.

METHODS

One hundred fourteen patients were evaluated in a cross-sectional study conducted in a public outpatient clinic for infectious diseases in Marília City, State of São Paulo, Brazil. Data were collected following consultation. Statistical analysis was performed in accordance with the nature and distribution of the data and hypotheses.

RESULTS

According to the IHDS, 53.2% of the sampled patients were neuropsychologically impaired. According to the HAM-D17, 26.3% had depressive disorders. There were significant associations between the IHDS and the TGT and DS. Multiple regression analysis indicated that female gender, educational level, and cluster of differentiation 4 (CD4) levels were significantly and independently associated with neurocognitive impairment.

CONCLUSIONS

The prevalence of neurocognitive impairment according to the IHDS is high and associated with female gender, education level, and low CD4 levels.

HIV- and AIDS-associated neurocognitive functioning in Zambia - a perspective based on differences between the genders

Human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) are frequently associated with neurocognitive impairment (NCI). However, few studies have examined the interrelationship between gender and NCI in the HIV and AIDS population. This cross-sectional study examined the neurocognitive (NC) functioning of HIV-infected male and female adults from urban Zambia. The participants included 266 HIV seropositive (HIV+) adults (males [n=107] and females [n=159]). Participants completed NC assessment by means of a comprehensive test battery using normative data from 324 HIV-seronegative (HIV-) controls. The norms corrected for effects of age, education, and gender in the general population, and the test battery measures domains of attention/working memory (learning and delayed recall), executive function, verbal fluency, processing speed, verbal and visual episodic memory, and fine motor skills. An overall comparison of the HIV+ male and female participants yielded no statistically significant differences. Analysis of covariance results controlling for disease characteristics showed that HIV+ female participants had worse delayed recall scores than males, F(1,117) =9.70, P=0.002, partial η(2)=0.077. The females also evidenced a trend toward greater impairment on learning efficiency (P=0.015). The findings suggest that there are gender-related differences in NCI after controlling for disease characteristics. It was observed that although the HIV+ females enjoyed better health compared to their HIV+ male counterparts, they still had worse performance on the neuropsychological tests. This implies that HIV may have more NC consequences for Zambian females than males.

Chronic HIV-1 Tat and HIV reduce Rbfox3/NeuN: evidence for sex-related effects

The NeuN antibody has been widely used to identify and quantify neurons in normal and disease situations based on binding to a nuclear epitope in most types of neurons. This epitope was recently identified as the RNA-binding, feminizing locus on X-3 (Rbfox3), a member of the larger, mammalian Fox1 family of RNA binding proteins. Fox1 proteins recognize a unique UGCAUG mRNA motif and regulate alternative splicing of precursor mRNA to control post-transcriptional events important in neuronal differentiation and central nervous system development. Recent clinical findings show that Rbfox3/NeuN gene dosage is altered in certain human neurodevelopmental disorders, and redistribution has been noted in HIV(+) tissue. We hypothesized that HIV-1 Tat might affect Rbfox3/NeuN expression, and examined this question in vivo using inducible transgenic mice, and in vitro using human mesencephalic-derived neurons. Rbfox3/NeuN expression and localization in HIV+ basal ganglia and hippocampus was also examined. Chronic Tat exposure reduced Rbfox3/NeuN protein levels and increased cytoplasmic localization, similar to the effect of HIV exposure. Cytoplasmic Rbfox3/NeuN signal has occasionally been reported, although the meaning or function of cytoplasmic versus nuclear localization remains speculative. Importantly, Rbfox3/NeuN reductions were more significant in male mice. Although Rbfox3/NeuN-expressing cells were significantly decreased by Tat exposure, stereology showed that Nissl(+) neuron numbers remained normal. Thus, loss of Rbfox3/NeuN may relate more to functional change than to neuron loss. The effects of Tat by itself are highly relevant to HIV(+) individuals maintained on antiretroviral therapy, since Tat is released from infected cells even when viral replication is inhibited.

Executive Dyscontrol of Learning and Memory: Findings from a Clade C HIV-positive South African Sample

OBJECTIVE

Although pre-clinical work suggests there might be differences in neurovirulence across HIV-1 clades, few studies investigate neuropsychological deficits in the globally predominant clade C infection. The purpose of this study was to investigate verbal learning and memory performance in HIV-positive individuals in Cape Town, South Africa, where clade C is the most prevalent subtype of the virus.

METHOD

Using a case-control design, we recruited 53 isiXhosa-speaking, cART-naïve HIV-positive adults and 53 demographically matched HIV-negative controls. Participants were administered a comprehensive neuropsychological test battery. The test of interest was the Hopkins Verbal Learning Test-Revised (HVLT-R); previous studies have used that instrument to identify executive dyscontrol of verbal learning and memory processes in clade B HIV-positive participants.

RESULTS

HIV-positive participants showed only partial impairment on the HVLT-R's learning/memory components (e.g., they recalled significantly fewer words across learning trials, but displayed relatively intact performance on delayed recall trials). They also displayed little executive dyscontrol over encoding and retrieval processes (e.g., there were no significant between-group differences on measures of semantic or serial clustering).

CONCLUSIONS

Post-cART era studies suggest that verbal learning and memory performance is impaired in clade B samples, at least partially due to executive dyscontrol over encoding and retrieval processes. We found few such impairments in the current clade C sample. These preliminary findings suggest different CNS vulnerability across clades that would have implications for delineating clade-specific neuropathological and neurocognitive clinical features.

Human immunodeficiency virus has similar effects on brain volumetrics and cognition in males and females

Most studies that have examined neuropsychological impairments associated with human immunodeficiency virus (HIV) have focused on males, yet females represent one of the largest groups of newly infected patients. Further, few studies have examined neuropsychological performance and neuroimaging outcomes among females compared to males in the modern era of highly active anti-retroviral therapy (HAART). The present study investigated neuropsychological performance and brain volumetrics among HIV+ males (n = 93) and females (n = 44) on stable HAART compared to HIV seronegative (HIV-) males (n = 42) and females (n = 49). Results revealed a significant effect of HIV on neuropsychological performance and neuroimaging measures. An effect of gender, independent of HIV status, was also observed for neuroimaging measures but not neuropsychological performance. Additionally, no significant differences in neuropsychological performance or brain volumetrics were seen between HIV+ males and females. No significant interaction was observed between HIV and gender on either neuropsychological or neuroimaging indices. Our results suggest that both HIV+ males and females treated with HAART experience similar outcomes in terms of brain integrity.

Do neuropsychological test norms from African Americans in the United States generalize to a Zambian population?

Healthy Zambian adults (N = 324) were evaluated to determine to what degree a Western neuropsychological (NP) test battery, with African American norms adjusted for age, gender, and education could be used in healthy Zambians, including 157 men (48.46%) and 167 women (51.54%) with an average age of 38.48 (SD = 12.80) years and an average education level of 11.02 (SD = 2.58) years. The NP battery included tests of attention/working memory, executive function, verbal fluency, processing speed, verbal and visual episodic memory, and fine motor skills. The Zambian Achievement Test (ZAT) and the U.S. Wide Range Achievement Test-4 (WRAT-4) reading subtest also were administered to assess literacy and quality of education. Similar to findings in Western countries, the Zambian results show substantial age and education effects on most tests and smaller, less consistent effects of gender. Beyond the basic demographic effects, urban/rural background had small effects on some cognitive variables, and the ZAT (but not WRAT-4) reading level was a robust predictor of performance on many NP tests, even when other background characteristics were controlled. Women in the United States tend to outperform men on tests of processing speed and episodic memory. However, Zambian women showed modest but statistically significant disadvantages versus their male counterparts. The results show that tests developed in the United States may be used in Zambia. Nevertheless, development and use of local cultural norms remains very important and is a must. New demographically corrected norms were developed for the cohort that was examined.

Grooved Pegboard for adult employed South Africans: normative data and human immunodeficiency virus associations

The Grooved Pegboard is a widely used test of psychomotor speed, and currently is used in particular to assess HIV-associated neurocognitive decline. To accurately interpret any assessment, appropriate reference norms are required. Although South Africa has the highest number of people living with HIV and AIDS, no local large scale reference data are available for the Grooved Pegboard. The main objective of the study was to formulate reference data for healthy adult South Africans in formal employment; two secondary objectives aimed to statistically explore the available Grooved Pegboard performance data, as well as its association with HIV status. Data were collected as part of multi-disciplinary occupational health screening, and included healthy HIV− adults ( N = 3118), and 70 HIV+ participants. This article presents normative reference data stratified across age and gender categories. The South African scores differ from other reported samples, emphasising the need to develop local norms that are context based, to facilitate clinical interpretation of psychomotor performance. Furthermore, in this sample, the Grooved Pegboard differentiated significantly between asymptomatic HIV+ persons, and those with HIV-associated neurocognitive disorders, although with poor predictive ability. In conclusion, large-sample reference data for healthy employed adult South Africans (age 19–59) are reported across gender and age categories, and may assist in more accurate screening of psychomotor speed generally, and HIV-associated neurocognitive decline in particular.

The relationship between HIV and prevalence of disabilities in sub-Saharan Africa: systematic review (FA)

OBJECTIVE

To systematically review evidence on the prevalence and risk of disabilities among children and adults living with HIV in sub-Saharan Africa.

METHODS

Articles were identified from 1980 to June 2013 through searching seven electronic databases. Epidemiological studies conducted in sub-Saharan Africa that explored the association between HIV status and general disability or specific impairments, with or without an HIV-uninfected comparison group, were eligible for inclusion.

RESULTS

Of 12 867 records initially identified, 61 papers were deemed eligible for inclusion. The prevalence of disability was high across age groups, impairment types and study locations. Furthermore, 73% of studies using an HIV- comparator found significantly lower levels of functioning in people living with HIV (PLHIV). By disability type, the results were as follows: (i) for studies measuring physical impairments (n = 14), median prevalence of limitations in mobility and motor function among PLHIV was 25.0% (95% CI: 21.8-28.2%). Five of eight comparator studies found significantly reduced functioning among PLHIV; for arthritis, two of three studies which used an HIV- comparison group found significantly increased prevalence among PLHIV; (ii) for sensory impairment studies (n = 17), median prevalence of visual impairment was 11.2% (95%CI: 9.5-13.1%) and hearing impairment was 24.1% (95%CI: 19.2-29.0%) in PLHIV. Significantly increased prevalence among PLHIV was found in one of four (vision) and three of three studies (hearing) with comparators; (iii) for cognitive impairment in adults (n = 30), median prevalence for dementia was 25.3% (95% CI: 22.0-28.6%) and 40.9% (95% CI: 37.7-44.1%) for general cognitive impairment. Across all types of cognitive impairment, twelve of fourteen studies found a significant detrimental effect of HIV infection; (iv) for developmental delay in children with HIV (n = 20), median prevalence of motor delay was 67.7% (95% CI: 62.2-73.2%). All nine studies that included a comparator found a significant difference between PLHIV and controls; for cognitive development and global delay, a significant detrimental effect of HIV was found in five of six and one of two studies, respectively. In the nine cohort studies comparing vertically infected and uninfected children, eight showed a significant gap in development over time in children with HIV. Finally, fifteen of thirty-one (48%) studies found a statistically significant dose-response relationship between indicators of disease progression (CD4 or WHO stage) and disability.

CONCLUSIONS

HIV is widespread in sub-Saharan Africa and the evidence suggests that it is linked to disabilities, affecting a range of body structures and functions. More research is needed to better understand the implications of HIV-related disability for individuals, their families as well as those working in the fields of disability and HIV so that appropriate interventions can be developed.

Cognitive impairment and psychiatric morbidity in HIV+ Zambians with new-onset seizure

A prospective cohort study of new-onset seizure in people with human immunodeficiency virus (HIV) in Zambia is ongoing to determine the incidence of subsequent epilepsy and risk factors for epileptogenesis in this population. At enrollment, we evaluated this cohort for cognitive impairment and psychiatric morbidity. Over 50% of participants had cognitive impairment and significant psychiatric morbidity. Most participants had advanced HIV disease based on CD4+ T-cell count and World Health Organization stage, but we found no association between cognitive impairment or psychiatric morbidity and HIV disease staging.

Host genetic factors predisposing to HIV-associated neurocognitive disorder

The success of combination antiretroviral therapy (cART) in transforming the lives of HIV-infected individuals with access to these drugs is tempered by the increasing threat of HIV-associated neurocognitive disorders (HAND) to their overall health and quality of life. Intensive investigations over the past two decades have underscored the role of host immune responses, inflammation, and monocyte-derived macrophages in HAND, but the precise pathogenic mechanisms underlying HAND remain only partially delineated. Complicating research efforts and therapeutic drug development are the sheer complexity of HAND phenotypes, diagnostic imprecision, and the growing intersection of chronic immune activation with aging-related comorbidities. Yet, genetic studies still offer a powerful means of advancing individualized care for HIV-infected individuals at risk. There is an urgent need for 1) longitudinal studies using consistent phenotypic definitions of HAND in HIV-infected subpopulations at very high risk of being adversely impacted, such as children, 2) tissue studies that correlate neuropathological changes in multiple brain regions with genomic markers in affected individuals and with changes at the RNA, epigenomic, and/or protein levels, and 3) genetic association studies using more sensitive subphenotypes of HAND. The NIH Brain Initiative and Human Connectome Project, coupled with rapidly evolving systems biology and machine learning approaches for analyzing high-throughput genetic, transcriptomic and epigenetic data, hold promise for identifying actionable biological processes and gene networks that underlie HAND. This review summarizes the current state of understanding of host genetic factors predisposing to HAND in light of past challenges and suggests some priorities for future research to advance the understanding and clinical management of HAND in the cART era.

Epidemiology of neurodegenerative diseases in sub-Saharan Africa: a systematic review

BACKGROUND

Sub-Saharan African (SSA) countries are experiencing rapid transitions with increased life expectancy. As a result the burden of age-related conditions such as neurodegenerative diseases might be increasing. We conducted a systematic review of published studies on common neurodegenerative diseases, and HIV-related neurocognitive impairment in SSA, in order to identify research gaps and inform prevention and control solutions.

METHODS

We searched MEDLINE via PubMed, 'Banque de Données de Santé Publique' and the database of the 'Institut d'Epidemiologie Neurologique et de Neurologie Tropicale' from inception to February 2013 for published original studies from SSA on neurodegenerative diseases and HIV-related neurocognitive impairment. Screening and data extraction were conducted by two investigators. Bibliographies and citations of eligible studies were investigated.

RESULTS

In all 144 publications reporting on dementia (n = 49 publications, mainly Alzheimer disease), Parkinsonism (PD, n = 20), HIV-related neurocognitive impairment (n = 47), Huntington disease (HD, n = 19), amyotrophic lateral sclerosis (ALS, n = 15), cerebellar degeneration (n = 4) and Lewy body dementia (n = 1). Of these studies, largely based on prevalent cases from retrospective data on urban populations, half originated from Nigeria and South Africa. The prevalence of dementia (Alzheimer disease) varied between <1% and 10.1% (0.7% and 5.6%) in population-based studies and from <1% to 47.8% in hospital-based studies. Incidence of dementia (Alzheimer disease) ranged from 8.7 to 21.8/1000/year (9.5 to 11.1), and major risk factors were advanced age and female sex. HIV-related neurocognitive impairment's prevalence (all from hospital-based studies) ranged from <1% to 80%. Population-based prevalence of PD and ALS varied from 10 to 235/100,000, and from 5 to 15/100,000 respectively while that for Huntington disease was 3.5/100,000. Equivalent figures for hospital based studies were the following: PD (0.41 to 7.2%), ALS (0.2 to 8.0/1000), and HD (0.2/100,000 to 46.0/100,000).

CONCLUSIONS

The body of literature on neurodegenerative disorders in SSA is large with regard to dementia and HIV-related neurocognitive disorders but limited for other neurodegenerative disorders. Shortcomings include few population-based studies, heterogeneous diagnostic criteria and uneven representation of countries on the continent. There are important knowledge gaps that need urgent action, in order to prepare the sub-continent for the anticipated local surge in neurodegenerative diseases.