Independent effects of HIV infection and cocaine dependence on neurocognitive impairment in a community sample living in the southern United States

Impaired extinction of cocaine seeking in HIV-infected mice is accompanied by peripheral and central immune dysregulation

Substance use disorders (SUDs) are highly comorbid with HIV infection, necessitating an understanding of the interactive effects of drug exposure and HIV. The relationship between HIV infection and cocaine use disorder is likely bidirectional, with cocaine use directly impacting immune function while HIV infection alters addiction-related behavior. To better characterize the neurobehavioral and immune consequences of HIV infection and cocaine exposure, this study utilizes a humanized mouse model to investigate the outcomes of HIV-1 infection on cocaine-related behaviors in a conditioned place preference (CPP) model, and the interactive effects of cocaine and HIV infection on peripheral and central nervous system inflammation. HIV infection selectively impairs cocaine CPP extinction without effecting reinstatement or cocaine seeking under conflict. Behavioral alterations are accompanied by immune changes in HIV infected mice, including increased prefrontal cortex astrocyte immunoreactivity and brain-region specific effects on microglia number and reactivity. Peripheral immune system changes are observed in human cytokines, including HIV-induced reductions in human TNFα, and cocaine and HIV interactions on GM-CSF levels. Together these data provide new insights into the unique neurobehavioral outcomes of HIV infection and cocaine exposure and how they interact to effect immune responses.

Longitudinal changes in neurocognitive performance related to drug use intensity in a sample of persons with and without HIV who use illicit stimulants

BACKGROUND

Illicit stimulant use remains a public health concern that has been associated with multiple adverse outcomes, including cognitive deficits. The effects of stimulant use on cognition may be particularly deleterious in persons with HIV. Stimulant use intensity may be an important factor in the magnitude of observed deficits over time.

METHODS

We completed neurocognitive testing in a sample of people who use stimulants with (n = 84) and without HIV (n = 123) at baseline and up to 4 follow-up time points over approximately 1 year. Participants reported on substance use at each visit, including frequency of use and stimulant dependence. Mixed effects models examined the relationship between stimulant-related factors and neurocognitive function over time.

RESULTS

Participants were mostly male (57%), African American (86%), and 47.41 years old on average. All participants actively used stimulants at enrollment and use remained prevalent throughout the follow-up period, with an average of ≥24 days of use in the past 90 days at all time points. Retention was excellent, with 86% completing all 4 follow-up assessments. Mixed effects models showed that stimulant dependence was associated with lower neurocognitive performance independent of HIV status (p = 0.002), whereas frequency of use had a greater negative impact on performance in participants with HIV compared to those without HIV (p = 0.045).

CONCLUSIONS

Our key finding is that stimulant-related factors are associated with neurocognitive performance over time, but in complex ways. These findings have important implications for harm reduction approaches, particularly those that target cognitive function.

Impaired extinction of cocaine seeking in HIV-infected mice is accompanied by peripheral and central immune dysregulation

Substance use disorders (SUDs) are highly comorbid with HIV infection, necessitating an understanding of the interactive effects of drug exposure and HIV. The relationship between HIV infection and cocaine use disorder is likely bidirectional, with cocaine use directly impacting immune function while HIV infection alters addiction-related behavior. To better characterize the neurobehavioral and immune consequences of HIV infection and cocaine exposure, this study utilized a humanized mouse model to investigate the outcomes of HIV-1 infection on cocaine-related behaviors in a conditioned place preference (CPP) model, and the interactive effects of cocaine and HIV infection on peripheral and central nervous system inflammation. HIV infection selectively impaired cocaine CPP extinction without effecting reinstatement or cocaine seeking under conflict were observed. Behavioral alterations were accompanied by immune changes in HIV infected mice, including increased prefrontal cortex astrocyte immunoreactivity and brain-region specific effects on microglia number and reactivity. Peripheral immune system changes were observed in both mouse and human cytokines, including HIV-induced reductions in mouse IL-1α and G-CSF and human TNFα, and cocaine induced alterations in mouse GM-CSF. Together these data provide new insights into the unique neurobehavioral outcomes of HIV infection and cocaine exposure and how they interact to effect immune responses.

Astrocytes: Role in pathogenesis and effect of commonly misused drugs in the HIV infected brain

The roles of astrocytes as reservoirs and producers of a subset of viral proteins in the HIV infected brain have been studied extensively as a key to understanding HIV-associated neurocognitive disorders (HAND). However, their comprehensive role in the context of intersecting substance use and neurocircuitry of the reward pathway and HAND has yet to be fully explained. Use of methamphetamines, cocaine, or opioids in the context of HIV infection have been shown to lead to a faster progression of HAND. Glutamatergic, dopaminergic, and GABAergic systems are implicated in the development of HAND-induced cognitive impairments. A thorough review of scientific literature exploring the variety of mechanisms in which these drugs exert their effects on the HIV brain and astrocytes has revealed marked areas of convergence in overexcitation leading to increased drug-seeking behavior, inflammation, apoptosis, and irreversible neurotoxicity. The present review investigates astrocytes, the neural pathways, and mechanisms of drug disruption that ultimately play a larger holistic role in terms of HIV progression and drug use. There are opportunities for future research, therapeutic intervention, and preventive strategies to diminish HAND in the subset population of patients with HIV and substance use disorder.

Impaired extinction of cocaine seeking in HIV-infected mice is accompanied by peripheral and central immune dysregulation

Substance use disorders (SUDs) are highly comorbid with HIV infection, necessitating an understanding of the interactive effects of drug exposure and HIV. The relationship between progressive HIV infection and cocaine use disorder is likely bidirectional, with cocaine use having direct effects on immune function while HIV infection can alter addiction-related behavior. To better characterized the neurobehavioral and immune consequences of HIV infection and cocaine exposure, this study utilized a humanized mouse model to investigate the outcomes of progressive HIV infection on cocaine-related behaviors in a cocaine conditioned place preference (CPP) model, and the interactive effects of cocaine and HIV infection on peripheral and central nervous system inflammation. HIV infection did not impact the formation of a cocaine CPP, but did result in resistance to extinction of the CPP. No effects of HIV on yohimbine-primed reinstatement or cocaine seeking under conflict were observed. These behavioral alterations were accompanied by immune changes in HIV infected mice, including increased prefrontal cortex astrocyte immunoreactivity and brain-region specific effects on microglia number and reactivity. Peripheral immune system changes were observed in both mouse and human markers. Among other targets, this included HIV-induced reductions in mouse IL-1α and G-CSF and human TNFα and cocaine-induced alterations in human TNFα and mouse GM-CSF such that cocaine exposure increases both cytokines only in the absence of HIV infection. Together these data provide new insights into the unique neurobehavioral processes underlying HIV infection and cocaine use disorders, and further how they interact to effect immune responses.

HIV viremia contributes to neurocognitive impairments in persons who use cocaine

Persons with HIV (PWH) who use illicit drugs are at elevated risk for neurocognitive impairment (NCI). This study investigated the effects of HIV disease and HIV viremia on NCI among adults who use cocaine. PWH who were not virologically suppressed showed greater global deficits compared to participants with HIV viral suppression and HIV-negative participants, but no differences emerged between the latter two groups. These findings highlight the adverse effects of poorly controlled HIV disease on NCI, beyond the independent effects of cocaine on cognition, and underscore the importance of strengthening the HIV care continuum for persons who use cocaine.

Cortico-striatal networking deficits associated with advanced HIV disease and cocaine use

Cocaine use is disproportionately prevalent in people with HIV (PWH) and is known to potentiate HIV neuropathogenesis. As both HIV and cocaine have well-documented cortico-striatal effects, PWH who use cocaine and have a history of immunosuppression may exhibit greater FC deficits compared to PWH without these conditions. However, research investigating the legacy effects of HIV immunosuppression (i.e., a history of AIDS) on cortico-striatal functional connectivity (FC) in adults with and without cocaine use is sparse. Resting-state functional magnetic resonance imaging (fMRI) and neuropsychological assessment data from 273 adults were analyzed to examine FC in relation to HIV disease: HIV-negative (n = 104), HIV-positive with nadir CD4 ≥ 200 (n = 96), HIV-positive with nadir CD4 < 200 (AIDS; n = 73), and cocaine use (83 COC and 190 NON). Using independent component analysis/dual regression, FC was assessed between the basal ganglia network (BGN) and five cortical networks: dorsal attention network (DAN), default mode network, left executive network, right executive network, and salience network. There were significant interaction effects such that AIDS-related BGN-DAN FC deficits emerged in COC but not in NON participants. Independent of HIV, cocaine effects emerged in FC between the BGN and executive networks. Disruption of BGN-DAN FC in AIDS/COC participants is consistent with cocaine potentiation of neuro-inflammation and may be indicative of legacy HIV immunosuppressive effects. The current study bolsters previous findings linking HIV and cocaine use with cortico-striatal networking deficits. Future research should consider the effects of the duration of HIV immunosuppression and early treatment initiation.

Additive cortical gray matter deficits in people living with HIV who use cocaine

Cocaine use, which is disproportionately common in people living with HIV (PWH), is known to have neurotoxic effects that may exacerbate HIV neuropathogenesis. While both cocaine use and HIV disease are independently associated with deficits in gray matter (GM) volume, the additive effect of cocaine use to HIV disease on GM volume has not been explored. Here, we investigated subcortical and cortical brain volume differences between four groups of individuals with and without HIV disease and/or cocaine use. Participants also completed a comprehensive neuropsychological testing battery, and HIV disease characteristics were recorded. Within subcortical regions, cocaine use was independently associated with higher volume in the dorsal striatum and pallidum, while HIV disease was associated with lower volume in the nucleus accumbens and thalamus. For cortical regions, there was an additive effect of cocaine use on HIV disease in parietal and occipital lobe volume with PWH who used cocaine displaying the lowest GM volume. Within regions that differed between groups, higher neurocognitive function was positively associated with thalamic, nucleus accumbens, dorsal striatum, and occipital lobe volume. For regions that showed a significant main effect of HIV disease, lower nadir CD4 + T cell count was associated with lower nucleus accumbens and occipital lobe volume. Lower current CD4 + T cell count was associated with lower occipital lobe volume. These results suggest that PWH who use cocaine are at greater risk for cortical atrophy than cocaine use or HIV disease alone.

Neuroimaging and immunological features of neurocognitive function related to substance use in people with HIV

This study sought to identify neuroimaging and immunological factors associated with substance use and that contribute to neurocognitive impairment (NCI) in people with HIV (PWH). We performed cross-sectional immunological phenotyping, neuroimaging, and neurocognitive testing on virally suppressed PWH in four substance groups: cocaine only users (COC), marijuana only users (MJ), dual users (Dual), and Non-users. Participants completed substance use assessments, multimodal MRI brain scan, neuropsychological testing, and blood and CSF sampling. We employed a two-stage analysis of 305 possible biomarkers of cognitive function associated with substance use. Feature reduction (Kruskal Wallis p-value < 0.05) identified 53 biomarkers associated with substance use (22 MRI and 31 immunological) for model inclusion along with clinical and demographic variables. We employed eXtreme Gradient Boosting (XGBoost) with these markers to predict cognitive function (global T-score). SHapley Additive exPlanations (SHAP) values were calculated to rank features for impact on model output and NCI. Participants were 110 PWH with sustained HIV viral suppression (33 MJ, 12 COC, 22 Dual, and 43 Non-users). The ten highest ranking biomarkers for predicting global T-score were 4 neuroimaging biomarkers including functional connectivity, gray matter volume, and white matter integrity; 5 soluble biomarkers (plasma glycine, alanine, lyso-phosphatidylcholine (lysoPC) aC17.0, hydroxy-sphingomyelin (SM.OH) C14.1, and phosphatidylcholinediacyl (PC aa) C28.1); and 1 clinical variable (nadir CD4 count). The results of our machine learning model suggest that substance use may indirectly contribute to NCI in PWH through both metabolomic and neuropathological mechanisms.

Development of a Nomogram-Based Tool to Predict Neurocognitive Impairment Among HIV-positive Charter Participants

Background:

Despite the widespread use of combination antiretroviral therapy (cART), HIV-associated neurocognitive impairment (NCI) persists in people living with HIV (PLWH). Studies have generated inconsistent results regarding etiological factors for NCI in PLWH. Furthermore, a user-friendly and readily available predictive tool is desirable in clinical practice to screen PLWH for NCI.

Objective:

This study aimed to identify factors associated with NCI using a large and diverse sample of PLWH and build a nomogram based on demographic, clinical, and behavioral variables.

Methods:

We performed Bayesian network analysis using a supervised learning technique with the Markov Blanket (MB) algorithm. Logistic regression was also conducted to obtain the adjusted regression coefficients to construct the nomogram.

Results:

Among 1,307 participants, 21.6% were neurocognitively impaired. During the MB analysis, age provided the highest amount of mutual information (0.0333). Logistic regression also showed that old age (>50 vs. ≤50 years) had the strongest association (OR=2.77, 95% CI=1.99-3.85) with NCI. The highest possible points on the nomogram were 626, translated to a nomogram-predicted probability of NCI to be approximately 0.95. The receiver operating characteristic (ROC) curve's concordance index was 0.75, and the nomogram's calibration plot exhibited an excellent agreement between observed and predicted probabilities.

Conclusion:

The nomogram used variables that can be easily measured in clinical settings and, thus, easy to implement within a clinic or web-interface platform. The nomogram may help clinicians screen for patients with a high probability of having NCI and thus needing a comprehensive neurocognitive assessment for early diagnosis and appropriate management.

Web-Based Cognitive Training to Improve Working Memory in Persons with Co-Occurring HIV Infection and Cocaine Use Disorder: Outcomes from a Randomized Controlled Trial

Neurocognitive impairment (NCI) remains a persistent complication of HIV disease that nearly half of persons with HIV experience, and rates are even higher in persons who use substances such as cocaine. Cognitive training is a promising intervention for HIV-associated NCI. In this randomized controlled trial, we examined the feasibility and effectiveness of a web-based cognitive training program to improve working memory in a sample of 58 persons with HIV and cocaine use disorder. Participants were randomly assigned to either the experimental working memory training arm or the attention control training arm and completed up to 48 daily sessions over 10 weeks. Overall, treatment completion (74%) and retention rates (97%) were high, and participant feedback indicated the intervention was acceptable. Our results show that the intervention successfully reduced working memory deficits in the experimental arm relative to the control arm. Our findings support both the feasibility and effectiveness of cognitive training in this population.

Food Insecurity and Cognitive Impairment in the Miami Adult Studies on HIV (MASH) Cohort

BACKGROUND

Food insecurity is a social determinant of health associated with cognitive impairments in older adults and people living with HIV (PLWH). Few studies have examined this relation longitudinally, and no studies have explored how the frequency of food insecurity over time may impact cognitive impairment.

OBJECTIVE

This study aimed to examine the impact of food insecurity on cognitive impairment over a 2-y follow-up period in a cohort of people living with and without HIV.

METHODS

This was a 2-y longitudinal analysis of primarily economically disadvantaged, middle-aged, Black, and Hispanic participants from the Miami Adult Studies on HIV (MASH) cohort. Food insecurity was assessed with the USDA Household Food Security Module at baseline and 12- and 24-mo follow-ups. Food insecurity in all 3 assessments was considered persistent food insecurity. Cognitive impairment was assessed with the Mini-Mental State Examination. Statistical analyses consisted of logistic regressions.

RESULTS

A total of 394 participants (247 HIV positive) with 2-y follow-up data were included in this analysis. At baseline, 104 (26.4%) were food-insecure and 58 (14.7%) had cognitive impairment. Very low food security was associated with cognitive impairment at baseline (OR: 3.23; 95% CI: 1.08, 9.65). PLWH not virally suppressed had higher risk for cognitive impairment compared with HIV-uninfected participants (OR: 2.87; 95% CI: 1.15, 7.18). Additionally, baseline food insecurity (OR: 2.28; 95% CI: 1.08, 4.81) and the frequency of food insecurity over time (OR: 1.50 per year; 95% CI: 1.08, 2.10), particularly persistent food insecurity (OR: 3.69; 95% CI: 1.15, 11.83), were associated with cognitive impairment at 2-y follow-up; the results were consistent after excluding cognitively impaired participants at baseline.

CONCLUSIONS

Food insecurity is a significant risk factor for cognitive impairment, particularly among individuals who experience food insecurity frequently or persistently. Screening for food insecurity and interventions to secure access to sufficient, nutritious foods may help delay cognitive decline among socioeconomically disadvantaged individuals.

HIV Neuropathogenesis in the Presence of a Disrupted Dopamine System

Antiretroviral therapy (ART) has transformed HIV into a chronic condition, lengthening and improving the lives of individuals living with this virus. Despite successful suppression of HIV replication, people living with HIV (PLWH) are susceptible to a growing number of comorbidities, including neuroHIV that results from infection of the central nervous system (CNS). Alterations in the dopaminergic system have long been associated with HIV infection of the CNS. Studies indicate that changes in dopamine concentrations not only alter neurotransmission, but also significantly impact the function of immune cells, contributing to neuroinflammation and neuronal dysfunction. Monocytes/macrophages, which are a major target for HIV in the CNS, are responsive to dopamine. Therefore, defining more precisely the mechanisms by which dopamine acts on these cells, and the changes in cellular function elicited by this neurotransmitter are necessary to develop therapeutic strategies to treat neuroHIV. This is especially important for vulnerable populations of PLWH with chemically altered dopamine concentrations, such as individuals with substance use disorder (SUD), or aging individuals using dopamine-altering medications. The specific neuropathologic and neurocognitive consequences of increased CNS dopamine remain unclear. This is due to the complex nature of HIV neuropathogenesis, and logistical and technical challenges that contribute to inconsistencies among cohort studies, animal models and in vitro studies, as well as lack of demographic data and access to human CNS samples and cells. This review summarizes current understanding of the impact of dopamine on HIV neuropathogenesis, and proposes new experimental approaches to examine the role of dopamine in CNS HIV infection. Graphical abstract HIV Neuropathogenesis in the Presence of a Disrupted Dopamine System. Both substance abuse disorders and the use of dopaminergic medications for age-related diseases are associated with changes in CNS dopamine concentrations and dopaminergic neurotransmission. These changes can lead to aberrant immune function, particularly in myeloid cells, which contributes to the neuroinflammation, neuropathology and dysfunctional neurotransmission observed in dopamine-rich regions in HIV+ individuals. These changes, which are seen despite the use antiretroviral therapy (ART), in turn lead to further dysregulation of the dopamine system. Thus, in individuals with elevated dopamine, the bi-directional interaction between aberrant dopaminergic neurotransmission and HIV infection creates a feedback loop contributing to HIV associated neurocognitive dysfunction and neuroHIV. However, the distinct contributions and interactions made by HIV infection, inflammatory mediators, ART, drugs of abuse, and age-related therapeutics are poorly understood. Defining more precisely the mechanisms by which these factors influence the development of neurological disease is critical to addressing the continued presence of neuroHIV in vulnerable populations, such as HIV-infected older adults or drug abusers. Due to the complexity of this system, understanding these effects will require a combination of novel experimental modalities in the context of ART. These will include more rigorous epidemiological studies, relevant animal models, and in vitro cellular and molecular mechanistic analysis.

The Role of Mental Health Conditions in the Diagnosis of Neurocognitive Impairment in People Living with HIV

The aims of the present study were to evaluate the prevalence of undiagnosed mental health conditions (UMHC) in people living with HIV (PLWHIV) on antiretroviral treatment and with long-term suppressed HIV viremia, and its association with neurocognitive impairment (NCI). A cross-sectional observational study on HIV subjects, ≥18 years old, on stable antiretroviral treatment and with HIV viral load <50 copies/mL was carried out. Patients with known comorbidities, substances abuse, anxiety or depression were excluded. UMHC were evaluated by the Millon Clinical Multiaxial Inventory-III and NCI by Frascati criteria. The association between NCI and sociodemographic, clinical HIV variables and mental health conditions was analyzed. Further, the relationship between mental health conditions scores and NCI diagnosis was evaluated. Eighty patients were included, 37.5% had at least one undiagnosed mental health condition, and 26.3% had NCI. The most frequent mental health conditions were: anxiety (21.3%); bipolar disorder (11.3%); and substance dependence (8.8%). Only longer time since HIV diagnosis (p = 0.030) and at least one mental health condition diagnosis (p = 0.002) showed an association with NCI. Participants with NCI presented higher scores in anxiety, alcohol dependence and post-traumatic stress. Undiagnosed mental health conditions are frequent in PLWHIV. These disorders cannot be identified by HIV clinicians or basic screening questionnaires, and they are not usually self-reported by patients. UMHC could act as confounders in the evaluation of NCI.

The impact of substance abuse on HIV-mediated neuropathogenesis in the current ART era

Approximately 37 million people worldwide are infected with human immunodeficiency virus (HIV). One highly significant complication of HIV infection is the development of HIV-associated neurocognitive disorders (HAND) in 15-55% of people living with HIV (PLWH), that persists even in the antiretroviral therapy (ART) era. The entry of HIV into the central nervous system (CNS) occurs within 4-8 days after peripheral infection. This establishes viral reservoirs that may persist even in the presence of ART. Once in the CNS, HIV infects resident macrophages, microglia, and at low levels, astrocytes. In response to chronic infection and cell activation within the CNS, viral proteins, inflammatory mediators, and host and viral neurotoxic factors produced over extended periods of time result in neuronal injury and loss, cognitive deficits and HAND. Substance abuse is a common comorbidity in PLWH and has been shown to increase neuroinflammation and cognitive disorders. Additionally, it has been associated with poor ART adherence, and increased viral load in the cerebrospinal fluid (CSF), that may also contribute to increased neuroinflammation and neuronal injury. Studies have examined mechanisms that contribute to neuroinflammation and neuronal damage in PLWH, and how substances of abuse exacerbate these effects. This review will focus on how substances of abuse, with an emphasis on methamphetamine (meth), cocaine, and opioids, impact blood brain barrier (BBB) integrity and transmigration of HIV-infected and uninfected monocytes across the BBB, as well as their effects on monocytes/macrophages, microglia, and astrocytes within the CNS. We will also address how these substances of abuse may contribute to HIV-mediated neuropathogenesis in the context of suppressive ART. Additionally, we will review the effects of extracellular dopamine, a neurotransmitter that is increased in the CNS by substances of abuse, on HIV neuropathogenesis and how this may contribute to neuroinflammation, neuronal insult, and HAND in PLWH with active substance use. Lastly, we will discuss some potential therapies to limit CNS inflammation and damage in HIV-infected substance abusers.

Recent cocaine use and memory impairment in HIV

Both Human Immunodeficiency Virus (HIV) and cocaine use have been associated with impairment in neuropsychological functioning. The high comorbidity between HIV and cocaine use highlights the importance of ascertaining whether there is a compounding effect of cocaine use in individuals with HIV. Among neuropsychological domains impacted by HIV, verbal memory deficits have received substantial attention partly because they have been associated with declines in functional status in HIV positive individuals. We collected California Verbal Learning Test-II data from HIV participants who met lifetime diagnostic criteria of cocaine abuse and/or dependence (HIV/CocDx+, N = 80 & HIV/CocDx-, N = 30, respectively) and those with and without recent cocaine use, which was confirmed by toxicology analysis (HIV/Coc+, N = 56 & HIV/Coc-, N = 57, respectively). The Item Specific Deficit Approach (ISDA) was employed to determine any additional cocaine-associated deficits in encoding, consolidation, and retrieval, which attempts to control for potential confounding factors of memory such as attention. Using conventional methods of evaluating memory profiles, we found that the HIV/Coc + group demonstrated worse learning, immediate and delayed free recall, and recognition in contrast to the HIV/Coc - group; although using the ISDA, we found that encoding was the only significant difference between HIV/Coc + and HIV/Coc-participant, with HIV/Coc - performing better. Our data suggest that for individuals with HIV, cocaine use is associated with a temporary decline in verbal memory, is characterized by greater encoding deficits, and these effects may reduce with abstinence. Clinically, our findings suggest that reduced encoding is the likely contributor to verbal memory decline in HIV/Coc + and these effects are partially reversible-at least to the level of their HIV/Coc - counterparts.

Sexual Orientation, Religious Coping, and Drug Use in a Sample of HIV-Infected African-American Men Living in the Southern USA

Religiosity and spirituality are associated with reduced drug use in the general population, but it is unclear whether this relationship generalizes to sexual minorities. This study investigated the relationship between religious coping, drug use, and sexual orientation in a sample of HIV-infected African-American men (40 heterosexuals; 64 sexual minorities). Most participants (76%) reported being "moderately" or "very" religious. We found no main effect of religious coping or sexual orientation on frequency of drug use. However, there was an interaction between positive religious coping and sexual orientation. Among heterosexuals, positive religious coping was inversely associated with frequency of drug use. However, this relationship was not significant among sexual minorities. Findings suggest HIV-infected African-American sexual minorities living in the South may need additional coping resources to decrease vulnerability to drug use.

Neurologic Complications of Human Immunodeficiency Virus Infection

PURPOSE OF REVIEW

Widespread use of antiretroviral therapy (ART) has led to near-normal life expectancy in people with human immunodeficiency virus (HIV) infection. However, neurologic complications of HIV remain common; can affect any part of the neuraxis; and are due to direct effects of the virus, immunosuppression because of untreated HIV infection, aberrant immune responses in the setting of ART initiation, and ART toxicities.

RECENT FINDINGS

HIV-associated neurocognitive disorder (HAND) remains one of the most common neurologic complications of HIV encountered today, but milder forms predominate in people on ART. No specific treatments for HAND exist, but small trials and epidemiologic evidence suggest paroxetine, intranasal insulin, and maraviroc may have utility in its treatment; further trials of these agents are ongoing. Widespread ART use has decreased the incidence of central nervous system opportunistic infections, but prognosis often remains poor in those who develop opportunistic infections. High-titer positive serum cryptococcal antigen is strongly predictive of cryptococcal meningitis and provides a tool to enhance diagnosis in areas with limited resources. HIV is an independent risk factor for stroke, and accelerated aging associated with HIV infection results in neurologic diseases of older age occurring at much younger ages in individuals infected with HIV. Ongoing HIV replication in the CSF despite peripheral virologic suppression may contribute to the development of HAND and may not improve despite adjusting the ART regimen to increase central nervous system penetrance.

SUMMARY

Neurologists are likely to encounter patients infected with HIV in clinical practice. This article reviews the presentation, diagnosis, and management of the most common neurologic conditions associated with HIV infection and ART.

Rationale and design of an integrated bio-behavioral approach to improve adherence to pre-exposure prophylaxis and HIV risk reduction among opioid-dependent people who use drugs: The CHRP-BB study

BACKGROUND

Few primary HIV prevention strategies have successfully integrated both behavioral and biomedical components, with modest HIV risk reduction outcomes among opioid-dependent people who use drugs (PWUD). In response to this unmet need, we developed a brief, bio-behavioral intervention to simultaneously promote PrEP adherence and reduce HIV risk among opioid-dependent PWUD.

METHODS

Using a Hybrid Type I implementation science design, we will examine the efficacy of the integrated bio-behavioral, Community-friendly Health Recovery Program (CHRP-BB) compared to a time-and-attention matched control condition among HIV-negative, opioid-dependent PWUD who are prescribed PrEP and enrolled in a methadone maintenance program (MMP) using a randomized controlled trial (RCT). Participants are assessed at baseline, immediately post-intervention (8 weeks) and follow-ups at weeks 20, 32, and 44 post-intervention. The primary outcome is biomedical (PrEP adherence), with secondary outcomes including behavioral (self-reported drug- and sex-related HIV risk behaviors), ongoing drug use (confirmed with urine drug testing), and related domains of the theoretical information-motivation-behavioral skills (IMB) model of behavior change related to PrEP adherence and HIV-transmission-risk reduction. Additionally, we will conduct a process evaluation of delivery/implementation of the intervention to collect valuable information to be used in future implementation.

CONCLUSIONS

This study will be among the first prospective trial to test an integrated bio-behavioral intervention to improve adherence to PrEP and HIV risk reduction among opioid-dependent PWUD.

Reward and executive control network resting-state functional connectivity is associated with impulsivity during reward-based decision making for cocaine users

BACKGROUND

Cocaine addiction is related to impulsive decision making that is mediated by brain circuitry involved in reward processing and executive functions, such as cognitive control and attentional salience. Resting-state functional connectivity between reward and executive control circuitry is altered among cocaine users, with concomitant deficits in impulsivity and learning. Prior research has examined how select brain regions interact to influence impulsive decision making for drug users; however, research examining interactions between large-scale brain networks and impulsive behavior is limited.

METHODS

The current study compared reward and executive control network resting-state functional connectivity and its relationship to impulsive decision making between cocaine users (n = 37) and non-cocaine using control participants (n = 35). Participants completed computerized decision-making tasks and a separate resting-state functional magnetic resonance imaging scan. Data underwent independent component, dual regression, and linear regression moderation analyses.

RESULTS

Higher impulsivity on the Balloon Analogue Risk Task (BART) was associated with inverse resting-state connectivity between the left cognitive control and subgenual anterior cingulate extended reward networks for cocaine users, while the opposite was found for controls. Less impulsivity on the monetary choice questionnaire was associated with stronger positive resting-state connectivity between the attentional salience and striatal core reward networks for controls, while cocaine users showed no association between impulsivity and resting-state connectivity of these networks.

CONCLUSIONS

Cocaine users show aberrant associations between reward-executive control resting-state network coupling and impulsive decision making. The findings support the conclusion that an imbalance between reward and executive control circuitry contributes to impulsivity in drug use.

Inter-trial variability in brain activity as an indicator of synergistic effects of HIV-1 and drug abuse

BACKGROUND

The objective of this investigation was to detect evidence of the synergism in the effects of HIV-1 and drug abuse on brain function that has been hypothesized but rarely shown. The investigation incorporated several noteworthy improvements in the approach. It used urine toxicology tests to exclude participants complicated by recent methadone use and illicit drug use. Also, it defined drug abuse on a scale that considered symptom severity. Most importantly, it examined inter-trial variability in brain activity as a potentially more sensitive indicator of group differences and functional impairment than the across-trial average.

METHODS

173 participants were assigned to groups defined by their HIV-1 serostatus and Drug Abuse Screening Test score (DAST < vs. > = 6). They completed a simple letter discrimination task including rare target and rare nontarget stimuli. Event-related electroencephalographic responses and key press responses were measured on each trial. During a separate assessment, posturographic measures were recorded.

RESULTS

The inter-trial standard deviation of P300-like activity was superior to the mean amplitude of this activity in differentiating the groups. Unlike the mean, it revealed synergistic statistical effects of HIV and drug abuse. It also correlated significantly with static ataxia.

CONCLUSIONS

Inter-trial variability in P300-like activity is a useful marker for detecting subtle and episodic disruptions in brain function. It demonstrates greater sensitivity than the mean amplitude for detecting differences across groups. Also, as a putative indicator of a disruption in the attentional monitoring of behavior, it predicts subtle impairments in gross motor function.

Integrated Bio-behavioral Approach to Improve Adherence to Pre-exposure Prophylaxis and Reduce HIV Risk in People Who Use Drugs: A Pilot Feasibility Study

This study reports the feasibility, acceptability, and preliminary efficacy of the bio-behavioral community-friendly health recovery program-an integrated, HIV prevention intervention to improve pre-exposure prophylaxis (PrEP) adherence and HIV-risk reduction behaviors among high-risk people who use drugs. We used a within-subjects, pretest-posttest follow-up design to recruit participants, who were HIV-uninfected, methadone-maintained and reported HIV-risk behaviors and had initiated PrEP (n = 40; males: 55%). Participants were assessed at baseline (T₀), immediately post-intervention (4 weeks: T₄) and 4 weeks post-intervention (T₈). Immediately after completing the four weekly intervention groups, participants underwent a post-intervention assessment including in-depth qualitative interviews. Feasibility was high, assessed by participant willingness to enroll (90.1%) and retention (95%). Results showed that participants were highly satisfied and perceived the intervention as valuable and acceptable [mean: 81.3 (range 0-100)]. Significant enhancements in self-reported PrEP adherence [F(2,74) = 7.500, p = 0.001] and PrEP-related knowledge [F(2,74) = 3.828, p = 0.026] were observed. Drug-related (e.g., injection of drugs, sharing of injection equipment) and sex-related (e.g., number of sexual partners, condomless sex) risk behaviors were reduced, while information, motivation, and behavioral skills (IMB) constructs increased. The results support feasibility and high acceptability and support further examination of the efficacy of this combination bio-behavioral intervention in a prospective clinical trial.

The role of catecholamines in HIV neuropathogenesis

The success of anti-retroviral therapy has improved the quality of life and lifespan of HIV + individuals, transforming HIV infection into a chronic condition. These improvements have come with a cost, as chronic HIV infection and long-term therapy have resulted in the emergence of a number of new pathologies. This includes a variety of the neuropathological and neurocognitive effects collectively known as HIVassociated neurocognitive disorders (HAND) or NeuroHIV. These effects persist even in the absence of viral replication, suggesting that they are mediated the long-term changes in the CNS induced by HIV infection rather than by active replication. Among these effects are significant changes in catecholaminergic neurotransmission, especially in dopaminergic brain regions. In HIV-infected individuals not treated with ARV show prominent neuropathology is common in dopamine-rich brain regions and altered autonomic nervous system activity. Even infected individuals on therapy, there is significant dopaminergic neuropathology, and elevated stress and norepinephrine levels correlate with a decreased effectiveness of antiretroviral drugs. As catecholamines function as immunomodulatory factors, the resultant dysregulation of catecholaminergic tone could substantially alter the development of HIVassociated neuroinflammation and neuropathology. In this review, we discuss the role of catecholamines in the etiology of HIV neuropathogenesis. Providing a comprehensive examination of what is known about these molecules in the context of HIV-associated disease demonstrates the importance of further studies in this area, and may open the door to new therapeutic strategies that specifically ameliorate the effects of catecholaminergic dysregulation on NeuroHIV.

Adolescent brain cognitive development (ABCD) study: Overview of substance use assessment methods

One of the objectives of the Adolescent Brain Cognitive Development (ABCD) Study (https://abcdstudy.org/) is to establish a national longitudinal cohort of 9 and 10 year olds that will be followed for 10 years in order to prospectively study the risk and protective factors influencing substance use and its consequences, examine the impact of substance use on neurocognitive, health and psychosocial outcomes, and to understand the relationship between substance use and psychopathology. This article provides an overview of the ABCD Study Substance Use Workgroup, provides the goals for the workgroup, rationale for the substance use battery, and includes details on the substance use module methods and measurement tools used during baseline, 6-month and 1-year follow-up assessment time-points. Prospective, longitudinal assessment of these substance use domains over a period of ten years in a nationwide sample of youth presents an unprecedented opportunity to further understand the timing and interactive relationships between substance use and neurocognitive, health, and psychopathology outcomes in youth living in the United States.

Examining the Acceptability of mHealth Technology in HIV Prevention Among High-Risk Drug Users in Treatment

Despite promising trends of the efficacy of mobile health (mHealth) based strategies to a broad range of health conditions, very few if any studies have been done in terms of the examining the use of mHealth in HIV prevention efforts among people who use drugs in treatment. Thus, the goal of this study was to gain insight into the real-world acceptance of mHealth approaches among high-risk people who use drugs in treatment. A convenience sample of 400 HIV-negative drug users, who reported drug- and/or sex-related risk behaviors, were recruited from a methadone clinic in New Haven, Connecticut. Participants completed standardized assessments of drug- and sex-related risk behaviors, neurocognitive impairment (NCI), and measures of communication technology access and utilization, and mHealth acceptance. We found a high prevalence of current ownership and use of mobile technologies, such as cell phone (91.5%) including smartphone (63.5%). Participants used mobile technologies to communicate mostly through phone calls (M = 4.25, SD = 1.24), followed by text messages (M = 4.21, SD = 1.29). Participants expressed interest in using mHealth for medication reminders (72.3%), receive information about HIV (65.8%), and to assess drug-related (72.3%) and sex-related behaviors (64.8%). Furthermore, participants who were neurocognitively impaired were more likely to use cell phone without internet and show considerable interest in using mHealth as compared to those without NCI. The findings from this study provide empirical evidence that mHealth-based programs, specifically cell phone text messaging-based health programs, may be acceptable to this high-risk population.

Neuropsychological comparisons of cocaine versus methamphetamine users: A research synthesis and meta-analysis

BACKGROUND

Previous meta-analytical research examining cocaine and methamphetamine separately suggests potentially different neuropsychological profiles associated with each drug. In addition, neuroimaging studies point to distinct structural changes that might underlie differences in neuropsychological functioning.

OBJECTIVES

This meta-analysis compared the effect sizes identified in cocaine versus methamphetamine studies across 15 neuropsychological domains.

METHOD

Investigators searched and coded the literature examining the neuropsychological deficits associated with a history of either cocaine or methamphetamine use. A total of 54 cocaine and 41 methamphetamine studies were selected, yielding sample sizes of 1,718 and 1,297, respectively. Moderator analyses were conducted to compare the two drugs across each cognitive domain.

RESULTS

Data revealed significant differences between the two drugs. Specifically, studies of cocaine showed significantly larger effect-size estimates (i.e., poorer performance) in verbal working memory when compared to methamphetamine. Further, when compared to cocaine, methamphetamine studies demonstrated significantly larger effect sizes in delayed contextual verbal memory and delayed visual memory.

CONCLUSION

Overall, cocaine and methamphetamine users share similar neuropsychological profiles. However, cocaine appears to be more associated with working memory impairments, which are typically frontally mediated, while methamphetamine appears to be more associated with memory impairments that are linked with temporal and parietal lobe dysfunction.

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.

Longitudinal Modeling of Depressive Trajectories Among HIV-Infected Men Using Cocaine

Cocaine use is prevalent among HIV-infected individuals. While cross-sectional studies suggest that cocaine users may be at increased risk for depression, long-term effects of cocaine on depressive symptoms remain unclear. This is a longitudinal study of 341 HIV-infected and uninfected men (135 cocaine users and 206 controls) ages 30-60 enrolled in the Multicenter AIDS Cohort Study during 1996-2009. The median baseline age was 41; 73% were African-American. In mixed-effects models over a median of 4.8 years of observation, cocaine use was associated with higher depressive symptoms independent of age, education level, and smoking (n = 288; p = 0.02); HIV infection modified this association (p = 0.03). Latent class mixed models were used to empirically identify distinct depressive trajectories (n = 160). In adjusted models, cocaine use was associated with threefold increased odds of membership in the class with persistent high depressive symptoms (95% confidence interval (CI) 1.38-6.69) and eightfold increased odds (95% CI (2.73-25.83) when tested among HIV-infected subjects only. Cocaine use is a risk factor for chronic depressive symptoms, particularly among HIV-infected men, highlighting the importance of integrating mental health and substance use treatments to address barriers to well-being and successful HIV-care.

Developing an Integrated, Brief Biobehavioral HIV Prevention Intervention for High-Risk Drug Users in Treatment: The Process and Outcome of Formative Research

To date, HIV prevention efforts have largely relied on singular strategies (e.g., behavioral or biomedical approaches alone) with modest HIV risk-reduction outcomes for people who use drugs (PWUD), many of whom experience a wide range of neurocognitive impairments (NCI). We report on the process and outcome of our formative research aimed at developing an integrated biobehavioral approach that incorporates innovative strategies to address the HIV prevention and cognitive needs of high-risk PWUD in drug treatment. Our formative work involved first adapting an evidence-based behavioral intervention-guided by the Assessment-Decision-Administration-Production-Topical experts-Integration-Training-Testing model-and then combining the behavioral intervention with an evidence-based biomedical intervention for implementation among the target population. This process involved eliciting data through structured focus groups (FGs) with key stakeholders-members of the target population (n = 20) and treatment providers (n = 10). Analysis of FG data followed a thematic analysis approach utilizing several qualitative data analysis techniques, including inductive analysis and cross-case analysis. Based on all information, we integrated the adapted community-friendly health recovery program-a brief evidence-based HIV prevention behavioral intervention-with the evidence-based biomedical component [i.e., preexposure prophylaxis (PrEP)], an approach that incorporates innovative strategies to accommodate individuals with NCI. This combination approach-now called the biobehavioral community-friendly health recovery program-is designed to address HIV-related risk behaviors and PrEP uptake and adherence as experienced by many PWUD in treatment. This study provides a complete example of the process of selecting, adapting, and integrating the evidence-based interventions-taking into account both empirical evidence and input from target population members and target organization stakeholders. The resultant brief evidence-based biobehavioral approach could significantly advance primary prevention science by cost-effectively optimizing PrEP adherence and HIV risk reduction within common drug treatment settings.

Food Insecurity Is Associated with Cognitive Deficits Among HIV-Positive, But Not HIV-Negative, Individuals in a United States Sample

People living with HIV/AIDS (PLWHA) in the United States (US) have disproportionately high rates of food insecurity (FI). In the general population, FI has been associated with cognitive impairment among older adults and may exacerbate HIV-associated neurocognitive disorders. The current study assessed the effects of FI and HIV infection on the neuropsychological performance of 61 HIV-positive and 36 HIV-negative adults in the US. While the main effects were minimal, the interactive effects revealed that FI was related to deficits in speed of information processing, learning, memory, motor function, and overall cognitive impairment for the HIV-positive group, but not the HIV-negative group. The interactive effects remained after controlling for relevant sociodemographic characteristics. Although bidirectional associations cannot be ruled out in a cross-sectional study, the results suggest that FI may contribute to cognitive impairment among HIV-positive adults in the US. Given the high rates of socioeconomic disadvantage among PLWHA in the US, addressing FI as part of routine clinical care may be warranted.

Cocaine dependence does not contribute substantially to white matter abnormalities in HIV infection

This study investigated the association of HIV infection and cocaine dependence with cerebral white matter integrity using diffusion tensor imaging (DTI). One hundred thirty-five participants stratified by HIV and cocaine status (26 HIV+/COC+, 37 HIV+/COC-, 37 HIV-/COC+, and 35 HIV-/COC-) completed a comprehensive substance abuse assessment, neuropsychological testing, and MRI with DTI. Among HIV+ participants, all were receiving HIV care and 46% had an AIDS diagnosis. All COC+ participants were current users and met criteria for cocaine use disorder. We used tract-based spatial statistics (TBSS) to assess the relation of HIV and cocaine to fractional anisotropy (FA) and mean diffusivity (MD). In whole-brain analyses, HIV+ participants had significantly reduced FA and increased MD compared to HIV- participants. The relation of HIV and FA was widespread throughout the brain, whereas the HIV-related MD effects were restricted to the corpus callosum and thalamus. There were no significant cocaine or HIV-by-cocaine effects. These DTI metrics correlated significantly with duration of HIV disease, nadir CD4+ cell count, and AIDS diagnosis, as well as some measures of neuropsychological functioning. These results suggest that HIV is related to white matter integrity throughout the brain, and that HIV-related effects are more pronounced with increasing duration of infection and greater immune compromise. We found no evidence for independent effects of cocaine dependence on white matter integrity, and cocaine dependence did not appear to exacerbate the effects of HIV.

Dopamine Increases CD14+CD16+ Monocyte Transmigration across the Blood Brain Barrier: Implications for Substance Abuse and HIV Neuropathogenesis

In human immunodeficiency virus-1 (HIV) infected individuals, substance abuse may accelerate the development and/or increase the severity of HIV associated neurocognitive disorders (HAND). It is proposed that CD14⁺CD16⁺ monocytes mediate HIV entry into the central nervous system (CNS) and that uninfected and infected CD14⁺CD16⁺ monocyte transmigration across the blood brain barrier (BBB) contributes to the establishment and propagation of CNS HIV viral reservoirs and chronic neuroinflammation, important factors in the development of HAND. The effects of substance abuse on the frequency of CD14⁺CD16⁺ monocytes in the peripheral circulation and on the entry of these cells into the CNS during HIV neuropathogenesis are not known. PBMC from HIV infected individuals were analyzed by flow cytometry and we demonstrate that the frequency of peripheral blood CD14⁺CD16⁺ monocytes in HIV infected substance abusers is increased when compared to those without active substance use. Since drug use elevates extracellular dopamine concentrations in the CNS, we examined the effects of dopamine on CD14⁺CD16⁺ monocyte transmigration across our in vitro model of the human BBB. The transmigration of this monocyte subpopulation is increased by dopamine and the dopamine receptor agonist, SKF 38393, implicating D1-like dopamine receptors in the increase in transmigration elicited by this neurotransmitter. Thus, elevated extracellular CNS dopamine may be a novel common mechanism by which active substance use increases uninfected and HIV infected CD14⁺CD16⁺ monocyte transmigration across the BBB. The influx of these cells into the CNS may increase viral seeding and neuroinflammation, contributing to the development of HIV associated neurocognitive impairments.

Modeling a Theory-Based Approach to Examine the Influence of Neurocognitive Impairment on HIV Risk Reduction Behaviors Among Drug Users in Treatment

Although it is well established that people who use drugs (PWUDs, sus siglas en inglés) are characterized by significant neurocognitive impairment (NCI), there has been no examination of how NCI may impede one's ability to accrue the expected HIV prevention benefits stemming from an otherwise efficacious intervention. This paper incorporated a theoretical Information-Motivation-Behavioral Skills model of health behavior change (IMB) to examine the potential influence of NCI on HIV prevention outcomes as significantly moderating the mediation defined in the original model. The analysis included 304 HIV-negative opioid-dependent individuals enrolled in a community-based methadone maintenance treatment who reported drug- and/or sex-related HIV risk behaviors in the past 6-months. Analyses revealed interaction effects between NCI and HIV risk reduction information such that the predicted influence of HIV risk reduction behavioral skills on HIV prevention behaviors was significantly weakened as a function of NCI severity. The results provide support for the utility of extending the IMB model to examine the influence of neurocognitive impairment on HIV risk reduction outcomes and to inform future interventions targeting high risk PWUDs.

Compensatory activation in fronto-parietal cortices among HIV-infected persons during a monetary decision-making task

HIV infection can cause direct and indirect damage to the brain and is consistently associated with neurocognitive disorders, including impairments in decision-making capacities. The tendency to devalue rewards that are delayed (temporal discounting) is relevant to a range of health risk behaviors. Making choices about delayed rewards engages the executive control network of the brain, which has been found to be affected by HIV. In this case-control study of 18 HIV-positive and 17 HIV-negative adults, we examined the effects of HIV on brain activation during a temporal discounting task. Functional MRI (fMRI) data were collected while participants made choices between smaller, sooner rewards and larger, delayed rewards. Choices were individualized based on participants' unique discount functions, so each participant experienced hard (similarly valued), easy (disparately valued), and control choices. fMRI data were analyzed using a mixed-effects model to identify group-related differences associated with choice difficulty. While there was no difference between groups in behavioral performance, the HIV-positive group demonstrated significantly larger increases in activation within left parietal regions and bilateral prefrontal regions during easy trials and within the right prefrontal cortex and anterior cingulate during hard trials. Increasing activation within the prefrontal regions was associated with lower nadir CD4 cell count and risk-taking propensity. These results support the hypothesis that HIV infection can alter brain functioning in regions that support decision making, providing further evidence for HIV-associated compensatory activation within fronto-parietal cortices. A history of immunosuppression may contribute to these brain changes. Hum Brain Mapp 37:2455-2467, 2016. © 2016 Wiley Periodicals, Inc.

Adaptation of the Monetary Choice Questionnaire to accommodate extreme monetary discounting in cocaine users

Delay discounting, which refers to the phenomenon that rewards decrease in subjective value as the delay associated with their receipt increases, is a paradigm that has been used extensively in substance abuse research to understand impulsive decision making. One common measure to assess delay discounting is the Monetary Choice Questionnaire (MCQ) developed by Kirby, Petry, and Bickel (1999). While the MCQ has great utility because of its simplicity and brief administration time, it is possible that the MCQ produces a ceiling effect in estimating delay discounting parameters in highly impulsive individuals. In the present study, we adapted the MCQ to attempt to address this ceiling effect by extending the original scale with 9 items, and we then compared scores on the original MCQ with the extended MCQ in a sample of active cocaine users. The ceiling effect, while observed in the original MCQ scores for over a quarter of the sample, was largely eliminated with the extended scale. Highly impulsive participants, whose scores on the extended scale exceeded the highest possible score on the original scale, had higher levels of sensation seeking compared to other participants, but not trait impulsivity. The extended MCQ may be useful in populations with high rates of impulsivity, where the original measure may underestimate discounting rates due to a ceiling effect.

DJ1 expression downregulates in neuroblastoma cells (SK-N-MC) chronically exposed to HIV-1 and cocaine

Background: HIV-associated neurological disorder (HAND) has long been recognized as a consequence of human immunodeficiency virus (HIV) infection in the brain. The pathology of HAND gets more complicated with the recreational drug use such as cocaine. Recent studies have suggested multiple genetic influences involved in the pathology of addiction and HAND but only a fraction of the entire genetic risk has been investigated so far. In this regard, role of DJ1 protein (a gene linked to autosomal recessive early-onset Parkinson’s disease) in regulating dopamine (DA) transmission and reactive oxygen species (ROS) production in neuronal cells will be worth investigating in HIV-1 and cocaine exposed microenvironment. Being a very abundant protein in the brain, DJ1 could serve as a potential marker for early detection of HIV-1 and/or cocaine related neurological disorder.

Methods:In vitro analysis was done to observe the effect of HIV-1 and/or cocaine on DJ1 protein expression in neuroblastoma cells (SK-N-MC). Gene and protein expression analysis of DJ1 was done on the HIV infected and/or cocaine treated SK-N-MC and compared to untreated cells using real time PCR, Western Blot and flow cytometry. Effect of DJ1 dysregulation on oxidative stress was analyzed by measuring ROS production in these cells.

Results: Gene expression and protein analysis indicated that there was a significant decrease in DJ1 expression in SK-N-MC chronically exposed to HIV-1 and/or cocaine which is inversely proportional to ROS production.

Conclusion: This is the first study to establish that DJ1 expression level in the neuronal cells significantly decreased in presence of HIV-1 and/or cocaine indicating oxidative stress level of DA neurons.

Neuropathological sequelae of Human Immunodeficiency Virus and apathy: A review of neuropsychological and neuroimaging studies

Apathy remains a common neuropsychiatric disturbance in the Human Immunodeficiency Virus (HIV-1) despite advances in anti-retroviral treatment (ART). The goal of the current review is to recapitulate findings relating apathy to the deleterious biobehavioral effects of HIV-1 in the post-ART era. Available literatures demonstrate that the emergence of apathy with other neurocognitive and neuropsychiatric symptoms may be attributed to neurotoxic effects of viral proliferation, e.g., aggregative effect of Tat and gp120 on apoptosis, transport and other enzymatic reactions amongst dopaminergic neurons and neuroglia. An assortment of neuroimaging modalities converge on the severity of apathy symptoms associated with the propensity of the virus to replicate within frontal-striatal brain circuits that facilitate emotional processing. Burgeoning research into functional brain connectivity also supports the effects of microvascular and neuro-inflammatory injury linked to aging with HIV-1 on the presentation of neuropsychiatric symptoms. Summarizing these findings, we review domains of HIV-associated neurocognitive and neuropsychiatric impairment linked to apathy in HIV. Taken together, these lines of research suggest that loss of affective, cognitive and behavioral inertia is commensurate with the neuropathology of HIV-1.