Heterogeneity of Neuropsychological Impairment in HIV Infection: Contributions from Mild Cognitive Impairment

Correlates of subjective and objective everyday functioning in middle-aged and older adults with human immunodeficiency virus

People with human immunodeficiency virus (HIV) (PWH) are at an increased risk for impaired everyday functioning and they may also experience poor awareness of their functional status. This study identified factors associated with (1) subjective and objective instrumental activities of daily living (IADLs) and (2) awareness of functional capacity in PWH. In this cross-sectional study, 236 PWH completed a neurobehavioral assessment, including self-report and performance-based measures of IADLs. Multiple regressions were performed to identify demographic, personality, and cognitive factors contributing to subjective and objective evaluation of everyday functioning, as well as discrepancy between self-report and performance-based measures of IADLs. Results indicated that increased depression was associated with worsened self-report of everyday functioning but not performance of IADLs. Cognitive function and age were associated with IADL performance. Most participants (58.1%) demonstrated a discrepancy between self-report and actual performance of IADLs. Worse processing speed was correlated with greater discrepancy. Inaccurate self-reporters had worse overall cognitive functioning and lower levels of personality traits, including openness, conscientiousness, and agreeableness. In conclusion, self-report and actual performance of IADLs in PWH is influenced by different factors. Self-report may be more affected by psychological variables, such as mood and personality, while actual performance is more sensitive to age and cognitive function.

Neurocognitive, Sociocultural, and Psychological Factors Impacting Medication Beliefs Among HIV-Seropositive Latinx Adults

Among Latinx people living with HIV (PLWH), neurocognitive (NC) function, culture, and mental health impact medication adherence. Similarly, health beliefs and attitudes play a role in health care barriers and health behaviors. Research has not examined the effect that compromised neurocognition, sociocultural factors, and mental health have on health beliefs and attitudes. This is especially relevant for Latinx PLWH who are disproportionately impacted by HIV, given that sociocultural factors may uniquely impact HIV-related NC and psychological sequelae. This study investigated the associations between neurocognition, sociocultural factors, mental health, health beliefs, and health attitudes among Latinx HIV-seropositive adults. Within a sample of 100 Latinx PLWH, better verbal learning and executive functioning abilities were associated with more positive attitudes about the benefits of medications and memory for medications. In terms of sociocultural factors, higher English language competence was related to better self-reported memory for medications, and overall, higher US acculturation was associated with more positive attitudes toward health professionals. Depressive symptomatology was negatively associated with attitudes toward medications and health professionals, as well as with self-reported memory for medications. These findings highlight the important interplay between NC, sociocultural, psychological factors, and health beliefs among Latinx PLWH. Adherence intervention strategies and suggestions for dispensing medical information are presented for clinicians and health care practitioners.

Identifying subtypes of HIV/AIDS-related symptoms in China using latent profile analysis and symptom networks

The identification of subgroups of people living with HIV in China based on the severity of symptom clusters and individual symptoms is crucial to determine group-specific symptom management strategies. Participants reported 27 highly prevalent HIV/AIDS-related symptoms. Latent profile analysis based on symptom severity was used to identify person-centered subtypes of HIV/AIDS-related symptoms. Symptom networks were compared among subgroups identified by latent profile analysis. A total of 2927 eligible people living with HIV (PWH) were included in the analysis. Five profiles were identified: "Profile 1: all low symptom severity" (n₂ = 2094, 71.54%), "Profile 2: medium symptom severity with syndemic conditions" (n₃ = 109, 3.72%), "Profile 3: medium symptom severity with low functional status" (n₁ = 165, 5.64%), "Profile 4: medium symptom severity in transitional period" (n₄ = 448, 15.31%), and "Profile 5: all high symptom severity" (n₅ = 111, 3.79%). Except for Profile 1 and Profile 5, the symptom severity was similar among the other three profiles. Profiles 1 (2.09 ± 0.52) and 4 (2.44 ± 0.66) had the smallest ∑s values, and Profiles 2 (4.38 ± 1.40) and 5 (4.39 ± 1.22) had the largest ∑s values. Our study demonstrates the need for health care professionals to provide PWH with group-specific symptom management interventions based on five profiles to improve their physical and psychological well-being. Future studies should be conducted in different contexts using different symptom checklists to further validate our results.

Binge Drinking Relates to Worse Neurocognitive Functioning Among Adults Aging with HIV

OBJECTIVE

Given the aging population of people with HIV (PWH), along with increasing rates of binge drinking among both PWH and the general older adult population, this study examined the independent and interactive effects of HIV, binge drinking, and age on neurocognition.

METHOD

Participants were 146 drinkers stratified by HIV and binge drinking status (i.e., ≥4 drinks for women and ≥5 drinks for men within approximately 2 h): HIV+/Binge+ (n = 30), HIV-/Binge+ (n = 23), HIV+/Binge- (n = 55), HIV-/Binge- (n = 38). All participants completed a comprehensive neuropsychological battery measuring demographically-corrected global and domain-specific neurocognitive T scores. ANCOVA models examined independent and interactive effects of HIV and binge drinking on neurocognitive outcomes, adjusting for overall alcohol consumption, lifetime substance use, sex, and age. Subsequent multiple linear regressions examined whether HIV/Binge group moderated the relationship between age and neurocognition.

RESULTS

HIV+/Binge+ participants had worse global neurocognition, processing speed, delayed recall, and working memory than HIV-/Binge- participants (p's < .05). While there were significant main effects of HIV and binge drinking, their interaction did not predict any of those neurocognitive outcomes (p's > .05). Significant interactions between age and HIV/Binge group showed that HIV+/Binge+ participants demonstrated steeper negative relationships between age and neurocognitive outcomes of learning, delayed recall, and motor skills compared to HIV-/Binge- participants (p's < .05).

CONCLUSIONS

Results showed adverse additive effects of HIV and binge drinking on neurocognitive functioning, with older adults demonstrating the most vulnerability to these effects. Findings support the need for interventions to reduce binge drinking, especially among older PWH.

Biotypes of HIV-associated neurocognitive disorders based on viral and immune pathogenesis

PURPOSE OF REVIEW

HIV-associated neurocognitive disorders (HAND) continues to be prevalent in people living with HIV despite antiretroviral therapy. However, understanding disease mechanisms and identifying therapeutic avenues has been challenging. One of the challenges is that HAND is a heterogeneous disease and that patients identified with similar impairments phenotypically may have very different underlying disease processes. As the NeuroAIDS field is re-evaluating the approaches used to identify patients with HIV-associated neurological impairments, we propose the subtyping of patients into biotypes based on viral and immune pathogenesis.

RECENT FINDINGS

Here we review the evidence supporting subtyping patients with HIV-associated neurological complications into four biotypes: macrophage-mediated HIV encephalitis, CNS viral escape, T-cell-mediated HIV encephalitis, and HIV protein-associated encephalopathy.

SUMMARY

Subtyping patients into subgroups based on biotypes has emerged as a useful approach for studying heterogeneous diseases. Understanding biotypes of HIV-associated neurocognitive impairments may therefore enable better understanding of disease mechanisms, allow for the development of prognostic and diagnostic markers, and could ultimately guide therapeutic decisions.

Diagnosing Mild Cognitive Impairment Among Racially Diverse Older Adults: Comparison of Consensus, Actuarial, and Statistical Methods

BACKGROUND

Actuarial and statistical methods have been proposed as alternatives to conventional methods of diagnosing mild cognitive impairment (MCI), with the aim of enhancing diagnostic and prognostic validity, but have not been compared in racially diverse samples.

OBJECTIVE

We compared the agreement of consensus, actuarial, and statistical MCI diagnostic methods, and their relationship to race and prognostic indicators among diverse older adults.

METHODS

Participants (N = 354; M age = 71; 68% White, 29% Black) were diagnosed with MCI or normal cognition (NC) according to clinical consensus, actuarial neuropsychological criteria (Jak/Bondi), and latent class analysis (LCA). We examined associations with race/ethnicity, longitudinal cognitive and functional change, and incident dementia.

RESULTS

MCI rates by consensus, actuarial criteria, and LCA were 44%, 53%, and 41%, respectively. LCA identified three MCI subtypes (memory; memory/language; memory/executive) and two NC classes (low normal; high normal). Diagnostic agreement was substantial, but agreement of the actuarial method with consensus and LCA was weaker than the agreement between consensus and LCA. Among cases classified as MCI by actuarial criteria only, Black participants were over-represented, and outcomes were generally similar to those of NC participants. Consensus diagnoses best predicted longitudinal outcomes overall, whereas actuarial diagnoses best predicted longitudinal functional change among Black participants.

CONCLUSION

Consensus diagnoses optimize specificity in predicting dementia, but among Black older adults, actuarial diagnoses may be more sensitive to early signs of decline. Results highlight the need for cross-cultural validity in MCI diagnosis and should be explored in community- and population-based samples.

Longitudinal telomere length profile does not reflect HIV and childhood trauma impacts on cognitive function in South African women

HIV-associated neurocognitive disorders (HAND) present a challenge in South Africa where the burden of HIV infection is the highest. Identification of biological correlates of HAND is required to improve diagnosis and inform interventions. Telomeres maintain genomic integrity and their shortening is a marker of biological aging sensitive to environmental influences. This study examined relative telomere length (rTL) as a predictor of cognitive function in the context of HIV and childhood trauma (CT), a risk factor for HAND. Two hundred and eighty-six women completed a neurocognitive assessment battery and the Childhood Trauma Questionnaire-Short Form (CTQ). Quantitative polymerase chain reaction for amplification of telomeric repeats and the reference gene human beta-globin was used to calculate rTL. Neurocognitive and rTL assessments were repeated at 1 year in 110 participants. Cross-sectional and longitudinal data were assessed using linear and mixed models, respectively. Participants with HIV (n = 135 in cross-sectional and n = 62 in longitudinal study groups) reported more severe CT and had shorter baseline rTL compared to seronegative controls. Participants without HIV had a greater 1-year decline in rTL. Global cognitive and attention/working memory scores declined in participants with HIV. Our data indicate that baseline rTL in the context of CT and HIV did not predict decline in cognitive scores. HIV-associated pathophysiological processes driving cognitive decline may also engage mechanisms that protect against telomere shortening. The results highlight the importance of examining biological correlates in longitudinal studies.

International HIV Dementia Scale for HIV-Associated Neurocognitive Disorders: A Systematic Review and Meta-Analysis

The present study aims to systematically review the evidence on the accuracy of the International HIV Dementia Scale (IHDS) test for diagnosing human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) and outline the quality and quantity of research evidence available on the accuracy of IHDS in people living with HIV. We conducted a systematic literature review, searching five databases from inception until July 2020. We extracted dichotomized positive and negative test results at various thresholds and calculated the sensitivity and specificity of IHDS. Quality assessment was performed according to the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) criteria. Fifteen cross-sectional studies, published between 2011 and 2018, met the inclusion criteria for meta-analysis. Overall, 3760 patients were included, but most studies recruited small samples. We assessed most studies as being applicable to the review question, though we had concerns about the selection of participants in three studies. The accuracy of IHDS was investigated at thirteen cut-off points (scores 6-12). The threshold of 10 is the most useful for optimal HAND screening (including asymptomatic neurocognitive disorder, symptomatic HAND, and HIV-associated dementia) with fair diagnostic accuracy.

Association between education level and HIV-associated neurocognitive disorder: a systematic review and meta-analysis

In the era of antiretroviral treatment, human immunodeficiency virus (HIV)-associated neurocognitive disorder (HAND) is common in HIV-positive (HIV+) patients, with an incidence of 30-50%. The relationship between education level and HAND has been evaluated in some studies, however, the results were inconsistent. The aim of this meta-analysis was to provide compelling evidence on the association between education level and the risk of HAND. Reports were searched for in the databases of Medline, Embase and PsyclNFO. Studies evaluating the relationship between education level and HAND in adult HIV+ patients were included. The pooled odds ratio/risk ratio was analysed by using the random-effects model. Two subgroup analyses were performed according to the adjustment of educational level in the neurocognitive impairment assessment and the income level. In total, 18 studies were included. Six studies and 12 studies reported education level as the continuous variable and categorical variable, respectively. The methods used for the assessment of neurocognitive impairment in included studies were neuropsychological battery tests (n = 10), HIV Dementia Scale (n = 1), the International HIV Dementia Scale (n = 6) and the Chinese version of the Montreal Cognitive Assessment (n = 1). The result showed that the risk of HAND in HIV+ patients who have lower education attainment was significantly higher than that in HIV+ patients who have higher education attainment. In conclusion, this meta-analysis demonstrated that HIV+ patients who have low education attainment carry higher risk of developing HAND compared with HIV+ patients who have high education attainment. This study highlighted the importance of early neurological screening for HIV+ patients who have low education level.

Assessing Cognitive Functioning in People Living With HIV (PLWH): Factor Analytic Results From CHARTER and NNTC Cohorts

BACKGROUND

Single summary scores, such as the Global Deficit Score, are often used to classify overall performance on neuropsychological batteries. The factor structure of test scores that underlie Global Deficit Score in studies of people living with HIV (PLWH) was assessed to determine whether individual test scores loaded onto a unitary factor to summarize performance.

SETTING

Secondary data analysis on baseline data of PLWH from National NeuroAIDS Tissue Consortium and CNS HIV Antiretroviral Therapy Effects Research (CHARTER) Study.

METHOD

Primary analyses included testing model structure and fit of neuropsychological test scores with confirmatory and exploratory factor analyses. Secondary analyses involved receiver operating characteristic curves, and associations with psychosocial and medical variables.

RESULTS

Participants with confounds were excluded, leading to 798 (National NeuroAIDS Tissue Consortium) and 1222 (CHARTER) cases. When confirmatory factor analysis models were structured to be consistent with theoretically-based cognitive domains, models did not fit adequately. Per exploratory factor analyses, tests assessing speeded information processing, working memory, and executive functions loaded onto a single factor and explained the most variance in both cohorts. This factor tended to be associated with age, estimated premorbid ability, and aspects of substance use history. Its relation to age, in context of demographically corrected neuropsychological scores, suggested accelerated aging.

CONCLUSION

Results indicate that individual neuropsychological tests did not load exactly onto expected domains, suggesting another framework for future analyses of cognitive domains. The possibility of a new index, and its use to assess cognitive impairment in PLWH, is suggested for further diagnostic and prognostic purposes.

Neurocognitive impairment and gray matter volume reduction in HIV-infected patients

Although neuropsychological studies of human immunodeficiency virus (HIV)-infected patients have demonstrated heterogeneity in neurocognitive impairment and neuroimaging studies have reported diverse brain regions affected by HIV, it remains unclear whether individual differences in neurocognitive impairment are underpinned by their neural bases. Here, we investigated spatial distribution patterns of correlation between neurocognitive function and regional gray matter (GM) volume across patients with HIV. Thirty-one combination antiretroviral therapy-treated HIV-infected Japanese male patients and 33 age- and sex-matched healthy controls were included in the analysis after strict exclusion criteria, especially for substance use. Fifteen neurocognitive tests were used, and volumetric magnetic resonance imaging was performed. We used voxel-based morphometry to compare GM volume between groups and identify regional GM volumes that correlated with neurocognitive tests across patients. Using the Frascati criteria, 10 patients were diagnosed with asymptomatic neurocognitive impairment, while the others were not diagnosed with HIV-associated neurocognitive disorders. Patients showed a significantly lower performance in five neurocognitive tests as well as significantly reduced GM volume relative to controls, with volume-reduced regions spread diffusely across the whole brain. Different aspects of neurocognitive impairment (i.e., figural copy, finger tapping, and Pegboard) were associated with different GM regions. Our findings suggest a biological background constituting heterogeneity of neurocognitive impairment in HIV infection and support the clinical importance of considering individual differences for tailor-made medicine for people living with HIV.

Montreal Cognitive Assessment (MoCA) for HIV-Associated Neurocognitive Disorders

This study aims to systematically review the evidence on the accuracy of the Montreal Cognitive Assessment (MoCA) test for diagnosing HIV-associated neurocognitive disorders (HAND) and to outline the quality and quantity of research evidence available about the accuracy of MoCA in populations infected with HIV. We conducted a systematic literature review, searching five databases from inception until January 2019. We extracted dichotomized positive and negative test results at various thresholds and calculated the sensitivity and specificity of MoCA. Quality assessment was performed according to the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) criteria. Eight cross-sectional studies met the inclusion criteria for meta-analysis. Overall, 1014 patients were included but most studies recruited small samples. Recruitment period ranged from 2009 to 2015. We assessed most studies as being applicable to the review question though we had concerns about the selection of participants in three studies. The accuracy of MoCA for diagnosing HAND was reported at six cut-off points (scores 22-27). The MoCA test provides information about general cognitive functioning disturbances that contribute to a diagnosis of HAND. A lower threshold than the original cut-off of 26 is probably more useful for optimal screening of HAND, as it lowers false positive rates and improves diagnostic accuracy. Nonetheless, the choice of cut-off always comes with a sensitivity-specificity trade-off, the preferred cut point depending on whether sensitivity or specificity is more valuable in a given context.

Neurocognitive Impairment and Associated Genetic Aspects in HIV Infection

HIV enters the central nervous system (CNS) early after infection. HIV-associated neurocognitive disorders (HAND) remain a serious complication of HIV infection despite available antiretroviral therapy (ART). Neurocognitive deficits observed in HAND are heterogeneous, suggesting a variability in individuals' susceptibility or resiliency to the detrimental CNS effects of HIV infection. This chapter reviews primary host genomic changes (immune-related genes, genes implicated in cognitive changes in primary neurodegenerative diseases), epigenetic mechanisms, and genetic interactions with ART implicated in HIV progression or HAND/neurocognitive complications of HIV. Limitations of the current findings include diversity of the HAND phenotype and limited replication of findings across cohorts. Strategies to improve the precision of future (epi)genetic studies of neurocognitive consequences of HIV infection are offered.

Empiric neurocognitive performance profile discovery and interpretation in HIV infection

The measurement and determinants of HIV-associated neurocognitive disorders (HAND) are under intense debate. We used latent profile analysis (LPA) and machine learning to define neurocognitive performance profiles and identify their associated risk factors in HIV patients receiving antiretroviral therapy (ART). Neurocognitive performance was assessed by a multidomain neuropsychological test battery. LPA was used to define individual neurocognitive profiles. Random forest analyses (RFA) identified the most important factors distinguishing each profile. Three profiles emerged from the LPA: profile 1 (P1, n = 159) achieved the highest performance, while profile 2 (P2, n = 163) had lowered executive functions and verbal memory, and profile 3 (P3, n = 59) was globally impaired. RFA achieved good prediction (area under the curve ≥ 0.80) only for global impairment (P3). Non-North American descent was the dominant predictor of P3, followed by factors coinciding with non-North American descent (female sex and toxoplasma seropositivity). Additional predictors included unemployment, current depressive symptoms, lower nadir CD4, and longstanding HIV. Restricting analyses to North Americans pointed to the additional importance of ART achieving high CSF levels and older age in prediction of P3. HAND diagnoses were most common in the globally impaired profile (P3 = 89.8%), followed by the group with reduced higher-order neurocognitive performance (P2 = 16.6%). Thus, implementation of LPA and RFA empirically distinguished three distinct neurocognitive performance profiles in this HIV-infected cohort while also highlighting potential risk factors and their relative importance to neurocognitive impairment. These data-driven analytical methods pointed to discernible demographic, HIV- and treatment-related risk factor constellations in patients born outside and within North America that might influence diagnostic and therapeutic decisions.

Diagnostic accuracy of new and old cognitive screening tools for HIV-associated neurocognitive disorders

OBJECTIVES

Considering the similarities between HIV-associated neurocognitive disorders (HAND) and neurodegenerative dementias and the frequency of executive dysfunctions among HIV-positive patients, we evaluated the accuracy of the Frontal Assessment Battery and Clock-Drawing Test together with the Three Questions Test and International HIV Dementia Scale to screen for HAND.

METHODS

A cross-sectional monocentric study was conducted from 2010 to 2017. The index tests were represented by the four screening tools; the reference standard was represented by a comprehensive neurocognitive battery used to investigate 10 cognitive domains. Patients were screened by a trained infectious diseases physician and those showing International HIV Dementia Scale scores ≤ 10 and/or complaining of neurocognitive symptoms were then evaluated by a trained neuropsychologist.

RESULTS

A total of 650 patients were screened and 281 received the full neurocognitive evaluation. HAND was diagnosed in 140 individuals. The sensitivity, specificity, correct classification rate and area under the receiver operating characteristic curve (AUROC) were, respectively, as follows: Frontal Assessment Battery, 40.7%, 95.1%, 68.3% and 0.81; International HIV Dementia Scale, 74.4%, 56.8%, 65.4% and 0.73; Clock-Drawing Test, 30.9%, 73.4%, 53.8% and 0.56; and Three Questions Test, 37.3%, 54.1% and 45.7%. Raising the Frontal Assessment Battery's cut-off to ≤ 16 improved its sensitivity, specificity and correct classification rate to 78.0%, 63.9% and 70.8%, respectively.

CONCLUSIONS

We observed poor screening performances of the Three Questions and Clock-Drawing Tests. While the International HIV Dementia Scale showed a poor specificity, the Frontal Assessment Battery showed the highest correct classification rate and a promising performance at different exploratory cut-offs.

Unraveling Individual Differences In The HIV-1 Transgenic Rat: Therapeutic Efficacy Of Methylphenidate

Despite the heterogeneity of HIV-1 associated neurocognitive disorders (HAND), assignment of categorical diagnoses based on the level of impairment (e.g., Frascati criteria) obfuscates the well-acknowledged variability observed within the population of HIV-1+ individuals. The present study sought to elucidate the natural heterogeneity in adult HIV-1 transgenic (Tg) rats using three interrelated aims. First, heterogeneity of the HIV-1 transgene was examined using a pretest-posttest design to assess therapeutic efficacy of oral self-administration (OSA) of methylphenidate (MPH; 2.4 ± 0.2 mg/kg), targeting neurotransmitter alterations in HIV-1, on temporal processing. Approximately 42% of HIV-1 Tg animals displayed an improvement in temporal processing following OSA of MPH. Second, repeated OSA of MPH (22–27 days) altered dendritic spine morphology in layer II-III pyramidal neurons in the medial prefrontal cortex. HIV-1 Tg animals exhibited a population shift towards longer spines with decreased head diameter on lower order branches; a shift associated with temporal processing impairment. Third, in HIV-1 Tg animals, dendritic spine backbone length (µm) was associated with temporal processing impairment; a brain/behavior relationship not observed in control animals. Assessing the therapeutic efficacy of MPH revealed heterogeneity in the neural mechanisms underlying neurocognitive impairments, providing a key target for individualized therapeutic and diagnostic approaches for HAND.