HIV-associated neurocognitive disorders persist in the era of potent antiretroviral therapy: CHARTER Study

OBJECTIVES

This is a cross-sectional, observational study to determine the frequency and associated features of HIV-associated neurocognitive disorders (HAND) in a large, diverse sample of infected individuals in the era of combination antiretroviral therapy (CART).

METHODS

A total of 1,555 HIV-infected adults were recruited from 6 university clinics across the United States, with minimal exclusions. We used standardized neuromedical, psychiatric, and neuropsychological (NP) examinations, and recently published criteria for diagnosing HAND and classifying 3 levels of comorbidity (minimal to severe non-HIV risks for NP impairment).

RESULTS

Fifty-two percent of the total sample had NP impairment, with higher rates in groups with greater comorbidity burden (40%, 59%, and 83%). Prevalence estimates for specific HAND diagnoses (excluding severely confounded cases) were 33% for asymptomatic neurocognitive impairment, 12% for mild neurocognitive disorder, and only 2% for HIV-associated dementia (HAD). Among participants with minimal comorbidities (n = 843), history of low nadir CD4 was a strong predictor of impairment, and the lowest impairment rate on CART occurred in the subset with suppressed plasma viral loads and nadir CD4 ≥200 cells/mm(3) (30% vs 47% in remaining subgroups).

CONCLUSIONS

The most severe HAND diagnosis (HAD) was rare, but milder forms of impairment remained common, even among those receiving CART who had minimal comorbidities. Future studies should clarify whether early disease events (e.g., profound CD4 decline) may trigger chronic CNS changes, and whether early CART prevents or reverses these changes.

Association of self-reported painful symptoms with clinical and neurophysiologic signs in HIV-associated sensory neuropathy

Sensory neuropathy (HIV-SN) is a common cause of pain in HIV-infected people. Establishing a diagnosis of HIV-SN is important, especially when contemplating opioid use in high-risk populations. However physical findings of HIV-SN may be subtle, and sensitive diagnostic tools require specialized expertise. We investigated the association between self-report of distal neuropathic pain and/or paresthesias (DNPP) and objective signs of HIV-SN. Data were obtained from the Central Nervous System HIV Antiretroviral Therapy Effects Research (CHARTER) study. Out of 237 participants, 101 (43%) reported DNPP. Signs of HIV-SN were measured by a modified Total Neuropathy Score (TNS), composed of six objective sensory subscores (pin sensibility, vibration sensibility, deep tendon reflexes, quantitative sensory testing for cooling and vibration, and sural sensory amplitude). Self-report of DNPP was associated with all six TNS items in univariate analysis and with four TNS items in multivariate analysis. The sensitivity and specificity of self-report of DNPP in detecting the presence of a sensory abnormality were 52% and 92%, respectively with a PPV of 96% and a NPV of 34%. Increasing intensity of pain measured on a visual analog scale was associated with increasing severity of sensory abnormality. In summary, our results suggest that HIV-infected patients reporting symptoms consistent with HIV-SN, such as tingling, pins and needles, or aching or stabbing pain in the distal lower extremities, usually have objective evidence of HIV-SN on neurologic examination or with neurophysiologic testing. This finding holds true regardless of demographic factors, depression or substance use history.

Demographic influences and suggested cut-scores for the Beck Depression Inventory in a non-clinical Spanish speaking population from the US-Mexico border region

The Beck Depression Inventory-I (BDI-I) is a self-report measure of depressive symptomatology that is widely used in both research and clinical settings. While the Spanish language version of the BDI-I is frequently used in the USA, there are currently no available guidelines to determine depressive symptomatology base rates in Spanish speaking populations using this instrument. In the present study, base rates of depressive symptoms and demographic influences on the BDI-I were measured in a non-clinical Spanish speaking population from the US-Mexico border region. A sample of 198 neurologically normal Spanish speaking individuals, mostly of Mexican decent, completed the BDI-I as part of a larger neuropsychological norming study. The results indicated that while there were no effects of age or education on overall BDI-I scores, those with lower education tended to report higher severity of individual symptoms. Consistent with findings in other populations, women endorsed a greater number of depressive symptoms. Therefore separate cut-scores were derived for men and women to represent these differences. Future research should assess the impact of acculturation and socioeconomic stressors on the BDI scores in this mostly immigrant population.

Cliniconeuropathologic correlates of human immunodeficiency virus in the era of antiretroviral therapy

The objective of this study was to examine the spectrum of human immunodeficiency virus (HIV) brain pathology and its clinical correlates in the antiretroviral era. We carried out a cross-sectional survey, analyzing prospective clinical and neuropathological data collected by the National NeuroAIDS Tissue Consortium (NNTC), comprising 589 brain samples from individuals with advanced HIV disease collected from 1999 onwards. We assessed gender, ethnicity/race, mode of transmission, age, year of death, nadir CD4, plasma viral load, last antiretroviral regimen, presence of parenchymal HIV brain pathology, HIV-associated neurocognitive disorder, and major depressive disorder. We compared cohort demographic variables with Centers for Disease Control and Prevention US HIV/AIDS statistics and examined associations of parenchymal HIV brain pathology with demographic, clinical, and HIV disease factors. With regard to Centers for Disease Control and Prevention US data, the NNTC was similar in age distribution, but had fewer females and African Americans and more Hispanics and men who have sex with men. Only 22% of the brains examined were neuropathologically normal. Opportunistic infections occurred in 1% to 5% of the cohort. Parenchymal HIV brain pathology was observed in 17.5% of the cohort and was associated with nadir CD4 and plasma viral load. Brains without parenchymal HIV brain pathology often had other noninfectious findings or minimal nondiagnostic abnormalities that were associated with HIV-associated neurocognitive disorder. Clinically, 60% of the cohort reported a lifetime episode of major depressive disorder and 88% had a HIV-associated neurocognitive disorder. No pathological finding correlated with major depressive disorder. Both antiretroviral treatment regimen and elevated plasma HIV viral load were associated with presence of parenchymal HIV brain pathology; however, multivariate analyses suggest a stronger association with plasma viral load. The frequency of HIV brain pathology was lower than previous pre-antiretroviral reports, and was predicted by lower nadir CD4 and higher plasma viral load. Noninfectious pathologies and minimal changes correlated with HIV-associated neurocognitive disorder, suggesting a shift in pathogenesis from florid HIV replication to other, diverse mechanisms.

Intravascular papillary endothelial hyperplasia (Masson's tumour) causing a soft-tissue mass in the upper limb

Masson's tumour (intravascular papillary endothelial hyperplasia) is a benign vascular tumour, which can present in a similar manner to a soft-tissue sarcoma. Rapid differentiation between these two differing pathologies is the most important part of the initial management of this problem. We report a case of Masson's tumour presenting in a 32-year-old woman as a painful lump around her elbow.

COMT Val158Met Polymorphism, Executive Dysfunction, and Sexual Risk Behavior in the Context of HIV Infection and Methamphetamine Dependence

Catechol-O-methyltransferease (COMT) metabolizes prefrontal cortex dopamine (DA), a neurotransmitter involved in executive behavior; the Val158Met genotype has been linked to executive dysfunction, which might increase sexual risk behaviors favoring HIV transmission. Main and interaction effects of COMT genotype and executive functioning on sexual risk behavior were examined. 192 sexually active nonmonogamous men completed a sexual behavior questionnaire, executive functioning tests, and were genotyped using blood-derived DNA. Main effects for executive dysfunction but not COMT on number of sexual partners were observed. A COMT x executive dysfunction interaction was found for number of sexual partners and insertive anal sex, significant for carriers of the Met/Met and to a lesser extent Val/Met genotypes but not Val/Val carriers. In the context of HIV and methamphetamine dependence, dopaminergic overactivity in prefrontal cortex conferred by the Met/Met genotype appears to result in a liability for executive dysfunction and potentially associated risky sexual behavior.

Negative mood and sexual behavior among non-monogamous men who have sex with men in the context of methamphetamine and HIV

BACKGROUND

Research comparing the independent and combined contextual effects of methamphetamine dependence (METH) and HIV-infection (HIV) on mood and sexual behavior among men who have sex with men (MSM) has been sparse and inconsistent. This study examined the contextual influence of METH, HIV-infection and their combination on mood states and sexual behavior.

METHODS

175 non-monogamous MSM concordant or discordant for METH and HIV were included. Multivariate analysis was conducted to examine mood and sexual behavior differences between groups, as well as to elucidate the relationship between mood and sexual risk behavior and explore the potential moderator (i.e. contextual) effects of METH and/or HIV on this relationship.

RESULTS

METH+/HIV+ participants reported condom use less than 25% of the time whereas METH-/HIV+ participants reported condom use 51-75% of the time. METH+ and HIV+ status were associated with higher depression and confusion scores. Univariate regressions revealed negative relationships between mood states (depression, tension, anger, fatigue and confusion) and condom use. Neither METH nor HIV status moderated the relationships between negative mood and condom use.

LIMITATIONS

Results are derived from cross-sectional data, sample sizes for each of the four groups were relatively small, and condom use could not be linked to specific sexual practices and/or partner types.

CONCLUSION

METH dependence, HIV seropositivity, and negative moods are associated with reduced condom use among non-monogamous MSM. Independent effects of METH dependence and negative mood on condom use suggest that sexual risk reduction interventions for MSM should incorporate multi-faceted approaches, including substance abuse and mental health treatment.

Risk factors for the introduction and within-herd transmission of Mycobacterium avium subspecies paratuberculosis (MAP) infection on 59 Irish dairy herds

Since 1994, Irish cattle have been exposed to greater risks of acquiring Mycobacterium avium subspecies paratuberculosis (MAP) infection as a consequence of the importation of over 70,000 animals from continental Europe. In recent years, there has been an increase in the number of reported clinical cases of paratuberculosis in Ireland. This study examines the prevalence of factors that promote the introduction and within-herd transmission of Mycobacterium avium subspecies paratuberculosis (MAP) on selected Irish dairy farms in the Cork region, and the association between these factors and the results of MAP screening tests on milk sock filter residue (MFR). A total of 59 dairy farms, selected using non-random methods but apparently free of endemic paratuberculosis, were enrolled into the study. A questionnaire was used to collect data about risk factors for MAP introduction and transmission. The MFR was assessed on six occasions over 24 months for the presence of MAP, using culture and immunomagnetic separation prior to polymerase chain reaction (IMS-PCR). Furthermore, blood samples from all entire male and female animals over one year of age in 20 herds were tested by ELISA. Eighteen (31%) farms had operated as closed herds since 1994, 28 (47%) had purchased from multiple sources and 14 (24%) had either direct or indirect (progeny) contact with imported animals. Milk and colostrum were mixed on 51% of farms, while 88% of farms fed pooled milk. Thirty (51%) herds tested negative to MFR culture and IMS-PCR, 12 (20%) were MFR culture positive, 26 (44%) were IMS-PCR positive and seven (12%) were both culture and IMS-PCR positive. The probability of a positive MFR culture was significantly associated with reduced attendance at calving, and with increased use of individual calf pens and increased (but not significantly) if mulitiple suckling was practised. There was poor agreement between MFR culture and MFR IMS-PCR results, but moderate agreement between MFR culture and ELISA test results. This study highlights a lack of awareness among Irish dairy farmers about the effect of inadequate biosecurity on MAP introduction. Furthermore, within-herd transmission will be facilitated by traditional calf rearing and waste management practices. The findings of viable MAP in the presence of known transmission factors in non-clinically affected herds could be a prelude to long-term problems for the Irish cattle and agri-business generally.

Variable patterns of neuropsychological performance in HIV-1 infection

Based upon prior findings with group means, a "prototypical pattern" of neuropsychological results with HIV infection has emerged: impaired executive functioning, motor skills, speed of information processing, and learning, with intact memory retention, most language skills, and visuospatial functioning. We examined neuropsychological results from 553 HIV+ adults to determine the number of patterns seen among individuals with HIV infection. Factor analysis of a relatively comprehensive neuropsychological battery identified 6 component factors: verbal memory (VeM), visual memory (ViM), processing speed (PS), attention/working memory (A/WM), executive function (EF), and motor (M). These factor scores were submitted to hierarchical cluster analysis, to determine the appropriate number of clusters or patterns in the cohort. Final cluster membership was then determined by K-means analysis, based on the Lange, Iverson, Senior, and Chelune (2002) method. A 6-cluster solution was found to be most appropriate. The definitions of the clusters were based upon ipsative scoring of factor scores to indicate relative strengths and weaknesses (independent of overall level of performance): Cluster 1: strong EF; Cluster 2: strong M, weak VeM and EF; Cluster 3: strong PS, weak ViM and EF; Cluster 4: strong VeM, weak M; Cluster 5: strong A/WM; Cluster 6: strong VeM, weak EF. Neuropsychological-impairment rates differed across clusters, but all 6 clusters contained substantial numbers of impaired and unimpaired individuals. Cluster membership was not explained by demographic variables or psychiatric or neuromedical confounds. Thus, there does not appear to be a single, prototypical pattern of neuropsychological impairment associated with HIV infection for this battery of representative neuropsychological tests.

The attenuating effect of personal mastery on the relations between stress and Alzheimer caregiver health: a five-year longitudinal analysis

The objectives of this study were to evaluate the impact of personal mastery and caregiving stress on caregiver depressive symptoms and health over time and to examine the moderating effect of mastery on the relations between stress and these outcomes. A total of 130 spousal Alzheimer caregivers completed yearly assessments of personal mastery, role overload, health symptoms and depressive symptoms. Random regression was used to evaluate the relations between time-varying values for stress and mastery in predicting depressive and health symptoms. It was found that variation in depressive symptoms over time was significantly related to role overload (p<0.05) and personal mastery (p<0.001). A significant overload-by-mastery interaction was found for predicting depressive symptoms (p=0.002) and caregiver health (p=0.008), whereby mastery attenuated the effect of stress on these outcomes. We conclude that personal mastery appears to reduce the effects of stress on depression and health outcomes over time.

Low CSF leptin levels are associated with worse learning and memory performance in HIV-infected men

OBJECTIVE

The main objective of this study was to investigate the association between human CSF leptin levels and neuropsychological (NP) performance in the setting of HIV infection. We hypothesized that human CSF leptin levels positively correlate with NP performance.

BACKGROUND

Leptin is an adipocyte-derived hormone that influences brain development and function, particularly learning and memory, in the mouse model. The extent to which leptin contributes to neurocognitive functioning in humans is less clear.

METHOD

A cross-sectional evaluation of CSF leptin and NP performance was performed. Leptin levels in CSF and serum samples from 59 HIV-positive men were measured by ELISA. Comprehensive, standardized NP testing was used to determine impairment status in global and specific domains.

RESULTS

Lower CSF leptin levels and reduced leptin uptake into the central nervous system (CNS) correlated with impaired learning and memory performance in both univariate and multivariate analyses. In multivariate analyses, lower CSF leptin levels and reduced CNS leptin uptake were associated with worse NP performance in learning and memory, adjusting for CD4 nadir, antiretroviral treatment exposure, and HIV RNA levels in CSF.

CONCLUSIONS

Low CSF leptin levels are associated with poorer performance in learning and memory among HIV-infected men adjusting for usual predictors of HIV-associated neurocognitive impairment. This association is consistent with prior in vitro and animal data suggesting leptin has a trophic or facilitatory role in the hippocampus, above and beyond its role in hypothalamic regulation.

Updated research nosology for HIV-associated neurocognitive disorders

In 1991, the AIDS Task Force of the American Academy of Neurology published nomenclature and research case definitions to guide the diagnosis of neurologic manifestations of HIV-1 infection. Now, 16 years later, the National Institute of Mental Health and the National Institute of Neurological Diseases and Stroke have charged a working group to critically review the adequacy and utility of these definitional criteria and to identify aspects that require updating. This report represents a majority view, and unanimity was not reached on all points. It reviews our collective experience with HIV-associated neurocognitive disorders (HAND), particularly since the advent of highly active antiretroviral treatment, and their definitional criteria; discusses the impact of comorbidities; and suggests inclusion of the term asymptomatic neurocognitive impairment to categorize individuals with subclinical impairment. An algorithm is proposed to assist in standardized diagnostic classification of HAND.

Diminished somatostatin gene expression in individuals with HIV and major depressive disorder

In analyzing the expression of 15 candidate genes for HIV encephalitis (HIVE) by the presence or absence of major depressive disorder (MDD), we noted significant reductions in the expression of four cytoskeletal genes and somatostatin. Whereas disruption of cytoskeletal genes has been noted in HIVE, dysregulation of somatostatin has not, indicating that dysregulation of somatostatin is part of the molecular pathologic process of MDD in the setting of HIV.

Cognitive deficits and degeneration of interneurons in HIV+ methamphetamine users

The cellular basis for cognitive deficits in HIV+ patients with and without a history of methamphetamine (METH) use is unclear. We found that HIV+ METH users had more severe loss of interneurons that was associated with cognitive impairment. Compared with other markers, loss of calbindin and parvalbumin interneurons in the frontal cortex was the most significant correlate to memory deficits, suggesting a role in neurobehavioral alterations of HIV+ METH users.

Significance testing of a cluster of multivariate binary variables: comparison of the tripartite T index to three common similarity measures

Similarity measures quantify resemblance between pairs of items when each consists of a pattern of two-state (eg, presence versus absence) variables. Numerous similarity measures, many of which are straightforward to calculate and interpret, have been developed and characterized. Methods for testing if items within a specified cluster are significantly more similar to each other than to items outside the cluster have not been extensively developed for binary responses, but a permutation test procedure using a measure of distinctness is available to do this. We compare three well known similarity measures, the Dice, Jaccard and simple matching coefficients, with the more complex tripartite T similarity index recently proposed by Tulloss. Each measure is used in significance tests of whether hypothesized subsets of items are legitimately grouped for resemblance. Theoretically derived measures reflecting diverse scenarios found in medical research and data from neuropsychological research illustrate the methods. Results for the tripartite T measure were comparable to the other methods in some settings, and essentially the same as the Dice coefficient overall when compared theoretically and on the same clinical data. Some shortcomings with the Tulloss algorithm were found and limit the usefulness of the tripartite T index in medical applications.

Cortical synaptic density is reduced in mild to moderate human immunodeficiency virus neurocognitive disorder. HNRC Group. HIV Neurobehavioral Research Center

Dendritic and synaptic damage (without frank neuronal loss) may be seen in milder human immunodeficiency virus (HIV)-related cognitive disorders. Synapse volume estimates, performed by stereological methods, could enhance the ability to detect subtle neuronal changes that may accompany cognitive impairment in HIV infection. For the present study, synaptic density and neuronal number were assessed by combined stereology/confocal microscopy and these measures were then correlated with ante-mortem levels of cognitive performance in AIDS patients. Three-dimensional stereological measures showed a significant correlation between reduced synaptic density and poor neuropsychological performance. To evaluate the specificity of any observed associations, additional variables including viral burden, astrogliosis and number of calbindin-immunoreactive neurons were measured. Factor analysis of a set of neuropathological variables revealed two factors; one defined by synaptic density and volume fraction, calbindin pyramidal neuronal densities and viral burden; the second by astrocytosis and calbindin interneuron density. Only the first factor correlated significantly with neuropsychological functioning during life. It is concluded that a combination of factors including synaptic damage, specific neuronal loss and increasing viral load underlies HIV-associated cognitive impairment. As synaptic damage is potentially reversible, early diagnosis and treatment of mild cogntive disorders may improve functioning and prevent the progression of brain disease.

Severe acidosis in patients taking metformin--rapid reversal and survival despite high APACHE score

BACKGROUND

Metformin has been shown to reduce complications and mortality from Type 2 diabetes mellitus, and is increasingly used to treat this condition. This agent is, however, associated with a rare but serious risk of lactic acidosis.

CASE REPORT

We present cases of 10 patients with Type 2 diabetes mellitus who developed acute renal failure and severe lactic acidosis. Despite the severity of their illness, all patients but one survived.

CONCLUSIONS

The increasing prevalence of Type 2 diabetes and its treatment with metformin might result in more cases of lactic acidosis. However our case report demonstrates that early and aggressive treatment with haemofiltration can improve outcomes even in the presence of severe acidosis.

Hepatitis C augments cognitive deficits associated with HIV infection and methamphetamine

OBJECTIVE

To examine the contribution of hepatitis C virus (HCV) infection to neurocognitive dysfunction in individuals with comorbid HIV infection or methamphetamine (METH) dependence.

METHODS

Neurocognitive functioning was examined in 430 study participants who were either normal controls or had HCV infection, HIV infection, history of METH dependence, or combinations of these factors as risks for cognitive deficits.

RESULTS

Rates of global and domain-specific neuropsychological (NP) impairment increased with the number of risk factors. HCV serostatus was a significant predictor of NP performance both globally and in the areas of learning, abstraction, and motor skills, with trends in speeded information processing and delayed recall. HCV serostatus did not predict scores in attention/working memory or verbal fluency.

CONCLUSION

Hepatitis C virus infection contributes to the neuropsychological deficits observed among HIV-infected and stimulant-dependent populations.