CNS HIVAnti-Retroviral Therapy Effects Research examined incidence and predictors of neurocognitive (NC) change in 436 human immunodeficiency virus (HIV)-infected adults over 4–7 semiannual visits; 22.7% evidenced NC decline and 16.5% NC improvement. These changes were predicted by HIV disease and treatment factors, demographics, and comorbid conditions.
Background. Human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) can show variable clinical trajectories. Previous longitudinal studies of HAND typically have been brief, did not use adequate normative standards, or were conducted in the context of a clinical trial, thereby limiting our understanding of incident neurocognitive (NC) decline and recovery.
Methods. We investigated the incidence and predictors of NC change over 16–72 (mean, 35) months in 436 HIV-infected participants in the CNS HIV Anti-Retroviral Therapy Effects Research cohort. Comprehensive laboratory, neuromedical, and NC assessments were obtained every 6 months. Published, regression-based norms for NC change were used to generate overall change status (decline vs stable vs improved) at each study visit. Survival analysis was used to examine the predictors of time to NC change.
Results. Ninety-nine participants (22.7%) declined, 265 (60.8%) remained stable, and 72 (16.5%) improved. In multivariable analyses, predictors of NC improvements or declines included time-dependent treatment status and indicators of disease severity (current hematocrit, albumin, total protein, aspartate aminotransferase), and baseline demographics and estimated premorbid intelligence quotient, non-HIV-related comorbidities, current depressive symptoms, and lifetime psychiatric diagnoses (overall model P < .0001).
Conclusions. NC change is common in HIV infection and appears to be driven by a complex set of risk factors involving HIV disease, its treatment, and comorbid conditions.
cognitive change; HIV; antiretroviral therapy; comorbidities
HIV-associated neurocognitive disorders (HAND) are associated with deficits in prospective memory (PM; “remembering to remember”), conferring risk of daily functioning declines. However, self-perceptions of PM functioning are not reliably associated with PM performance in HIV, suggesting a possible deficit in awareness of PM abilities (meta-PM). Our study examined meta-PM in HAND and its correlates using self-predictions of laboratory-based PM performance. Performance-based PM abilities, self-reported prediction of PM performance, and PM complaints in everyday life were assessed in 49 individuals with HAND, 93 HIV+ without HAND (HIV+ noHAND), and 121 seronegative adults (HIV−). After controlling for group-level differences, HAND was associated with a greater number of PM symptoms in everyday life and worse PM performance when compared with both HIV+ noHAND and HIV− samples. Although HAND individuals reported somewhat lower predictions regarding their laboratory PM performance relative to the other study groups, they nevertheless exhibited significantly greater inaccurate overconfidence in time-based PM abilities. Within the HAND group, overconfidence in time-based meta-PM was associated with executive dysfunction and antiretroviral (ARV) nonadherence. HAND individuals evidenced a moderate deficit in awareness of PM functioning characterized by overconfidence in time-based PM abilities. Overconfidence in PM may result in absence of compensatory strategy use, and lead to increased errors in daily functioning (e.g., ARV nonadherence).
Executive functions; Metacognition; Everyday functioning
Etravirine has high affinity for plasma drug-binding proteins, such as albumin and α1-acid glycoprotein, which limits the amount of unbound etravirine available to enter the CNS. The objective of this study was to compare total and unbound etravirine concentrations in CSF with plasma concentrations and the in vitro median inhibitory concentration (IC50) for wild-type HIV (0.9 ng/mL).
Total and bound etravirine concentrations were measured in 17 CSF and plasma pairs by isotope-dilution liquid chromatography tandem mass spectroscopy, radioligand displacement and ultracentrifugation. Unbound etravirine concentrations were calculated from the bound fraction. The dynamic range of the assay was 7.8–2000 (plasma) and 0.78–200 (CSF) ng/mL.
Subjects were mostly middle-aged (median 43 years) white (78%) men (89%). All CSF etravirine concentrations were above the limit of quantification. Total and unbound median etravirine concentrations in CSF were 9.5 (IQR 6.4, 26.4) and 0.13 (IQR 0.08, 0.27) ng/mL, respectively. Etravirine was 96% (IQR 94.5, 97.2) protein bound in plasma and 98.4% (IQR 97.8, 98.8) in CSF. Total etravirine in CSF was 4.3% (IQR 3, 5.9) of total and 101% (IQR 76, 160) of unbound etravirine in plasma. There were no significant correlations between unbound etravirine concentrations and concentrations of albumin in plasma or CSF. Unbound etravirine concentrations in CSF did not reach the wild-type IC50 in any of the specimens.
Unbound etravirine may not achieve optimal concentrations to inhibit HIV replication in the CNS.
HIV; antiretroviral therapy; central nervous system; CNS; protein binding; CSF
According to the multi-process theory of prospective memory (ProM), time-based tasks rely more heavily on strategic processes dependent on prefrontal systems than do event-based tasks. Given the prominent frontostriatal pathophysiology of HIV infection, one would expect HIV-infected individuals to demonstrate greater deficits in time-based versus event-based ProM. However, the two prior studies examining this question have produced variable results. We evaluated this hypothesis in 143 individuals with HIV infection and 43 demographically similar seronegative adults (HIV−) who completed the research version of the Memory for Intentions Screening Test, which yields parallel subscales of time- and event-based ProM. Results showed main effects of HIV serostatus and cue type, but no interaction between serostatus and cue. Planned pair-wise comparisons showed a significant effect of HIV on time-based ProM and a trend-level effect on event-based ProM that was driven primarily by the subset of participants with HIV-associated neurocognitive disorders. Nevertheless, time-based ProM was more strongly correlated with measures of executive functions, attention/working memory, and verbal fluency in HIV-infected persons. Although HIV-associated deficits in time- and event-based ProM appear to be of comparable severity, the cognitive architecture of time-based ProM may be more strongly influenced by strategic monitoring and retrieval processes.
AIDS dementia complex; Episodic memory; Executive functions; Neuropsychological assessment
HIV-associated neurocognitive disorders remain common despite use of potent antiretroviral therapy (ART). Ongoing viral replication due to poor distribution of antivirals into the CNS may increase risk for HIV-associated neurocognitive disorders. This study's objective was to determine penetration of a commonly prescribed antiretroviral drug, efavirenz, into CSF.
CHARTER is an ongoing, North American, multicentre, observational study to determine the effects of ART on HIV-associated neurological disease. Single random plasma and CSF samples were drawn within 1 h of each other from subjects taking efavirenz between September 2003 and July 2007. Samples were assayed by HPLC or HPLC/mass spectrometry with detection limits of 39 ng/mL (plasma) and <0.1 ng/mL (CSF).
Eighty participants (age 44 ± 8 years; 79 ± 15 kg; 20 females) had samples drawn 12.5 ± 5.4 h post-dose. The median efavirenz concentrations after a median of 7 months [interquartile range (IQR) 2–17] of therapy were 2145 ng/mL in plasma (IQR 1384–4423) and 13.9 ng/mL in CSF (IQR 4.1–21.2). The CSF/plasma concentration ratio from paired samples drawn within 1 h of each other was 0.005 (IQR 0.0026–0.0076; n = 69). The CSF/IC50 ratio was 26 (IQR 8–41) using the published IC50 for wild-type HIV (0.51 ng/mL). Two CSF samples had concentrations below the efavirenz IC50 for wild-type HIV.
Efavirenz concentrations in the CSF are only 0.5% of plasma concentrations but exceed the wild-type IC50 in nearly all individuals. Since CSF drug concentrations reflect those in brain interstitial fluids, efavirenz reaches therapeutic concentrations in brain tissue.
CNS; pharmacology; non-nucleoside reverse transcriptase inhibitors
Both family history of dementia (FHD) and lower levels of
Aβ-42 are indepentently associated with worse neurocognitive
functioning in HIV-infected patients.
To examine the relationships between cerebrospinal fluid (CSF)
Aβ-42 and FHD with HIV-associated neurocognitive disorders
One hundred eighty-three HIV+ adults underwent
neuropsychological and neuromedical assessments, and determination of CSF
Aβ-42 concentration and FHD (defined as a self-reported first or
second-degree relative with a dementia diagnosis). Univariate analyses and
multivariable logistic regressions were used.
FHD was not associated with HAND (p = 0.24);
however, CSF Aβ-42 levels were lower (p =
0.03) in the HAND group, but were not associated with FHD
(p = 0.89). Multivariable models showed a main
effect of CSF Aβ-42 (p = 0.03) and a
trend-level (p = 0.06) interaction between FHD and
CSF Aβ-42, such that lower CSF Aβ-42 was associated with
HAND in those with FHD (p < 0.01) compared to those
without FHD (p = 0.83). An analysis in those with
follow-up data showed that higher baseline CSF Aβ-42 was associated
with lower risk of neurocognitive decline (p =
0.02). While we did not find an FHD X CSF Aβ-42 interaction
(p = 0.83), when analyses were stratified by
FHD, lower CSF Aβ-42 was associated at the trend-level with
neurocognitive decline in the FHD group (p = 0.08)
compared to the no FHD group (p = 0.15).
FHD moderates the relationship between of CSF Aβ-42 and HAND.
The findings highlight the complexities in interpreting the relationships
between biomarkers of age-related neurodegeneration and HAND.
HIV; dementia; biomarkers; cerebrospinal fluid; family history; neurocognitive impairment
Healthy Zambian adults (N = 324) were evaluated to determine to what degree a Western neuropsychological (NP) test battery, with African American norms adjusted for age, gender, and education could be used in healthy Zambians, including 157 (48.46%) men and 167 (51.54%) women with an average age of 38.48 (SD = 12.80) years and an average education level of 11.02 (SD = 2.58) years. The NP battery included tests of attention/working memory, executive function, verbal fluency, processing speed, verbal and visual episodic memory, and fine motor skills. The Zambian Achievement Test (ZAT) and the U.S. Wide Range Achievement Test-4 (WRAT-4) reading subtest also were administered to assess literacy and quality of education. Similar to findings in Western countries, the Zambian results show substantial age and education effects on most tests and smaller, less consistent effects of gender. Beyond the basic demographic effects, urban/rural background had small effects on some cognitive variables, and the ZAT (but not WRAT-4) reading level was a robust predictor of performance on many NP tests, even when other background characteristics were controlled. Women in the United States tend to outperform men on tests of processing speed and episodic memory, Zambian women showed modest but statistically significant disadvantages versus their male counterparts. The results show that tests developed in the United States may be used in Zambia, but development and use of local cultural norms remains very important and is a must. New demographically corrected norms were developed for the cohort that was examined.
neuropsychological tests; neuropsychological performance; U.S. norms; Zambia; African Americans; cross-cultural; Zambian norms
We report the first association to our knowledge between a mitochondrial DNA (mtDNA) haplogroup and neurocognitive impairment (NCI) in an admixed Hispanic subgroup of CNS HIV Antiretroviral Therapy Effects Research. mtDNA haplogroup B may be a susceptibility factor for NCI among human immunodeficiency virus-infected persons of admixed Hispanic ancestry.
Background. Neurocognitive impairment (NCI) remains an important complication in persons infected with human immunodeficiency virus (HIV). Ancestry-related mitochondrial DNA (mtDNA) haplogroups have been associated with outcomes of HIV infection and combination antiretroviral therapy (CART), and with neurodegenerative diseases. We hypothesize that mtDNA haplogroups are associated with NCI in HIV-infected adults and performed a genetic association study in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) cohort.
Methods. CHARTER is an observational study of ambulatory HIV-infected adults. Haplogroups were assigned using mtDNA sequence, and principal components were derived from ancestry-informative nuclear DNA variants. Outcomes were cross-sectional global deficit score (GDS) as a continuous measure, GDS impairment (GDS ≥ 0.50), and HIV-associated neurocognitive disorder (HAND) using international criteria. Multivariable models were adjusted for comorbidity status (incidental vs contributing), current CART, plasma HIV RNA, reading ability, and CD4 cell nadir.
Results. Haplogroups were available from 1027 persons; median age 43 years, median CD4 nadir 178 cells/mm3, 72% on CART, and 46% with HAND. The 102 (9.9%) persons of genetically determined admixed Hispanic ancestry had more impairment by GDS or HAND than persons of European or African ancestry (P < .001 for all). In multivariate models including persons of admixed Hispanic ancestry, those with haplogroup B had lower GDS (β = −0.34; P = .008) and less GDS impairment (odds ratio = 0.16; 95% confidence interval, .04, .63; P = .009) than other haplogroups. There were no significant haplogroup associations among persons of European or African ancestry.
Conclusions. In these mostly CART-treated persons, mtDNA haplogroup B was associated with less NCI among persons of genetically determined Hispanic ancestry. mtDNA variation may represent an ancestry-specific factor influencing NCI in HIV-infected persons.
HIV; AIDS; cognitive disorders; DNA, mitochondrial
Cognitive impairment (CI) and major depressive disorder (MDD) remain prevalent in treated HIV-1 disease; however, the pathogenesis remains elusive. A possible contributing mechanism is immune-mediated degradation of tryptophan (TRP) via the kynurenine (KYN) pathway, resulting in decreased production of serotonin and accumulation of TRP degradation products. We explored the association of these biochemical pathways and their relationship with CI and MDD in HIV-positive (HIV+) individuals.
In a cross-sectional analysis, concentrations of neopterin (NEO), tumor necrosis factor-alpha, TRP, KYN, KYN/TRP ratio, phenylalanine (PHE), tyrosine (TYR), PHE/TYR ratio, and nitrite were assessed in the cerebrospinal fluid (CSF) and plasma of HIV+ (n = 91) and HIV-negative (HIV−) individuals (n = 66). CI and MDD were assessed via a comprehensive neuropsychological test battery. A Global Deficit Score ≥0.5 was defined as CI. Nonparametric statistical analyses included Kruskal–Wallis and Mann–Whitney U tests, and multivariate logistic regression.
Following Bonferroni correction, NEO concentrations were found to be greater in CSF and TRP concentration was found to be lower in the plasma of HIV+ versus HIV− individuals, including a subgroup of aviremic (defined as HIV-1 RNA <50 cps/mL) HIV+ participants receiving antiretroviral therapy (n = 44). There was a nonsignificant trend toward higher KYN/TRP ratios in plasma in the HIV+ group (P = 0.027; Bonferroni corrected α = 0.0027). In a logistic regression model, lower KYN/TRP ratios in plasma were associated with CI and MDD in the overall HIV+ group (P = 0.038 and P = 0.063, respectively) and the aviremic subgroup (P = 0.066 and P = 0.027, respectively), though this observation was not statistically significant following Bonferroni correction (Bonferroni corrected α = 0.0031).
We observed a trend toward lower KYN/TRP ratios in aviremic HIV+ patients with CI and MDD.
HIV; cognitive impairment; depression; tryptophan; kynurenine; IDO
Findings on the nervous system complications of HIV disease and their impact on people living with HIV continue to accumulate. New reports at the 17th Conference on Retroviruses and Opportunistic Infections this year confirmed that HIV-associated neurocognitive disorders (HAND) are common, even among effectively treated individuals. Risk of HAND correlated with nadir CD4+ cell counts and with cerebrospinal fluid (CSF) viral loads that were at least as high as plasma viral loads. Other new data regarding risk factors for HAND implicated vascular disease, apolipoprotein E and mannose binding lectin genotypes, reduced resting cerebral blood flow, and HIV mutants that cause macrophages to shed the HIV gp120 protein. Two analyses linked worse neurocognitive performance to use of efavirenz, raising concerns about neurotoxicity. Analyses comparing differences in estimated distribution of antiretroviral drugs into the central nervous system (CNS) to neurocognitive outcomes using the 2008 version of the CNS penetration-effectiveness (CPE) ranking system did not support a hypothesis of neurotoxicity but did have mixed results, some supporting a benefit and some supporting no effect. Of note, a revised version of the CPE ranking system was presented that was more strongly associated with CSF viral loads than the 2008 version. Reports also estimated that primary CSF virologic failure occurs in 3% to 10% of treated individuals, although the clinical consequences of this remain uncertain. New data on common coinfections in people with HIV identified that a specific strain of Treponema pallidum may be more neurovirulent than other strains, that hepatitis C virus Core protein may be neurotoxic, and that hepatitis B virus may replicate in the nervous system. The extensive data presented will inform new research and clinical decisions in the coming year.
CSF HIV escape is a recently recognised phenomenon that suggests that despite suppressive treatment, HIV RNA may be detected in the CNS compartment in some individuals. In rare cases this is associated with clinical neurological disease, while in most cases, neurological consequences are not apparent. Attempts at characterising the biological substrates of CSF escape and further investigating the neurological consequences need to be made to better understand the implications of this condition for the HIV cure agenda as well as for clinical outcomes. The Global CSF HIV-1 Escape Consortium meeting, convened by the US National Institute of Mental Health, was a first step to gather investigators from diverse sites to discuss opportunities for future collaborative work on this emerging issue. To better understand CSF HIV escape and allow cross-site data reconciliation, it will be useful to reach a consensus set of definitions of the distinct forms of CSF escape, without which concerted cross-site efforts are difficult.
HIV-associated neurocognitive disorders (HAND) persist despite combination antiretroviral therapy (cART), supporting the need to better understand HIV neuropathogenesis. Magnetic resonance spectroscopy (MRS) of the brain has demonstrated abnormalities in HIV-infected individuals despite cART. We examined the associations between MRS metabolites and selected cerebrospinal fluid (CSF) biomarkers reflecting monocyte/macrophage activation and chemotaxis.
A multicenter cross-sectional study involving five sites in the United States was conducted. The following CSF biomarkers were measured: soluble CD14 (sCD14), monocyte chemotactic protein 1 (MCP-1), interferon inducible protein 10 (IP-10), and stromal cell derived growth factor 1 alpha (SDF-1α). The following MRS metabolites were measured from basal ganglia (BG), frontal white matter (FWM) and frontal gray matter (FGM): N-acetyl-aspartate (NAA), Myo-inositol (MI), Choline (Cho), and Creatine (Cr). CSF biomarkers were compared to absolute MRS metabolites as well as metabolite/Cr ratios using linear regression.
83 HIV-infected individuals were included, 78% on cART and 37% with HAND. The most robust positive correlations were between MCP-1 and Cho in BG (R2 0.179, p<0.001) as well as MCP-1 and MI in FWM (R2 0.137, p=0.002). Higher Cr levels in FWM were associated with MCP-1 (R2 0. 075, p=0.01) and IP-10 (R2 0.106, p=0.003). Comparing biomarkers to MRS metabolite/Cr ratios impacted some relationships, e.g., higher sCD14 levels were associated with lower Cho/Cr ratios in FGM (R2 0.224, p<0.001), although higher MCP-1 levels remained associated with Cho/Cr in BG.
These findings provide evidence that monocyte activation and chemotaxis continue to contribute to HIV-associated brain abnormalities in cART-treated individuals.
To design effective eradication strategies, it may be necessary to target HIV reservoirs in anatomic compartments other than blood. This study examined HIV RNA rebound following interruption of antiretroviral therapy (ART) in blood and cerebrospinal fluid (CSF) to determine whether the central nervous system (CNS) might serve as an independent source of resurgent viral replication.
Paired blood and CSF samples were collected longitudinally from 14 chronically HIV-infected individuals undergoing ART interruption. HIV env (C2-V3), gag (p24) and pol (reverse transcriptase) were sequenced from cell-free HIV RNA and cell-associated HIV DNA in blood and CSF using the Roche 454 FLX Titanium platform. Comprehensive sequence and phylogenetic analyses were performed to search for evidence of unique or differentially represented viral subpopulations emerging in CSF supernatant as compared with blood plasma.
Using a conservative definition of compartmentalization based on four distinct statistical tests, nine participants presented a compartmentalized HIV RNA rebound within the CSF after interruption of ART, even when sampled within 2 weeks from viral rebound. The degree and duration of viral compartmentalization varied considerably between subjects and between time-points within a subject. In 10 cases, we identified viral populations within the CSF supernatant at the first sampled time-point after ART interruption, which were phylogenetically distinct from those present in the paired blood plasma and mostly persisted over time (when longitudinal time-points were available). Our data suggest that an independent source of HIV RNA contributes to viral rebound within the CSF after treatment interruption. The most likely source of compartmentalized HIV RNA is a CNS reservoir that would need to be targeted to achieve complete HIV eradication.
central nervous system; HIV reservoir; ART interruption; viral rebound.
There has been a reduction in the most severe cases of HIV-associated neurocognitive disorders (HAND) with advances in antiretroviral treatment (ART). But the prevalence of milder forms of HAND still remains high. Data from systematically conducted studies on the effects of ART on cognition are scanty in India where HIV-1 clade C is prevalent. The purpose of the present study was to assess the effect of antiretroviral therapy in HIV seropositive (HIV+) individuals (n = 92) with CD4 cell counts < 200 cells/mm3. Overall and domain-specific levels of cognitive functioning were determined using a locally-recruited normative sample and change in neurocognitive functioning at the one-year follow-up visit was analyzed. Results revealed cognitive impairment in 44.6% of the HIV+ group at baseline. At the one-year follow-up, the group showed significant improvement in the Learning domain (p<0.05). HIV+ individuals showing improvement in the global cognitive scores had a significantly lower baseline CD4 cell count compared to others. Overall, the degree of improvement associated with the magnitude of rise in CD4 suggests the possibility that early, mild subclinical declines may also benefit from treatment.
HIV; neurocognitive impairment; antiretroviral therapy; CD4 count; HIV RNA
We examined the association between physical activity (PA), neurocognitive impairment (NCI), and instrumental activities of daily living (IADLs) among older HIV+ persons. One hundred older HIV+ adults completed the International Physical Activity Questionnaire (IPAQ), a neurocognitive battery, and IADL scale. Higher levels of moderate PA were associated with lower odds of NCI (p=0.01), even when covariates were modeled. The association between moderate PA and NCI was driven by executive function (p=0.04). Higher levels of moderate PA were also associated with lower odds of IADL Dependence (p = 0.03), although this fell to a trend (p = 0.08) when including covariates. Follow-up analysis showed those with both NCI and IADL Dependence had lower moderate PA than those with neither (p=0.03). While these cross-sectional findings suggest PA is associated with better neurocognitive and everyday functioning in older HIV+ adults, longitudinal studies utilizing objective PA methods are needed to evaluate directionality and mechanisms.
Exercise; Aging; HIV/AIDS; Cognition; IADLs; Physical Therapy
Methamphetamine dependence is a common comorbid condition among people living with HIV, and may exacerbate HIV-associated neurocognitive disorders. Animal models of neuroAIDS suggest that the gp120 protein may also cause cognitive impairment. The present work evaluated the separate and combined effects of HIV/gp120 and methamphetamine on learning and executive functions in both humans and transgenic mice. Human participants were grouped by HIV serostatus (HIV+ or HIV−) and lifetime methamphetamine dependence (METH+ or METH−). A neurocognitive test battery included domain-specific assessments of learning and executive functions. Mice (gp120+ and gp120−) were exposed to either a methamphetamine binge (METH+) or saline (METH−), then tested in the attentional-set-shifting task to assess learning and executive functions. In humans, HIV status was associated with significant impairments in learning, but less so for executive functions. The frequency of learning impairments varied between groups, with the greatest impairment observed in the HIV+/METH+ group. In mice, gp120 expression was associated with impairments in learning but not reversal learning (executive component). The greatest proportion of mice that failed to complete the task was observed in the gp120+/METH+ group, suggesting greater learning impairments. Our cross-species study demonstrated that HIV in humans and gp120 in mice impaired learning, and that a history of methamphetamine exposure increased the susceptibility to HIV-associated neurocognitive deficits in both species. Finally, the similar pattern of results in both species suggest that the gp120 protein may contribute to HIV-associated learning deficits in humans.
Although milder forms of HIV-associated neurocognitive disorder (HAND) remain prevalent, a correlation to neuronal injury has not been established in patients on antiretroviral therapy (ART). We examined the relationship between mild HAND and CSF neurofilament light protein (NFL), a biomarker of neuronal injury; and CSF neopterin, a biomarker of CNS immunoactivation, in virally suppressed patients on antiretroviral therapy (ART).
Design and Methods
We selected 99 subjects on suppressive ART followed longitudinally from the CNS HIV Anti-Retroviral Therapy Effects Research (CHARTER) study. Based on standardized comprehensive neurocognitive performance (NP) testing, subjects were classified as neurocognitively normal (NCN; n = 29) or impaired (NCI; n = 70). The NCI group included subjects with asymptomatic (ANI; n = 37) or mild (MND; n = 33) HAND. CSF biomarkers were analyzed on two occasions.
Geometric mean CSF neopterin was 25% higher in the NCI group (p = 0.04) and NFL and neopterin were significantly correlated within the NCI group (r = 0.30; p<0.001) but not in the NCN group (r = -0.13; p = 0.3). Additionally, a trend towards higher NFL was seen in the NCI group (p = 0.06).
Mild HAND was associated with increased intrathecal immune activation, and the correlation between neopterin and NFL found in NCI subjects indicates an association between neurocognitive impairment, CNS inflammation and neuronal damage. Together these findings suggest that NCI despite ART may represent an active pathological process within the CNS that needs further characterization in prospective studies.
HIV-associated brain injury persists despite antiretroviral therapy (cART), but contributing factors remain poorly understood. We postulated that inflammation-associated biomarkers will be associated with cerebral injury on proton magnetic resonance spectroscopy (MRS) in chronically HIV-infected subjects.
Five biomarkers were measured in 197 HIV-infected subjects: soluble CD14, MCP-1, IP-10, MIP-1β, and fractalkine. Levels of N-acetyl aspartate (NAA), Choline (Cho), Myoinositol (MI), Glutamate+Glutamine (Glx), and Creatine (Cr) were acquired in the midfrontal cortex (MFC), frontal white matter (FWM), and basal ganglia (BG). Predictive models were built via linear regression and the best models were chosen using the Akaike Information Criterion.
Increases in plasma or CSF MCP-1 were associated with lower NAA/Cr in the MFC and BG while metabolite changes in the FWM for NAA/Cr, GlxCr and Cho/Cr were explained almost exclusively by a single factor, sCD14. Plasma and CSF levels of this factor were also significantly associated with Glx/Cr in MFC and BG. Higher CSF FKN was associated with higher NAA/Cr in BG. Best predictors for higher Cho/Cr in BG and MFC were CSF sCD14 and CSF MIP-1β. Plasma and CSF IP-10 were only associated with Cho/Cr in MFC. Of the three models that simultaneously accounted for both plasma and CSF, there were more associations between CSF biomarkers and MRS metabolites.
Markers of inflammation and immune activation, in particular MCP-1 and sCD14, predominantly reflecting CNS sources, contribute to the persistence of brain injury in a metabolite and region dependent manner in chronically HIV-infected patients on stable cART.
HIV; AIDS; HIV-associated neurocognitive disorder; cerebrospinal fluid
Human immunodeficiency virus (HIV) and methamphetamine use commonly affect neurocognitive (NC) functioning. We evaluated the relationships between NC functioning and two fibroblast growth factors (FGFs) in volunteers who differed in HIV serostatus and methamphetamine dependence (MAD).
A total of 100 volunteers were categorized into four groups based on HIV serostatus and MAD in the prior year. FGF-1 and FGF-2 were measured in cerebrospinal fluid by enzyme-linked immunosorbent assays along with two reference biomarkers (monocyte chemotactic protein [MCP]-1 and neopterin). Comprehensive NC testing was summarized by global and domain impairment ratings.
Sixty-three volunteers were HIV+ and 59 had a history of MAD. FGF-1, FGF-2, and both reference biomarkers differed by HIV and MAD status. For example, FGF-1 levels were lower in subjects who had either HIV or MAD than in HIV− and MAD− controls (P=0.003). Multivariable regression identified that global NC impairment was associated with an interaction between FGF-1 and FGF-2 (model R2=0.09, P=0.01): higher FGF-2 levels were only associated with neurocognitive impairment among subjects who had lower FGF-1 levels. Including other covariates in the model (including antidepressant use) strengthened the model (model R2=0.18, P=0.004) but did not weaken the association with FGF-1 and FGF-2. Lower FGF-1 levels were associated with impairment in five of seven cognitive domains, more than FGF-2, MCP-1, or neopterin.
These findings provide in vivo support that HIV and MAD alter expression of FGFs, which may contribute to the NC abnormalities associated with these conditions. These cross-sectional findings cannot establish causality and the therapeutic benefits of recombinant FGF-1 need to be investigated.
biomarker; cerebrospinal fluid; fibroblast growth factor; HIV; methamphetamine; HIV-associated neurocognitive disorders; HAND; neurocognitive impairment
To identify prognostic surrogate markers for change in cognitive states of HIV-infected patients.
Longitudinal cerebrospinal fluid (CSF) samples were collected from 98 HIV+ patients identified by temporal change in cognitive states classified as normal, stably impaired, improving and worsening.
The metabolic composition of CSF was analysed using 1HNMR spectroscopy that focused on energy metabolites. Metabolic biomarkers for cognitive states were identified using multivariate partial least squares regression modelling of the acquired spectra, combined with nonparametric analyses of metabolites with clinical features.
Multivariate modelling and cross-validated recursive partitioning identified several energy metabolites that, when combined with clinical variables, classified patients based on change in neurocognitive states. Prognostic identification for worsening was achieved with four features that included no change in a detectable plasma viral load, elevated citrate and acetate; decreased creatine, to produce a model with a predictive accuracy of 92%, sensitivity of 88% and 96% specificity. Prognosis for improvement contained seven features that included first visit age less than 47 years, new or continued use of antiretrovirals, elevated glutamine and glucose; decreased myo-inositol, β-glucose and creatinine to generate a model with a predictive accuracy of 92%, sensitivity of 100% and specificity of 84%.
These CSF metabolic results suggest that worsening cognitive status in HIV-infected patients is associated with increased aerobic glycolysis, and improvements in cognitive status are associated with a shift to anaerobic glycolysis. Dietary, lifestyle and pharmacologic interventions that promote anaerobic glycolysis could protect the brain in setting of HIV infection with combined antiretroviral therapy.
brain energy metabolism; HIV; HIV-associated neurocognitive disorders; metabolomics
We tested our hypothesis that abdominal obesity when associated with increased levels of systemic and CNS immuno-inflammatory mediators contributes to neurocognitive impairment (NCI).
Six Academic Centers
152 patients with plasma HIV RNA <1,000copies/ml had clinical evaluations and cognitive function quantified by global deficit scores (GDS).
GDS, waist circumference (WC) and plasma IL-6, sCD163, and sCD14 and CSF sCD40L, sTNFrII, MCP-1, sICAM, and MMP-9.
WC and plasma IL-6 levels positively correlated with GDS; the WC correlation was strongest in the high tertile of IL-6 (rho=0.39, p=0.005). IL-6 correlated with GDS only if WC was ≥99cm. In the high tertile of CSF sCD40L, a biomarker of macrophage and microglial activation, the correlation of IL-6 to GDS was strongest (rho=0.60, p<0.0001). Across 3-5 visits within ±1year of the index visit, GDS remained worse in patients with IL-6 levels in the high-versus-low tertile (p=0.02). Path analysis to explore potential mediators of NCI produced a strong, integrated model for patients in the high CSF sCD40L tertile. In this model, WC affected GDS both directly and via a second path that was mediated by IL-6. Inclusion of plasma sCD14 levels strengthened the model. NCI was more common in men and for individuals with components of the metabolic syndrome.
NC function was significantly linked to abdominal obesity, systemic inflammation (high IL-6), and immune activation in plasma (high sCD14) and CSF (high sCD40L). Abdominal obesity, inflammation, and CNS immune activation are potential therapeutic targets for NCI in HIV+ patients.
Abdominal obesity; HIV Associated Neurocognitive Disorder; Inflammation and immune activation; Global deficit score; sCD40L; sCD14
HIV+ persons with co-occurring bipolar disorder (HIV+/BD+) have elevated rates of medication nonadherence. We conducted a 30-day randomized controlled trial of a two-way, text messaging system, iTAB (n = 25), compared to an active comparison (CTRL) (n = 25) to improve antiretroviral (ARV) and psychotropic (PSY) adherence and dose timing. Both groups received medication adherence psychoeducation and daily texts assessing mood. The iTAB group additionally received personalized medication reminder texts. Participants responded to over 90 % of the mood and adherence text messages. Mean adherence, as assessed via electronic monitoring caps, was high and comparable between groups for both ARV (iTAB 86.2 % vs. CTRL 84.8 %; p = 0.95, Cliff’s d = 0.01) and PSY (iTAB 78.9 % vs. CTRL 77.3 %; p = 0.43, Cliff’s d = −0.13) medications. However, iTAB participants took ARVs significantly closer to their intended dosing time than CTRL participants (iTAB: 27.8 vs. CTRL: 77.0 min from target time; p = 0.02, Cliff’s d = 0.37). There was no group difference on PSY dose timing. Text messaging interventions may represent a low-burden approach to improving timeliness of medication-taking behaviors among difficult-to-treat populations. The benefits of improved dose timing for long-term medication adherence require additional investigation.
Medication adherence; HIV/AIDS; Bipolar disorder; mHealth; Behavior modification; Randomized controlled trial; Intervention research
HIV-associated neurocognitive disorders (HAND) still occur in approximately 50% of HIV patients, and therapies to combat HAND progression are urgently needed. HIV proteins are released from infected cells and cause neuronal damage, possibly through mitochondrial abnormalities. Altered mitochondrial fission and fusion is implicated in several neurodegenerative disorders. Here, we hypothesized that mitochondrial fission/fusion may be dysregulated in neurons during HAND. We have identified decreased mitochondrial fission protein (dynamin 1-like; DNM1L) in frontal cortex tissues of HAND donors, along with enlarged and elongated mitochondria localized to the soma of damaged neurons. Similar pathology was observed in the brains of GFAP-gp120 tg mice. In vitro, recombinant gp120 decreased total and active DNM1L levels, reduced the level of Mitotracker staining, and increased extracellular acidification rate (ECAR) in primary neurons. DNM1L knockdown enhanced the effects of gp120 as measured by reduced Mitotracker signal in the treated cells. Interestingly, overexpression of DNM1L increased the level of Mitotracker staining in primary rat neurons and reduced neuroinflammation and neurodegeneration in the GFAP-gp120-tg mice. These data suggest that mitochondrial biogenesis dynamics are shifted towards mitochondrial fusion in brains of HAND patients and this may be due to gp120-induced reduction in DNM1L activity. Promoting mitochondrial fission during HIV infection of the CNS may restore mitochondrial biogenesis and prevent neurodegeneration.
HIV; mitochondria; fission/fusion; DNM1L; gp120; neurodegeneration; biogenesis