Tanja Su

Multivariate normative comparison, a novel method for more reliably detecting cognitive impairment in HIV infection.

Objective:The objective of this study is to assess whether multivariate normative comparison (MNC) improves detection of HIV-1-associated neurocognitive disorder (HAND) as compared with Frascati and Gisslén criteria. Methods:One-hundred and three HIV-1-infected men with suppressed viremia on combination antiretroviral therapy (cART) for at least 12 months and 74 HIV-uninfected male controls (comparable regarding age, ethnicity, sexual orientation, premorbid intelligence and educational level), aged at least 45 years, underwent neuropsychological assessment covering six cognitive domains (fluency, attention, information processing speed, executive function, memory, and motor function). Frascati and Gisslén criteria were applied to detect HAND. Next, MNC was performed to compare the cognitive scores of each HIV-positive individual against the cognitive scores of the control group. Results:HIV-infected men showed significantly worse performance on the cognitive domains of attention, information processing speed and executive function compared with HIV-uninfected controls. HAND by Frascati criteria was highly prevalent in HIV-infected [48%; 95% confidence interval (95% CI) 38–58] but nearly equally so in HIV-uninfected men (36%; 95% CI 26–48), confirming the low specificity of this method. Applying Gisslén criteria, HAND-prevalence was reduced to 5% (95% CI 1–9) in HIV-infected men and to 1% (95% CI 1–3) among HIV-uninfected controls, indicating better specificity but reduced sensitivity. MNC identified cognitive impairment in 17% (95% CI 10–24) of HIV-infected men and in 5% (95% CI 0–10) of the control group (P = 0.02, one-tailed), showing an optimal balance between sensitivity and specificity. Conclusion:Prevalence of cognitive impairment in HIV-1-infected men with suppressed viremia on cART estimated by MNC was much higher than that estimated by Gisslén criteria, while the false positive rate was greatly reduced compared with the Frascati criteria. Video abstract:http://links.lww.com/QAD/A633

White matter hyperintensities in relation to cognition in HIV-infected men with sustained suppressed viral load on combination antiretroviral therapy

Objectives:The objective of this study was to assess whether HIV-infected patients on long-term successful combination antiretroviral therapy (cART) have more extensive white matter hyperintensities (WMH) of presumed vascular origin compared with uninfected controls and whether these intensities are associated with cognitive impairment. Furthermore, we explored potential determinants of increased WMH load long-term suppressed HIV infection. Design:A cross-sectional comparison of WMH in an observational cohort. Methods:Clinical, cognitive, and MRI data were collected from 103 middle-aged, aviremic HIV-infected men on cART, and 70 HIV-uninfected, otherwise similar controls. In the MRI data, WMH load was quantified by automated approaches and qualitatively reviewed by an experienced neuroradiologist using the Fazekas scale. Results:HIV-infected men had an increased WMH load. Among HIV-infected patients, increased WMH load was independently associated with older age, higher DBP, higher D-dimer levels, and longer time spent with a CD4+ cell count below 500 cells/&mgr;l. HIV-associated cognitive deficits were associated with increased WMH load. Conclusions:WMH are more extensive and associated with cognitive deficits in middle-aged, aviremic cART-treated HIV-infected men. The extent of WMH load was associated with both cardiovascular risk factors and past immune deficiency. As cognitive impairment in these same patients is also associated with these risk factors, this may suggest that in the setting of HIV, WMH, and cognitive deficits share a common cause. This supports the importance of optimizing cardiovascular risk management, and early, effective treatment of HIV infection.

White matter structure alterations in HIV-1-infected men with sustained suppression of viraemia on treatment.

Objective:Cognitive impairment is highly prevalent in HIV-1-infected (HIV+) patients, despite adequate suppression of viral replication by combination antiretroviral therapy (cART). Cerebral white matter structure alterations are often associated with cognitive impairment and have commonly been reported in the natural course of HIV infection. However, the existence of these alterations in adequately treated HIV+ patients remains unknown, as well as its possible association with cognitive impairment. Design:We used diffusion tensor imaging (DTI) to investigate whether white matter structure alterations exist in HIV+ patients with sustained suppressed viral replication on cART, and if such alterations are related to HIV-associated cognitive deficits. Methods:We compared 100 aviraemic HIV+ men on cART with 70 HIV-uninfected, otherwise comparable men. Clinical and neuropsychological assessments were performed. From DTI data, white matter fractional anisotropy and mean diffusion were calculated. Subsequently, tract-based spatial statistics (TBSS) was performed, with and without masking out white matter lesions. Results:HIV+ patients showed diffuse white matter structure alterations as compared with HIV-uninfected controls, observed as widespread decreased fractional anisotropy and an increased mean diffusion. These white matter structure alterations were associated with the number of years spent with a CD4+ cell count below 500 cells/&mgr;l, but not with HIV-associated cognitive deficits. Conclusion:Cerebral white matter structure alterations are found in middle-aged HIV+ men with sustained suppression of viraemia on cART, and may result from periods with immune deficiency when viral toxicity and host-inflammatory responses were at their peak. These white matter structure alterations were not associated with the observed subtle HIV-associated cognitive deficits. Video abstract:https://youtu.be/Dg3AOLNxVVo

Determinants of reduced cognitive performance in HIV-1-infected middle-aged men on combination antiretroviral therapy

Objective:The spectrum of risk factors for HIV-associated cognitive impairment is likely very broad and includes not only HIV/antiretroviral therapy-specific factors but also other comorbid conditions. The purpose of this current study was to explore possible determinants for decreased cognitive performance. Design and methods:Neuropsychological assessment was performed on 103 HIV-1-infected men with suppressed viraemia on combination antiretroviral therapy for at least 12 months and 74 HIV-uninfected highly similar male controls, all aged at least 45 years. Cognitive impairment and cognitive performance were determined by multivariate normative comparison (MNC). Determinants of decreased cognitive performance and cognitive impairment were investigated by linear and logistic regression analysis, respectively. Results:Cognitive impairment as diagnosed by MNC was found in 17% of HIV-1-infected men. Determinants for decreased cognitive performance by MNC as a continuous variable included cannabis use, history of prior cardiovascular disease, impaired renal function, diabetes mellitus type 2, having an above normal waist-to-hip ratio, presence of depressive symptoms, and lower nadir CD4+ cell count. Determinants for cognitive impairment, as dichotomized by MNC, included cannabis use, prior cardiovascular disease, impaired renal function, and diabetes mellitus type 2. Conclusion:Decreased cognitive performance probably results from a multifactorial process, including not only HIV-associated factors, such as having experienced more severe immune deficiency, but also cardiovascular/metabolic factors, cannabis use, and depressive symptoms.

Gray and White Matter Abnormalities in Treated Human Immunodeficiency Virus Disease and Their Relationship to Cognitive Function

Background Long-term comorbidities such as cognitive impairment remain prevalent in otherwise effectively treated people living with human immunodeficiency virus (HIV). We investigate the relationship between cognitive impairment and brain structure in successfully treated patients using multimodal neuroimaging from the Comorbidity in Relation to AIDS (COBRA) cohort. Methods Cognitive function, brain tissue volumes, and white matter microstructure were assessed in 134 HIV-infected patients and 79 controls. All patients had suppressed plasma HIV RNA at cohort entry. In addition to comprehensive voxelwise analyses of volumetric and diffusion tensor imaging, we used an unsupervised machine learning approach to combine cognitive, diffusion, and volumetric data, taking advantage of the complementary information they provide. Results Compared to the highly comparable control group, cognitive function was impaired in 4 of the 6 cognitive domains tested (median global T-scores: 50.8 vs 54.2; P < .001). Patients had lower gray but not white matter volumes, observed principally in regions where structure generally did not correlate with cognitive function. Widespread abnormalities in white matter microstructure were also seen, including reduced fractional anisotropy with increased mean and radial diffusivity. In contrast to the gray matter, these diffusion abnormalities correlated with cognitive function. Multivariate neuroimaging analysis identified a neuroimaging phenotype associated with poorer cognitive function, HIV infection, and systemic immune activation. Conclusions Cognitive impairment, lower gray matter volume, and white matter microstructural abnormalities were evident in HIV-infected individuals despite fully suppressive antiretroviral therapy. White matter abnormalities appear to be a particularly important determinant of cognitive dysfunction seen in well-treated HIV-infected individuals.

Cerebral blood flow and cognitive function in HIV-infected men with sustained suppressed viremia on combination antiretroviral therapy

Objective: To assess if HIV-infected patients on long-term successful combination antiretroviral therapy show cerebral blood flow (CBF) alterations in comparison with HIV-uninfected, otherwise similar controls. To explore whether such alterations are associated with HIV-associated cognitive impairment and to explore potential determinants of CBF alterations in HIV. Design: Cross-sectional comparison of CBF in an observational cohort study. Methods: Clinical, cognitive and MRI data of 100 middle-aged aviremic HIV-infected men on combination antiretroviral therapy and 69 HIV-uninfected controls were collected and compared. From pseudocontinuous arterial spin labeling MRI data, CBF-maps were calculated. The associations of mean gray matter CBF with clinical and cognitive parameters were explored in regression models, followed by a spatial delineation in a voxel-based analysis. Results: CBF was decreased in HIV-infected patients compared with HIV-uninfected controls (P = 0.02), adjusted for age, ecstasy use and waist circumference. Spatially distinct and independent effects of total gray matter volume and HIV-serostatus on CBF were found. Within the HIV-infected group, decreased CBF was associated with increased triglyceride levels (P = 0.005) and prior clinical AIDS (P = 0.03). No association between CBF and cognitive impairment was found. Conclusion: Decreased CBF was observed among HIV-infected patients, which was associated with both vascular risk factors as well as with measures of past immune deficiency. These results provide support for increased vascular disease in HIV-infected patients as represented by hemodynamic alteration, but without overt cognitive consequences within the current cohort of patients on long-term successful treatment.

Reliable dual tensor model estimation in single and crossing fibers based on jeffreys prior

Purpose This paper presents and studies a framework for reliable modeling of diffusion MRI using a data-acquisition adaptive prior. Methods Automated relevance determination estimates the mean of the posterior distribution of a rank-2 dual tensor model exploiting Jeffreys prior (JARD). This data-acquisition prior is based on the Fisher information matrix and enables the assessment whether two tensors are mandatory to describe the data. The method is compared to Maximum Likelihood Estimation (MLE) of the dual tensor model and to FSL’s ball-and-stick approach. Results Monte Carlo experiments demonstrated that JARD’s volume fractions correlated well with the ground truth for single and crossing fiber configurations. In single fiber configurations JARD automatically reduced the volume fraction of one compartment to (almost) zero. The variance in fractional anisotropy (FA) of the main tensor component was thereby reduced compared to MLE. JARD and MLE gave a comparable outcome in data simulating crossing fibers. On brain data, JARD yielded a smaller spread in FA along the corpus callosum compared to MLE. Tract-based spatial statistics demonstrated a higher sensitivity in detecting age-related white matter atrophy using JARD compared to both MLE and the ball-and-stick approach. Conclusions The proposed framework offers accurate and precise estimation of diffusion properties in single and dual fiber regions.

Novel method for more reliably estimating the burden of cognitive impairment in HIV

* Educational level was defined using the International Standard Classification of Education (ISCED) 2011. # Depressive symptoms were assessed using the Beck Depression Inventory (BDI). Novel Method for More Reliably Estimating the Burden of Cognitive Impairment in HIV T. Su1, J. Schouten, G.J. Geurtsen1, F.W. Wit1,2, I.G. Stolte3, M. Prins1,3, P. Portegies1,4, M.W.A. Caan1, P. Reiss1,2,5, C.B. Majoie1, B. Schmand1 , on behalf of the AGEhIV Cohort Study group 1 Academic Medical Center 2 Amsterdam Institute for Global Health and Development 3 Public Health Service Amsterdam 4 Onze Lieve Vrouwe Gasthuis 5 HIV Monitoring Foundation; Amsterdam, the Netherlands

High Cellular Monocyte Activation in People Living With Human Immunodeficiency Virus on Combination Antiretroviral Therapy and Lifestyle-Matched Controls Is Associated With Greater Inflammation in Cerebrospinal Fluid

Abstract Background Increased monocyte activation and intestinal damage have been shown to be predictive for the increased morbidity and mortality observed in treated people living with human immunodeficiency virus (PLHIV). Methods A cross-sectional analysis of cellular and soluble markers of monocyte activation, coagulation, intestinal damage, and inflammation in plasma and cerebrospinal fluid (CSF) of PLHIV with suppressed plasma viremia on combination antiretroviral therapy and age and demographically comparable HIV-negative individuals participating in the Comorbidity in Relation to AIDS (COBRA) cohort and, where appropriate, age-matched blood bank donors (BBD). Results People living with HIV, HIV-negative individuals, and BBD had comparable percentages of classical, intermediate, and nonclassical monocytes. Expression of CD163, CD32, CD64, HLA-DR, CD38, CD40, CD86, CD91, CD11c, and CX3CR1 on monocytes did not differ between PLHIV and HIV-negative individuals, but it differed significantly from BBD. Principal component analysis revealed that 57.5% of PLHIV and 62.5% of HIV-negative individuals had a high monocyte activation profile compared with 2.9% of BBD. Cellular monocyte activation in the COBRA cohort was strongly associated with soluble markers of monocyte activation and inflammation in the CSF. Conclusions People living with HIV and HIV-negative COBRA participants had high levels of cellular monocyte activation compared with age-matched BBD. High monocyte activation was predictive for inflammation in the CSF.