Integrating HCV testing with HIV programs improves hepatitis C outcomes in people who inject drugs: A cluster-randomized trial

BACKGROUND & AIMS

There have been calls to integrate HCV testing into existing services, including harm reduction and HIV prevention and treatment, but there are few empirical trials to date. We evaluated the impact of integrating HCV testing/education into integrated care centers (ICCs) delivering HIV services to people who inject drugs (PWID) across India, using a cluster-randomized trial.

METHODS

We compared ICCs with usual care in the PWID stratum (12 sites) of a 22-site cluster-randomized trial. In 6 sites, ICCs delivering HIV testing, harm reduction, other preventive services and linkage to HIV treatment were scaled from opioid agonist therapy centers and operated for 2 years. On-site rapid HCV antibody testing was integrated after 1 year. To assess impact, we conducted baseline and evaluation surveys using respondent-driven sampling (RDS) across the 12 sites (n = 11,993 recruited at baseline; n = 11,721 recruited at evaluation). The primary outcome was population-level self-reported HCV testing history.

RESULTS

At evaluation, HCV antibody prevalence ranged from 7.2-76.6%. Across 6 ICCs, 5,263 ICC clients underwent HCV testing, of whom 2,278 were newly diagnosed. At evaluation, PWID in ICC clusters were 4-fold more likely to report being tested for HCV than in usual care clusters, adjusting for baseline testing (adjusted prevalence ratio [aPR] 3.69; 95% CI 1.34-10.2). PWID in ICC clusters were also 7-fold more likely to be aware of their HCV status (aPR 7.11; 95% CI 1.14-44.3) and significantly more likely to initiate treatment (aPR 9.86; 95% CI 1.52-63.8).

CONCLUSIONS

We provide among the first empirical data supporting the integration of HCV testing into HIV/harm reduction services. To achieve elimination targets, programs will need to scale-up such venues to deliver comprehensive HCV services. CLINICALTRIALS.

GOV IDENTIFIER

NCT01686750.

LAY SUMMARY

Delivering hepatitis C virus (HCV) testing to people who inject drugs (PWID) in places where they also have access to HIV prevention and treatment services is an effective way to improve uptake of HCV testing among communities of PWID. To achieve the World Health Organization's ambitious elimination targets, integrated programs will need to be scaled up to deliver comprehensive HCV services.

Addressing the global burden of hepatitis B virus while developing long-acting injectables for the prevention and treatment of HIV

The first long-acting formulations of HIV drugs are undergoing regulatory review for use in maintenance of viral suppression in people with HIV. Although these novel drug formulations could contribute greatly to HIV treatment and prevention efforts, their lack of activity against hepatitis B virus (HBV) could limit their global impact, particularly in populations with high burdens of both HIV and HBV. An urgent need for greater investment in research and development of long-acting drugs with dual activity against HIV and HBV exists. Access to long-acting HIV drug formulations with dual activity against HBV would be transformative and have a great impact on efforts to prevent, treat, and eradicate both of these important global epidemics.

Consensus-based technical recommendations for clinical translation of renal ASL MRI

OBJECTIVES

This study aimed at developing technical recommendations for the acquisition, processing and analysis of renal ASL data in the human kidney at 1.5 T and 3 T field strengths that can promote standardization of renal perfusion measurements and facilitate the comparability of results across scanners and in multi-centre clinical studies.

METHODS

An international panel of 23 renal ASL experts followed a modified Delphi process, including on-line surveys and two in-person meetings, to formulate a series of consensus statements regarding patient preparation, hardware, acquisition protocol, analysis steps and data reporting.

RESULTS

Fifty-nine statements achieved consensus, while agreement could not be reached on two statements related to patient preparation. As a default protocol, the panel recommends pseudo-continuous (PCASL) or flow-sensitive alternating inversion recovery (FAIR) labelling with a single-slice spin-echo EPI readout with background suppression and a simple but robust quantification model.

DISCUSSION

This approach is considered robust and reproducible and can provide renal perfusion images of adequate quality and SNR for most applications. If extended kidney coverage is desirable, a 2D multislice readout is recommended. These recommendations are based on current available evidence and expert opinion. Nonetheless they are expected to be updated as more data become available, since the renal ASL literature is rapidly expanding.

Consensus-based technical recommendations for clinical translation of renal ASL MRI

Objectives

This study aimed at developing technical recommendations for the acquisition, processing and analysis of renal ASL data in the human kidney at 1.5 T and 3 T field strengths that can promote standardization of renal perfusion measurements and facilitate the comparability of results across scanners and in multi-centre clinical studies.

Methods

An international panel of 23 renal ASL experts followed a modified Delphi process, including on-line surveys and two in-person meetings, to formulate a series of consensus statements regarding patient preparation, hardware, acquisition protocol, analysis steps and data reporting.

Results

Fifty-nine statements achieved consensus, while agreement could not be reached on two statements related to patient preparation. As a default protocol, the panel recommends pseudo-continuous (PCASL) or flow-sensitive alternating inversion recovery (FAIR) labelling with a single-slice spin-echo EPI readout with background suppression and a simple but robust quantification model.

Discussion

This approach is considered robust and reproducible and can provide renal perfusion images of adequate quality and SNR for most applications. If extended kidney coverage is desirable, a 2D multislice readout is recommended. These recommendations are based on current available evidence and expert opinion. Nonetheless they are expected to be updated as more data become available, since the renal ASL literature is rapidly expanding.

Electronic supplementary material

The online version of this article (10.1007/s10334-019-00800-z) contains supplementary material, which is available to authorized users.

Cerebral perfusion changes in presymptomatic genetic frontotemporal dementia: a GENFI study

Genetic forms of frontotemporal dementia are most commonly due to mutations in three genes, C9orf72, GRN or MAPT, with presymptomatic carriers from families representing those at risk. While cerebral blood flow shows differences between frontotemporal dementia and other forms of dementia, there is limited evidence of its utility in presymptomatic stages of frontotemporal dementia. This study aimed to delineate the cerebral blood flow signature of presymptomatic, genetic frontotemporal dementia using a voxel-based approach. In the multicentre GENetic Frontotemporal dementia Initiative (GENFI) study, we investigated cross-sectional differences in arterial spin labelling MRI-based cerebral blood flow between presymptomatic C9orf72, GRN or MAPT mutation carriers (n = 107) and non-carriers (n = 113), using general linear mixed-effects models and voxel-based analyses. Cerebral blood flow within regions of interest derived from this model was then explored to identify differences between individual gene carrier groups and to estimate a timeframe for the expression of these differences. The voxel-based analysis revealed a significant inverse association between cerebral blood flow and the expected age of symptom onset in carriers, but not non-carriers. Regions included the bilateral insulae/orbitofrontal cortices, anterior cingulate/paracingulate gyri, and inferior parietal cortices, as well as the left middle temporal gyrus. For all bilateral regions, associations were greater on the right side. After correction for partial volume effects in a region of interest analysis, the results were found to be largely driven by the C9orf72 genetic subgroup. These cerebral blood flow differences first appeared approximately 12.5 years before the expected symptom onset determined on an individual basis. Cerebral blood flow was lower in presymptomatic mutation carriers closer to and beyond their expected age of symptom onset in key frontotemporal dementia signature regions. These results suggest that arterial spin labelling MRI may be a promising non-invasive imaging biomarker for the presymptomatic stages of genetic frontotemporal dementia.

Serum neurofilament light chain in genetic frontotemporal dementia: a longitudinal, multicentre cohort study

BACKGROUND

Neurofilament light chain (NfL) is a promising blood biomarker in genetic frontotemporal dementia, with elevated concentrations in symptomatic carriers of mutations in GRN, C9orf72, and MAPT. A better understanding of NfL dynamics is essential for upcoming therapeutic trials. We aimed to study longitudinal NfL trajectories in people with presymptomatic and symptomatic genetic frontotemporal dementia.

METHODS

We recruited participants from 14 centres collaborating in the Genetic Frontotemporal Dementia Initiative (GENFI), which is a multicentre cohort study of families with genetic frontotemporal dementia done across Europe and Canada. Eligible participants (aged ≥18 years) either had frontotemporal dementia due to a pathogenic mutation in GRN, C9orf72, or MAPT (symptomatic mutation carriers) or were healthy at-risk first-degree relatives (either presymptomatic mutation carriers or non-carriers), and had at least two serum samples with a time interval of 6 months or more. Participants were excluded if they had neurological comorbidities that were likely to affect NfL, including cerebrovascular events. We measured NfL longitudinally in serum samples collected between June 8, 2012, and Dec 8, 2017, through follow-up visits annually or every 2 years, which also included MRI and neuropsychological assessments. Using mixed-effects models, we analysed NfL changes over time and correlated them with longitudinal imaging and clinical parameters, controlling for age, sex, and study site. The primary outcome was the course of NfL over time in the various stages of genetic frontotemporal dementia.

FINDINGS

We included 59 symptomatic carriers and 149 presymptomatic carriers of a mutation in GRN, C9orf72, or MAPT, and 127 non-carriers. Nine presymptomatic carriers became symptomatic during follow-up (so-called converters). Baseline NfL was elevated in symptomatic carriers (median 52 pg/mL [IQR 24-69]) compared with presymptomatic carriers (9 pg/mL [6-13]; p<0·0001) and non-carriers (8 pg/mL [6-11]; p<0·0001), and was higher in converters than in non-converting carriers (19 pg/mL [17-28] vs 8 pg/mL [6-11]; p=0·0007; adjusted for age). During follow-up, NfL increased in converters (b=0·097 [SE 0·018]; p<0·0001). In symptomatic mutation carriers overall, NfL did not change during follow-up (b=0·017 [SE 0·010]; p=0·101) and remained elevated. Rates of NfL change over time were associated with rate of decline in Mini Mental State Examination (b=-94·7 [SE 33·9]; p=0·003) and atrophy rate in several grey matter regions, but not with change in Frontotemporal Lobar Degeneration-Clinical Dementia Rating scale score (b=-3·46 [SE 46·3]; p=0·941).

INTERPRETATION

Our findings show the value of blood NfL as a disease progression biomarker in genetic frontotemporal dementia and suggest that longitudinal NfL measurements could identify mutation carriers approaching symptom onset and capture rates of brain atrophy. The characterisation of NfL over the course of disease provides valuable information for its use as a treatment effect marker.

FUNDING

ZonMw and the Bluefield project.

Reduced acquisition time PET pharmacokinetic modelling using simultaneous ASL-MRI: proof of concept

Pharmacokinetic modelling on dynamic positron emission tomography (PET) data is a quantitative technique. However, the long acquisition time is prohibitive for routine clinical use. Instead, the semi-quantitative standardised uptake value ratio (SUVR) from a shorter static acquisition is used, despite its sensitivity to blood flow confounding longitudinal analysis. A method has been proposed to reduce the dynamic acquisition time for quantification by incorporating cerebral blood flow (CBF) information from arterial spin labelling (ASL) magnetic resonance imaging (MRI) into the pharmacokinetic modelling. In this work, we optimise and validate this framework for a study of ageing and preclinical Alzheimer's disease. This methodology adapts the simplified reference tissue model (SRTM) for a reduced acquisition time (RT-SRTM) and is applied to [¹⁸F]-florbetapir PET data for amyloid-β quantification. Evaluation shows that the optimised RT-SRTM can achieve amyloid burden estimation from a 30-min PET/MR acquisition which is comparable with the gold standard SRTM applied to 60 min of PET data. Conversely, SUVR showed a significantly higher error and bias, and a statistically significant correlation with tracer delivery due to the influence of blood flow. The optimised RT-SRTM produced amyloid burden estimates which were uncorrelated with tracer delivery indicating its suitability for longitudinal studies.

In vivo demonstration of microscopic anisotropy in the human kidney using multidimensional diffusion MRI

PURPOSE

To demonstrate the feasibility of multidimensional diffusion MRI to probe and quantify microscopic fractional anisotropy (µFA) in human kidneys in vivo.

METHODS

Linear tensor encoded (LTE) and spherical tensor encoded (STE) renal diffusion MRI scans were performed in 10 healthy volunteers. Respiratory triggering and image registration were used to minimize motion artefacts during the acquisition. Kidney cortex-medulla were semi-automatically segmented based on fractional anisotropy (FA) values. A model-free analysis of LTE and STE signal dependence on b-value in the renal cortex and medulla was performed. Subsequently, µFA was estimated using a single-shell approach. Finally, a comparison of conventional FA and µFA is shown.

RESULTS

The hallmark effect of µFA (divergence of LTE and STE signal with increasing b-value) was observed in all subjects. A statistically significant difference between LTE and STE signal was found in the cortex and medulla, starting from b = 750 s/mm2 and b = 500 s/mm2 , respectively. This difference was maximal at the highest b-value sampled (b = 1000 s/mm2 ) which suggests that relatively high b-values are required for µFA mapping in the kidney compared to conventional FA. Cortical and medullary µFA were, respectively, 0.53 ± 0.09 and 0.65 ± 0.05, both respectively higher than conventional FA (0.19 ± 0.02 and 0.40 ± 0.02).

CONCLUSION

The feasibility of combining LTE and STE diffusion MRI to probe and quantify µFA in human kidneys is demonstrated for the first time. By doing so, we show that novel microstructure information-not accessible by conventional diffusion encoding-can be probed by multidimensional diffusion MRI. We also identify relevant technical limitations that warrant further development of the technique for body MRI.

White matter hyperintensities in progranulin-associated frontotemporal dementia: A longitudinal GENFI study

Frontotemporal dementia (FTD) is a heterogeneous group of neurodegenerative disorders with both sporadic and genetic forms. Mutations in the progranulin gene (GRN) are a common cause of genetic FTD, causing either a behavioural presentation or, less commonly, language impairment. Presence on T2-weighted images of white matter hyperintensities (WMH) has been previously shown to be more commonly associated with GRN mutations rather than other forms of FTD. The aim of the current study was to investigate the longitudinal change in WMH and the associations of WMH burden with grey matter (GM) loss, markers of neurodegeneration and cognitive function in GRN mutation carriers.

336 participants in the Genetic FTD Initiative (GENFI) study were included in the analysis: 101 presymptomatic and 32 symptomatic GRN mutation carriers, as well as 203 mutation-negative controls. 39 presymptomatic and 12 symptomatic carriers, and 73 controls also had longitudinal data available. Participants underwent MR imaging acquisition including isotropic 1 mm T1-weighted and T2-weighted sequences. WMH were automatically segmented and locally subdivided to enable a more detailed representation of the pathology distribution. Log-transformed WMH volumes were investigated in terms of their global and regional associations with imaging measures (grey matter volumes), biomarker concentrations (plasma neurofilament light chain, NfL, and glial fibrillary acidic protein, GFAP), genetic status (TMEM106B risk genotype) and cognition (tests of executive function).

Analyses revealed that WMH load was higher in both symptomatic and presymptomatic groups compared with controls and this load increased over time. In particular, lesions were seen periventricularly in frontal and occipital lobes, progressing to medial layers over time. However, there was variability in the WMH load across GRN mutation carriers – in the symptomatic group 25.0% had none/mild load, 37.5% had medium and 37.5% had a severe load – a difference not fully explained by disease duration. GM atrophy was strongly associated with WMH load both globally and in separate lobes, and increased WMH burden in the frontal, periventricular and medial regions was associated with worse executive function. Furthermore, plasma NfL and to a lesser extent GFAP concentrations were seen to be associated with increased lesion burden. Lastly, the presence of the homozygous TMEM106B rs1990622 TT risk genotypic status was associated with an increased accrual of WMH per year.

In summary, WMH occur in GRN mutation carriers and accumulate over time, but are variable in their severity. They are associated with increased GM atrophy and executive dysfunction. Furthermore, their presence is associated with markers of WM damage (NfL) and astrocytosis (GFAP), whilst their accrual is modified by TMEM106B genetic status. WMH load may represent a target marker for trials of disease modifying therapies in individual patients but the variability across the GRN population would prevent use of such markers as a global outcome measure across all participants in a trial.

Correlates of hepatitis C viral clustering among people who inject drugs in Baltimore

This study examines correlates of hepatitis C virus (HCV) genetic clustering among community-recruited people who inject drugs enrolled in the AIDS Linked to the IntraVenous Experience cohort in Baltimore between 1988 and 1989. HCV RNA was extracted and the core/envelope-1 region was sequenced. Clusters were identified from maximum likelihood trees with 1000 bootstrap replicates using a 70% aLRT and a 4% genetic-distance threshold in Cluster Picker. Overall, 46% of participants were in a cluster, including 122 genotype-1a and 36 genotype-1b clusters with an average of 2-3 genetically linked HCV infections. The largest cluster consists of 9 participants. In univariable analysis, black race (PR = 1.66 [95% CI: 1.12-2.45]), age <35 years (PR = 1.18 [95% CI: 1.02-1.37]), and injection drug use of cocaine alone (PR = 1.30 [95% CI: 1.02-1.65]) were significantly associated with being in a cluster. Conversely, a history of medication-associated treatment (MAT) was negatively associated with being in a cluster (PR = 0.82 [95% CI: 0.71-0.95]). In multivariable analysis, black race (APR = 1.62 [95% CI: 1.11-2.38]) remained independently associated being in a cluster while MAT (APR = 0.85 [95% CI: 0.74-0.99]) remained negatively associated with clustering. Our findings suggest strong locally-propagated transmission networks during the early epidemic that was driven by younger PWID. In light of the current opioid epidemic in the US, these findings suggest an urgent need for preventive interventions to mitigate the growth of large HCV transmission networks.

An Education and Field Experience Program to Increase Detection of Human Immunodeficiency Virus and Hepatitis C Virus

BACKGROUND

Baltimore is an urban center that has been highly impacted by human immunodeficiency virus (HIV) and hepatitis C virus (HCV); however, many individuals are unaware of their HIV and/or HCV status. In 2013, the Johns Hopkins Center for AIDS Research (CFAR) developed Generation Tomorrow, an HIV and HCV education, testing, and counseling program with community input and collaboration.

OBJECTIVES

The aims of Generation Tomorrow are to increase HIV and HCV awareness and detection in Baltimore and engage the next generation of health professionals (students) and community members (peers) in HIV and HCV outreach services.

METHODS

The Generation Tomorrow educational component includes formal HIV and HCV testing and counselling training, and a lecture series for students and peers. The participants then engage in field assignments and outreach events with Johns Hopkins associated programs or community-based organizations.

RESULTS

Generation Tomorrow trained 71 students and peers in three cohorts, 70% of whom reported that they planned to stay in HIV- and/or HCV-related work. From October 2014 to May 2015, which represents the first year that Generation Tomorrow ran with the full academic calendar, Generation Tomorrow students and peers worked with partner organizations to conduct 1,104 HIV rapid antibody tests and found 19 individuals (1.72%) to be HIV positive. Additionally, 778 HCV rapid antibody tests were conducted and 175 individuals (22.5%) were HCV antibody positive.

CONCLUSIONS

Generation Tomorrow has been successful in engaging students and community peers in HIV and HCV education, testing, and counseling, and has documented HIV and HCV positivity rates well above general community prevalence.

Hippocampal subfield volumes and pre-clinical Alzheimer's disease in 408 cognitively normal adults born in 1946

BACKGROUND

The human hippocampus comprises a number of interconnected histologically and functionally distinct subfields, which may be differentially influenced by cerebral pathology. Automated techniques are now available that estimate hippocampal subfield volumes using in vivo structural MRI data. To date, research investigating the influence of cerebral β-amyloid deposition-one of the earliest hypothesised changes in the pathophysiological continuum of Alzheimer's disease-on hippocampal subfield volumes in cognitively normal older individuals, has been limited.

METHODS

Using cross-sectional data from 408 cognitively normal individuals born in mainland Britain (age range at time of assessment = 69.2-71.9 years) who underwent cognitive assessment, 18F-Florbetapir PET and structural MRI on the same 3 Tesla PET/MR unit (spatial resolution 1.1 x 1.1 x 1.1. mm), we investigated the influences of β-amyloid status, age at scan, and global white matter hyperintensity volume on: CA1, CA2/3, CA4, dentate gyrus, presubiculum and subiculum volumes, adjusting for sex and total intracranial volume.

RESULTS

Compared to β-amyloid negative participants (n = 334), β-amyloid positive participants (n = 74) had lower volume of the presubiculum (3.4% smaller, p = 0.012). Despite an age range at scanning of just 2.7 years, older age at time of scanning was associated with lower CA1 (p = 0.007), CA4 (p = 0.004), dentate gyrus (p = 0.002), and subiculum (p = 0.035) volumes. There was no evidence that white matter hyperintensity volume was associated with any subfield volumes.

CONCLUSION

These data provide evidence of differential associations in cognitively normal older adults between hippocampal subfield volumes and β-amyloid deposition and, increasing age at time of scan. The relatively selective effect of lower presubiculum volume in the β-amyloid positive group potentially suggest that the presubiculum may be an area of early and relatively specific volume loss in the pathophysiological continuum of Alzheimer's disease. Future work using higher resolution imaging will be key to exploring these findings further.

Effect of Fluorinert on the Histological Properties of Formalin-Fixed Human Brain Tissue

Fluorinert (perfluorocarbon) represents an inexpensive option for minimizing susceptibility artifacts in ex vivo brain MRI scanning, and provides an alternative to Fomblin. However, its impact on fixed tissue and histological analysis has not been rigorously and quantitatively validated. In this study, we excised tissue blocks from 2 brain regions (frontal pole and cerebellum) of 5 formalin-fixed specimens (2 progressive supranuclear palsy cases, 3 controls). We excised 2 blocks per region per case (20 blocks in total), one of which was subsequently immersed in Fluorinert for a week and then returned to a container with formalin. The other block from each region was kept in formalin for use as control. The tissue blocks were then sectioned and histological analysis was performed on each, including routine stains and immunohistochemistry. Visual inspection of the stained histological sections by an experienced neuropathologist through the microscope did not reveal any discernible differences between any of the samples. Moreover, quantitative analysis based on automated image patch classification showed that the samples were almost indistinguishable for a state-of-the-art classifier based on a deep convolutional neural network. The results showed that Fluorinert has no effect on subsequent histological analysis of the tissue even after a long (1 week) period of immersion, which is sufficient for even the lengthiest scanning protocols.

Tractography-based parcellation does not provide strong evidence of anatomical organisation within the thalamus

Connectivity-based parcellation of subcortical structures using diffusion tractography is now a common paradigm in neuroscience. These analyses often imply voxel-level specificity of connectivity, and the formation of compact, spatially coherent clusters is often taken as strong imaging-based evidence for anatomically distinct subnuclei in an individual. In this study, we demonstrate that internal structure in diffusion anisotropy is not necessary for a plausible parcellation to be obtained, by spatially permuting diffusion parameters within the thalami and repeating the parcellation. Moreover, we show that, in a winner-takes-all paradigm, most voxels receive the same label before and after this shuffling process-a finding that is stable across image acquisitions and tractography algorithms. We therefore suggest that such parcellations should be interpreted with caution.

Hepatitis C Elimination in People With HIV Is Contingent on Closing Gaps in the HIV Continuum

BACKGROUND

Bolstered by the high efficacy of hepatitis C virus (HCV) treatment, the World Health Organization has called for HCV elimination by 2030. People with HIV (PWH) have been identified as a population in which elimination should be prioritized.

METHODS

We examined progress in HCV elimination through the HCV care continuum among patients infected with HIV/HCV receiving HIV care at Johns Hopkins Hospital in Baltimore, Maryland, United States. Patients with HIV care visits in at least 2 consecutive years were followed through December 15, 2018, for referral to HCV care, treatment initiation, and cure.

RESULTS

Among 593 HIV/HCV-coinfected individuals, 547 (92%) were referred for HCV care, 517 (87%) were evaluated for HCV treatment, 457 (77%) were prescribed HCV treatment, 426 (72%) initiated treatment, and 370 (62%) achieved HCV cure. In multivariable analysis, advanced liver disease (hazard ratio [HR], 1.48; 95% confidence interval [CI], 1.17-1.88) remained significantly positively associated with HCV treatment initiation. Conversely, being insured by state Medicaid (HR, 0.75; 95% CI, 0.61-0.92), having an HIV RNA >400 copies/mL (HR, 0.29; 95% CI, 0.18-0.49), and having missed 1%-24% (HR, 0.72; 95% CI, 0.54-0.97), 25%-49% (HR, 0.66; 95% CI, 0.49-0.89), and ≥50% of HIV care visits (HR, 0.39; 95% CI, 0.25-0.60) were significantly negatively associated with HCV treatment initiation.

CONCLUSIONS

HCV infection can be eliminated in PWH. However, HCV elimination requires unrestricted access to HCV treatment and improved methods of retaining people in medical care.

Automated Brainstem Segmentation Detects Differential Involvement in Atypical Parkinsonian Syndromes

Objective

Brainstem segmentation has been useful in identifying potential imaging biomarkers for diagnosis and progression in atypical parkinsonian syndromes (APS). However, the majority of work has been performed using manual segmentation, which is time consuming for large cohorts.

Methods

We investigated brainstem involvement in APS using an automated method. We measured the volume of the medulla, pons, superior cerebellar peduncle (SCP) and midbrain from T1-weighted MRIs in 67 patients and 42 controls. Diagnoses were corticobasal syndrome (CBS, n = 14), multiple system atrophy (MSA, n = 16: 8 with parkinsonian syndrome, MSA-P; 8 with cerebellar syndrome, MSA-C), progressive supranuclear palsy with a Richardson’s syndrome (PSP-RS, n = 12), variant PSP (n = 18), and APS not otherwise specified (APS-NOS, n = 7).

Results

All brainstem regions were smaller in MSA-C (19–42% volume difference, p < 0.0005) and in both PSP groups (18–33%, p < 0.0005) than in controls. MSA-P showed lower volumes in all regions except the SCP (15–26%, p < 0.0005). The most affected region in MSA-C and MSA-P was the pons (42% and 26%, respectively), while the most affected regions in both the PSP-RS and variant PSP groups were the SCP (33% and 23%, respectively) and midbrain (26% and 24%, respectively). The brainstem was less affected in CBS, but nonetheless, the pons (14%, p < 0.0005), midbrain (14%, p < 0.0005) and medulla (10%, p = 0.001) were significantly smaller in CBS than in controls. The brainstem was unaffected in APS-NOS.

Conclusion

Automated methods can accurately quantify the involvement of brainstem structures in APS. This will be important in future trials with large patient numbers where manual segmentation is unfeasible.

Quantification of cerebral perfusion and cerebrovascular reserve using Turbo-QUASAR arterial spin labeling MRI

Purpose

To compare cerebral blood flow (CBF) and cerebrovascular reserve (CVR) quantification from Turbo‐QUASAR (quantitative signal targeting with alternating radiofrequency labeling of arterial regions) arterial spin labeling (ASL) and single post‐labeling delay pseudo‐continuous ASL (PCASL).

Methods

A model‐based method was developed to quantify CBF and arterial transit time (ATT) from Turbo‐QUASAR, including a correction for magnetization transfer effects caused by the repeated labeling pulses. Simulations were performed to assess the accuracy of the model‐based method. Data from an in vivo experiment conducted on a healthy cohort were retrospectively analyzed to compare the CBF and CVR (induced by acetazolamide) measurement from Turbo‐QUASAR and PCASL on the basis of global and regional differences. The quality of the two ASL data sets was examined using the coefficient of variation (CoV).

Results

The model‐based method for Turbo‐QUASAR was accurate for CBF estimation (relative error was 8% for signal‐to‐noise ratio = 5) in simulations if the bolus duration was known. In the in vivo experiment, the mean global CVR estimated by Turbo‐QUASAR and PCASL was between 63% and 64% and not significantly different. Although global CBF values of the two ASL techniques were not significantly different, regional CBF differences were found in deep gray matter in both pre‐ and postacetazolamide conditions. The CoV of Turbo‐QUASAR data was significantly higher than PCASL.

Conclusion

Both ASL techniques were effective for quantifying CBF and CVR, despite the regional differences observed. Although CBF estimated from Turbo‐QUASAR demonstrated a higher variability than PCASL, Turbo‐QUASAR offers the advantage of being able to measure and control for variation in ATT.

Overlapping epidemics of alcohol and illicit drug use among HCV-infected persons who inject drugs

BACKGROUND

Alcohol use in people who inject drugs (PWID) with hepatitis C virus (HCV) infection accelerates liver disease progression. This paper describes the prevalence and associated correlates of alcohol use among HCV antibody positive PWID.

METHODS

In a large cohort of HCV antibody positive PWID (N = 1623) followed from 2005 to 2013, we characterized alcohol use using the AUDIT-C. We used multivariable logistic regression with generalized estimated equations to examine socio-demographic, clinical, and substance use correlates of alcohol use.

RESULTS

At their initial visit, 41% reported no, 21% reported moderate, and 38% reported heavy alcohol use. The odds of moderate and heavy alcohol use increased with greater intensity of substance use represented by a composite summary variable which ranged from 0 to 3 substances (street-acquired prescription drugs, non-injection cocaine/heroin, and injection drugs) used. Compared to those who used no drugs, those who used 3 substances had 3.71 odds (95% CI: 3.07-4.48) of moderate alcohol use and 3.65 odds (95% CI: 3.20-4.16) of heavy alcohol use.

CONCLUSIONS

The prevalence of moderate/heavy alcohol use is high among HCV antibody positive PWID and occurs frequently in combination with other drug use. This may contribute to progressive liver fibrosis thus limiting the gains achieved from HCV cure. Public health interventions need to address the overlapping epidemics of HCV, alcohol use, and other substance use in this population.

HIV and the liver

Among individuals with HIV infection, liver disease remains an important cause of morbidity and mortality, even with the availability of agents that cure hepatitis C infection and suppress hepatitis B replication. The causes of liver disease are multifaceted and continue to evolve as the population ages and new etiologies arise. Nonalcoholic fatty liver disease and nonalcoholic steatohepatitis and hepatitis viruses such as A, D, and E have emerged even as hepatitis C has receded. Newer antiretroviral agents may increase risk of weight gain and subsequent fatty infiltration, and prior use of nucleotide-based therapies may continue to impact liver health. Several barriers including economics, social stigma, and psychiatric disease impact identification of liver disease, as well as management and treatment interventions. Hepatocellular carcinoma is emerging as a more common and late-diagnosed complication in those with HIV infection and liver disease.

Incidental findings on brain imaging and blood tests: results from the first phase of Insight 46, a prospective observational substudy of the 1946 British birth cohort

OBJECTIVE

To summarise the incidental findings detected on brain imaging and blood tests during the first wave of data collection for the Insight 46 study.

DESIGN

Prospective observational sub-study of a birth cohort.

SETTING

Single-day assessment at a research centre in London, UK.

PARTICIPANTS

502 individuals were recruited from the MRC National Survey of Health and Development (NSHD), the 1946 British birth cohort, based on pre-specified eligibility criteria; mean age was 70.7 (SD: 0.7) and 49% were female.

OUTCOME MEASURES

Data regarding the number and types of incidental findings were summarised as counts and percentages, and 95% confidence intervals were calculated.

RESULTS

93.8% of participants completed a brain scan (n=471); 4.5% of scanned participants had a pre-defined reportable abnormality on brain MRI (n=21); suspected vascular malformations and suspected intracranial mass lesions were present in 1.9% (n=9) and 1.5% (n=7) respectively; suspected cerebral aneurysms were the single most common vascular abnormality, affecting 1.1% of participants (n=5), and suspected meningiomas were the most common intracranial lesion, affecting 0.6% of participants (n=3); 34.6% of participants had at least one abnormality on clinical blood tests (n=169), but few reached the prespecified threshold for urgent action (n=11).

CONCLUSIONS

In older adults, aged 69-71 years, potentially serious brain MRI findings were detected in around 5% of participants, and clinical blood test abnormalities were present in around one third of participants. Knowledge of the expected prevalence of incidental findings in the general population at this age is useful in both research and clinical settings.