The Florey Institute of Neuroscience and Mental Health

Author Of 1 Presentation

Genetics and Epigenetics Oral Presentation

PS08.03 - Deconvolution of epigenetic profiles reveals blood cell-specific pathways associated with early stage Multiple Sclerosis in the AusImmune Study

Speakers
Presentation Number
PS08.03
Presentation Topic
Genetics and Epigenetics
Lecture Time
13:15 - 13:27

Abstract

Background

Genomic DNA methylation is a modifiable epigenetic mechanism that exhibits wide-spread variation among blood cell types. Methylation can influence disease phenotypes via modulating the effects of genetic and environmental factors on gene expression. Changes in methylation at the human leukocyte antigen gene (HLA-DRB1) have been previously associated with multiple sclerosis (MS) in both T lymphocytes and monocytes. This association is influenced by the well-established MS haplotype at this locus.

Objectives

To further characterise the cell-specific methylation profiles of MS by performing an epigenome-wide association study (EWAS) incorporating a statistical deconvolution of whole blood data

Methods

This was a case-control design involving subjects from the AusImmune Study. Specifically included were, 221 MS patients at first demyelination diagnosis and 468 population-based controls matched for age, sex and residential location. DNA methylation derived from whole blood was measured using Illumina EPIC arrays. EWAS analysis was performed using the ChAMP program. Cell deconvolution analysis was performed using the CellDMC function of the EpiDISH program . This method adjusts methylation levels by variation in blood cell proportions among subjects and can effectively estimate cell-specific methylation profiles without the need to do cell sorting. Gene set enrichment analysis (GSEA) was performed using the ToppGene program. All tests were assessed for statistical significance using a false discovery rate (FDR) of 0.05.

Results

The top differentially methylated region (DMR) was HLA-DRB1, which included both hypo and hyper methylation loci (PFDR<0.05). The underlying HLA-DRB1 haplotype was strongly associated with these DMRs. Deconvolution analyses showed that the HLA-DRB1 signal specifically originated from T cells and monocytes, which is consistent with previous findings. Interestingly, cell-specific GSEA revealed associations with pathways related to axonal guidance signalling, specifically in T cells, natural killer (NK) cells, and B cells. In particular, epigenetic variation in the Netrin-1 signalling pathway in both NK and B cells was associated with MS in this cohort (PFDR<0.05). Netrin‐1, is an axon guidance protein that reduces serum levels of pro-inflammatory mediators and stabilizes the blood-brain barrier limiting the entrance of immune cells into the central nervous system. These pathways were not detected in whole blood methylation analyses, highlighting the importance of the cellular deconvolution approach.

Conclusions

These results provide provisional evidence that epigenetic variation in axonal signalling pathways is associated with early-stage MS in a cell-dependent manner. If validated, these findings might help guide future efforts in epigenetic medicine for MS.

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Author Of 4 Presentations

Clinical Trials Poster Presentation

P0185 - A phase II randomised controlled trial of a cognitive behavioral therapy intervention for depression in those newly diagnosed with MS (ID 1578)

Speakers
Presentation Number
P0185
Presentation Topic
Clinical Trials

Abstract

Background

Depression is a serious and co-morbid condition of MS. Up to 50% of individuals with MS experience clinically significant levels of depressive symptoms at any one time (Arnett et al., 2008). Depression and anxiety are especially high after diagnosis (Giordano et al., 2011; Kiropoulos et al., 2016) with 36% of individuals found to report high levels of depressive symptoms in the first years after diagnosis (Jensens et al., 2003). Cogntitive Behaviour Therapy (CBT) has shown to be effective in reducing symptoms of depression in those with MS (Kiropoulos et al., 2016) with the current study being the first RCT examining the effectiveness of a tailored cognitive behavioural therapy (CBT) intervention, compared to a supportive listening (SL) intervention, for depression in those who have been newly diagnosed with MS (within 5 years of having received a MS diagnosis).

Objectives

To assess efficacy of an early tailored CBT intervention, compared to SL, in producing significant and clinically meaningful reductions in: 1) depressive symptoms; 2) anxiety symptoms and 3) MS-related concerns (such as fatigue, sleep disturbance, pain impact). And to: 4) increase physical and mental health related quality of life, MS illness acceptance, social support, coping and resilience; and 5) to assess cost-effectiveness of providing the CBT intervention. An additional aim is to measure and examine changes in levels of cytokines before and after the interventions.

Methods

This is a two arm, parallel group, active comparator, assessor blinded RCT with the primary site being the Royal Melbourne Hospital. Recruitment is also being undertaken from three major MS clinics located in Melbourne, Victoria. 60 participants are being randomly allocated to a tailored CBT(n=30) or SL (n=30) intervention. 8 x 1 hour interventions will be delivered over 8 weeks by clinical psychologists for both treatment arms. Self-report and clinician data is and will be collected at pre, post and 3 mth follow up time points. Eligibility criteria includes mild to moderately depressed individuals newly diagnosed (within first 5 years of diagnosis) with MS. Exclusion criteria includes gross cognitive impairment; serious psychological disorder; delirium; undertaking psychological treatment for depression; unable to speak or read English.

Results

Preliminary results will be presented for the primary outcome which is the level of clinically significant change of 10 points or more on the BDI-2 at post therapy, secondary outcomes which are the level of depression at 3 mths and level of anxiety at post-assessment and tertiary outcomes which are the level of anxiety at 3 mths follow up, pain and fatigue impact, MS illness acceptance, sleep quality, coping, social support, resilience at post and 3 mth follow up.

Conclusions

Conclusions will be provided relating to the effectiveness of the CBT intervention in the treatment of depression in individuals newly diagnosed with MS.

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Imaging Poster Presentation

P0582 - High resolution functional mapping of upper and lower limb sensorimotor function in minimally disabled people with multiple sclerosis using 7T MRI (ID 1050)

Speakers
Presentation Number
P0582
Presentation Topic
Imaging

Abstract

Background

In multiple sclerosis (MS) upper and lower limbs can be affected, but impairments only moderately relate to each other. Previous motor task studies have focussed predominantly on imaging hand function at clinical field strengths, preventing the detection of subtle changes and differentiation of mechanisms underlying subtle motor impairment.

Objectives

To investigate functional brain changes related to upper and/or lower limb motor task performance in minimally disabled MS patients using ultra-high field MRI.

Methods

Twenty-eight MS patients and seventeen healthy controls underwent visually-guided force-matching fMRI tasks using either hand or foot. Task performance (force error and lag) and activation level during upper and lower limb movements were compared between groups. Correlations were assessed between task activation and behavioural performance.

Results

During lower limb force tracking, MS patients showed significantly (p<0.01) longer lag, higher force error, higher primary motor and premotor cortex activation and lower cerebellar Crus I/II activation, compared to controls. No differences were seen in upper limb performance or activation. Upper and lower limb task performance was related to the level of activation in cerebellar, visual and motor areas in MS patients.

Conclusions

Altered lower limb movements and brain activation with preserved upper limb function and activation in minimally disabled patients suggests partially divergent functional mechanisms underlying upper and lower limb disability.

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Imaging Poster Presentation

P0626 - Quantitative Susceptibility Mapping at 7 Tesla detects ongoing active lesions in relapse-free RRMS patients (ID 1540)

Abstract

Background

Microglia are iron-rich cells, found surrounding multiple sclerosis (MS) lesions in areas of active inflammation. Quantitative Susceptibility Mapping (QSM) can detect this increased iron and thus could be a novel MRI biomarker for microglia-associated inflammation in the brain. The proportion of patients with active inflammation is currently unknown, as is the proportion of MS lesions seen on conventional MRI sequences that are active across patients. Ultra-high field MRI (7 Tesla +) provides superior signal to noise and susceptibility contrast making it the optimal method for detecting iron in MS lesions and tracking active inflammation.

Objectives

To compare the number of lesions with positive QSM signal indicating active inflammation with lesion size and number in patients with relapsing-remitting MS (RRMS) using 7T MRI.

Methods

21 people with RRMS (mean ± SD age = 42 ± 11 yrs; sex: 2m/19f; mean ± SD disease duration = 5.5 ± 3.2 yrs; all EDSS < 4; no relapses in previous 12 months) were scanned using MP2RAGE anatomical and multi-echo gradient echo sequences on a Siemens 7T MAGNETOM MRI scanner. MP2RAGE was used to identify lesions and then co-registered to QSM (calculated from gradient echo phase images using an in-house pipeline). The number of lesions with an average QSM value over 0 (QSM+), indicating the presence of iron associated with active inflammation, were compared to the total number and total volume (log10 transformed) of lesions across patients using linear regression.

Results

The number of lesions in patients ranged from 3 to 92 (mean ± SD = 33 ± 25) and volumes ranged from 26 to 14505 mm3 (mean ± SD = 2554 ± 3445 mm3). Across all patients, the average proportion of QSM+ lesions was 0.61 (95% CI = 0.50-0.72, R2=0.87, p<0.0001), and for each log10 cubic millimeter change in the lesion volume, there were an additional 15 QSM+ lesions (95% CI = 7.0-24, R2=0.43, p=0.0012). There were no associations between the proportion of QSM+ lesions and any disease or demographic variables.

Conclusions

Irrespective of disease severity or duration, the proportion of QSM+ lesions was highly consistent. Based on the assumption that QSM+ lesions are undergoing active inflammation, our results indicate that around ~60% of lesions in RRMS patients could be active.

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Neuropsychology and Cognition Poster Presentation

P0831 - Validation of longitudinal reaction time trajectories in multiple sclerosis using the MSReactor computerized battery and latent class analysis. (ID 1660)

Speakers
Presentation Number
P0831
Presentation Topic
Neuropsychology and Cognition

Abstract

Background

Longitudinal cognitive trajectories in MS are heterogenous and difficult to measure. Computerised tests designed to screen broad cognitive domains may be a reliable method to detect discrete trajectories of cognitive performance

Objectives

To validate a latent class model to identify trajectories of reaction time change in people with relapsing remitting MS (pwRRMS).

Methods

The MSReactor computerised cognitive battery is a self-administered, online set of reaction time tasks assessing psychomotor function (PsychoM), visual attention (VisAtt) and working memory (WorkingM). Participants completed both 6-monthly in-clinic testing and additional remote testing. Latent class analysis was used to model the longitudinal reaction times and identify discrete cognitive trajectories within the heterogeneous data. We applied a cross validation method to confirm the optimal models for all three reaction time tasks. Briefly, the cohort was split into training and test sets (50:50) and the mean root mean square error (RMSE) calculated for the difference between training and test trajectories calculated at each day of follow up, over 100 repetitions. To determine the minimum number of tests required to reliably classify an individual into a longitudinal trajectory the dataset for each task was reduced to 3, 4 and 5 tests per participant and classification compared to the complete dataset.

Results

We included 478 pwRRMS who had completed at least 3 MSReactor tests over a minimum of 30 days follow up. In total, 3846 individual tests were included in each model (median tests/participant=5 (range 3-332), mean follow up of 774 +- 359.5 days). Three latent classes were identified for each task, with the PsychoM task identifying a group of pwRRMS with a mean predicted trajectory of slowing reaction times. In validation, the PsychoM task was the most consistent with the smallest RMSE for each of the 3 classes (68 milliseconds (ms), 95%CI 59-77ms; 61ms, 95% CI 50-72ms and 16ms, 95% CI 14-18ms) followed by the VisAtt task (RMSE = 114ms, 95ms and 29ms) and WorkingM task (RMSE = 137ms, 138ms and 46ms). Reduced datasets of 3, 4 and 5 tests per participant in the PsychoM task were able to classify participants into the trajectories identified in the full dataset model, with 83%, 86% and 90% accuracy respectively.

Conclusions

Latent class modelling of longitudinal reaction times collected with MSReactor was able to detect discrete trajectories of cognitive performance. The PsychoM task latent class model identified a group of RRMS with a mean predicted slowing of reaction times and was the most consistent model in cross validation. Performing the modelling on just 3, 4 or 5 tests per participant was highly accurate in defining latent trajectories, giving the battery clinical utility where multiple years of follow up may not be realistic.

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