2014 Joint ACTRIMS-ECTRIMS Meeting (MSBoston 2014): Oral Presentations

2014 Multiple Sclerosis  
It is well established that TH17 lymphocytes are crucial in the pathogenesis of the chronic autoimmune disease multiple sclerosis (MS). However, the importance of IL-17 in MS is still under debate, and other TH17-associated cytokines are likely more crucial in the initiation and maintenance of neuroinflammation. Objectives: In this study, we addressed the function of IL-26 and its role as TH17-associated cytokine in blood brain barrier (BBB) breakdown and neuroinflammation. Methods: To
more » ... that IL-26 is a TH17-associated cytokine, qPCR for IL-26 and established TH17 markers was performed on differentiated TH17 cells. The expression of IL-26 was confirmed by western blot (WB) and immunohistofluorescence (IHF). ELISA was used to determine expression of IL-26 in serum and cerebrospinal fluid (CSF) of MS patients and controls, and to analyze supernatant of human blood brain barrier endothelial cells (BBB-ECs) after IL-26 treatment. Expression of the IL-26R (IL-10Rbeta/ IL-20Ralpha) and tight junction proteins on BBB-ECs was analyzed using WB and IHF. Permeability of BBB-EC monolayers after IL-26 treatment was assessed using dextran and BSA diffusion assays. In vivo permeability after i.p. IL-26 treatment of C57Bl/6 mice was assessed by IHF (Evans Blue, fibrinogen and ICAM-1) and 2-photon microscopy (fluorescent dextran). Results: We demonstrate that IL-26 is specifically produced by human TH17 lymphocytes and that it correlates strongly to other TH17-associated markers. IL-26 is increased in the serum and CSF of untreated MS patients, as compared to controls or to treated MS patients. Human BBB-ECs express a functional IL-26R both in vitro and in situ, since they respond to IL-26 treatment by secreting IL-8 and IP-10. IL-26 treatment of BBB-EC monolayers increases their permeability and decreases expression of the tight junction molecule occludin. In vivo, IL-26 treatment increases Evans Blue extravasation in the CNS. Furthermore, we find a significant perivascular accumulation of fibrinogen 2 to 8 hours after IL-26 injection, an upregulation of ICAM-1 on the surface of BBB-ECs, and perivascular accumulation of immune cells in the CNS. This was confirmed by in vivo two-photon microscopy, showing leakage of fluorescent dextran after injection of IL-26. Conclusions: Taken together, these data strongly suggest that IL-26 i) is a TH17-associated cytokine, ii) is correlated to MS disease activity and iii) increases BBB permeability and transmigration of TH lymphocytes, and possibly other immune cells. YI1.2 DICAM: a novel molecular effector in neuroinflammation CD4 + T lymphocytes in active demyelinating lesions and in some early pre-active lesions. DICAM-expressing cells were found to co-express IL-17. Finally, qPCR analysis of DICAM expression in CD4 + and CD8 + T lymphocytes collected from the blood of MS patients revealed a significant up-regulation of DICAM in untreated RRMS patients, as compared to healthy donors. Conclusions: These data are in strong support of the role that DICAM could play in the transmigration and the recruitment of TH17 lymphocytes across CNS vascular barriers. YI1.3 Clinical disease burden predicts myelin water fraction in multiple sclerosis Background: An imaging marker that can accurately and specifically ascertain myelin content is essential to investigate myelin variability within lesions and normal appearing white matter (NAWM) and to explore predictors of these differences among MS patients. T2 relaxometry is an MRI technique in which the contribution of water associated with myelin can be represented as myelin water fraction (MWF). Objectives: In this study we applied our fast whole brain T2 acquisition (T2prep SPIRAL) to a large cohort of patients with multiple sclerosis (MS) and investigated the distribution and predictors of MWF. Methods: One hundred and forty one MS patients and 10 agematched healthy controls (HC's) had T2prep 3D SPIRAL sequence acquired. The SPIRAL data was analyzed with a spatially constrained multi-Gaussian post-processing algorithm to create MWF maps. For each patient, the distribution of MWF values was modeled using a mixture of two gamma distributions. Multi-variate linear regression models were utilized to predict white matter MWF distribution. Results: Among all patients, the mean NAWM MWF (0.12 ± 0.05) was significantly higher compared to lesion MWF (0.05 ± 0.05), p ≈ 0 in a voxel-based analysis. Individual whole brain white matter MWF in patients was modeled and followed a bimodel modeled distribution (94%) as compared to HC's (10%). The strongest predictive model (adjusted R 2 = 0.89, p< 2.2 x 10 -16 ) revealed a significant association with increasing EDSS (p = 3.84 x 10 -5 ) and longer disease duration (p = 0.0122) with lower MWF values in lower curve of the bi-model distribution. Conclusions: Through our technique, we efficiently assessed whole brain white matter MWF in a large cohort of MS patients. The distribution of white matter MWF follows a bi-model distribution, likely reflecting lesion and NAWM. Increasing clinical burden of disease predicts lower MWF values which suggests a progressive loss of myelin with accumulating disease. Our results represent one of the first quantitative studies characterizing the distribution of whole brain white matter MWF distribution, and relating these measures to clinical disease burden. Importantly, we have identified factors that may potentially contribute to lower WM myelin values; these variables and potentially others will need to be considered when designing remyelination treatment trials. YI1.4 In vivo 7T MRI characterization of leptomeningeal enhancement in multiple sclerosis Background: Leptomeningeal inflammation has been described and pathologically documented in multiple sclerosis (MS). Typically, clusters of inflammatory cells in the cerebral leptomeninges are closely associated with meningeal vessels. Within the subarachnoid space, focal gadolinium (gad)-enhancement on T2-FLAIR 3T MRI has recently been recognized to be a potential in vivo marker of leptomeningeal inflammation in MS. However, the structural correlates of this enhancement have remained elusive, probably due to the small dimensions of the inflammatory clusters. Objectives: Structural in vivo characterization of leptomeningeal enhancement (LME) in multiple sclerosis (MS) via 7 tesla (7T) MRI. Methods: On a 7T MRI system, we studied 7 cases with known LME based on prior 3T scans. We acquired whole-brain 3D T2-FLAIR and T1-weighted magnetization-prepared rapid gradient echo (T1-MPRAGE) scans, as well as high-resolution multislice gradient-echo scans providing T2* contrast (voxel size=0.2x0.2x1 mm) and acquired in two planes. Sequences were repeated before and after injection of 0.1 mmol/kg of gadolinium contrast. Results: In all cases, LME was stable since the 3T scan and was clearly detectable on post-gad T2-FLAIR. In all cases, LME was seen to be closely related to one or more meningeal vessels, which were clearly depicted on the T2* sequence. Despite the high spatial-resolution scans, no structural finding was found. However, after gad injection, focal bright signal strictly adjacent to a vessel was seen on both T2-FLAIR and T2*. This finding is compatible with leakage of gad from this vessel, with subsequent local flow within the CSF near the vessel. Repetition of the T2-FLAIR scan over the first hour following gad injection demonstrated that the shape and size of the enhancing focus remained constrained. Conclusions: No soft-tissue correlates of LME in MS are seen even on high-resolution 7T MRI scans. However, images acquired post gad suggest that LME detected on T2-FLAIR MRI is probably due to focal opening of the blood-CSF barrier. In visualized foci, spread of gad is limited in space, perhaps by an inflammatory scar. Our findings remain consistent with the pathological description of organized meningeal inflammation described in MS. Background: In Multiple Sclerosis, diffuse degenerative processes in the deep grey matter have been associated with clinical disabilities. Objectives: Our aim was to analyze DGM pathology in MS patients with a focus on the incidence and topographical distribution of lesions, their relationship to inflammation, and the underlying mechanisms of demyelination and neurodegeneration. Methods: We performed a systematic study on a total sample of 75 MS autopsy patients and twelve controls. In addition, detailed analyses of inflammation, acute axonal injury, iron deposition, and oxidative stress were performed on a subsample of MS and control patients. Results: MS deep grey matter was affected by two different processes: the formation of focal demyelinating lesions and diffuse neurodegeneration. Deep grey matter demyelination was most prominent in the caudate nucleus and hypothalamus and could already be seen in early MS stages. Lesions developed on the background of inflammation. Deep grey matter inflammation was intermediate between low inflammatory cortical lesions and active white matter lesions. Demyelination and neurodegeneration were associated with oxidative injury. Iron was stored primarily within oligodendrocytes and myelin fibres and released upon demyelination. In addition to focal demyelinated plaques, the MS deep grey matter also showed diffuse and global neurodegeneration. This was reflected by a global reduction of neuronal density, the presence of acutely injured axons, and the accumulation of oxidised phospholipids and deoxyribonucleic acid in neurons, oligodendrocytes, and axons. Neurodegeneration was associated with T-cell infiltration, expression of inducible nitric oxide synthase in microglia, and profound accumulation of iron. Conclusions: In conclusion, we show that the DGM is profoundly involved in the disease progression of MS patients and appears to contribute significantly to the global accumulation of disability in MS patients. In addition to focal demyelination, a diffuse neurodegenerative process occurs in the DGM and is associated with clinical disability. This process may be related to increased oxidative injury and anterograde or retrograde degeneration in a brain area with exceptionally high iron content. YI1.6 Regional thalamic damage and cognitive impairment in patients with multiple sclerosis: a multicenter study A Background: Cognitive impairment affects a large proportion of MS patients and has been related to atrophy and diffusivity abnormalities of the thalamus. Objectives: In this multicenter study, we explored the contribution of regional thalamic structural connectivity abnormalities to cognitive impairment in MS patients. Methods: Brain dual-echo, 3D T1-weighted, and diffusion tensor (DT) MRI sequences were collected from 52 relapsing-remitting MS patients and 57 healthy controls (HC) from six European centers. RAO's neuropsychological battery and Wisconsin Card Sorting Test were assessed. Patients with ⩾2 abnormal neuropsychological tests were considered cognitively impaired (CI). Thalamic subdivision in connectivity defined regions (CDRs) according to cortical projections was performed using Diffusion Tractography-Based Parcellation. Selected target regions were: frontal (F), motor (M), post-central (PC), posterior parietal (PP), temporal (T) and occipital (O) regions. A probabilistic atlas of CDRs was created from HC images and applied to all subjects to derive average values of fractional anisotropy (FA) and mean diffusivity (MD). Between-group differences of global and CDRs thalamic FA/MD values, adjusted for centre, were investigated. Correlations between FA/MD values with global and specific cognitive Z scores were also assessed. Results: Twenty-two (43%) MS patients were CI. Compared to HCs, MS patients had: 1) reduced thalamic volume, bilaterally (p< 0.0001); 2) increased FA of the bilateral (B) global thalamus, B F-CDRs, B M-CDRs and B O-CDRs (0.003< p< 0.04); 3) decreased FA of B T-CDRs (0.0001< p< 0.008); 4) increased MD of B F-CDR, B T-CDR and B O-CDRs (0.0001< p< 0.009). Compared to cognitively preserved patients, CI patients had: 1) reduced B thalamic volumes (p< 0.0001); 2) increased FA of B global thalamus and left F-CDRs, B M-CDRs, B PC-CDRs and B O-CDRs (0.0004< p< 0.05); 3) increased MD of left PC-CDRs, B T-CDRs and B O-CDRs (0.03< p< 0.002). Significant correlations were found between global/specific cognitive Z scores and thalamic volumetric and diffusivity abnormalities. Conclusions: Thalamic involvement in MS is a result of a complex balance between damage to the gray matter (GM) (as detected by increased FA) and white matter (WM) (as detected by reduced FA), with a different distribution in thalamic subregions. The involvement of GM in anterior (F-/M-areas connected) and lateral (P-/O-areas connected) thalamic subregions contributes to cognitive impairment in these patients. YI1.7 Changes in thalamic resting-state functional connectivity induced by a home-based cognitive rehabilitation program in patients with multiple sclerosis Background: Mechanisms underlying cognitive dysfunction and recovery in Multiple sclerosis (MS) are still matter of debate. Recently we demonstrated that thalamic Resting State Network (RSN) is disrupted in MS and that decreased performance in cognitive tests is associated with alteration of thalamo-cortical functional connectivity (FC) (Tona et al. Radiology 2014). Objectives: The aim of the present study is to investigate with resting state (RS) fMRI changes in thalamic connectivity induced by cognitive rehabilitation (CR). For this purpose we used the videogame "Dr. Kawashima Brain Training" (DKBT, Nintendo, Japan), which we have recently shown to be effective in improving attention, processing speed and working memory in patients with MS (De Giglio et al. ECTRIMS 2013) Methods: This was a randomised, wait-list control study. MS patients with failure of at least one between Stroop Test (ST), Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), were submitted to an 8-week home-based CR program playing DKBT. They underwent clinical evaluation and 3Tesla RS-fMRI at baseline (T0) and after CR (T1). FMRI data were analyzed using a seed-based method to identify the thalamic RSN. Between-group analysis of RSN changes at T1 was performed using a two-sample t-test model (unpaired, cluster level p< 0.05, FWE corrected) with the FSL software. Clinical variables were entered into a one-sample model to calculate correlations with FC in the patient group (cluster level p< 0.05, FWE corrected). Results: Twenty-four patients were randomly assigned to either intervention group (n=12) or control group (n=12). We found a significant effect of DKBT on PASAT (F=6.616, p=0.018) and ST (F=5.325, p=0.030). At T1, thalamo-cortical FC showed significant different patterns in the intervention group when compared with controls. Moreover we observed that an improvement in PASAT and ST scores after intervention was related with an increased thalamic FC in specific brain areas. Conclusions: Our study underlines the relevance of thalamic regulation of the brain networks involved in cognitive processes. We suggest that thalamic FC modifications may be considered as a functional substrate for clinical improvement induced by cognitive rehabilitation. Background: Optical coherence tomography (OCT) segmentation derived ganglion cell layer+inner plexiform layer (GCIP) thickness has superior structure-function relationships than conventional peripapillary retinal nerve fiber layer (RFNL) thickness in MS. Although RNFL and GCIP thicknesses correlate with whole brain volume cross-sectionally in MS, it is unclear whether atrophy within retinal and brain compartments are related longitudinally. Baseline inner nuclear layer (INL) thickness might predict inflammatory activity, but how these relate over time is unknown. Objectives: To determine whether atrophy of specific retinal structures is associated with atrophy of specific brain sub-structures and accumulation of lesions in MS. Methods: Cirrus-HD OCT (with automated segmentation) and clinical testing was performed in 107 MS patients bi-annually (mean follow-up: 42-months). MRI brain scans (3T) were performed annually (mean follow-up: 35 months). Brain sub-structure volumes were determined using Lesion-TOADS. Linear regression was used to estimate individual-specific rates of change in retinal and brain-subcompartment measures. These rates were correlated, adjusting for age, sex, disease duration, and optic neuritis history. The impact of measurement error was assessed using the simulation-extrapolation method. Results: GCIP atrophy rate and rates of whole brain (r=0.41, p< 0.001), gray matter (GM; r=0.34, p< 0.001), white matter (WM; r=0.26, p=0.007) and thalamic (r=0.36, p< 0.001) atrophy over time were associated. RNFL atrophy rate was less robustly associated with whole brain (r=0.29, p=0.003), GM (r=0.25, p=0.01), and thalamic atrophy (r=0.33, p< 0.001) rates. GCIP and whole brain atrophy rates were more strongly associated in secondary progressive MS (r=0.74) and primary progressive MS (r=0.44), than relapsing-remitting MS (RRMS; r=0.30). Similar trends according to MS subtype were observed between rates of GCIP, GM and WM atrophy. In RRMS, lesion accumulation rate was associated with rates of GCIP (r=-0.30, p=0.01) and INL (r=-0.28, p=0.02) atrophy. Conclusions: Retinal changes mirror global central nervous system processes in MS. GCIP atrophy reflects whole brain, and in particular GM atrophy, especially in progressive MS. Beyond gleaning information regarding neurodegeneration, tracking OCT provides insight regarding inflammatory activity in RRMS, with perhaps the INL being most useful for this purpose. Our findings validate OCT measures, both for clinical monitoring and as an outcome in clinical trials. YI2.3 A comparison of cognitive performances between multiple sclerosis patients with pediatric-versus adultonset disease
doi:10.1177/1352458514546076 pmid:25205047 pmcid:PMC4518813 fatcat:5giyc6lpwrdhzgjat3fhfcfcmi