Author Of 2 Presentations
P0151 - Serum contactin-1 levels as a biomarker of long-term disease progression in natalizumab-treated multiple sclerosis. (ID 1674)
Abstract
Background
Contactin-1 (CNTN1) is a protein that is expressed in paranodal axonal domains and involved in myelin formation in the central nervous system (CNS) by way of axo-glia interaction, which is affected in multiple sclerosis (MS). Studying patients under natalizumab treatment provides a model to investigate correlations of novel biomarkers with non-inflammation induced disease progression in MS.
Objectives
To investigate longitudinal serum CNTN1 in relation to clinical and radiological disease activity and progression independent of inflammatory disease activity in relapsing-remitting MS (RRMS).
Methods
Eighty-nine natalizumab-treated RRMS patients with minimum follow-up of 3 years were selected from an ongoing observational cohort study. Serum CNTN1 was analyzed at baseline before natalizumab initiation, and at 3, 12, 24 months and last follow-up. Clinical and radiological characteristics and CNTN1 levels were compared between patients with either progressive, stable or improved disability according to ‘EDSS plus’ criteria: Expanded Disability Status Scale (EDSS), 9-hole peg test (9HPT) and timed 25-foot walk test (T25W) combined. A significant change in at least one assessment was defined as progression (increase) or improvement (decrease), and no significant changes in any assessment as stability.
Results
Forty-three subjects (48%) showed disability progression on EDSS plus between reference and last follow-up visit, 34 (38%) remained stable and 12 (13%) improved (median [interquartile range (IQR)] follow-up 5.2 [4.3-6.7] years). No statistically significant differences were found in the proportion of patients with clinical and radiological evidence of disease activity 1 year prior to baseline or during follow-up. Baseline serum CNTN1 (median [IQR], pg/mL) was significantly lower in the group with progressive disability (920 [798-1283]) compared to patients with either stable (1169 [861-1367] p=0.043) or improved disability (1133 [1046-1378], p=0.031). A 100 pg/ml increase in baseline CNTN1 was consistent with an odds ratio [95% confidence interval] of 0.809 [0.684-0.958] (p=0.014) for disability progression. Longitudinal serum CNTN1 levels remained consistently lower in the group with progressive disability compared to the non-progressive group (stable and improved group together).
Conclusions
Long-term disability progression in MS patients treated with natalizumab was associated with lower serum CNTN1 concentrations compared to patients with either stable or improved disability.
P0570 - Dynamic functional connectivity as a neural correlate of fatigue in multiple sclerosis (ID 1455)
Abstract
Background
More than 80% of multiple sclerosis (MS) patients experience symptoms of fatigue. MS-related fatigue can only partly be explained by structural (lesions and atrophy) and functional (brain activation and conventional static functional connectivity) brain changes.
Objectives
To investigate the relationship of dynamic functional connectivity (dFC) with present and future fatigue in MS patients and compare this with commonly used clinical and MRI parameters.
Methods
In 35 relapsing-remitting MS patients (age: 42.8, female/male: 20/15, disease duration: 11 years) and 19 healthy controls (HC) (age: 41.4, female/male: 11/8), fatigue was measured using the CIS-20r questionnaire at baseline and at a 6-month follow-up. Furthermore, disability (EDSS) was assessed for patients. All subjects underwent structural MRI and resting-state functional MRI at baseline. We calculated global static functional connectivity (sFC) and assessed dynamic connectivity using a tapered sliding-window approach by calculating the summed difference (diff) and coefficient of variation (cov). Moreover, we calculated connectivity between basal ganglia and cortical regions previously associated with fatigue in MS (medial prefrontal cortex, posterior cingulate cortex, and precuneus). We performed hierarchical regression analyses with forward selection to identify the most important predictors of fatigue at baseline and follow-up.
Results
Patients were more fatigued than HCs at baseline (MS: 74.36 ± 29.33; HC: 46.72 ± 17.06; p=0.001) and follow-up (MS: 69.91 ± 27.01; HC: 45.11 ± 19.84; p=0.002). No difference in sFC was found between patients and controls. Patients had higher baseline global dFC than controls (p<0.05) but no difference in basal ganglia-cortical dFC. Basal ganglia-cortical dFC-cov added 12.5% extra explained variance (standardized β=-0.353, p=0.032) on top of EDSS (standardized β=0.380, p=0.022) to a regression model for baseline fatigue in patients (adjusted R2=0.211, p=0.011). Post-hoc analysis revealed lower basal ganglia-cortical dFC-cov in patients with severe fatigue at baseline (0.89 ± 0.06) compared to non-fatigued patients (0.93 ± 0.05; p=0.036).
Conclusions
Less dynamic connectivity between the basal ganglia and the cortex is associated with greater fatigue in MS patients, independent of disability status. These findings may reflect less efficient network reconfigurations of those connections as a potential additional neural correlate of fatigue in MS.