Background

Serum neurofilament light chain (sNfL) reflects neuro-axonal damage and may qualify as a biomarker of suboptimal response to disease modifying therapy (DMT).

Objectives

To investigate the predictive value of sNfL in clinically isolated syndrome (CIS) and relapsing-remitting (RR) MS patients with established DMT for future MS disease activity in the Swiss MS Cohort Study.

Methods

All patients were on DMT for at least 3 months. sNfL was measured 6 or 12-monthly with the NF-light^®assay. The association between sNfL and age was modeled using a generalized additive model for location scale and shape. Z-scores (sNfLz) were derived thereof, reflecting the deviation of a patient sNfL value from the mean value of same age healthy controls (n=8865 samples). We used univariable mixed logistic regression models to investigate the association between sNfLz and the occurrence of clinical events (relapses, EDSS worsening [≥1.5 steps if EDSS 0; ≥1.0 if 1.0-5.5 or ≥0.5 if >5.5] in the following year in all patients, and in those fulfilling NEDA-3 criteria (no relapses, EDSS worsening, contrast enhancing or new/enlarging T2 lesions in brain MRI, based on previous year). We combined sNfLz with clinical and MRI measures of MS disease activity in the previous year (EDA-3) in a multivariable mixed logistic regression model for predicting clinical events in the following year.

Results

sNfL was measured in 1062 patients with 5192 longitudinal samples (median age 39.7 yrs; EDSS 2.0; 4.1% CIS, 95.9% RRMS; median follow-up 5 yrs). sNfLz predicted clinical events in the following year (OR 1.21 [95%CI 1.11-1.36], p<0.001, n=4624). This effect increased in magnitude with increasing sNfLz (sNfLz >1: OR 1.41 [95%CI 1.15-1.73], p=0.001; >1.5: OR 1.80 [95%CI 1.43-2.28], p<0.001; >2: OR 2.33 [95%CI 1.74-3.14], p<0.001). Similar results were found for the prediction of future new/enlarging T2 lesions and brain volume loss. In the multivariable model, new/enlarging T2 lesions (OR 1.88 [95%CI 1.13-3.12], p=0.016) and sNfLz>1.5 (OR 2.18 [95%CI 1.21-3.90], p=0.009) predicted future clinical events (n=853), while previous EDSS worsening, previous relapses and current contrast enhancement did not. In NEDA-3 patients, change of sNfLz (per standard deviation) was associated with a 37% increased risk of clinical events in the subsequent year (OR 1.37 [95%CI 1.04-1.78], p=0.025, n=587).

Conclusions

Our data support the value of sNfL levels, beyond the NEDA3 concept, for treatment monitoring in MS clinical practice.

Background

Neuromyelitis optica spectrum disorders (NMOSD) encompasses a group of rare inflammatory diseases which primarily target the optic nerves, spinal cord, and brain. Typically, magnetic resonance imaging (MRI) data from single-center studies comprise 20-50 patients, limiting statistical power for outcomes research. Using retrospective data from the PArallel MRI in NmOsd (PAMRINO) study, a novel prospective NMOSD image repository (NMOsDIR) representing multiple international sites was coordinated by Charité-Universitätsmedizin Berlin and the Medical Image Analysis Center (Basel).

Objectives

The PAMRINO study aimed to investigate and analyze retrospective MRIs collected from NMOSD-specialized centers, potentially for the evaluation of disease-related brain and spinal cord changes. NMOsDIR serves as an international imaging research resource (comprising standardized retinal optical coherence tomography and MRI scans) and clinical data hub for prospective studies in NMOSD. Linking imaging and clinical data, as well as enabling analysis pipelines for each modality, will facilitate multi-centered studies using sufficient data and statistical power to advance outcomes research in this rare disease.

Methods

For clinical data collection in PAMRINO, a Research Electronic Data Capture (REDCap) platform was used, where participating centers entered data relevant for NMOSD patient monitoring. An image database (XNAT) was established for image uploads. This large collection of MRI data is currently being analyzed in a joint international effort of NMOSD clinical neuroradiologists and scientists.

Results

Brain, spinal cord, and optic nerve MRI scans with associated clinical data were collected from 514 NMOSD patients and 56 healthy controls from 17 international centers. Roughly 20,000 individual MRI scans from patients and healthy controls were collected. Of these, 78% had T1-weighted cerebral MRIs (55% with 3D scans), 80% had T2-weighted cerebral MRIs (54% with 3D scans), 86% had T2-weighted spinal cord MRIs (55% with 3D scans), and 35% had optic nerve MRIs.

Conclusions

We successfully established PAMRINO, an international collaborative retrospective MRI and clinical data repository. The knowledge gained during this process provided important new insights, where the initial analysis of the dataset has underscored the large degree of heterogeneity in image and clinical data collection in NMOSD-specialized centers. Thus, calling for more standardized methods of data acquisition and imaging analysis, as not to limit research opportunities. The new longitudinal, prospective NMOsDIR will help us to answer many pressing - yet open - questions regarding patients seropositive for aquaporin-4-IgG+, myelin oligodendrocyte glycoprotein-IgG+ and other autoimmune-related diseases. In turn, such a strategy will strengthen future capabilities in research, diagnosis, monitoring and improving NMOSD patient care.

Background

Ponesimod (PON), an orally active, highly selective and reversible modulator of sphingosine-1-phosphate receptor 1, reduces circulating lymphocytes by sequestration in lymphoid organs. In the phase-3 OPTIMUM study (NCT02425644), PON showed superior efficacy vs teriflunomide (TER) in patients with relapsing multiple sclerosis (RMS).

Objectives

To evaluate prespecified MRI-based endpoints and no evidence of disease activity (NEDA) status in patients with RMS.

Methods

Patients (18-55 years) with RMS (expanded disability status scale scores: 0-5.5) were randomized (1:1) to receive PON 20 mg or TER 14 mg for 108 weeks. MRI endpoints included: percentage change from baseline to week 108 in brain volume (SIENA, Structural Image Evaluation, using Normalization of Atrophy), mean number of new gadolinium-enhancing (Gd+) T1 lesions and volume/count of new/enlarging T2-weighted (T2) lesions. NEDA-3 (absence of confirmed relapse, 12-week confirmed disability accumulation, Gd+T1 and new/enlarging T2 lesions on annual MRIs) and NEDA-4 status (NEDA-3 and no average annual brain volume decrease ≥0.4%) were evaluated from baseline to week 108.

Results

985/1133 (86.9%) randomized patients completed the study. MRI findings for PON vs TER from baseline to week 108, respectively, were: least square (LS) mean percent change from baseline in brain volume: −0.91% vs −1.25% (difference: 0.34%, 95% CLs: 0.17;0.50, p<0.0001); LS mean difference (PON−TER) in change from baseline in total T2 lesion load: −399.2 mm³ (95% CLs: −651.5;−146.8, p=0.002); mean number of new/enlarging T2 lesions per year: 1.40 vs 3.16 (rate ratio [RR]: 0.44, 95% CLs: 0.36;0.54, p<0.0001); PON vs TER odds ratio (OR [95% CL]) for absence of new/enlarging T2 lesions: 1.71 (1.30;2.25, p=0.0001); mean number of new Gd+T1 lesions per scan: 0.18 vs 0.43 (RR: 0.42, 95% CLs: 0.31;0.56, p<0.0001); PON vs TER (OR [95% CL]) for absence of new Gd+T1 lesions: 2.18 (1.61;2.95, p<0.0001). At week 108, 28.2% (159/564) PON vs 18.3% (102/558) TER patients (OR: 1.70, 95% CLs: 1.27;2.28, p=0.0004) achieved NEDA-3; 15.0% (79/526) PON vs 8.5% (45/532) TER patients (OR: 1.85, 95% CLs: 1.24;2.76, p=0.0026) achieved NEDA-4. The most common reason for not achieving NEDA-3 or NEDA-4 status was presence of new/enlarging T2 lesions.

Conclusions

PON showed benefit vs TER for all MRI outcomes including brain volume loss and a significantly higher proportion of patients achieved NEDA-3 and NEDA-4 status, supporting the effects observed on clinical endpoints.

Background

Additional biomarkers reflecting disease activity and predicting severity of multiple sclerosis (MS) are urgently needed.

Objectives

To explore whether intrathecal immunoglobulin (Ig) M synthesis is associated with time from disease onset to first relapse, MS Severity Score (MSSS) and time to first initiation of high efficacy disease modifying treatments (DMT) in patients with relapsing MS in the Swiss Multiple Sclerosis Cohort study.

Methods

487patients were categorized by presence of CSF oligoclonal IgG bands (OCGB) and quantitative intrathecal IgG and IgM production (Intrathecal Fraction, IF). Treatments were classified according to "no therapy", "platform", "oral" and "high efficacy". Multivariable Cox proportional hazard models or a multivariable linear model, adjusted for relevant covariables, were used to assess time from disease onset to described endpoints and associations with the MSSS.

Results

OCGB were present in 89.3%, IgGIF in 66.3%, IgMIF in 26.9% and IgAIF in 11.9% of patients. Patients with IgMIF had a shorter interval from disease onset to first relapse (HR 1.887 [CI 1.181, 3.014], p<0.01) compared to those without OCGB and IgGIF and IgMIF. Quantitatively, patients with IgMIF above versus below the median had a 1.75- fold increased hazard of occurrence of a first relapse (HR 1.746 [CI 1.097, 2.781]; p=0.019). IgMIF positive patients had on average a 1.24 steps higher MSSS compared with those without any intrathecal Ig synthesis (estimate: 1.243 [CI 0.501,1.986], p<0.01), followed by patients with OCGB and quantitative production of IgGIF (estimate: 0.966 [CI 0.283, 1.650], p<0.01) and patients with only OCGB (estimate: 0.716 [CI -0.030, 1.461], p=0.060). Accordingly, patients with IgMIF production had a shorter interval to initiation of high efficacy DMT (HR 2.788 [CI 1.306, 5.951], p<0.01). Quantitatively, above versus below median IgMIF was associated with a 2.36-fold risk of escalation to a high efficacy DMT (HR 2.361 [CI 1.304, 4.277]; p<0.01).

Conclusions

In relapsing MS, presence of intrathecally produced IgM is associated with higher disease activity, more severe disease course and earlier use of high efficacy treatments. Intrathecally produced IgM may qualify as useful prognostic biomarker for therapeutic decision making in early stage of disease.

Background

Serum neurofilament light chain (sNfL) levels reflect neuroaxonal damage and relate to disease activity in MS. sNfL may qualify as well as a biomarker of suboptimal treatment response to disease modifying therapies (DMT). Establishment of age-dependent reference ranges in healthy controls is a prerequisite for developing this biomarker for clinical use.

Objectives

To compare on-treatment sNfL levels with values from a healthy control cohort and to investigate the effect of DMTs on sNfL levels in patients from the Swiss MS Cohort Study.

Methods

sNfL was measured (at baseline and every 6- or 12 months) with the NF-light® assay. Age-dependent sNfL z-scores (sNfLz) were modeled in healthy controls using a generalized additive model for location scale and shape to reflect the deviation of a patient sNfL value from the mean value of same age healthy controls. Linear mixed models were used to investigate the associations between clinical characteristics, DMT and longitudinal sNfLz. Interaction terms and splines were used to model sNfLz and for comparison log(NfL), and their dynamics under treatment.

Results

sNfL was measured in 1368 patients with 7550 longitudinal samples (baseline: median age: 41.9 yrs; 5.4% CIS, 83.2% RRMS, 5.6% SPMS, 5.8% PPMS; median EDSS: 2.0; median follow-up: 4.6 yrs) and 4133 healthy controls with 8865 samples (median age: 44.8 yrs). In the multivariable model, sNfLz increased with EDSS (0.131/step, [95% CI 0.101;0.161]), recent (<120 days) relapse (0.739 [0.643;0.835]) decreased with age (-0.014/year [-0.02;-0.009]), and time on DMT (-0.040/year [-0.054;-0.027]); sNfLz were lower when sampled while on more effective DMT (oral versus platform injectables: -0.229 [-0.344;-0.144]; monoclonal antibodies (mAB) versus platform injectables: -0.349 [-0.475;-0.224]), (p<0.001 for all associations). sNfLz were inversely associated with the hierarchy in efficacy of mAB over orals and orals over platform therapies with regard to slope and extent of decrease (interaction between time under DMT and DMT class: p<0.001). sNfLz, but not log(NfL) showed normalization of sNfL levels by mAB to healthy control levels.

Conclusions

The dynamic change of sNfLz on DMT reflects closely their relative clinical efficacy and is more meaningful than log(sNfL) by excluding age as a confounding factor. Use of sNfLz based on a large normative database as an age-independent sNfL measure improves the accuracy of the sNfL signal and hence their clinical utility.

Background

Teriflunomide is a once-daily oral immunomodulator approved for treating relapsing multiple sclerosis (RMS) and relapsing-remitting MS, depending on the local label. Efficacy and safety of teriflunomide were established in the phase 2 (NCT01487096) and phase 3 trials of patients with RMS (TEMSO [NCT00134563], TOWER [NCT00751881], TENERE [NCT00883337]) and clinically isolated syndrome (TOPIC [NCT00622700]). In post hoc analysis of TEMSO patients stratified by age, structural image evaluation using normalization of atrophy (SIENA) revealed teriflunomide 14 mg significantly reduced the percentage of brain volume change in patients aged >25 to ≤35 years (48%; P=0.0217) and >45 to ≤55 years (35%; P=0.0092) versus placebo over 2 years.

Objectives

To analyze the effect of teriflunomide treatment on MRI lesion activity in TEMSO study patients with RMS stratified by age.

Methods

In TEMSO, patients were randomized 1:1:1 to receive either placebo or teriflunomide 7 mg or 14 mg for ≤108 weeks (Year 2). Through Year 2, MRI lesion activity (unique combined active lesions [UCAL], contrast-enhancing T1 weighted lesions [CEL], and T2 weighted [T2w] lesions) and safety were assessed in the SIENA analysis subgroup; patients were stratified by age at baseline: ≥18 to ≤25 years (n=97 [10%]); >25 to ≤35 years (n=283 [29%]); >35 to ≤45 years (n=388 [40%]); and >45 to ≤55 years (n=201 [21%]). P values between treatment groups were determined for MRI lesions using a Poisson model.

Results

Of 1086 patients in the TEMSO core study, 969 (89%) had scans appropriate for SIENA analysis. Compared with placebo, teriflunomide 14 mg significantly reduced the number of UCAL (0.31–1.44 vs 0.92–6.11 lesions; P≤0.0013) and CEL (0.10–0.46 vs 0.54–3.42 lesions; P≤0.0001) per scan across all age groups. In all age groups except the >45 to ≤55 years group, teriflunomide 14 mg significantly reduced the number of T2w lesions (0.50–0.93 vs 1.07–2.80 lesions; P≤0.001) per scan versus placebo. Similar effects on MRI lesion activity were seen with teriflunomide 7 mg versus placebo. Incidence of adverse events (AEs) generally increased with age, with no deaths reported through Year 2.

Conclusions

Over 2 years in TEMSO RMS patients, teriflunomide reduced the number of new MRI lesions versus placebo across age groups. Significant treatment effects were seen with teriflunomide 14 mg across all age groups for UCAL and CEL. Age-related increases in AEs were observed through Year 2.

STUDY SUPPORT: Sanofi.

Background

Patients with relapsing-remitting multiple sclerosis (RRMS) often experience disease activity despite receiving a disease-modifying therapy (DMT). The Phase IIIb CASTING study (NCT02861014) of ocrelizumab evaluated the efficacy/safety in patients with RRMS who had a prior suboptimal response to one or two DMTs (primary endpoint: 2-year no evidence of disease activity [NEDA] rate).

Objectives

To evaluate CASTING 2-year NEDA outcomes by inclusion criteria, baseline characteristics and prior DMT.

Methods

Patients (Expanded Disability Status Scale [EDSS] score ≤4.0; discontinued prior DMT of ≥6 months’ duration due to suboptimal disease control) received intravenous ocrelizumab 600 mg every 24 weeks for 96 weeks. The primary endpoint of NEDA (with prespecified MRI re-baselining at Week 8) was defined as absence of: protocol-defined relapses, 24-week confirmed disability progression, T1‑weighted contrast-enhancing and new/enlarging T2-weighted lesions over 2 years.

Results

A total of 680 patients were evaluated (female, 64%; mean [SD] baseline EDSS score, 2.1 [1.1]; pretreated with one or two DMTs, including orals and injectables, n=411 [60.4%]/n=269 [39.6%]; enrolled due to activity of: MRI only, n=167 [24.6%]; relapse only, n=238 [35.0%]; MRI and relapse, n=275 [40.4%]). After 2 years, 74.8% (n/N=492/658) of patients had NEDA (with MRI re-baselined at Week 8). The NEDA rate was highest among patients enrolled due to MRI activity alone (80.6%) versus enrollment for relapse (75.1%) or relapse with MRI (70.5%). NEDA rates across disease-related subgroups were highest in the subgroups of baseline EDSS score <2.5 (77.2%), ≤1 relapse prior to enrollment (78.2%) and the event leading to enrollment occurring ≥6 months prior to study entry (75.8%) versus the counterpart subgroups of EDSS score ≥2.5 (70.8%), >1 relapse prior to enrollment (66.3%) and the event leading to enrollment occurring <6 months prior to entry (71.0%). The NEDA rate did not vary by baseline age (≤40 years, 74.7%; >40 years, 75.0%). NEDA rates were higher in patients receiving one prior DMT (77.6%) versus two prior DMTs (70.3%) and remained generally high when stratified by the last prior DMT received before enrollment: interferons, 81.1%; glatiramer acetate, 73.9%; dimethyl fumarate, 73.8%; teriflunomide 69.8%; fingolimod, 68.9%.

Conclusions

The NEDA rate was high overall and across a wide range of disease-related and demographic subgroups, regardless of prior treatment background.

Background

Early treatment of multiple sclerosis (MS) has been shown to provide significant long-term benefits in terms of Expanded Disability Status Scale (EDSS) score versus delayed treatment (patients switching from placebo to active treatment). ENSEMBLE (NCT03085810) is a Phase IIIb study evaluating the effectiveness and safety of ocrelizumab (OCR) in patients with early-stage relapsing-remitting multiple sclerosis (RRMS). Assessments of effectiveness in ENSEMBLE include composite endpoint measures, e.g. the proportion of patients with no evidence of disease activity (NEDA).

Objectives

To report ENSEMBLE 1-year interim NEDA rates.

Methods

Treatment-naive patients with a diagnosis of early-stage RRMS (age, 18–55 years inclusive; EDSS score ≤3.5) per 2010 revised McDonald criteria and a disease duration from the first documented clinical attack consistent with MS disease of ≤3 years and ≥1 clinically reported relapse or ≥1 sign of MRI activity within 12 months of enrollment were included. Patients received OCR 600 mg every 24 weeks (first dose 2×300 mg separated by 14 days) throughout the 192-week (4-year) treatment period (max 8 doses). Clinical assessments will be conducted every 24 weeks. NEDA is defined as absence of: protocol-defined relapses (PDRs), 24-week confirmed disability progression (24W-CDP), T1-weighted contrast-enhancing (CEL) and new/enlarging T2-weighted (T2w) lesions. The effects of OCR are not immediate. MRI measures were re-baselined at Week 8 (prespecified) so that the calculation of NEDA would reflect a more accurate treatment effect.

Results

A total of 678 patients (female, 64.6%) were enrolled (74.6% of patients based on the presence of reasons of both MS relapse and MRI activity) and analyzed. Baseline demographics and disease characteristics reflected a population with early-stage disease (mean [SD]: age, 32.4 [9.1] years; baseline EDSS, 1.71 [0.95]; time since RRMS diagnosis, 0.36 [0.40] years; time since MS symptom onset, 1.10 [0.84] years). At Week 48 most patients (84.8% [n/N=545/643]) reached NEDA. Most patients were free of PDR (98.1%), 24W-CDP (94.1%), CEL (94.2%; re-baselined) and new/enlarging T2w (95.2%; re-baselined) lesions. NEDA calculated without MRI re-baselining was achieved by 62.1% of patients (n/N=404/651). Safety results were consistent with prior studies.

Conclusions

In ENSEMBLE, the Year 1 NEDA rate with MRI re-baselining was high (84.8%) in patients with early-stage disease. No new safety signals were observed.

Background

Although diffusion tensor imaging (DTI) has been widely used to investigate the microstructure of white matter (WM) in patients with multiple sclerosis (MS), it has several limitations; thus different approaches to model diffusion magnetic resonance imaging (dMRI) data are needed.

Objectives

To investigate alterations in the normal appearing WM (NAWM) of cognitively preserved relapsing remitting MS (RRMS) patients using different modelling of dMRI data.

Methods

We included 39 patients (23 females; mean age: 34±6.7 years; median EDSS: 2, range 0-4; mean disease duration: 7±4.6 years) and 39 age- and gender-matched healthy controls (HC). All subjects underwent cognitive (corsi block, n-back, PASAT) and clinical assessment (EDSS) as well as MRI using a 3 Tesla scanner (Siemens Prisma). We assessed 14 diffusion measures applying DTI, freewater volume fraction (FW) corrected tissue DTI (tDTI) and High Angular Resolution Diffusion Imaging (HARDI). Streamline-based particle filtering tractography was used to extract 33 major WM bundles with a multi-atlas/multi-parameter version of RecoBundle. For every bundle, the average of each diffusion measure was computed for the NAWM section. Groups were compared using t-tests and corrected for multiplicity (FDR, q=0.05).

Results

Patients and controls did not differ in cognitive performance. For each measure, the number of bundles showing a group difference and the effect size are reported: DTI (AD: 3 bundles, effect size r:0.3-0.47; RD: 16, r:0.29-0.44; MD: 16, r:0.29-0.48; FA: 11, r:-0.28- -0.5, MODE: 1,r:-0.29), tDTI (FW: 16, r:0.28-0.56; ADt: 2, r:0.34-0.44; RDt: 15, r:0.28-0.43; MDt: 14, r:0.29-0.41; FAt: 11, r:-0.29- -0.5) and HARDI (apparent fiber density (AFD): 9, r:-0.31- -0.41; generalized fractional anisotropy (GFA): 10, r:-0.29- -0.5; anisotropic power (AP): 10, r:-0.28- -0.51; number of fiber orientations (NuFO): 2, r:0.28-0.29). Differences were most prominent in the right arcuate fasciculus, right inferior fronto-occipital fasciculus, bilateral inferior longitudinal fasciculus, right optic radiation and right superior longitudinal fasciculus.

Conclusions

All approaches used to model dMRI data showed structural alterations of several major WM bundles associated with cognitive functions despite patients’ normal cognitive performance. Hence, diffusion MRI could be used to assess disease progression in early stages of the disease when compensatory mechanisms can still support normal cognitive performance.

Background

The pathogenesis of neurodegeneration in multiple sclerosis (MS) is multifactorial and the determinants of brain atrophy rates are not completely understood.

Objectives

To investigate the association between annualized atrophy rate (AAR) of multiple brain measures (regional cortical thickness (CTh), volumes of basal ganglia, thalamus, white matter, gray matter, brain and brain parenchymal fraction (BPF)) and: (1) annualized rate of new and enlarging white matter lesions (WMLs); (2) annualized rate of resolved WMLs; (3) occurrence of progression independent of relapse activity (PIRA) during follow-up.

Methods

We included 1573 1.5T or 3T brain MRI scans from 378 patients of the Swiss MS Cohort Study (331 relapsing-remitting MS (RRMS), 27 clinically isolated syndrome (CIS), 11 secondary-progressive MS (SPMS), 9 primary-progressive MS (PPMS); 70% female; median age: 41.9 yrs; disease duration: 8.3 yrs; EDSS: 2.0; follow-up time: 4.0 yrs). Longitudinal changes in WMLs were obtained using an automated prototype (LeMan-PV). Brain volumes and CTh AARs were obtained using FreeSurfer longitudinal pipeline (v6.0) after WMLs filling. In patients fulfilling PIRA an EDSS progression had to be confirmed ≥6 months after the index event. Multivariable generalized linear models were used to model the association between AAR (dependent variable) and independent variables (1-3), correcting for age, sex, disease duration and baseline EDSS. p-values were adjusted for Bonferroni multiple comparison correction; for vertex-wise CTh analysis, Monte Carlo Z simulation was performed (cluster threshold p<0.05).

Results

We found positive associations between annualized rate of new and enlarging WMLs and (i) CTh AAR of 8 extensive clusters (bilateral frontal, temporal and occipital regions and right insula, all p<0.01) and (ii) AAR of: caudate bilaterally (p=0.02), white matter volume, brain volume and BPF (p<0.001 for all).

We also found a negative association between annualized rate of resolved WMLs and CTh AAR in 3 cortical clusters (right insula, precentral area and anterior cingulate region, all p<0.05); no associations with AAR of volumes emerged.

57 patients fulfilled PIRA whereas 295 experienced no EDSS progression events: no significant differences in AAR measures were found between these two groups.

Conclusions

In a large cohort of MS patients, with a median follow-up of 4 years, local radiological inflammatory and reparative activity were associated with AAR in multiple brain regions. PIRA did not seem to be related to increased AAR in any of the regions studied.

Background

Clinical and imaging features of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) may overlap with those of aquaporin 4-neuromyelitis optica spectrum disorder (AQP4-NMOSD) and relapsing remitting multiple sclerosis (RRMS). There is an unmet need for MRI biomarkers which reflect biological mechanisms involved in MOGAD and can help in the differential diagnosis.

Objectives

We aim to identify imaging features able to differentiate between non-acute MOG-antibody disease, AQP4-NMOSD and RRMS.

Methods

In this ongoing retrospective, cross-sectional MAGNIMS study, we analyzed data collected from 8 centers. All subjects (n=352) had brain and cervical cord 3T MRI. Quantification of MRI biomarkers included brain white matter lesions (WMLs), cortical lesions (CL), brain parenchymal fraction (BPF), white matter fraction (WMF), cortical and deep grey matter fractions (GMF) and cross-sectional cervical cord area (CSA) at C1-C2. Linear regression models were used to compare MRI measures between groups, corrected for age, sex, and centre. Statistical significance was considered when p was <0.05.

Results

91 patients with MOGAD (50F, mean age: 41yrs [±15]), 85 with AQP4-NMOSD (68F, 49yrs [±14]), 90 with RRMS (56F, 41yrs [±11]) and 87 healthy controls (HCs) (54F, 36yrs [±11.6]) were collected. The most common phenotypes at onset were optic neuritis and transverse myelitis in MOGAD (93%) and AQP4-NMOSD (87%). WMLs were detected in 57% MOGAD, 79% AQP4-NMOSD, all RRMS (100%) patients, and in 15% HCs. The mean lesion load and number of lesions were higher in RRMS than both MOGAD (p=0.007, p<0.001) and AQP4-NMOSD (p=0.001, p<0.001). At least one CL was seen in 8% patients with MOGAD (total n=8), 10% patients with AQP4-NMOSD (n=7), and in 69% patients with RRMS (n=150). All patient groups showed lower BPF than HCs, with lower WMF in MOGAD and RRMS than HCs (all p<0.01). Between groups, deep GMF was lower in RRMS than MOGAD (p<0.001) and AQP4-NMOSD (p=0.001). CSA was reduced in all disease groups when compared to HCs (all p<0.01) and lower in AQP4-NMOSD than RRMS (p=0.01).

Conclusions

This ongoing study indicates that MOGAD and AQP4-NMOSD share similar MRI features, and no specific MRI biomarker can distinguish between them. Patients with AQP4-NMOSD showed greater spinal cord atrophy than RRMS, and RRMS patients had a higher number of cortical lesions, and greater deep GM atrophy than AQP4-NMOSD and MOGAD. The next step is to investigate whether lesion distribution differs between the two antibody-mediated disease.

Background

Neuromyelitis optica spectrum disease (NMOSD) and multiple sclerosis (MS) have a different pathophysiology. Accumulating evidence suggests that the choroid plexus plays a pivotal role in the pathogenesis of MS. However, MRI data comparing the choroid plexus volume between MS and NMOSD are scarce.

Objectives

To compare the choroid plexus volume in MS vs. NMOSD in vivo using high-resolution 3D MRI data. Migraine patients and healthy individuals served as control groups.

Methods

We included 95 MS patients [45% secondary progressive (SP); mean age 51.0±11.5 years; disease duration 20.8±10.4 years, 62% female; median Expanded Disability Status Scale (EDSS) 4.0], 43 NMOSD patients [28/43 anti-aquaporin 4 antibody positive; 11/43 anti-myelin oligodendrocyte glycoprotein antibody positive; 87% female; mean age 50.0±13.8 years; disease duration 6.8±7.3 years, median EDSS 3.0], 38 migraine patients [mean age 39±13 years, 79% female; 15/38 migraine with aura] and 65 healthy individuals [HCs, mean age 41±17 years, 48% female]. The choroid plexus of the lateral ventricles and T2-weighted (T2w) white matter lesions (WMLs) were segmented fully automated on T1-weighted (T1w) magnetization-prepared rapid gradient echo (MPRAGE) images and fluid attenuated inversion recovery sequences (FLAIR, voxel size of both sequences 1x1x1 mm³), respectively, using a supervised deep learning algorithm (multi-dimensional gated recurrent units). Total intracranial volume (TIV) and lateral ventricle volumes were assessed fully automated using Freesurfer. All outputs were reviewed and manually corrected (if necessary) using 3D-Slicer by trained raters who were blinded to the clinical information. Group differences were analyzed using multivariable generalized linear models (GLMs) adjusted for age, gender, TIV and lateral ventricle volume. Cohens’ d was used to calculate the standardized difference between the respective groups. Given p-values are adjusted for multiple comparisons (Bonferroni).

Results

Mean choroid plexus was larger in MS compared to NMOSD (1907±455 vs. 1467±408 µl; p<0.001, d=0.86), HCs (1663±424 µl; p=0.007, d=1.17) and migraine (1527±366 µl; p=0.02, d=0.72). There was no statistical difference in the choroid plexus volume between NMOSD, migraine and HCs. The choroid plexus was marginally larger in RRMS than SPMS (1959±482 vs. 1875±476 µl; p=0.28; d=0.17) and in untreated MS patients compared to MS patients on disease modifying therapy (2111±382 vs. 1876±459 µl; p=0.36). However, these differences did not reach statistical significance after correction for multiple comparisons. There was no association between the choroid plexus volume and total T2w WML volume in MS.

Conclusions

Patients with MS have larger choroid plexus than HCs, migraine and NMOSD patients. Further studies are warranted to investigate the respective roles of the choroid plexus in the pathogenesis of MS and NMOSD.