Background

We recently showed that 7T MRI leptomeningeal enhancement (LME) is common in relapsing-remitting multiple sclerosis (RRMS) and is related to gray matter (cortical/thalamic) and white matter (WMLs) lesions.

Objectives

To investigate the dynamics of LME longitudinal change and relationship to subsequent lesion accumulation using 7T MRI.

Methods

25 RRMS subjects [age 44.5±11.2 years (mean±SD), 68% women, Expanded Disability Status Scale (EDSS) 2.0±1.5, 92% on disease-modifying therapy-DMT] and 12 healthy controls (HC) underwent brain 3D MP2RAGE and FLAIR 7T MRI with 0.7 mm³ voxels at baseline and ~1 year. Gadolinium-enhanced 3D-FLAIR was evaluated for LME. WMLs, cortical lesions (CLs) and thalamic lesions (TLs) were expert-quantified. Wilcoxon rank-sum, two-sample t-tests and Spearman’s correlations were investigated.

Results

LME was found in 17/25 (68%) RRMS subjects at baseline and 18/25 (72%) at follow-up vs. a single stable focus in 1/12 HC (8.3%). In the RRMS group, 42 LME foci [mean 2.5±1.1 (range 1-5) per LME+ subject] were identified at baseline versus 48 foci [2.7±1.2 (1-5)] at follow-up. LME foci number at follow-up was unchanged in 18 (72%) RRMS subjects, increased in 6 (24%), decreased in 1 (4%). All 6 subjects with increased LME foci were on treatment [glatiramer acetate, interferon-β (2), rituximab, ocrelizumab, fingolimod]. The subject with LME resolution was treated with ocrelizumab. LME+ subjects had an on-study increase in volume of WMLs (baseline 11.0±14.4 vs. follow-up 12.6±16.3 ml, p<0.001), CLs (0.85±1.2 vs. 1.0±1.4 ml, p=0.002) and TLs (0.103±0.093 vs. 0.117±0.099 ml, p=0.005), whereas LME- subjects had an increase only in WML volume (2.7±2.3 vs. 3.3±2.6 ml, p=0.023). Baseline LME foci number correlated with 1-year change in CL (r=0.36, p=0.078) and WML (r=0.50, p=0.010) volumes. Minimal EDSS change over 1 year was noted. We used these data as the basis for a sample size calculation for a hypothetical trial of a putative therapy that would reduce the rate of MRI lesion accrual by 80% over 1 year. For a single-arm study with 1-year run-in on standard therapy and 1 year on new treatment to achieve 80% power, sample sizes of n=46, n=56 and n=79 were calculated for CL volume, TL volume and LME foci number, respectively.

Conclusions

The evolution of cerebral LME may be a dynamic process in the short term in RRMS, providing a monitoring tool, with about one quarter of patients showing new foci at one year. LME may pose a risk for the subsequent development of new lesions in widespread brain regions, implicating meningeal involvement as a marker or mediator of increased disease severity.

Abstract

Background: Multiple sclerosis is characterized by both neuroinflammation and accelerated brain atrophy. These two processes can be quantified by MRI, are at least partially independent, and have different underlying pathological mechanisms. MicroRNA (miRNA) have previously shown strong ties to various neurological disease processes, and have potential as biomarkers in MS.

Objectives: To classify and immunologically characterize persons with MS based on serum miRNA profiles in conjunction with MRI phenotypes, as defined by relative burden of cerebral T2-hyperintense lesion volume (T2LV) and brain parenchymal fraction (BPF).

Methods: Cerebral T2LV and BPF were retrospectively quantified from 1.5T MRI, and used to define the following MRI phenotypes. Type I: low T2LV, low atrophy; type II: high T2LV, low atrophy; type III: low T2LV, high atrophy; type IV: high T2LV, high atrophy, in a large cross-sectional cohort (n = 1,088) and a subset with 5-year longitudinal follow-up (n = 153). Serum miRNAs were assessed on a third MS cohort with 2-year MRI phenotype stability (n = 98). A proportional odds logistic regression model was used to determine significant associations been MRI features and miRNA expression.

Results: One-third of the patients showed dissociation between lesion burden and atrophy severity as defined by MRI phenotypes II or III. At 5-year follow-up, all phenotypes showed increased atrophy (p < 0.001), disproportionally in type II (BPF −2.28%). Only type IV experienced significantly worse neurological disability scores. Types I and II had a 5-year MRI phenotype conversion rate of 33% and 46%, whereas III and IV had >90% stability. Type II switched primarily to IV (91%); type I switched primarily to II (47%) or III (37%). Baseline higher age (p = 0.006) and lower BPF (p < 0.001) predicted 5-year phenotype conversion. MicroRNA analysis revealed sixteen miRNA differentially expressed (p < 0.05, uncorrected) between the four phenotypes. Each phenotype demonstrated a distinct miRNA signature. Biological interpretation of these miRNA suggest a role for blood-brain barrier pathology. miR-22-3p, miR-361-5p, and miR-345-5p were the most valid differentiators.

Conclusions: MRI-defined MS phenotypes show high conversion rates characterized by relentless brain atrophy with or without ongoing inflammation, and results support the partial independence of these two features. Differentially expressed serum microRNA for the MRI phenotypes implicates the blood-brain barrier as an important mechanism determining pathological course. MicroRNA are promising as biomarkers in MS but require significant further verification and methodological standardization.

Background

Thalamic and whole brain atrophy have been extensively studied as biomarkers of neurodegeneration in multiple sclerosis but their mechanism is not clear. [F-18]PBR06-Positron Emission Tomography (PET) is a novel molecular imaging technique to assess microglial activation.

Objectives

To determine the relationship of thalamic and whole brain atrophy with white matter (WM) microglial activation in multiple sclerosis.

Methods

22 individuals (13 MS, including 8 relapsing-remitting and 5 secondary progressive, and 9 healthy control (HC)) subjects underwent 3T MRI and [F-18]PBR06-PET. Individualized z-score maps of WM microglial activation were generated by voxel-by-voxel comparison between each subject's PET SUVR images and a control dataset. Glial activity load on PET in WM (“GALP-WM”) was calculated as the sum of voxel-by-voxel z-scores ≥4 in the WM subjects and its logarithmic transformation (“ln-GALP”) was also obtained. "Z-max" score was calculated as the highest z-score in the WM matter averaged over surrounding 5 voxels. SIENAX and FSL-FIRST pipelines determined normalized brain parenchymal volume (BPV) and thalamic volumes (Th-V) respectively. A p-value <0.05 was considered statistically significant.

Results

Th-V and BPV were lower in MS vs. HC (19.7±2.2 vs. 22.4±1.6 ml, 1376.6±81.3 vs. 1475.1±70.9 ml, both p<0.01). GALP-WM, Z-max and ln-GALP were higher in MS vs. HC (18757.9±13646 vs. 7580.5±12216, 13.2±2.9 vs. 8.3±4.1, and 9.5±0.92 vs. 7.4±1.9, all p<0.05). Th-V and BPV were inversely correlated with WM microglial activation, represented by GALP-WM, Z-max and ln-GALP (r=-0.62, -0.66 and -0.62, all p<0.01 for Th-V and r=-0.68, -0.643 and -0.678, all p<0.01 for BPV) that remained significant after adjustment for age (all p<0.05).

Conclusions

Thalamic and whole brain atrophy are linked with white matter microglial activation in MS, representing a link between neuroinflammation and neurodegeneration across central nervous system compartments. Further investigation of the “GALP” method as a novel, individualized approach for evaluating glial activity in MS is warranted. Prospective longitudinal studies to determine the impact of therapeutically targeting microglial activation on neurodegeneration in MS patients are urgently needed.

Background

Seroepidemiology is an important tool to characterize the epidemiology and immunobiology of SARS-CoV-2. Most people with multiple sclerosis (MS) are treated with immunomodulators or immunosuppressants, so it is crucial to understand the immune response to the novel SARS-CoV-2 in people with MS.

Objectives

To investigate the prevalence and persistence of the SARS-CoV-2 antibody response in MS and how this relates to MS phenotype and treatment.

Methods

227 consecutive people with MS residing in MA and receiving care at Massachusetts General Hospital or Brigham and Women’s Hospital and 143 of their cohabitants were enrolled May 29-July 23, 2020. In addition, 8 people with MS receiving care elsewhere who tested positive for SARS-CoV-2 nasal swab PCR and 7 cohabitants of that group were enrolled to enrich the sample for select analyses. Each participant remotely submitted a dried blood card for in-house MGH SARS-CoV-2 IgG ELISA assay testing. The assay displays 99.7% sensitivity and 100% specificity >14 days from symptom onset. Participants completed a REDCap questionnaire covering demographics, MS history and treatments, comorbidities, and COVID-19 symptoms and exposure. Antibody prevalence in MS participants will be compared to that in their cohabitants using Pearson’s Chi-squared tests.

Results

The majority of MS participants were characterized as relapsing/remitting (76.8%) and were taking disease modifying therapies (72.6%) at the time of collection. SARS-CoV-2 antibodies were detected in 3.5% of people with MS residing in MA and 6.3% of their cohabitants (X²=1.54, p=0.22). For comparison, ~1.5% of the MA population had tested positive by PCR in this date range. Exposure and treatment data will be presented in 13 cases of antibody discordance between the person with MS and his/her cohabitant; the person with MS was antibody-negative in 10 cases and antibody-positive in 3 cases with discordance. In total there were 6 MS participants and no cohabitants who previously tested positive by nasal swab PCR but lacked antibodies at follow-up. Of the COVID-positive participants (by PCR or antibody), 54.5% (6 of 11) of MS and 88.9% (8 of 9) of cohabitants were asymptomatic (p=0.16).

Conclusions

Antibody prevalence was low overall in people with MS residing in MA. Discordance between MS participants and their cohabitants and lack of detectable antibodies in some people with MS with prior nasal swab PCR positivity suggest SARS-CoV-2 antibodies may be less persistent in people with MS.

Background

Multiple Sclerosis (MS) is a complex and heterogeneous disease. Investigating the biological pathways and cell types involved in MS pathophysiology as represented by protein biomarker expression can help inform the development of tools to monitor disease activity, disease progression, identify early evidence of relapse, and monitor treatment response.

Objectives

To develop a blood based multiplex proteomic assay that associates with clinical and radiographic endpoints in patients with MS. These endpoints include the presence of gadolinium-enhanced (Gd+) lesions, Annualized Relapse Rate (ARR) and clinically defined relapse status (active versus stable).

Methods

Serum samples (n=690 in total) from multiple deeply-phenotyped cohorts (ACP, CLIMB and EPIC) were tested in immunoassays for the measurement of 1196 proteins using Proximity Extension Assays (PEA) from Olink^TM and for 215 proteins using xMAP^TM immunoassays from Myriad RBM, Inc. (RBM). Associated radiographic and clinical endpoints at the time of the blood draw were correlated with the protein levels. Twenty-one proteins were selected for inclusion in a custom assay based on their performance in univariate and multivariate statistical models, and replication across independent cohorts. Biological pathway modeling and network analysis were performed to ensure comprehensive representation of MS neurophysiology. Area under the curve (AUC) was selected as the key metric for model performance evaluation.

Results

Multivariate statistical ensembles restricted to the expression levels of the biomarkers selected for the custom assay achieved AUC performance of 0.827 for classification of the presence of Gd+ lesions, 0.802 for classification of clinically defined relapse status, and 0.930 for the classification of patients with Low ARR (≤0.2 relapses) vs High ARR (≥1.0 relapses). A multivariate model utilizing shifts in biomarker expression in longitudinally paired samples achieved the highest observed performance of 0.950 for classification of Gd+ lesion presence. In each case, the multivariate models significantly outperformed (p-value <0.05) the AUC of the highest performing univariate biomarker.

Conclusions

Multivariate models restricted to the 21 selected proteins effectively classified several radiographic and clinical endpoints with stronger performance than any single biomarker. A 21-plex custom assay panel is being developed for further investigation and validation using additional cohorts.

Background

Disability improvement is an important functional measure in progressive MS. The MRI features of disability improvement have not been explored.

Objectives

To assess quantitative brain and spinal cord MRI measures, including volumetric features, that correlate with improvement in the T25FW or 9HPT compared to multiple sclerosis (MS) patients with stable or worsening features.

Methods

A nested cohort from the SysteMS substudy of Comprehensive Longitudinal Investigations in MS at Brigham and Women’s Hospital (CLIMB) Study was selected to match inclusion criteria for patients enrolling in a phase 2 trial of repeat dose intrathecal Mesenchymal Stem Cells-Neurotrophic Factor (MSC-NTF) cells in patients with progressive MS (NCT03799718). 3T MRIs at baseline and at follow-up timepoint (12-24 months later) underwent brain and lesion volumetric analysis by Icometrix, as well as mean upper cervical cord area (MUCCA) which generated 34 measures. These 34 MRI volumetric measures (ml) were compared in patients with improved versus patients with worsening or stable 9-hole peg test (9HPT) or timed-25-foot-walk (T25FW) scores. Results were not corrected for multiple comparisons due to the exploratory nature of this study.

Results

48 patients met inclusion criteria. 17 patients had improved 9HPT score, while 29 had worsened or had stable 9HPT score from baseline to 12-24 months later. Whole brain volume at baseline for these 3 cohorts (Improved 9HPT:1505±51 vs. stable-worse 9HPT:1471±62;p=0.069;t-test) and follow-up (Improved:1501.555±52.039 vs. stable-worse:1461.304±63.562);p=0.03;t-test) differed between the two groups, as did gray matter volume at follow-up (Improved 1505.059 ±50.961 vs. stable-worse 865.57±41.352); p=0.063:t-test). For T25FW, 18 patients had an improved score, while 27 were worsened or stable over the 12-month period. Deep white matter FLAIR/T2 lesion volume at baseline (Improved:0.43±0.507 vs. stable-worse:0.827±0.561;p=0.03;t-test) and follow-up (Improved:0.429±0.503 vs. stable-worse:0.864±0.603;p=0.02) differed between two T25FW groups. MUCCA was not associated with improvement measures.

Conclusions

Improved 9HPT measures over a 12-month period correlated with baseline brain volume, while T25FW improvements correlated with baseline deep white matter T2 lesion volume. These results will inform analysis of clinical outcomes in the ongoing phase 2 clinical trial of MSC-NTF cells in progressive MS.

Background

Although a small number of studies has shown that recovery from relapses in multiple sclerosis appears to contribute to long-term outcomes, relapse recovery has largely been ignored as a treatment endpoint and predictor of disability. We hypothesized that relapse recovery in the early stages of disease will impact longer term disability.

Objectives

The first aim of this study was to identify demographic and clinical predictors associated with incomplete recovery from relapses in the first 3 years from the first MS symptom. The second aim was to examine the relationship between incomplete recovery in first 3 years and 10-year disability outcomes.

Methods

Recovery from relapses in the first three years from the first symptom was retrospectively assessed in 360 patients with relapsing remitting multiple sclerosis enrolled in the Comprehensive Longitudinal Investigations in Multiple Sclerosis at Brigham and Women’s Hospital (CLIMB study), a large longitudinal cohort. Complete or incomplete recovery from each relapse was determined based on the return of the Expanded Disability Status Scale (EDSS), Functional System Scale (FSS) and neurologic signs to baseline levels at least 6 months after symptom onset. Univariate and multivariable models were used to associate recovery with demographic and clinical factors and to predict 10-year disability and MRI outcomes (brain parenchymal fraction and T2 lesion volume).

Results

Including their initial episode, the 360 included patients had a total of 736 relapses within the first three years from their first symptom. 44.6% of these relapses had an incomplete recovery at 6 months. Relapses in untreated patients had an incomplete recovery in 51.8% of cases, compared to 28.9% in patients who were being treated with a disease modifying drug (p<0.001). In the multivariable analysis, recovery from relapses in the first 3 years was better younger patients, who were on interferon treatment, had no bowel or bladder symptoms and had a longer interval since their first symptom. For every incomplete recovery in the first three years, the EDSS at 10 years increased by 0.6 points, and the timed 25-foot walk at 10 years increased by 0.5 seconds. Both disability outcomes were also higher with older age at first symptom and higher BMI. Brain atrophy, measured by the brain parenchymal fraction on MRI, was associated only with older age at first symptom, whereas T2-hyperintense lesion volume was only associated with smoking.

Conclusions

Early initiation of first-line disease-modifying treatments can improve relapse recovery, which in turn prevents long-term disability.

Background

The gut microbiota is emerging as a critical regulator of immune responses and appears to play an important role in MS. The International Multiple Sclerosis Microbiome study (iMSMS) is a global collaboration aimed at elucidating the role of commensal gut bacteria in MS by acquiring and analyzing samples from 2000 patients and 2000 household healthy controls.

Objectives

The iMSMS focuses on identifying the microbes, genes and pathways that are involved in MS pathogenesis and on investigating how the microbiome changes response to treatment.

Methods

A total of 576 case and household healthy control pairs were recruited from 7 centers located in the US (West and East coasts), Europe and South America. Stool samples were collected and evaluated by both 16S and shallow whole metagenome shotgun sequencing. Univariate and multivariate linear regression analyses were conducted to understand patterns of variation on gut microbiome.

Results

This is the largest MS microbiome study reported to date. Our results showed a statistically significant difference of beta diversity between MS and healthy controls for the first time in MS. Intriguingly, multiple species of Akkermansia, including the known mucin-degrading bacterium Akkermansia muciniphila, were significantly enriched in untreated MS patients after adjusting for confounding factors, but the difference was not detected in treated MS group versus control. Ruminococcus torques and Eisenbergiella tayi were also among the top significantly enriched bacteria in MS. Inversely, a main butyrate producer, Faecalibacterium prausnitzii, was significantly decreased in the untreated MS group. Functional pathways of L-tryptophan biosynthesis and L-threonine biosynthesis were slightly increased in untreated MS patients, while 5-aminoimidazole ribonucleotide biosynthesis I was increased in the treated group.

Conclusions

Our large household-controlled study allowed us to identify modest but statistically robust MS-associated changes in bacterial composition and functions. It provides the foundation for all future studies of the gut microbiota in MS. The strain-level genomic variation and microbiome-derived molecules need to be further explored for understanding microbial adaptation and pathogenicity.

Background

When assessing long-term trends in disability accumulation and economic models to compare treatments in multiple sclerosis (MS), disability accumulation on the Expanded Disability Status Scale (EDSS) is commonly assumed to depend only on the present state of the patient. Such models also often assume that the probability of disability accumulation is constant over the disease course.

Objectives

The objective of this study was to assess the assumptions of models used to describe disability accumulation within patients with MS.

Methods

Patients enrolled in the Comprehensive Longitudinal Investigation of Multiple Sclerosis at Brigham and Women’s Hospital (CLIMB) who had ≥6 consecutive clinic visits, which occurred every 6 months, were included in this analysis. This yielded 7257 observations for 1039 patients. To assess whether a previous EDSS score only was sufficient for modeling disability accumulation, we compared 2 models for EDSS transitions with the EDSS scale grouped into 3 score levels (0–1.5, 2–3.5, ≥4) using a likelihood ratio test. The first transition model included only the present EDSS score, and the second model included the present and the previous EDSS scores. In addition, we fit a repeated measures proportional odds model with 1, 2, and 3 previous EDSS scores to assess if additional previous EDSS scores added to the model. To determine if the probability of disability accumulation changed with time, we assessed whether disease duration <15 years or ≥15 years was associated with a change in the transition matrix using a likelihood ratio test. Finally, we fit the repeated measures proportional odds model to assess if disease duration improved the model that included 3 previous EDSS scores.

Results

When the model with only the present EDSS score was compared with the model with 2 previous EDSS scores, the model including the 2 previous EDSS scores led to a better model fit (P<0.001). Further, all previous EDSS scores were associated with subsequent EDSS score in the repeated measures proportional odds model (1 previous EDSS, OR [95% CI]: 4.64 [4.31–4.99]; 2 previous EDSS, OR [95% CI]: 1.77 [1.65–1.90]; 3 previous EDSS, OR [95% CI]: 1.63 [1.53–1.73]). Incorporating disease duration also improved model fit using both approaches (P<0.001 for each method).

Conclusions

Additional EDSS history and disease duration may be important to incorporate into disability accumulation modeling for MS.