Found 6 Presentations For Request "LB01.03"

Biomarkers and Bioinformatics Late Breaking Abstracts

LB01.03 - Neutrophil granulocyte markers in cerebrospinal fluid differentiate NMOSD and anti-MOG antibody associated disease from MS in acute disease phase

Speakers
Presentation Number
LB01.03
Presentation Topic
Biomarkers and Bioinformatics
Lecture Time
09:24 - 09:36

Abstract

Background

Background
Neuromyelitis optica spectrum disorders (NMOSD), anti-MOG-antibody associated disease (MOGAD) and multiple sclerosis (MS) may be difficult to differentiate. Detection of antibodies (Ab) targeting AQP4 and MOG is the diagnostic gold standard for the former two diseases, but has limited sensitivity and long laboratory turnaround time. Neutrophil granulocyte (NG) invasion of brain tissue is a key differentiator of NMOSD from MS, and has also been described in MOGAD.

Objectives

Objectives
To examine the capability to differentiate NMOSD/MOGAD from MS by the profile of secreted primary (elastase (Ela); myeloperoxidase (MPO)) and secondary (matrix metalloproteinase-8 (MMP-8); neutrophil gelatinase-associated lipocalin (NGAL)) neutrophil granule products in CSF.

Methods

Methods
CSF from patients with NMOSD (n=42), MOGAD (n=6) and RRMS (n=41) were evaluated for Ela, MPO, MMP-8, NGAL, and compared with markers of neuronal (NfL) and astrocyte (GFAP, S100B) damage by conventional ELISA or single molecule array assay. CSFs from healthy controls (HC) (n=25) served as reference. The association between biomarkers and disease groups was assessed in linear models. The kinetic change of biomarkers in function of time since last relapse was modelled across disease groups. ROC curves and area under the curve (AUC) were calculated to estimate the potential to differentiate NMOSD/MOGAD from RRMS in acute disease phase (≤20 days after relapse), as well as between acute NMOSD and MOGAD. The association of biomarkers with EDSS in acute NMOSD and RRMS was assessed by linear models and Spearman correlation.

Results

Results
All disease groups had elevated NfL vs HC (p<0.01), while GFAP levels were increased only in NMOSD (p<0.01). In acute NMOSD, all 4 NG markers were increased vs HC and acute RRMS (all p<0.01). In MOGAD, Ela, MPO and MMP-8 were increased vs HC (p<0.025) and acute RRMS (p<0.04). AUC in ROC analyses comparing acute NMOSD/MOGAD vs acute RRMS was high (Ela and NGAL: 0.91; MPO: 0.82; MMP-8: 0.81). In acute NMOSD, S100B and GFAP levels were increased in 89% (AUC=0.82) and 83% (AUC=0.80) of patients, respectively, vs median values of MOGAD. In acute NMOSD, EDSS scores correlated with all 4 NG markers (all p<0.01), and GFAP (p<0.031), but not with NfL and S100B (both p=0.21).

Conclusions

Conclusion
NG-specific biomarkers correlate with current EDSS scores in NMOSD. They show high sensitivity and specificity for rapid differentiation of acute NMOSD and MOGAD vs RRMS, similar to those reported for Ab against AQP4 and MOG. As the 4 NG biomarkers can be measured within few hours, as compared to an up to 2-week turnaround time for gold-standard cell-based assays for AQP4 and MOG, they could support individual decision making for acute therapeutic intervention. Further, increased S100B and GFAP levels differentiate acute NMOSD from MOGAD. NG markers may have a role in the diagnosis of Ab-negative NMOSD.

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Imaging Late Breaking Abstracts

LB01.04 - Brain microstructural and metabolic alterations detected in vivo at the onset of the first demyelinating event.

Speakers
Presentation Number
LB01.04
Presentation Topic
Imaging
Lecture Time
09:36 - 09:48

Abstract

Background

In early multiple sclerosis, a clearer understanding of normal-brain tissue microstructural and metabolic abnormalities will provide valuable insights into its pathophysiology. Here, we studied the brain of patients with their first demyelinating episode using neurite orientation dispersion and density imaging (NODDI), for information about neuro-axonal density and spatial distribution, and 23Na MRI, for total sodium concentration reflecting neuro-axonal metabolic dysfunction and loss.

Objectives

To detect, using a multi-parametric quantitative MRI approach, clinically relevant alterations in the brain of early patients not captured by conventional MRI.

Methods

We enrolled 42 patients with clinically isolated syndrome or multiple sclerosis within 3 months from the onset and 16 healthy controls. We assessed physical and cognitive scales. On a 3T scanner, we acquired brain and spinal cord structural scans, and brain NODDI. Thirty-two patients and 13 healthy controls also underwent brain 23Na MRI. In the brain normal-appearing white matter, white matter lesions, and grey matter, we measured, from NODDI, the neurite density index (NDI), a marker of neuro-axonal density, and the orientation dispersion index (ODI), reflecting the fanning and crossing of neurites, and, from 23Na MRI, the TSC. We used linear regression models, adjusted for brain parenchymal fraction and lesion load, and Spearman correlation tests. For robust regression estimates, we used a p≤0.01.

Results

Patients showed higher ODI in normal-appearing white matter, including the corpus callosum, where they also showed lower NDI and higher TSC, compared with controls. In grey matter, compared with controls, patients had lower ODI in frontal, parietal and temporal cortex; lower NDI in parietal, temporal and occipital cortex; and higher TSC in limbic and frontal cortex. Brain volumes did not differ between patients and controls. In patients, higher ODI in corpus callosum was associated with worse performance on timed walk test (p=0.009, B=0.01, 99% Confidence Interval=0.0001-0.02), independent of brain and lesion volumes. Higher TSC in left frontal middle gyrus was associated with higher disability on Expanded Disability Status Scale (rs=0.5, p=0.005).

Conclusions

We found increased axonal dispersion in normal-appearing white matter, particularly corpus callosum, where we found also reduced axonal density and total sodium accumulation suggesting that this structure can be early affected by neurodegeneration. The association between increased axonal dispersion in the corpus callosum and worse walking performance implies that morphological and metabolic alterations in this structure may contribute to disability in multiple sclerosis. Brain volumes were neither altered nor related to disability in patients, so these two advanced MRI techniques can be more sensitive at detecting clinically relevant pathology in very early multiple sclerosis.

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Microbiome Late Breaking Abstracts

LB01.05 - Network analysis identifies gut bacteria associated with multiple sclerosis relapse among pediatric-onset patients

Abstract

Background

Commensal gut microbes are known to affect host immune function and may be modifiable. Recent work suggests gut microbiota composition contributes to onset of MS; however, little is known about its contribution to MS disease activity.

Objectives

Estimate the association between gut microbiota and subsequent disease activity among individuals with pediatric-onset MS (pedMS) from the U.S. Network of Pediatric MS Centers.

Methods

Stool samples were collected from cases (MS symptom onset <18 years) and profiled using 16S rRNA sequencing of the V4 region. Amplicon sequence variants (ASVs) were identified using the Divisive Amplicon Denoising Algorithm-2 (DADA2). ASVs present in <20% of samples were removed. ASV clusters (modules) were identified using weighted genetic correlation network analysis (WGCNA) and sparCC transformation of ASV abundance. Cox proportional hazard recurrent event models were used to examine the relationship between individual ASVs and then ASV clusters, adjusted for age, sex, and disease modifying therapy (DMT) use.

Results

Of 53 pedMS cases, 72% were girls. At stool sample collection, the mean age was 15.5 years (SD: 2.7) and disease duration was 1.1 years (SD: 1.0). Less than half (45%) had one relapse and 30% had >1 relapse over the subsequent mean follow-up of 2.5 years (SD:1.3). Over this time, 91% used a DMT. Among 270 individual ASVs included in the analyses, 20 were nominally significant (p<0.05), e.g. the presence of Blautia stercoris was associated with higher relapse risk (hazard ratio [HR]=2.50; 95% confidence interval [CI]=1.43, 4.37). WGCNA identified 6 ASV modules. Higher values of one module’s eigengene was significantly (false discovery rate q<0.2) associated with higher relapse risk (HR=1.23, 95% CI=1.02, 1.50). Four ASVs nominally associated with higher relapse risk were in this module. These included Blautia massiliensis, Dorea longicatena, Coprococcus comes, and an unknown species in genus Subdoligranulum.

Conclusions

We found that a high relative abundance of a gut microbiota species within the Blautia genus, and its interconnected variants, was associated with a higher relapse risk in pedMS cases. While our study represents the largest of its kind in MS, findings need to be replicated. However, Blautia stercoris has been linked to disease activity in other immune-mediated diseases such as systemic lupus erythematosus.

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Reproductive Aspects and Pregnancy Late Breaking Abstracts

LB01.06 - Interrupting disease modifying treatment for pregnancy in multiple sclerosis – effect on disease activity and serum neurofilament light chain

Speakers
Presentation Number
LB01.06
Presentation Topic
Reproductive Aspects and Pregnancy
Lecture Time
10:00 - 10:12

Abstract

Background

Pregnancy in MS typically goes along with reduced disease activity in the third trimester, followed by an increase in relapse frequency postpartum. Neurofilament light chain levels in serum (NfL) is a specific biomarker of neuroaxonal injury. Increased NfL levels are associated with relapses and MRI activity, while disease modifying treatment (DMT) response is reflected by a decrease of NfL.

Objectives

The objective of this study was to evaluate whether interrupting DMT due to pregnancy leads to increased NfL levels in MS.

Methods

We investigated prospectively documented pregnancies in the Swiss MS Cohort Study. Serum samples were collected 6- or 12-monthly and were analyzed by Simoa NF-light® assay. Uni- and multivariable mixed effect models were used to investigate associations between clinical characteristics and longitudinal NfL levels.

Results

We investigated 72 pregnancies in 63 relapsing MS patients (median age 31.4; disease duration 7.1 years; EDSS 1.5 at last visit before birth). In total, 433 samples were included: 92 during pregnancy or up to initiation of DMT but max. 9 months postpartum (pregnancy/post-partum period, pp), 167 prior to pp and 174 after the pp. Four patients had no DMT before, during and after pregnancy. DMT was continued in 13/72 pregnancies (>6 months during pregnancy: 6 rituximab/ocrelizumab, 4 natalizumab, 1 interferon-beta 1a i.m., 1 fingolimod and 1 glatiramer acetate). In univariable analysis, NfL levels were on average 22% higher during vs. outside the pp (β: 1.22, 95%CI: 1.10-1.35; p<0.001). We observed 29 relapses during the pp. In a multivariable analysis, relapses (within 120 days before serum sampling) were associated with 98% higher NfL (β: 1.98, 95%CI: 1.75-2.25; p<0.001); NfL was 7% higher per EDSS step increase (β: 1.07, 95%CI: 1.01-1.12; p=0.013) and on average 13% higher during vs. outside the pp (β: 1.13, 95%CI: 1.03-1.24; p=0.009). The effect of the pp on NfL disappeared after including DMT exposure (yes/no) at the sampling timepoint to the model (β:1.07, 95%CI: 0.97-1.18; p=0.178). Patients sampled during DMT had on average 12% lower NfL levels compared to patients without (β:0.88, 95%CI: 0.79-0.98; p=0.019).

Conclusions

Higher NfL levels were found during pp. This increase was independent of relapses suggesting increased subclinical disease activity during this time span. After including DMT into the model the effect of pregnancy on NfL disappeared: strategies allowing to continue DMT during pregnancy may be warranted.

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Neuroprotection, Regeneration and/or Remyelination Late Breaking Abstracts

LB01.01 - Primary astrocytopathy has a detrimental effect on remyelination efficacy of parenchymal oligodendrocyte precursor cells.

Speakers
Presentation Number
LB01.01
Presentation Topic
Neuroprotection, Regeneration and/or Remyelination
Lecture Time
09:00 - 09:12

Abstract

Background

Astrocytic impairment is a common feature of neuromyelitis optica and possibly also multiple sclerosis (MS) lesions and initiates even prior to demyelination. Repopulation of early active plaques with aquaporin 4-negative astrocyte precursors has been recorded, implying astrocytic loss in pre-active lesion stages.

Objectives

Therefore, we aimed at investigating effects of a primary astrocytic loss on lesion regeneration and remyelination.

Methods

Osmolytic shifts induce severe astrocytic loss in certain CNS regions, leading to a secondary oligodendrocyte loss and demyelination, in the absence of antigen-specific lymphocyte activation. In patients, this is referred to as central pontine myelinolysis (CPM). Studying autopsy material from patients with CPM, as well as an experimental rat model, we characterized the oligodendrocyte precursor cell (OPC) activation and differentiation. Using injections of the thymidine-analogue BrdU, we traced the maturation of OPCs activated in early lesions.

Results

Animal experiments revealed rapid activation of the parenchymal NG2+ OPC reservoir in the widely astrocyte-free lesion, leading to extensive OPC proliferation. One week after lesion initiation, most cells derived from parenchymal OPCs expressed breast carcinoma amplified sequence 1 (BCAS1), indicating the transition into a pre-myelinating state. Though, cells derived from the early parenchymal response often presented a dysfunctional morphology with condensed cytoplasm and without evidence for process extension, that were sparsely found among myelin producing or mature oligodendrocytes. Correspondingly, also early human CPM lesions showed reduced astrocyte numbers and non-myelinating BCAS1+ oligodendrocytes with dysfunctional morphology. In the animal model, neural stem cells (NSCs) located in the subventricular zone (SVZ) were activated while the lesion was already repopulated with OPCs, giving rise to nestin+ progenitors that partially generated oligodendroglial lineage cells in the lesion, that was finally successively refilled with astrocytes and remyelinated. Those nestin+ stem cell-derived progenitors were absent in human CPM cases possibly contributing to the rather inefficient lesion repair.

Conclusions

The present study underpins the importance of astrocyte-oligodendrocyte interactions for remyelination, thus stressing the necessity to further determine the impact of astrocyte dysfunction on remyelination efficiency in demyelinating disorders like MS.

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Clinical Trials Late Breaking Abstracts

LB01.02 - Phase 2 clinical trial evidence that a retinoid-X receptor agonist promotes remyelination in people with relapsing-remitting multiple sclerosis

Abstract

Background

Retinoid acid X receptor [RXR] gamma agonists promote oligodendrocyte progenitor cell differentiation and remyelination following experimental demyelination.

Objectives

To assess the safety and efficacy of bexarotene, a non-specific RXR agonist licensed for cutaneous T-cell lymphoma, as a remyelinating therapy in people with relapsing remitting multiple sclerosis.

Methods

In a double-blind, placebo-controlled, phase 2a trial (Cambridge Centre for Myelin Repair: CCMR-One), participants aged 18-50 years with relapsing remitting multiple sclerosis, stable on dimethyl fumarate for at least 6 months, were randomised to bexarotene 300mg/m2 or placebo for 6 months. The primary efficacy outcome was change in mean lesional magnetisation transfer ratio (MTR) for lesions whose baseline MTR was below the median lesional MTR for that patient. The secondary efficacy outcome was change in full-field visual evoked potential (VEP) latency in eyes with electrophysiological evidence of optic neuropathy (baseline latency >118ms). We analysed by intention to treat.

Results

52 patients were randomised 1:1 to receive six months of bexarotene or placebo. Two placebo patients withdrew before receiving study drug and one bexarotene patient withdrew consent during the trial. All bexarotene patients experienced adverse effects, notably central hypothyroidism (26 [100%]) and hypertriglyceridaemia (24 [92%, mean maximum of 6.79 mmol/L ,SD 4.4]; as well as rash (13 [50%]) and neutropenia (10 [38%]). Two discontinued placebo because of adverse events and five discontinued bexarotene because of rash [2], neutropenia, triglyceridaemia and mood disturbance. The primary efficacy outcome was negative (mean submedian lesion MTR change was 0.25pu in the bexarotene group versus 0.09pu in the placebo group, p=0.54), but in an exploratory, lesion-level analysis, though treatment difference in submedian lesions was too small to achieve significance, it was statistically significantly greater than in supermedian lesions (p=0·007). This suggests that bexarotene has a biological effect on MTR and that this effect is dependent on baseline lesional MTR. This interpretation is supported by the finding that bexarotene treatment reduced full field visual evoked potential latency compared to placebo in the 52 eyes with delayed VEPS at baseline, by 4·66 ms/eye (95% CI -8·38 -0·93; p=0·014) and in all eyes, by a per-protocol analysis, by 4.02ms/eye (P=0.015).

Conclusions

Despite a negative primary efficacy outcome, evidence from both magnetisation transfer ratio imaging and visual evoked potentials suggest that a retinoic X receptor agonist, bexarotene, promotes remyelination in people with multiple sclerosis. We have also a heterogeneous response of MS lesions to a drug promoting remyelination. Although bexarotene’s safety profile precludes its widespread use, these data support efforts to develop a selective RXR-gamma agonist.

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