Peripheral helper T cells in the pathogenesis of multiple sclerosis.

BACKGROUND: Peripheral helper T cells (Tph) are likely implicated in the pathogenesis of various inflammatory diseases. Tph cells share functions with follicular helper T cells, including plasma cell differentiation and antibody production. OBJECTIVE AND METHODS: To investigate a possible role of Tph cells in the pathogenesis of multiple sclerosis (MS), we used flow cytometry to analyze the function, phenotype, and central nervous system (CNS)-recruitment of Tph cells in the blood and cerebrospinal fluid (CSF) from controls and patients with relapsing-remitting (RR) and primary progressive (PP) MS. RESULT: This study identified two functionally distinct Tph cell populations and a regulatory counterpart, Tpr cells. No differences in blood frequencies, cytokine production, or potential to interact with B cells were found between controls and patients with MS. Along with an equal CNS-migration potential, we found both Tph cell populations enriched in the CSF; and surprisingly, an increased frequency of intrathecal Tph cells in the control group compared to patients with MS. CONCLUSION: Altogether, we did not find an increased frequency of CSF Tph cells in patients with RRMS or PPMS. Our findings indicate that rather than being involved in MS pathogenesis, Tph cells may be implicated in normal CNS immunosurveillance.

Dimethyl fumarate therapy suppresses B cell responses and follicular helper T cells in relapsing-remitting multiple sclerosis.

BACKGROUND: Dimethyl fumarate (DMF) is a disease-modifying therapy used for patients with relapsing-remitting multiple sclerosis (RRMS). B cells are important contributors to the pathogenesis of RRMS, where they regulate the inflammatory immune responses and participate in development of lesions in the central nervous system (CNS). The impact of DMF on B cell subpopulations remains incompletely understood. OBJECTIVES: In this study, we evaluated the effects of DMF on B cell subpopulations and their effector functions. METHODS: Blood from 21 DMF-treated and 18 untreated patients with RRMS was analyzed by flow cytometry. RESULTS: We found that DMF reduces the frequency of circulating antigen-experienced B cells, a reduction likely related to a reduced frequency of follicular helper T (TFH) cells and an increased frequency of follicular regulatory T (TFR) cells. Studying the impact of monomethyl fumarate (MMF), the primary metabolite of DMF, on B cell effector function in vitro showed that MMF increased the frequency of transforming growth factor (TGF)-ß-producing B cells and decreased the frequency of B cells secreting lymphotoxin (LT)-α, tumor necrosis factor (TNF)-α, interleukin (IL)-6, and to a lesser extent IL-10. CONCLUSION: In summary, these data suggest an anti-inflammatory role of DMF and its metabolite MMF on the B cell compartment.

Age-corrected neurofilament light chain ratio decreases but does not predict relapse in highly active multiple sclerosis patients initiating natalizumab treatment.

BACKGROUND: Neurofilament light chain (NFL) is a biomarker for monitoring disease activity and treatment response in multiple sclerosis (MS). However, while most agree that NFL levels predict disease activity and worsening, the predictive value of NFL on future relapse risk remains uncertain. OBJECTIVE: The primary aim was to evaluate the predictive value of age-corrected serum NFL (sNFL) ratio on relapse risk in highly active relapsing-remitting MS patients (RRMS) treated with natalizumab. A secondary aim was to investigate the predictive value of sNFL ratios for MRI activity. METHODS: From January 1, 2006, to December 31, 2010, 355 patients initiated natalizumab treatment at the Danish Multiple Sclerosis Center. 305 patients were anti-natalizumab antibodies negative and had at least one blood sample available for sNFL analysis using single molecule array analysis at baseline, three, six, or 12 months. The patients were either treatment-naïve (n = 8), switching from interferon-ß or glatiramer acetate (n = 253), or switching from mitoxantrone (n = 44). An age-corrected ratio was calculated for sNFL. Time to first relapse was calculated from baseline and after re-baseline at 90 days. Data were collected from baseline until the two-year follow-up or end of treatment and included disease duration, expanded disability status scale, previous treatments, relapses 12 months prior to natalizumab initiation, smoking intensity, body mass index, and body weight. In addition, the patients underwent annual MRI of the brain. RESULTS: The sNFL ratio was increased in 173 of 287 samples (60.3 %) at baseline, in 119 of 246 samples (48.8 %) at month three, in 109 of 287 samples (38.0 %) at month six, and in 82 of 270 samples (30.4 %) at month 12. The sNFL ratio continuously declined over 12 months with significant decreases for every measuring timepoint: baseline vs. three months p = 3.0 × 10-6; three months vs. six months p = 3.2 × 10-5; six months vs. 12 months p = 0.002. Univariate Cox regression analysis showed that time to first relapse from 1) natalizumab initiation and from 2) re-baseline was associated with the number of relapses in the previous 12 months (hazard ratio 1.31 per relapse, 95 % CI = 1.2-1.5, p = 2.0 × 10-6; and 1.21 per relapse, 95 % CI = 1.1-1.4, p = 0.002, respectively). sNFL ratio at re-baseline was negatively associated with relapse risk (hazard ratio 0.82 per unit; 95 % CI = 0.7-1.0; p = 0.049). A multivariable Cox regression analysis of relapse risk from re-baseline showed that the number of relapses in the 12 months prior to natalizumab treatment (hazard ratio 1.29; 95 % CI = 1.1-1.5; p = 6.0 × 10-4) and smoking (hazard ratio 1.51 per 20 cigarettes per day; 95 % CI = 1.0-2.2; p = 0.030) were associated with increased risk of relapse; sNFL ratio was associated with a lower risk of relapse (hazard ratio = 0.736 per unit; 95 % CI = 0.6-0.9 p = 0.007). In univariate logistic regression analyses, the sNFL ratio at 12 months and values above the 75th and the 90th percentile predicted MRI activity in the following year (odds ratio [OR] = 2.0, 95 % CI = 1.2-3.6, p = 0.012; OR = 2.2, 95 % CI = 1.2-4.1, p = 0.014; and OR = 2.8, 95 % CI = 1.1-6.7, p = 0.026). CONCLUSION: In this highly active RRMS cohort, high sNFL ratios reflected previous relapse activity and decreased after initiation of treatment but were not associated with increased relapse risk in the following two years. Pre-treatment relapses and smoking on treatment were predictors of relapse risk after re-baselining at 90 days. MRI activity in year two was predicted by sNFL ratios at month 12.

Study protocol: effects of exercise booster sessions on preservation of exercise-induced adaptations in persons with multiple sclerosis, a multicentre randomised controlled trial-the MS BOOSTER trial.

INTRODUCTION: Multiple sclerosis (MS) causes a broad range of symptoms, with physical function being one of the most disabling consequences according to patients themselves. Exercise effectively improves lower extremity physical function. Nonetheless, it is unknown which exercise modality is most effective and it remains challenging to keep persons with MS adhering to exercise over a longer period. Therefore, the present study aims to investigate how exercise booster sessions (EBS) influence the sustainability of exercise-induced effects on physical function, and furthermore, to investigate which exercise modality (aerobic training or resistance training) is most effective in terms of improving physical function. MATERIALS AND METHODS: This study is a multi-arm, parallel-group, open-label multicentre randomised controlled trial investigating the effects of EBS. Participants (n=150) are initially randomised to 12 weeks of either resistance training+usual care, aerobic training+usual care or usual care. After 12 weeks of intervention, participants in the exercise groups will again be randomised to either EBS+usual care or usual care during a 40-week follow-up period. The primary outcome is physical function (composite score based on 6-min walk test and five-time sit to stand), and the secondary outcomes are fatigue, cognition, physical activity, symptoms of depression and quality of life. ETHICS AND DISSEMINATION: The study is approved by the Central Denmark Region Committees on Health Research Ethics (1-10-72-237-21) and is registered at the Danish Data Protection Agency (2016-051-000001) and at Clinicaltrials.gov (NCT04913012). All study findings will be published in scientific peer-reviewed journals and presented at scientific conferences. TRIAL REGISTRATION NUMBER: NCT04913012.

Dimethyl fumarate treatment of primary progressive multiple sclerosis: results of an open-label extension study.

INTRODUCTION: Dimethyl fumarate treatment is approved in Europe for patients with relapsing-remitting multiple sclerosis (MS) and in the US for relapsing forms of MS. We recently published the results of the first randomized placebo-controlled trial of 48 weeks of treatment with dimethyl fumarate or placebo in primary progressive MS (PPMS) (clinicaltrial.gov NCT02959658). The placebo-controlled phase of the trial did not meet its primary endpoint (reduction in cerebrospinal fluid concentrations of neurofilament light chain [NFL]). AIM: To investigate the effects of dimethyl fumarate treatment in the open-label extension phase of the trial (week 48-96), where all patients were treated with DMF. METHODS: Reported data are from screening, week 48, and week 96 visits. Patients were clinically evaluated with Expanded Disability Status Scale (EDSS), 9-Hole Peg Test (9HPT), Timed 25-Foot Walk (T25FW) test, Symbol Digit Modalities Test (SDMT), California Verbal Learning Test, and Brief Visuospatial Memory-Revised. Serum NFL concentrations were measured by single-molecule array analysis. MRI was performed on a 3 tesla MRI scanner and included: new/enlarging lesions, volume of lesions, cortical grey matter, putamen, thalamus, and normal-appearing white matter, and additional diffusion tensor imaging and magnetization transfer ratio measures. RESULTS: Forty-two patients entered the open-label treatment phase, and 33 patients (61%) had complete data sets at week 96. The remaining 39% did not complete the trial and were not evaluated at week 96. We found no evidence of differences in clinical and MRI measures between patients initially treated with dimethyl fumarate and patients initially treated with placebo from baseline to week 48 and from week 48-96, where all patients were treated with dimethyl fumarate. Serum NFL concentrations remained stable in both groups over 96 weeks. Assessed with either EDSS, T25FW, or 9HPT at week 96, progression was observed for 14 patients (45%). Interestingly, another 15 patients (46%) had improvement in one or more of these domains. Applying a cut-off of 8 points, 2 (6%) patients worsened on SDMT, 25 (78%) did not change, and 5 (16%) improved. CONCLUSIONS: Dimethyl fumarate treatment showed no effects on neither clinical nor MRI outcomes or changes in serum concentrations of NFL. An expected number of patients showed evidence of progression on standard clinical scales; however, this was matched by an equal number of patients improving. The reasons for the physical improvement in an unexpectedly high proportion of patients must be addressed in future studies.

Relationship between cerebrospinal fluid biomarkers of inflammation and tissue damage in primary progressive multiple sclerosis.

BACKGROUND AND OBJECTIVES: It is unclear to what extent intrathecal inflammation contributes to the pathogenesis in primary progressive multiple sclerosis (PPMS). We conducted an exploratory study to investigate the degree of intrathecal inflammation and its association with biomarkers of disease activity and severity in patients with PPMS. METHODS: We included patients with PPMS who participated in a randomized controlled trial conducted at the Danish Multiple Sclerosis Center, patients with relapsing-remitting multiple sclerosis (RRMS) and healthy controls. We analyzed concentrations of a panel of cytokines in CSF using electrochemiluminescence assays. We then explored the relationship between cytokines found in increased CSF concentrations in patients with PPMS (compared with healthy controls) with CSF concentrations of neurofilament light chain (NFL) and myelin basic protein (MBP), IgG-index, and magnetic resonance imaging (MRI) metrics (volume, magnetization transfer ratio and diffusion tensor imaging) from lesions, normal-appearing white matter, and cortical grey matter. RESULTS: We included 59 patients with PPMS, 40 patients with RRMS, and 21 healthy controls. In patients with PPMS, CSF concentrations of CC chemokine ligand 3 (CCL-3), CXC chemokine ligand 8 (CXCL-8), CXCL-10, interleukin (IL)-10, IL-15, and vascular endothelial growth factor (VEGF)-A were increased compared with healthy controls and comparable with CSF concentrations in patients with RRMS. In addition, patients with PPMS had increased CSF concentrations of IL-12p40, IL-17A, tumor necrosis factor (TNF)-α, and lymphotoxin (LT)-α compared with healthy controls, but concentrations of these cytokines were even higher in patients with RRMS. For the remaining seven cytokines (CCL22, interferon-γ, IL-5, IL-7, IL-16, IL-22, IL-27), we found no difference between patients with PPMS and healthy controls. CSF concentrations of NFL and MBP correlated weakly with concentrations of IL-15, while the remaining proinflammatory cytokines were not associated with CSF concentrations of NFL or MBP. The IgG-index correlated with four cytokines (IL-10, IL-12p40, TNF-α, and LT-α). We did not observe any significant associations between MRI metrics and CSF biomarkers of inflammation. DISCUSSION: In this exploratory study, we found few and weak associations between intrathecal inflammation and the extent of neuroaxonal damage and demyelination, and no associations between intrathecal inflammation and MRI metrics, in patients with PPMS. Our findings suggest that, for patients with PPMS, these measures of intrathecal inflammation are not associated with the extent of neuroaxonal injury, demyelination, and disease severity, and these processes may therefore have less relevance in PPMS than in relapsing forms of MS.

Increased Intrathecal Activity of Follicular Helper T Cells in Patients With Relapsing-Remitting Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Follicular helper T (Tfh) cells play a critical role in protective immunity helping B cells produce antibodies against foreign pathogens and are likely implicated in the pathogenesis of various autoimmune diseases. The purpose of this study was to investigate the role of Tfh cells in the pathogenesis of multiple sclerosis (MS). METHODS: Using flow cytometry, we investigated phenotype, prevalence, and function of Tfh cells in blood and CSF from controls and patients with relapsing-remitting MS (RRMS) and primary progressive MS (PPMS). In addition, an in vitro blood-brain barrier coculture assay of primary human astrocytes and brain microvascular endothelial cells grown in a Boyden chamber was used to assess the migratory capacity of peripheral Tfh cells. RESULTS: This study identified 2 phenotypically and functionally distinct Tfh cell populations: CD25- Tfh cells (Tfh1-like) and CD25int Tfh cells (Tfh17-like). Whereas minor differences in Tfh cell populations were found in blood between patients with MS and controls, we observed an increased frequency of CD25- Tfh cells in CSF of patients with RRMS and PPMS and CD25int Tfh cells in patients with RRMS, compared with controls. Increasing frequencies of CSF CD25- Tfh cells and the CD25- Tfh/Tfr ratio scaled with increasing IgG index in patients with RRMS. Despite an increased prevalence of intrathecal Tfh cells in patients with MS, no difference in the migratory capacity of circulating Tfh cells was observed between controls and patients with MS. Instead, CSF concentrations of CXCL13 scaled with total counts of Tfh and Tfr cell subsets in the CSF. DISCUSSION: Our study indicates substantial changes in intrathecal Tfh dynamics, particularly in patients with RRMS, and suggests that the intrathecal inflammatory environment in patients with RRMS promotes recruitment of peripheral Tfh cells rather than the Tfh cells having an increased capacity to migrate to CNS.

Dimethyl Fumarate Treatment in Patients With Primary Progressive Multiple Sclerosis: A Randomized, Controlled Trial.

BACKGROUND AND OBJECTIVE: To study whether dimethyl fumarate is superior to placebo in decreasing CSF concentrations of neurofilament light chain (NFL) in patients with primary progressive MS (PPMS). METHODS: In the double-blind, placebo-controlled phase 2 study dimethyl FUMArate treatment in Progressive Multiple Sclerosis (FUMAPMS), patients with PPMS were randomly assigned to treatment with 240 mg dimethyl fumarate or placebo in a 1:1 ratio for 48 weeks. The primary endpoint was change in concentration of NFL in the CSF. Secondary endpoints included other CSF biomarkers and clinical and MRI measures. Efficacy was evaluated for the full data set by multiple imputations to account for missing data. Safety was assessed for the full data set. RESULTS: Fifty-four patients (mean age 54.9 years [SD 6.1], median Expanded Disability Status Scale 4.0 [nterquartile range 4.0-6.0], disease duration 14.1 [SD 9.4], and 21 [39%] female) were randomized to either placebo (n = 27) or dimethyl fumarate (n = 27) therapy. At screening CSF concentrations, adjusted for age and sex, of NFL, myelin basic protein (MBP), soluble CD27, chitinase 3-like 1, and B-cell maturation antigen were higher than in a group of symptomatic controls. Twenty-six patients (96%) in the dimethyl fumarate group and 24 patients (89%) in the placebo group completed the randomized phase. Mean change in CSF concentrations of NFL did not differ between groups (mean difference 99 ng/L; 95% CI -292 to 491 ng/L). MBP in CSF decreased in the treatment group (-182 ng/L, 95% CI -323 to -41 ng/L compared with placebo). The difference observed in the multiple imputation data set was not significant in a per protocol analysis. This was nominally significant in the multiple imputation data set but not in the per protocol analysis This was not found in the per protocol analysis Other secondary and tertiary outcomes were not affected. Various infections, lymphopenia, flushing, and gastrointestinal side effects were more frequent in the dimethyl fumarate group. Serious adverse events were similar between groups. DISCUSSION: Dimethyl fumarate treatment for 48 weeks had no effect on any of the investigated efficacy measures in patients with PPMS. We did not observe adverse events not anticipated for dimethyl fumarate treatment. TRIAL REGISTRATION INFORMATION: Clinicaltrials.gov identifier NCT02959658. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for patients with PPMS, dimethyl fumarate treatment has no effect on CSF NFL levels compared with placebo treatment.

Dimethyl fumarate therapy reduces memory T cells and the CNS migration potential in patients with multiple sclerosis.

BACKGROUND: Dimethyl fumarate (DMF) is a disease-modifying therapy for patients with relapsing-remitting multiple sclerosis (RRMS). T cells are major contributors to the pathogenesis of RRMS, where they regulate the pathogenic immune response and participate in CNS lesion development. OBJECTIVES: In this study we evaluate the therapeutic effects of DMF on T cell subpopulations, their CNS migration potential and effector functions. METHODS: Blood and CSF from untreated and DMF-treated patients with RRMS and healthy donors were analyzed by flow cytometry. RESULTS: DMF reduced the prevalence of circulating proinflammatory CD4+ and CD8+ memory T cells, whereas regulatory T cells were unaffected. Furthermore, DMF reduced the frequency of CD4+ T cells expressing CNS-homing markers. In coherence, we found a reduced recruitment of CD4+ but not CD8+ T cells to CSF. We also found that monomethyl fumarate dampened T cell proliferation and reduced the frequency of TNF-α, IL-17 and IFN-γ producing T cells. CONCLUSION: DMF influences the balance between proinflammatory and regulatory T cells, presumably favoring a less proinflammatory environment. DMF also reduces the CNS migratory potential of CD4+ T cells whereas CD8+ T cells are less affected. Altogether, our study suggests an anti-inflammatory effect of DMF mainly on the CD4+ T cell compartment.

Progressive multiple sclerosis, cognitive function, and quality of life.

Background: Patients with progressive multiple sclerosis (MS) often have cognitive impairment in addition to physical impairment. The burden of cognitive and physical impairment progresses over time, and may be major determinants of quality of life. The aim of this study was to assess to which degree quality of life correlates with physical and cognitive function in progressive MS. Methods: This is a retrospective study of 52 patients with primary progressive (N = 18) and secondary progressive MS (N = 34). Physical disability was assessed using the Expanded Disability Status Scale, Timed 25 Foot Walk (T25FW) test and 9-Hole Peg Test (9HPT). Cognitive function was assessed using Symbol Digit Modalities Test (SDMT), Paced Auditory Serial Addition Test, and Trail Making Test B (TRAIL-B). In addition, quality of life was assessed by the Short Form 36 (SF-36) questionnaire. Results: Only measures of cognitive function correlated with the overall SF-36 quality of life score and the Mental Component Summary score from the SF-36. The only physical measure that correlated with a measure of quality of life was T25FW test, which correlated with the Physical Component Summary from the SF-36. We found no other significant correlations between the measures of cognitive function and the overall physical measures but interestingly, we found a possible relationship between the 9HPT score for the nondominant hand and the SDMT and TRAIL-B. Conclusion: Our findings support inclusion of measures of cognitive function in the assessment of patients with progressive MS as these correlated closer with quality of life than measures of physical impairment.