Search

Abstract Cognitive impairment is the most frequent symptom reported in post-COVID-19 syndrome (PCS). Aetiology of cognitive impairment in PCS is still to be determined. Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) are increased in acute COVID-19. Their role as biomarkers in other neurological disorders is under debate. We analysed serum levels of NfL and GFAP as markers for neuronal and astrocytic damage in 53 patients presenting to a PCS Neurology outpatient clinic. Only individuals with self-reported cognitive complaints were included. In these individuals, cognitive complaints were further assessed by comprehensive neuropsychological assessment (NPA). Patients were categorized into subgroups of subjective cognitive decline, single domain impairment, or multi-domain impairment. Serum NfL was in normal range, however an increase of serum GFAP was detected in 4% of patients. Serum NfL and GFAP levels correlated with each other, even when adjusting for patient age (r = 0.347, p = 0.012). NPA showed deficits in 70%; 40% showing impairment in several tested domains. No significant differences were found between serum NfL- and GFAP-levels comparing patients with subjective cognitive decline, single domain impairment, or multi-domain impairment. Persistent neuronal or astrocytic damage did not correlate with cognitive impairment in PCS.

Abstract Objective Mechanical thrombectomy (MT) has become standard treatment in acute ischemic stroke due to large vessel occlusion (LVO). However, optimal blood pressure (BP) management following successful recanalization remains unclear. We aim to investigate the association of strictly achieving BP targets of ≤160/90 mmHg with the extent of neuronal loss and functional outcome. Methods In patients prospectively enrolled in the Gutenberg‐Stroke‐Study (May 2018–November 2019), BP was measured half‐hourly for 24 h following MT. Based on achieving BP target of ≤160/90 mmHg, patients with successful recanalization of LVO were divided into “low‐BP” group (BP ≤ 160/90 mmHg) or “high‐BP” group (BP > 160/90 mmHg). Neuronal loss was quantified by serum‐based measurement of neurofilament light chain (sNfL) after three days. BP groups and association of BP parameters with sNfL were investigated by correlation analyses and multiple regression modeling. Results Of 253 enrolled patients (mean age 73.1 ± 12.9 years, 53.4% female), 165 met inclusion criteria. 21.2% (n = 35) strictly achieved “low‐BP” target. “low‐BP” was associated with unfavorable functional outcome at 90‐day follow‐up (aOR [95%CI]: 5.88 [1.88–18.32], p = 0.002) and decreased health‐related quality of life (mean EQ‐5D‐index 0.45 ± 0.28 vs 0.63 ± 0.31, p = 0.009). sNfL levels were increased in “low‐BP” patients (median [IQR] 239.7 [168.4–303.4] vs 118.8 [52.5–220.5] pg/mL, p = 0.026). Hypotensive episodes were more frequent in the “low‐BP” group (48.6% vs 29.2%, p = 0.031). sNfL level could identify patients who had experienced hypotensive episodes with high discriminative ability (AUC [95%CI]: 0.68 [0.56–0.78], p = 0.007). Interpretation Strict BP control (≤160/90 mmHg) within 24 h following successful recanalization of LVO by MT is associated with increased neuronal injury, displayed by higher sNfL levels, and poorer functional outcome, potentially indicating hypotension‐induced neuronal loss during post‐MT phase.

Abstract Objective Ongoing neuroaxonal damage is a major contributor to disease progression and long-term disability in multiple sclerosis. However, spatio-temporal distribution and pathophysiological mechanisms of neuroaxonal damage during acute relapses and later chronic disease stages remain poorly understood. Methods Here, we applied immunohistochemistry, single-molecule array, spatial transcriptomics, and microglia/axon co-cultures to gain insight into spatio-temporal neuroaxonal damage in experimental autoimmune encephalomyelitis (EAE). Results Association of spinal cord white matter lesions and blood-based neurofilament light (sNfL) levels revealed a distinct, stage-dependent anatomical pattern of neuroaxonal damage: in chronic EAE, sNfL levels were predominately associated with anterolateral lumbar lesions, whereas in early EAE sNfL showed no correlation with lesions in any anatomical location. Furthermore, neuroaxonal damage in late EAE was largely confined to white matter lesions but showed a widespread distribution in early EAE. Following this pattern of neuroaxonal damage, spatial transcriptomics revealed a widespread cyto- and chemokine response at early disease stages, whereas late EAE was characterized by a prominent glial cell accumulation in white matter lesions. These findings were corroborated by immunohistochemistry and microglia/axon co-cultures, which further revealed a strong association between CNS myeloid cell activation and neuroaxonal damage both in vivo and in vitro. Interpretation Our findings indicate that CNS myeloid cells may play a crucial role in driving neuroaxonal damage in EAE. Moreover, neuroaxonal damage can progress in a stage-dependent centripetal manner, transitioning from normal-appearing white matter to focal white matter lesions. These insights may contribute to a better understanding of neurodegeneration and elevated sNfL levels observed in multiple sclerosis patients at different disease stages. Graphical Abstract

Abstract Background Extracellular vesicles (EVs) originating from the central nervous system (CNS) can enter the blood stream and carry molecules characteristic of disease states. Therefore, circulating CNS-derived EVs have the potential to serve as liquid-biopsy markers for early diagnosis and follow-up of neurodegenerative diseases and brain tumors. Monitoring and profiling of CNS-derived EVs using multiparametric analysis would be a major advance for biomarker as well as basic research. Here, we explored the performance of a multiplex bead-based flow-cytometry assay (EV Neuro) for semi-quantitative detection of CNS-derived EVs in body fluids. Methods EVs were separated from culture of glioblastoma cell lines (LN18, LN229, NCH82) and primary human astrocytes and measured at different input amounts in the MACSPlex EV Kit Neuro, human. In addition, EVs were separated from blood samples of small cohorts of glioblastoma (GB), multiple sclerosis (MS) and Alzheimer’s disease patients as well as healthy controls (HC) and subjected to the EV Neuro assay. To determine statistically significant differences between relative marker signal intensities, an unpaired samples t-test or Wilcoxon rank sum test were computed. Data were subjected to tSNE, heatmap clustering, and correlation analysis to further explore the relationships between disease state and EV Neuro data. Results Glioblastoma cell lines and primary human astrocytes showed distinct EV profiles. Signal intensities were increasing with higher EV input. Data normalization improved identification of markers that deviate from a common profile. Overall, patient blood-derived EV marker profiles were constant, but individual EV populations were significantly increased in disease compared to healthy controls, e.g. CD36+EVs in glioblastoma and GALC+EVs in multiple sclerosis. tSNE and heatmap clustering analysis separated GB patients from HC, but not MS patients from HC. Correlation analysis revealed a potential association of CD107a+EVs with neurofilament levels in blood of MS patients and HC. Conclusions The semi-quantitative EV Neuro assay demonstrated its utility for EV profiling in complex samples. However, reliable statistical results in biomarker studies require large sample cohorts and high effect sizes. Nonetheless, this exploratory trial confirmed the feasibility of discovering EV-associated biomarkers and monitoring circulating EV profiles in CNS diseases using the EV Neuro assay. Video Abstract

Post-acute COVID-19 vaccination syndrome (PACVS) is a chronic disease triggered by SARS-CoV-2 vaccination (estimated prevalence 0.02%). PACVS is discriminated from the normal post-vaccination state by altered receptor antibodies, most notably angiotensin II type 1 and alpha-2B adrenergic receptor antibodies. Here, we investigate the clinical phenotype using a study registry encompassing 191 PACVS-affected persons (159 females/32 males; median ages: 39/42 years). Unbiased clustering (modified Jaccard index) of reported symptoms revealed a prevalent cross-cohort symptomatology of malaise and chronic fatigue (>80% of cases). Overlapping clusters of (i) peripheral nerve dysfunction, dysesthesia, motor weakness, pain, and vasomotor dysfunction; (ii) cardiovascular impairment; and (iii) cognitive impairment, headache, and visual and acoustic dysfunctions were also frequently represented. Notable abnormalities of standard serum markers encompassing increased interleukins 6 and 8 (>80%), low free tri-iodine thyroxine (>80%), IgG subclass imbalances (>50%), impaired iron storage (>50%), and increased soluble neurofilament light chains (>30%) were not associated with specific symptoms. Based on these data, 131/191 participants fit myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and simultaneously also several other established dysautonomia syndromes. Furthermore, 31/191 participants fit none of these syndromes. In conclusion, PACVS could either be an outlier of ME/CFS or a dysautonomia syndrome sui generis.

BackgroundCombination treatment with BRAF/MEK inhibitors favorably impact progression-free survival in malignant melanoma. However, it may cause paradoxical activation of the MAPK/ERK pathway in immune cells without BRAF mutation, which may lead to over activation of the immune system, especially in patients with pre-existing autoimmune conditions. In this case report, treatment of malignant melanoma with BRAF/MEK inhibitors was associated with radiological disease exacerbation of pre-existing multiple sclerosis (MS).Case presentationA 47-year-old patient with pre-existing MS was diagnosed with malignant melanoma in June 2020. Anti-tumor treatment was initiated with a combination therapy of BRAF inhibitor dabrafenib and MEK inhibitor trametinib. In February 2022, the patient presented at our neurological clinic after routine MRI revealed exacerbation of radiological MS disease activity with ten new and gadolinium-enhancing lesions, and concomitant high levels of neurofilament light chain (NfL) in serum, a marker for axonal damage. In-depth analysis of immune cells in both peripheral blood and cerebrospinal fluid was performed by multi-color flow cytometry. After treatment with the B cell-depleting antibody ocrelizumab, MS disease stability was obtained and anti-tumor medication could be continued.ConclusionsImmunomodulatory treatment in cancer patients is highly effective from an oncological point of view, but may be associated with autoimmune side effects. This is of special importance in patients with pre-existing autoimmune diseases, as reflected by our case of MS disease reactivation under treatment with BRAF/MEK inhibitors. In our case, sequential modulation of immune cell subsets by B cell depletion, associated with marked shifts in B and T cell subsets, allowed for stabilization of disease and continuation of anti-tumor treatment.

Abstract Background Impaired cerebrospinal fluid (CSF) homeostasis is central to the pathogenesis of idiopathic intracranial hypertension (IIH), although the precise mechanisms involved are still not completely understood. The aim of the current study was to assess the CSF/serum ratio of neurofilament light chain levels (QNfL) as a potential indicator of functional CSF outflow obstruction in IIH patients. Methods NfL levels were measured by single molecule array in CSF and serum samples of 87 IIH patients and in three control groups, consisting of 52 multiple sclerosis (MS) patients with an acute relapse, 21 patients with an axonal polyneuropathy (PNP), and 41 neurologically healthy controls (HC). QNfL was calculated as the ratio of CSF and serum NfL levels. Similarly, we also assessed the CSF/serum ratio of glial fibrillary acidic protein (QGFAP) levels to validate the QNfL data. Routine CSF parameters including the CSF/serum albumin ratio (QAlb) were determined in all groups. Lumbar puncture opening pressure of IIH patients was measured by manometry. Results CSF-NfL levels (r = 0.29, p = 0.008) and QNfL (0.40, p = 0.0009), but not serum NfL (S-NfL) levels, were associated with lumbar puncture opening pressure in IIH patients. CSF-NfL levels were increased in IIH patients, MS patients, and PNP patients, whereas sNfL levels were normal in IIH, but elevated in MS and PNP. Remarkably, QNfL (p

Immunomodulatory and immunosuppressive therapy is needed in people with a chronic neuroinflammatory disease of the central nervous system such as multiple sclerosis (MS). Therefore, MS requires monitoring for and preventing against infectious diseases like SARS-CoV-2. Vaccination and anti-viral treatments are, in particular, recommended for elderly people and people at risk of a severe course of infection and of MS. Here, we asked whether repetitive infection or vaccination influenced responses upon receiving high efficacy treatments, namely sphingosine-1-phosphate receptor modulator (S1P) or anti-CD20 B cell antibody (anti-CD20) treatments. We performed a prospective real-world study of people with MS (pwMS) under S1P or anti-CD20 with repetitive exposure to the SARS-CoV-2 virus or vaccine. The measurement of anti-SARS-CoV-2 antibody titres was performed by two independent immunoassays after initial immunisation and after booster vaccination or infection. Other laboratory and clinical parameters were included in the analysis of influencing factors. As secondary outcomes, lymphocyte and immunoglobulin levels were observed longitudinally under intravenous and subcutaneous anti-CD20 treatment. In a long-term real-world cohort of 201 pwMS, we found that despite lymphopenia upon S1P drugs, the SARS-CoV-2 immunisation response increased both in selective and non-selective S1P (100% and 88% seroconversion, respectively), whereas those under anti-CD20 therapies merely exhibited a slight long-term increase in antibody titres (52% seroconversion). The latter was independent of immunoglobulin or total lymphocyte levels, which mostly remained stable. If the individual was immunised prior to therapy initiation, their levels of SARS-CoV-2 antibodies remained high under treatment. PwMS under non-selective S1P benefit from repetitive vaccination. The risk of an insufficient vaccination response mirrored by lower SARS-CoV-2 antibodies remains in pwMS receiving anti-CD20 treatment, even after repetitive exposure to the vaccine or virus. Due to the compromised vaccination response in CD20-depleting drugs, prompt antiviral treatment might be necessary.

Background: Depression has a major impact on the disease burden of multiple sclerosis (MS). Analyses of overlapping MS and depression risk factors [smoking, vitamin D (25-OH-VD) and Epstein-Barr virus (EBV) infection] and sex, age, disease characteristics and neuroimaging features associated with depressive symptoms in early MS are scarce. Objectives: To assess an association of MS risk factors with depressive symptoms within the German NationMS cohort. Design: Cross-sectional analysis within a multicenter observational study. Methods: Baseline data of n = 781 adults with newly diagnosed clinically isolated syndrome or relapsing-remitting MS qualified for analysis. Global and region-specific magnetic resonance imaging (MRI)-volumetry parameters were available for n = 327 patients. Association of demographic factors, MS characteristics and risk factors [sex, age, smoking, disease course, presence of current relapse, expanded disability status scale (EDSS) score, fatigue (fatigue scale motor cognition), 25-OH-VD serum concentration, EBV nuclear antigen-1 IgG (EBNA1-IgG) serum levels] and depressive symptoms (Beck Depression Inventory-II, BDI-II) was tested as a primary outcome by multivariable linear regression. Non-parametric correlation and group comparison were performed for associations of MRI parameters and depressive symptoms. Results: Mean age was 34.3 years (95% confidence interval: 33.6–35.0). The female-to-male ratio was 2.3:1. At least minimal depressive symptoms (BDI-II > 8) were present in n = 256 (32.8%), 25-OH-VD deficiency (

Abstract Objective Intravenous methylprednisolone is the standard treatment for a multiple sclerosis relapse; however, this fails to improve symptoms in up to one quarter of patients. Immunoadsorption is an accepted treatment for refractory relapses, but prospective comparator-controlled studies are missing. Methods In this observational study, patients with steroid-refractory acute multiple sclerosis relapses receiving either six courses of tryptophan-immunoadsorption or double-dose methylprednisolone therapy were analysed. Outcomes were evaluated at discharge and three months later. Immune profiling of blood lymphocytes and proteomic analysis were performed by multi-parameter flow cytometry and Olink analysis, respectively (NCT04450030). Results 42 patients were enrolled (methylprednisolone: 26 patients; immunoadsorption: 16 patients). For determination of the primary outcome, treatment response was stratified according to relative function system score changes (“full/best” vs. “average” vs. “worse/none”). Upon discharge, the adjusted odds ratio for any treatment response (“full/best” + ”average” vs. “worse/none”) was 10.697 favouring immunoadsorption (p = 0.005 compared to methylprednisolone). At follow-up, the adjusted odds ratio for the best treatment response (“full/best” vs. “average” + ”worse/none”) was 103.236 favouring IA patients (p = 0.001 compared to methylprednisolone). Similar results were observed regarding evoked potentials and quality of life outcomes, as well as serum neurofilament light-chain levels. Flow cytometry revealed a profound reduction of B cell subsets following immunoadsorption, which was closely correlated to clinical outcomes, whereas methylprednisolone had a minimal effect on B cell populations. Immunoadsorption treatment skewed the blood cytokine network, reduced levels of B cell-related cytokines and reduced immunoglobulin levels as well as levels of certain coagulation factors. Interpretation Immunoadsorption demonstrated favourable outcomes compared to double-dose methylprednisolone. Outcome differences were significant at discharge and follow-up. Further analyses identified modulation of B cell function as a potential mechanism of action for immunoadsorption, as reduction of B cell subsets correlated with clinical improvement.

Background: Western lifestyle has been associated with an increase in relapsing–remitting multiple sclerosis (RRMS). In mice, dietary wheat amylase–trypsin inhibitors (ATIs) activate intestinal myeloid cells and augment T cell-mediated systemic inflammation. Objective: The aim of this study was to assess whether a wheat- and thus ATI-reduced diet might exert beneficial effects in RRMS patients with modest disease activity. Methods: In this 6-month, crossover, open-label, bicentric proof-of-concept trial, 16 RRMS patients with stable disease course were randomized to either 3 months of a standard wheat-containing diet with consecutive switch to a > 90% wheat-reduced diet, or vice versa. Results: The primary endpoint was negative, as the frequency of circulating pro-inflammatory T cells did not decrease during the ATI-reduced diet. We did, however, observe decreased frequencies of CD14 + CD16 ++ monocytes and a concomitant increase in CD14 ++ CD16 − monocytes during the wheat-reduced diet interval. This was accompanied by an improvement in pain-related quality of life in health-related quality of life assessed (SF-36). Conclusion: Our results suggest that the wheat- and thus ATI-reduced diet was associated with changes in monocyte subsets and improved pain-related quality of life in RRMS patients. Thus, a wheat (ATI)-reduced diet might be a complementary approach accompanying immunotherapy for some patients. Registration: German Clinical Trial Register (No. DRKS00027967).

Background & Aims: Blood biomarkers facilitating the diagnosis of covert hepatic encephalopathy (CHE) in patients with cirrhosis are lacking. Astrocyte swelling is a major component of hepatic encephalopathy. Thus, we hypothesised that glial fibrillary acidic protein (GFAP), the major intermediate filament of astrocytes, might facilitate early diagnosis and management. This study aimed to investigate the utility of serum GFAP (sGFAP) levels as a biomarker of CHE. Methods: In this bicentric study, 135 patients with cirrhosis, 21 patients with ongoing harmful alcohol use and cirrhosis, and 15 healthy controls were recruited. CHE was diagnosed using psychometric hepatic encephalopathy score. sGFAP levels were measured using a highly sensitive single-molecule array (SiMoA) immunoassay. Results: In total, 50 (37%) people presented with CHE at study inclusion. Participants with CHE displayed significantly higher sGFAP levels than those without CHE (median sGFAP, 163 pg/ml [IQR 136; 268] vs. 106 pg/ml [IQR 75; 153]; p

Abstract Background Anxiety, often seen as comorbidity in multiple sclerosis (MS), is a frequent neuropsychiatric symptom and essentially affects the overall disease burden. Here, we aimed to decipher anxiety-related networks functionally connected to atrophied areas in patients suffering from MS. Methods Using 3-T MRI, anxiety-related atrophy maps were generated by correlating longitudinal cortical thinning with the severity of anxiety symptoms in MS patients. To determine brain regions functionally connected to these maps, we applied a technique termed “atrophy network mapping”. Thereby, the anxiety-related atrophy maps were projected onto a large normative connectome (n = 1000) performing seed‐based functional connectivity. Finally, an instructed threat paradigm was conducted with regard to neural excitability and effective connectivity, using transcranial magnetic stimulation combined with high-density electroencephalography. Results Thinning of the left dorsal prefrontal cortex was the only region that was associated with higher anxiety levels. Atrophy network mapping identified functional involvement of bilateral prefrontal cortex as well as amygdala and hippocampus. Structural equation modeling confirmed that the volumes of these brain regions were significant determinants that influence anxiety symptoms in MS. We additionally identified reduced information flow between the prefrontal cortex and the amygdala at rest, and pathologically increased excitability in the prefrontal cortex in MS patients as compared to controls. Conclusion Anxiety-related prefrontal cortical atrophy in MS leads to a specific network alteration involving structures that resemble known neurobiological anxiety circuits. These findings elucidate the emergence of anxiety as part of the disease pathology and might ultimately enable targeted treatment approaches modulating brain networks in MS.

Summary: Background: Disease-modifying therapies (DMT) for multiple sclerosis (MS) influence SARS-CoV-2 vaccination response, which might have implications for vaccination regimens in individual patients. Expanding the knowledge of predictors for an insufficient vaccination response as a surrogate for protection against severe disease courses of infection in people with MS (pwMS) under DMT is of great importance in identifying high-risk populations. Methods: Cross-sectional analysis of vaccination titre and its modifiers, in a prospective real-world cohort of 386 individuals (285 pwMS and 101 healthy controls) by two independent immunoassays between October 2021 and June 2022. Findings: In our cohort, no difference in vaccination antibody level was evident between healthy controls (HC) and untreated pwMS. In pwMS lymphocyte levels, times vaccinated and DMT influence SARS-CoV-2 titre following vaccination. Those treated with selective sphingosine-1-phosphate receptor modulators (S1P) showed comparable vaccination titres to untreated; higher CD8 T cell levels prior to vaccination in B cell-depleted patients resulted in increased anti-spike SARS-CoV2 antibody levels. Interpretation: PwMS under DMT with anti-CD20 treatment, in particular those with decreased CD8 levels before vaccination, as well as non-selective S1P but not selective S1P are at increased risk for insufficient SARS-CoV-2 vaccination response. This argues for a close monitoring of anti-spike antibodies in order to customize individual vaccination regimens within these patients. Funding: This work was supported by the German Research Foundation (DFG, CRC-TR-128 to TU, SB, and FZ).

Background & Aims: The 2-pore potassium channel subfamily K member 9 (KCNK9) regulates intracellular calcium concentration and thus modulates cell survival and inflammatory signaling pathways. It also was recognized as a risk allele for inflammatory bowel disease. However, it remains unclear whether KCNK9 modulates inflammatory bowel disease via its impact on immune cell function or whether its influence on calcium homeostasis also is relevant in intestinal epithelial cells. Methods: Kcnk9-/- mice were challenged with 3% dextran sulfate sodium (DSS) to induce experimental acute colitis. Primary cultures of intestinal epithelial cells were generated, and expression of potassium channels as well as cytosolic calcium levels and susceptibility to apoptosis were evaluated. Furthermore, we evaluated whether KCNK9 deficiency was compensated by the closely related 2-pore potassium channel KCNK3 in vivo or in vitro. Results: Compared with controls, KCNK9 deficiency or its pharmacologic blockade were associated with aggravated DSS-induced colitis compared with wild-type animals. In the absence of KCNK9, intestinal epithelial cells showed increased intracellular calcium levels and were more prone to mitochondrial damage and caspase-9–dependent apoptosis. We found that expression of KCNK3 was increased in Kcnk9-/- mice but did not prevent apoptosis after DSS exposure. Conversely, increased levels of KCNK9 in Kcnk3-/- mice were associated with an ameliorated course of DSS-induced colitis. Conclusions: KCNK9 enhances mitochondrial stability, reduces apoptosis, und thus supports epithelial cell survival after DSS exposure in vivo and in vitro. Conversely, its increased expression in Kcnk3-/- resulted in less mitochondrial damage and apoptosis and was associated with beneficial outcomes in DSS-induced colitis.

Lasers can exhibit nonlinear and chaotic dynamics driven by the interaction of multiple lasing modes, and investigating the different scenarios of mode competition and bifurcations of their dynamics is of great interest on a fundamental level as well as in view of applications. We study the dynamics of a broad-area vertical-cavity surface-emitting laser (VCSEL) in solitary continuous-wave operation with a comprehensive investigation of its polarization state, lasing spectra, near-field distributions, and temporal dynamics. Fluctuations at the frequency of birefringence splitting and other frequency components develop in a series of bifurcations. The bifurcations coincide with changes of the transverse lasing modes and/or the polarization state, demonstrating the importance of both the spatial and polarization degrees of freedom for mode competition. As a consequence, the inherent nonlinear dynamics of broad-area VCSELs is significantly more complex than the dynamics of VCSELs with a single spatial mode.

Background: For treatment of relapsing-remitting multiple sclerosis (RRMS), a broad range of disease-modifying therapies (DMT) is available. However, few comparative effectiveness studies between different drugs have been performed. Objectives: This study aimed to compare the efficacy and treatment continuation of natalizumab and ocrelizumab in a real-world cohort of patients with relapsing-remitting multiple sclerosis (RRMS) from two German university hospitals. Methods: We performed a retrospective analysis of RRMS patients who initiated treatment with natalizumab or ocrelizumab between January 2016 and April 2019 at the German university hospitals of Mainz and Düsseldorf. Bayesian propensity score matching was conducted to correct for differences in baseline characteristics. Our primary outcome was no evidence of disease activity [NEDA-3: no relapses, no confirmed disability progression, and no magnetic resonance imaging (MRI) activity] and its subcomponents. Secondary outcomes included measurement of neurofilament light chain (NfL) in serum, analysis of premature discontinuation, and evidence of rebound activity in patients switching from natalizumab to ocrelizumab. Results: We identified 63 patients starting treatment with natalizumab and 76 patients starting with ocrelizumab. Binary logistic regression showed that treatment with natalizumab or a higher number of relapses in the previous year were independently associated with a higher risk for relapses. Patients receiving natalizumab had a higher probability of premature discontinuation of therapy ( p = 0.002). After propensity score matching of the two treatment arms, 55 patients remained per group. NEDA-3 after 30 months of follow-up was reached by 53.1% in the ocrelizumab group and 36.1% in the natalizumab group ( p = 0.177). Ocrelizumab was superior to natalizumab concerning the occurrence of relapses in log-rank test ( p = 0.019). NfL levels in serum were low under both treatments. Patients who switched from natalizumab to ocrelizumab showed no increased rebound activity. Discussion: This study provides class IV evidence that treatment of RRMS patients with ocrelizumab and natalizumab show comparable effectiveness in combined endpoints, while ocrelizumab might be more effective in preventing the occurrence of relapses.

Neuroinflammation after stroke is characterized by the activation of resident microglia and the invasion of circulating leukocytes into the brain. Although lymphocytes infiltrate the brain in small number, they have been consistently demonstrated to be the most potent leukocyte subpopulation contributing to secondary inflammatory brain injury. However, the exact mechanism of how this minimal number of lymphocytes can profoundly affect stroke outcome is still largely elusive. Here, using a mouse model for ischemic stroke, we demonstrated that early activation of microglia in response to stroke is differentially regulated by distinct T cell subpopulations – with TH1 cells inducing a type I INF signaling in microglia and regulatory T cells (TREG) cells promoting microglial genes associated with chemotaxis. Acute treatment with engineered T cells overexpressing IL-10 administered into the cisterna magna after stroke induces a switch of microglial gene expression to a profile associated with pro-regenerative functions. Whereas microglia polarization by T cell subsets did not affect the acute development of the infarct volume, these findings substantiate the role of T cells in stroke by polarizing the microglial phenotype. Targeting T cell-microglia interactions can have direct translational relevance for further development of immune-targeted therapies for stroke and other neuroinflammatory conditions.

In primary murine hippocampal neurons we investigated the regulation of EAAT3-mediated glutamate transport by the Clostridium botulinum C3 transferase C3bot and a 26mer peptide derived from full length protein. Incubation with either enzyme-competent C3bot or enzyme-deficient C3bot156–181 peptide resulted in the upregulation of glutamate uptake by up to 22% compared to untreated cells. A similar enhancement of glutamate transport was also achieved by the classical phorbol-ester-mediated activation of protein kinase C subtypes. Yet comparable, effects elicited by C3 preparations seemed not to rely on PKCα, γ, ε, or ζ activation. Blocking of tyrosine phosphorylation by tyrosine kinase inhibitors prevented the observed effect mediated by C3bot and C3bot 26mer. By using biochemical and molecular biological assays we could rule out that the observed C3bot and C3bot 26mer-mediated effects solely resulted from enhanced transporter expression or translocation to the neuronal surface but was rather mediated by transporter phosphorylation at tyrosine residues that was found to be significantly enhanced following incubation with either full length protein or the 26mer C3 peptide.

The ray dynamics of optical cavities exhibits bifurcation points: special geometries at which ray trajectories switch abruptly between stable and unstable. A prominent example is the Fabry–Perot cavity with two planar mirrors, which is widely employed for broad-area semiconductor lasers. Such cavities support lasing in a relatively small number of transverse modes, and the laser is highly susceptible to filamentation and irregular pulsations. Here, we demonstrate experimentally that a slight deviation from this bifurcation point (planar cavity) dramatically changes the laser performance. In a near-planar cavity with two concave mirrors, the number of transverse lasing modes increases drastically. While the spatial coherence of the laser emission is reduced, the divergence angle of the output beam remains relatively narrow. Moreover, the spatiotemporal lasing dynamics becomes significantly more stable compared to that in a Fabry–Perot cavity. Our near-planar broad-area semiconductor laser has higher brightness, better directionality, and hence allows shorter integration times than an incandescent lamp while featuring sufficiently low speckle contrast at the same time, making it a vastly superior light source for speckle-free imaging. Furthermore, our method of controlling spatiotemporal dynamics with extreme sensitivity near a bifurcation point may be applied to other types of high-power lasers and nonlinear dynamic systems.

Abstract Background T helper (Th) 17 cells are a highly plastic subset of T cells, which in the context of neuroinflammation, are able to acquire pathogenic features originally attributed to Th1 cells (resulting in so called ex-Th17 cells). Thus, a strict separation between the two T cell subsets in the context of experimental autoimmune encephalomyelitis (EAE) is difficult. High variability in culture and EAE induction protocols contributed to previous conflicting results concerning the differential contribution of Th1 and Th17 cells in EAE. Here, we systematically evaluate the role of different T cell differentiation and transfer protocols for EAE disease development and investigate the functional dynamics of encephalitogenic T cells directly within the inflamed central nervous system (CNS) tissue. Methods We compiled the currently used EAE induction protocols reported in literature and investigated the influence of the different Th1 and Th17 differentiation protocols as well as EAE induction protocols on the EAE disease course. Moreover, we assessed the cytokine profile and functional dynamics of both encephalitogenic Th1 and Th17 cells in the inflamed CNS using flow cytometry and intravital two-photon laser scanning microscopy. Lastly, we used astrocyte culture and adoptive transfer EAE to evaluate the impact of Th1 and Th17 cells on astrocyte adhesion molecule expression in vitro and in vivo. Results We show that EAE courses are highly dependent on in vitro differentiation and transfer protocols. Moreover, using genetically encoded reporter mice (B6.IL17A-EGFP.acRFP x 2d2/2d2.RFP), we show that the motility of interferon (IFN)γ-producing ex-Th17 cells more closely resembles Th1 cells than Th17 cells in transfer EAE. Mechanistically, IFNγ-producing Th1 cells selectively induce the expression of cellular adhesion molecules I-CAM1 while Th1 as well as ex-Th17 induce V-CAM1 on astrocytes. Conclusions The behavior of ex-Th17 cells in EAE lesions in vivo resembles Th1 rather than Th17 cells, underlining that their change in cytokine production is associated with functional phenotype alterations of these cells.

Abstract Beyond the major role of T cells in the pathogenesis of the autoimmune neuroinflammatory disorder multiple sclerosis (MS), recent studies have highlighted the impact of B cells on pathogenic inflammatory processes. Follicular T helper cells (Tfh) are essential for the promotion of B cell-driven immune responses. However, their role in MS and its murine model, experimental autoimmune encephalomyelitis (EAE), is poorly investigated. A first step to achieving a better understanding of the contribution of Tfh cells to the disease is the consideration of Tfh cell localization in relation to genetic background and EAE induction method. Here, we investigated the Tfh cell distribution during disease progression in disease relevant organs in three different EAE models. An increase of Tfh frequency in the central nervous system (CNS) was observed during peak of C57BL/6 J EAE, paralleling chronic disease activity, whereas in relapsing–remitting SJL EAE mice Tfh cell frequencies were increased during remission. Furthermore, transferred Tfh-skewed cells polarized in vitro induced mild clinical symptoms in B6.Rag1−/− mice. We identified significantly higher levels of Tfh cells in the dura mater than in the CNS both in C57BL/6 and in SJL/J mice. Overall, our study emphasizes diverse, non-static roles of Tfh cells during autoimmune neuroinflammation.

Dimethyl fumarate (DMF) is a therapy for multiple sclerosis (MS) with undetermined mechanism of action. Here the authors find that clinical response to DMF associates with decrease in IL-17-producing CD8+ T cells (Tc17), delineate molecular pathways involved, and show that DMF suppresses Tc17 pathogenicity in a mouse model of MS.

Background Patients with multiple sclerosis (MS) receiving immunomodulatory drugs were excluded from clinical trials on COVID-19 vaccines. Therefore, data regarding the efficacy of COVID-19 vaccines to induce humoral immunity in MS patients treated with B- and T-cell depleting agents is urgently warranted. Cladribine tablets are a high-efficacy disease-modifying treatment that exerts its therapeutic effect via sustained but transient lymphocyte depletion. Aim We report humoral responses in a German cohort of MS patients treated with cladribine tablets. Methods This retrospective analysis included patients ≥18 years who were treated with cladribine tablets for relapsing MS in the first or second year and were fully vaccinated against COVID-19. Two weeks after the second vaccination at the earliest, blood samples were obtained for the assessment of anti-SARS-CoV-2 IgG antibodies, lymphocyte counts, B-cells, CD4 + T-cells, and CD8 + T-cells. Anti-SARS-CoV-2 IgG antibodies were quantified with the LIAISON ® SARS-CoV-2 TrimericS IgG assay. Positivity was defined at a cutoff value of 33.8 BAU/mL. Results In total, 38 patients (73.7% female, aged 23–66 years) were included in the analysis. Ten patients (26.3%) were treatment-naïve before initiating treatment with cladribine tablets. Most patients (84.2%) received mRNA vaccines. The time between the last dose of cladribine tablets and vaccination ranged between 2 and 96 weeks. Six patients (15.8%) were vaccinated within 4 weeks of their last cladribine dose. All patients achieved positive anti-SARS-CoV-2 IgG antibody levels. Humoral immune response was independent of age, time of vaccination in relation to the last cladribine dose, lymphocyte counts as well as B- and T-cell counts. Conclusions Treatment with cladribine tablets did not impair humoral response to COVID-19 vaccination. Time since last cladribine dose, age, prior therapy, lymphocyte count as well as B- and T-cell counts had no effect on seropositivity of anti-SARS-CoV-2 IgG antibodies.

Motor skills are frequently impaired in multiple sclerosis (MS) patients following grey and white matter damage with cortical excitability abnormalities. We applied advanced diffusion imaging with 3T magnetic resonance tomography for neurite orientation dispersion and density imaging (NODDI), as well as diffusion tensor imaging (DTI) in 50 MS patients and 49 age-matched healthy controls to quantify microstructural integrity of the motor system. To assess excitability, we determined resting motor thresholds using non-invasive transcranial magnetic stimulation. As measures of cognitive-motor performance, we conducted neuropsychological assessments including the Nine-Hole Peg Test, Trail Making Test part A and B (TMT-A and TMT-B) and the Symbol Digit Modalities Test (SDMT). Patients were evaluated clinically including assessments with the Expanded Disability Status Scale. A hierarchical regression model revealed that lower neurite density index (NDI) in primary motor cortex, suggestive for axonal loss in the grey matter, predicted higher motor thresholds, i.e. reduced excitability in MS patients (p = .009, adjusted r² = 0.117). Furthermore, lower NDI was indicative of decreased cognitive-motor performance (p = .007, adjusted r² = .142 for TMT-A; p = .009, adjusted r² = .129 for TMT-B; p = .006, adjusted r² = .142 for SDMT). Motor WM tracts of patients were characterized by overlapping clusters of lowered NDI (p

Background: The aim was to evaluate the diagnostic potential of serum neurofilament light chain (sNfL) measurements in patients with neuropsychiatric systemic lupus erythematosus (NPSLE). Methods: sNfL levels were determined by single molecule array assay in a retrospective cross-sectional cohort of 144 patients with systemic lupus erythematosus (SLE). After log-transformation of sNfL levels, mean sNfL levels were compared between NPSLE patients and SLE patients without neuropsychiatric disease using Student’s t test. Furthermore, the association of different neuropsychiatric manifestations with sNfL levels was assessed using a one-way analysis of variance (ANOVA) with post hoc analysis. Associations of sNfL with clinical and laboratory parameters were assessed by correlation and multiple linear regression analysis. Results: NPSLE patients ( n = 69) had significantly higher sNfL levels than SLE patients without neuropsychiatric disease manifestations ( n = 75; mean difference: 0.13, 95% CI: 0.04–0.22, p = 0.006). With regard to the category of NPSLE manifestation, mean sNfL levels were only increased in NPSLE patients with focal central nervous system (CNS) involvement ( n = 45; mean difference: 0.16, 95% CI: 0.02–0.30, p = 0.019), whereas mean sNfL levels of NPSLE patients with diffuse CNS and peripheral nervous system involvement did not differ from those of SLE patients without neuropsychiatric manifestations. Age and serum creatinine concentrations were identified as relevant contributors to sNfL levels. Conclusion: sNfL is a promising, easily accessible biomarker for neuropsychiatric involvement in SLE patients and might therefore complement the diagnostic workup of SLE patients with suspected involvement of the nervous system.

Background: Easily accessible biomarkers enabling the identification of those patients with multiple sclerosis (MS) who will accumulate irreversible disability in the long term are essential to guide early therapeutic decisions. We here examine the utility of serum neurofilament light chain (sNfL) for forecasting relapse-free disability progression and conversion to secondary progressive MS (SPMS) in the prospective Neurofilament and longterm outcome in MS (NaloMS) cohort. Methods: The predictive ability of sNfL at Baseline and sNfL follow-up (FU)/ Baseline (BL) ratio with regard to disability progression was assessed within a development cohort (NaloMS, n=196 patients with relapsing-remitting MS (RRMS) or clinically isolated syndrome) and validated with an external independent cohort (Düsseldorf, Essen, n=204). Both relapse-free EDSS-progression (RFP: inflammatory-independent EDSS-increase 12 months prior to FU) and SPMS-transition (minimum EDSS-score of 3.0) were investigated. Findings: During the study period, 17% (n=34) of NaloMS patients suffered from RFP and 14% (n=27) converted to SPMS at FU (validation cohort RFP n=42, SPMS-conversion n=24). sNfL at BL was increased in patients with RFP (10.8 pg/ml (interquartile range (IQR) 7.7-15.0) vs. 7.2 pg/ml (4.5-12.5), p

Multiple sclerosis is a complex, autoimmune-mediated disease of the central nervous system characterized by inflammatory demyelination and axonal/neuronal damage. The approval of various disease-modifying therapies and our increased understanding of disease mechanisms and evolution in recent years have significantly changed the prognosis and course of the disease. This update of the Multiple Sclerosis Therapy Consensus Group treatment recommendation focuses on the most important recommendations for disease-modifying therapies of multiple sclerosis in 2021. Our recommendations are based on current scientific evidence and apply to those medications approved in wide parts of Europe, particularly German-speaking countries (Germany, Austria, and Switzerland).

The past decades have yielded major therapeutic advances in many autoimmune conditions – such as multiple sclerosis (MS) – and thus ushered in a new era of more targeted and increasingly potent immunotherapies. Yet this growing arsenal of therapeutic immune interventions has also rendered therapy much more challenging for the attending physician, especially when treating patients with more than one autoimmune condition. Importantly, some therapeutic strategies are either approved for several autoimmune disorders or may be repurposed for other conditions, therefore opening new curative possibilities in related fields. In this article, we especially focus on frequent and therapeutically relevant concomitant autoimmune conditions faced by neurologists when treating patients with MS, namely psoriasis, rheumatoid arthritis and inflammatory bowel diseases. We provide an overview of the available disease-modifying therapies, highlight possible contraindications, show pathophysiological overlaps and finally present which therapeutics can be utilized as a combinatory treatment, in order to ‘kill two birds with one stone’.

Progressive multifocal leukoencephalopathy (PML) is a potentially fatal condition caused by a brain infection with JC polyomavirus (JCV), which occurs almost exclusively in immunocompromised patients. Modern immunosuppressive and immunomodulatory treatments for cancers and autoimmune diseases have been accompanied by increasing numbers of PML cases. We report a psoriasis patient treated with fumaric acid esters (FAEs) with concomitant hypopharyngeal carcinoma and chronic alcohol abuse who developed PML. Grade 4 lymphopenia at the time point of PML diagnosis suggested an immunocompromised state. This case underscores the importance of immune cell monitoring in patients treated with FAEs, even more so in the presence of additional risk factors for an immune dysfunction.

Background: Serum neurofilament light chain (sNfL) and distinct intra-retinal layers are both promising biomarkers of neuro-axonal injury in multiple sclerosis (MS). We aimed to unravel the association of both markers in early MS, having identified that neurofilament has a distinct immunohistochemical expression pattern among intra-retinal layers. Methods: Three-dimensional (3D) spectral domain macular optical coherence tomography scans and sNfL levels were investigated in 156 early MS patients (female/male: 109/47, mean age: 33.3 ± 9.5 years, mean disease duration: 2.0 ± 3.3 years). Out of the whole cohort, 110 patients had no history of optic neuritis (NHON) and 46 patients had a previous history of optic neuritis (HON). In addition, a subgroup of patients ( n = 38) was studied longitudinally over 2 years. Support vector machine analysis was applied to test a regression model for significant changes. Results: In our cohort, HON patients had a thinner outer plexiform layer (OPL) volume compared to NHON patients ( B = −0.016, SE = 0.006, p = 0.013). Higher sNfL levels were significantly associated with thinner OPL volumes in HON patients ( B = −6.734, SE = 2.514, p = 0.011). This finding was corroborated in the longitudinal subanalysis by the association of higher sNfL levels with OPL atrophy ( B = 5.974, SE = 2.420, p = 0.019). sNfL levels were 75.7% accurate at predicting OPL volume in the supervised machine learning. Conclusions: In summary, sNfL levels were a good predictor of future outer retinal thinning in MS. Changes within the neurofilament-rich OPL could be considered as an additional retinal marker linked to MS neurodegeneration.

Background: Serum neurofilament light chain (sNfL) is a promising biomarker to complement the decision-making process in multiple sclerosis (MS) patients. However, although sNfL levels are able to detect disease activity and to predict future disability, the growing evidence has not yet been translated into practicable recommendations for an implementation into clinical routine. Methods: The observation of a patient with extensive inflammatory activity in magnetic resonance imaging (MRI) along with an extremely high sNfL level in the absence of any clinical symptoms prompted us to investigate common characteristics of our MS patients with the highest sNfL levels in a retrospective cohort study. The 97.5th percentile was chosen as a cut-off value because the mean sNfL level of the resulting extreme neurofilament light chain (NfL) cohort corresponded well to the sNfL level of the presented case. Patient characterization included clinical and MRI assessment with a focus on disease activity markers. sNfL levels were determined by single molecule array. Results: The 97.5th percentile of our MS cohort (958 sNfL measurements in 455 patients) corresponded to a threshold value of 46.1 pg/ml. The mean sNfL level of the extreme sNfL cohort ( n = 24) was 95.6 pg/ml (standard deviation 68.4). Interestingly, only 15 patients suffered from a relapse at the time point of sample collection, whereas nine patients showed no signs of clinical disease activity. sNfL levels of patients with and without relapse did not differ [median 81.3 pg/ml (interquartile range [IQR] 48.0–128) versus 80.2 pg/ml (IQR 46.4–97.6), p = 0.815]. The proportion of patients with contrast-enhancing lesions was high and also did not differ between patients with and without relapse (92.9% versus 87.5%, p = 0.538); 78.9% of the patients not receiving a high-efficacious therapy had ongoing disease activity during a 2-year follow-up. Conclusion: Extremely high sNfL levels are indicative of subclinical disease activity and might complement treatment decisions in ambiguous cases.

Background/Aims: Multiple sclerosis (MS) is a prototypical autoimmune central nervous system (CNS) disease. Particularly progressive forms of MS (PMS) show significant neuroaxonal damage as consequence of demyelination and neuronal hyperexcitation. Immuno-modulatory treatment strategies are beneficial in relapsing MS (RMS), but mostly fail in PMS. Pregabalin (Lyrica®) is prescribed to MS patients to treat neuropathic pain. Mechanistically, it targets voltage-dependent Ca2+ channels and reduces harmful neuronal hyperexcitation in mouse epilepsy models. Studies suggest that GABA analogues like pregabalin exert neuroprotective effects in animal models of ischemia and trauma. Methods: We tested the impact of pregabalin in a mouse model of MS (experimental autoimmune encephalomyelitis, EAE) and performed histological and immunological evaluations as well as intravital two-photon-microscopy of brainstem EAE lesions. Results: Both prophylactic and therapeutic treatments ameliorated the clinical symptoms of EAE and reduced immune cell infiltration into the CNS. On neuronal level, pregabalin reduced long-term potentiation in hippocampal brain slices indicating an impact on mechanisms of learning and memory. In contrast, T cells, microglia and brain endothelial cells were unaffected by pregabalin. However, we found a direct impact of pregabalin on neurons during CNS inflammation as it reversed the pathological elevation of neuronal intracellular Ca2+ levels in EAE lesions. Conclusion: The presented data suggest that pregabalin primarily acts on neuronal Ca2+ channel trafficking thereby reducing Ca2+-mediated cytotoxicity and neuronal damage in an animal model of MS. Future clinical trials need to assess the benefit for neuronal survival by expanding the indication for pregabalin administration to MS patients in further disease phases.

Summary: Glia, the helper cells of the brain, are essential in maintaining neural resilience across time and varying challenges: By reacting to changes in neuronal health glia carefully balance repair or disposal of injured neurons. Malfunction of these interactions is implicated in many neurodegenerative diseases. We present a reductionist model that mimics repair-or-dispose decisions to generate a hypothesis for the cause of disease onset. The model assumes four tissue states: healthy and challenged tissue, primed tissue at risk of acute damage propagation, and chronic neurodegeneration. We discuss analogies to progression stages observed in the most common neurodegenerative conditions and to experimental observations of cellular signaling pathways of glia-neuron crosstalk. The model suggests that the onset of neurodegeneration can result as a compromise between two conflicting goals: short-term resilience to stressors versus long-term prevention of tissue damage.

Background: We aim to evaluate serum neurofilament light chain (sNfL), indicating neuroaxonal damage, as a biomarker at diagnosis in a large cohort of early multiple sclerosis (MS) patients. Methods: In a multicentre prospective longitudinal observational cohort, patients with newly diagnosed relapsing-remitting MS (RRMS) or clinically isolated syndrome (CIS) were recruited between August 2010 and November 2015 in 22 centers. Clinical parameters, MRI, and sNfL levels (measured by single molecule array) were assessed at baseline and up to four-year follow-up. Findings: Of 814 patients, 54.7% (445) were diagnosed with RRMS and 45.3% (369) with CIS when applying 2010 McDonald criteria (RRMS[2010] and CIS[2010]). After reclassification of CIS[2010] patients with existing CSF analysis, according to 2017 criteria, sNfL levels were lower in CIS[2017] than RRMS[2017] patients (9.1 pg/ml, IQR 6.2–13.7 pg/ml, n = 45; 10.8 pg/ml, IQR 7.4–20.1 pg/ml, n = 213; p = 0.036). sNfL levels correlated with number of T2 and Gd+ lesions at baseline and future clinical relapses. Patients receiving disease-modifying therapy (DMT) during the first four years had higher baseline sNfL levels than DMT-naïve patients (11.8 pg/ml, IQR 7.5-20.7 pg/ml, n = 726; 9.7 pg/ml, IQR 6.4–15.3 pg/ml, n = 88). Therapy escalation decisions within this period were reflected by longitudinal changes in sNfL levels. Interpretation: Assessment of sNfL increases diagnostic accuracy, is associated with disease course prognosis and may, particularly when measured longitudinally, facilitate therapeutic decisions. Funding: Supported the German Federal Ministry for Education and Research, the German Research Council, and Hertie-Stiftung.

Since their introduction in 1999, anti-tumour necrosis factor-α (anti-TNF-α) therapies have been suspected repeatedly to be associated with the occurrence of central nervous system (CNS) demyelinating disorders, including multiple sclerosis (MS). However, recent publications were restricted to descriptions of monophasic demyelinating events or cases of relapsing–remitting MS (RRMS). We here provide the first case report of primary progressive MS (PPMS) onset upon anti-TNF-α therapy as well as a literature review of previously published cases of anti-TNF-α therapy-associated MS onset. The 51-year old male patient was treated with adalimumab due to psoriasis arthritis. About 18 months after treatment initiation, he developed slowly progressing neurological deficits including gait impairment, paraesthesia of the lower limbs, strangury and visual impairment, which led to the discontinuation of adalimumab therapy. Magnetic resonance imaging of the brain and the spinal cord revealed multiple inflammatory lesions and cerebrospinal fluid examination showed slight pleocytosis and positive oligoclonal bands. Thus, PPMS was diagnosed according to the 2017 revision of the McDonald criteria. As PPMS often causes only subtle symptoms in the beginning and early treatment discontinuation of anti-TNF-α therapy seems essential to improve the patient’s outcome, we think that it is important to increase the awareness of slowly progressing neurological deficits as a potential adverse event of anti-TNF-α therapy among all clinicians involved in the initiation and monitoring of these drugs. In addition, the occurrence of both RRMS and progressive MS upon anti-TNF-α therapy might suggest a shared TNF-α-mediated pathophysiological mechanism in the evolution of all MS subtypes.

Background/Aims: Substance P (SP) is a neuropeptide, likely acting as a neurotransmitter in the pharyngeal mucosa enhancing the swallow and cough reflex. Pharyngeal Electrical Stimulation (PES) induces a temporary increase of salivary SP levels in healthy adults. Previous evidence suggests that post-stroke dysphagia is related to reduced SP levels. Here, we investigated the effects of PES on SP levels in severely dysphagic stroke patients and a possible link between increase of SP and treatment success. Methods: 23 tracheotomized stroke patients who could not be decannulated due to severe and persisting dysphagia according to endoscopic evaluation received PES for 10 minutes a day over three consecutive days in this prospective single-center study. If initial treatment failed, repetitive stimulation cycles were provided. Saliva samples were collected before and directly after each PES. Results: 61% of participants were decannulated after the first treatment cycle. Increase of SP levels post-stimulation was closely related to treatment success, i.e. decannulation with 79% of successfully treated patients showing increase of SP, whereas 89% of unsuccessfully treated patients had stable or decreased SP levels. Applying logistic regression analysis, increase of SP level remained the only independent predictor of decannulation after PES. All 3 repetitively treated patients showed increased SP levels when progressing from the 1st to the 2nd cycle, two of whom were decannulated hereafter. Conclusions: The physiological mechanism of PES may consist in restoration of sensory feedback, which is known to be crucial for the execution of a safe swallow. SP possibly acts as a biomarker for indicating response to PES.

Abstract Recombinant TWIK2 channels produce weak basal background K+ currents. Current amplitudes depend on the animal species the channels have been isolated from and on the heterologous system used for their re-expression. Here we show that this variability is due to a unique cellular trafficking. We identified three different sequence signals responsible for the preferential expression of TWIK2 in the Lamp1-positive lysosomal compartment. Sequential inactivation of tyrosine-based (Y308ASIP) and di-leucine-like (E266LILL and D282EDDQVDIL) trafficking motifs progressively abolishes the targeting of TWIK2 to lysosomes, and promotes its functional relocation at the plasma membrane. In addition, TWIK2 contains two N-glycosylation sites (N79AS and N85AS) on its luminal side, and glycosylation is necessary for expression in lysosomes. As shown by electrophysiology and electron microscopy, TWIK2 produces functional background K+ currents in the endolysosomes, and its expression affects the number and mean size of the lysosomes. These results show that TWIK2 is expressed in lysosomes, further expanding the registry of ion channels expressed in these organelles.

Background: Efficient personalized therapy paradigms are needed to modify the disease course and halt gray (GM) and white matter (WM) damage in patients with multiple sclerosis (MS). Presently, promising disease-modifying drugs show impressive efficiency, however, tailored markers of therapy responses are required. Here, we aimed to detect in a real-world setting patients with a more favorable brain network response and immune cell dynamics upon dimethyl fumarate (DMF) treatment.Methods: In a cohort of 78 MS patients we identified two thoroughly matched groups, based on age, disease duration, disability status and lesion volume, receiving DMF (n = 42) and NAT (n = 36) and followed them over 16 months. The rate of cortical atrophy and deep GM volumes were quantified. GM and WM network responses were characterized by brain modularization as a marker of regional and global structural alterations. In the DMF group, lymphocyte subsets were analyzed by flow cytometry and related to clinical and MRI parameters.Results: Sixty percent (25 patients) of the DMF and 36% (13 patients) of the NAT group had disease activity during the study period. The rate of cortical atrophy was higher in the DMF group (−2.4%) compared to NAT (−2.1%, p < 0.05) group. GM and WM network dynamics presented increased modularization in both groups. When dividing the DMF-treated cohort into patients free of disease activity (n = 17, DMFR) and patients with disease activity (n = 25, DMFNR) these groups differed significantly in CD8+ cell depletion counts (DMFR: 197.7 ± 97.1/μl; DMFNR: 298.4 ± 190.6/μl, p = 0.03) and also in cortical atrophy (DMFR: −1.7%; DMFNR: −3.2%, p = 0.01). DMFR presented reduced longitudinal GM and WM modularization and less atrophy as markers of preserved structural global network integrity in comparison to DMFNR and even NAT patients.Conclusions: NAT treatment contributes to a reduced rate of cortical atrophy compared to DMF therapy. However, patients under DMF treatment with a stronger CD8+ T cell depletion present a more favorable response in terms of cortical integrity and GM and WM network responses. Our findings may serve as basis for the development of personalized treatment paradigms.

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) leading to CNS inflammation and neurodegeneration. Current anti-inflammatory drugs have only limited efficacy on progressive neurodegenerative processes underlining the need to understand immune-mediated neuronal injury. Cell adhesion molecules play an important role for immune cell migration over the blood-brain barrier whereas their role in mediating potentially harmful contacts between invading immune cells and neurons is incompletely understood. Here, we assess the role of the CNS-specific neuronal adhesion molecule ICAM-5 using experimental autoimmune encephalomyelitis (EAE), an animal model of MS. ICAM-5 knockout mice show a more severe EAE disease course in the chronic phase indicating a neuroprotective function of ICAM-5 in progressive neurodegeneration. In agreement with the predominant CNS-specific function of ICAM-5, lymphocyte function-associated antigen 1 (LFA-1)/ICAM-1 contact between antigen-presenting cells and T helper (Th)17 cells in EAE is not affected by ICAM-5. Strikingly, intrathecal application of the shed soluble form, sICAM-5, ameliorates EAE disease symptoms and thus might serve locally as an endogenous neuronal defense mechanism which is activated upon neuroinflammation in the CNS. In humans, cerebrospinal fluid from patients suffering from progressive forms of MS shows decreased sICAM-5 levels, suggesting a lack of this endogenous protective pathway in these patient groups. Overall, our study points toward a novel role of ICAM-5 in CNS autoinflammation in progressive EAE/MS.

Factor XII initiates the intrinsic blood coagulation cascade and the kinin system. Here the authors show that Factor XII is elevated in the blood of multiple sclerosis patients, activates dendritic cells via CD87 and cAMP, and its blockade inhibits immunopathology in a mouse model of the disease.

Breakdown of the blood-brain barrier (BBB) is an early hallmark of multiple sclerosis (MS), a progressive inflammatory disease of the central nervous system. Cell adhesion in the BBB is modulated by sphingosine-1-phosphate (S1P), a signaling protein, via S1P receptors (S1P1). Fingolimod phosphate (FTY720-P) a functional S1P1 antagonist has been shown to improve the relapse rate in relapsing-remitting MS by preventing the egress of lymphocytes from lymph nodes. However, its role in modulating BBB permeability—in particular, on the tight junction proteins occludin, claudin 5 and ZO-1—has not been well elucidated to date. In the present study, FTY720-P did not change the transendothelial electrical resistance in a rat brain microvascular endothelial cell (RBMEC) culture exposed to inflammatory conditions and thus did not decrease endothelial barrier permeability. In contrast, occludin was reduced in RBMEC culture after adding FTY720-P. Additionally, FTY720-P did not alter the amount of endothelial matrix metalloproteinase (MMP)-9 and MMP-2 in RBMEC cultures. Taken together, our observations support the assumption that S1P1 plays a dual role in vascular permeability, depending on its ligand. Thus, S1P1 provides a mechanistic basis for FTY720-P-associated disruption of endothelial barriers—such as the blood-retinal barrier—which might result in macular edema.

We present experimental and numerical studies of broad-area semiconductor lasers with chaotic ray dynamics. The emission intensity distributions at the cavity boundaries are measured and compared to ray tracing simulations and numerical calculations of the passive cavity modes. We study two different cavity geometries, a D-cavity and a stadium, both of which feature fully chaotic ray dynamics. While the far-field distributions exhibit fairly homogeneous emission in all directions, the emission intensity distributions at the cavity boundary are highly inhomogeneous, reflecting the non-uniform intensity distributions inside the cavities. The excellent agreement between experiments and simulations demonstrates that the intensity distributions of wave-chaotic semiconductor lasers are primarily determined by the cavity geometry. This is in contrast to conventional Fabry–Perot broad-area lasers for which the intensity distributions are to a large degree determined by the nonlinear interaction of the lasing modes with the semiconductor gain medium.

Despite intense research, few treatments are available for most neurological disorders. Demyelinating diseases are no exception. This is perhaps not surprising considering the multifactorial nature of these diseases, which involve complex interactions between immune system cells, glia and neurons. In the case of multiple sclerosis, for example, there is no unanimity among researchers about the cause or even which system or cell type could be ground zero. This situation precludes the development and strategic application of mechanism-based therapies. We will discuss how computational modeling applied to questions at different biological levels can help link together disparate observations and decipher complex mechanisms whose solutions are not amenable to simple reductionism. By making testable predictions and revealing critical gaps in existing knowledge, such models can help direct research and will provide a rigorous framework in which to integrate new data as they are collected. Nowadays, there is no shortage of data; the challenge is to make sense of it all. In that respect, computational modeling is an invaluable tool that could, ultimately, transform how we understand, diagnose, and treat demyelinating diseases.

Lymphocytes express potassium channels that regulate physiological cell functions, such as activation, proliferation and migration. Expression levels of K2P5.1 (TASK2; KCNK5) channels belonging to the family of two-pore domain potassium channels have previously been correlated to the activity of autoreactive T lymphocytes in patients with multiple sclerosis and rheumatoid arthritis. In humans, K2P5.1 channels are upregulated upon T cell stimulation and influence T cell effector functions. However, a further clinical translation of targeting K2P5.1 is currently hampered by a lack of highly selective inhibitors, making it necessary to evaluate the impact of KCNK5 in established preclinical animal disease models. We here demonstrate that K2P5.1 knockout (K2P5.1−/−) mice display no significant alterations concerning T cell cytokine production, proliferation rates, surface marker molecules or signaling pathways. In an experimental model of autoimmune neuroinflammation, K2P5.1−/− mice show a comparable disease course to wild-type animals and no major changes in the peripheral immune system or CNS compartment. A compensatory upregulation of the potassium channels K2P3.1 and KV1.3 seems to counterbalance the deletion of K2P5.1. As an alternative model mimicking autoimmune neuroinflammation, experimental autoimmune encephalomyelitis in the common marmoset has been proposed, especially for testing the efficacy of new potential drugs. Initial experiments show that K2P5.1 is functionally expressed on marmoset T lymphocytes, opening up the possibility for assessing future K2P5.1-targeting drugs.

Alemtuzumab is a humanized monoclonal antibody against CD52 (cluster of differentiation 52) and is approved for the therapy of relapsing-remitting multiple sclerosis. The application of alemtuzumab leads to a rapid, but long-lasting depletion predominantly of CD52-bearing B and T cells with reprogramming effects on immune cell composition resulting in the restoration of tolerogenic networks. Alemtuzumab has proven high efficacy in clinical phase II and III trials, where interferon β-1a was used as active comparator. However, alemtuzumab is associated with frequent and considerable risks. Most importantly secondary autoimmune disease affects 30%–40% of patients, predominantly impairing thyroid function. Extensive monitoring and early intervention allow for an appropriate risk management. However, new and reliable biomarkers for individual risk stratification and treatment response to improve patient selection and therapy guidance are a significant unmet need. Only a deeper understanding of the underlying mechanisms of action (MOA) will reveal such markers, maximizing the best potential risk-benefit ratio for the individual patient. This review provides and analyses the current knowledge on the MOA of alemtuzumab. Most recent data on efficacy and safety of alemtuzumab are presented and future research opportunities are discussed.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease that is caused by an autoimmune response against central nervous system (CNS) structures. Traditionally considered a T-cell-mediated disorder, the contribution of B cells to the pathogenesis of MS has long been debated. Based on recent promising clinical results from CD20-depleting strategies by three therapeutic monoclonal antibodies in clinical phase II and III trials (rituximab, ocrelizumab and ofatumumab), targeting B cells in MS is currently attracting growing interest among basic researchers and clinicians. Many questions about the role of B and plasma cells in MS remain still unanswered, ranging from the role of specific B-cell subsets and functions to the optimal treatment regimen of B-cell depletion and monitoring thereafter. Here, we will assess our current knowledge of the mechanisms implicating B cells in multiple steps of disease pathology and examine current and future therapeutic approaches for the treatment of MS.