Myelin Oligodendrocyte Glycoprotein Antibodies in Adults with a First Demyelinating Event Suggestive of Multiple Sclerosis.

OBJECTIVE: Myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) distinguish multiple sclerosis (MS) from MOG-associated disease in most cases. However, studies analyzing MOG-Ab at the time of a first demyelinating event suggestive of MS in adults are lacking. We aimed to (1) evaluate the prevalence of MOG-Ab in a first demyelinating event suggestive of MS and (2) compare clinical and paraclinical features between seropositive (MOG-Ab+) and seronegative (MOG-Ab-) patients. METHODS: Six hundred thirty adult patients with available serum samples obtained within 6 months from the first event were included. MOG-Ab were analyzed using a live cell-based assay. Statistical analyses included parametric and nonparametric tests, logistic regression, and survival models. RESULTS: MOG-Ab were positive in 17 of 630 (2.7%). Fourteen out of 17 (82.4%) MOG-Ab+ patients presented with optic neuritis (ON) compared to 227of 613 (37.0%) MOG-Ab- patients (p = 0.009). Cerebrospinal fluid-restricted oligoclonal bands (CSF-OBs) were found in 2 of 16 (12.5%) MOG-Ab+ versus 371 of 601 (61.7%) MOG-Ab- subjects (p < 0.001). Baseline brain magnetic resonance imaging (MRI) was normal in 9 of 17 (52.9%) MOG-Ab+ versus 153 of 585 (26.2%) MOG-Ab- patients (p = 0.029). Absence of CSF-OBs and ON at onset were independently associated with MOG-Ab positivity (odds ratio [OR] = 9.03, 95% confidence interval [CI] = 2.04-53.6, p = 0.009; and OR = 4.17, 95% CI = 1.15-19.8, p = 0.042, respectively). Of MOG-Ab+ patients, 22.9% (95% CI = 0.0-42.7) compared to 67.6% (95% CI = 63.3-71.3) of MOG-Ab- patients fulfilled McDonald 2017 criteria at 5 years (log-rank p = 0.003). INTERPRETATION: MOG-Ab are infrequent in adults with a first demyelinating event suggestive of MS. However, based on our results, we suggest to determine these antibodies in those patients with ON and absence of CSF-OBs, as long as the brain MRI is not suggestive of MS. ANN NEUROL 2023.

Molecular signature associated with cladribine treatment in patients with multiple sclerosis.

Introduction: Little is known about the molecular profiling associated with the effect of cladribine in patients with multiple sclerosis (MS). Here, we aimed first to characterize the transcriptomic and proteomic profiles induced by cladribine in blood cells, and second to identify potential treatment response biomarkers to cladribine in patients with MS. Methods: Gene, protein and microRNA (miRNA) expression profiles were determined by microarrays (genes, miRNAs) and mass spectrometry (proteins) in peripheral blood mononuclear cells (PBMCs) from MS patients after in vitro treatment with cladribine in its active and inactive forms. Two bioinformatics approaches to integrate the three obtained datasets were applied: (i) a multiomics discriminant analysis (DIABLO - Data Integration Analysis for Biomarker discovery using Latent variable approaches for Omics studies); and (ii) a multi-stage integration of features selected in differential expression analysis on each dataset and then merged. Selected molecules from the in vitro study were quantified by qPCR ex vivo in PBMCs from MS patients receiving cladribine. Results: PBMCs treated in vitro with cladribine were characterized by a major downregulation of gene, protein, and miRNA expression compared with the untreated cells. An intermediate pattern between the cladribine-treated and untreated conditions was observed in PBMCs treated with cladribine in its inactive form. The differential expression analysis of each dataset led to the identification of four genes and their encoded proteins, and twenty-two miRNAs regulating their expression, that were associated with cladribine treatment. Two of these genes (PPIF and NHLRC2), and three miRNAs (miR-21-5p, miR-30b-5p, and miR-30e-5p) were validated ex vivo in MS patients treated with cladribine. Discussion: By using a combination of omics data and bioinformatics approaches we were able to identify a multiomics molecular profile induced by cladribine in vitro in PBMCs. We also identified a number of biomarkers that were validated ex vivo in PBMCs from patients with MS treated with cladribine that have the potential to become treatment response biomarkers to this drug.

Non-ADEM encephalitis in patients with myelin oligodendrocyte glycoprotein antibodies: a systematic review.

BACKGROUND AND PURPOSE: Non-(acute disseminated encephalomyelitis) (non-ADEM) encephalitis and/or fluid attenuated inversion recovery hyperintense lesions in anti-myelin-oligodendrocyte-glycoprotein-associated encephalitis with seizures (FLAMES) are rarely described in patients with myelin oligodendrocyte glycoprotein (MOG) antibodies (Abs). The aim was (i) to describe the clinical features and disease course of children and adults with non-ADEM encephalitis and/or FLAMES associated with MOG Abs and (ii) to describe their association with other central nervous system autoantibodies. METHODS: This was a systematic review following the PRISMA guidelines. Patients fulfilled criteria for non-ADEM encephalitis and/or FLAMES, and all were MOG Ab positive. RESULTS: In total, 83 (79%) patients with non-ADEM encephalitis (48 also had FLAMES) and 22 (21%) with isolated FLAMES were included. At the first episode, children (n = 45) had more infections (11/45, 24.4%; p = 0.017) and more of the phenotype consisting of non-ADEM encephalitis (42/45, 93.3%; p = 0.014) than adults (n = 38). Children had more episodes consistent with working memory deficits (25/54, 46.3%; p = 0.014) but fewer psychiatric symptoms (16/54, 29.6%; p = 0.002). Twenty-eight (40.6%) of 69 patients had N-methyl-d-aspartate receptor (NMDAR) Abs in cerebrospinal fluid (CSF), being more frequent in adults (19/29, 65.5%; p < 0.001). Compared to negatives, positive CSF NMDAR Abs had more relapses (14/20, 70%; p = 0.050), required ventilatory support more frequently (8/34, 23.5%; p = 0.009) and had more psychiatric episodes (28/34, 82%; p < 0.001) or abnormal movements (14/34, 41.2%; p = 0.008). Apart from an older age in FLAMES, positive and negative CSF NMDAR Ab groups shared similar features. CONCLUSION: Non-ADEM encephalitis patients with MOG Abs show specific clinical and radiological features, depending on the age at first episode. The presence of MOG Abs in non-ADEM encephalitis patients should not rule out to test other autoantibodies, especially concomitant NMDAR Abs in patients with suggestive symptoms such as behavioural or movement alterations.

Therapeutic Effect of IL-21 Blockage by Gene Therapy in Experimental Autoimmune Encephalomyelitis.

The pathogenic role of the interleukin 21 (IL-21) in different autoimmune diseases, such as multiple sclerosis (MS), has been extensively studied. However, its pleiotropic nature makes it a cytokine that may exhibit different activity depending on the immunological stage of the disease. In this study, we developed a gene therapy strategy to block the interaction between IL-21 and its receptor (IL-21R) by using adeno-associated vectors (AAV) encoding a new soluble cytokine receptor (sIL21R) protein. We tested this strategy in a murine model of experimental autoimmune encephalomyelitis (EAE), obtaining different clinical effects depending on the time at which the treatment was applied. Although the administration of the treatment during the development of the immune response was counterproductive, the preventive administration of the therapeutic vectors showed a protective effect by reducing the number of animals that developed the disease, as well as an improvement at the histopathological level and a modification of the immunological profile of the animals treated with the AAV8.sIL21R. The beneficial effect of the treatment was also observed when inducing the expression of the therapeutic molecule once the first neurological signs were established in a therapeutic approach with a doxycyline (Dox)-inducible expression system. All these clinical results highlight the pleiotropicity of this cytokine in the different clinical stages and its key role in the EAE immunopathogenesis.

The kappa free light chain index and oligoclonal bands have a similar role in the McDonald criteria.

Intrathecal production of kappa free light chains occurs in multiple sclerosis and can be measured using the kappa free light chain index. Kappa free light chain index values can be determined more easily than oligoclonal bands detection and seem more sensitive than the immunoglobulin (Ig)G index to diagnose multiple sclerosis. We assessed the value of oligoclonal bands, kappa free light chain index cut-offs 5.9, 6.6 and 10.61, and IgG index to diagnose multiple sclerosis with prospectively acquired data from a clinically isolated syndrome inception cohort. We selected patients with sufficient data to determine oligoclonal bands positivity, MRI dissemination in space and time, IgG index and sufficient quantities of paired CSF and blood samples to determine kappa free light chain indexes (n = 214). We used Kendall's Tau coefficient to estimate concordance, calculated the number of additional diagnoses when adding each positive index to dissemination in space and positive oligoclonal bands, performed survival analyses for oligoclonal bands and each index with the outcomes second attack and 2017 MRI dissemination in space and time and estimated the diagnostic properties of oligoclonal bands and the different indexes for the previously mentioned outcomes at 5 years. Oligoclonal bands were positive in 138 patients (64.5%), kappa free light chain-5.9 in 136 (63.6%), kappa free light chain-6.6 in 135 (63.1%), kappa free light chain-10.61 in 126 (58.9%) and IgG index in 101 (47.2%). The highest concordance was between oligoclonal bands and kappa free light chain-6.6 (τ = 0.727) followed by oligoclonal bands and kappa free light chain-5.9 (τ = 0.716). Combining dissemination in space plus oligoclonal bands or kappa free light chain-5.9 increased the number of diagnosed patients by 11 (5.1%), with kappa free light chain-6.6 by 10 (4.7%), with kappa free light chain-10.61 by 9 (4.2%) and with IgG index by 3 (1.4%). Patients with positive oligoclonal bands or indexes reached second attack and MRI dissemination in space and time faster than patients with negative results (P < 0.0001 except IgG index in second attack: P = 0.016). In multivariable Cox models [adjusted hazard ratio (95% confidence interval)], the risk for second attack was very similar between kappa free light chain-5.9 [2.0 (0.9-4.3), P = 0.068] and kappa free light chain-6.6 [2.1 (1.1-4.2), P = 0.035]. The highest risk for MRI dissemination in space and time was demonstrated with kappa free light chain-5.9 [4.9 (2.5-9.6), P < 0.0001], followed by kappa free light chain-6.6 [3.4 (1.9-6.3), P < 0.0001]. Kappa free light chains-5.9 and -6.6 had a slightly higher diagnostic accuracy than oligoclonal bands for second attack (70.5, 71.1 and 67.8) and MRI dissemination in space and time (85.7, 85.1 and 81.0). Kappa free light chain indexes 5.9 and 6.6 performed slightly better than oligoclonal bands to assess multiple sclerosis risk and in terms of diagnostic accuracy. Given the concordance between oligoclonal bands and these indexes, we suggest using dissemination in space plus positive oligoclonal bands or positive kappa free light chain index as a modified criterion to diagnose multiple sclerosis.

Is humoral and cellular response to SARS-CoV-2 vaccine modified by DMT in patients with multiple sclerosis and other autoimmune diseases?

BACKGROUND: The effect of disease-modifying therapies on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine response is unclear. OBJECTIVES: We aim to determine the immunological responses to SARS-CoV-2 in multiple sclerosis (MS) and anti-CD20-treated patients with other autoimmune diseases (AID). METHODS: Humoral and cellular responses we determined before and 30-90 days after vaccination in patients with MS and anti-CD20-treated patients with other AID in two Catalan centers. RESULTS: 457 patients were enrolled. Findings showed that humoral response decreased under anti-CD20s or sphingosine 1-phosphate receptor modulators (S1PRM) and with longer treatment duration and increased after 4.5 months from the last anti-CD20 infusion. Cellular response decreased in S1PRM-treated. Patients on anti-CD20 can present cellular responses even in the absence of antibodies. CONCLUSION: Anti-CD20s and S1PRM modify the immunological responses to SARS-CoV-2 vaccines.

Humoral and Cellular Responses to SARS-CoV-2 in Convalescent COVID-19 Patients With Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: Information about humoral and cellular responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and antibody persistence in convalescent (COVID-19) patients with multiple sclerosis (PwMS) is scarce. The objectives of this study were to investigate factors influencing humoral and cellular responses to SARS-CoV-2 and its persistence in convalescent COVID-19 PwMS. METHODS: This is a retrospective study of confirmed COVID-19 convalescent PwMS identified between February 2020 and May 2021 by SARS-CoV-2 antibody testing. We examined relationships between demographics, MS characteristics, disease-modifying therapy (DMT), and humoral (immunoglobulin G against spike and nucleocapsid proteins) and cellular (interferon-gamma [IFN-γ]) responses to SARS-CoV-2. RESULTS: A total of 121 (83.45%) of 145 PwMS were seropositive, and 25/42 (59.5%) presented a cellular response up to 13.1 months after COVID-19. Anti-CD20-treated patients had lower antibody titers than those under other DMTs (p < 0.001), but severe COVID-19 and a longer time from last infusion increased the likelihood of producing a humoral response. IFN-γ levels did not differ among DMT. Five of 7 (71.4%) anti--CD20-treated seronegative patients had a cellular response. The humoral response persisted for more than 6 months in 41/56(81.13%) PwMS. In multivariate analysis, seropositivity decreased due to anti-CD20 therapy (OR 0.08 [95% CI 0.01-0.55]) and increased in males (OR 3.59 [1.02-12.68]), whereas the cellular response decreased in those with progressive disease (OR 0.04 [0.001-0.88]). No factors were associated with antibody persistence. DISCUSSION: Humoral and cellular responses to SARS-CoV-2 are present in COVID-19 convalescent PwMS up to 13.10 months after COVID-19. The humoral response decreases under anti-CD20 treatment, although the cellular response can be detected in anti-CD20-treated patients, even in the absence of antibodies.

Impact of COVID-19 pandemic on frequency of clinical visits, performance of MRI studies, and therapeutic choices in a multiple sclerosis referral centre.

INTRODUCTION: To evaluate the impact of the COVID-19 pandemic on (1) number of clinical visits, (2) magnetic resonance (MR) scans, and (3) treatment prescriptions in a multiple sclerosis (MS) referral centre. METHODS: Retrospective study covering January 2018 to May 2021. RESULTS: The monthly mean (standard deviation [SD]) of visits performed in 2020 (814[137.6]) was similar to 2018 (741[99.7]; p = 0.153), and 2019 (797[116.3]; p = 0.747). During the COVID-19 period (2020 year), 36.3% of the activity was performed through telemedicine. The number of MR scans performed dropped by 76.6% during the "first wave" (March 14 to June 21, 2020) compared to the mean monthly activity in 2020 (183.5[68.9]), with a recovery during the subsequent two months. The monthly mean of treatment prescriptions approved in 2020 (24.1[7.0]) was lower than in 2019 (30[7.0]; p = 0.049), but similar to 2018 (23.8[8.0]; p = 0.727). Natalizumab prescriptions increased in the "first wave" and onwards, whereas anti-CD20 prescriptions decreased during the COVID-19 period. CONCLUSION: Maintenance of the number of clinical visits was likely due to telemedicine adoption. Although the number of MR dramatically dropped during the "first wave", an early recovery was observed. Treatment prescriptions suffered a slight quantitative decrease during 2020, whereas substantial qualitative changes were found in specific treatments.

Immunomodulatory Effects Associated with Cladribine Treatment.

Cladribine is a synthetic deoxyadenosine analogue with demonstrated efficacy in patients with relapsing-remitting multiple sclerosis (MS). The main mechanism of action described for cladribine is the induction of a cytotoxic effect on lymphocytes, leading to a long-term depletion of peripheral T and B cells. Besides lymphocyte toxicity, the mode of action may include immunomodulatory mechanisms affecting other cells of the immune system. In order to induce its beneficial effects, cladribine is phosphorylated inside the cell by deoxycytidine kinase (DCK) to its active form. However, the mechanism of action of cladribine may also include immunomodulatory pathways independent of DCK activation. This in vitro study was designed to explore the impact of cladribine on peripheral blood mononuclear cells (PBMC) subsets, and to assess whether the immunomodulatory mechanisms induced by cladribine depend on the activation of the molecule. To this end, we obtained PBMCs from healthy donors and MS patients and performed proliferation, apoptosis and activation assays with clinically relevant concentrations of cladribine in DCK-dependent and -independent conditions. We also evaluated the effect of cladribine on myeloid lineage-derived cells, monocytes and dendritic cells (DCs). Cladribine decreased proliferation and increased apoptosis of lymphocyte subsets after prodrug activation via DCK. In contrast, cladribine induced a decrease in immune cell activation through both DCK-dependent and -independent pathways (not requiring prodrug activation). Regarding monocytes and DCs, cladribine induced cytotoxicity and impaired the activation of classical monocytes, but had no effect on DC maturation. Taken together, these data indicate that cladribine, in addition to its cytotoxic function, can mediate immunomodulation in different immune cell populations, by regulating their proliferation, maturation and activation.

Immunosenescence in multiple sclerosis: the identification of new therapeutic targets.

The number of elderly multiple sclerosis (MS) patients is growing, mainly due to the increase in the life expectancy of the general population and the availability of effective disease-modifying treatments. However, current treatments reduce the frequency of relapses and slow the progression of the disease, but they cannot stop the disability accumulation associated with disease progression. One possible explanation is the impact of immunosenescence, which is associated with the accumulation of unusual immune cell subsets that are thought to have a role in the development of an early ageing process in autoimmunity. Here, we provide a recent overview of how senescence affects immune cell function and how it is involved in the pathogenesis of autoimmune diseases, particularly MS. Numerous studies have demonstrated age-related immune changes in experimental autoimmune encephalomyelitis models, and the premature onset of immunosenescence has been demonstrated in MS patients. Therefore, potential therapeutic strategies based on rejuvenating the immune system have been proposed. Senolytics and regenerative strategies using haematopoietic stem cells, therapies based on rejuvenating oligodendrocyte precursor cells, microglia and monocytes, thymus cells and senescent B and T cells are capable of reversing the process of immunosenescence and could have a beneficial impact on the progression of MS.

Identification of the Immunological Changes Appearing in the CSF During the Early Immunosenescence Process Occurring in Multiple Sclerosis.

Patients with multiple sclerosis (MS) suffer with age an early immunosenescence process, which influence the treatment response and increase the risk of infections. We explored whether lipid-specific oligoclonal IgM bands (LS-OCMB) associated with highly inflammatory MS modify the immunological profile induced by age in MS. This cross-sectional study included 263 MS patients who were classified according to the presence (M+, n=72) and absence (M-, n=191) of LS-OCMB. CSF cellular subsets and molecules implicated in immunosenescence were explored. In M- patients, aging induced remarkable decreases in absolute CSF counts of CD4+ and CD8+ T lymphocytes, including Th1 and Th17 cells, and of B cells, including those secreting TNF-alpha. It also increased serum anti-CMV IgG antibody titers (indicative of immunosenescence) and CSF CHI3L1 levels (related to astrocyte activation). In contrast, M+ patients showed an age-associated increase of TIM-3 (a biomarker of T cell exhaustion) and increased values of CHI3L1, independently of age. Finally, in both groups, age induced an increase in CSF levels of PD-L1 (an inductor of T cell tolerance) and activin A (part of the senescence-associated secretome and related to inflammaging). These changes were independent of the disease duration. Finally, this resulted in augmented disability. In summary, all MS patients experience with age a modest induction of T-cell tolerance and an activation of the innate immunity, resulting in increased disability. Additionally, M- patients show clear decreases in CSF lymphocyte numbers, which could increase the risk of infections. Thus, age and immunological status are important for tailoring effective therapies in MS.

Selected Clostridia Strains from The Human Microbiota and their Metabolite, Butyrate, Improve Experimental Autoimmune Encephalomyelitis.

Gut microbiome studies in multiple sclerosis (MS) patients are unravelling some consistent but modest patterns of gut dysbiosis. Among these, a significant decrease of Clostridia cluster IV and XIVa has been reported. In the present study, we investigated the therapeutic effect of a previously selected mixture of human gut-derived 17 Clostridia strains, which belong to Clostridia clusters IV, XIVa, and XVIII, on the clinical outcome of experimental autoimmune encephalomyelitis (EAE). The observed clinical improvement was related to lower demyelination and astrocyte reactivity as well as a tendency to lower microglia reactivity/infiltrating macrophages and axonal damage in the central nervous system (CNS), and to an enhanced immunoregulatory response of regulatory T cells in the periphery. Transcriptome studies also highlighted increased antiinflammatory responses related to interferon beta in the periphery and lower immune responses in the CNS. Since Clostridia-treated mice were found to present higher levels of the immunomodulatory short-chain fatty acid (SCFA) butyrate in the serum, we studied if this clinical effect could be reproduced by butyrate administration alone. Further EAE experiments proved its preventive but slight therapeutic impact on CNS autoimmunity. Thus, this smaller therapeutic effect highlighted that the Clostridia-induced clinical effect was not exclusively related to the SCFA and could not be reproduced by butyrate administration alone. Although it is still unknown if these Clostridia strains will have the same effect on MS patients, gut dysbiosis in MS patients could be partially rebalanced by these commensal bacteria and their immunoregulatory properties could have a beneficial effect on MS clinical course.

How oral probiotics affect the severity of an experimental model of progressive multiple sclerosis? Bringing commensal bacteria into the neurodegenerative process.

A growing number of studies support that the bidirectional interactions between the gut microbiota, the immune system and the CNS are relevant for the pathophysiology of MS. Several studies have reported alterations in the gut microbiome of MS patients. In addition, a variety of studies in animal models of MS have suggested that specific members of the gut commensal microbiota can exacerbate or ameliorate neuroinflammation. Probiotics represent oral nontoxic immunomodulatory agents that would exert benefits when using in combination with current MS therapy. Here we investigate the effect of Vivomixx on the gut microbiome and central and peripheral immune responses in a murine model of primary progressive MS. Vivomixx administration was associated with increased abundance of many taxa such as Bacteroidetes, Actinobacteria, Tenericutes and TM7. This was accompanied by a clear improvement of the motor disability of Theiler's virus infected mice; in the CNS Vivomixx reduced microgliosis, astrogliosis and leukocyte infiltration. Notably, the presence of Breg cells (CD19+CD5+CD1dhigh) in the CNS was enhanced by Vivomixx, and while spinal cord gene expression of IL-1ß and IL-6 was diminished, the probiotic promoted IL-10 gene expression. One of the most significant findings was the increased plasma levels of butyrate and acetate levels in TMEV-mice that received Vivomixx. Peripheral immunological changes were subtle but interestingly, the probiotic restricted IL-17 production by Th17-polarized CD4+ T-cells purified from the mesenteric lymph nodes of Theiler's virus infected mice. Our data reinforce the beneficial effects of oral probiotics that would be coadjuvant treatments to current MS therapies.

Inhibition of the BMP Signaling Pathway Ameliorated Established Clinical Symptoms of Experimental Autoimmune Encephalomyelitis.

Bone morphogenetic proteins (BMPs) are secreted growth factors that belong to the transforming growth factor beta superfamily. BMPs have been implicated in physiological processes, but they are also involved in many pathological conditions. Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system (CNS); however, its etiology remains elusive. Some evidence points to BMPs as important players in the pathogenesis of inflammatory and autoimmune disorders. In the present work, we studied the expression of BMP2, BMP4, BMP5, BMP6, BMP7, BMP type II receptor, and noggin in the immune system during different phases of experimental autoimmune encephalomyelitis (EAE). Major changes in the expression of BMPs took place in the initial phases of EAE. Indeed, those changes mainly affected BMP6 (whose expression was abrogated), BMP2, and BMP7 (whose expression was increased). In addition, we showed that in vivo inhibition of the BMP signaling pathway with small molecules ameliorated the already established clinical symptoms of EAE, as well as the CNS histopathological features. At the immune level, we observed an expansion of plasmacytoid dendritic cells (pDCs) in mice treated with small molecules that inhibit the BMP signaling pathway. pDCs could play an important role in promoting the expansion of antigen-specific regulatory T cells. Altogether, our data suggest a role for BMPs in early immune events that take place in myelin oligodendrocyte glycoprotein (MOG)-induced EAE. In addition, the clinical outcome of the disease was improved when the BMP signaling pathway was inhibited in mice that presented established EAE symptoms.

A Commercial Probiotic Induces Tolerogenic and Reduces Pathogenic Responses in Experimental Autoimmune Encephalomyelitis.

Previous studies in experimental autoimmune encephalomyelitis (EAE) models have shown that some probiotic bacteria beneficially impact the development of this experimental disease. Here, we tested the therapeutic effect of two commercial multispecies probiotics-Lactibiane iki and Vivomixx-on the clinical outcome of established EAE. Lactibiane iki improves EAE clinical outcome in a dose-dependent manner and decreases central nervous system (CNS) demyelination and inflammation. This clinical improvement is related to the inhibition of pro-inflammatory and the stimulation of immunoregulatory mechanisms in the periphery. Moreover, both probiotics modulate the number and phenotype of dendritic cells (DCs). Specifically, Lactibiane iki promotes an immature, tolerogenic phenotype of DCs that can directly induce immune tolerance in the periphery, while Vivomixx decreases the percentage of DCs expressing co-stimulatory molecules. Finally, gut microbiome analysis reveals an altered microbiome composition related to clinical condition and disease progression. This is the first preclinical assay that demonstrates that a commercial probiotic performs a beneficial and dose-dependent effect in EAE mice and one of the few that demonstrates a therapeutic effect once the experimental disease is established. Because this probiotic is already available for clinical trials, further studies are being planned to explore its therapeutic potential in multiple sclerosis patients.

NLRP3 inflammasome as prognostic factor and therapeutic target in primary progressive multiple sclerosis patients.

Primary progressive multiple sclerosis is a poorly understood disease entity with no specific prognostic biomarkers and scarce therapeutic options. We aimed to identify disease activity biomarkers in multiple sclerosis by performing an RNA sequencing approach in peripheral blood mononuclear cells from a discovery cohort of 44 untreated patients with multiple sclerosis belonging to different clinical forms and activity phases of the disease, and 12 healthy control subjects. A validation cohort of 58 patients with multiple sclerosis and 26 healthy control subjects was included in the study to replicate the RNA sequencing findings. The RNA sequencing revealed an interleukin 1 beta (IL1B) signature in patients with primary progressive multiple sclerosis. Subsequent immunophenotyping pointed to blood monocytes as responsible for the IL1B signature observed in this group of patients. Functional experiments at baseline measuring apoptosis-associated speck-like protein containing a CARD (ASC) speck formation showed that the NOD-leucine rich repeat and pyrin containing protein 3 (NLRP3) inflammasome was overactive in monocytes from patients with primary progressive multiple sclerosis, and canonical NLRP3 inflammasome activation with a combination of ATP plus lipopolysaccharide was associated with increased IL1B production in this group of patients. Primary progressive multiple sclerosis patients with high IL1B gene expression levels in peripheral blood mononuclear cells progressed significantly faster compared to patients with low IL1B levels based on the time to reach an EDSS of 6.0 and the Multiple Sclerosis Severity Score. In agreement with peripheral blood findings, both NLRP3 and IL1B expression in brain tissue from patients with primary progressive multiple sclerosis was mainly restricted to cells of myeloid lineage. Treatment of mice with a specific NLRP3 inflammasome inhibitor attenuated established experimental autoimmune encephalomyelitis disease severity and improved CNS histopathology. NLRP3 inflammasome-specific inhibition was also effective in reducing axonal damage in a model of lipopolysaccharide-neuroinflammation using organotypic cerebellar cultures. Altogether, these results point to a role of IL1B and the NLRP3 inflammasome as prognostic biomarker and potential therapeutic target, respectively, in patients with primary progressive multiple sclerosis.

New Algorithms Improving PML Risk Stratification in MS Patients Treated With Natalizumab.

Overview: We assessed the role of age and disease activity as new factors contributing to establish the risk of progressive multifocal leucoencephalopathy in multiple sclerosis patients treated with natalizumab in 36 University Hospitals in Europe. We performed the study in 1,307 multiple sclerosis patients (70.8% anti-John Cunninghan virus positive antibodies) treated with natalizumab for a median time of 3.28 years. Epidemiological, clinical, and laboratory variables were collected. Lipid-specific IgM oligoclonal band status was available in 277 patients. Factors associated with progressive multifocal leucoencephalopathy onset were explored by uni- and multivariate logistic regression. Results: Thirty-five patients developed progressive multifocal leucoencephalopathy. The multivariate analysis identified anti-John Cunninghan virus antibody indices and relapse rate as the best predictors for the onset of this serious opportunistic infection in the whole cohort. They allowed to stratify progressive multifocal leucoencephalopathy risk before natalizumab initiation in individual patients [area under the curve (AUC) = 0.85]. The risk ranged from <1/3,300 in patients with anti-John Cunninghan virus antibody indices <0.9 and relapse rate >0.5, to 1/50 in the opposite case. In patients with lipid-specific IgM oligoclonal bands assessment, age at natalizumab onset, anti-John Cunninghan virus antibody indices, and lipid-specific IgM oligoclonal band status predicted progressive multifocal leucoencephalopathy risk (AUC = 0.92). The absence of lipid-specific IgM oligoclonal bands was the best individual predictor (OR = 40.94). The individual risk ranged from <1/10,000 in patients younger than 45 years at natalizumab initiation, who showed anti John Cunningham virus antibody indices <0.9 and lipid-specific IgM oligoclonal bands to 1/33 in the opposite case. Conclusions: In a perspective of personalized medicine, disease activity, anti-lipid specific IgM oligoclonal bands, anti Jonh Cunninghan virus antibody levels, and age can help tailor natalizumab therapy in multiple sclerosis patients, as predictors of progressive multifocal leucoencephalopathy.