Gut-oriented interventions in patients with multiple sclerosis: fact or fiction?

OBJECTIVE: Multiple sclerosis (MS) is a chronic, inflammatory, demyelinating, disimmune disease of the central nervous system whose etiology and pathogenesis remain poorly understood, due to its complex and multifactorial nature. Evidence of a bidirectional connection linking the gut microbiome with the intestinal barrier and the immune system (the gut-brain axis) may have implications for the pathogenesis of inflammatory demyelinating diseases such as MS. This narrative review summarizes the evidence for the gut-brain axis involvement in the pathogenesis of MS and examines the role of gut-oriented interventions in MS. PATIENTS AND METHODS: We reviewed all available studies in PubMed concerning gut-directed interventions and MS. This research was conducted using different combinations of pertinent keywords (multiple sclerosis, immune-mediated inflammatory diseases, autoimmune diseases, first demyelinating event, neurocognition, neurological disorders, neurology practice, risk factors, taxonomic biomarkers, nutrition, diet, dietary additives, complementary treatment, gut bacteria, gut microbiome, microbiome, gut-brain axis, epidemiology, alpha-linolenic acid, fermentative metabolites, fat, saturated fat, monounsaturated fat, polyunsaturated fat, omega-3 fatty acids, calorie restricted diet, fasting, fecal microbiome, fecal microbiota transplantation, animal testing). RESULTS: There is an emerging evidence that alterations in the gut microbiome and increased intestinal permeability may be causative factors in the complex interplay between nutrition, metabolic status and the immune-inflammatory response in patients with MS. This suggests the possibility that modification of lifestyle and the microbiome, for example by specific diets or fecal microbiota transplantation, supplementation with bile acids and intestinal barrier enhancers, may positively influence the pathogenesis of MS. CONCLUSIONS: Although the role of nutritional factors in the pathogenesis of MS remains to be established, there is evidence that appropriate gut-directed interventions such as diet, nutritional supplementation or fecal transplantation may modulate the inflammatory response and improve the course of MS as a complementary treatment in the disease.

Lymphocyte subsets as biomarkers of therapeutic response in Fingolimod treated Relapsing Multiple Sclerosis patients.

We investigated, lymphocyte count (LC) and lymphocyte subpopulations (LS) in a real life setting of Fingolimod (FTY) treated Relapsing MS (RMS) patients. Peripheral blood counts with LS, relapses and MRI scans were recorded in a cohort of 119 FTY patients, during one year of treatment. Simple and multivariate logistic regression models, were performed. ROC analysis identified cut-off values of LS predicting a higher risk of relapses and of Gd+ lesions. We demonstrated a FTY-induced re-modulation of the immune system, suggesting that LS in RMS FTY treated patients can predict the clinical response to the drug.

Conversion from clinically isolated syndrome to multiple sclerosis: A large multicentre study.

BACKGROUND AND OBJECTIVE: We explored which clinical and biochemical variables predict conversion from clinically isolated syndrome (CIS) to clinically definite multiple sclerosis (CDMS) in a large international cohort. METHODS: Thirty-three centres provided serum samples from 1047 CIS cases with at least two years' follow-up. Age, sex, clinical presentation, T2-hyperintense lesions, cerebrospinal fluid (CSF) oligoclonal bands (OCBs), CSF IgG index, CSF cell count, serum 25-hydroxyvitamin D3 (25-OH-D), cotinine and IgG titres against Epstein-Barr nuclear antigen 1 (EBNA-1) and cytomegalovirus were tested for association with risk of CDMS. RESULTS: At median follow-up of 4.31 years, 623 CIS cases converted to CDMS. Predictors of conversion in multivariable analyses were OCB (HR = 2.18, 95% CI = 1.71-2.77, p < 0.001), number of T2 lesions (two to nine lesions vs 0/1 lesions: HR = 1.97, 95% CI = 1.52-2.55, p < 0.001; >9 lesions vs 0/1 lesions: HR = 2.74, 95% CI = 2.04-3.68, p < 0.001) and age at CIS (HR per year inversely increase = 0.98, 95% CI = 0.98-0.99, p < 0.001). Lower 25-OH-D levels were associated with CDMS in univariable analysis, but this was attenuated in the multivariable model. OCB positivity was associated with higher EBNA-1 IgG titres. CONCLUSIONS: We validated MRI lesion load, OCB and age at CIS as the strongest independent predictors of conversion to CDMS in this multicentre setting. A role for vitamin D is suggested but requires further investigation.

Cerebrospinal fluid neurofilament tracks fMRI correlates of attention at the first attack of multiple sclerosis.

BACKGROUND: Identifying markers of cognitive dysfunction in multiple sclerosis (MS) is extremely challenging since it means supplying potential biomarkers for neuroprotective therapeutic strategies. OBJECTIVE: The aim of this study is to investigate the relationship between fMRI correlates of attention performance and cerebrospinal fluid (CSF) neurofilament light chain (NFL) levels in patients with clinically isolated syndrome (CIS) suggestive of MS. METHODS: Twenty-one untreated, cognitively preserved CIS patients underwent BOLD-fMRI while performing the Variable Attentional Control (VAC) task, a cognitive paradigm requiring increasing levels of attentional control processing. CSF NFL was assessed by ELISA technique. SPM8 random-effects models were used for statistical analyses of fMRI data (p<0.05 corrected). RESULTS: Repeated-measures ANOVA on imaging data showed an interaction between attentional control load and NFL levels in the right putamen. At the high level of attentional control demand CIS patients with "low NFL levels" showed greater activity in the putamen compared with subjects with "high NFL levels" (p=0.001). These results are independent of cognitive impairment index. CONCLUSIONS: Our findings suggest a relationship between CSF NFL levels and load-dependent failure of putaminal recruitment pattern during sustained attention in CIS and suggest a role of CSF NFL as a marker of subclinical abnormality of cognitive pathway recruitment in CIS.

The impact of neutralizing antibodies on the risk of disease worsening in interferon ß-treated relapsing multiple sclerosis: a 5 year post-marketing study.

The impact of neutralizing antibodies (NAbs) on interferon ß (IFNß) efficacy in MS patients is still an object of controversy. To evaluate the clinical response to IFNß during NAb-positive (NAb+) and NAb-negative (NAb-) statuses on a large population of relapsing remitting (RR) MS patients were followed up to 5 years. Sera from 567 RR MS patients treated with IFNß for 2-5 years were collected every 6-12 months and evaluated for NAb presence by a cytopathic effect assay. The relapse rate and expanded disability status scale (EDSS) score were assessed at baseline and every 6 months for each patient. A NAb+ status was defined after two consecutive positive titers of NAbs >/= 20 neutralizing units (NU)/mL. Multivariate models were used to analyze the relapse rate, the time to first relapse, the time to confirmed EDSS score 4 during NAb+ and NAb- statuses. A propensity score (PS) matching analysis was performed to assess the robustness of the multivariate models. Fourteen percent of patients became NAb+ during the follow-up. A significant increase of the relapse rate (IRR = 1.38; p = 0.0247) and decrease of the time to 1st relapse (IRR = 1.51; p = 0.0111) were found during NAb+ periods. The PS matching analysis, in a selected cohort of patients, demonstrated a negative trend of NAbs on the time to reach the milestone EDSS 4 (IRR = 2.94; p = 0.0879). This long-term post-marketing observational study further confirms that the occurrence of NAbs significantly affects the risk of disease worsening in IFNß- treated RRMS.

Load-dependent dysfunction of the putamen during attentional processing in patients with clinically isolated syndrome suggestive of multiple sclerosis.

BACKGROUND: Load-related functional magnetic resonance imaging (fMRI) abnormalities of brain activity during performance of attention tasks have been described in definite multiple sclerosis (MS). No data are available in clinically isolated syndrome (CIS) suggestive of MS. OBJECTIVES: The objective of this research is to evaluate in CIS patients the fMRI pattern of brain activation during an attention task and to explore the effect of increasing task load demand on neurofunctional modifications. METHODS: Twenty-seven untreated CIS patients and 32 age- and sex-matched healthy controls (HCs) underwent fMRI while performing the Variable Attentional Control (VAC) task, a cognitive paradigm requiring increasing levels of attentional control processing. Random-effects models were used for statistical analyses of fMRI data. RESULTS: CIS patients had reduced accuracy and greater reaction time at the VAC task compared with HCs (p=0.007). On blood oxygenation level-dependent (BOLD)-fMRI, CIS patients had greater activity in the right parietal cortex (p=0.0004) compared with HCs. Furthermore, CIS patients had greater activity at the lower (p=0.05) and reduced activity at the greater (p=0.04) level of attentional control demand in the left putamen, compared with HCs. CONCLUSIONS: This study demonstrates the failure of attentional control processing in CIS. The load-related fMRI dysfunction of the putamen supports the role of basal ganglia in the failure of attention observed at the earliest stage of MS.

Serum and CSF N-acetyl aspartate levels differ in multiple sclerosis and neuromyelitis optica.

BACKGROUND: The identification of biomarkers able to improve the differential diagnosis between multiple sclerosis (MS) and neuromyelitis optica (NMO) is challenging because of a different prognosis and response to treatment. Growing evidence indicates that brain and CSF N-acetyl aspartate (NAA) concentration is a useful marker for characterising different phases of axonal pathology in demyelinating diseases, and preliminary studies suggest that increased serum NAA levels may be a telltale sign of acute neuronal damage or defective NAA metabolism in oligodendrocytes. OBJECTIVE: To evaluate whether serum and CSF NAA concentration differs in patients with MS and NMO. DESIGN: Observational, multicentre, prospective, cross sectional study. METHODS: Serum samples were collected from 48 relapsing-remitting MS, 32 NMO and 76 age matched healthy controls. Coeval CSF samples were available for all MS and for 8/32 NMO patients. NAA was measured in serum and CSF by liquid chromatography-mass spectrometry. RESULTS: MS patients showed higher serum and CSF NAA levels than NMO patients, and higher serum NAA levels than healthy controls (p<0.001). High serum NAA values, exceeding the 95th percentile of serum NAA values in healthy controls, were found in 100% of patients with MS and in no patient with NMO. No differences in serum NAA levels were found between NMO and healthy controls. In MS, serum and CSF NAA levels correlated with disability score. CONCLUSIONS: Determination of serum and CSF NAA levels may represent a suitable tool in the diagnostic laboratory workup to differentiate MS and NMO.

Post-marketing of disease modifying drugs in multiple sclerosis: an exploratory analysis of gender effect in interferon beta treatment.

BACKGROUND: There are a few and conflicting results from randomised controlled trials (RCTs) pertaining to the influence of gender in response to currently used disease modifying drugs in Multiple Sclerosis (MS). Observational studies may be especially valuable for answering effectiveness questions in subgroups not studied in RCTs. OBJECTIVE: To conduct a post-marketing analysis aimed to evaluate the gender effect on Interferon beta (IFNbeta) treatment response in a cohort of relapsing (RR) MS patients. METHODS: A cohort of 2570 IFNbeta-treated RRMS was prospectively followed for up to 7 years in 15 Italian MS Centers. Cox proportional hazards regression models were used to assess gender differences for risk of reaching 1st relapse and risk of progression by 1 point on Expanded Disability Status Scale (EDSS) score. Gender effects were also explored by a propensity score (PS) matching algorithm, and a tree-growing technique. RESULTS: The multivariate Cox Regression analyses showed that male patients had a significant (p=0.0097) lower risk for 1st relapse and a trend (p=0.0897) for a higher risk to reach 1 point EDSS progression than females. The PS matched multivariate Cox Regression confirmed these results. The RECPAM analysis showed that male sex conferred a significant reduction in the risk for 1st relapse (HR=0.86; 95% CI=0.76-0.98; p=0.0226) in the subgroup with a low pre-treatment number of bouts, and a significant increase in the risk for 1 point EDSS progression (HR=1.33; 95% CI: 1.00-1.76; p<0.05) in the subgroup with a delayed treatment, but a still young age at the start of treatment. CONCLUSION: The results of this exploratory analysis seem to suggest that male patients do not respond to IFNbeta treatment in the same way of females.