Beta-interferon exposure and onset of secondary progressive multiple sclerosis

Using instrumental variables to correct for bias in real-world cohort studies of the effects of disease-modifying treatment in MS

BACKGROUND

Estimating the effect of disease-modifying treatment of MS in observational studies is impaired by bias from unmeasured confounders, in particular indication bias.

OBJECTIVE

To show how instrumental variables (IVs) reduce bias.

METHODS

All patients with relapsing onset of MS 1996-2010, identified by the nationwide Danish Multiple Sclerosis Registry, were followed from onset. Exposure was treatment index throughout the first 12 years from onset, defined as a cumulative function of months without and with medium- or high-efficacy treatment, and outcomes were hazard ratios (HRs) per unit treatment index for sustained Expanded Disability Scale Score (EDSS) 4 and 6 adjusted for age at onset and sex, without and with an IV. We used the onset cohort (1996-2000; 2001-2005; 2006-2010) as an IV because treatment index increased across the cohorts.

RESULTS

We included 6014 patients. With conventional Cox regression, HRs for EDSS 4 and 6 were 1.15 [95% CI: 1.13-1.18] and 1.17 [1.13-1.20] per unit treatment index. Only with IVs, we confirmed a beneficial effect of treatment with HRs of 0.86 [0.81-0.91] and 0.82 [0.74-0.90].

CONCLUSION

The use of IVs eliminates indication bias and confirms that treatment is effective in delaying disability. IVs could, under some circumstances, be an alternative to marginal structural models.

Effectiveness of first generation disease-modifying therapy to prevent conversion to secondary progressive multiple sclerosis

BACKGROUND

The use of disease-modifying therapies (DMTs) in multiple sclerosis (MS) has been associated with reduced relapse rates and accumulation of disability. However, studies examining impact of DMT on risk of transition to secondary progressive MS (SPMS) leveraging population-based nationwide data are still rare. Here, we determine the population incidence of conversion to SPMS using two consecutive nation-wide cohorts, one immediately before and one after the introduction of DMT in Sweden.

METHODS

We included two consecutive population cohorts of relapsing-remitting MS (RRMS) from the Swedish national MS register for the periods 1975-1994 (n = 2161), before DMT availability, and 1995-2011 (n = 3510), in which DMTs, mainly first generation DMT (injectables), became available and eventually were used by 70% of patients. We explored the risk of transition to SPMS as a calendar year function encompassing the two cohorts. In addition, we determined the incidence of transition to SPMS through age strata below and above 50 years in untreated and treated patient subgroups.

RESULTS

The risk of conversion to SPMS (adjusted for current age, current time since onset, calendar year and sex) was significantly lower in the second compared with the first population cohort (hazard ratio 0.58; CI 0.48, 0.70). The risk of SPMS conversion per calendar year decreased by 2.6% annually (p < 0.001) after 1995. The risk of SPMS conversion increased with age until age 50. Thereafter, it was unchanged or decreased among those with early MS onset age (<35 years), but continued to increase with onset at higher age, with similar trends in treated and untreated subgroups.

CONCLUSION

The incidence of SPMS conversion significantly decreased at the population level after introduction of first generation DMTs by 1995. DMT efficiency was confirmed by a downward turn of the annual trajectory of the risk of SPMS conversion after 1995. An onset age determined pattern of variable SPMS incidence in higher age appeared in both treated and untreated strata. While first generation DMT delayed conversion to SPMS, their long-term effect was only moderate.

Community Awareness Toward Multiple Sclerosis in the Western Region of Saudi Arabia: A Cross-Sectional Study

Objectives: The aim of this study is to assess the awareness level and knowledge about multiple sclerosis (MS) disease among the general population in the Western region of Saudi Arabia. 

Methods: This study was a community-based cross-sectional descriptive study carried on by an online questionnaire, previously validated in published studies, to all residents in the western region of Saudi Arabia who successfully fulfilled the inclusion and exclusion criteria a total number of 4038. 

Results: Out of the total number of respondents (n=3,536), the majority 46% (1,625) showed a low level of knowledge, while 31% (1,116) have an average level of knowledge, and 22.5% (795) have a high level of knowledge. Various factors including age, gender and socioeconomic status showed a potential association. 

Conclusion: This community-based survey showed a low level of knowledge in regard to MS in the Western region of Saudi Arabia. Multiple variables showed potential associations that can be utilized to efficiently direct governmental and non-governmental health organizations' efforts to maximize awareness of this condition to aid early recognition and early treatment in the hope of better outcomes.

Reduction in CD11c+ microglia correlates with clinical progression in chronic experimental autoimmune demyelination

Multiple sclerosis (MS) is a chronic autoimmune demyelinating disease with high variability of clinical symptoms. In most cases MS appears as a relapsing-remitting disease course that at a later stage transitions into irreversible progressive decline of neurologic function. The mechanisms underlying MS progression remain poorly understood. Experimental autoimmune encephalomyelitis (EAE) is an animal model of MS. Here we demonstrate that mice that develop mild EAE after immunization with myelin oligodendrocyte glycoprotein 35-55 are prone to undergo clinical progression around 30 days after EAE induction. EAE progression was associated with reduction in CD11c⁺ microglia and dispersed coalescent parenchymal infiltration. We found sex-dependent differences mediated by p38α signaling, a key regulator of inflammation. Selective reduction of CD11c⁺ microglia in female mice with CD11c-promoter driven p38α knockout correlated with increased rate of EAE progression. In protected animals, we found CD11c⁺ microglia forming contacts with astrocyte processes at the glia limitans and immune cells retained within perivascular spaces. Together, our study identified pathological hallmarks of chronic EAE progression and suggests that CD11c⁺ microglia may regulate immune cell parenchymal infiltration in autoimmune demyelination.

MicroRNA-7188-5p and miR-7235 regulates Multiple sclerosis in an experimental mouse model

The short non-coding microRNAs (miRNAs) have emerged as reliable modulators of various pathological conditions including autoimmune diseases in mammals. The current study, aims to identify new potential differential expressed miRNAs and their downstream mRNA targets of the autoimmune disease, Multiple sclerosis (MS). The study identifies a new set of miRNA(s) that are probably implicated in MS using computational tools. The study further carried-out different in vivo and in vitro experiments to check these identified miRNAs could be role in as therapeutic and prognostic applications. Preliminary insilico screening revealed that miR-659-3p, miR-659-5p, miR-684, miR-3607-3p, miR-3607-5p, miR-3682-3p, miR-3682-5p miR-4647, miR-7188-3p, miR-7188-5p and miR-7235 are specifically elevated in the secondary lymphoid cells of EAE mice. In addition, expression of the downstream target mRNA of these miRNAs such as FXBO33, SGMS-1, ZDHHC-9, GABRA-3, NRXN-2 were reciprocal to miRNA expression in lymphoid cells. These confirmed by applying the mimic and silencing miRNA models, suggesting new inflammatory target genes of these promising miRNA markers. The in vivo adoptive transfer model revealed that the suppression of miRNA-7188-5p and miR-7235 changed the pattern of astrocytes and CNS pathophysiology. The current study opens a new miRNA and their mRNA targets in MS disease. The absence of miRNA-7188-5p and miR-7235 enhanced the disease alleviation, confirms the regulatory effect of these targets. These optimized results highlights new set of miRNA's with therapeutic potential in experimental MS. Further studies are required to confirm these miRNA as therapeutic biomarker.

Epidemiology of multiple sclerosis in Iraq: retrospective review of 4355 cases and literature review

OBJECTIVES

Multiple sclerosis (MS) is a progressive demyelinating and degenerative disease of the CNS, which is highly variable geographically. The objectives are to establish comprehensive nationwide MS epidemiological data and compare it with similar studies conducted in regional and international communities. To the best of our knowledge, this is the first nationwide comprehensive epidemiological study conducted in Iraq.

METHODS

This retrospective study is including 4355 MS cases from the 10 officially authorized MS clinics in Iraq from January 2000 to December 2018. All cases were diagnosed according to McDonald's criteria 2010, new cases diagnosed according to the new criteria of McDonald's criteria 2018. All patients' records were reviewed by the scientific committee.

RESULTS

Our study found that 68.51% of MS were females with female-to-male ratio 2.18:1 and 4.07% of patients were diagnosed before they reached 18 years of age. The mean age was 32.3 ± 9.8. The prevalence was found to be 11.73/100,000; it was 16.2/100,000 among females and 7.3/100,000 among males. The incidence was 0.05 in the year 2000 and 1.5 in the year 2017. Initial symptoms were visual 32.06%, motor 28.11%, and 25.58% were sensory symptoms, and 89.97% of the clinical form was relapsing/remitting MS (RRMS) and 81.65% of patients were on first-line treatment. Meanwhile, 66.97% of cases were diagnosed within weeks or months from symptom onset. Summer had the most frequencies regarding birth season.

CONCLUSIONS

MS has a significantly increased incidence in Iraq, while prevalence is low compared to neighboring countries. RRMS was the most common clinical form and visual symptoms showed the highest frequency of the first presenting symptoms.

Accurate classification of secondary progression in multiple sclerosis using a decision tree

BACKGROUND

The absence of reliable imaging or biological markers of phenotype transition in multiple sclerosis (MS) makes assignment of current phenotype status difficult.

OBJECTIVE

The authors sought to determine whether clinical information can be used to accurately assign current disease phenotypes.

METHODS

Data from the clinical visits of 14,387 MS patients in Sweden were collected. Classifying algorithms based on several demographic and clinical factors were examined. Results obtained from the best classifier when predicting neurologist recorded disease classification were replicated in an independent cohort from British Columbia and were compared to a previously published algorithm and clinical judgment of three neurologists.

RESULTS

A decision tree (the classifier) containing only most recently available expanded disability scale status score and age obtained 89.3% (95% confidence intervals (CIs): 88.8-89.8) classification accuracy, defined as concordance with the latest reported status. Validation in the independent cohort resulted in 82.0% (95% CI: 81.0-83.1) accuracy. A previously published classification algorithm with slight modifications achieved 77.8% (95% CI: 77.1-78.4) accuracy. With complete patient history of 100 patients, three neurologists obtained 84.3% accuracy compared with 85% for the classifier using the same data.

CONCLUSION

The classifier can be used to standardize definitions of disease phenotype across different cohorts. Clinically, this model could assist neurologists by providing additional information.

A non-parametric propensity score for estimating the effect of interferon-beta or glatiramer acetate on long-term outcomes of multiple sclerosis

BACKGROUND

The few observational studies that investigated the long-term effects of interferon-beta and glatiramer acetate were usually focused on progression to irreversible disability and other outcomes such as number of relapses and transition to secondary-progressive multiple sclerosis (SPMS) have been rarely studied. The objective of this paper is to estimate the effect of interferon-beta/glatiramer acetate on progression to irreversible disability, transition from relapsing-remitting multiple sclerosis (RRMS) to SPMS and the rate of relapses over 10 years.

METHODS

Analyses included 2498 patients with confirmed diagnosis of RRMS followed in Montréal from 1977 to 2016. Marginal structural models with propensity score for treatment and censoring were used to account for potential confounding and attrition. Specifically, we used pooled logistic regression for progression to irreversible disability and transition to SPMS, and Poisson models for the rate of relapses.

RESULTS

77% of subjects were female and the median age at RRMS diagnosis was 35 years. The hazard of progression to irreversible disability was lower among treated patients than untreated patients (HR=0.73, 95% CI [0.57-0.94]). We did not find evidence of an association between interferon-beta/glatiramer acetate and the rate of transition to SPMS either over the 3-month intervals or for the duration of treatment. Patients treated for >5 years had a lower rate of relapses compared to those untreated (HR=0.70, 95% CI [0.57-0.86]).

CONCLUSION

Treatment with interferon-beta/glatiramer acetate suggests a beneficial effect on progression to irreversible disability and rate of relapses, but not on transition to SPMS.

Should We Use Clinical Tools to Identify Disease Progression?

The presence of disability progression in multiple sclerosis (MS) is an important hallmark for MS patients in the course of their disease. The transition from relapsing remitting (RRMS) to secondary progressive forms of the disease (SPMS) represents a significant change in their quality of life and perception of the disease. It could also be a therapeutic key for opportunities, where approaches different from those in the initial phases of the disease can be adopted. The characterization of structural biomarkers (e.g., magnetic resonance imaging or neurofilament light chain) has been proposed to differentiate between both phenotypes. However, there is no definite threshold between them. Whether the risk of clinical progression can be predicted by structural markers at early disease phases is still a focus of clinical research. However, several theories and pathological evidence suggest that both disease phenotypes are part of a continuum with common pathophysiological mechanisms. In this case, the clinical evaluation of the patients would play a preponderant role above destruction biomarkers for the early identification of disability progression and SPMS. For this purpose, the use of clinical tools beyond the Expanded Disability Status Scale (EDSS) should be considered. Besides established functional tests such as the Multiple Sclerosis Functional Composite (MSFC), patient's neurological history or digital resources may help neurologists in the decision-taking. In this article, we discuss arguments for the use of clinical markers in the detection of secondary progressive MS and the characterization of progressive disease activity.

Proportion of alemtuzumab-treated patients converting from relapsing-remitting multiple sclerosis to secondary progressive multiple sclerosis over 6 years

Background

Few data exist concerning conversion to secondary progressive MS in patients treated with disease-modifying therapies.

Objective

Determine the proportion of alemtuzumab-treated patients converting from relapsing-remitting to secondary progressive MS during the CARE-MS core and extension studies.

Methods

Patients (N = 811) were analyzed post hoc for secondary progressive MS conversion. Optimal conversion definition: Expanded Disability Status Scale (EDSS) score ≥4, pyramidal functional system score ≥2, and confirmed progression over ≥3 months including confirmation within the functional system leading to progression, independent of relapse.

Results

Over 6.2 years median follow-up, 20 alemtuzumab-treated patients converted (Kaplan-Meier estimate, 2.7%; 95% confidence interval, 1.8%-4.2%). Sensitivity analysis accounting for dropouts showed similar results (3%), as did analyses using alternative definitions with different EDSS thresholds and/or confirmation periods, and analysis of core study subcutaneous interferon beta-1a-treated patients who received alemtuzumab in the extension. Patients converting to secondary progressive MS were older, and had higher EDSS scores and greater brain lesion volumes at baseline, but did not need additional alemtuzumab or other therapies.

Conclusions

The 6-year conversion rate to secondary progressive MS was low for alemtuzumab-treated patients, supporting further study of the role alemtuzumab may play in reducing risk of secondary progression.ClinicalTrials.gov identifiers: NCT00530348, NCT00548405, NCT00930553.

Transcription cofactor GRIP1 differentially affects myeloid cell-driven neuroinflammation and response to IFN-β therapy

Macrophages (MФ) and microglia (MG) are critical in the pathogenesis of multiple sclerosis (MS) and its mouse model, experimental autoimmune encephalomyelitis (EAE). Glucocorticoids (GCs) and interferon β (IFN-β) are frontline treatments for MS, and disrupting each pathway in mice aggravates EAE. Glucocorticoid receptor-interacting protein 1 (GRIP1) facilitates both GR and type I IFN transcriptional actions; hence, we evaluated the role of GRIP1 in neuroinflammation. Surprisingly, myeloid cell-specific loss of GRIP1 dramatically reduced EAE severity, immune cell infiltration of the CNS, and MG activation and demyelination specifically during the neuroinflammatory phase of the disease, yet also blunted therapeutic properties of IFN-β. MФ/MG transcriptome analyses at the bulk and single-cell levels revealed that GRIP1 deletion attenuated nuclear receptor, inflammatory and, interestingly, type I IFN pathways and promoted the persistence of a homeostatic MG signature. Together, these results uncover the multifaceted function of type I IFN in MS/EAE pathogenesis and therapy, and an unexpectedly permissive role of myeloid cell GRIP1 in neuroinflammation.

Promises and Limitations of Neural Stem Cell Therapies for Progressive Multiple Sclerosis

Multiple disease-modifying medications with regulatory approval to treat multiple sclerosis (MS) are unable to prevent inflammatory tissue damage in the central nervous system (CNS), and none directly promote repair. Thus, there is an unmet clinical need for therapies that can arrest and reverse the persistent accumulation of disabilities associated with progressive forms of MS (P-MS). Preclinical research has revealed an unexpected ability of neural stem cell (NSC) therapies to provide neurotrophic support and inhibit detrimental host immune responses in vivo following transplantation into the chronically inflamed CNS. We discuss NSC transplantation as a promising therapy for P-MS, elaborate on the necessities of clinical trial validation and formalized usage guidelines, and caution about unscrupulous 'clinics' marketing unproven therapies to patients.

The Comparison Between the Mutated HuIFN-β 27-101 and the Wild Type Interferon β: the Comprehensive In Silico Study to Evaluate the Effect of Mutations on IFN-β

Purpose: Interferon beta (IFN-β) is used to combat multiple sclerosis (MS) disease. Creating R27T and V101F mutations (mHuIFN-β-27 and mHuIFN-β-101) is one of the tasks performed to improve human interferon beta (HuIFN-β) half-life, function and expression. In this work, the impact of R27T and V101F mutations in recombinant IFN-β on its binding to interferon receptors were studied by molecular docking.

Methods: This work was performed through in silico study. The simulation of mutation was performed using the online Rosetta Backrub software and checked using server verify3D. Comparison of access to the solvent of the amino acids in the structures created was performed using the asaview online server. Also, the effect of mutations on the fold of the protein was reviewed by the online HOPE server. The molecular docking was performed between HuIFN-β and the external region of IFNAR receptor using the online ClusPro2 protein-protein docking server.

Results: The comparison of the values of the negative binding energy (ΔGbind) obtained from protein-protein molecular docking between IFNAR receptor and HuIFN-β, mHuIFN-β-27, mHuIFN-β-101 and mHuIFN-β-27-101 ligands did not show a significant difference, and these differences do not see any meaningful relationship between them (P > 0.9999).

Conclusion: Regarding these results, it can be concluded that these mutations do not have a negative effect on the composition of the complex rHuIFN-β/IFNAR. So, they do not interfere with the binding of the IFN-β to the receptor. It is concluded that the quality of the rHuIFN-β is improved by introducing these two mutations.

The long-term effects of disease modifying therapies on disability in people living with multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

Disease modifying therapies (DMT) are a common medication class for treating people living with MS. However, although treatment with DMT can extend over more than a decade, little is known about their long-term effects. Here, we systematically review long-term (≥4 years) studies on the effect of DMT on disability progression and relapse in people living with MS.

METHODS

We searched the EMBASE and Medline databases in January 2018, using search terms that included DMT and relevant outcome measures. Two authors screened all resulting studies and evaluated the risk of bias of included studies using the ROBINS-I tool for non-randomized studies. Where there was sufficient data, we performed meta-analyses using RevMan 5. Studies that could not be included in a meta-analysis were included in data synthesis.

RESULTS

Our search returned 7,766 unique articles for review. After screening, 18 articles were included. Follow-up in these studies ranged from a mean of 3.9 years to a median of 17.8 years. Fifteen (83.3%) of the included studies had a moderate risk of bias and three (16.7%) had a serious risk of bias. Meta-analysis showed that DMT significantly reduced the risk of EDSS 6.0 and SPMS compared to no treatment.

CONCLUSION

There is some evidence that long-term treatment with interferon beta reduces the risk of EDSS 6.0 and SPMS compared to no treatment or placebo. More work is needed on the effect of second generation DMT and the relative effect of DMT on health outcomes.

Risk of secondary progressive multiple sclerosis: A longitudinal study

Background:

The risk factors for conversion from relapsing-remitting to secondary progressive multiple sclerosis remain highly contested.

Objective:

The aim of this study was to determine the demographic, clinical and paraclinical features that influence the risk of conversion to secondary progressive multiple sclerosis.

Methods:

Patients with adult-onset relapsing–remitting multiple sclerosis and at least four recorded disability scores were selected from MSBase, a global observational cohort. The risk of conversion to objectively defined secondary progressive multiple sclerosis was evaluated at multiple time points per patient using multivariable marginal Cox regression models. Sensitivity analyses were performed.

Results:

A total of 15,717 patients were included in the primary analysis. Older age (hazard ratio (HR) = 1.02, p < 0.001), longer disease duration (HR = 1.01, p = 0.038), a higher Expanded Disability Status Scale score (HR = 1.30, p < 0.001), more rapid disability trajectory (HR = 2.82, p < 0.001) and greater number of relapses in the previous year (HR = 1.07, p = 0.010) were independently associated with an increased risk of secondary progressive multiple sclerosis. Improving disability (HR = 0.62, p = 0.039) and disease-modifying therapy exposure (HR = 0.71, p = 0.007) were associated with a lower risk. Recent cerebral magnetic resonance imaging activity, evidence of spinal cord lesions and oligoclonal bands in the cerebrospinal fluid were not associated with the risk of conversion.

Conclusion:

Risk of secondary progressive multiple sclerosis increases with age, duration of illness and worsening disability and decreases with improving disability. Therapy may delay the onset of secondary progression.

Association of Initial Disease-Modifying Therapy With Later Conversion to Secondary Progressive Multiple Sclerosis

IMPORTANCE

Within 2 decades of onset, 80% of untreated patients with relapsing-remitting multiple sclerosis (MS) convert to a phase of irreversible disability accrual termed secondary progressive MS. The association between disease-modifying treatments (DMTs), and this conversion has rarely been studied and never using a validated definition.

OBJECTIVE

To determine the association between the use, the type of, and the timing of DMTs with the risk of conversion to secondary progressive MS diagnosed with a validated definition.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study with prospective data from 68 neurology centers in 21 countries examining patients with relapsing-remitting MS commencing DMTs (or clinical monitoring) between 1988-2012 with minimum 4 years' follow-up.

EXPOSURES

The use, type, and timing of the following DMTs: interferon beta, glatiramer acetate, fingolimod, natalizumab, or alemtuzumab. After propensity-score matching, 1555 patients were included (last follow-up, February 14, 2017).

MAIN OUTCOME AND MEASURE

Conversion to objectively defined secondary progressive MS.

RESULTS

Of the 1555 patients, 1123 were female (mean baseline age, 35 years [SD, 10]). Patients initially treated with glatiramer acetate or interferon beta had a lower hazard of conversion to secondary progressive MS than matched untreated patients (HR, 0.71; 95% CI, 0.61-0.81; P < .001; 5-year absolute risk, 12% [49 of 407] vs 27% [58 of 213]; median follow-up, 7.6 years [IQR, 5.8-9.6]), as did fingolimod (HR, 0.37; 95% CI, 0.22-0.62; P < .001; 5-year absolute risk, 7% [6 of 85] vs 32% [56 of 174]; median follow-up, 4.5 years [IQR, 4.3-5.1]); natalizumab (HR, 0.61; 95% CI, 0.43-0.86; P = .005; 5-year absolute risk, 19% [16 of 82] vs 38% [62 of 164]; median follow-up, 4.9 years [IQR, 4.4-5.8]); and alemtuzumab (HR, 0.52; 95% CI, 0.32-0.85; P = .009; 5-year absolute risk, 10% [4 of 44] vs 25% [23 of 92]; median follow-up, 7.4 years [IQR, 6.0-8.6]). Initial treatment with fingolimod, alemtuzumab, or natalizumab was associated with a lower risk of conversion than initial treatment with glatiramer acetate or interferon beta (HR, 0.66; 95% CI, 0.44-0.99; P = .046); 5-year absolute risk, 7% [16 of 235] vs 12% [46 of 380]; median follow-up, 5.8 years [IQR, 4.7-8.0]). The probability of conversion was lower when glatiramer acetate or interferon beta was started within 5 years of disease onset vs later (HR, 0.77; 95% CI, 0.61-0.98; P = .03; 5-year absolute risk, 3% [4 of 120] vs 6% [2 of 38]; median follow-up, 13.4 years [IQR, 11-18.1]). When glatiramer acetate or interferon beta were escalated to fingolimod, alemtuzumab, or natalizumab within 5 years vs later, the HR was 0.76 (95% CI, 0.66-0.88; P < .001; 5-year absolute risk, 8% [25 of 307] vs 14% [46 of 331], median follow-up, 5.3 years [IQR], 4.6-6.1).

CONCLUSIONS AND RELEVANCE

Among patients with relapsing-remitting MS, initial treatment with fingolimod, alemtuzumab, or natalizumab was associated with a lower risk of conversion to secondary progressive MS vs initial treatment with glatiramer acetate or interferon beta. These findings, considered along with these therapies' risks, may help inform decisions about DMT selection.

Predicting risk of secondary progression in multiple sclerosis: A nomogram

OBJECTIVES

We aimed at designing a nomogram, a prediction tool, to predict the individual's risk of conversion to secondary progressive multiple sclerosis (SPMS) at the time of multiple sclerosis (MS) onset.

METHODS

One derivation and three validation cohorts were established. The derivation cohort included 8825 relapsing-onset MS patients in Sweden. A nomogram was built based on a survival model with the best statistical fit and prediction accuracy. The nomogram was validated using data from 3967 patients in the British Columbia cohort, 176 patients in the ACROSS and 2355 patients in FREEDOMS/FREEDOMS II extension studies.

RESULTS

Sex, calendar year of birth, first-recorded Expanded Disability Status Scale (EDSS) score, age at the first EDSS and age at disease onset showed significant predictive ability to estimate the risk of SPMS conversion at 10, 15 and 20 years. The nomogram reached 84% (95% confidence intervals (CIs): 83-85) internal and 77% (95% CI: 76-78), 77% (95% CI: 70-85) and 87% (95% CI: 84-89) external accuracy.

CONCLUSIONS

The SPMS nomogram represents a much-needed complementary tool designed to assist in decision-making and patient counselling in the early phase of MS. The SPMS nomogram may improve outcomes by prompting timely and more efficacious treatment for those with a worse prognosis.

Fractional anisotropy of white matter, disability and blood iron parameters in multiple sclerosis

Multiple sclerosis (MS) is a disorder related to myelin damage, which can be investigated by neuroimaging techniques such as fractional anisotropy (FA), a measure of microstructural white matter properties. The objectives of this study were to investigate (1) the relationship between FA and disability using an extremes of outcome approach, and (2) whether blood iron parameters were associated with FA and/or disability. Patients diagnosed with MS (n = 107; 14 males and 93 females) had iron parameter tests and disability determinations using the Expanded Disability Status Scale (EDSS). FA was recorded in 48 white matter tracts in 11 of the female patients with MS and 12 female controls.

RESULTS

In patients with high disability scores the mean FA was significantly lower (0.34 ± 0.067) than in the control group (0.45 ± 0.036; p = 0.04), while patients with low disability had mean FA values (0.44 ± 0.014) similar to controls (p = 0.5). Positive associations were found between FA and the iron parameters serum iron, ferritin and percentage transferrin saturation (%Tfsat) in all the white matter tracts. For % Tfsat, the associations were highly significant in 14 tracts (p < 0.01; r-values 0.74-0.84) and p < 0.001 (r = 0.83) in the superior fronto occipital fasciculus (LH). In the whole patient group a trend was found towards an inverse association between the EDSS and the %Tfsat (r = -0.26, p = 0.05) after excluding male gender and smoking as confounders, suggesting reduced disability in the presence of higher blood iron parameters. Additionally, significant inverse associations between disease duration and haemoglobin (p = 0.04) as well as %Tfsat (p = 0.02) suggested that patients with MS may experience a decrease in blood iron concentrations over time.

A 8-year retrospective cohort study comparing Interferon-β formulations for relapsing-remitting multiple sclerosis

BACKGROUND

Interferon-β has been approved for the treatment of relapsing-remitting (RR) multiple sclerosis (MS), whereas its efficacy in preventing long-term disability and conversion to secondary progressive (SP) MS is still debated. We aim to compare long-term clinical evolution of newly-diagnosed RRMS patients treated with different Interferon-β formulations.

METHODS

507 patients were included in the analysis and followed-up for 8.5 ± 3.9 years. 37.6% were treated with subcutaneous Interferon-β1a 44mcg, 33.4% with intramuscular Interferon-β1a 30mcg, and 29.0% with subcutaneous Interferon-β1b 250mcg. Relapse occurrence, 1-point EDSS progression, reaching of EDSS 4.0 and conversion to SP were recorded as outcome measures. To reduce the selection bias, we calculated the propensity score of receiving the specific treatment considering age (32.7 ± 8.3 years), gender (female 63.1%), disease duration (2.7 ± 2.8 years), and baseline EDSS (1.5, range 1.0-3.5). Propensity score and covariates (age, gender, disease duration and EDSS) were included in the statistical models.

RESULTS

At Cox regression models, the reaching of EDSS 4.0 was not-significantly higher for Interferon-β1b 250mcg (HR = 1.207; p = 0.063) and for Interferon-β1a 30mcg (HR = 1.363; p = 0.095), when compared with Interferon-β1a 44mcg. The rate of SP conversion was higher for Interferon-β1b 250mcg (HR = 2.054; p = 0.042), and not-significantly higher for Interferon-β1a 30mcg (HR = 1.884; p = 0.081), when compared with Interferon-β1a 44mcg.

CONCLUSIONS

Patients treated with Interferon-β1a 44mcg presented with a marginally reduced risk of disability accrual in the long-term, when compared with Interferon-β1b 250mcg and, at least in part, with Interferon-β1a 30mcg. Formulation, frequency of administration and dose of Interferon-β might affect the long-term clinical evolution of RRMS.

Estimating inverse probability weights using super learner when weight-model specification is unknown in a marginal structural Cox model context

Correct specification of the inverse probability weighting (IPW) model is necessary for consistent inference from a marginal structural Cox model (MSCM). In practical applications, researchers are typically unaware of the true specification of the weight model. Nonetheless, IPWs are commonly estimated using parametric models, such as the main-effects logistic regression model. In practice, assumptions underlying such models may not hold and data-adaptive statistical learning methods may provide an alternative. Many candidate statistical learning approaches are available in the literature. However, the optimal approach for a given dataset is impossible to predict. Super learner (SL) has been proposed as a tool for selecting an optimal learner from a set of candidates using cross-validation. In this study, we evaluate the usefulness of a SL in estimating IPW in four different MSCM simulation scenarios, in which we varied the specification of the true weight model specification (linear and/or additive). Our simulations show that, in the presence of weight model misspecification, with a rich and diverse set of candidate algorithms, SL can generally offer a better alternative to the commonly used statistical learning approaches in terms of MSE as well as the coverage probabilities of the estimated effect in an MSCM. The findings from the simulation studies guided the application of the MSCM in a multiple sclerosis cohort from British Columbia, Canada (1995-2008), to estimate the impact of beta-interferon treatment in delaying disability progression. Copyright © 2017 John Wiley & Sons, Ltd.

Comparison of statistical approaches dealing with time-dependent confounding in drug effectiveness studies

In longitudinal studies, if the time-dependent covariates are affected by the past treatment, time-dependent confounding may be present. For a time-to-event response, marginal structural Cox models are frequently used to deal with such confounding. To avoid some of the problems of fitting marginal structural Cox model, the sequential Cox approach has been suggested as an alternative. Although the estimation mechanisms are different, both approaches claim to estimate the causal effect of treatment by appropriately adjusting for time-dependent confounding. We carry out simulation studies to assess the suitability of the sequential Cox approach for analyzing time-to-event data in the presence of a time-dependent covariate that may or may not be a time-dependent confounder. Results from these simulations revealed that the sequential Cox approach is not as effective as marginal structural Cox model in addressing the time-dependent confounding. The sequential Cox approach was also found to be inadequate in the presence of a time-dependent covariate. We propose a modified version of the sequential Cox approach that correctly estimates the treatment effect in both of the above scenarios. All approaches are applied to investigate the impact of beta-interferon treatment in delaying disability progression in the British Columbia Multiple Sclerosis cohort (1995-2008).

Comparison of Statistical Approaches for Dealing With Immortal Time Bias in Drug Effectiveness Studies

In time-to-event analyses of observational studies of drug effectiveness, incorrect handling of the period between cohort entry and first treatment exposure during follow-up may result in immortal time bias. This bias can be eliminated by acknowledging a change in treatment exposure status with time-dependent analyses, such as fitting a time-dependent Cox model. The prescription time-distribution matching (PTDM) method has been proposed as a simpler approach for controlling immortal time bias. Using simulation studies and theoretical quantification of bias, we compared the performance of the PTDM approach with that of the time-dependent Cox model in the presence of immortal time. Both assessments revealed that the PTDM approach did not adequately address immortal time bias. Based on our simulation results, another recently proposed observational data analysis technique, the sequential Cox approach, was found to be more useful than the PTDM approach (Cox: bias = -0.002, mean squared error = 0.025; PTDM: bias = -1.411, mean squared error = 2.011). We applied these approaches to investigate the association of β-interferon treatment with delaying disability progression in a multiple sclerosis cohort in British Columbia, Canada (Long-Term Benefits and Adverse Effects of Beta-Interferon for Multiple Sclerosis (BeAMS) Study, 1995-2008).

Brain health: time matters in multiple sclerosis

INTRODUCTION

We present international consensus recommendations for improving diagnosis, management and treatment access in multiple sclerosis (MS). Our vision is that these will be used widely among those committed to creating a better future for people with MS and their families.

METHODS

Structured discussions and literature searches conducted in 2015 examined the personal and economic impact of MS, current practice in diagnosis, treatment and management, definitions of disease activity and barriers to accessing disease-modifying therapies (DMTs).

RESULTS

Delays often occur before a person with symptoms suggestive of MS sees a neurologist. Campaigns to raise awareness of MS are needed, as are initiatives to improve access to MS healthcare professionals and services. We recommend a clear treatment goal: to maximize neurological reserve, cognitive function and physical function by reducing disease activity. Treatment should start early, with DMT and lifestyle measures. All parameters that predict relapses and disability progression should be included in the definition of disease activity and monitored regularly when practical. On suboptimal control of disease activity, switching to a DMT with a different mechanism of action should be considered. A shared decision-making process that embodies dialogue and considers all appropriate DMTs should be implemented. Monitoring data should be recorded formally in registries to generate real-world evidence. In many jurisdictions, access to DMTs is limited. To improve treatment access the relevant bodies should consider all costs to all parties when conducting economic evaluations and encourage the continuing investigation, development and use of cost-effective therapeutic strategies and alternative financing models.

CONCLUSIONS

The consensus findings of an international author group recommend a therapeutic strategy based on proactive monitoring and shared decision-making in MS. Early diagnosis and improved treatment access are also key components.

Association between the use of selective serotonin reuptake inhibitors and multiple sclerosis disability progression

BACKGROUND

Benefits of selective serotonin reuptake inhibitors (SSRIs) in modifying the multiple sclerosis (MS) disease course have been suggested, but their ability to delay disability progression remains unknown. We examined the association between SSRI exposure and MS disability progression.

METHODS

A nested case-control study was conducted using the British Columbia (Canada) Multiple Sclerosis clinical data linked to health administrative data. The primary outcome was a sustained score of 6 (requires a cane to walk) on the Expanded Disability Status Scale (EDSS), and the secondary outcome was the onset of secondary progressive MS (SPMS, an advanced stage of MS). The cases were those who reached a study outcome and were matched with up to four randomly selected controls by sex, age, EDSS and calendar year at study entry using incidence density sampling. The associations between disability worsening and SSRI exposure were assessed with conditional logistic regression models, adjusted for confounders.

RESULTS

A total of 3920 patients were included in the main analyses, of which 272 reached sustained EDSS 6 and 187 reached SPMS. SSRI exposure was significantly different between patients who reached sustained EDSS 6 and controls [adjusted odds ratio (adjOR):1.44; 95% confidence interval (CI):1.03-2.01]. However, SSRI exposure was not significantly different between those who reached SPMS and their controls (adjOR:1.35; 95%CI:0.89-2.04).

CONCLUSION

We found no evidence to suggest that SSRI exposure was associated with a delay in MS disability accumulation or progression. Copyright © 2016 John Wiley & Sons, Ltd.

From genetic associations to functional studies in multiple sclerosis

Genetic screens steadily reveal more loci that show robust associations to complex human diseases, including multiple sclerosis (MS). Although some of the identified genetic variants are easily interpreted into a biological function, most of the genetic associations are frequently challenging to interpret. Underlying these difficulties is the fact that chip-based assays typically detect single nucleotide polymorphisms (SNPs) representative of a stretch of DNA containing many genomic variants in linkage disequilibrium. Furthermore, a large proportion of the SNPs with strongest association to MS are located in regions of the DNA that do not directly code for proteins. Here we discuss challenges faced by MS researchers to follow up the large-scale genetic screens that have been published over the past years in search of functional consequences of the identified MS-associated SNPs. We discuss experimental design, tools and methods that may provide the much-needed biological insights in both disease etiology and disease manifestations.

Pharmacokinetics and pharmacodynamics of MD1003 (high-dose biotin) in the treatment of progressive multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a chronic, potentially highly disabling neurological disorder. No disease-modifying treatments are approved in the progressive and not active forms of the disease.

AREAS COVERED

High doses of biotin were tested in an open-label pilot study involving 23 patients with progressive MS and reported positive results. A randomized, double-blind, placebo-controlled trial in 154 progressive MS patients confirmed the beneficial effect of MD1003 (high-dose biotin) on reversing or stabilizing disability progression, with a good safety profile. It is proposed that MD1003 in progressive MS 1) increases energy production in demyelinated axons and/or 2) enhances myelin synthesis in oligodendrocytes. Biotin is highly bioavailable; absorption and excretion are rapid. The major route of elimination is urinary excretion.

EXPERT OPINION

A high oral dose of biotin seems generally well tolerated but a few important safety concerns were identified: 1) teratogenicity in one species and 2) interference with some biotin-based laboratory immunoassays. The animal toxicity data are limited at such high doses. Further preclinical studies would be useful to address the mechanism of action of MD1003. Assessment of clinical benefit duration in responders will be also very important to set. Results of randomized, placebo-controlled trial are reassuring and provide hope for the treatment of progressive MS.