Bidirectional trans-synaptic axonal degeneration in the visual pathway in multiple sclerosis.

OBJECTIVE: To investigate the coexistence of anterograde and retrograde trans-synaptic axonal degeneration, and to explore the relationship between selective visual pathway damage and global brain involvement in longstanding multiple sclerosis (MS). METHODS: In this single-centre, cross-sectional study, patients with longstanding MS (N=222) and healthy controls (HC, N=62) were included. We analysed thickness of retinal layers (optical coherence tomography), damage within optic radiations (OR) (lesion volume and fractional anisotropy and mean diffusivity by diffusion tensor imaging) and atrophy of the visual cortex and that of grey and white matter of the whole-brain (structural MRI). Linear regression analyses were used to assess associations between the different components and for comparing patients with and without optic neuritis and HC. RESULTS: In patients with MS, an episode of optic neuritis (MSON) was significantly associated with decreased integrity of the ORs and thinning of the peripapillary retinal nerve fibre layer (pRNFL) and macular ganglion cell complex (GCC). Lesion volume in the OR was negatively associated with pRNFL and GCC thickness in patients without optic neuritis (MSNON). The pRNFL and GCC showed associations with integrity of the OR, thickness of the primary visual cortex (only in patients with MSON), and also with global white and grey matter atrophy. In HCs, no such relationships were demonstrated. INTERPRETATION: This study provides evidence for presence of bidirectional (both anterograde and retrograde) trans-synaptic axonal degeneration in the visual pathway of patients with MS. Additionally, thinning of the retinal pRNFL and GCC are related to global white and grey matter atrophy in addition to pathology of the visual pathway.

Detecting clinically-relevant changes in progressive multiple sclerosis.

OBJECTIVE: To investigate which changes in different clinical outcome measures contribute most to increased disease impact, as reported by the patient, in progressive multiple sclerosis (MS). METHODS: From a cohort of prospectively-followed MS patients, we selected progressive patients with two visits, 4-6 years apart. We assessed long-term changes on the Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT) and Guy's Neurological Disability Scale (GNDS). We defined the presence or absence of clinically meaningful change by using the Multiple Sclerosis Impact Scale (MSIS-29) as an anchor measure. We also studied change on recently identified sub-scales of GNDS. RESULTS: Change on GNDS (especially the spinal-plus subscale) contributed most to increased disease impact. Also change on the T25FW contributed largely. Specific profiles of change in T25FW and MSIS seemed to exist (generally, a lower increase in disease impact in patients with longer disease duration and higher baseline impact/disability). In some patients a dissociation existed between increased impact, according to the MSIS-29, and objective physical worsening of the T25FW. CONCLUSION: These results support using GNDS (particularly the spinal-plus domain) and T25FW in outcome measurement in progressive MS. We suggest there is a relation between baseline clinical characteristics and an increased impact at follow-up. This may have implications for patient selection in trials for progressive MS.

Application of serum natalizumab levels during plasma exchange in MS patients with progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a severe complication of natalizumab treatment. Restoring immune function by plasmapheresis/immunoadsorption (PLEX/IA) is important for the outcome of PML. We report on four multiple sclerosis (MS) patients whom developed PML during natalizumab treatment, in whom we measured serum natalizumab concentrations before and during PLEX. Depending on the serum natalizumab concentration at the time of PML diagnosis, the number of PLEX treatments necessary to reach subtherapeutic serum natalizumab concentrations is variable. Measuring serum natalizumab concentrations before and during PLEX is helpful to determine the optimum number of PLEX treatments in individual MS patients with PML.

Functional brain network analysis using minimum spanning trees in Multiple Sclerosis: an MEG source-space study.

Cognitive dysfunction in Multiple Sclerosis (MS) is closely related to altered functional brain network topology. Conventional network analyses to compare groups are hampered by differences in network size, density and suffer from normalization problems. We therefore computed the Minimum Spanning Tree (MST), a sub-graph of the original network, to counter these problems. We hypothesize that functional network changes analysed with MSTs are important for understanding cognitive changes in MS and that changes in MST topology also represent changes in the critical backbone of the original brain networks. Here, resting-state magnetoencephalography (MEG) recordings from 21 early MS patients and 17 age-, gender-, and education-matched controls were projected onto atlas-based regions-of-interest (ROIs) using beamforming. The phase lag index was applied to compute functional connectivity between regions, from which a graph and subsequently the MST was constructed. Results showed lower global integration in the alpha2 (10-13Hz) and beta (13-30Hz) bands in MS patients, whereas higher global integration was found in the theta band. Changes were most pronounced in the alpha2 band where a loss of hierarchical structure was observed, which was associated with poorer cognitive performance. Finally, the MST in MS patients as well as in healthy controls may represent the critical backbone of the original network. Together, these findings indicate that MST network analyses are able to detect network changes in MS patients, which may correspond to changes in the core of functional brain networks. Moreover, these changes, such as a loss of hierarchical structure, are related to cognitive performance in MS.

Structural degree predicts functional network connectivity: a multimodal resting-state fMRI and MEG study.

Communication between neuronal populations in the human brain is characterized by complex functional interactions across time and space. Recent studies have demonstrated that these functional interactions depend on the underlying structural connections at an aggregate level. Multiple imaging modalities can be used to investigate the relation between the structural connections between brain regions and their functional interactions at multiple timescales. We investigated if consistent modality-independent functional interactions take place between brain regions, and whether these can be accounted for by underlying structural properties. We used functional MRI (fMRI) and magnetoencephalography (MEG) recordings from a population of healthy adults together with a previously described structural network. A high overlap in resting-state functional networks was found in fMRI and especially alpha band MEG recordings. This overlap was characterized by a strongly interconnected functional core network in temporo-posterior brain regions. Anatomically realistically coupled neural mass models revealed that this strongly interconnected functional network emerges near the threshold for global synchronization. Most importantly, this functional core network could be explained by a trade-off between the product of the degrees of structurally-connected regions and the Euclidean distance between them. For both fMRI and MEG, the product of the degrees of connected regions was the most important predictor for functional network connectivity. Therefore, irrespective of the modality, these results indicate that a functional core network in the human brain is especially shaped by communication between high degree nodes of the structural network.

A dam for retrograde axonal degeneration in multiple sclerosis?

OBJECTIVE: Trans-synaptic axonal degeneration is a mechanism by which neurodegeneration can spread from a sick to a healthy neuron in the central nervous system. This study investigated to what extent trans-synaptic axonal degeneration takes place within the visual pathway in multiple sclerosis (MS). METHODS: A single-centre study, including patients with long-standing MS and healthy controls. Structural imaging of the brain (MRI) and retina (spectral-domain optical coherence tomography) were used to quantify the extent of atrophy of individual retinal layers and the primary and secondary visual cortex. Generalised estimation equations and multivariable regression analyses were used for comparisons. RESULTS: Following rigorous quality control (OSCAR-IB), data from 549 eyes of 293 subjects (230 MS, 63 healthy controls) were included. Compared with control data, there was a significant amount of atrophy of the inner retinal layers in MS following optic neuritis (ON) and also in absence of ON. For both scenarios, atrophy stopped at the level of the inner nuclear layer. In contrast, there was significant localised atrophy of the primary visual cortex and secondary visual cortex in MS following ON, but not in MS in absence of ON. INTERPRETATION: These data suggest that retrograde (trans-synaptic) axonal degeneration stops at the inner nuclear layer, a neuronal network capable of plasticity. In contrast, there seems to be no neuroplasticity of the primary visual cortex, rendering the structure vulnerable to anterograde (trans-synaptic) degeneration.

Long-term impact of interferon beta-1b in patients with CIS: 8-year follow-up of BENEFIT.

OBJECTIVE: To examine the long-term impact of early treatment initiation of interferon beta-1b (IFNB1b, Betaferon/Betaseron) in patients with a first event suggestive of multiple sclerosis (MS). METHODS: In the original placebo-controlled phase of BENEFIT, patients were randomised to IFNB1b 250 µg or placebo subcutaneously every other day. After 2 years or diagnosis of clinically definite MS (CDMS), all patients were offered open-label IFNB1b treatment for a maximum duration of 5 years. Thereafter, patients were enrolled in an observational extension study for up to 8.7 years. RESULTS: Of the initial 468 patients, 284 (60.7%; IFNB1b: 178 (61.0% of the original arm), placebo: 106 (60.2% of original arm)) were enrolled in the extension study. 94.2% of patients were receiving IFNB1b. Patients originally randomised to IFNB1b had a reduced risk of developing CDMS by 32.2% over the 8-year observation period (HR 0.678; 95% CI 0.525 to 0.875; p=0.0030), a longer median time to CDMS by 1345 days (95% CI 389 to 2301), and a lower annualised relapse rate (0.196 (95% CI 0.176 to 0.218) versus 0.255 (95% CI 0.226 to 0.287), p=0.0012), with differences mainly emerging in the first year of the study. Cognitive outcomes remained higher in the early treated patients. EDSS remained low over time with a median of 1.5 in both arms. CONCLUSIONS: These 8-year results provide further evidence supporting early initiation of treatment with IFNB1b in patients with a first event suggestive of MS.

Disease course heterogeneity and OCT in multiple sclerosis.

BACKGROUND: The heterogeneity of the disease course in multiple sclerosis (MS) remains a challenge for patient management and clinical trials. OBJECTIVE: The objective of this paper is to investigate the relationship between disease course heterogeneity and retinal layer thicknesses in MS. METHODS: A total of 230 MS patients and 63 healthy control subjects were included. Spectral-domain OCT scanning of the peripapillary and macular regions was performed, followed by automated eight-layer segmentation. Generalised estimation equations were used for comparisons. Receiver operating characteristic (ROC) curves were calculated for distinguishing a benign from a typical disease course. RESULTS: Primary progressive patients showed relative preservation of inner retinal layers, compared to the relapsing onset MS types. Only in MS eyes without optic neuritis did patients with typical MS show more severe thinning of the inner retinal layers (RNFL to INL) compared to patients with a benign disease course, even after an average disease course of 20 years. CONCLUSION: The thicknesses, particularly of the innermost retinal layers (RNFL, GCC), were significantly related to the heterogeneous disease course in MS. The relative preservation of these layers in primary progressive and benign MS suggests rather limited susceptibility of the retina to neurodegeneration, which may be relevant for future neurodegenerative treatment trials employing OCT as a secondary outcome measure in primary progressive MS.

Oxysterols and cholesterol precursors correlate to magnetic resonance imaging measures of neurodegeneration in multiple sclerosis.

BACKGROUND: Cholesterol homeostasis is important for formation and maintenance of myelin and axonal membranes in the central nervous system (CNS). The concentrations of the brain specific cholesterol metabolite 24S-hydroxycholesterol (24OHC) and cholesterol precursors have been shown to be altered in multiple sclerosis (MS). However, how changes in sterol levels relate to the pathological processes in MS is not clear. METHODS: In this study, we compared serum and cerebrospinal fluid (CSF) sterol levels between 105 MS (51 relapsing-remitting (RR); 39 secondary progressive (SP) and 15 primary progressive (PP)) and 49 control patients. Sterol levels were correlated to magnetic resonance imaging (MRI) markers of disease activity. RESULTS: We found decreased serum 24OHC and 27-hydroxycholesterol (27OHC) and increased CSF lathosterol in MS patients compared to control patients (p=0.018, p=0.002 and p=0.002, respectively). Subgroup analysis showed that serum 24OHC levels were negatively correlated to normalized brain volume measurements in relapse-onset MS patients (r= -0.326, p=0.004). CONCLUSIONS: These results confirm that cholesterol homeostasis is disturbed in MS and suggest that changes in cholesterol synthesis are related to neurodegenerative pathological processes as seen on the MRI. The data seem to be in line with the recently reported observation that high dose statins may have a positive effect on clinical disability in secondary progressive MS.

Changes in functional network centrality underlie cognitive dysfunction and physical disability in multiple sclerosis.

BACKGROUND: Cognitive dysfunction in multiple sclerosis (MS) has a large impact on the quality of life and is poorly understood. OBJECTIVE: The aim of this study was to investigate functional network integrity in MS, and relate this to cognitive dysfunction and physical disability. METHODS: Resting state fMRI scans were included of 128 MS patients and 50 controls. Eigenvector centrality mapping (ECM) was applied, a graph analysis technique that ranks the importance of brain regions based on their connectivity patterns. Significant ECM changes were related to physical disability and cognitive dysfunction. RESULTS: In MS patients, ECM values were increased in bilateral thalamus and posterior cingulate (PCC) areas, and decreased in sensorimotor and ventral stream areas. Sensorimotor ECM decreases were related to higher EDSS (rho = -0.24, p = 0.007), while ventral stream decreases were related to poorer average cognition (rho = 0.23, p = 0.009). The thalamus displayed increased connectivity to sensorimotor and ventral stream areas. CONCLUSION: In MS, areas in the ventral stream and sensorimotor cortex appear to become less central in the entire functional network of the brain, which is associated with clinico-cognitive dysfunction. The thalamus, however, displays increased connectivity with these areas. These findings may aid in further elucidating the function of functional reorganization processes in MS.

Early detection of neutralizing antibodies to interferon-beta in multiple sclerosis patients: binding antibodies predict neutralizing antibody development.

BACKGROUND: Neutralizing antibodies (NAb) affect efficacy of interferon-beta (IFN-b) treatment in multiple sclerosis (MS) patients. NAbs evolve in up to 44% of treated patients, usually between 6-18 months on therapy. OBJECTIVES: To investigate whether early binding antibody (BAb) titers or different IFN-b biomarkers predict NAb evolution. METHODS: We included patients with MS or clinically isolated syndrome (CIS) receiving de novo IFN-b treatment in this prospective European multicenter study. Blood samples were collected at baseline, before and after the first IFN-b administration, and again after 3, 12 and 24 months on that therapy; for determination of NAbs, BAbs, gene expression of MxA and protein concentrations of MMP-9, TIMP-1, sTRAIL, CXCL-10 and CCL-2. RESULTS: We found that 22 of 164 (13.4%) patients developed NAbs during a median time of 23.8 months on IFN-b treatment. Of these patients, 78.9% were BAb-positive after 3 months. BAb titers ≥ 1:2400 predicted NAb evolution with a sensitivity of 74.7% and a specificity of 98.5%. Cross-sectionally, MxA levels were significantly diminished in the BAb/NAb-positive samples; similarly, CXCL-10 and sTRAIL concentrations in BAb/NAb-positive and BAb-positive/NAb-negative samples, respectively, were also diminished compared to BAb/NAb-negative samples. CONCLUSIONS: BAb titers reliably predict NAbs. CXCL-10 is a promising sensitive biomarker for IFN-b response and its abrogation by anti-IFN-b antibodies.

Magnetic resonance imaging correlates of physical disability in relapse onset multiple sclerosis of long disease duration.

BACKGROUND: Understanding long-term disability in multiple sclerosis (MS) is a key goal of research; it is relevant to how we monitor and treat the disease. OBJECTIVES: The Magnetic Imaging in MS (MAGNIMS) collaborative group sought to determine the relationship of brain lesion load, and brain and spinal cord atrophy, with physical disability in patients with long-established MS. METHODS: Patients had a magnetic resonance imaging (MRI) scan of their brain and spinal cord, from which we determined brain grey (GMF) and white matter (WMF) fractional volumes, upper cervical spinal cord cross-sectional area (UCCA) and brain T2-lesion volume (T2LV). We assessed patient disability using the Expanded Disability Status Scale (EDSS). We analysed associations between EDSS and MRI measures, using two regression models (dividing cohort by EDSS into two and four sub-groups). RESULTS: In the binary model, UCCA (p < 0.01) and T2LV (p = 0.02) were independently associated with the requirement of a walking aid. In the four-category model UCCA (p < 0.01), T2LV (p = 0.02) and GMF (p = 0.04) were independently associated with disability. CONCLUSIONS: Long-term physical disability was independently linked with atrophy of the spinal cord and brain T2 lesion load, and less consistently, with brain grey matter atrophy. Combinations of spinal cord and brain MRI measures may be required to capture clinically-relevant information in people with MS of long disease duration.

Walking speed, rather than Expanded Disability Status Scale, relates to long-term patient-reported impact in progressive MS.

OBJECTIVE: To study the relationships between 1-2 year changes in well-known physician-rated measurements (Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT)) and the long-term (≥ 5 years) outcome in patient-reported outcome (PRO) measures (Multiple Sclerosis Impact Scale (MSIS-29), Multiple Sclerosis Walking Scale (MSWS-12)) that reflect the patient-perceived impact of disease, in progressive MS. METHODS: We selected all progressive patients having at least two complete visits within 1-2 years, from a larger cohort of prospectively-followed MS patients. These were invited for another visit, at least 5 years later, consisting of another series of similar examinations, plus 2 PRO scales: the MSIS-29 and MSWS-12. We explored associations between early changes in physician-rated measurements and the long-term outcome as per the PRO measures. RESULTS: In this study,134 patients fulfilled the selection criteria. We found that early change in T25FW was the only physician-rated change that was significantly related to long-term physical impact experienced by the patient, as was assessed by MSIS-29 (Kruskal-Wallis test: χ(2)=7.8, p=0.020). Early T25FW change, and to a lesser degree early 9HPT change, were significantly related to the reported long-term walking limitations, as assessed by MSWS-12 (Kruskal-Wallis test: χ(2)=13.8 and p=0.001 for T25FW, χ(2)=6.5 and p=0.038 for 9HPT). None of the early physician-rated changes were related to the long-term psychological impact experienced by the patient. CONCLUSION: Early changes on physician-rated scales do have long-term impact in terms of potentially predictive value of outcomes for groups of patients in progressive MS, regarding walking limitations and more global physical impact. Surprisingly, early change in T25FW, rather than early change in EDSS, was significantly associated with longer-term patient-reported disease impact. Our study data support the value of using early physician-rated examinations in clinical trials in progressive MS.

Increased plasma 8,12-iso-iPF2alpha- VI levels in relapsing multiple sclerosis patients are not predictive of disease progression.

BACKGROUND: Oxidative stress plays an important role in multiple sclerosis (MS). Isoprostanes are biomarkers for oxidative stress and have been related to neurological disease progression. OBJECTIVE: To study whether plasma isoprostane levels were related to disease progression in MS. METHODS: Plasma levels of 8,12-iso-iPF2alpha-VI were determined in 17 patients with clinically isolated syndrome (CIS), 41 relapsing-remitting MS (RRMS) patients and 5 primary progressive MS (PPMS) patients and related to MRI and clinical disease parameters. RESULTS: Isoprostane levels were similar in CIS (60.9, interquartile range (IQR): 47.7-77.7 pg/ml) and RRMS patients (65.3, IQR: 51.9-82.8 pg/ml). The plasma levels were lower in PPMS patients (42.5, IQR: 37.1-49.9) pg/ml, p<0.05) compared to CIS and RRMS patients in this cohort, which was not confirmed in a second cohort. Baseline isoprostane levels were not related to clinical progression defined by conversion form CIS to RRMS or change in Expanded Disability Status Scale (EDSS) or MS Functional Composite (MSFC) scores during six years of follow-up (CIS + RRMS), nor to change in volume of gadolinium enhancing lesions, T2 lesion load or T1 hypointense lesion load during 2.8 years of follow-up (CIS + RRMS). CONCLUSION: These results do not support a strong role of 8,12-iso-iPF2alpha-VI in the prediction of disease progression in MS.

Proxy measurements in multiple sclerosis: agreement on different patient-reported outcome scales.

BACKGROUND: Patient-reported outcome (PRO) scales are often used in multiple sclerosis (MS) research. Full understanding of items can be influenced by disease worsening, mood disturbances and cognitive problems of the MS patient. Earlier research with the Multiple Sclerosis Impact Scale (MSIS-29) showed that proxy respondents (i.e. partners of patients) can provide useful information. OBJECTIVE: To determine agreement between patients and proxy respondents on different MS PRO scales. METHODS: 139 Patients and partners completed the MSIS-29 (Physical and Psychological scale), Multiple Sclerosis Walking Scale (MSWS-12), Multiple Sclerosis Neuropsychological Screening Questionnaire (MSNQ) and Guy's Neurological Disability Scale (GNDS). We calculated the mean difference and intra-class correlation coefficients (ICC) on scale level and weighted kappas (κ(w)) on item level. RESULTS: On all scales, except MSNQ, the partner score was higher. ICCs were good for MSWS, GNDS and MSIS Physical, and moderate for MSNQ and MSIS Psychological. κ(w) was excellent for MSWS items, fair to good for GNDS, MSIS Physical and MSIS Psychological items, and poor for MSNQ items. CONCLUSION: Partners of patients with MS can be a useful source of information for several PRO scales, especially when the focus is on physical functioning. For psychological functioning this seems to be less reliable.

Predictive nature of IgM anti-α-glucose serum biomarker for relapse activity and EDSS progression in CIS patients: a BENEFIT study analysis.

BACKGROUND: Higher serum levels of at least one of a panel of four α-glucose IgM antibodies (gMS-Classifier1) in clinically isolated syndrome (CIS) patients are associated with imminent early relapse within 2 years. OBJECTIVE: The objective of this study was to determine the prognostic value of gMS-Classifier1 in a large study cohort of CIS patients. METHODS: The BEtaseron(®) in Newly Emerging multiple sclerosis For Initial Treatment (BENEFIT) 5-year study was designed to evaluate the impact of early versus delayed interferon-ß-1b (IFNß-1b; Betaseron(®)) treatment in patients with a first event suggestive of multiple sclerosis (MS). Patients (n = 258, 61% of total) with a minimum of 2 ml baseline serum were eligible for the biomarker study. gMS-Classifier1 antibodies' panel (anti-GAGA2, anti-GAGA3, anti-GAGA4 and anti-GAGA6) levels were measured blinded to clinical data. Subjects were classified as either 'positive' or 'negative' according to a classification rule. RESULTS: gMS-Classifier1 was not predictive for the time to clinically definite MS or time to MS according to the revised McDonald's criteria, but did significantly predict an increased risk for confirmed disability progression (log-rank test: p = 0.012). CONCLUSIONS: We could not confirm previous results that gMS-Classifier1 can predict early conversion to MS in CIS. However, raised titres of these antibodies may predict early disability progression in this patient population.

A knowledge-driven interaction analysis reveals potential neurodegenerative mechanism of multiple sclerosis susceptibility.

Gene-gene interactions are proposed as an important component of the genetic architecture of complex diseases, and are just beginning to be evaluated in the context of genome-wide association studies (GWAS). In addition to detecting epistasis, a benefit to interaction analysis is that it also increases power to detect weak main effects. We conducted a knowledge-driven interaction analysis of a GWAS of 931 multiple sclerosis (MS) trios to discover gene-gene interactions within established biological contexts. We identify heterogeneous signals, including a gene-gene interaction between CHRM3 (muscarinic cholinergic receptor 3) and MYLK (myosin light-chain kinase) (joint P=0.0002), an interaction between two phospholipase C-ß isoforms, PLCß1 and PLCß4 (joint P=0.0098), and a modest interaction between ACTN1 (actinin alpha 1) and MYH9 (myosin heavy chain 9) (joint P=0.0326), all localized to calcium-signaled cytoskeletal regulation. Furthermore, we discover a main effect (joint P=5.2E-5) previously unidentified by single-locus analysis within another related gene, SCIN (scinderin), a calcium-binding cytoskeleton regulatory protein. This work illustrates that knowledge-driven interaction analysis of GWAS data is a feasible approach to identify new genetic effects. The results of this study are among the first gene-gene interactions and non-immune susceptibility loci for MS. Further, the implicated genes cluster within inter-related biological mechanisms that suggest a neurodegenerative component to MS.

Interferon regulatory factor 5 gene variants and pharmacological and clinical outcome of Interferonß therapy in multiple sclerosis.

Interferon-ß (IFNß) therapy is effective in approximately half of the patients with relapsing-remitting multiple sclerosis (RRMS). Clinical non-responders were characterized by an increased expression of IFN response genes before the start of therapy, and a lack of a pharmacologically induced increase in IFN response gene activity. Because Interferon Regulatory Factor 5 (IRF5) is a master regulator of IFN-activity, we carried out a candidate gene study of IRF5 gene variants in relation to the pharmacological and clinical response upon IFNß treatment. We found that patients with the IRF5 rs2004640-TT and rs47281420-AA genotype exerted a poor pharmacological response to IFNß compared with patients carrying the respective G-alleles (P=0.0006 and P=0.0023, respectively). Moreover, patients with the rs2004640-TT genotype developed more magnetic resonance imaging (MRI)-based T2 lesions during IFNß treatment (P=0.003). Accordingly, an association between MRI-based non-responder status and rs2004640-TT genotype was observed (P=0.010). For the rs4728142-AA genotype a trend of an association with more T2 lesions during IFNß treatment and MRI-based non-responder status was observed (P=0.103 and P=0.154, respectively). The clinical relevance of the rs2004640-TT genotype was validated in an independent cohort wherein a shorter time to first relapse was found (P=0.037). These findings suggest a role for IRF5 gene variation in the pharmacological and clinical outcome of IFNß therapy that might have relevance as biomarker to predict the response to IFNß in multiple sclerosis.

Disease progression in multiple sclerosis: combining physicians' and patients' perspectives?

BACKGROUND: To assess disease progression in multiple sclerosis (MS) several outcome measures are available. The interrelation of changes on different scales has not been studied extensively and the concept of combining scales has only recently been introduced in MS. OBJECTIVE: To explore combining different clinical outcome measures in the evaluation of disease progression in MS. METHODS: In 553 patients we studied the presence of relevant changes according to standard definitions on the Expanded Disability Status Scale (EDSS), Nine-Hole Peg Test (9HPT), Timed 25-Foot Walk (T25FW) and the Multiple Sclerosis Impact Scale (MSIS-29). We examined 'exclusive worsening' (worsening on one measure while not worsening on any other measure) and 'opposing changes' (worsening on one measure while improving on another measure). Finally, we investigated the impact of combining assessments. RESULTS: Based on the EDSS alone, 140 patients progressed. However, almost twice as many (275) showed worsening on any of the clinical outcome measures. Exclusive worsening was observed in 37 patients on the EDSS, 13 on the 9HPT, 39 on the T25FW and 44 on the MSIS physical. Of all worsened patients 76 (28%) showed opposing changes, a phenomenon predominantly observed when combining physician-based and patient-derived outcome measures. CONCLUSION: When assessing disease progression in MS, sensitivity to change can be increased by combining different outcome measures. The added value is especially present when combining measures from different perspectives. However, further research is needed to evaluate the optimal way to combine outcome measures before implementing this strategy in clinical studies.

Community walking can be assessed using a 10-metre timed walk test.

BACKGROUND: A decline in mobility is a common feature of multiple sclerosis (MS). Community walking scales are used to categorize patients in their ability to move independently. The first purpose of this study was to determine which specific gait speed corresponded with the categories of the Modified Functional Walking Categories (MFWC). The second purpose was to determine the Minimally Important Change (MIC) in absolute gait speed using the MFWC and Expanded Disability Status Scale (EDSS) as external criteria. METHOD: MS patients were measured six times in 6 years. Gait velocity was measured with the 10-metre timed walk test (10-m TWT), the severity of MS was determined with the EDSS, and community walking was assessed with the MFWC. For each category of the MFWC, Receiver Operating Characteristic (ROC) curves were used to find the best possible cut-off point on the 10-m TWT. The MIC in absolute gait speed was determined using a change of one category on the MFWC or one point on the EDSS. RESULTS: A strong relationship was found between gait speed and the MFWC; all areas under the ROC curves (AUCs) were between 0.74 and 0.86. The MIC in absolute gait speed could not be determined, because the AUCs were below the threshold of 0.70 and changes in gait speed were small. CONCLUSIONS: Gait speed is related to community walking, but an MIC in absolute gait speed could not be determined using a minimally important change on the MFWC or the EDSS as external criteria.