The association of selected multiple sclerosis symptoms with disability and quality of life: a large Danish self-report survey.

BACKGROUND: People with multiple sclerosis (MS) experience a wide range of unpredictable and variable symptoms. The symptomatology of MS has previously been reported in large sample registry studies; however, some symptoms may be underreported in registries based on clinician-reported outcomes and how the symptoms are associated with quality of life (QoL) are often not addressed. The aim of this study was to comprehensively evaluate the frequency of selected MS related symptoms and their associations with disability and QoL in a large self-report study. METHODS: We conducted a cross-sectional questionnaire survey among all patients at the Danish Multiple Sclerosis Center, Copenhagen University Hospital, Denmark. The questionnaire included information on clinical and sociodemographic characteristics, descriptors of QoL and disability, as well as prevalence and severity of the following MS symptoms: impaired ambulation, spasticity, chronic pain, fatigue, bowel and bladder dysfunction, and sleep disturbances. RESULTS: Questionnaires were returned by 2244/3606 (62%). Participants without MS diagnosis or incomplete questionnaires were excluded, n = 235. A total of 2009 questionnaires were included for analysis (mean age 49.4 years; mean disease duration 11.7 years; and 69% were women). The most frequently reported symptoms were bowel and bladder dysfunction (74%), fatigue (66%), sleep disturbances (59%), spasticity (51%) and impaired ambulation (38%). With exception of fatigue and sleep disturbances, all other symptoms increased in severity with higher disability level. Invisible symptoms (also referred to as hidden symptoms) such as fatigue, pain and sleep disturbances had the strongest associations with the overall QoL. CONCLUSION: We found invisible symptoms highly prevalent, even at mild disability levels. Fatigue, pain and sleep disturbances had the strongest associations with the overall QoL and were more frequently reported in our study compared with previous registry-based studies. These symptoms may be underreported in registries based on clinician reported outcomes, which emphasizes the importance of including standardized patient reported outcomes in nationwide registries to better understand the impact of the symptom burden in MS.

Circulating levels of tight junction proteins in multiple sclerosis: Association with inflammation and disease activity before and after disease modifying therapy.

BACKGROUND: Tight junction proteins contribute to maintenance of epithelial and endothelial barriers such as the intestinal barrier and the blood brain barrier (BBB). Increased permeability of these barriers has been linked to disease activity in MS and there is currently a lack of easily accessible biomarkers predicting disease activity in MS. AIM: To investigate whether levels of circulating tight junction proteins occludin and zonula occludens-1 (ZO-1) are associated with biomarkers of inflammation and disease activity; and to determine whether they could serve as clinical biomarkers. METHODS: We prospectively included 72 newly diagnosed patients with relapsing remitting MS or clinically isolated syndrome with no prior disease modifying therapy (DMT) use and 50 healthy controls (HCs). Patients were followed with blood samples, 3 tesla MRI, and clinical evaluation for 12 months. Occludin, ZO-1, calprotectin and soluble urokinase-type plasminogen activator receptor (suPAR) were measured by ELISA; serum neurofilament light (NfL) and IL-6 by single-molecule array (SIMOA). The mRNA expression of IFNG, IL1R1, IL10, IL1B, ARG1 and TNF was measured by quantitative real time polymerase chain reaction (qPCR) in whole blood. RESULTS: Plasma occludin levels were higher in MS patients compared with HCs. After 12 months on DMT, occludin levels were reduced by approximately 25% irrespective of 1st or 2nd line DMT (p<0.001). Furthermore, NfL and calprotectin levels were significantly reduced by 31% and 29%, respectively. Occludin and ZO-1 did not correlate with biomarkers of inflammation and did not predict disease activity at baseline or after 12 months. CONCLUSIONS: Higher levels of occludin suggest an increased permeability of the BBB and/or the intestinal barrier in MS patients. The reduction of occludin after 12 months on DMTs might reflect repair of these barriers upon treatment. However, plasma levels of ZO-1 and occludin could not predict clinical or MRI disease activity as determined by regression and ROC-curve analysis. Our results do not indicate a clear clinically relevant role for circulating tight junction proteins as biomarkers of disease activity in MS and further investigations in larger cohorts are needed to clarify this issue.

Biomarkers of inflammation and epithelial barrier function in multiple sclerosis.

BACKGROUND: There is a lack of reliable biomarkers predicting disability and disease activity in multiple sclerosis (MS). Recent evidence suggests an involvement of intestinal and pulmonary epithelial barrier function related to immune activation and the pathophysiology of MS. Blood biomarkers of epithelial barrier function have, however, not been widely studied in MS. OBJECTIVE: To examine biomarkers of inflammation and epithelial barrier function in relapsing remitting MS (RRMS) patients compared with healthy controls (HCs), and to assess associations between biomarkers and disease activity. METHODS: A panel of 30 biomarkers were measured in serum or plasma from 49 newly diagnosed, untreated RRMS patients and 58 HCs with electrochemiluminescence or ELISA. Neurofilament light chain (NfL) was measured with single-molecule array. Validation was performed in a second independent cohort of 68 newly diagnosed, treatment naive RRMS patients and 50 HCs. Patients were divided into groups of active and inactive disease based on NfL levels and the presence of gadolinium enhancing magnetic resonance imaging lesions. RESULTS: Patients with active MS showed significantly higher serum levels of calprotectin and soluble urokinase plasminogen activator receptor compared with inactive MS in the exploratory cohort. Validation confirmed higher levels of calprotectin in active compared with inactive MS, and HCs. Biomarkers of intestinal and pulmonary epithelial barrier function did not differ significantly between groups. CONCLUSIONS: The measured biomarkers of epithelial barrier function do not seem to play a major role in the pathophysiology of MS, but serum calprotectin could represent a clinically useful biomarker of innate immune activation and disease activity.

Expression of melanoma cell adhesion molecule-1 (MCAM-1) in natalizumab-treated multiple sclerosis.

The objectives were to study the expression of very late antigen (VLA)-4, melanoma cell adhesion molecule-1 (MCAM-1) and activated leukocyte cell adhesion molecule (ALCAM) on CD4+ T cells during natalizumab treatment and to investigate the association with disease activity. We find that subgroups of autoreactive T cells are retained in peripheral blood, in particular MOG-reactive CD4+ T cells expressing MCAM-1. The expression of MCAM-1 or ALCAM on CD4+ T cells was, however, not clearly associated with disease activity (clinical or MRI) during natalizumab treatment. We confirm upregulation of MCAM-1 on CD4+ T cells during natalizumab treatment while VLA-4 is downregulated.

Illegal cannabis use is common among Danes with multiple sclerosis.

BACKGROUND: Use of cannabis to alleviate multiple sclerosis (MS)-related symptoms is increasing. Due to strict regulations, only a minority of MS patients receive cannabis-based prescription drugs. The extent of recreational and medical cannabis use among Danes with MS is unknown. Our aim was to evaluate the prevalence of illegal and legal use of cannabis in MS patients, as well as reasons for use and perceived adverse effects. METHODS: An anonymous questionnaire was sent to all 3606 patients at the Danish Multiple Sclerosis Center, Rigshospitalet, University of Copenhagen. The questionnaire included questions about sociodemographic factors, clinical characteristics and medical or recreational cannabis use. RESULTS: Questionnaires were completed by 2244/3606 (62%), of which 2009 questionnaires from patients with MS or clinical isolated syndrome (CIS) were valid for analysis. Forty-nine percent (980/2009) had used cannabis at least once. Cannabis was used within the past year (current user) by 21%, and only 21% of those received prescribed cannabis-based medicine. Recreational use was reported by 17%. The primary reasons for use were to alleviate pain (61%), spasticity (52%) and sleep disturbances (46%). The most common adverse effects were drowsiness (30%), feeling quiet/subdued (23%) and dizziness (13%). Almost half (44%) of the non-cannabis users would consider use of cannabis to alleviate MS symptoms if the drug was legalized. CONCLUSION: This study shows that illegal cannabis use is common among Danes with MS as only 21% of the current cannabis users received prescribed cannabis-based medicine. Current cannabis users reported high efficacy in relieving pain, spasticity and sleep disturbances. In addition, only mild to moderate severity of adverse effects were reported. To the best of our knowledge, this is the most comprehensive survey of cannabis use among MS patients.

The neutrophil-to-lymphocyte ratio is associated with multiple sclerosis.

BACKGROUND: Subtypes of white blood cell counts are known biomarkers of systemic inflammation and a high neutrophil-to-lymphocyte ratio (NLR) has been associated with several autoimmune diseases. Few studies have investigated the NLR in multiple sclerosis (MS). OBJECTIVE: To examine the association between NLR, MS and disability measured by the MS severity score (MSSS). METHODS: Patients were included from the Danish Multiple Sclerosis Biobank. Information on patient NLR was obtained just before their first treatment and clinical information was provided by the Danish Multiple Sclerosis Treatment Register. Information on NLR from controls was collected from the Danish Blood Donor Study. Patients and controls were 1:2 propensity score matched by baseline confounders. RESULTS: Propensity score matching left 740 of 743 MS patients and 1420 of 4691 controls for further analyses. Odds-ratio (OR) was 3.64 (95% confidence interval 2.87-4.60, p < 0.001) for MS disease per unit increase of logarithmically transformed NLR (ln-NLR), corresponding to an OR of 2.68 for each doubling of NLR. Mean NLR was 2.12 for patients and 1.72 for controls (p < 0.001). Ln-NLR correlated weakly with patient MSSS (R 2 = 0.019, p = 0.008). CONCLUSION: Patients with early MS had increased levels of NLR compared to healthy controls and NLR was weakly correlated with MSSS.

Bone microarchitecture and bone mineral density in multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) patients are at increased risk of reduced bone mineral density (BMD) and fractures. The aetiology of bone loss in MS is unclear. Trabecular bone score (TBS) is a novel analytical tool that provides a measurement of the bone microarchitecture. Decreased TBS predicts increased fracture risk independently of BMD. To date, no studies have investigated TBS in MS patients. OBJECTIVES: To assess bone quality in MS patients by TBS and to evaluate potential risk factors that may affect BMD and TBS in patients with MS. METHODS: Two hundred sixty MS patients were included. TBS was calculated using TBS iNsight software (MediMaps® ). Multivariable regression analyses were performed with information on smoking, alcohol, glucocorticoid (GC) treatment, sun exposure, physical activity, vitamin D and BMI. RESULTS: Trabecular bone score was not significantly different from an age-matched reference population. Low TBS was associated with high age (P = .014) and smoking (P = .03). Smoking and physical inactivity were associated with low BMD in spine (P = .034, P = .032). GC treatment was not associated with TBS. CONCLUSION: We could not find altered TBS values among MS patients, suggesting that BMD alone, and not the bone microarchitecture, is affected in MS. However, larger studies are needed to verify these findings and to establish the role of TBS in MS. As in the background population, physical activity and non-smoking habits are associated with better bone health in MS.

Early safety and efficacy of fingolimod treatment in Denmark.

BACKGROUND: Initiation of fingolimod treatment is associated with a transient decrease of heart rate, and atrioventricular (AV) conduction block may occur. OBJECTIVE: To evaluate the therapeutic effect and safety of fingolimod treatment in MS patients in Denmark with focus on cardiac and pulmonary side effects at treatment onset. MATERIALS & METHODS: We analysed data from the first 496 fingolimod-treated Danish patients, observed for at least 3 months. In a subset of 204 patients, we monitored cardiac and pulmonary adverse effects following treatment initiation. RESULTS: The overall annualized relapse rate (ARR) was 0.37 (95% CI 0.31-0.44); 0.22 (95% CI 0.03-0.81) in de novo-treated patients, 0.29 (95% CI; 0.23-0.37) in patients switching from IFN-beta or GA and 0.46 (9 5% CI 0.34-0.60) after natalizumab. In the subset of 204 patients, 8 (3.9%) required prolonged cardiac monitoring due to bradycardia and/or second-degree AV block type I. All patients recovered spontaneously. Two patients discontinued fingolimod. Eleven (5.4%) patients reported respiratory complaints and two of these patients discontinued treatment. CONCLUSIONS: Fingolimod appears to be safe and effective in MS patients in a clinical setting. Mild cardiac adverse effects occurred at a similar rate as in clinical trials.

Soluble serum VCAM-1, whole blood mRNA expression and treatment response in natalizumab-treated multiple sclerosis.

BACKGROUND: Natalizumab reduces disease activity in multiple sclerosis (MS). Natalizumab binds to the very late antigen-4 and inhibits vascular cell adhesion molecule-1 (VCAM-1)-mediated transmigration of immune cells across the blood-brain-barrier. This is associated with decreased serum concentrations of soluble (s)VCAM-1 and an altered composition of immune cell-subsets in the blood. OBJECTIVE: We aimed to examine if sVCAM-1 serum concentrations and whole blood mRNA expression levels of immune activation biomarkers is associated with disease activity in natalizumab-treated MS-patients. METHODS: sVCAM-1 serum concentrations and whole blood mRNA expression were measured in blood samples from untreated RRMS-patients and from two independent groups of natalizumab-treated patients. RESULTS: sVCAM-1 serum concentrations and whole blood expression of HLX1 and IL1B mRNA were lower, whereas expression of EBI3 mRNA was higher in natalizumab-treated MS-patients. Five genes were differentially expressed in clinically unstable natalizumab-treated MS-patients in the discovery but not in the validation group. CONCLUSION: Decreased serum concentrations of sVCAM-1 and altered whole blood mRNA expression levels of a panel of immunomarkers, associated with natalizumab-treatment, are not sensitive markers of MS disease activity. However, decreased expression of pro-inflammatory HLX1 and IL1B and increased expression of immunoregulatory EBI3 may indicate a less pathogenic immune activation status in natalizumab-treated MS.

Shift work at young age is associated with increased risk of multiple sclerosis in a Danish population.

BACKGROUND: Epidemiological studies suggest an important role for environmental factors in developing multiple sclerosis (MS). Furthermore several studies have indicated that the effect of environmental factors may be especially pronounced in adolescents. Recently only one study investigated and found that shift work at young age is associated with an increased risk of developing MS. In this study we focused on the effect of shift work in the vulnerable period between 15-19 years. OBJECTIVE: The aim of this study was to investigate the association between shift work at young age and the risk of developing MS. METHODS: We performed a large case-control study including 1723 patients diagnosed with MS and 4067 controls. MS patients were recruited from the Danish Multiple Sclerosis Biobank and controls from The Danish Blood Donor Study. Information on working patterns and lifestyle factors was obtained using a comprehensive lifestyle-environmental factor questionnaire with participants enrolled between 2009 and 2014. Logistic regression models were used to investigate the association between shift work at age 15-19 years and the subsequent risk of MS and were controlled for effects due to established MS risk factors. RESULTS: We found a statistically significant association when total numbers of night shifts were compared with non-shift workers. For every additional 100 night shifts the odds ratio (OR) for MS was 1.20 (95% confidence interval (CI), 1.08-1.34, p=0.001). Increasing intensity of shift work also increased MS risk. For every additional night per month the OR was 1.04 (95% CI, 1.01-1.06, p=0.002). Duration of shift work in years was not associated with risk of MS. CONCLUSION: This study supports a statistically significant association between shift work at age 15-19 years and MS risk.

Short-term, high-dose glucocorticoid treatment does not contribute to reduced bone mineral density in patients with multiple sclerosis.

BACKGROUND: Patients with multiple sclerosis (MS) are at increased risk of reduced bone mineral density (BMD). A contributing factor might be treatment with high-dose glucocorticoids (GCs). OBJECTIVES: The objective of this paper is to assess bone mass in patients with MS and evaluate the importance of short-term, high-dose GC treatment and other risk factors that affect BMD in patients with MS. METHODS: A total of 260 patients with MS received short-term high-dose GC treatment and had their BMD measured by dual x-ray absorptiometry. BMD was compared to a healthy age-matched reference population (Z-scores). Data regarding GCs, age, body mass index (BMI), serum 25(OH)D, disease duration and severity were collected retrospectively and analysed in a multiple linear regression analysis to evaluate the association between each risk factor and BMD. RESULTS: Osteopenia was present in 38% and osteoporosis in 7% of the study population. Mean Z-score was significantly below zero, indicating a decreased BMD in our MS patients. Multiple linear regression analysis showed no significant association between GCs and BMD. In contrast, age, BMI and disease severity were independently associated with both lumbar and femoral BMD. CONCLUSION: Reduced BMD was prevalent in patients with MS. GC treatment appears not to be the primary underlying cause of secondary osteoporosis in MS patients.

Prediction of response to interferon therapy in multiple sclerosis.

OBJECTIVE: Single nucleotide polymorphisms (SNPs) in the genes encoding interferon response factor (IRF)-5, IRF-8 and glypican-5 (GPC5) have been associated with disease activity in multiple sclerosis (MS) patients treated with interferon (IFN)-ß. We analysed whether SNPs in the IRF5, IRF8 and GPC5 genes are associated with clinical disease activity in MS patients beginning de novo treatment with IFN-ß. METHODS: The SNPs rs2004640, rs3807306 and rs4728142 in IRF5, rs13333054 and rs17445836 in IRF8 and rs10492503 in GPC5 were genotyped in 575 patients with relapsing-remitting MS followed prospectively after the initiation of their first treatment with IFN-ß. RESULTS: 62% of patients experienced relapses during the first 2 years of treatment, and 32% had disability progression during the first 5 years of treatment. Patients with a pretreatment annualized relapse rate >1 had an increased risk of relapse (hazard ratio 1.53, 95% confidence interval 1.24-1.90) and progression (hazard ratio 1.48, 95% confidence interval 1.10-1.99) on treatment and patients with breakthrough relapses in the form of relapses during the first 2 years of treatment had an increased risk of progression during the first 5 years of treatment (hazard ratio 2.04, 95% confidence interval 1.47-2.85).The gene variants in IRF5, IRF8 and GPC5 were not associated with risk of relapse or disease progression. CONCLUSIONS: Pretreatment relapse rate and clinical disease activity during the first 2 years of treatment may be associated with disease progression in MS patients treated with IFN-ß. Genetic analysis of the studied gene variants do not provide additional information.

Genetic polymorphisms of dsRNA ligating pattern recognition receptors TLR3, MDA5, and RIG-I. Association with systemic lupus erythematosus and clinical phenotypes.

This study aimed to demonstrate possible associations between genetic polymorphisms in Toll-like receptor 3, interferon induced with helicase C domain 1 (IFIH1) and DEAD (Asp-Glu-Ala-Asp) box polypeptide 58 and systemic lupus erythematosus (SLE), including the phenotypes lupus nephritis and malar rash, as well as the presence of autoantibodies against nucleic acid-containing complexes. Genotyping was carried out in two Danish cohorts [Copenhagen (CPH) and Odense (ODE)] totaling 344 patients and was compared with 641 previously genotyped healthy controls. In the ODE cohort, the patients were only genotyped for the rs1990760 polymorphism of IFIH1. Single nucleotide polymorphisms (SNPs) were determined by a multiplex bead-based assay (CPH cohort) or real-time PCR (ODE cohort). Associations were investigated using the Cochran-Armitage trend test. The odds ratio (OR) for minor allele homozygotes versus major allele homozygotes suggested a protective effect of the IFIH1 rs1990760 SNP for SLE in the ODE cohort [OR 0.52, 95 % confidence intervals (95 % CI) 0.31-0.88, Pcorr. = 0.05] but not in the CPH cohort, although the OR suggested a trend in the same direction, and when combining the two patient cohorts, ORs were 0.57, 95 % CI 0.37-0.88. None of the other investigated polymorphisms showed any association with SLE. Regarding phenotypes, we found a statistically significant association between rs1990760 and malar rash in the CPH cohort, with ORs suggesting a protective effect (OR 0.28, 95 % CI 0.13-0.62 for heterozygotes and OR 0.11, 95 % CI 0.03-0.41 for homozygotes, Pcorr. = 0.0001). There were no significant associations between rs1990760 and presence of anti-dsDNA, anti-U1RNP, or anti-Smith antibodies. Our study supports previous findings of an association between the rs1990760 polymorphism of IFIH1 and SLE and indicates that this SNP may also be associated with malar rash in SLE patients although this finding needs confirmation.

The chemokine receptor CCR5 Δ32 allele in natalizumab-treated multiple sclerosis.

OBJECTIVE: The chemokine receptor CCR5 may be important for the recruitment of pathogenic T cells to the CNS in multiple sclerosis (MS). We hypothesized that this chemokine receptor might still be important for T-cell migration during treatment with anti-very late antigen (VLA)-4 antibody. We therefore analysed whether natalizumab-treated MS patients carrying the CCR5 Δ32 deletion allele, which results in reduced expression of CCR5 on the cell surface, had lower disease activity. METHODS: CCR5 Δ32 was analysed in 212 natalizumab-treated MS patients. RESULTS: CCR5 Δ32 status had no significant impact on the frequency of relapses 1 year prior to natalizumab treatment or during the first 48 weeks of treatment. The multiple sclerosis severity score (MSSS) was significantly lower at baseline in patients carrying CCR5 Δ32 (P = 0.031). CONCLUSIONS: CCR5 Δ32 is not associated with lower disease activity in MS patients treated with natalizumab. We found lower MSSS scores in patients carrying CCR5 Δ32 compared with the remaining patients, which is consistent with previous studies reporting an association with a more favourable disease course. Further studies are, however, needed before the relationship between CCR5 Δ32 and disease activity in MS can be definitely established.

RGMA and IL21R show association with experimental inflammation and multiple sclerosis.

Rat chromosome 1 harbors overlapping quantitative trait loci (QTL) for cytokine production and experimental models of inflammatory diseases. We fine-dissected this region that regulated cytokine production, myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), anti-MOG antibodies and pristane-induced arthritis (PIA) in advanced intercross lines (AILs). Analysis in the tenth and twelfth generation of AILs resolved the region in two narrow QTL, Eae30 and Eae31. Eae30 showed linkage to MOG-EAE, anti-MOG antibodies and levels of interleukin-6 (IL-6). Eae31 showed linkage to EAE, PIA, anti-MOG antibodies and levels of tumor necrosis factor (TNF) and IL-6. Confidence intervals defined a limited set of potential candidate genes, with the most interesting being RGMA, IL21R and IL4R. We tested the association with multiple sclerosis (MS) in a Nordic case-control material. A single nucleotide polymorphism in RGMA associated with MS in males (odds ratio (OR)=1.33). Polymorphisms of RGMA also correlated with changes in the expression of interferon-gamma (IFN-gamma) and TNF in cerebrospinal fluid of MS patients. In IL21R, there was one positively associated (OR=1.14) and two protective (OR=0.87 and 0.68) haplotypes. One of the protective haplotypes correlated to lower IFN-gamma expression in peripheral blood mononuclear cells of MS patients. We conclude that RGMA and IL21R and their pathways are crucial in MS pathogenesis and warrant further studies as potential biomarkers and therapeutic targets.

Genetic variants of CC chemokine genes in experimental autoimmune encephalomyelitis, multiple sclerosis and rheumatoid arthritis.

Multiple sclerosis (MS) is a complex disorder of the central nervous system, causing inflammation, demyelination and axonal damage. A limited number of genetic risk factors for MS have been identified, but the etiology of the disease remains largely unknown. For the identification of genes regulating neuroinflammation we used a rat model of MS, myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE), and carried out a linkage analysis in an advanced intercross line (AIL). We thereby redefine the Eae18b locus to a 0.88 Mb region, including a cluster of chemokine genes. Further, we show differential expression of Ccl2, Ccl11 and Ccl11 during EAE in rat strains with opposite susceptibility to EAE, regulated by genotype in Eae18b. The human homologous genes were tested for association to MS in 3841 cases and 4046 controls from four Nordic countries. A haplotype in CCL2 and rs3136682 in CCL1 show a protective association to MS, whereas a haplotype in CCL13 is disease predisposing. In the HLA-DRB1* 15 positive subgroup, we also identified an association to a risk haplotype in CCL2, suggesting an influence from the human leukocyte antigen (HLA) locus. We further identified association to rheumatoid arthritis in CCL2, CCL8 and CCL13, indicating common regulatory mechanisms for complex diseases.

Efficacy of natalizumab in multiple sclerosis patients with high disease activity: a Danish nationwide study.

INTRODUCTION: Previous studies of natalizumab (Tysabri) in relapsing multiple sclerosis (MS) patients have included patients with moderate disease activity. We studied a patient population with high disease activity. PATIENTS AND METHODS: We analyzed data from 234 consecutive, natalizumab-treated patients, followed for at least 3 months. Three groups of patients were eligible for natalizumab therapy: patients with two or more documented relapses or sustained increase of 2 EDSS points on disease modifying therapy (DMT) in the previous year; patients switching from mitoxantrone; and patients with very active MS as de novo therapy. RESULTS: During a median observation time of 11.3 months (range 3.0-21.5) the annualized relapse rate decreased to 0.68 from a pre-treatment rate of 2.53 (73% reduction). We assessed the annualized relapse rate in three subgroups: (i) 0.83 in 14 (6.0%) de novo treated patients; (ii) 0.71 in 175 (74.8%) patients with >or=2 relapses or sustained increase in EDSS of >or=2 points on a first-line DMT; and (iii) 0.56 in 45 (19.2%) patients switching from mitoxantrone. Nine anaphylactoid reactions, two severe, were reported. Out of 215 patients 7 (3%) were persistently positive for antibodies to natalizumab. CONCLUSIONS: Tysabri appears to be effective in MS patients with high disease activity, but the relapse rate was higher than in the pivotal study after the first treatment year. This is likely to reflect differences in disease activity before the initiation of natalizumab treatment.

Effects of infectious mononucleosis and HLA-DRB1*15 in multiple sclerosis.

BACKGROUND: Both human leukocyte antigen (HLA)-DRB1*15 and Epstein-Barr virus infection presenting as infectious mononucleosis (IM) are recognized as risk factors for multiple sclerosis (MS). However, their combined effect and possible interaction on MS risk is not known. OBJECTIVE: To assess the association between HLA-DRB1*15 and risk of MS in persons with and without IM. METHODS: We compared the prevalence of DRB1*15 in MS patients with (n = 76) and without (n = 1,836) IM with the corresponding distributions in blood donors with (n = 62) and without (n = 484) IM histories. This allowed us to estimate the relative risk of MS associated with DRB1*15 in the presence and absence, respectively, of previous IM. We then estimated the interaction between DRB1*15 and IM as the ratio of the two individual odds ratios. RESULTS: In IM-naïve individuals, DRB1*15 carried a 2.4-fold (95% confidence interval [CI], 2.0-3.0) increased MS risk. In contrast, among persons with IM history, DRB1*15 was associated with a 7.0-fold (95% CI, 3.3-15.4) increased MS risk. Thus, the MS risk conferred by HLA-DRB1*15 was 2.9 (95% CI, 1.3-6.5)-fold stronger in the presence than in the absence of IM. Combined with previous results, this result indicates that DRB1*15-positive persons with a history of IM may be at a 10.0-fold (95% CI, 6.0-17.9) increased risk of MS compared with persons who are DRB1*15 and IM-naïve. CONCLUSION: DRB1*15 and IM may act in synergy causing MS.

Gene expression analysis of interferon-beta treatment in multiple sclerosis.

Treatment with interferon-beta (IFN-beta) induces the expression of hundreds of genes in blood mononuclear cells, and the expression of several genes has been proposed as a marker of the effect of treatment with IFN-beta. However, to date no molecules have been identified that are stably induced by treatment with IFN-beta. We use DNA microarrays to study gene expression in 10 multiple sclerosis (MS) patients who began de novo treatment with IFN-beta. After the first injection of IFN-beta, the expression of 74 out of 3428 genes changed at least two-fold and statistically significantly (after Bonferroni correction). In contrast, we observed no persisting effects of IFN-beta on gene expression. Among the most strongly induced genes was MXA, which has been used in previous biomarker studies in MS. In addition, the study identified the induction of LGALS9 and TCIR1G, involved in negative regulation of T helper type I immunity and T-cell activation, as novel effects of IFN-beta therapy in MS.

X chromosome inactivation in females with multiple sclerosis.

The aetiology of multiple sclerosis (MS) is unknown. Autoimmune mechanisms are most probably involved. Loss of immunological tolerance to self-antigens is a common feature of autoimmune disorders. Response to X-linked self-antigens could be influenced by X-chromosome inactivation, and contribute to the gender bias observed in autoimmune disorders. Previous studies have indicated an association between skewed X inactivation and autoimmune thyroid disease and scleroderma. To investigate a potential role of X inactivation in MS, we compared the X-inactivation pattern in 568 female MS patients with controls. We found no difference in degree of skewing between patients (median 64%) and controls (median 65%) (P = 0.474). The X-inactivation pattern did thus not explain the female predominance of MS patients in general. As the aetiology of different subgroups of MS may differ, patients were grouped according to disease course: relapsing-remitting (RR-MS), secondary progressive (SP-MS) and primary progressive (PP-MS). A comparison of the X-inactivation pattern between subgroups indicated a possible difference in degree of skewing between patients with a progressive versus a relapsing course (P = 0.05).