Danish Multiple Sclerosis Registry Research Articles

Multiple sclerosis in Denmark (1950-2023): mean age, sex distribution, incidence and prevalence.

With rising life expectancy and advancements in disease management, we expect the multiple sclerosis population is getting older. However, evidence supporting this hypothesis remains sparse. Our study aimed to determine whether the mean age of the Danish multiple sclerosis population has increased and to analyse the developments in sex distribution, incidence, and prevalence, all of which affect age composition. We conducted a cohort study by linking nationwide data from the Danish Multiple Sclerosis Registry to the Population Statistics Registry, the Danish Cause of Death Registry, and the Historical Migration Registry. We included all living patients with a confirmed multiple sclerosis diagnosis who lived in Denmark on the 1st of January each year from 1950 to 2023. We calculated the mean and median age, age distribution, sex distribution, incidence, and prevalence of the Danish MS population annually from 1950 to 2023. We included 28,145 individuals with multiple sclerosis. The mean age of the Danish multiple sclerosis population increased until the late 1970s to around 52.5 years, where it stabilised until 1990. The mean age experienced a slight decline to 51.2 years in 2005, followed by a subsequent rise to its peak of 54.2 years in 2023. In 1975, females comprised 58.7% of the multiple sclerosis population, increasing to 65.7% by 2000 and 68.5% in 2023. The incidence of multiple sclerosis remained stable at around 3.5 per 100,000 until 1975 and steadily increased by more than 2.5 times in 2000 to 11.4 per 100,000. Despite fluctuations, it remained relatively stable from 2000 until 2022, showing a slight decrease in 2022 compared to the previous two decades. Both overall and sex-specific prevalence exhibited an upward trend, particularly among females. Our study demonstrates that the mean age of the Danish multiple sclerosis population has increased, although not as decisively as expected. The female proportion has grown in tandem with prevalence, while incidence appears to have stabilised in recent decades after years of increase. Denmark's robust registry data and universal healthcare system offer a unique opportunity for reliable epidemiological analysis. Our results establish a benchmark for future demographic studies in the field of multiple sclerosis.

Long-Term Safety of Teriflunomide in Multiple Sclerosis Patients: Results of Prospective Comparative Studies in Three European Countries.

Teriflunomide is a disease-modifying therapy (DMT) for multiple sclerosis (MS). This post authorisation safety study assessed risks of adverse events of special interest (AESI) associated with teriflunomide use. Secondary use of individual data from the Danish MS Registry (DMSR), the French National Health Data System (SNDS), the Belgian national database of health care claims (AIM-IMA) and the Belgian Treatments in MS Registry (Beltrims). We included patients treated with a DMT at the date of teriflunomide reimbursement or initiating another DMT. Adjusted hazard rates (aHR) and 95% confidence intervals were derived from Cox models with time-dependent exposure comparing teriflunomide treatment with another DMT. Of 81 620 patients (72% women) included in the cohort, 22 324 (27%) were treated with teriflunomide. After a median follow-up of 4 years, teriflunomide use compared to other DMT was not associated with a risk of all-cause mortality, severe infection, pneumoniae, herpes zoster reactivation, pancreatitis, cardiovascular condition and cancers. For opportunistic infections, aHR for teriflunomide versus other DMT was 2.4 (1.2-4.8) in SNDS, which was not bound to a particular opportunistic agent. The aHR was 2.0 (1.1-3.7) for renal failures in the SNDS, but no association was found in other data sources. A total of 187 SNDS patients had a history of renal failure prior to cohort entry. None of these patients (0%) had a renal failure recurrence when treated with teriflunomide for 19 (13%) recurrences reported for patients on another DMT. We found no evidence that teriflunomide use would be associated with an increased risk of AESI. Trial Registration EUPAS register: EU PAS 19610.

Reevaluating the role of interferon-beta in psoriasis pathogenesis: A registry-based self-controlled study.

Interferon-beta has been suggested as a trigger of psoriasis, yet a systematic investigation is lacking. This study aimed to assess the risk of developing psoriasis following interferon-beta treatment, utilizing a pharmaco-epidemiological approach to investigate the role of interferon-beta in psoriasis pathogenesis. We included all treatment-naïve patients with multiple sclerosis (MS) in Denmark who initiated interferon-beta treatment for MS from January 1996 to June 2023. These patients were compared to a control cohort of patients with MS treated with other disease-modifying drugs. We compared the incidence rates of psoriasis before and during the treatment. Data for this study were extracted from the Danish MS Registry and integrated with information from other national Danish health registries. Among 7174 patients treated with interferon-beta, the incidence rate of psoriasis post-treatment initiation was slightly higher (2.01 per 1000 person-years) compared to the rate prior to treatment (1.67 per 1000 person-years). This increase did not achieve statistical significance (P = 0.53), with an incidence rate ratio (IRR) of 1.20 (95% confidence interval [CI] 0.68-2.13). The control cohort showed an increase in psoriasis incidence post-treatment initiation (3.12 per 1000 person-years) compared to prior (1.11 per 1000 person-years), with an IRR of 2.80 (95% CI 1.36-4.77, P = 0.0038). This registry-based self-controlled study does not support the theory that interferon-beta acts as a trigger for psoriasis development.

Sleep Disorders and Sleep Disturbances in Persons with Multiple Sclerosis: A Population-Based Matched Case-Control Study in Denmark

Introduction: Adverse sleep is common in multiple sclerosis (MS). Population-based studies including adequate control groups are lacking. We hypothesized that the prevalence of sleep disorders and other sleep disturbances would be higher in persons with MS than in controls. Methods: We conducted a population-based study linking individual-level data from the Danish MS Registry (n = 21,943 persons with MS) and the Danish Population Registry (n = 109,715 matched controls) with information on sleep disorders from the Danish National Patient Registry and other sleep disturbances assessed by dispensed prescription drugs from the Danish National Prescription Registry. Results: Prevalence of diagnosed sleep disorders in terms of central hypersomnia (0.15% vs. 0.06%), sleep disturbances (1.05% vs. 0.70%), and sleep movements (0.22% vs. 0.13%) and other sleep disturbances identified by dispensed central acting (10.73% vs. 1.10%) and hypnotic use (30.65% vs. 20.13%) medication was statistically significantly higher among persons with MS when compared to controls. We found no statistically significant difference in the prevalence of sleep apnea and parasomnia between groups. Stratified by sex and age at MS diagnosis, results for differences between persons with MS and controls were similar. Conclusion: In this registry-based study, we found that the prevalence of several diagnosed sleep disorders was higher in persons with MS than in controls, that is, those reflecting insomnia and daytime symptoms including hypersomnia. Other sleep disturbances identified by dispensed prescription medication were markedly higher in persons with MS than in controls.

Mortality of the Danish Nationwide AQP4 Antibody-Seropositive Neuromyelitis Optica Spectrum Disorder Patient Cohort.

We aimed to evaluate the mortality of patients with AQP4 antibody-seropositive (AQP4-Ab+) neuromyelitis optica spectrum disorder (NMOSD) in Denmark compared with that in the general population. We identified patients with AQP4-Ab+ NMOSD fulfilling the 2015 International Panel for Neuromyelitis Optica Diagnosis (IPND) criteria from multiple sources (laboratories and the Danish Multiple Sclerosis Registry). We obtained detailed information about patients from hospital records and about the general population matched on age, sex, and calendar year from Statistics Denmark. We calculated standardized mortality ratio (SMR), excess number of deaths per 1,000 person-years (EDR), and life expectancies compared with those of the matched general population. We examined predictive factors of mortality and the cause of death. Of 66 patients with AQP4-Ab+ NMOSD between 2008 and 2020, 15 died. Overall, the SMR was 2.54 (95% CI 1.47-4.09), and the EDR was 16.8 (95% CI 4.6-34.3). The median life expectancy for patients with AQP4-Ab+ NMOSD was 64.08 years (95% CI 53.02-83.9), compared with 83.07 years for the general population. Risk of death over time was increased in the patient population with a hazard ratio (HR) of 2.22 (1.34-3.68; p = 0.002). The cause of death was directly related to NMOSD in 93% of the cases. The age at disease onset was an independent predictor of death (HR 1.042; 95% CI 1.006-1.079; p = 0.02). AQP4-Ab+ NMOSD is associated with increased mortality and shorter life expectancy compared with that in the general population, underlining the need for highly effective treatment approaches.

Risk of cardiovascular disease in patients with multiple sclerosis treated with fingolimod compared to natalizumab: A nationwide cohort study of 2095 patients in Denmark.

Fingolimod may be associated with risk of developing cardiovascular disease (CVD). Studies including reference groups and long follow-up are scarce. We hypothesized that patients treated with fingolimod would be at higher risk of developing CVD compared to patients treated with natalizumab. A nationwide 12-year cohort study linking individual-level data from the Danish Multiple Sclerosis Registry with health registries on 2095 adult patients with multiple sclerosis (MS) without any health records of CVD at follow-up start. Exposure to fingolimod and natalizumab was defined by the first treatment of at least 3 months. Cohort entry was from 2011 to 2018. We defined CVD as a composite measure, including hypertension, ischemic heart disease, atrial fibrillation, heart failure, and stroke. We used multivariable adjusted Cox regression. There were 28.8 and 17.4 CVD events per 1000 person-years in fingolimod and natalizumab groups, respectively. Compared to natalizumab-treated patients, fingolimod-treated patients had a higher risk of CVD (hazard ratio (HR) = 1.57; 95% confidence interval (CI) = 1.18-2.08). Hypertension comprised 200 of 244 CVD events. We found an increased risk of CVD in patients with MS treated with fingolimod. This increased risk was mainly due to hypertension.

Comorbidity in the aging population with multiple sclerosis: a Danish nationwide study

IntroductionMultiple sclerosis (MS) is a neurodegenerative disease accumulating disabilities over time. However, the mean age of individuals with MS is increasing, consequently elevating their risk of developing comorbidities. Comorbidities' impact on MS is widely debated. Yet very few countries possess population-based registries, which provide unique opportunities for individual-level data linkage. This study aims to assess acute and chronic comorbidities among elderly patients with MS, comparing them to matched controls. Additionally, this study seeks to investigate the influence of chronic comorbidities on all-cause mortality.MethodsA nationwide register-based study using the Danish Multiple Sclerosis Registry to identify all living patients with MS older than 50 years at the reference date (January 1st, 2022). Patients were matched 1:10 with individuals from the general population. Comprehensive healthcare data within the Danish hospital system were obtained. Chronic comorbidities were classified according to the Charlson Comorbidity Index, while acute comorbidities were based on ICD-10 codes and an “acute” admission type. To investigate all-cause mortality, a Cox regression analysis was conducted.ResultsThe study encompassed a total of 8,688 individuals with MS, matched with 86,880 controls. The mean age was 63.5 years, with females constituting 68.3%. Individuals with MS exhibited a higher frequency of acute hospitalizations (OR: 2.1, 95% CI: 1.9–2.2), primarily due to various infectious diseases, along with longer median hospital stays (4 vs. 3 days, p < 0.001). When assessed using the Charlson Comorbidity Index, individuals with MS carried a significantly greater burden of chronic comorbidities (p < 0.001). The most prevalent chronic comorbidity among individuals with MS was “Uncomplicated Diabetes” (20.1%). Notably, while individuals with MS displayed an overall lower 5-year survival rate, this difference ceased to be statistically significant among those with a high Charlson Comorbidity Index score of ≥4 (p = 0.32).ConclusionThis study highlights a heightened prevalence of both acute and chronic comorbidities among individuals with MS, with chronic comorbidities significantly increasing the risk of mortality. These findings underscore the critical importance of factoring in comorbidities when devising treatment strategies for individuals living with MS.

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.

Interferon-beta exposure in-utero and the risk of infections in early childhood.

Knowledge within the field of multiple sclerosis treatment during pregnancy is vital to ensure the most optimal clinical practice. Immunomodulatory treatment in pregnancy could in theory affect the normal development and maturation of the immune system of the fetus with a potential increased risk of infections, consequently. We therefore set out to investigate whether exposure to interferon-beta in utero affected the risk of acquiring infections in early childhood. This retrospective matched cohort study utilized data from the Danish Multiple Sclerosis Registry linked with national Danish registries to identify all children born of mothers with MS in Denmark from 1998 to 2018. The study included 510 children exposed to interferon-beta in utero. The children were matched 1:1 on various of demographic characteristics with children born to mothers with untreated MS and 1:3 with children born to mothers without MS. Each child was followed for up to five years. Using individual-level data, we investigated all-cause mortality, rate of hospital admissions due to infections, and redeemed prescriptions of antibiotics. The primary statistical model applied was a negative binomial regression analysis. We found no differences in childhood mortality, for hospital admissions the rate ratio compared to healthy controls was 0.79 (0.62-1.00). Regarding antibiotic prescriptions, the results were similar (RR 1.00 (0.90-1.11). Furthermore, we found no certain dose-response relationship between interferon-beta exposure duration and hospital admission rate (P=0.47) or redeemed antibiotic prescription (P=0.71). Exposure to interferon-beta during gestation has little to no impact on the risk of acquiring significant infections during the first five years of childhood.

Socioeconomic status of the elderly MS population compared to the general population: a nationwide Danish matched cross-sectional study.

Multiple sclerosis (MS) leads to physical and cognitive disability, which in turn impacts the socioeconomic status of the individual. The altered socioeconomic trajectory combined with the critical role of aging in MS progression could potentially lead to pronounced differences between MS patients and the general population. Few nations have the ability to connect long-term clinical and socioeconomic data at the individual level, and Denmark's robust population-based registries offer unique insights. This study aimed to examine the socioeconomic aspects of elderly Danish MS patients in comparison to matched controls from the general population. A nationwide population-based study in Denmark was conducted, comprising all living MS patients aged 50 years or older as of 1 January 2021. Patients were matched 1:10 based on sex, age, ethnicity, and residence with a 25% sample of the total Danish population. Demographic and clinical information was sourced from the Danish Multiple Sclerosis Registry, while socioeconomic data were derived from national population-based registries containing details on education, employment, social services, and household characteristics. Univariate comparisons between MS patients and matched controls were then carried out. The study included 8,215 MS patients and 82,150 matched individuals, with a mean age of 63.4 years (SD: 8.9) and a 2:1 female-to-male ratio. For those aged 50-64 years, MS patients demonstrated lower educational attainment (high education: 28.3 vs. 34.4%, P < 0.001) and fewer received income from employment (46.0 vs. 78.9%, P < 0.001), and working individuals had a lower annual income (48,500 vs. 53,500€, P < 0.001) in comparison to the controls. Additionally, MS patients within this age group were more likely to receive publicly funded practical assistance (14.3 vs. 1.6%, P < 0.001) and personal care (10.5 vs. 0.8%, P < 0.001). Across the entire population, MS patients were more likely to live alone (38.7 vs. 33.8%, P < 0.001) and less likely to have one or more children (84.2 vs. 87.0%, P < 0.001). MS presents significant socioeconomic challenges among the elderly population, such as unemployment, reduced income, and increased dependence on social care. These findings underscore the pervasive impact of MS on an individual's life course, extending beyond the clinical symptoms of cognitive and physical impairment.

Rituximab vs Ocrelizumab in Relapsing-Remitting Multiple Sclerosis

Ocrelizumab, a humanized monoclonal antibody targeted against CD20+ B cells, reduces the frequency of relapses by 46% and disability worsening by 40% compared with interferon beta 1a in relapsing-remitting multiple sclerosis (MS). Rituximab, a chimeric monoclonal anti-CD20 agent, is often prescribed as an off-label alternative to ocrelizumab. To evaluate whether the effectiveness of rituximab is noninferior to ocrelizumab in relapsing-remitting MS. This was an observational cohort study conducted between January 2015 and March 2021. Patients were included in the treatment group for the duration of study therapy and were recruited from the MSBase registry and Danish MS Registry (DMSR). Included patients had a history of relapsing-remitting MS treated with ocrelizumab or rituximab, a minimum 6 months of follow-up, and sufficient data to calculate the propensity score. Patients with comparable baseline characteristics were 1:6 matched with propensity score on age, sex, MS duration, disability (Expanded Disability Status Scale), prior relapse rate, prior therapy, disease activity (relapses, disability accumulation, or both), magnetic resonance imaging lesion burden (missing values imputed), and country. Treatment with ocrelizumab or rituximab after 2015. Noninferiority comparison of annualized rate of relapses (ARRs), with a prespecified noninferiority margin of 1.63 rate ratio. Secondary end points were relapse and 6-month confirmed disability accumulation in pairwise-censored groups. Of the 6027 patients with MS who were treated with ocrelizumab or rituximab, a total of 1613 (mean [SD] age; 42.0 [10.8] years; 1089 female [68%]) fulfilled the inclusion criteria and were included in the analysis (898 MSBase, 715 DMSR). A total of 710 patients treated with ocrelizumab (414 MSBase, 296 DMSR) were matched with 186 patients treated with rituximab (110 MSBase, 76 DMSR). Over a pairwise censored mean (SD) follow-up of 1.4 (0.7) years, the ARR ratio was higher in patients treated with rituximab than in those treated with ocrelizumab (rate ratio, 1.8; 95% CI, 1.4-2.4; ARR, 0.20 vs 0.09; P < .001). The cumulative hazard of relapses was higher among patients treated with rituximab than those treated with ocrelizumab (hazard ratio, 2.1; 95% CI, 1.5-3.0). No difference in the risk of disability accumulation was observed between groups. Results were confirmed in sensitivity analyses. In this noninferiority comparative effectiveness observational cohort study, results did not show noninferiority of treatment with rituximab compared with ocrelizumab. As administered in everyday practice, rituximab was associated with a higher risk of relapses than ocrelizumab. The efficacy of rituximab and ocrelizumab administered at uniform doses and intervals is being further evaluated in randomized noninferiority clinical trials.

Natalizumab treatment of multiple sclerosis - a Danish nationwide study with 13 years of follow-up.

Natalizumab is a widely used high-efficacy treatment in multiple sclerosis (MS). Real-world evidence regarding long-term effectiveness and safety is warranted. We performed a nationwide study evaluating prescription patterns, effectiveness, and adverse events. A nationwide cohort study using the Danish MS Registry. Patients initiating natalizumab between June 2006 and April 2020 were included. Patient characteristics, annualized relapse rates (ARRs), confirmed Expanded Disability Status Scale (EDSS) score worsening, MRI activity (new/enlarging T2- or gadolinium-enhancing lesions), and reported adverse events were evaluated. Further, prescription patterns and outcomes across different time periods ("epochs") were analysed. In total, 2424 patients were enrolled, with a median follow-up time of 2.7 years (interquartile range (IQR) 1.2-5.1). In recent epochs, patients were younger, had lower EDSS scores, had fewer pre-treatment relapses and were more often treatment naïve. At 13 years of follow-up, 36% had a confirmed EDSS worsening. On-treatment ARR was 0.30, corresponding to a 72% reduction from pre-initiation. MRI activity was rare, 6.8% had activity within 2-14 months from treatment start, 3.4% within 14-26 months, and 2.7% within 26-38 months. Approximately 14% of patients reported adverse events, with cephalalgia constituting the majority. During the study, 62.3% discontinued treatment. Of these, the main cause (41%) was due to JCV antibodies, while discontinuations due to disease activity (9%) or adverse events (9%) were less frequent. Natalizumab is increasingly used earlier in the disease course. Most patients treated with natalizumab are clinically stable with few adverse events. JCV antibodies constitute the main cause for discontinuation.

The uncertainty period preceding the clinical defined SPMS diagnosis and the applicability of objective classifiers - A Danish single center study.

The clinical transition from relapsing-remitting multiple sclerosis (RRMS) to secondary progressive MS (SPMS) is often related to a period of diagnostic uncertainty delaying diagnosis. With emerging treatment options for SPMS how to identify RRMS patients at risk of SPMS and when to assign a SPMS diagnosis has become a matter of growing clinical concern. This study aimed to determine the period of diagnostic uncertainty among Danish MS patients. Secondly, this study examined the performance of two objective classifiers in a longitudinal setting regarding their ability to shorten the period of diagnostic uncertainty. By using the Danish Multiple Sclerosis Registry, we identified all patients linked to Rigshospitalet with clinically assigned SPMS from 2010 to 2021. We reviewed all patient records and identified the first mentioned sign of progression (FMP). The time between the dates of FMP and clinically assigned SPMS was defined as the period of diagnostic uncertainty. Secondly, we applied two objective classifiers (the Karolinska Decision tree and the MSBase criteria) to generate suggested transition dates and compared them to the ones obtain from the patient records. Detailed descriptions of the population were made at all mentioned timepoints. In total 138 patients were included. We found a median period of diagnostic uncertainty of 2.12 years. The objective classifiers generated a median suggested transition date 3.44 and 4.48 years earlier than the date of clinically assigned SPMS, but they only provided an earlier SPMS transition date in 50.72% and 55.80% of cases. Our findings emphasize the uncertainty related to the transition from RRMS to SPMS illustrating the need of an improved diagnostic approach. Objective classifiers might have the potential to help reduce the period of diagnostic uncertainty in the future, but in their current form they do not perform satisfactorily enough to solve all difficulties related to detecting SPMS-transition.

Assisted reproductive technology treatment and risk of multiple sclerosis – a Danish cohort study

To compare the incidence of multiple sclerosis (MS) among women who had undergone assisted reproductive technology (ART) treatment with the women who had conceived a child without previous ART treatment. A register-based nationwide cohort study. Women with a first ovarian stimulation cycle before invitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) (i.e., ART treatment) recorded in the Danish IVF register between 1996 and 2018; and women recorded in the Danish Medical Birth Register with the birth of their first child where date of conception is between 1996 and 2018. The cohort was observed until March 10,2021. Mainly included IVF, ICSI, and fresh embryo transfer with hormone stimulation. A diagnosis of MS recorded in the Danish Multiple Sclerosis Registry. Crude and adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) were calculated. A total of 585,716 women were included in the cohort of which 63,791 (11%) were exposed to at least one initiated IVF or ICSI cycle during the study period. Cycles with oocyte donation were excluded. The median follow-up time for the entire cohort was 12.4 years (Q1-Q3= 6.6-18.1). Compared with women conceiving without previous ART, ART treated women were older (31.8 years vs. 27.5 years), more often had a university degree (45% vs. 36%), and more often had received other fertility treatments than IVF or ICSI before cohort entry (26% vs. 3%). We found no association between incident MS and exposure to ART compared with non-ART pregnancy (aHR=1.08; 95 % CI, 0.93-1.25). An analysis following intention-to-treat principle on a propensity score matched sub cohort confirmed our results. In subgroup analysis including all ART cycles among the ART treated women, we found no increased risk of MS within 2 years of ART cycle start for successful ART cycles (pregnancy) compared with failed ART cycles (no pregnancy) (aHR=1.01; 95% CI, 0.58-1.76). We found a non-significant trend toward increased risk of MS with increasing numbers of ART cycles although based on small numbers. Women treated with ART do not seem to be at increased risk of developing MS compared with the women not exposed to ART.

Intravenous ofatumumab treatment of multiple sclerosis and related disorders: An observational study

BackgroundOfatumumab is an anti-CD20 monoclonal antibody approved for subcutaneous administration for the treatment of relapsing multiple sclerosis (MS), but intravenously administered ofatumumab has been investigated in a phase 2 trial and used off-label. The objective of the present study was to assess disease activity and side effects in relation to longer-term intravenous ofatumumab treatment of MS and related disorders. MethodsWe conducted a retrospective study of patients treated off-label with intravenous ofatumumab for MS, neuromyelitis optica spectrum disease (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) at the Danish Multiple Sclerosis Center. Data was retrieved from the Danish Multiple Sclerosis Registry and through medical chart review. ResultsFifty patients were identified with a median treatment duration of 2.2 years. Annualized relapse rate decreased from 1.03 at baseline to 0.38 during ofatumumab treatment. At 24 months, the probability of having experienced a relapse was 55% and confirmed disability worsening 7%. Frequency of infusion-related reactions was 86% during the first infusion and 42% during the last infusion. Six experienced infections requiring hospitalization. ConclusionOur data indicate a reduction of relapse frequency, stabilization of disability worsening and an acceptable safety profile, although we observed a higher frequency of infusion reactions compared to data from other intravenously administered anti-CD20 monoclonal antibodies. The study supports a class effect of anti-CD20 monoclonal antibodies and the hypothesis that complement activation may be associated to a higher frequency of infusion related reactions.

Pregnancy outcomes after early fetal exposure to injectable first-line treatments, dimethyl fumarate, or natalizumab in Danish women with multiple sclerosis.

Data on pregnancy outcomes following fetal exposure to disease-modifying drugs (DMDs) in women with multiple sclerosis (MS) are sparse although growing. Data from the Danish Multiple Sclerosis Registry were linked with nationwide registries enabling an investigation of adverse pregnancy outcomes in newborns of women with MS following fetal exposure to injectable first-line treatments, dimethyl fumarate, glatiramer acetate, or natalizumab. Logistic regression models accounting for clustered data were used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for individual and composite adverse outcomes after adjusting for relevant covariates. A total of 1009 DMD-exposed pregnancies were compared with 1073 DMD-unexposed pregnancies as well as 91,112 pregnancies from the general population. No association of an increased risk of any perinatal outcome was found when comparing newborns with fetal exposure with the general population, including preterm birth (OR=1.19, 95% CI=0.86-1.64), small for gestational age (OR=1.38, 95% CI=0.92-2.07), spontaneous abortion (OR=1.04, 95% CI=0.84-1.27), congenital malformation (OR=0.99, 95% CI=0.68-1.45), low Apgar score (OR=0.62, 95% CI=0.23-1.65), stillbirth (OR=1.05, 95% CI=0.33-3.31), placenta complication (OR=0.53, 95% CI=0.22-1.27), and any adverse event (OR=1.10, 95% CI=0.93-1.30). Similar results were found when comparing DMD-exposed pregnancies with DMD-unexposed pregnancies. We found no increased association of adverse pregnancy outcomes in newborns with fetal exposure to DMDs when compared with either DMD-unexposed pregnancies or the general population.

Risk factors for development of lymphopenia in dimethyl fumarate-treated patients with multiple sclerosis

BackgroundDimethyl fumarate (DMF, Tecfidera®) is a first-line disease-modifying therapy for relapsing-remitting multiple sclerosis. Lymphopenia is a frequent reason for discontinuation in fumarate-treated patients. Management strategies to minimize risk of lymphopenia are warranted. ObjectiveThe aims of this study were to investigate the correlation of body mass index (BMI), baseline absolute lymphocyte count (ALC), age and sex with risk of DMF-induced lymphopenia in MS patients. MethodsThe study was a retrospective cohort study of 452 MS patients who had been prescribed DMF at six clinics in two Danish regions between May 2014 and September 2017. Data on lymphocyte counts, BMI, age, sex, and reason for discontinuation of DMF were collected through the Danish Multiple Sclerosis Registry, with follow- up to two years after treatment start. Results28.5% of patients had lymphopenia grade II or higher at some time in the first two years of DMF treatment. Increased risk of lymphopenia was observed in patients with baseline ALC of 1.00–1.49×109 cells/L (odds ratio, OR 5.48, p<0.0001) and 1.50–1.99×109 cells/L (OR 2.08, p = 0.0009). Reduced risk of lymphopenia was observed in patients with ALC of 2.00–2.49×109 cells/L (OR 0.51, p< 0.01) and ≥ 2.50×109 cells/L (0.12, p<0.0001). Patients aged ≥ 56 years had an increased risk of lymphopenia (OR 3.58, p<0.001), and patients with BMI ≥ 30 kg/m2 had a decreased risk of lymphopenia (OR 0.53, p value = 0.03). ConclusionLow baseline ALC and older age were risk factors for DMF-induced lymphopenia, while BMI ≥ 30 kg/m2 and high baseline ALC were protective factors for developing lymphopenia in MS patients treated with DMF.

Changes in prognosis of the Danish multiple sclerosis population over time

Background: The course of multiple sclerosis (MS) appears to be milder in recent decades. Objective: To investigate how time from onset to disability milestones and how demographic and clinical characteristics have changed through subsequent onset cohorts of patients with MS. Methods: In the nationwide Danish Multiple Sclerosis Registry, we have registered all 13,562 Danish patients with onset of MS or clinically isolated syndrome from 1996 through 2020. For the analyses of prognosis, we used all cases with relapsing onset (N = 11,669). After stratification into 5-year onset cohorts, we computed the hazard ratios for disability endpoints for all cohorts having at least 10 years of follow-up and the oldest 1996–2000 onset cohort as reference. Results: Patients in more recent MS onset cohorts have a shorter diagnostic delay and more of them start disease-modifying treatment within 1 year since diagnosis. The prognosis was better for later onset cohorts. For the 2001–2005 cohort, the hazard ratio for confirmed Expanded Disability Status Scale (EDSS) 4 was 0.85 (95% confidence interval (CI), 0.76–0.95) and for confirmed EDSS 6: 0.76 (95% CI, 0.65–0.88). For the more recent 2006–2010 cohort, the corresponding hazard ratios were 0.70 (95% CI, 0.62–0.79) and 0.60 (95% CI, 0.50–0.71). Conclusion: We observed a considerable improvement of the prognosis in recent onset cohorts of relapsing-onset MS.

Time to first treatment and risk of disability pension in relapsing-remitting multiple sclerosis

Background Initiation of disease-modifying therapy early in the disease course of relapsing-remitting multiple sclerosis (RRMS) has demonstrated beneficial effects on clinical outcomes, but socioeconomic outcomes remain largely unexplored.Objective To investigate...

Quantitative effect of sex on disease activity and disability accumulation in multiple sclerosis

ObjectiveTo quantify sex differences in activity and severity of multiple sclerosis (MS) and how it depends on disease duration and time since clinical onset.MethodsAll Danish citizens with onset of relapsing...