The CLARION study: first report on safety findings in patients newly initiating treatment with cladribine tablets or fingolimod for multiple sclerosis

OBJECTIVES

As part of the CLARION study: (1) characterize the incidence of severe infections, herpes zoster, and malignancies in patients newly initiating cladribine or fingolimod for relapsing multiple sclerosis (MS); (2) estimate the incidence of severe lymphopenia among cladribine users; and (3) describe prior/subsequent disease-modifying therapy (DMT) in both cohorts.

METHODS

Patients were identified from seven participating MS registries/data sources. The incidence rate (IR) of each outcome per 1000 patient-years and its 95% confidence interval (95%CI) were estimated for cohorts using Poisson regression.

RESULTS

By cut-off date (01-April-2020), 742 cladribine and 867 fingolimod users were included. Mean follow-up was ∼1 year. The IR for severe infections from all contributing sources (except Denmark) was: cladribine, 7.37 (2.76,19.6); fingolimod, 6.55 (2.46,17.4). The corresponding IR for herpes zoster was 5.51 (1.78,17.1) and 3.27 (0.82,13.1), respectively, while values for opportunistic infections were 0 (0,6.76) and 1.63 (0.23,11.6), respectively. There were no events of progressive multifocal leukoencephalopathy in either cohort. The IR of severe lymphopenia was 63.9 (40.7,100.1) in 349 cladribine users from contributing sources. The IR of malignancies (cut-off date 01-April-2022) was 3.55 (1.59,7.90) for the cladribine cohort (n = 1035) and 3.55 (1.48,8.52) for the fingolimod cohort (n = 843) from three MS registries/data sources. In the combined data sources, 36.8% of cladribine and 27.4% of fingolimod users were DMT-naïve; after initiation of study treatment, 2.5% and 20.2% switched to another DMT, respectively.

CONCLUSION

No new safety signal was observed in patients treated with cladribine tablets, although results are limited by a relatively short duration of follow-up.

Real-world treatment outcomes and safety of natalizumab in Finnish multiple sclerosis patients

Objectives

The primary objective was to evaluate long-term treatment persistence and safety of natalizumab in Finnish multiple sclerosis patients. The secondary objectives were to assess patient characteristics, use of natalizumab-related safety protocol, and treatment persistence in patients with different anti-John Cunningham virus antibody statuses (John Cunningham virus status).

Materials & Methods

All adult multiple sclerosis patients in the Finnish multiple sclerosis register who started natalizumab between 1/2006 and 12/2018 were included in this study and followed retrospectively until treatment discontinuation or end of follow-up (12/2019).

Results

In total, 850 patients were included. Median duration of natalizumab treatment was 7.8 years in John Cunningham virus negative (n = 229) and 2.1 years in John Cunningham virus positive patients (n = 115; p < 0.001). The most common cause for treatment discontinuation was John Cunningham virus positivity. After natalizumab discontinuation, patients who had a washout duration of less than 6 weeks had fewer relapses during the first 6 months (p = 0.012) and 12 months (p = 0.005) compared with patients who had a washout duration of over 6 weeks. During the median follow-up of 3.6 years, 76% of patients remained stable or improved on their Expanded Disability Status Scale.

Conclusions

Treatment persistence was very high among John Cunningham virus negative patients. The study supports long-term effectiveness of natalizumab and a washout duration of less than 6 weeks after discontinuation.

Exposure to systemic antibiotics in outpatient care and the risk of multiple sclerosis

BACKGROUND

Infections, early life exposures and the microbiome have been associated with the aetiology of multiple sclerosis (MS). Data on any possible roles of antibiotics is scarce and conflicting.

OBJECTIVE

The objective of this study was to investigate associations between outpatient systemic antibiotic exposure and the risk of MS in a nationwide case-control setting.

METHODS

Patients with MS were identified from the nation MS registry and their exposure to antibiotics was compared with that of persons without MS, provided by the national census authority. Antibiotic exposure was investigated using the national prescription database and analyzed by Anatomical Therapeutic Chemical (ATC) category.

RESULTS

Among the 1830 patients with MS and 12765 control persons, there were no associations between exposure to antibiotics in childhood (5-9 years) or adolescence (10-19 years) and the subsequent risk of MS. There was also no association between antibiotic exposure 1-6 years before disease onset and the risk of MS, save for exposure to fluoroquinolones in women (odds ratio: 1.28; 95% confidence interval: 1.03, 1.60; p = 0.028) which is probably associated with the increased infection burden in the MS prodrome.

CONCLUSION

Use of systemic prescription antibiotics was not associated with subsequent MS risk.

Proportion and characteristics of secondary progressive multiple sclerosis in five European registries using objective classifiers

Background

To assign a course of secondary progressive multiple sclerosis (MS) (SPMS) may be difficult and the proportion of persons with SPMS varies between reports. An objective method for disease course classification may give a better estimation of the relative proportions of relapsing-remitting MS (RRMS) and SPMS and may identify situations where SPMS is under reported.

Materials and methods

Data were obtained for 61,900 MS patients from MS registries in the Czech Republic, Denmark, Germany, Sweden, and the United Kingdom (UK), including date of birth, sex, SP conversion year, visits with an Expanded Disability Status Scale (EDSS) score, MS onset and diagnosis date, relapses, and disease-modifying treatment (DMT) use. We included RRMS or SPMS patients with at least one visit between January 2017 and December 2019 if ≥ 18 years of age. We applied three objective methods: A set of SPMS clinical trial inclusion criteria ("EXPAND criteria") modified for a real-world evidence setting, a modified version of the MSBase algorithm, and a decision tree-based algorithm recently published.

Results

The clinically assigned proportion of SPMS varied from 8.7% (Czechia) to 34.3% (UK). Objective classifiers estimated the proportion of SPMS from 15.1% (Germany by the EXPAND criteria) to 58.0% (UK by the decision tree method). Due to different requirements of number of EDSS scores, classifiers varied in the proportion they were able to classify; from 18% (UK by the MSBase algorithm) to 100% (the decision tree algorithm for all registries). Objectively classified SPMS patients were older, converted to SPMS later, had higher EDSS at index date and higher EDSS at conversion. More objectively classified SPMS were on DMTs compared to the clinically assigned.

Conclusion

SPMS appears to be systematically underdiagnosed in MS registries. Reclassified patients were more commonly on DMTs.

Initial treatment strategy and clinical outcomes in Finnish MS patients: a propensity-matched study

Background

The optimal treatment strategy with disease-modifying therapies (DMTs) in relapsing–remitting multiple sclerosis (RRMS) remains uncertain.

Objective

To compare outcomes of initial treatment with infusion therapies and starting therapy with medium efficacy therapy in a propensity-matched cohort of Finnish RRMS patients.

Methods

A total of 154 RRMS patients initiating natalizumab, alemtuzumab, ocrelizumab or rituximab as first DMT (high efficacy DMT, heDMT group) and 1771 patients initially treated with injectable therapies, teriflunomide or dimethylfumarate and escalated based on disease activity (moderate efficacy DMT, meDMT group) were identified from the Finnish MS registry. Nearest neighbor propensity matching (1:1, caliper 0.1) was performed for age, sex, baseline Expanded Disability Status Scale (EDSS), annual relapse rate (ARR) one year prior DMT and time since MS symptom onset. Primary outcome was time to 6-month confirmed EDSS progression and the secondary outcome time to first relapse.

Results

In the propensity-matched group comparisons, the probability of 6-month confirmed disability progression (CDP) at 5 years after DMT start was 28.4% (95% CI 15.7–39.3) in the heDMT group (n = 66) and 47.0% (95% CI 33.1–58.1) in meDMT group (n = 66), p = 0.013. Probability of relapse at 5 years was 34.6% (95% CI 24.1–43.6) for heDMT (n = 105) and 47.2% (95% CI 36.6–56.1) for meDMT (n = 105), p = 0.019.

Conclusions

Initiating MS-therapy with heDMT significantly reduced the risk of 5-year disability progression and relapse compared to using meDMT as first DMT choice in propensity-matched groups of Finnish MS-patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10673-9.

Vitamin D supplementation and serum neurofilament light chain in interferon-beta-1b-treated MS patients

OBJECTIVES

Serum neurofilament light chain (sNfL) is a promising biomarker of MS activity, progression, and treatment response. The aim of the present study was to address whether sNfL concentrations are affected by supplementation of vitamin D and correlate with disease activity in interferon-beta-1b (IFNb-1b)-treated Finnish MS.

MATERIALS AND METHODS

Serum samples were available of 32 participants of the Finnish vitamin D randomized controlled trial (17 vitamin D/15 placebo). Serum 25 hydroxyvitamin D was measured using radioimmunoassay and sNfL using single-molecule array (Simoa). Correlation of sNfL with brain magnetic resonance imaging (MRI) activity, burden of disease (BOD, mm³ ), and disability was assessed at the study baseline and at 52 weeks.

RESULTS

Serum NfL concentrations were similar in the patients randomized to high-dose vitamin D and placebo at the study baseline and at month 12 follow-up (p-value). Concentrations of sNfL were higher in patients with Gadolinium-enhancing lesions in brain MRI: median (95% CI) sNfL was 14.84 (9.9-42.5) pg/ml and 11.39 (8.9-13.2) pg/ml in patients without Gd⁺ lesions (p = .0144) and correlated with enhancing lesion volume (Pearson r = .36, p = .037) at the study baseline but not at week 52. Serum NfL did not correlate with the MRI BOD or disability measured by expanded disability status scale and 25-foot walk test.

CONCLUSION

In this small cohort of clinically stable IFN-treated Finnish MS patients, sNfL levels were similarly low in patients supplemented with high-dose vitamin D or placebo. Subclinical disease activity in MRI was associated with higher sNfL levels.

Lipid Profile Alterations during Fingolimod Treatment in Multiple Sclerosis Patients

Fingolimod reduces inflammatory activity in multiple sclerosis (MS) by acting as a functional antagonist of sphingosine 1-phosphate (S1P) receptors. It has been suggested that S1P might also contribute to the antiatherogenic effect of high-density lipoprotein (HDL). We conducted a retrospective observational study using data of 72 MS patients from two Finnish hospital districts to find out whether lipid profiles change during treatment with fingolimod. A mixed-effects model with patient as a random effect was used to analyze lipid profile alterations. We found a statistically significant elevation in both total cholesterol (0.12 mmol/L per year) and HDL (0.04 mmol/L per year) during a median follow-up of 12 months, while low-density lipoprotein (LDL) and triglycerides remained unchanged. Since the mean elevation observed in both lipid values seems to be modest, we suggest that routine lipid profile monitoring is unnecessary during fingolimod treatment in MS patients without pre-existing cardiovascular comorbidities. Graphical abstract.

Thalamic Atrophy Predicts 5-Year Disability Progression in Multiple Sclerosis

Purpose: Thalamus is among the first brain regions to become atrophic in multiple sclerosis (MS). We studied whether thalamic atrophy predicts disability progression at 5 years in a cohort of Finnish MS patients.

Methods: Global and regional brain volumes were measured from 24 newly diagnosed relapsing MS (RMS) patients 6 months after initiation of therapy and from 36 secondary progressive MS (SPMS) patients. The patients were divided into groups based on baseline whole brain parenchymal (BP) and thalamic atrophy. Standard scores (z scores) were computed by comparing individual brain volumes with healthy controls. A z score cutoff of −1.96 was applied to separate atrophic from normal brain volumes. The Expanded Disability Status Scale (EDSS), brain magnetic resonance imaging (MRI) findings, and relapses were assessed at baseline and at 2 years and EDSS progression at 5 years.

Results: Baseline thalamus volume predicted disability in 5 years in a logistic regression model (p = 0.031). At 5 years, EDSS was same or better in 12 of 18 patients with no brain atrophy at baseline but only in 5 of 18 patients with isolated thalamic atrophy [odds ratio (OR) (95% CI) = 5.2 (1.25, 21.57)]. The patients with isolated thalamic atrophy had more escalations of disease-modifying therapies during follow-up.

Conclusion: Patients with thalamic atrophy at baseline were at a higher risk for 5-year EDSS increase than patients with no identified brain atrophy. Brain volume measurement at a single time point could help predict disability progression in MS and complement clinical and routine MRI evaluation in therapeutic decision-making.

Trends and characteristics of infection-related hospital admissions in multiple sclerosis patients in Southwest Finland in 2009-2018

BACKGROUND

Multiple sclerosis (MS) patients are at increased risk for infections. The aim of this study was to investigate the trends in hospital admissions of patients with MS and to identify the factors predisposing to infection-related admissions.

METHODS

Hospital admissions with MS as a primary or an auxiliary diagnosis in the hospital district of Southwest Finland in 2009-2018 were searched and MS patients with infection admissions compared with other MS patients in the hospital district. Data were derived from hospital registries, patient charts and the Finnish MS register. Group comparisons were performed using Pearson´s chi-squared test, Fisher´s exact test or Wilcoxon rank sum test. Overdispersion-adjusted Poisson regression was used to analyze the annual admission numbers and multivariable logistic regression to examine the predictors of infection-related admissions.

RESULTS

1380 hospital admissions for 532 patients were identified. The annual number of admissions decreased by 8.9% annually (p<0.001). Proportion of infection-related admissions declined from 26.5% to 19.5% (p = 0.049). The patients with infection admissions were on average 8.2 years older (p<0.001), more often male (p<0.001), had on average 5.3 years longer disease duration (p<0.001), more disability (median EDSS 5.0 vs. 2.0; p<0.001), more often progressive disease (p<0.001) and more comorbidities (p = 0.006) than other MS patients. Disease modifying therapies (DMTs) were used less often by patients with infection admissions (p<0.001). Infection admissions were not associated with the number of recent relapses. In-hospital mortality was higher in the infection-related admissions (3.57% vs 0.29%; p<0.001). Only 14.3% of patients with over two infection admissions had a DMT during the study period.

CONCLUSION

Hospital admissions, with or without an infection, have become more infrequent in MS patients of Southwest Finland over the decade from 2009 to 2018. Infection-related admissions were associated with lesser use of DMTs, older age, male gender and disability.

Progressive dopaminergic defect in a patient with primary progressive multiple sclerosis

Dopamine has a modulatory role in a number of autoimmune diseases, but there are no published cases of longitudinal dopaminergic imaging in multiple sclerosis (MS). Here we report a patient with primary progressive multiple sclerosis (PPMS) who was scanned twice with brain dopamine transporter single photon emission computed tomography (SPECT) with an interval of four years. The results showed a loss of tracer binding that corresponded to a 4-7 fold steeper decline than in normal ageing. The finding points to a relevant role of nigrostriatal dopaminergic degeneration in the pathological process of PPMS.

Epstein-barr virus and multiple sclerosis risk in the finnish maternity cohort

OBJECTIVE

To determine whether maternal Epstein-Barr virus (EBV) IgG antibody levels are associated with risk of multiple sclerosis (MS) in the offspring.

METHODS

We conducted a prospective nested case-control study in the Finnish Maternity Cohort (FMC) with serum samples from >800,000 women collected during pregnancy since 1983. Cases of MS among offspring born between 1983 and 1991 were identified via hospital and prescription registries; 176 cases were matched to up to 3 controls (n = 326) on region and dates of birth, sample collection, and mother's birth. We used conditional logistic regression to estimate relative risks (RRs) and adjusted models for sex of the child, gestational age at sample collection, and maternal serum 25-hydroxyvitamin D and cotinine levels. Similar analyses were conducted among 1,049 women with MS and 1,867 matched controls in the FMC.

RESULTS

Maternal viral capsid antigen IgG levels during pregnancy were associated with an increased MS risk among offspring (RR_{top vs bottom quintile} = 2.44, 95% confidence interval [CI] = 1.20-5.00, p trend = 0.004); no associations were found between maternal EBV nuclear antigen 1 (EBNA-1), diffuse early antigen, or cytomegalovirus IgG levels and offspring MS risk. Among women in the FMC, those in the highest versus lowest quintile of EBNA-1 IgG levels had a 3-fold higher risk of MS (RR = 3.21, 95% CI = 2.37-4.35, p trend <1.11e-16). These associations were not confounded or modified by 25-hydroxyvitamin D.

INTERPRETATION

Offspring of mothers with high viral capsid antigen IgG during pregnancy appear to have an increased risk of MS. The increase in MS risk among women with elevated prediagnostic EBNA-1 IgG levels is consistent with previous results. ANN NEUROL 2019;86:436-442.

Thalamic Atrophy Without Whole Brain Atrophy Is Associated With Absence of 2-Year NEDA in Multiple Sclerosis

Purpose: To study which brain volume measures best differentiate early relapsing MS (RMS) and secondary progressive MS (SPMS) patients and correlate with disability and cognition. To test whether isolated thalamic atrophy at study baseline correlates with NEDA (no evidence of disease activity) at 2 years.

Methods: Total and regional brain volumes were measured from 24 newly diagnosed RMS patients 6 months after initiation of therapy and 2 years thereafter, and in 36 SPMS patients. Volumes were measured by SIENAX and cNeuro. The patients were divided into subgroups based on whole brain parenchyma (BP) and thalamic atrophy at baseline. Standard scores (z-scores) were computed by comparing individual brain volumes against healthy controls. A z-score cut-off of −1.96 was applied to separate atrophic from normal brain volumes. The Expanded Disability Status Scale (EDSS) and Symbol Digit Modalities Test (SDMT) were assessed at baseline and at 2 years. Differences in achieving NEDA-3, NEDA-4, EDSS progression, and SDMT change were analyzed between patients with no thalamic or BP atrophy and in patients with isolated thalamic atrophy at baseline.

Results: At baseline, 7 SPMS and 12 RMS patients had no brain atrophy, 8 SPMS and 10 RMS patients had isolated thalamic atrophy and 2 RMS and 20 SPMS patients had both BP and thalamic atrophy. NEDA-3 was reached in 11/19 patients with no brain atrophy but only in 2/16 patients with isolated thalamic atrophy (p = 0.012). NEDA-4 was reached in 7/19 patients with no brain atrophy and in 1/16 of the patients with isolated thalamic atrophy (p = 0.047). At 2 years, EDSS was same or better in 16/19 patients with no brain atrophy but only in 5/17 patients with isolated thalamic atrophy (p = 0.002). There was no significant difference in the EDSS, relapses or SDMT between patients with isolated thalamic atrophy and no atrophy at baseline.

Conclusion: Patients with isolated thalamic atrophy were at a higher risk for not reaching 2-year NEDA-3 and for EDSS increase than patients with no identified brain atrophy. The groups were clinically indistinguishable. A single measurement of thalamic and whole brain atrophy could help identify patients needing most effective therapies from early on.

Multiple sclerosis epidemiology in Finland: Regional differences and high incidence

OBJECTIVES

Studies on the east-west gradient of multiple sclerosis (MS) are scarce. In Finland, epidemiological differences have been only partially elucidated, but the MS risk is high, and it has been claimed that the occurrence follows a longitudinal gradient. In this register-based study, we updated the MS epidemiology in southwest Finland (SwF) and compared it to the easternmost hospital district, North Karelia (NK), for which no previous data exist.

MATERIALS AND METHODS

Patients with ICD-10 code G35 were identified from hospital district administrative data. Patient records were reviewed to include only cases with a definitive diagnosis. Incidence period covered 5 years (2012-2016), and the prevalence date was December 31, 2016. Results were standardized using the direct method.

RESULTS

A total of 1184 persons had MS in SwF and 253 persons in NK at the end of 2016. The prevalence was 280/100 000 (95% CI 264-296) in SwF and 168/100 000 (95% CI 148-190) in NK (age-standardized for the European standard population 2013). During the incidence period, 211 new MS diagnoses were made in SwF and 49 in NK. The annual age-standardized (ESP 2013) incidence was 12.1/100 000 person-years (95% CI 10.5-13.8) in SwF and 8.6/100 000 person-years (95% CI 6.4-11.2) in NK in the age-group 10-69 years.

CONCLUSIONS

There are regional differences in MS epidemiology in Finland, possibly related to demographic, social, and genetic circumstances, but the retrospective nature and limited sample size of this study might introduce some uncertainty to the calculations. SwF is a region with a globally very high risk for MS.

Adult hospital admissions associated with multiple sclerosis in Finland in 2004-2014

INTRODUCTION

Treatment of multiple sclerosis (MS) has developed significantly and several new immunotherapeutic drugs have become available in Finland since 2004. We studied whether this is associated with changes in hospital admission frequencies and healthcare costs and whether admission rates due to infection have increased.

METHODS

The national Care Register for Health Care was searched for all discharges from neurological, medical, surgical, neurosurgical and intensive care units with MS as a primary diagnosis or an auxiliary diagnosis for primary infection diagnosis in 2004-2014. Only patients ≥16 years of age were included.

RESULTS

We identified 12,276 hospital admissions for 4296 individuals. The number of admissions declined by 4.6% annually (p = .0024) in both genders. Proportion of admissions with an infection as the primary diagnosis increased but no change in their frequency was found. They were longer than admissions with MS as the primary diagnosis and were associated with increased in-hospital mortality. The annual aggregate cost of hospital admissions declined by 51% during the study period.

CONCLUSIONS

This study shows that hospital admission rates and costs related to MS hospital admissions have markedly declined from 2004 to 2014 in Finland, which coincides with an increase in the use of disease-modifying therapies. Key message Hospital admission rates and costs related to MS hospital admissions have markedly declined from 2004 to 2014 in Finland. Proportion of admission related to infection has increased and they are associated with longer hospitalizations and increased in-hospital mortality pointing out the importance of infection prevention.

Efficacy and safety outcomes in vitamin D supplement users in the fingolimod phase 3 trials

BACKGROUND

Low serum levels of 25-hydroxyvitamin D have been associated with worse outcomes in multiple sclerosis (MS) patients treated with interferon-beta. Association of vitamin D nutrition on the outcomes of other MS therapies has been studied less.

OBJECTIVE

Whether patients in the phase 3 fingolimod trials using vitamin D supplements have better clinical, MRI and safety outcomes than non-users.

MATERIALS AND METHODS

Pooled data from phase 3 FREEDOMS trials was analyzed post hoc. Vitamin D use was defined as 'non-users' (n = 562), 'casual users' (n = 157) and 'daily users' (usage 100% time in the study, n = 110).

RESULTS

Expanded Disability Status Scale change from baseline to month 24, and annual relapse rate and proportion of patients with relapses were similar across the vitamin D user groups. Proportion of patients free of new/enlarging T2 lesions significantly favored vitamin D 'daily users' versus 'non-users'. Mean number of lesions were lower and proportion of patients free of gadolinium-enhanced T1-lesions were higher in the 'daily users'. At month 12, percent brain volume change was significantly lower in the 'daily users' versus 'non-users' and remained low at month 24 (non-significant). Incidence of depression was lower for vitamin D 'daily users' (non-significant).

CONCLUSIONS

We observed improved MRI outcomes on percent brain volume change and proportion of patients free of new/enlarging T2 lesions, and a trend of less depression in the 'daily users' of vitamin D supplement in patients in the FREEDOMS trials.

Epidemiology of Guillain-Barré syndrome in Finland 2004-2014

At total mean incidence of 0.84–1.1/100,000 the occurrence of Guillain‐Barré syndrome (GBS) is reported to be low in Finland compared to other Caucasian populations. However, a recent study from Southwestern Finland reported an incidence of 1.82/100,000 which is comparable to other Caucasian populations. We analyzed discharge data covering the years 2004 through 2014 on all neurological admissions in all Finnish university and central hospitals with a primary diagnosis of GBS. A total of 989 admissions due to GBS (917 individuals) were identified. The standardized (European population) annual incidence rate was 1.70/100,000 person‐years (95% confidence interval 1.60–1.81). GBS incidence had an increasing trend with age. The likelihood of GBS was higher among girls and adolescent women than boys and men of same age (male:female incidence rate ratio [IRR] 0.56), while in the older age groups (>19 years) the occurrence of GBS was higher among males than females (male:female IRR 1.59). The incidence of GBS remained stable during the study period. There was no seasonal variation in GBS admission frequencies (p = 0.28). No significant effect of the 2009–2010 H1N1 influenza or vaccination against it for GBS occurrence was observed. We suggest that GBS is as common, and has similar age‐distribution in Finland as in other European countries. Sex‐associated susceptibility for GBS appears to be different in children‐adolescents and adults.

25-Hydroxyvitamin D deficiency and risk of MS among women in the Finnish Maternity Cohort

OBJECTIVE

To determine whether and to what extent vitamin D deficiency is associated with multiple sclerosis (MS) risk.

METHODS

We conducted a prospective nested case-control study among women in the Finnish Maternity Cohort (FMC). The FMC had 1.8 million stored serum samples taken during the pregnancies of over 800,000 women at the time of this study. Through linkages with hospital and prescription registries, we identified 1,092 women with MS diagnosed between 1983 and 2009 with at least 1 serum sample collected prior to date of MS diagnosis; ≥2 serum samples were available for 511 cases. Cases were matched to up to 3 controls (n = 2,123) on date of birth (±2 years) and area of residence. 25-Hydroxyvitamin D (25[OH]D) levels were measured using a chemiluminescence assay. We used conditional logistic regression adjusted for year of sample collection, gravidity, and parity to estimate relative risks (RRs) and 95% confidence intervals (CIs).

RESULTS

A 50 nmol/L increase in 25(OH)D was associated with a 39% reduced risk of MS (RR 0.61, 95% CI 0.44-0.85), p = 0.003. Women with 25(OH)D levels <30 nmol/L had a 43% higher MS risk (RR 1.43, 95% CI 1.02-1.99, p = 0.04) as compared to women with levels ≥50 nmol/L. In women with ≥2 samples, MS risk was 2-fold higher in women with 25(OH)D <30 nmol/L as compared to women with 25(OH)D ≥50 nmol/L (RR 2.02, 95% CI 1.18-3.45, p = 0.01).

CONCLUSIONS

These results directly support vitamin D deficiency as a risk factor for MS and strengthen the rationale for broad public health interventions to improve vitamin D levels.

Vitamin D Status During Pregnancy and Risk of Multiple Sclerosis in Offspring of Women in the Finnish Maternity Cohort

IMPORTANCE

Vitamin D has been associated with a decreased risk of multiple sclerosis (MS) in adulthood; however, some, but not all, previous studies have suggested that in utero vitamin D exposure may be a risk factor for MS later in life.

OBJECTIVE

To examine whether serum 25-hydroxyvitamin D (25[OH]D) levels in early pregnancy are associated with risk of MS in offspring.

DESIGN, SETTING, AND PARTICIPANTS

Prospective, nested case-control study in the Finnish Maternity Cohort conducted in May 2011. We identified 193 individuals with a diagnosis of MS before December 31, 2009, whose mothers are in the Finnish Maternity Cohort and had an available serum sample from the pregnancy with the affected child. We matched 176 cases with 326 controls on region of birth in Finland, date of maternal serum sample collection, date of mother's birth, and date of child's birth.

MAIN OUTCOMES AND MEASURES

Maternal serum 25(OH)D levels were measured using a chemiluminescence assay. The risk of MS among offspring and association with maternal 25(OH)D levels were the main outcomes. Conditional logistic regression was used and further adjusted for sex of the child, gestational age at the time of sample collection, and season of sample collection to estimate the relative risks and 95% CIs.

RESULTS

Of the 193 cases in the study, 163 were female. Of the 331 controls in the study, 218 were female. Seventy percent of serum samples were collected during the first trimester of pregnancy. The mean (SD) maternal vitamin D levels were in the insufficient vitamin D range, but higher in maternal control than case samples (15.02 [6.41] ng/mL vs 13.86 [5.49] ng/mL [to convert to nanomoles per liter, multiply by 2.496]). Maternal vitamin D deficiency (25[OH]D levels <12.02 ng/mL) during early pregnancy was associated with a nearly 2-fold increased risk of MS in the offspring (relative risk, 1.90; 95% CI, 1.20-3.01; P = .006) compared with women who did not have deficient 25(OH)D levels. There was no statistically significant association between the risk of MS and increasing serum 25(OH)D levels (P = .12).

CONCLUSIONS AND RELEVANCE

Insufficient maternal 25(OH)D during pregnancy may increase the risk of MS in offspring.

Risk of osteoporotic fractures in multiple sclerosis patients in southwest Finland

OBJECTIVES

Increased risk of osteoporotic fractures in multiple sclerosis (MS) patients compared with general population has been reported. The purpose of this study was to assess the risk of osteoporotic and other low-energy fractures in an MS cohort from a large hospital district in southwest Finland. Age-adjusted total and gender-specific prevalence for definite MS per 100 000 in a population of 472 139 was calculated as a point prevalence in December 31, 2012.

MATERIALS AND METHODS

Patients with MS and comorbid fractures were identified by searching for ICD-9 and ICD-10 codes during a period from 2004 to 2012 from hospital administrative data in Turku University Hospital (TYKS) in southwest Finland Case ascertainment was performed by review of medical records. Osteoporotic fracture was defined as a low-energy fracture of the pelvis, hip, femur, tibia, humerus, collar bone, ulna/radius, vertebrae, or rib. The control population was a 10-fold age- and gender-matched population.

RESULTS

The point prevalence (N 1004) of MS was 212.6/10⁵ (CI 199.5-225.8) in December 31, 2012. A total of 100 (9.9%) of 1004 confirmed MS cases experienced at least one fracture during the study period. Relative risks (RRs) for all fractures (1.33, 95% CI 1.10-1.60) and osteoporotic fractures (1.50, 95% CI 1.18-1.90) were significantly increased in patients with MS compared with controls. In particular, RRs for hip fractures (5.00, 95% CI 2.96-8.43) and fractures of humerus (2.36, 95% CI 1.32-4.42) were elevated in patients with MS vs controls.

CONCLUSIONS

We observed high prevalence of MS in southwest Finland and confirmed increased age-adjusted comorbid risk for osteoporotic fractures and other low-energy fractures compared with individually matched controls.

Comorbid epilepsy in Finnish patients with adult-onset Huntington's disease

Background

Seizures are common in juvenile Huntington’s disease (HD), but considered to be rare in adult-onset HD. We studied the occurrence of epilepsy and seizures in a nationwide cohort of Finnish patients with adult-onset HD.

Methods

Patients with HD and their diagnoses of epilepsy or seizures were identified by a search into a nationwide registry. Cases were verified in a subsequent review of patient charts.

Results

Three out of 114 HD patients alive on prevalence date had been diagnosed with epilepsy giving a prevalence of 2.6 % (95 % CI, 0.6–7.5). In addition, one patient with a single unprovoked seizure, one patient with a medication-induced seizure and two patients with transient nonspecific attacks were identified. Epilepsy was not associated with clinical severity of HD and seizures were controlled with antiepileptic medications (AEDs). Generalized tonic-clonic seizures (GTCs) were the most common seizure type.

Conclusions

Prevalence of epilepsy is similar in patients with adult-onset HD compared to general population. Seizures are easily controlled with AEDs.

Vitamin D3 administration to MS patients leads to increased serum levels of latency activated peptide (LAP) of TGF-beta

BACKGROUND

Deficiency of vitamin D is an environmental risk factor for MS. Vitamin D has immunomodulatory effects, including promotion of T-cell differentiation into T-regulatory cells, which produces regulatory cytokines including TGF-β. Increasing serum vitamin D levels have been associated with decreased disease activity in MS patients, but there are only few studies concerning the immunological effects of vitamin D supplementation in MS. In this study we investigated the effect of weekly supplementation of vitamin D3 or placebo on serum levels of multiple cytokines in patients with relapsing remitting MS.

METHODS

The study was conducted on the patient cohort of the Finnish Vitamin D study. All patients were using IFN-beta-1b and were randomized to add-on treatment with either cholecalciferol 20,000 IU/week or placebo. Concentrations of LAP (TGF-β), INF-γ, IL-17A, IL-2, IL-10, IL-9, IL-22, IL-6, IL-13, IL-4, IL-5, IL-1β and TNF-α were determined at screening and at 12 months using commercial fluorescent bead immunoassay kits.

RESULTS

LAP (TGF-β) levels increased significantly in the vitamin D treated group from a mean of 47 (SE 11) pg/ml to 55 (SE 14) pg/ml in 12 months (p-value=0.0249). Placebo treatment had no significant effect on LAP levels. The levels of the other cytokines did not change significantly in either group.

CONCLUSIONS

We showed increased serum latency activated peptide (LAP) of TGF-β levels in MS patients treated with vitamin D3. The immune regulatory effects of TGF-beta may play a role in the improved MRI outcomes that we observed earlier in the vitamin D treated group of patients.

[Respiratory disturbance during sleep induced by vagus nerve stimulator]

Vagus nerve stimulation can be used in parallel with drug therapy as adjuvant therapy for severe epilepsy. In approximately half of the patients the number of seizures decreases by at least 50%. The most common adverse effects reported for the therapy include mild laryngeal and upper respiratory tract symptoms and dysfunctions, and in some cases, also development of respiratory disturbances during sleep. We describe two patients in whom vagus nerve stimulation induced sleep apnea. The problem was resolved by changing the settings of the stimulator. Sleep apnea syndrome should be kept in mind when planning vagus nerve stimulation therapy and monitoring the response to therapy.

[Magnetic resonance imaging of the brain in the monitoring of immune therapy of multiple sclerosis]

Magnetic resonance imaging of the brain is currently the most sensitive method in detecting the lesions caused by multiple sclerosis. Assessment of the immunological treatment response used in the treatment of multiple sclerosis should be based on the clinical picture and brain MRI. T2-, flair- and T1-biased images, gadolinium enhancement and assessment of atrophy are required for MRI monitoring. In the first-line immune therapy MRI is taken at 6 to 12 months after starting the drug therapy, in fingolimod therapy after 6 to 12 months and 1 to 2 years, respectively, and in alemtuzumab and natalizumab therapy after one and two years.

The incidence and triggers of adult-onset Guillain-Barré syndrome in southwestern Finland 2004-2013

BACKGROUND AND PURPOSE

A Swiss study recently reported surgery as a potential risk factor for developing Guillain-Barré syndrome (GBS). It was sought to establish this in the Finnish adult population.

METHODS

Persons over 16 years of age who received a diagnosis of GBS in 2004-2013 were identified from the patient register of Turku University Hospital and their patient records were analyzed to identify possible triggers.

RESULTS

A cohort of 69 adult patients with GBS (63.8% men) was identified giving an annual incidence of 1.82/100,000. Of these, four (5.8%) had experienced a surgical procedure during the preceding 6 weeks with a relative risk of 6.28 (95% confidence interval 4.15-9.47, P < 0.001) compared with the general study population or a risk of 1.25/100,000 operations. No difference between genders was found. Only two (2.9%) patients had received a vaccination [one against seasonal influenza (P = 0.888) and one against pandemic influenza (Pandemrix(®), GlaxoSmithKline Biologicals, Rixensart, Belgium, relative risk 2.85, 95% confidence interval 1.27-6.38, P = 0.011)] during the preceding 6 weeks. The most common GBS triggers identified were respiratory tract infections in 30 cases (43.5%) and gastroenteritis in 16 cases (23.2%) whilst two patients (2.9%) had had both.

CONCLUSIONS

The overall incidence of GBS in the adult population of southwestern Finland was similar to previous studies worldwide and the most common triggers were respiratory tract infections and gastroenteritis. Surgery was a rare risk factor and of vaccinations only the one against pandemic influenza raised the risk of GBS.

[Cerebral nocardiosis as surprising cause of a convulsive seizure]

Underlying a convulsive seizure of an adult patient many different types of cause can be detected, such as alcohol withdrawal, disturbance of the cerebral circulation, cerebral hemorrhage, brain tumor, metabolic disturbances, drugs or infection. In connection with severe central nervous system infections, such as brain abscesses, convulsive seizures occur in approximately one out of five patients. A patient with brain abscess may be nonfebrile and have normal values of inflammatory markers. The diagnosis is based on contrast-enhanced CT scanning or magnetic resonance imaging of the brain. Even surgical sampling is often necessary. In our patient, a rare nocardia-induced brain abscess turned out to be the cause of recurrent convulsive seizures.

[Progressive multifocal leukoencephalopathy as a complication of natalizumab therapy]

Natalizumab medication used in the treatment of active relapsing-remitting multiple sclerosis is associated with a risk of contracting progressive multifocal leukoencephalopathy (PML). Current risk of the PML disease in connection with natalizumab therapy in multiple sclerosis patients is 2.77/1,000. By December 2012, more than 108,000 multiple sclerosis patients worldwide have received natalizumab therapy. There are 350 multiple sclerosis patients receiving natalizumab in Finland. We describe the first one of the two Finnish multiple sclerosis patients having so far been diagnosed with PML disease as a complication of natalizumab therapy.

A randomised, double blind, placebo controlled trial with vitamin D3 as an add on treatment to interferon β-1b in patients with multiple sclerosis

OBJECTIVES

To study the safety and efficacy of vitamin D3 as an add on therapy to interferon β-1b (IFNB) in patients with multiple sclerosis (MS).

METHODS

1 year, double blind, placebo controlled, randomised study in 66 MS patients. The primary outcomes were T2 burden of disease (BOD) on MRI scans, proportion of patients with serum levels of 25-hydroxyvitamin D (25(OH)D) ≥85 nmol/l or intact parathyroid hormone (PTH) ≤20 ng/l, and number of adverse events. Secondary outcomes were number of MRI enhancing T1 lesions and new T2 lesions, annual relapse rate, changes in the Expanded Disability Status Scale score, timed 25 foot walk test and timed 10 foot tandem walk tests.

RESULTS

Median change in BOD was 287 mm(3) in the placebo group and 83 mm(3) in the vitamin D group (p=0.105). Serum levels of 25(OH)D increased from a mean of 54 (range 19-82) nmol/l to 110 (range 67-163) nmol/l in the vitamin D group. 84% of patients reached a serum 25(OH)D level >85 nmol/l in the vitamin D group and 3% in the placebo group (p<0.0001). Patients in the vitamin D group showed fewer new T2 lesions (p=0.286) and a significantly lower number of T1 enhancing lesions (p=0.004), as well as a tendency to reduced disability accumulation (p=0.071) and to improved timed tandem walk (p=0.076). There were no significant differences in adverse events or in the annual relapse rate.

CONCLUSION

Vitamin D3 add on treatment to IFNB reduces MRI disease activity in MS.

TRIAL REGISTRATION NUMBER

EudraCT number 2007-001958-99 and ClinicalTrialsGov number NCT01339676.

C-reactive protein and seizures in focal epilepsy: a video-electroencephalographic study

PURPOSE

  C-reactive protein (CRP) has been studied extensively in many noninflammatory neurologic conditions, but there has been little study of CRP in the context of seizures or epilepsy. The purpose of this study was to examine CRP concentrations in patients with refractory focal epilepsy who were undergoing video-electroencephalography (EEG) monitoring compared with healthy controls, and CRP change during 24 h after a seizure.

METHODS

  CRP levels were measured in serum at the onset of video-EEG recording (CRP-0h) and at 3, 6, 12, and 24 h after index seizure (the first verified localized-onset seizure) in 31 patients during inpatient video-EEG monitoring by using high sensitivity measurement of CRP concentration. The patients were categorized into two groups: temporal lobe epilepsy (TLE; n = 15) and extratemporal lobe epilepsy (XLE; n = 16). Eighty healthy volunteers served as controls.

KEY FINDINGS

  CRP-0h concentration was significantly higher in patients with refractory focal epilepsy than in controls (3.5 vs. 0.7 mg/ml, p < 0.001). All five patients with elevated CRP-0h (>mean + 2 standard deviations in controls) had TLE (vs. none in XLE; p = 0.018). Index seizure type was associated with CRP increase from baseline to maximum level after index seizure (p = 0.005). The most important predictor of increase in CRP level was secondarily generalized tonic-clonic seizure (SGTCS; p = 0.030).

SIGNIFICANCE

  The higher baseline levels in patients with epilepsy compared with healthy controls demonstrates that CRP concentrations are also affected in refractory epilepsy. Our data suggest that SGTCS stimulates CRP production. These results emphasize the association between inflammation and refractory epilepsy.

[Paroxysmal feeling of suffocation during sleep--a diagnostic challenge]

Our patient suffered from nocturnal awakenings due to paroxysmal feelings of suffocation for three years. He was extensively examined at the community health centre and at the departments of neurology, psychiatry, oral diseases and respiratory medicine of the district hospital and the university hospital. The clinical hunch of the night nurses of the department of respiratory medicine and video EEG monitoring recommended by the sleep disorders team eventually revealed the real cause of the patient's symptoms.

Characterization of CD4+ T cells specific for glutamic acid decarboxylase (GAD65) and proinsulin in a patient with stiff-person syndrome but without type 1 diabetes

BACKGROUND

Glutamic acid decarboxylase (GAD) is a rate-limiting enzyme in the synthesis of gamma-amino butyric acid (GABA) and an important autoantigen both in patients with type 1 diabetes (T1D) and stiff-person syndrome (SPS). Autoantibodies (GADA) to the 65-kDa isoform of GAD are a characteristic feature in both diseases. Approximately 30% of patients with SPS develop diabetes, yet, it is unclear to which extent co-existing autoimmunity to GAD65 and other islet autoantigens determines the risk of developing T1D.

METHODS

In this study, we monitored CD4+ T-cell responses to GAD65 and proinsulin in a patient with SPS who remained normoglycaemic during the 46-month follow-up.

RESULTS

Fluctuating but persistent T-cell reactivity to GAD65 was identified, as well as T-cell reactivity to proinsulin at one time point. The majority of the T-cell clones isolated from the patient with SPS produced high levels of Th2 cytokines (IL-13, IL-5 and IL-4). We also examined levels of GADA, insulin and IA-2 autoantibodies, and epitope specificity of GADA. In both serum and cerebrospinal fluid (CSF), GADA levels were high, and GADA persisted throughout the follow-up. Despite T-cell reactivity to both GAD65 and proinsulin, autoantibodies to other islet autoantigens did not develop.

CONCLUSIONS

Further follow-up will determine whether the beta-cell autoimmunity observed in this patient will eventually lead to T1D.

Expression of LIF and LIF receptor beta in Alzheimer's and Parkinson's diseases

BACKGROUND

Signaling through the leukemia inhibitory factor (LIF) receptor (LIFR) is crucial for nervous system development. There are few studies concerning the expression of LIF and LIFR in normal and degenerating adult human brain.

OBJECTIVES

To study the expression of LIF and LIFR in Alzheimer's disease (AD), Parkinson's disease (PD), and control brains.

PATIENTS AND METHODS

LIF and LIFR mRNA copy numbers were determined by quantitative real-time RT-PCR from four brain regions of 34 patients with AD, 40 patients with PD, and 40 controls. Immunohistochemistry was performed in seven PD and in four AD patients and in seven normal controls.

RESULTS

In general, the LIF copy numbers were 1 log higher than the LIFR copy numbers. In the AD brains, LIF expression was higher than in the controls in the hippocampus and in the temporal cortex, and in the PD brains in the hippocampus and in the anterior cingulated cortex. Expressions of LIF and LIFR in different brain regions were opposite except for the AD hippocampus and PD anterior cingulated cortex, where the expression patterns were parallel.

CONCLUSIONS

Co-operative expression of LIF and LIFR in AD hippocampus and PD anterior cingulated cortex may indicate a role for LIF in neuronal damage or repair in these sites.

T2-weighted high-intensity signals in the basal ganglia as an interesting image finding in Unverricht-Lundborg disease

We conducted a search for white matter changes (WMCs) in 13 Unverricht-Lundborg disease patients and compared the prevalence of WMCs in these patients to age-matched long-term epileptics and healthy controls. ULD patients had significantly more T2-weighted high-intensity signals on MRI than control subjects, due to the increased prevalence of these signals in the basal ganglia. Interestingly, ULD patients with the basal ganglia changes were overweight. Basal ganglia T2-weighted high-intensity signals are novel findings in ULD.

A longitudinal study of serum 25-hydroxyvitamin D and intact parathyroid hormone levels indicate the importance of vitamin D and calcium homeostasis regulation in multiple sclerosis

BACKGROUND

Past sun exposure and vitamin D3 supplementation have been associated with a reduced risk of multiple sclerosis (MS). There are no previous longitudinal studies of vitamin D in MS.

OBJECTIVES

To compare regulation of vitamin D and calcium homeostasis between patients with MS and healthy controls. To study the correlation of parameters of vitamin D metabolism with MS activity.

METHODS

We measured 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), calcium, phosphate, magnesium, chloride, alkaline phosphatase, albumin and thyroid stimulating hormone in serum every 3 months and at the time of relapse over 1 year in 23 patients with MS and in 23 healthy controls. MRI burden of disease and T2 activity were assessed every 6 months.

RESULTS

Vitamin D deficiency (S-25(OH)D < or = 37 nmol/l) was common, affecting half of the patients and controls at some time in the year. Seasonal variation of 25(OH)D was similar in patients and controls, but 25(OH)D serum levels were lower and intact PTH (iPTH) serum levels were higher during MS relapses than in remission. All 21 relapses during the study occurred at serum iPTH levels > 20 ng/l (2.2 pmol/l), whereas 38% of patients in remission had iPTH levels < or = 20 ng/l. Patients with MS had a relative hypocalcaemia and a blunted PTH response in the winter. There was no correlation between serum 25(OH)D and MRI parameters.

CONCLUSIONS

The endocrine circuitry regulating serum calcium may be altered in MS. There is an inverse relationship between serum vitamin D level and MS clinical activity. The role of vitamin D in MS must be explored further.

Downregulation of VLA-4 on T cells as a marker of long term treatment response to interferon beta-1a in MS

We determined longitudinally the expression of a panel of adhesion molecules on T cells and soluble ICAM-1, VCAM-1 and tumor necrosis factor apoptosis inducing ligand (TRAIL) in serum during first year of the PRISMS Study with IFNbeta1a in MS. Clinical data and quantitative MRI data were available for 4 years. VLA-4 was down-regulated on T cells and VCAM-1 was up-regulated in serum during the first 3 to 6 months of therapy in patients with favorable long-term treatment response (EDSS progression </=1.0 in 4 years). Short disease duration and low EDSS were clinical pre-treatment characteristics related to good long-term response to therapy.

Hyaluronate receptor (CD44) and integrin alpha4 (CD49d) are up-regulated on T cells during MS relapses

A longitudinal study of peripheral blood T cell adhesion molecule expression was performed in 24 relapsing-remitting MS patients. There were 15 relapses in 11 patients during 15 months of observation. In comparison with remission, expression of hyaluronate receptor (CD44) was highly significant, and expression of integrin alpha4 (CD49d, VLA-4) significantly up-regulated during relapses. CD44 and CD49d are putative activity markers and CD44 a potential novel therapeutic target in MS.

25-Hydroxyvitamin D levels in serum at the onset of multiple sclerosis

Past sun exposure and vitamin D supplementation have been associated with a reduction in the risk of MS. We measured the serum concentration of 25-hydroxyvitamin D (25[OH]D) at the time of MS diagnosis in 40 MS patients and 40 controls. We found no difference in the serum levels of 25(OH)D between MS patients and controls when all samples or samples obtained during winter months were compared, but MS patients had significantly lower serum 25(OH)D concentrations in June to September than the controls. The vitamin D stores were adequate for bone metabolism (> 37 nmol/L) in 70% of MS patients throughout the year and within the hypovitaminosis level (< 37 nmol/L) in 30% of MS patients at some time of the year. During MS-relapses, 25(OH)D levels were lower than in remission, but mostly within the reference range observed in relation with normal bone metabolism. We conclude that the vitamin D stores in most MS patients are adequate for their normal bone metabolism. However, lower vitamin D levels during MS relapses than in remission suggest that vitamin D could be involved in the regulation of the clinical disease activity of MS. The optimal serum levels of vitamin D for the regulation of immune responses remain to be determined.

High sensitivity measurement of CRP and disease progression in multiple sclerosis

The authors measured serum C-reactive protein (CRP) serially in patients with multiple sclerosis (MS) who participated the PRISMS study using a high-sensitivity technique. CRP values were similar in patients with MS and in healthy controls but higher during MS relapses than in remission (p = 0.010). CRP levels were lower during treatment with high-dose interferon beta 1a than placebo (p = 0.035) and higher during first 12 months of study in patients who progressed by year 4 compared with stable patients (p = 0.007).

Induction of postnatal schwann cell death by the low-affinity neurotrophin receptor in vitro and after axotomy

Schwann cells express the low-affinity neurotrophin receptor (p75), but no role for either the neurotrophins or their cognate receptors in Schwann cell development has been established. We have found that Schwann cells isolated from postnatal day 1 (P1) or P2 mice that were p75-deficient exhibited potentiated survival compared to wild-type cells after growth factor and serum withdrawal. There was, however, no disparity in the survival of p75-deficient and wild-type Schwann cells isolated at embryonic day 15, suggesting that the death-inducing effects of p75 are developmentally regulated. A comparable degree of cell death was also observed in the sciatic nerves of both wild-type and p75-deficient mice at P1. However, 24 hr after axotomy, there was a 13-fold increase in the percentage of apoptotic nuclei in the distal nerve stumps of the transected sciatic nerves of neonatal wild-type but not p75-deficient mice. The expression of both the p75 and nerve growth factor (NGF) genes was upregulated after axotomy in neonatal wild-type nerves. Collectively, these results suggest that NGF-mediated activation of p75 is likely to be an important mediator of Schwann cell apoptosis in the context of peripheral nerve injury.

Treatment of experimental autoimmune encephalomyelitis with antisense oligonucleotides against the low affinity neurotrophin receptor

Upregulated expression of the low-affinity neurotrophin receptor (p75) in the central nervous system (CNS) during experimental autoimmune encephalomyelitis (EAE) has recently been demonstrated. To investigate whether p75 plays a role in disease pathogenesis, we adopted a gene therapy approach, utilizing antisense oligonucleotides to downregulate p75 expression during EAE. Phosphorothioate antisense oligonucleotides (AS), nonsense oligonucleotides (NS) or phosphate buffered saline (PBS) were injected daily for 18 days after immunization of SJL/J (H-2s)-mice with myelin proteolipid protein (PLP) peptide 139-151. In the AS group, there was a statistically significant reduction in both the mean maximal disease score (1.85 in the AS, 2.94 in the NS and 2.75 in the PBS-groups, respectively, P < 0.025) and in the cumulative disease incidence ( approximately 60% in the AS group and approximately 90% in the control groups). Histological and immunohistochemical analysis showed reduced inflammation and demyelination, as well as reduced p75 expression at the blood-brain barrier (BBB) in the AS-treated mice in comparison with both control groups. There was no difference, however, in p75 expression on neural cells within the CNS between the three groups of mice. We conclude that p75 could play a proactive role in the pathogenesis of EAE and may exert its effect at the level of the BBB.

Nerve growth factor signaling through p75 induces apoptosis in Schwann cells via a Bcl-2-independent pathway

Apoptosis is involved in the regulation of Schwann cell numbers during normal development and after axonal damage, but the molecular regulation of Schwann cell death remains unknown. We have used stably transfected rat Schwann cell lines to study the potential roles of nerve growth factor (NGF), the antiapoptotic protein Bcl-2 and the cytokine response modifier A (CrmA) in modulating Schwann cell death in vitro. Bcl-2 inhibited Schwann cell apoptosis induced by survival factor withdrawal, whereas CrmA did not. In contrast, Bcl-2-transfected Schwann cells were susceptible to apoptosis in response to exogenous NGF, whereas CrmA-expressing cell lines were resistant. Demonstration of high levels of the low-affinity neurotrophin receptor p75 but not the high-affinity TrkA receptor on the Bcl-2-transfected cell lines suggested that the NGF-induced killing was mediated by p75. This was confirmed by resistance of Schwann cells isolated from p75 knockout mice to the NGF-induced cell death. Nerve growth factor also promoted the death of wild-type mouse and rat Schwann cells in the absence of survival factor withdrawal. Endogenous Bcl-2 mRNA was expressed by wild-type Schwann cells in all conditions that promoted survival but was downregulated to undetectable levels after survival factor withdrawal. In conclusion, our results demonstrate the existence of two separate pathways that expedite apoptosis in Schwann cells: a Bcl-2-blockable pathway initiated on loss of trophic support, and a Bcl-2-independent, CrmA-blockable pathway mediated via the p75 receptor.