A highly challenging balance training intervention for people with multiple sclerosis: a feasibility trial

BACKGROUND

Balance training interventions with a gradual progression of difficulty and highly challenging tasks designed specifically for people with multiple sclerosis (MS) are rare. The objective was to adapt a balance training intervention originally developed for Parkinson's disease through a co-design process and then conduct a pilot trial in MS to evaluate the feasibility of a large, full-scale study.

METHODS

Twelve people with MS with mild to moderate overall MS-disability were included in this single-group feasibility trial. Participants received one-hour training sessions twice or three times weekly for 10 weeks. The assessment included tests of physical and cognitive functioning and patient-reported quality of life-related outcomes. Data on feasibility aspects were collected at baseline and follow-up assessments and three times during the intervention period to inform the recruitment process, as well as to monitor retention and inclusion rates, study procedures, intervention delivery, and dynamic changes in the selected potential outcome measures. Progression criteria were used to determine whether to proceed to a full-scale trial. Descriptive statistics were used to present the data.

RESULTS

Out of six progression criteria, only retention and attendance at training sessions were not met. Reasons reported for not completing the intervention period mainly depended on external circumstances beyond the control of the study. In contrast, study procedures, intervention delivery, and intervention content (progression, adjustment, and control of challenge level of exercises) were considered feasible for a future, full-scale trial. The Mini-BESTest, which was used for the assessment of balance control, was considered suitable as the primary outcome in a full-scale trial with no ceiling or floor effects. Further, the Mini-BESTest showed a positive trend in outcome response with a median difference of 3.5 points between baseline and follow-up assessments. The power calculation performed suggests a feasible number of participants for recruitment.

CONCLUSIONS

Overall trial aspects and intervention delivery were deemed feasible for a full-scale trial, but adjustments are needed to increase retention and attendance.

High-intensity resistance training in people with multiple sclerosis experiencing fatigue: A randomised controlled trial

BACKGROUND

Exercise studies including only fatigued persons with multiple sclerosis (PwMS) with fatigue as primary endpoint are lacking.

OBJECTIVE

To evaluate the effects of high-intensity resistance training (HIRT) on self-reported fatigue in fatigued PwMS in a single center randomised controlled trial.

METHODS

We recruited 71 PwMS scoring ≥ 53 on the Fatigue Scale for Motor and Cognitive Functions (FSMC), who were randomised 1:1 to either twice (group A) or once (group B) weekly supervised HIRT for twelve weeks. A non-randomised FSMC score-matched group (n=69) served as non-intervention control.

RESULTS

Between HIRT-group differences were non-significant for primary and most secondary endpoints. Mean difference in FSMC score (95% confidence intervals) was -10.9 (-14.8; -6.9) in group A and -9.8 (-13.2; -6.3) in group B. Corresponding values for combined HIRT groups vs non-intervention control were -10.3 (-12.9; -7.7) and 1.5 (-0.6;3.6), respectively, p<0.001. Secondary endpoints also improved in both HIRT groups, though only Hospital Anxiety and Depression Scale anxiety and MS Impact Scale-29 psychological subscales significantly favoured the twice a week HIRT (group A). As an exploratory endpoint, changes in plasma inflammatory protein markers were associated with reduced FSMC scores in the pooled material.

CONCLUSION

The finding that HIRT in fatigued PwMS leads to clinically relevant reductions in self-reported fatigue, associated with changes in plasma inflammatory protein levels, provide evidence for recommending HIRT for fatigued PwMS.

Current and emerging disease-modulatory therapies and treatment targets for multiple sclerosis

The treatment of multiple sclerosis (MS), the most common chronic inflammatory, demyelinating and neurodegenerative disease of the central nervous system (CNS), continues to transform. In recent years, a number of novel and increasingly effective disease-modulatory therapies (DMTs) have been approved, including oral fumarates and selective sphingosine 1-phosphate modulators, as well as cell-depleting therapies such as cladribine, anti-CD20 and anti-CD52 monoclonals. Amongst DMTs in clinical development, inhibitors of Bruton's tyrosine kinase represent an entirely new emerging drug class in MS, with three different drugs entering phase III trials. However, important remaining fields of improvement comprise tracking of long-term benefit-risk with existing DMTs and exploration of novel treatment targets relating to brain inherent disease processes underlying the progressive neurodegenerative aspect of MS, which accumulating evidence suggests start already early in the disease process. The aim here is to review current therapeutic options in relation to an improved understanding of the immunopathogenesis of MS, also highlighting examples where controlled trials have not generated the desired results. An additional aim is to review emerging therapies undergoing clinical development, including agents that interfere with disease processes believed to be important for neurodegeneration or aiming to enhance reparative responses. Notably, early trials now have shown initial evidence of enhanced remyelination both with small molecule compounds and biologicals. Finally, accumulating evidence from clinical trials and post-marketing real-world patient populations, which underscore the importance of early high effective therapy whilst maintaining acceptable tolerability, is discussed.

Natalizumab, rituximab and fingolimod as escalation therapy in multiple sclerosis

BACKGROUND AND PURPOSE

Breakthrough disease on first-line injectables in relapsing-remitting multiple sclerosis (RRMS) is a common clinical situation where comparative studies between different escalation therapies are lacking. The aim of this study was to compare the efficacy, safety and medication persistence of natalizumab (NTZ), rituximab (RTX) and fingolimod (FGL) as escalation therapy in RRMS.

METHODS

Patients switching from interferon or glatiramer acetate to NTZ, RTX or FGL due to breakthrough disease were identified through the Swedish multiple sclerosis (MS) registry at four large MS centers in this retrospective observational study. Data were collected from the MS registry and medical charts. Hazard ratios (HRs) for relapses, adverse events and drug discontinuation with 95% confidence interval (CI) were calculated using multivariable confounder-adjusted Cox proportional hazard models.

RESULTS

A total of 241 patients were included. The annualized relapse rates were 0.02 for NTZ, 0.03 for RTX and 0.07 for FGL. Compared with NTZ, the adjusted HR for relapse was 1.0 (95% CI, 0.2-5.6) for RTX and 3.4 (95% CI, 1.3-9.2) for FGL. The annualized drug discontinuation rates were 0.15, 0.01 and 0.15 for NTZ, RTX and FGL, respectively. The adjusted HR for drug discontinuation was 0.05 (95% CI, 0.01-0.38) for RTX and 1.0 (95% CI, 0.6-1.7) for FGL vs. NTZ.

CONCLUSIONS

In patients with RRMS on interferon/glatiramer acetate with breakthrough disease, switching to NTZ or RTX was associated with less disease activity compared with FGL. RTX displayed superior medication persistence compared with both NTZ and FGL.

Increased number of monocytes and plasma levels of MCP-1 and YKL-40 in first-episode psychosis

OBJECTIVE

Accumulating evidence implicates immune activation in the development of schizophrenia. Here, monocyte numbers, monocyte chemoattractant protein-1 (MCP-1) and chitinase-3-like protein 1 (YKL-40) were investigated in plasma and cerebrospinal fluid (CSF) in first-episode psychosis (FEP) patients.

METHOD

CSF and blood were sampled from 42 first-episode psychosis (FEP) patients and 22 healthy controls. The levels of YKL-40 and MCP-1 were measured using electrochemiluminescence assay, and blood monocytes were counted using an XN-9000-hematology analyzer.

RESULTS

We found higher plasma levels of MCP-1 and YKL-40 in FEP patients compared with healthy controls, a condition that was unrelated to antipsychotic and/or anxiolytic medication. This was combined with an increased number of blood monocytes and a borderline significant increase in YKL-40 levels in the CSF of tobacco-free FEP patients. Plasma or CSF chemokines or blood monocytes did not correlate with the severity of symptoms or the level of functioning.

CONCLUSION

These data demonstrate activation of monocytes in FEP and strengthens the idea of an immune dysfunction of psychotic disorders. Further studies are required to perceive a role of YKL-40 and MCP-1 in the initiation and progression of schizophrenia.

THUR 172 Phase iv study of cladribine tablets and quality of life: clarify-ms

Authors Disclaimer: http://medpub-poster.merckgroup.com/ABN2018DISC_CLARIFY.pdf

Background

Relapsing multiple sclerosis (RMS) negatively affects health-related quality of life (HRQoL).

Objective

An open-label, single-arm, exploratory Phase IV study in centres in Europe and Australia will assess HRQoL in RMS patients receiving CT 3.5 mg/kg (CT3.5).

Methods

Eligible patients will receive CT 3.5 (cumulative) over 2 years. HRQoL (Multiple Sclerosis Quality of Life-54 [MSQoL-54]) and other patient-reported outcomes (Fatigue Severity Scale; Hospital Anxiety and Depression Scale; Treatment Satisfaction Questionnaire for Medication v1.4) will be assessed at baseline, and at 6, 12, 24 months.

Other outcomes include AEs, MRI measures (T1 Gd+ lesions, T2 lesions, brain atrophy), number of relapses, and disability/functioning measures (EDSS; 9-Hole Peg Test; Timed 25-Foot Walk and Brief International Cognitive Assessment for Multiple Sclerosis). The sample size estimation is based on the power to detect a mean difference of 5 points in MSQoL-54 composite score at 24 months vs baseline.

Results

The study aims to recruit 356 adults with RMS by 2019. Final data are anticipated in 2022.

Conclusions

This study will explore the effects of CT on HRQoL outcomes, and describe the effects of CT on treatment satisfaction and disability/functioning.

Disclosure statement

The trial is sponsored by Merck KGaA, Darmstadt, Germany.

Population-based incidence and clinical characteristics of idiopathic intracranial hypertension

OBJECTIVE

To validate the diagnosis of idiopathic intracranial hypertension (IIH) from the Swedish National Patient Register (NPR) and investigate the incidence of IIH, as well as co-morbidities and medication use in a large Swedish population-based sample.

METHODS

We searched the NPR to find all patients ≥18 years old with the ICD-10 diagnosis code (G93.2) for IIH in Stockholm County from Jan 1, 2006, to Dec 31, 2013. All medical records were reviewed to validate the diagnosis and to collect additional information.

RESULTS

We included 207 patients with an IIH diagnosis, of which 135 (65%) were correctly diagnosed when validated by charts review. Eighty-three patients had disease onset during the study period. This gave a yearly incidence of 0.65/100 000. Female-to-male ratio was 6.1:1. Females, mean age 31.0 (CI 28.8-33.1), were younger at time of diagnosis compared to males, mean age 42.9 (CI 36.4-49.5), P<.001. The most common co-morbidities were obesity (92%), hormonal conditions (21%) and recent infections preceding the diagnosis (21%). Prior treatment with tetracycline derivatives were seen in 9%.

CONCLUSION

The incidence of IIH in Stockholm is in the lower range of previously reported rates, possibly due to a lower prevalence of obesity. A substantial proportion of patients (35%) did not fulfill diagnostic criteria. Disease onset occurs at younger age in females. Co-morbidities were mainly associated with diseases affecting hormonal balance or causing inflammatory activation. These findings raise new hypothetical theories regarding mechanisms involved in IIH pathogenesis.

Tryptophan Metabolism Along the Kynurenine Pathway Downstream of Toll-like Receptor Stimulation in Peripheral Monocytes

Tryptophan degradation along the kynurenine pathway is of central importance for the immune function. Toll-like receptors (TLRs), representing the first line of immune defence against pathogens, are expressed in various cell types. The most abundant expression is found on monocytes, macrophages and dendritic cells. The aim of this study was to investigate whether stimulation with different TLR ligands induces the kynurenine pathway in human peripheral monocytes. Cell supernatants were analysed using a liquid chromatography/mass spectrometry to measure kynurenine, kynurenic acid (KYNA), quinolinic acid (QUIN) and tryptophan. Stimulation of TLR-2, TLR-3, TLR-4, TLR-7/8 and TLR-9 was found to induce the production of kynurenine, but only stimulation of TLR-3 increased levels of further downstream metabolites, such as KYNA and QUIN. Stimulation of TLR-1, TLR-5 and TLR-6 did not induce the kynurenine pathway. Taken together, this study provides novel evidence demonstrating that TLR activation induces a pattern of downstream tryptophan degradation along the kynurenine pathway in monocytes. The results of this study may implicate that TLRs can be used as new drug targets for the regulation of aberrant tryptophan metabolism along this pathway, a potential therapeutic strategy that may be of importance in several disorders.

Guidelines for the use of magnetic resonance imaging in diagnosing and monitoring the treatment of multiple sclerosis: recommendations of the Swedish Multiple Sclerosis Association and the Swedish Neuroradiological Society

Multiple sclerosis (MS) is associated with inflammatory lesions in the brain and spinal cord. The detection of such inflammatory lesions using magnetic resonance imaging (MRI) is important in the consideration of the diagnosis and differential diagnoses of MS, as well as in the monitoring of disease activity and predicting treatment efficacy. Although there is strong evidence supporting the use of MRI for both the diagnosis and monitoring of disease activity, there is a lack of evidence regarding which MRI protocols to use, the frequency of examinations, and in what clinical situations to consider MRI examination. A national workshop to discuss these issues was held in Stockholm, Sweden, in August 2015, which resulted in a Swedish consensus statement regarding the use of MRI in the care of individuals with MS. The aim of this consensus statement is to provide practical advice for the use of MRI in this setting. The recommendations are based on a review of relevant literature and the clinical experience of workshop attendees. It is our hope that these recommendations will benefit individuals with MS and guide healthcare professionals responsible for their care.

Fatigue and depression in multiple sclerosis: pharmacological and non-pharmacological interventions

Multiple sclerosis (MS) is a neuroinflammatory condition with a prominent progressive neurodegenerative facet that typically affects young- or middle-aged adults. Although physical disabilities have been in the foreground by being easier to assess, there is an increasing interest in mental disabilities and psychiatric co-morbidities, which have a disproportionally high impact on important outcome measures such as quality of life and occupational disability. In particular, cognitive impairment, depression and mental fatigue, which mutually interact with each other, seem to be of importance in this context. In recent decades, major efforts have been invested in developing more effective disease modulatory treatments. This has resulted in novel therapeutic options and awareness of the importance of early intervention. In comparison, good quality and adequately powered studies on symptomatic treatments of fatigue and psychiatric co-morbidities in MS are rare, and awareness of treatment options is much lower. We here review the existing evidence base for symptomatic treatment of fatigue and depression in MS patients. With regard to fatigue, off-label prescription of alertness improving drugs is common, in spite of all but absent evidence of efficacy. In contrast, a number of smaller studies suggest that physical exercise and fatigue management courses may have some clinical benefit. Very few studies have addressed the efficacy of antidepressants and non-pharmaceutical interventions specifically in MS patients. Therefore, treatment guidelines largely rely on data from non-MS populations. In the future, there is a strong motive to direct additional resources to the study of these important aspects of MS.

The autoimmune spectrum of myasthenia gravis: a Swedish population-based study

OBJECTIVES

To determine the prevalence of myasthenia gravis (MG) and the rate of concurrent autoimmune diseases in patients with MG.

DESIGN AND SETTING

Using the Swedish health and population registers, during the period 2005-2010, we conducted a nested case-control study of patients with MG (n = 2045) with five age- and sex-matched population-based controls per case. Register-based MG diagnosis was validated against the Stockholm MG Cohort. Similar nested case-control studies were conducted in patients with multiple sclerosis (MS), as a neuroinflammatory disease control, and siblings of patients with MG.

MAIN OUTCOME MEASURE

Odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated as a measure of the association between MG and other autoimmune diseases.

RESULTS

The prevalence of MG was 24.8/100,000, and patients with MG had an increased risk of another autoimmune disease compared to controls (22.0% vs. 8.9%; OR: 2.82, 95% CI: 2.49-3.20); this risk was stronger amongst younger persons and women. Polymyositis/dermatomyositis, systemic lupus erythematosus and Addison's disease, three conditions regulated by the HLA-B8-DR3 haplotype, were most strongly associated with MG, especially early-onset disease. HLA typing in the Stockholm MG Cohort showed that early-onset MG was indeed dominated by HLA-B8-DR3. The risk of another autoimmune disease was increased in both patients with MS and siblings of patients with MG, compared to their respective controls, but to a lesser extent than in patients with MG.

CONCLUSIONS

Our results suggest that MG shares risk factors with other autoimmune diseases, to a greater degree than MS, with a particular role of the HLA-B8-DR3 haplotype, especially amongst younger and female patients.

Comparative analysis of first-year fingolimod and natalizumab drug discontinuation among Swedish patients with multiple sclerosis

BACKGROUND

Natalizumab (NTZ) and fingolimod (FGL) are mainly used second line in relapsing-remitting multiple sclerosis (MS), although pivotal trials included mainly treatment-naïve patients.

OBJECTIVE

This study aims to provide real-world data on safety and discontinuation rates.

METHODS

Using IMSE, a drug monitoring registry for all newer MS drugs in Sweden, we analysed differences in baseline characteristics and 1-year drug survival for patients registered 2011-2013, initiating treatment with NTZ (n=640) or FGL (n=876). Among FGL initiators, n=383 (44%) had previously used NTZ (FGL(afterNTZ)).

RESULTS

Compared with NTZ, the FGL cohort was older and more often male (36/38 years, 24%/33% males). Baseline Expanded Disability Status Scale was similar across groups, but MS Severity Score was higher in NTZ patients, and Symbol Digit Modalities Test and MS Impact Scale (MSIS-29) was higher in FGL(afterNTZ) versus FGL(NTZ-naïve) patients. Proportion on drug after 1 year was high, NTZ=87%, FGL(NTZ-naïve)=83% and FGL(afterNTZ)=76%. Adverse events was the most frequent reason for discontinuing FGL (FGL(NTZ-naïve)=9%, FGL(afterNTZ)=12%), and was significantly higher than on NTZ (3%). In contrast, the proportion of patients stopping treatment due to lack of effect was more similar: NTZ=4%, FGL(NTZ-naïve)=3%, FGL(afterNTZ)=8%.

CONCLUSION

FGL and NTZ were both well tolerated, but FGL less so than NTZ, especially in patients switching to FGL from NTZ. Group differences were not explained by differences in recorded baseline characteristics.

Conversion from clinically isolated syndrome to multiple sclerosis: A large multicentre study

Background and objective:

We explored which clinical and biochemical variables predict conversion from clinically isolated syndrome (CIS) to clinically definite multiple sclerosis (CDMS) in a large international cohort.

Methods:

Thirty-three centres provided serum samples from 1047 CIS cases with at least two years’ follow-up. Age, sex, clinical presentation, T2-hyperintense lesions, cerebrospinal fluid (CSF) oligoclonal bands (OCBs), CSF IgG index, CSF cell count, serum 25-hydroxyvitamin D3 (25-OH-D), cotinine and IgG titres against Epstein-Barr nuclear antigen 1 (EBNA-1) and cytomegalovirus were tested for association with risk of CDMS.

Results:

At median follow-up of 4.31 years, 623 CIS cases converted to CDMS. Predictors of conversion in multivariable analyses were OCB (HR = 2.18, 95% CI = 1.71–2.77, p < 0.001), number of T2 lesions (two to nine lesions vs 0/1 lesions: HR = 1.97, 95% CI = 1.52–2.55, p < 0.001; >9 lesions vs 0/1 lesions: HR = 2.74, 95% CI = 2.04–3.68, p < 0.001) and age at CIS (HR per year inversely increase = 0.98, 95% CI = 0.98–0.99, p < 0.001). Lower 25-OH-D levels were associated with CDMS in univariable analysis, but this was attenuated in the multivariable model. OCB positivity was associated with higher EBNA-1 IgG titres.

Conclusions:

We validated MRI lesion load, OCB and age at CIS as the strongest independent predictors of conversion to CDMS in this multicentre setting. A role for vitamin D is suggested but requires further investigation.

High interleukin-6 and impulsivity: determining the role of endophenotypes in attempted suicide

The dysregulation of inflammation has been associated with depression and, more recently, with suicidal behaviors. The reports regarding the relationship between interleukin-6 (IL-6) and suicide attempts are inconsistent. Personality traits such as impulsivity and aggression are considered endophenotypes and important factors that underlie suicidal behaviors. The aim of the current study was to assess whether plasma and cerebrospinal fluid (CSF) levels of IL-6 are associated with personality traits among suicide attempters. We assessed the relationships among personality traits, IL-6 and violent suicide attempts. The plasma and CSF levels of IL-6 were measured in suicide attempters (plasma=58, CSF=39) using antibody-based immunoassay systems. Personality domains were assessed using the Karolinska Scale of Personality (KSP). IL-6 levels in plasma and CSF were used to predict personality domains via regression models. Plasma IL-6 was significantly and positively correlated with extraversion as well as the KSP subscales impulsivity and monotony avoidance. CSF IL-6 was positively correlated with monotony avoidance. Violent suicide attempts tended to be associated with high plasma IL-6 levels. Plasma and CSF levels of IL-6 were not significantly associated with each other. These results indicate that impulsivity and the choice of a violent suicide attempt method might be related to higher levels of IL-6 in individuals who attempt suicide. The neuroinflammation hypothesis of suicidal behavior on the basis of elevated IL-6 levels might be partly explained by the positive association between IL-6 and impulsivity, which is a key element of the suicidal phenotype.

A changing treatment landscape for multiple sclerosis: challenges and opportunities

Multiple sclerosis (MS) is primarily an autoimmune disease of the central nervous system, but also encompasses prominent neurodegenerative aspects. A significant proportion of MS patients will develop neurological disability over time and up until recently treatment options have been limited. However, MS treatment is now at a stage of rapid progress, with several new drugs that have reached the market or will be launched in the near future. This provides new opportunities for individualized treatment, but also creates new challenges regarding monitoring of disease activity, long-term safety issues and efficacy, not least in patients with progressive disease.

The DQB1(*)03:02 HLA haplotype is associated with increased risk of chronic pain after inguinal hernia surgery and lumbar disc herniation

Neuropathic pain conditions are common after nerve injuries and are suggested to be regulated in part by genetic factors. We have previously demonstrated a strong genetic influence of the rat major histocompatibility complex on development of neuropathic pain behavior after peripheral nerve injury. In order to study if the corresponding human leukocyte antigen complex (HLA) also influences susceptibility to pain, we performed an association study in patients that had undergone surgery for inguinal hernia (n = 189). One group had developed a chronic pain state following the surgical procedure, while the control group had undergone the same type of operation, without any persistent pain. HLA DRB1genotyping revealed a significantly increased proportion of patients in the pain group carrying DRB1(*)04 compared to patients in the pain-free group. Additional typing of the DQB1 gene further strengthened the association; carriers of the DQB1(*)03:02 allele together with DRB1(*)04 displayed an increased risk of postsurgery pain with an odds risk of 3.16 (1.61-6.22) compared to noncarriers. This finding was subsequently replicated in the clinical material of patients with lumbar disc herniation (n = 258), where carriers of the DQB1(*)03:02 allele displayed a slower recovery and increased pain. In conclusion, we here for the first time demonstrate that there is an HLA-dependent risk of developing pain after surgery or lumbar disc herniation; mediated by the DRB1(*)04-DQB1(*)03:02 haplotype. Further experimental and clinical studies are needed to fine-map the HLA effect and to address underlying mechanisms.

Multiple sclerosis risk genotypes correlate with an elevated cerebrospinal fluid level of the suggested prognostic marker CXCL13

Background:

The mechanisms of multiple sclerosis (MS) pathogenesis are still largely unknown. The heterogeneity of disease manifestations make the prediction of prognosis and choice of appropriate treatment protocols challenging. Recently, increased cerebrospinal fluid (CSF) levels of the B-cell chemokine CXCL13 was proposed as a possible marker for a more severe disease course and conversion from clinically isolated syndrome (CIS) to relapsing–remitting MS (RRMS).

Objective:

To investigate whether there are genetic susceptibility variants in MS that correlate with the levels of CXCL13 present in the CSF of MS patients.

Methods:

We genotyped the human leukocyte antigens HLA-DRB1 and HLA-A, plus a panel of single nucleotide polymorphisms (SNPs) that have been associated with susceptibility to MS and then correlated the genotypes with the levels of CXCL13, as measured with ELISA in the CSF of a total of 663 patients with MS, CIS, other neurological diseases (OND) or OND with an inflammatory component (iOND).

Results:

Presence of the HLA-DRB1*15 and the MS risk genotypes for SNPs in the RGS1, IRF5 and OLIG3/TNFAIP3 gene regions correlated significantly with increased levels of CXCL13.

Conclusion:

Our results pointed towards a genetic predisposition for increased CXCL13 levels, which in MS patients correlates with the severity of the disease course. These findings encourage further investigation and replication, in an independent patient cohort.

Time to secondary progression in patients with multiple sclerosis who were treated with first generation immunomodulating drugs

BACKGROUND

It is currently unknown whether early immunomodulatory treatment in relapsing-remitting MS (RRMS) can delay the transition to secondary progression (SP).

OBJECTIVE

To compare the time interval from onset to SP in patients with RRMS between a contemporary cohort, treated with first generation disease modifying drugs (DMDs), and a historical control cohort.

METHODS

We included a cohort of contemporary RRMS patients treated with DMDs, obtained from the Swedish National MS Registry (disease onset between 1995-2004, n = 730) and a historical population-based incidence cohort (onset 1950-64, n = 186). We retrospectively analyzed the difference in time to SP, termed the "period effect" within a 12-year survival analysis, using Kaplan-Meier and Cox regression analysis.

RESULTS

We found that the "period" affected the entire severity spectrum. After adjusting for onset features, which were weaker in the contemporary material, as well as the therapy initiation time, the DMD-treated patients still exhibited a longer time to SP than the controls (hazard ratios: men, 0.32; women, 0.53).

CONCLUSION

Our results showed there was a longer time to SP in the contemporary subjects given DMD. Our analyses suggested that this effect was not solely driven by the inclusion of benign cases, and it was at least partly due to the long-term immunomodulating therapy given.

Genetic and sex influence on neuropathic pain-like behaviour after spinal cord injury in the rat

BACKGROUND

Chronic pain of neuropathic nature after spinal cord injury (SCI) is common and its underlying mechanisms are poorly understood. Genes, as well as sex, have been implicated, but not thoroughly investigated in experimental genetic models for complex traits. We have previously found that inbred Dark-Agouti (DA) rats develop more severe SCI pain-like behaviour than a major histocompatibility complex-congenic Piebald Virol Glaxo (PVG)-RT1(av1) strain in a model of photochemically induced SCI.

METHODS

In this study, a genome-wide linkage study in an F2 cross between the susceptible DA and resistant PVG-RT1(av1) strains was performed in order to explore the influence of genes and sex for SCI pain.

RESULTS

A consistent finding was that female rats in parental, F1 and F2 generations displayed increased pain sensitivity at testing before injury and also developed mechanical hypersensitivity more rapidly and to a greater extent than male rats. In addition, we could identify three quantitative trait loci (QTLs) associated with pain-like behaviour: a sex-specific QTL on chromosome 2, one on chromosome 15 and on chromosome 6. Animals carrying DA alleles at each of these loci were more susceptible to development of mechanical hypersensitivity compared with rats with PVG alleles.

CONCLUSION

This is the first whole genome QTL mapping of neuropathic pain-like behaviour in a model of SCI. The results provide strong support for a significant genetic and sex component in development of pain after SCI and provide the basis for further genetic dissection and positional cloning of the underlying genes.

High levels of 15-oxygenated steroids in circulation of patients with multiple sclerosis: fact or fiction?

15-Oxygenated cholesterol species such as 5α-cholest-8(14)ene-3β,15α-diol (15HC) and 3β-hydroxy-5α-cholest-8(14)-en-15-one (15KC) are commercially available synthetic products unlikely to occur in biological systems. Surprisingly, Farez et al. recently reported that these two steroids occur in human circulation at levels considerably higher than those of any other endogenous oxysterol [Farez, M. et al. 2009. Toll-like receptor 2 and poly(ADP-ribose) polymerase 1 promote central nervous system neuroinflammation in progressive EAE. Nat. Immunol. 10: 958-964]. The levels were reported to be increased in patients with multiple sclerosis in a progressive phase and the authors suggested that this could be utilized diagnostically. Based on extensive in vitro experiments exposing cells to the same high levels of 15HC as found in vivo (1000 ng/ml) the authors concluded that 15HC may be an important pathogenetic factor in multiple sclerosis. Using combined gas chromatography-mass spectrometry we fail to detect significant plasma levels of 15HC either in healthy controls or in patients with multiple sclerosis (levels < 2 ng/ml). If 15KC is present in these plasma samples, the concentration of it must be <10 ng/ml. Our failure to detect significant levels of the above steroids could not be due to loss during hydrolysis and work-up because recovery of the added two oxysterols was close to 100%. Autoxidation of lipoprotein-bound cholesterol resulted in extensive conversion of cholesterol into 7-oxygenated but not 15-oxygenated sterols. We conclude that if present there are trace amounts only of the above 15-oxygenated steroids in human circulation and that the role of such oxysterols as pathogenetic factors and biomarkers must be reconsidered.

The effects of natalizumab on inflammatory mediators in multiple sclerosis: prospects for treatment-sensitive biomarkers

BACKGROUND

Natalizumab affects systemic cytokine expressions and clinical course in relapsing-remitting multiple sclerosis (RRMS). We analyzed levels of inflammatory cytokines in cerebrospinal fluid (CSF) cells and peripheral blood mononuclear cells (PBMCs), levels of matrix metalloproteinase (MMP)-9 and osteopontin (OPN) in CSF, and clinical outcome measures in 22 natalizumab-treated RRMS patients.

METHODS

mRNA levels of cytokines in cells were detected with real-time RT-PCR. Protein levels of OPN and MMP-9 were measured by ELISA.

RESULTS

Natalizumab reduced CSF cell counts (P < 0.0001). Tumor necrosis factor (TNF) and interferon-gamma (IFN-gamma) mRNAs were significantly increased in PBMCs. In contrast, expressions of IFN-gamma and interleukin (IL)-23 were decreased but IL-10 increased in the CSF cells. OPN and MMP-9 were reduced in the CSF. Patients being in remission at baseline showed the same deviations of mediators as those in relapse after natalizumab treatment. The open label clinical outcome measures were either stable or improved during therapy.

CONCLUSIONS

Natalizumab attenuates pro-inflammatory mediators intrathecally and the reduced pro-inflammatory milieu may allow increased production of the anti-inflammatory mediator IL-10. The increased systemic cytokines may impede the improvement of certain clinical measures like fatigue. The affected mediators seem to be sensitive to an immune-modifying treatment which could be used as biomarkers for this therapy.

Decreased Expression of VEGF-A in Rat Experimental Autoimmune Encephalomyelitis and in Cerebrospinal Fluid Mononuclear Cells from Patients with Multiple Sclerosis

Vascular endothelial growth factor A (VEGF-A) stimulates angiogenesis, but is also pro-inflammatory and plays an important role in the development of neurological disease, where it can have both attenuating and exacerbating effects. VEGF-B, a related molecule, is highly expressed in the central nervous system and seems to be important in neurological injury. A few studies have indicated that VEGF-A may play a role in the pathogenesis of multiple sclerosis (MS), but the role of VEGF-B has not been studied. We have studied the expression of VEGF-A, -B and their receptors by mRNA in situ hybridization, immunohistochemistry and real-time PCR in spinal cord from LEW rats with experimental autoimmune encephalomyelitis (EAE) and in cerebrospinal fluid (CSF) and blood samples from MS patients. Whereas VEGF-A is downregulated in glia in EAE, the infiltrating inflammatory cells are positive for VEGF-A. Expression of VEGF-B and the VEGF receptors is unaltered. In addition, the levels of VEGF-A mRNA in mononuclear cells [corrected] in CSF are lower in MS patients compared with controls. These results demonstrate a complex regulation of VEGF-A during neuroinflammation and suggest that VEGF-B is not involved in the pathogenesis of MS.

Increased brain-derived neurotrophic factor expression in white blood cells of relapsing-remitting multiple sclerosis patients

Central nervous system (CNS)-autoreactive immune responses can exert neuroprotective effects, possibly mediated via the release of neurotrophic factors from infiltrating leucocytes. Herein, we analysed neurotrophin and cytokine mRNA levels using TaqMan polymerase chain reaction in unstimulated peripheral blood mononuclear cells (PBMCs) from multiple sclerosis (MS) patients in remission and controls. We demonstrate that mRNA for brain-derived neurotrophic factor (BDNF), but not neurotrophin-3 or nerve growth factor (NGF), is readily detectable in PBMC and that levels in MS are increased by approximately 60% compared with patients with other neurological diseases or healthy subjects. These results provide additional evidence that a potentially neuroprotective facet of autoimmune inflammation is present in MS.

Properties of motoneurons underlying their regenerative capacity after axon lesions in the ventral funiculus or at the surface of the spinal cord

Spinal motoneurons represent neurons with axons located in both the central (CNS) and peripheral (PNS) nervous systems. Following a lesion to their axons in the PNS, motoneurons are able to regenerate. The regenerative capacity of these neurons is seen also after lesion in the ventral funiculus of the spinal cord, i.e. within the CNS compartment. Thus, after an axotomy within the ventral funiculus, motoneurons respond with a changing polarity towards production of axons, sometimes even from the dendritic tree. This capacity can be used in cases of ventral root avulsion (VRA) lesions, if a conduit for outgrowing axons is presented in the form of replanted ventral roots. In human cases, this procedure may accomplish return of function in denervated muscles. The strong regenerative capacity of motoneurons provides the basis for studies of the response in motoneurons with regard to their contents of substances related to survival and regeneration. Such studies have shown that, of the large number of receptors for neurotrophic substances and extracellular matrix molecules, mRNAs for receptors or receptor components for neurotrophin-3 (NT-3), ciliary neurotrophic factor (CNTF) and leukemia inhibitory factor (LIF) are strongly downregulated after VRA, while receptors for glial cell line-derived neurotrophic factor (GDNF) and laminins are profoundly upregulated. These results should be considered in the design of combined pharmacological and surgical approaches to lesions of motor axons at or close to the CNS-PNS interface.

Differential expression of neurotrophic factors and inflammatory cytokines by myelin basic protein-specific and other recruited T cells infiltrating the central nervous system during experimental autoimmune encephalomyelitis

Recent evidence suggests that autoimmune reactions in the central nervous system (CNS) not only have detrimental consequences but can also be neuroprotective, and that this effect is mediated by the expression of neuronal growth factors by infiltrating leucocytes. Here we dissect these two phenomena in guinea pig myelin basic protein peptide (gpMBP 63-88)-induced experimental autoimmune encephalomyelitis (EAE) in the Lewis rat. Real-time TaqMan polymerase chain reaction (PCR) was used to measure mRNA for the nerve growth factors, brain-derived neurotrophic factor (BDNF) and neurotrophin (NT)-3. As reference, the well-known proinflammatory mediator molecules interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha were quantified. In whole lumbar cord tissue, both the nerve growth factors and the proinflammatory cytokines, IFN-gamma and TNF-alpha, displayed similar expression patterns, peaking at the height of the disease. Among the infiltrating inflammatory cells isolated and sorted from the CNS, alphabeta+/T-cell receptor (TCR)BV8S2+, but not alphabeta+/TCRBV8S2-, recognized the encephalitogenic MBP peptide. Interestingly, these two populations displayed contrasting expression patterns of nerve growth factors and proinflammatory cytokines with higher inflammatory cytokine mRNA levels in alphabeta+/TCRBV8S2+ cells at all time intervals, whereas the levels of BDNF and NT3 were higher in alphabeta+/TCRBV8S2- cells. We conclude that a potentially important neuroprotective facet of CNS inflammation dominantly prevails within other non-MBP peptide-specific lymphoid cells and that there are independent regulatory mechanisms for neurotrophin and inflammatory cytokine expression during EAE.

Neuroinflammation in the rat--CNS cells and their role in the regulation of immune reactions

Recent discoveries suggest that the resident cells of the central nervous system (CNS) the nerve cells and glia, play a more immunologically active role than was previously assumed. Neuroglial communication is of central interest in virtually all types of pathological conditions that affect the brain and several features of the activation that results from nerve cell damage resemble the type of innate immune reactions that occur in other parts of the body In particular, the characteristics of the activation of these CNS cells will affect both the interaction with cells of the immune system as well as processes related to neurodegeneration and regeneration. We here review data regarding 3 different aspects of local inflammatory activation in the rat nervous system: (i) the genetic heterogeneity of glial activation across inbred strains after nerve injury, (ii) expression of MHC class I genes in the CNS and (iii) neuroprotective effects of CNS antigen autoreactive immune reactions. Apart from neuroimmune diseases such as experimental autoimmune encephalomyelitis/multiple sclerosis, these features are also of relevance for a wider range of neurological diseases which present pathological signs of inflammation, such as Alzheimer's dementia, cerebrovascular diseases and CNS trauma.

Differential expression of multiple alternative spliceforms of the Men1 tumor suppressor gene in mouse

The multiple endocrine neoplasia type 1 gene (MEN1) is a tumor suppressor gene associated with the development of tumors in the parathyroids, the pituitary, and the pancreas and has also been linked to impaired germ cell production. The murine ortholog, Men1, is highly homologous to the human counterpart both at DNA and protein levels. The present study was undertaken to further approach the function of Men1 and its encoded protein menin. By 5' RACE and RT-PCR four alternative splice variants were identified, indicating a 5' heterogeneity of Men1 similar to the human counterpart. By mRNA in situ hybridization of embryonal and adult mouse tissues, all four splice variants were shown to be expressed, albeit at varying timepoints and levels in the different tissues. However, a putative isoform postulated from the DNA sequence, which would elongate the reading frame by 15 bases at the exon 2/intron 2 junction, was not found to occur in mouse. The strongest expression was detected in testis, both at the mRNA and protein level and was therefore further characterized by protein analysis of cells isolated from different stages of the spermatogenesis. Western blotting revealed a single protein of approximately 70 kDa detected in total testis, isolated pachytene spermatocytes and in haploid spermatids. Notably, no menin expression was detectable in the extracts from epididymis where the maturation of sperms is almost completed, suggesting that menin plays a crucial role during spermatogenesis.

Menin interacts directly with the homeobox-containing protein Pem

The tumour suppressor gene causing multiple endocrine neoplasia type 1 (MEN1) encodes a 610 amino acid protein, menin. In order to identify menin-interacting proteins we used a yeast two-hybrid assay to screen a 12.5-dpc mouse embryo library with partial menin encompassing amino acids 278 to 476. This identified a homeobox containing protein encoded by a placenta and embryonic expression gene, referred to as Pem. GST-pull-down and coimmunoprecipitation experiments confirmed the interaction. Both proteins colocalised predominantly in the nucleus but were occasionally also found in the cytoplasm. Furthermore, in situ hybridisation studies revealed similarities in their expression patterns in mouse embryos and adult tissues. In adult mice both Men1 and Pem yielded strong signals in testis, Sertoli cells and particularly in seminiferous tubules. Thus, our study has identified that menin interacts with Pem, and the high expression of these proteins in the testis suggests a role in spermatogenesis.

Genetic regulation of nerve avulsion-induced spinal cord inflammation

In the animal model for multiple sclerosis (MS), experimental autoimmune encephalitis (EAE), genetic loci correlating with incidence or severity of disease are located both within and outside of the major histocompatibility complex (MHC). Whereas polymorphisms within MHC class I and II molecules are likely to be a major determinant of MHC gene influence in rat EAE, it is still unclear how non-MHC gene regions influence disease. Genetic control of inflammation can hypothetically be either general or specific for a particular target tissue. For the latter, gene regulation of pathomechanisms in the CNS could affect reactivity of microglia or astrocytes, local cytokine/chemokine production, or even neuronal vulnerability. We have obtained strong support for this notion by observations of rat strain-dependent variation in the inflammatory response after ventral root avulsion, a model in which mainly non-antigen-specific elements of the immune system promote inflammation. A comparison of strains with similar MHC haplotypes on different backgrounds and strains with different MHC haplotypes on the same background, respectively, demonstrates that the inflammatory phenotype is regulated mainly by non-MHC genes. Interestingly, different features of the inflammatory response, such as induction of MHC class II expression, glial activation, cytokine expression, and neuronal vulnerability, varied between rat strains and were largely independent of each other. The genetic control of several basic features of inflammation in the CNS is of great relevance not only for MS/EAE, but also for several other neurological conditions with inflammatory components such as cerebrovascular and neurogenerative dieases and trauma.

Neurodegeneration and glial activation patterns after mechanical nerve injury are differentially regulated by non-MHC genes in congenic inbred rat strains

Ventral root avulsion in the rat leads to a retrograde response, with activation of glia and up-regulation of immunologic cell surface molecules such as major histocompatibility complex (MHC) antigens, and the subsequent degeneration of a large proportion of the lesioned motoneurons. Herein, we examined several inbred congenic rat strains previously known to react differently to experimentally induced autoimmune diseases and demonstrate a substantial genetic diversity in the regulation of glial activation and neuron death in this injury model. The panel of examined inbred rat strains included DA(RT1AV1), PVG.1AV1, LEW.1AV1, LEW.1N, BN(RT1N) and E3(RT1U), and the following parameters were determined: (1) MHC class II expression on glia; (2) expression of glial fibrillary acidic protein, C3 complement, and microglial response factor-1 mRNAs in glia; (3) levels of the tumor necrosis factor-alpha and interleukin-1beta cytokine mRNAs; (4) degree of motoneuron loss. The findings of considerable strain-dependent differences in all parameters studied demonstrate important polymorphisms in the genetic regulation of these events. Furthermore, some of the studied features segregated from each other, suggesting independent regulatory mechanisms. Genes outside of the MHC complex are mainly implicated as being of importance for the phenotypic differences, as significant differences were recorded between the MHC congenic strains differing in the non-MHC genes but not vice versa. These results contribute new important insights into the genetic regulation of glial reactivity and neuron death after mechanical nerve injuries. In addition, the finding of conspicuous strain-dependent differences makes it necessary to consider the genetic background when designing and interpreting animal experiments involving noxious insults to the central nervous system resulting in glial activation and nerve cell loss.

Regulation of laminin-associated integrin subunit mRNAs in rat spinal motoneurons during postnatal development and after axonal injury

Two important prerequisites for successful axon regeneration are that appropriate extracellular molecules are available for outgrowing axons and that receptors for such molecules are found in the regenerating neuron. Laminins and their receptors in the integrin family are examples of such molecules, and laminin-associated integrin subunits alpha 3, alpha 6, alpha 7, and beta 1 mRNAs have all been detected in adult rat motoneurons. We have here, by use of in situ hybridization histochemistry, examined the normal postnatal development of the expression in motoneurons of these mRNAs and integrin beta 4 mRNA, all of which have been associated with laminin-2. We studied the regulation of these mRNAs, 1-42 days after two types of axotomy in the adult rat (sciatic nerve transection, SNT; ventral root avulsion, VRA) and 1-10 days after SNT in the neonatal animal. During postnatal development, there was a distinct shift in the integrin composition from a stronger expression of the alpha 6 subunit to a very clear dominance of alpha 7 in the adult. All types of axotomy in the adult rat induced initial (1-7 days) large up-regulations of alpha 6, alpha 7 and beta1 subunit mRNAs (250-500%). Only minor changes for alpha 3 mRNA were seen, and beta 4 mRNA could not be detected at all in motoneurons. After adult SNT, the alpha 7 and beta 1 subunits were up-regulated throughout the studied period, and the alpha 6 subunit mRNA was eventually normalized. After VRA, however, the alpha 7 and beta1 levels peaked earlier than after SNT and were normalized at 42 days, whereas alpha 6 mRNA was up-regulated longer than after SNT. Neonatal SNT had much smaller effects on the expression of the studied subunits. The results suggest that an important part of the response to axotomy of motoneurons is to up-regulate receptors for laminin. The developmental shift in integrin subunit composition and the various responses seen in the lesion models indicate that different isoforms of laminin play a role in the regenerative response.

Differential regulation of trophic factor receptor mRNAs in spinal motoneurons after sciatic nerve transection and ventral root avulsion in the rat

After sciatic nerve lesion in the adult rat, motoneurons survive and regenerate, whereas the same lesion in the neonatal animal or an avulsion of ventral roots from the spinal cord in adults induces extensive cell death among lesioned motoneurons with limited or no axon regeneration. A number of substances with neurotrophic effects have been shown to increase survival of motoneurons in vivo and in vitro. Here we have used semiquantitative in situ hybridization histochemistry to detect the regulation in motoneurons of mRNAs for receptors to ciliary neurotrophic factor (CNTF), leukemia inhibitory factor (LIF), glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3) 1-42 days after the described three types of axon injury. After all types of injury, the mRNAs for GDNF receptors (GFRalpha-1 and c-RET) and the LIF receptor LIFR were distinctly (up to 300%) up-regulated in motoneurons. The CNTF receptor CNTFRalpha mRNA displayed only small changes, whereas the mRNA for membrane glycoprotein 130 (gp130), which is a critical receptor component for LIF and CNTF transduction, was profoundly down-regulated in motoneurons after ventral root avulsion. The BDNF full-length receptor trkB mRNA was up-regulated acutely after adult sciatic nerve lesion, whereas after ventral root avulsion trkB was down-regulated. The NT-3 receptor trkC mRNA was strongly down-regulated after ventral root avulsion. The results demonstrate that removal of peripheral nerve tissue from proximally lesioned motor axons induces profound down-regulations of mRNAs for critical components of receptors for CNTF, LIF, and NT-3 in affected motoneurons, but GDNF receptor mRNAs are up-regulated in the same situation. These results should be considered in relation to the extensive cell death among motoneurons after ventral root avulsion and should also be important for the design of therapeutical approaches in cases of motoneuron death.

Induction of VEGF and VEGF receptors in the spinal cord after mechanical spinal injury and prostaglandin administration

Vascular endothelial growth factor (VEGF) is an angiogenetic factor that promotes endothelial cell proliferation during development and after injury to various types of tissue, including the central nervous system (CNS). Using immunohistochemical and in situ hybridization methods we have here demonstrated that VEGF and its receptors Flk-1, Flt-1 and Neuropilin-1 mRNAs and proteins are induced after incisions in the rat spinal cord. The inducible enzyme for prostaglandin synthesis cyclooxygenase-2 (COX-2) is known to be upregulated after spinal injury, cerebral ischemia and to stimulate angiogenesis. To test the hypothesis that prostaglandins may be involved in the VEGF response after lesion we investigated whether intraspinal microinjections of prostaglandin F2alpha (PGF2alpha) alters VEGF expression in the spinal cord. Such treatment was followed by a strong upregulation of VEGF mRNA and protein in the injection area. Finally, by use of an in vitro model with cell cultures of meningeal fibroblast and astrocyte origin, resembling the lesion area cellular content after spinal cord injury but devoid of inflammatory cells, we showed that VEGF is expressed in this in vitro model cell system after treatment with PGF2alpha and prostaglandin E2 (PGE2). These data suggest that cells within a lesion area in the spinal cord are capable of expressing VEGF and its receptors in response to mechanical injury and that prostaglandins may induce VEGF expression in such cells, even in the absence of inflammatory cells.

Genetics of rat neuroinflammation

The definition of genes regulating the pathogenetic pathways of autoimmune neuroinflammation, may provide targets for new therapeutic strategies. This is not easily accomplished in human disease. Such genetic dissection can more readily be done by the use of inbred rodent strains. With these, genetic heterogeneity is avoided and variation in the environmental influences is minimized. Close mimicking of the human disease characteristics is desirable in such endeavors. Chronic relapsing experimental autoimmune encephalomyelitis (EAE) with MS-like histopathology is achieved after immunization of certain rat strains with myelin oligodendrocyte glycoprotein (MOG) or spinal cord homogenate. The major histocompatibility complex (MHC) regulate the ease by which the environmental trigger in the form of immunisation induces disease. Use of intra-MHC recombinant strains demonstrated major influences from the MHC class II genome region, but additional influences from both the MHC class I and III regions. These findings now provide a basis for studies of the mechanisms for MHC-controlled autoimmune pathogenicity leading to MS-like disease. Gene mapping of F2 crosses between susceptible and resistant rat strains demonstrated nine genome regions outside the MHC which regulate different phenotypes of rat EAE. Many of these co-localize with genome regions regulating other organ-specific disease such experimental arthritis, suggesting a sharing of disease pathways. Further finemapping can lead to the exact identification of disease regulating genes. Interestingly, we have also demonstrated a non-MHC gene control of the inflammatory response, in the form of glial cell activation, and neuronal degeneration, subsequent to anterior nerve root avulsion in rats. The genetic dissection of these influences may unravel pathways controlling CNS vulnerability.

Neuroprotection by encephalomyelitis: rescue of mechanically injured neurons and neurotrophin production by CNS-infiltrating T and natural killer cells

In experimental autoimmune encephalomyelitis (EAE), CD4(+) self-reactive T cells target myelin components of the CNS. However, the consequences of an autoaggressive T cell response against myelin for neurons are currently unknown. We herein demonstrate that EAE induced by active immunization with an encephalitogenic myelin basic protein peptide dramatically reduces the loss of spinal motoneurons after ventral root avulsion in rats. Both brain-derived neurotophic factor (BDNF)- and neurotrophin-3 (NT-3)-like immunoreactivities were detected in mainly T and natural killer (NK) cells in the spinal cord. In addition, very high levels of BDNF, NT-3, and glial cell line-derived neurotrophic factor mRNAs were present in T and NK cell populations infiltrating the CNS. Interestingly, bystander recruited NK and T cells displayed similar or higher neurotrophic factor levels compared with the EAE disease-driving encephalitogenic T cell population. High levels of tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) mRNAs were also detected, and both these cytokines can be harmful to several types of CNS cells, including neurons. However, treatment of embryonic motoneuron cultures with TNF-alpha or IFN-gamma only had a deleterious effect in cultures deprived of neurotrophic factors. These results suggest that the potentially neurodamaging consequences of severe CNS inflammation are curbed by the production of several potent neurotrophic factors in leukocytes.

Reduction of both pro- and anti-inflammatory cytokines after 6 months of interferon beta-1a treatment of multiple sclerosis

Treatment of multiple sclerosis (MS) with interferon beta (IFNbeta) reduces relapse rate, magnetic resonance imaging (MRI) activity and progression of disability. It has been suggested that this beneficial effect is paralleled by an inhibition of proinflammatory cytokines such as interferon gamma (IFNgamma) and tumor necrosis factor alpha (TNFalpha) and an induction of anti-inflammatory cytokines such as interleukin-4 (IL-4) and interleukin-10 (IL-10). In this study, we record a reduced number of spontaneously IFNgamma mRNA-expressing cerebrospinal fluid mononuclear cells (CSF-MC) and IFNgamma, TNFalpha and IL-10 mRNA-expressing peripheral blood mononuclear cells (PBMC) after 6 months of IFNbeta-1a treatment, paralleled by a decreased purified protein derivate (PPD)-stimulated and unstimulated IFNgamma secretion by PBMC. These effects were not apparent after 2 weeks of treatment, and IFNbeta-1a induced IFNgamma production by naive PBMC in vitro. We did not record increased numbers of IL-4 mRNA-expressing CSF-MC or PBMC, increased plasma IL-10 levels, increased numbers of IgG, A or M secreting plasma cells or in vitro induction of IL-10 production by IFNbeta-1a. We conclude that long-term cytokine modulation by IFNbeta-1a differs from acute effects and that downregulation of both pro- and anti-inflammatory cytokines, rather than a shift in the cytokine profile, is apparent after 6 months of IFNbeta-1a treatment of MS patients.

Expression of nonclassical MHC class I (RT1-U) in certain neuronal populations of the central nervous system

Major histocompatibility complex (MHC) class I genes consist of classical (Ia) and nonclassical (Ib) types. Recently, a set of structurally similar MHC class Ib genes in the rat, denoted RT1-U, was described. We here demonstrate expression of RT1-U mRNA using highly stringent oligonucleotide in situ hybridization in several different neuronal populations, including different motor nuclei and the substantia nigra in the rat MHC (c) and (n) haplotypes under normal conditions. The expression pattern for beta2-microglobulin mRNA was almost identical. In contrast, neuronal expression of classical MHC class I (RT1-A) was low. Interestingly, after mechanical nerve injury, glial cells predominantely upregulated expression of RT1-A, whereas neuronal expression of RT1-U remained unchanged. Neuronal expression of nonclassical MHC class I may thus be important for immune surveillance in the nervous system.

Expression of MHC class I heavy chain and beta2-microglobulin in rat brainstem motoneurons and nigral dopaminergic neurons

We demonstrate here that motoneurons and nigral dopaminergic neurons in the brainstem of the adult rat, with the exception of motoneurons innervating ocular muscles, display high levels of both MHC class I heavy chain and beta2-microglobulin mRNAs. These neurons also display interferon-gamma receptor mRNA. We find it striking that these particular neurons are those which are vulnerable to neurodegeneration in diseases such as Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS).

Non-MHC gene regulation of nerve root injury induced spinal cord inflammation and neuron death

Spinal ventral root avulsion leads to an inflammatory response around lesioned motoneurons and the subsequent degeneration of a large proportion of the neurons. We demonstrate here differences in the regulation of cytokine mRNAs, microglia/macrophage activation, MHC expression and nerve cell survival in the two inbred rat strains DA and ACI. These strains have similar major MHC haplotypes, but differ in their non-MHC background genes. T cells were rare in the lesioned segments and depletion of T cells did not affect the response. Thus, non-MHC gene(s) regulate the inflammation and neuron death after nerve trauma by mechanisms not involving antigen-specific immune responses.