Male Sex Is Independently Associated with Faster Disability Accumulation in Relapse-Onset MS but Not in Primary Progressive MS

Differential Transcription of SOCS5 and SOCS7 in Multiple Sclerosis Patients Treated with Interferon Beta or Glatiramer Acetate

The participation of proinflammatory cytokines in the progression of Multiple Sclerosis (MS) has been well documented. Cytokines activate the JAK-STAT pathway, in which the suppressors of cytokine signaling (SOCS) exert a negative feedback. This paper analyzes the levels of SOCS5 and SOCS7 transcripts, quantified by RT-qPCR, in MS patients, and the concentrations of proinflammatory cytokines, IFN-γ, IL17, and IL6, determined by ELISA. Samples of peripheral blood were obtained from MS patients in the relapsing–remitting phase, treated with IFN-β or glatiramer acetate (GA), and from healthy individuals. SOCS7 mRNA was significantly higher in patients treated with GA (1.36 ± 0.23) than in those treated with IFN-β (0.65 ± 0.1). Regarding gender, the level of SOCS5 and SOCS7 transcripts were similar between MS and healthy females; in MS males, the level of SOCS7 transcripts were significantly lower (0.59 ± 0.03) than in healthy males (1.008 ± 0.05). Plasmatic levels of IFN-γ were significantly higher in MS patients (60 pg/mL, range 0–160) than in healthy subjects (0 range, 0–106). The same pattern was observed in MS patients treated with IFN-β (68 pg/mL, range 0–160) compared to patients treated with GA (51 pg/mL, range 0–114), and in MS females (64 pg/mL, range 0–161) compared to healthy females (0, range 0–99). We hypothesize that the increase in SOCS7 transcription in patients treated with GA could partially explain the action mechanism of this drug, while the increase in the concentration of IFN-γ in MS patients could help elucidate the immunopathology of the disease.

Immune-inflammatory, metabolic and hormonal biomarkers are associated with the clinical forms and disability progression in patients with multiple sclerosis: A follow-up study

The objective of this study was to evaluate the role of immune-inflammatory, metabolic, hormonal, and oxidative stress biomarkers in disability progression (DP) and clinical forms of multiple sclerosis (MS). The study evaluated 140 MS patients at admission (T0), and eight (T8) and 16 months (T16) later. The Expanded Disability Status Score (EDSS) and biomarkers were determined at T0, T8, and T16. A DP index (DPI) defined as an increase of ≥1 rank on the EDSS score indicated that 39.3% of the patients had significant DP. Quantification of the ordinal EDSS rank score was performed using optimal scaling methods. Categorical regression showed that the quantitative T16 EDSS score was predicted by T0 homocysteine (Hcy), T0 parathormone (PTH), T0 advanced oxidized protein products (AOPP) (all positively), low T0 vitamin D (<18.3 ng/mL) and T8 folic acid (<5 ng/mL) concentrations while higher T8 calcium concentrations (≥8.90 mg/dL) had protective effects. Linear Mixed Models showed that the change in EDSS from T0 to T16 was significantly associated with changes in IL-17 (positively) and IL-4 (inversely) independently from the significant effects of clinical MS forms, treatment modalities, smoking, age and systemic arterial hypertension. Hcy, PTH, IL-6, and IL-4 were positively associated with progressive versus relapsing-remitting MS while 25(OH)D was inversely associated. In conclusion, the ordinal EDSS scale is an adequate instrument to assess DP after category value estestimation. Aberrations in immune-inflammatory, metabolic and hormonal biomarkers are associated with DP and with the progressive form of MS.

Computer-Aided Diagnosis of Multiple Sclerosis Using a Support Vector Machine and Optical Coherence Tomography Features

The purpose of this paper is to evaluate the feasibility of diagnosing multiple sclerosis (MS) using optical coherence tomography (OCT) data and a support vector machine (SVM) as an automatic classifier. Forty-eight MS patients without symptoms of optic neuritis and forty-eight healthy control subjects were selected. Swept-source optical coherence tomography (SS-OCT) was performed using a DRI (deep-range imaging) Triton OCT device (Topcon Corp., Tokyo, Japan). Mean values (right and left eye) for macular thickness (retinal and choroidal layers) and peripapillary area (retinal nerve fibre layer, retinal, ganglion cell layer—GCL, and choroidal layers) were compared between both groups. Based on the analysis of the area under the receiver operator characteristic curve (AUC), the 3 variables with the greatest discriminant capacity were selected to form the feature vector. A SVM was used as an automatic classifier, obtaining the confusion matrix using leave-one-out cross-validation. Classification performance was assessed with Matthew’s correlation coefficient (MCC) and the AUC_CLASSIFIER. The most discriminant variables were found to be the total GCL++ thickness (between inner limiting membrane to inner nuclear layer boundaries), evaluated in the peripapillary area and macular retina thickness in the nasal quadrant of the outer and inner rings. Using the SVM classifier, we obtained the following values: MCC = 0.81, sensitivity = 0.89, specificity = 0.92, accuracy = 0.91, and AUC_CLASSIFIER = 0.97. Our findings suggest that it is possible to classify control subjects and MS patients without previous optic neuritis by applying machine-learning techniques to study the structural neurodegeneration in the retina.

Redefining the Multiple Sclerosis Severity Score (MSSS): The effect of sex and onset phenotype

BACKGROUND

The Multiple Sclerosis Severity Score (MSSS) is a widely used measure of the disability progression rate. However, the global MSSS may not be the best basis for comparison between all patient groups.

OBJECTIVE

We evaluated sex-specific and onset phenotype-specific MSSS matrices to determine if they were more effective than the global MSSS as a basis for comparison within these subsets.

METHODS

Using a large international dataset of multiple sclerosis (MS) patient records and the original MSSS algorithm, we constructed global, sex-specific and onset phenotype-specific MSSS matrices. We compared matrices using permutation analysis.

RESULTS

Our final dataset included 30,203 MS cases, with 28.9% males and 6.5% progressive-onset cases. Our global MSSS matrix did not differ from previously published data (p > 0.05). The progressive-onset-specific matrix differed significantly from the relapsing-onset-specific matrix (p < 0.001), with lower MSSS attributed to cases with the same Expanded Disability Status Score (EDSS) and disease duration. When evaluated with a simulation, using an onset-specific MSSS improved statistical power in mixed cohorts. There were no significant differences by sex.

CONCLUSION

The differences in the disability accrual rate between progressive- and relapsing-onset MS have a significant effect on MSSS. An onset-specific MSSS should be used when comparing the rate of disability progression among progressive-onset cases and for mixed cohorts.

Dynamic response of microglia/macrophage polarization following demyelination in mice

BACKGROUND

The glial response in multiple sclerosis (MS), especially for recruitment and differentiation of oligodendrocyte progenitor cells (OPCs), predicts the success of remyelination of MS plaques and return of function. As a central player in neuroinflammation, activation and polarization of microglia/macrophages (M/M) that modulate the inflammatory niche and cytokine components in demyelination lesions may impact the OPC response and progression of demyelination and remyelination. However, the dynamic behaviors of M/M and OPCs during demyelination and spontaneous remyelination are poorly understood, and the complex role of neuroinflammation in the demyelination-remyelination process is not well known. In this study, we utilized two focal demyelination models with different dynamic patterns of M/M to investigate the correlation between M/M polarization and the demyelination-remyelination process.

METHODS

The temporal and spatial features of M/M activation/polarization and OPC response in two focal demyelination models induced by lysolecithin (LPC) and lipopolysaccharide (LPS) were examined in mice. Detailed discrimination of morphology, sensorimotor function, diffusion tensor imaging (DTI), inflammation-relevant cytokines, and glial responses between these two models were analyzed at different phases.

RESULTS

The results show that LPC and LPS induced distinctive temporal and spatial lesion patterns. LPS produced diffuse demyelination lesions, with a delayed peak of demyelination and functional decline compared to LPC. Oligodendrocytes, astrocytes, and M/M were scattered throughout the LPS-induced demyelination lesions but were distributed in a layer-like pattern throughout the LPC-induced lesion. The specific M/M polarization was tightly correlated to the lesion pattern associated with balance beam function.

CONCLUSIONS

This study elaborated on the spatial and temporal features of neuroinflammation mediators and glial response during the demyelination-remyelination processes in two focal demyelination models. Specific M/M polarization is highly correlated to the demyelination-remyelination process probably via modulations of the inflammatory niche, cytokine components, and OPC response. These findings not only provide a basis for understanding the complex and dynamic glial phenotypes and behaviors but also reveal potential targets to promote/inhibit certain M/M phenotypes at the appropriate time for efficient remyelination.

The rs3761548 FOXP3 variant is associated with multiple sclerosis and transforming growth factor β1 levels in female patients

OBJECTIVE

The aim of this study was to evaluate the association between rs3761548 FOXP3 (-3279 C > A) variant and multiple sclerosis (MS), disability, disability progression, as well as transforming growth factor (TGF)-β1 and interleukin (IL)-10 plasma levels in MS patients.

METHODS AND SUBJECTS

The study included 170 MS patients and 182 controls. Disability was evaluated using Expanded Disability Status Scale (EDSS) and categorized as mild (EDSS ≤ 3) and moderate/high (EDSS > 3). Disability progression was evaluated using Multiple Sclerosis Severity Score (MSSS). The rs3761548 variant was determined with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Plasma levels of TGF-β1 and IL-10 were determined using immunofluorimetric assay.

RESULTS

CA and AA genotypes were associated with MS [odds ratio (OR) 2.03, 95% confidence interval (CI) 1.66-3.53, p = 0.012; OR 8.19, 95% CI 3.04-22.07, p < 0.001, respectively). With the dominant model, the CA + AA genotypes were associated with MS (OR 2.57, 95% CI 1.50-4.37, p < 0.001). In the recessive model, the AA genotype was also associated with MS (OR 5.38, 95% CI 2.12-13.64, p < 0.001). After adjustment by age, ethnicity, BMI and smoking, all these results remained significant, as well as female patients carrying the CA + AA genotypes showed higher TGF-β1 than those carrying the CC genotype (OR 1.35, 95% CI 1.001-1.054, p = 0.043). No association was observed between the genotypes and disability, disability progression and IL-10 levels.

CONCLUSION

These results suggest that the A allele of FOXP3 -3279 C > A variant may exert a role in the T regulatory cell function, which could be one of the factors involved in the susceptibility for MS in females.

The MSBase registry: Informing clinical practice

Over the last decade, clinical registries have significantly contributed to the pool of evidence that supports management decisions in patients with multiple sclerosis. Being the largest international registry of multiple sclerosis and neuroimmunological disorders, MSBase collects demographic, clinical and limited paraclinical information from patients managed in different regions and under various circumstances. In this review, we will provide an overview of its published output, with focus on the information with impact on the management of multiple sclerosis.

IL12B gene polymorphisms have sex-specific effects in relapsing-remitting multiple sclerosis

IL-12-family cytokines play a pivotal role in neuroinflammation and neurodegeneration in relapsing-remitting multiple sclerosis (RRMS). The aim of the study was to evaluate whether two polymorphisms in IL12B gene, rs17860508 and rs3212227, are associated with RRMS, and to define their function effect on serum level of IL-12p40 and IL-23 and degree of disability in RRMS cases. In total 156 Bulgarian patients with Expanded Disability Status Scale score ranging from 1.0 to 3.5 in remission of the disease and 379 controls were genotyped by polymerase chain reaction-based methods. The IL-12p40 and IL-23 serum levels were determined by enzyme-linked immunosorbent assay. We have found substantially higher IL-12p40 and IL-23 serum levels in cases than in controls (p < 0.01) in a sex-dependent manner. Women with RRMS had significantly higher IL-12р40 and IL-23 than men. Gender-stratified association analyses showed a significant impact of rs3212227 polymorphism on RRMS susceptibility in men. The carriers of rs3212227*CC-genotype (OR 3.390, 95% CI 1.007-11.545, p = 0.023) and haplotype rs17860508*2-allele/rs3212227*C-allele (OR 3.740; 95% CI 1.36-10.32, p = 0.007), showed higher risk of RRMS in men, in contrast to women. In women, both IL12B polymorphisms influencing the course, rather than genetic predisposition of RRMS. The rs17860508*22-genotype was associated with significantly lower disability (OR 0.208; 95% CI 0.055-0.725; p_c = 0.01) and lower IL-23 serum levels (p = 0.0345), while rs3212227*AA-genotype was associated with early onset of the disease (OR 2.368; 95% CI 1.007-5.608; p = 0.03). Our results suggest that sex-specific effects of IL12B polymorphisms, rs17860508 and rs3212227, on genetic predisposition and disease course of RRMS, is probably mediated by their gender-dependent functional effect on IL-12p40-containing cytokines.

The neutrophil-to-lymphocyte and monocyte-to-lymphocyte ratios are independently associated with neurological disability and brain atrophy in multiple sclerosis

BACKGROUND

Serum hematological indices such as the neutrophil-lymphocyte ratio (NLR) or monocyte-lymphocyte ratio (MLR) have been used as biomarkers of pathogenic inflammation and prognostication in multiple areas of medicine; recent evidence shows correlation with psychological parameters as well.

OBJECTIVES/AIMS

To characterize clinical, neuroimaging, and psycho-neuro-immunological associations with NLR and MLR in persons with multiple sclerosis (MS).

METHODS

We identified a large cohort of clinically well-defined patients from our longitudinal database that included MS-related outcomes, disease-modifying therapy, patient-reported outcome (PRO) measures, and quantified cerebral MRI at 1.5 T. We queried hospital records for complete blood counts within 2 months of each clinic visit and excluded those obtained during clinical relapses. Four hundred eighty-three patients, with a mean of 3 longitudinal observations each, were identified who met these criteria. Initial analyses assessed the association between NLR and MLR as the outcomes, and psychological and demographic predictors in univariable and multivariable models controlling for age, gender and treatment. The second set of analyses assessed the association between clinical and MRI outcomes including whole brain atrophy and T2-hyperintense lesion volume, with NLR and MLR as predictors in univariable and multivariable models. All analyses used a mixed effects linear or logistic regression model with repeated measures.

RESULTS

Unadjusted analyses demonstrated significant associations between higher (log-transformed) NLR (but not MLR) and PRO measures including increasing depression (p = 0.01), fatigue (p < 0.01), and decreased physical quality of life (p < 0.01). Higher NLR and MLR strongly predicted increased MS-related disability as assessed by the Expanded Disability Status Scale, independent of all demographic, clinical, treatment-related, and psychosocial variables (p < 0.001). Lastly, higher NLR and MLR significantly discriminated progressive from relapsing status (p ≤ 0.01 for both), and higher MLR correlated with increased whole-brain atrophy (p < 0.05) but not T2 hyperintense lesion volume (p > 0.05) even after controlling for all clinical and demographic covariates. Sensitivity analyses using a subset of untreated patients (N = 146) corroborated these results.

CONCLUSIONS

Elevated NLR and MLR may represent hematopoetic bias toward increased production and pro-inflammatory priming of the myeloid innate immune system (numerator) in conjunction with dysregulated adaptive immune processes (denominator), and consequently reflect a complementary and independent marker for severity of MS-related neurological disability and MRI outcomes.

Impact of sex hormones on immune function and multiple sclerosis development

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) affecting young people and leading to demyelination and neurodegeneration. The disease is clearly more common in women, in whom incidence has been rising. Gender differences include: earlier disease onset and more frequent relapses in women; and faster progression and worse outcomes in men. Hormone-related physiological conditions in women such as puberty, pregnancy, puerperium, and menopause also exert significant influence both on disease prevalence as well as on outcomes. Hormonal and/or genetic factors are therefore believed to be involved in regulating the course of disease. In this review, we discuss clinical evidence for the impact of sex hormones (estrogens, progesterone, prolactin, and testosterone) on MS and attempt to elucidate the hormonal and immunological mechanisms potentially underlying these changes. We also review current knowledge on the relationship between sex hormones and resident CNS cells and provide new insights in the context of MS. Understanding these molecular mechanisms may contribute to the development of new and safer treatments for both men and women.

Sex differences in autoimmune disorders of the central nervous system

Stronger adaptive immune responses in females can be observed in different mammals, resulting in better control of infections compared to males. However, this presumably evolutionary difference likely also drives higher incidence of autoimmune diseases observed in humans. Here, we summarize sex differences in the most common autoimmune diseases of the central nervous system (CNS) and discuss recent advances in the understanding of possible underlying immunological and CNS intrinsic mechanisms. In multiple sclerosis (MS), the most common inflammatory disease of the CNS, but also in rarer conditions, such as neuromyelitis optica spectrum disorders (NMOSD) or neuronal autoantibody-mediated autoimmune encephalitis (AE), sex is one of the top risk factors, with women being more often affected than men. Immunological mechanisms driving the sex bias in autoimmune CNS diseases are complex and include hormonal as well as genetic and epigenetic effects, which could also be exerted indirectly via modulation of the microbiome. Furthermore, CNS intrinsic differences could underlie the sex bias in autoimmunity by differential responses to injury. The strong effects of sex on incidence and possibly also activity and progression of autoimmune CNS disorders suggest that treatments need to be tailored to each sex to optimize efficacy. To date, however, due to a lack of systematic studies on treatment responses in males versus females, evidence in this area is still sparse. We argue that studies taking sex differences into account could pave the way for sex-specific and therefore personalized treatment.

Estimation of annual probabilities of changing disability levels in Australians with relapsing-remitting multiple sclerosis

BACKGROUND

Transition probabilities are the engine within many health economics decision models. However, the probabilities of progression of disability due to multiple sclerosis (MS) have not previously been estimated in Australia.

OBJECTIVES

To estimate annual probabilities of changing disability levels in Australians with relapsing-remitting MS (RRMS).

METHODS

Combining data from Ausimmune/Ausimmune Longitudinal (2003-2011) and Tasmanian MS Longitudinal (2002-2005) studies (n = 330), annual transition probabilities were obtained between no/mild (Expanded Disability Status Scale (EDSS) levels 0-3.5), moderate (EDSS 4-6.0) and severe (EDSS 6.5-9.5) disability.

RESULTS

From no/mild disability, 6.4% (95% confidence interval (CI): 4.7-8.4) and 0.1% (0.0-0.2) progressed to moderate and severe disability annually, respectively. From moderate disability, 6.9% (1.0-11.4) improved (to no/mild state) and 2.6% (1.1-4.5) worsened. From severe disability, 0.0% improved to moderate and no/mild disability. Male sex, age at onset, longer disease duration, not using immunotherapies greater than 3 months and a history of relapse were related to higher probabilities of worsening.

CONCLUSION

We have estimated probabilities of changing disability levels in Australians with RRMS. Probabilities differed between various subgroups, but due to small sample sizes, results should be interpreted with caution. Our findings will be helpful in predicting long-term disease outcomes and in health economic evaluations of MS.

Impact of trial design and patient heterogeneity on the identification of clinically effective therapies for progressive MS

Clinically effective immunomodulatory therapies have been developed for relapsing-remitting multiple sclerosis (RRMS), but they have generally not translated to a corresponding slowing of disability accumulation in progressive forms of multiple sclerosis (MS). Since disability is multifaceted, progressive patients are heterogeneous, and the drivers of disease progression are still unclear, it has been difficult to identify the most informative outcome measures for progressive trials. Historically, secondary outcome measures have focused on inflammatory measures, which contributed to the recent identification of immunomodulatory therapies benefiting younger patients with more inflammatory progressive MS. Meanwhile, agents capable of treating late-stage disease have remained elusive. Consequently, measures of neurodegeneration are becoming common. Here, we review completed clinical trials testing immunomodulatory therapies in primary progressive multiple sclerosis (PPMS) or secondary progressive multiple sclerosis (SPMS) and discuss the features contributing to trial design variability in relation to trial outcomes, and how efforts toward better patient stratification and inclusion of reliable progression markers could improve outcomes.

A case for gender-based approach to multiple sclerosis therapeutics

Despite established sex differences in multiple sclerosis (MS) risk and course, sex-specific efficacy and toxicity of existing MS therapies, and possible sex-specific therapeutic approaches, remain underexplored. We systematically reviewed published sex differences from Phase III pivotal trials for FDA or EMA-approved MS disease modifying therapies (DMTs), along with additional information from pharmaceutical companies, for pre-specified or post-hoc baseline characteristics, efficacy and safety outcomes by sex, and sex-specific concerns. Then, we reviewed trials testing hormonal therapies in MS. None of the Phase III clinical trials performed baseline sex-specific analyses or were powered to evaluated DMTs in menopausal/older populations. Some recent trials performed pre-specified or post-hoc stratification of outcomes by sex. Sex-specific hormonal intervention trials were limited. Adequately powered, pre-specified analyses accounting for baseline sex and age are required to maximize safety and efficacy in specific patient populations.

Sex chromosome contributions to sex differences in multiple sclerosis susceptibility and progression

BACKGROUND

Why are women more susceptible to multiple sclerosis, but men have worse disability progression? Sex differences in disease may be due to sex hormones, sex chromosomes, or both.

OBJECTIVE

Determine whether differences in sex chromosomes can contribute to sex differences in multiple sclerosis using experimental autoimmune encephalomyelitis.

METHODS

Sex chromosome transgenic mice, which permit the study of sex chromosomes not confounded by differences in sex hormones, were used to examine an effect of sex chromosomes on autoimmunity and neurodegeneration, focusing on X chromosome genes.

RESULTS

T-lymphocyte DNA methylation studies of the X chromosome gene Foxp3 suggested that maternal versus paternal imprinting of X chromosome genes may underlie sex differences in autoimmunity. Bone marrow chimeras with the same immune system but different sex chromosomes in the central nervous system suggested that differential expression of the X chromosome gene Toll-like receptor 7 in neurons may contribute to sex differences in neurodegeneration.

CONCLUSION

Mapping the transcriptome and methylome in T lymphocytes and neurons in females versus males could reveal mechanisms underlying sex differences in autoimmunity and neurodegeneration.

Evidence of progressive tissue loss in the core of chronic MS lesions: A longitudinal DTI study

Objective

Using diffusion tensor imaging (DTI), we examined chronic stable MS lesions, peri-lesional white matter (PLWM) and normal appearing white matter (NAWM) in patients with relapsing-remitting multiple sclerosis (RRMS) for evidence of progressive tissue destruction and evaluated whether diffusivity change is associated with conventional MRI parameters and clinical findings.

Method

Pre- and post-gadolinium T1, T2 and DTI images were acquired from 55 consecutive RRMS patients at baseline and 42.3 ± 9.7 months later. Chronic stable T2 lesions of sufficient size were identified in 43 patients (total of 134 lesions). Diffusivity parameters such as axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD) and fractional anisotropy (FA) were compared at baseline and follow-up. MRI was also performed in 20 normal subjects of similar age and gender.

Results

Within the core of chronic MS lesions the diffusion of water molecules significantly increased over the follow-up period, while in NAWM all diffusivity indices remained stable. Since increase of AD and RD in lesional core was highly concordant, indicating isotropic nature of diffusivity change, and considering potential effect of crossing fibers on directionally-selective indices, only MD, a directionally-independent measure, was used for further analysis. The significant increase of MD in the lesion core during the follow-up period (1.29 ± 0.19 μm2/ms and 1.34 ± 0.20 μm2/ms at baseline and follow-up respectively, P < 0.0001) was independent of age or disease duration, total brain lesion volume or new lesion activity, lesion size or location and baseline tissue damage (T1 hypointensity). Change of MD in the lesion core, however, was associated with progressive brain atrophy (r = 0.47, P = 0.002). A significant gender difference was also observed: the MD change in male patients was almost twice that of female patients (0.030 ± 0.04 μm2/ms and 0.058 ± 0.03 μm2/ms in female and male respectively, P = 0.01). Sub-analysis of lesions with lesion-free surrounding revealed the largest MD increase in the lesion core, while MD progression gradually declined towards PLWM. MD in NAWM remained stable over the follow-up period.

Conclusion

The significant increase of isotropic water diffusion in the core of chronic stable MS lesions likely reflects gradual, self-sustained tissue destruction in demyelinated white matter that is more aggressive in males.

The importance of studying sex differences in disease: The example of multiple sclerosis

To date, scientific research has often focused on one sex, with assumptions that study of the other sex would yield similar results. However, many diseases affect males and females differently. The sex of a patient can affect the risk for both disease susceptibility and progression. Such differences can be brought to the laboratory bench to be investigated, potentially bringing new treatments back to the clinic. This method of research, known as a "bedside to bench to bedside" approach, has been applied to studying sex differences in multiple sclerosis (MS). Females have greater susceptibly to MS, while males have worse disease progression. These two characteristics of the disease are influenced by the immune system and the nervous system, respectively. Thus, sex differences in each system must be studied. Personalized medicine has been at the forefront of research recently, and studying sex differences in disease fits with this initiative. This review will discuss the known sex differences in MS and highlight how investigating them can lead to new insights and potential treatments for both men and women. © 2016 Wiley Periodicals, Inc.

Long-lasting masculinizing effects of postnatal androgens on myelin governed by the brain androgen receptor

The oligodendrocyte density is greater and myelin sheaths are thicker in the adult male mouse brain when compared with females. Here, we show that these sex differences emerge during the first 10 postnatal days, precisely at a stage when a late wave of oligodendrocyte progenitor cells arises and starts differentiating. Androgen levels, analyzed by gas chromatography/tandem-mass spectrometry, were higher in males than in females during this period. Treating male pups with flutamide, an androgen receptor (AR) antagonist, or female pups with 5α-dihydrotestosterone (5α-DHT), revealed the importance of postnatal androgens in masculinizing myelin and their persistent effect into adulthood. A key role of the brain AR in establishing the sexual phenotype of myelin was demonstrated by its conditional deletion. Our results uncover a new persistent effect of postnatal AR signaling, with implications for neurodevelopmental disorders and sex differences in multiple sclerosis.

Sex differences in brain structure are of great scientific and medical interest because the incidence and progress of many neurological and psychiatric disorders differ between males and females. They affect neural networks and also the myelin sheaths that insulate and protect axons and thus allow the rapid conduction of electrical impulses. In the central nervous system, myelin is formed by a particular type of cells named oligodendrocytes. In the male mouse brain, the density of oligodendrocytes is greater and myelin sheaths are thicker when compared with females. We show that these sex differences in myelin result from the long-lasting actions of androgens in males during their first 10 postnatal days. Importantly, the postnatal masculinizing effects of androgens involve brain androgen receptors as shown by the use of pharmacological and genetic tools. These findings are important for understanding sex-related differences in the susceptibility and progression of demyelinating diseases such as multiple sclerosis. They also reveal a so far unknown role of androgen receptor signaling in sexual differentiation of the brain.

Male factor infertility and risk of multiple sclerosis: A register-based cohort study

Background:

Gender, possibly due to the influence of gonadal hormones, is presumed to play a role in the pathogenesis of multiple sclerosis (MS), but no studies have evaluated whether male infertility is associated with MS.

Objective:

To study the association between male factor infertility and prevalent as well as incident MS.

Method:

Our cohort was established by linkage of the Danish National in vitro fertilization (IVF) registry to The Danish Multiple Sclerosis Registry and consisted of 51,063 men whose partners had undergone fertility treatment in all public and private fertility clinics in Denmark between 1994 and 2015.

Results:

With a median age of 34 years at baseline, 24,011 men were diagnosed with male factor infertility and 27,052 did not have male factor infertility and made up the reference group. Men diagnosed with male factor infertility had a higher risk of prevalent (odds ratio (OR) = 1.61, 95% confidence interval (95% CI) 1.04–2.51) and incident MS (hazard ratio (HR) = 1.28, 95% CI 0.76–2.17) when compared to the reference group.

Conclusion:

This nationwide cohort study has shown, for the first time, an association between male infertility and MS which may be due to underlying common etiologies such as hypogonadism, shared genetics, or a joint autoimmune component.

Do gait patterns differ in men and women with multiple sclerosis?

BACKGROUND

Multiple Sclerosis (MS) affects men and women differently from several points of view: prevalence, severity of cognitive impairments and disability accumulation. However, it is unknown whether ambulatory dysfunctions are sex-related. This study investigated the existence of differences in spatio-temporal and kinematic parameters of gait in men and women with MS using 3D gait analysis.

METHODS

Gait patterns of 60 people with MS (pwMS, 32F, 28M) with low to moderate disability (average Expanded Disability Status Scale score 3, range 1-5.5) who underwent a gait analysis in the period 2014-2017 were retrospectively analyzed to calculate spatio-temporal parameters of gait and kinematics in the sagittal plane at hip, knee and ankle joints.

RESULTS

Significant differences between the groups were found in kinematics of gait. In particular, men exhibited reduced ankle plantar-flexion, increased knee flexion and hip flexion. In contrast, no differences were found in spatio-temporal parameters normalized by considering individuals' anthropometry.

CONCLUSIONS

The findings of the present study highlight the need to investigate gait dysfunctions in pwMS taking sex into consideration. Such an approach might be useful not only in better understanding the pathophysiology of gait disturbances originated by MS, but also in supporting a better orientation of rehabilitative treatments.

PLXNA3 Variant rs5945430 is Associated with Severe Clinical Course in Male Multiple Sclerosis Patients

Multiple sclerosis (MS) exhibits sex bias in disease clinical course as male MS patients develop severe, progressive clinical course with accumulating disability. So far, no factors have been found associating with this sex bias in MS severity. We set out to determine the genetic factor contributing to MS male-specific progressive disease. This is an MS cross-sectional study involving 213 Kuwaiti MS patients recruited at Dasman Diabetes Institute. Exome sequencing was performed on 18 females and 8 male MS patients' genomic DNA. rs5945430 genotyping was performed using Taqman genotyping assay. Estradiol levels were determined by enzyme-linked immunosorbent assay. Exome analysis revealed a missense variant (rs5945430) in Plexin A3 (PLXNA3) gene (Xq28) associated with male-specific MS severity. Genotyping of 187 MS patients for rs5945430 confirmed the association of rs5945430G with increased disease severity in MS males (p = 0.013; OR 3.8; 95% CI 1.24-11.7) and disability (p = 0.024). Estradiol levels shown to effect PLXNA3 expression were lower in MS males compared to MS females, and they were lower than control rs5945430G males (p = 0.057), whereas MS females had similar estradiol levels to healthy females reducing the level of expressed PLXNA3 GG in MS females. PLXNA3 rs5945430G is associated with increased disease severity in MS male patients. Estradiol is a possible protective factor against the expression of rs5945430G in MS females.

Symptomatic treatment in multiple sclerosis-interim analysis of a nationwide registry

OBJECTIVE

To analyze symptomatic treatment in patients with multiple sclerosis (MS).

BACKGROUND

Multiple sclerosis is a chronic inflammatory disease of the central nervous system, with accumulating disability symptoms like spasticity, voiding disorders, depression, and pain might occur.

MATERIAL AND METHODS

The nationwide German MS registry was initiated 2001 under guidance of the German MS society (Deutsche MS Gesellschaft). This study was performed as an interim analysis to lay foundation for future work on this topic. A subcohort of 5113 patients was assessed for this interim analysis. The mean age of the patients was 45.3 years; mean EDSS was 4.2. More than two-third of the enrolled patients were females (70.9%).

RESULTS

Most frequent symptoms were fatigue (60%), followed by spasticity (52.5%) and voiding disorders (51.7%). The likelihood of treatment was highest for epileptic disorders (68.8%), spasticity (68.5%), pain (60.7%), and depression (58.9%). Multivariate regression analysis showed that retirement was the strongest factor predictive for antispastic treatment (β=.061, P=.005).

CONCLUSION

Almost all patients in this analysis suffer from symptoms due to advanced MS. Treatment for the various symptoms differed tremendously. The likelihood of treatment correlated with the availability of effective therapeutic agents. Clinicians should put more awareness on MS symptoms. Symptomatic treatment may improve quality of life.

Is Time to Reach EDSS 6.0 Faster in Patients with Late-Onset versus Young-Onset Multiple Sclerosis?

BACKGROUND & OBJECTIVES

Published natural history data on late-onset of multiple sclerosis are limited. We aimed to assess the risk of attaining EDSS 6.0 among patients with late-onset (> 40 years) MS (LOMS) and young-onset (18-40 years) MS (YOMS).

METHODS

This cross-sectional cohort study was conducted to identify LOMS and YOMS patients' with relapsing remitting course at MS diagnosis. Time (years) to reach sustained EDSS 6.0 was compared between LOMS and AOMS patients. Cox proportional hazards model was used to evaluate the demographic and clinical predictors of time to EDSS 6.0 in these cohorts.

RESULTS

LOMS and YOMS cohorts comprised 99 (10.7%) and 804 (89.3%) patients respectively. Spinal cord presentation at MS onset was more common among LOMS patients (46.5% vs. 32.3%). The proportions of LOMS and YOMS patients reaching EDSS 6.0 during the follow-up period were 19.2% and 15.7% respectively. In multivariable Cox proportional hazards model, older age at MS onset (adjusted hazard ratio (aHR) = 3.96; 95% CI: 2.14-7.32; p < 0.001), male gender (aHR = 1.85; 95% CI: 1.22-2.81; p = 0.004) and spinal cord presentation at onset (aHR = 1.47; 95% CI: 0.98-2.21; p = 0.062) were significantly associated with shorter time to EDSS 6.0.

CONCLUSIONS

LOMS patients attained EDSS 6.0 in a significantly shorter period that was influenced by male gender and spinal cord presentation at MS onset.

Increased regional gray matter atrophy and enhanced functional connectivity in male multiple sclerosis patients

Evidence suggests that sex/gender is an important factor for understanding multiple sclerosis (MS) and that some of its neuropathological consequences might manifest earlier in males. In the present study, we assessed gray matter (GM) volume and functional connectivity (FC) in a sample of female and male MS patients (MSp) and female and male healthy controls (HCs). As compared to female MSp, male MSp showed decreased GM volume in the bilateral frontal areas and increased FC between different brain regions. Because both sets of changes correlated significantly and no differences in cognitive performance were observed, we suggest that the FC increase observed in male MSp acts as a compensatory mechanism for their more extensive GM loss and that it promotes a functional convergence between male- and female-MSp.

Defining secondary progressive multiple sclerosis

A number of studies have been conducted with the onset of secondary progressive multiple sclerosis as an inclusion criterion or an outcome of interest. However, a standardized objective definition of secondary progressive multiple sclerosis has been lacking. The aim of this work was to evaluate the accuracy and feasibility of an objective definition for secondary progressive multiple sclerosis, to enable comparability of future research studies. Using MSBase, a large, prospectively acquired, global cohort study, we analysed the accuracy of 576 data-derived onset definitions for secondary progressive multiple sclerosis and first compared these to a consensus opinion of three neurologists. All definitions were then evaluated against 5-year disease outcomes post-assignment of secondary progressive multiple sclerosis: sustained disability, subsequent sustained progression, positive disability trajectory, and accumulation of severe disability. The five best performing definitions were further investigated for their timeliness and overall disability burden. A total of 17 356 patients were analysed. The best definition included a 3-strata progression magnitude in the absence of a relapse, confirmed after 3 months within the leading Functional System and required an Expanded Disability Status Scale step ≥4 and pyramidal score ≥2. It reached an accuracy of 87% compared to the consensus diagnosis. Seventy-eight per cent of the identified patients showed a positive disability trajectory and 70% reached significant disability after 5 years. The time until half of all patients were diagnosed was 32.6 years (95% confidence interval 32-33.6) after disease onset compared with the physicians' diagnosis at 36 (35-39) years. The identified patients experienced a greater disease burden [median annualized area under the disability-time curve 4.7 (quartiles 3.6, 6.0)] versus non-progressive patients [1.8 (1.2, 1.9)]. This objective definition of secondary progressive multiple sclerosis based on the Expanded Disability Status Scale and information about preceding relapses provides a tool for a reproducible, accurate and timely diagnosis that requires a very short confirmation period. If applied broadly, the definition has the potential to strengthen the design and improve comparability of clinical trials and observational studies in secondary progressive multiple sclerosis.

Progressive Injury in Chronic Multiple Sclerosis Lesions Is Gender-Specific: A DTI Study

Objective

To evaluate the longitudinal integrity of white matter tracts in patients with relapsing remitting multiple sclerosis (RRMS) as determined by changes in diffusivity indices of lesional and non-lesional white matter in the optic radiation over 12 months.

Methods

The optic radiation (OR) was identified in sixty RRMS patients using probabilistic tractography. MS lesions were segmented on FLAIR T2 images and a lesion mask was intersected with the co-registered OR. Lesions within the OR were identified in 39 patients. Voxel-based analysis of axial diffusivity (AD) and radial diffusivity (RD) within OR lesions and non-lesional normal appearing white matter (NAWM) was performed at baseline and 12 months in 34 patients (five patients excluded due to new OR lesions).

Results

Both RD and AD demonstrated much higher values within the lesions compared with non-lesional NAWM. There was a significant (p<0.001) increase of lesional AD and RD during the follow-up period. This increase, however, was driven almost entirely by the male cohort, in which a significantly greater change in both AD (M-2.7%, F-0.9%) and RD (M-4.6%, F-0.7%) was observed during the follow-up period. Non-lesional NAWM also demonstrated an increase in both AD and RD, albeit on a much lesser scale (1.0% and 0.6% respectively). In contradistinction to lesions, the diffusivity change in non-lesional NAWM was similar between sexes.

Conclusions

The evolution of AD and RD in chronic MS lesions over 12 months suggests ongoing inflammatory demyelinating activity accompanied by axonal loss. In addition, our findings are consistent with the recently observed trend of more rapid clinical progression in males and establish a potential in vivo biomarker of gender dichotomy by demonstrating a significantly faster rate of microstructural change in the chronic lesions of male patients with MS.