Pathogenesis of pediatric multiple sclerosis

Pediatric Multiple Sclerosis: Changing the Trajectory of Progression

PURPOSE OF REVIEW

Multiple sclerosis is a chronic inflammatory disease of the central nervous system. When seen in children and adolescents, crucial stages of brain development and maturation may be affected. Prompt recognition of multiple sclerosis in this population is essential, as early intervention with disease-modifying therapies may change developmental trajectories associated with the disease. In this paper, we will review diagnostic criteria for pediatric multiple sclerosis, outcomes, differential diagnosis, and current therapeutic approaches.

RECENT FINDINGS

Recent studies have demonstrated the utility of newer structural and functional metrics in facilitating early recognition and diagnosis of pediatric MS. Knowledge about disease-modifying therapies in pediatric multiple sclerosis has expanded in recent years: important developmental impacts of earlier therapeutic intervention and use of highly effective therapies have been demonstrated. Pediatric MS is characterized by highly active disease and high disease burden. Advances in knowledge have led to early identification, diagnosis, and treatment. Lifestyle-related interventions and higher efficacy therapies are currently undergoing investigation.

Interim guidelines for the assessment and treatment of pain in children with multiple sclerosis

Introduction

Pain in multiple sclerosis (MS) is common, but literature on pain in children with MS remains scarce. Pain has physical, psychological, and social implications in MS, and both comprehensive assessment and interdisciplinary management approaches are needed. We sought to develop an interdisciplinary interim guideline for the assessment and management of pain in children with MS.

Methods and materials

We convened a modified Delphi panel composed of 13 experts in pediatric and adult MS neurology, physiotherapy, pain, patient lived-experience, advanced practice nursing, psychology, physiatry, and MS research. A survey was sent to panelists for anonymous completion. The panel discussed survey themes extracted by the panel chair. The process was repeated twice.

Results

Thirteen assessment and treatment recommendations were produced regarding pain in children with MS.

Discussion

Future studies will assess implementation of these pain assessment and treatment guidelines in the clinical setting.

Ocrelizumab in pediatric multiple sclerosis

BACKGROUND

Ocrelizumab is a recombinant humanized anti-CD20 monoclonal IgG1, approved by FDA and EMA for adult patients with multiple sclerosis (MS). The data on the efficacy and safety of Ocrelizumab for pediatric MS cases are limited.

OBJECTIVE

Here, we describe pediatric relapsing-remitting MS (P-RRMS) cases who were treated with Ocrelizumab as a disease-modifying drug.

METHOD

P-RRMS cases who were started Ocrelizumab below 18 years-of-age and followed-up >12 months with Ocrelizumab treatment were included. The primary end-points were annualized relapse rate (ARR) and magnetic resonance imaging (MRI) activity (new/enlarging T2 lesions and new gadolinium (Gd) enhancing lesions). The secondary end-points were the percentage of patients who remain relapse-free and/or free from Gd enhancing lesions, Expanded Disability Status Scale (EDSS) score, and the safety profile of Ocrelizumab.

RESULTS

Of 18 P-RRMS cases receiving Ocrelizumab, 10 patients fulfilled the inclusion criteria for our study. The median duration of follow-up under Ocrelizumab was 28,3 months (min: 15 months, max: 46 months). Mean ARR decreased from 2.01 (±0.71) to 0 during the follow-up of Ocrelizumab treatment (P < 0.0001). None of the patients had MRI activity during the treatment. Mean EDSS decreased from 1.75 (±1.09) to 1.20 (±0.63) from the initiation of Ocrelizumab to the last follow-up of the patients (P = 0.024). None of the patients had serious side effects, except one patient who experienced anaphylaxis.

CONCLUSION

Ocrelizumab can be considered a safe and effective treatment option in highly active P-RRMS.

Needs and Experiences of Children and Adolescents with Pediatric Multiple Sclerosis and Their Caregivers: A Systematic Review

In the present study we conduct a systematic review to evaluate the needs and experience of people with pediatric multiple sclerosis (MS) and their caregivers. The literature search was conducted across 10 academic databases, adhering to PRISMA-P guidelines. Quality appraisal was conducted using the mixed method appraisal test for individual studies, and GRADE-CERQual to establish overall confidence of findings. Results were analyzed using a process of narrative synthesis. We identified 26 studies which included 2253 children/adolescents with MS (CAMS) and 1608 caregivers. MS was reported to negatively impact experiences for CAMS in domains such as of school performance, social relationships, mental health, and overall physical functioning. Specifically, fatigue and social support were reported as the most important barriers and facilitators for CAMS, respectively. In terms of caregiver experience, negative impacts were reported on social functioning, mental health, and quality of life. Additionally, lack of awareness concerning MS was one of the biggest challenges reported. Caregivers expressed needs for psychological and social support. This study provides the first evidence regarding the needs and experiences of CAMS and their caregivers. Findings can be used to address policy gaps for supporting families affected by pediatric MS.

Current Advances in Pediatric Onset Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune inflammatory disease affecting the central nervous system leading to demyelination. MS in the pediatric population is rare, but has been shown to lead to significant disability over the duration of the disease. As we have learned more about pediatric MS, there has been a development of improved diagnostic criteria leading to earlier diagnosis, earlier initiation of disease-modifying therapies (DMT), and an increasing number of DMT used in the treatment of pediatric MS. Over time, treatment with DMT has trended towards the initiation of higher efficacy treatment at time of diagnosis to help prevent further disease progression and accrual of disability over time, and there is evidence in current literature that supports this change in treatment patterns. In this review, we discuss the current knowledge in diagnosis, treatment, and clinical outcomes in pediatric MS.

Combined microRNA and mRNA expression analysis in pediatric multiple sclerosis: an integrated approach to uncover novel pathogenic mechanisms of the disease

Multiple sclerosis (MS) is a complex disease of the CNS that usually affects young adults, although 3-5% of cases are diagnosed in childhood and adolescence (hence called pediatric MS, PedMS). Genetic predisposition, among other factors, seems to contribute to the risk of the onset, in pediatric as in adult ages, but few studies have investigated the genetic 'environmentally naïve' load of PedMS. The main goal of this study was to identify circulating markers (miRNAs), target genes (mRNAs) and functional pathways associated with PedMS; we also verified the impact of miRNAs on clinical features, i.e. disability and cognitive performances. The investigation was performed in 19 PedMS and 20 pediatric controls (PCs) using a High-Throughput Next-generation Sequencing (HT-NGS) approach followed by an integrated bioinformatics/biostatistics analysis. Twelve miRNAs were significantly upregulated (let-7a-5p, let-7b-5p, miR-25-3p, miR-125a-5p, miR-942-5p, miR-221-3p, miR-652-3p, miR-182-5p, miR-185-5p, miR-181a-5p, miR-320a, miR-99b-5p) and 1 miRNA was downregulated (miR-148b-3p) in PedMS compared with PCs. The interactions between the significant miRNAs and their targets uncovered predicted genes (i.e. TNFSF13B, TLR2, BACH2, KLF4) related to immunological functions, as well as genes involved in autophagy-related processes (i.e. ATG16L1, SORT1, LAMP2) and ATPase activity (i.e. ABCA1, GPX3). No significant molecular profiles were associated with any PedMS demographic/clinical features. Both miRNAs and mRNA expressions predicted the phenotypes (PedMS-PC) with an accuracy of 92% and 91%, respectively. In our view, this original strategy of contemporary miRNA/mRNA analysis may help to shed light in the genetic background of the disease, suggesting further molecular investigations in novel pathogenic mechanisms.

Investigating the Role of MicroRNA and Transcription Factor Co-regulatory Networks in Multiple Sclerosis Pathogenesis

MicroRNAs (miRNAs) and transcription factors (TFs) play key roles in complex multifactorial diseases like multiple sclerosis (MS). Starting from the miRNomic profile previously associated with a cohort of pediatric MS (PedMS) patients, we applied a combined molecular and computational approach in order to verify published data in patients with adult-onset MS (AOMS). Six out of the 13 selected miRNAs (miR-320a, miR-125a-5p, miR-652-3p, miR-185-5p, miR-942-5p, miR-25-3p) were significantly upregulated in PedMS and AOMS patients, suggesting that they may be considered circulating biomarkers distinctive of the disease independently from age. A computational and unbiased miRNA-based screening of target genes not necessarily associated to MS was then performed in order to provide an extensive view of the genetic mechanisms underlying the disease. A comprehensive MS-specific miRNA-TF co-regulatory network was hypothesized; among others, SP1, RELA, NF-κB, TP53, AR, MYC, HDAC1, and STAT3 regulated the transcription of 61 targets. Interestingly, NF-κB and STAT3 cooperatively regulate the expression of immune response genes and control the cross-talk between inflammatory and immune cells. Further functional analysis will be performed on the identified critical hubs. Above all, in our view, this approach supports the need of multidisciplinary strategies for shedding light into the pathogenesis of MS.

Distinct effects of obesity and puberty on risk and age at onset of pediatric MS

Objective

The aim of this study was to examine the relative contributions of body mass index (BMI) and pubertal measures for risk and age of onset of pediatric MS.

Methods

Case–control study of 254 (63% female) MS cases (onset<18 years of age) and 420 (49% female) controls conducted at 14 U.S. Pediatric MS Centers. Sex‐ and age‐stratified BMI percentiles were calculated using CDC growth charts from height and weight measured at enrollment for controls, and within 1 year of onset for MS cases. Sex‐stratified associations between MS risk and age at symptom onset with both BMI and pubertal factors were estimated controlling for race and ethnicity.

Results

Only 11% of girls and 15% of boys were prepubertal (Tanner stage I) at MS onset. 80% of girls had onset of MS after menarche. BMI percentiles were higher in MS cases versus controls (girls: P < 0.001; boys: P = 0.018). BMI was associated with odds of MS in multivariate models in postpubertal girls (OR = 1.60, 95% confidence interval [CI]: 1.12, 2.27, P = 0.009) and boys (OR = 1.43, 95% CI: 1.08, 1.88, P = 0.011). In girls with MS onset after menarche, higher BMI was associated with younger age at first symptoms (P = 0.031). Younger menarche was associated with stronger effects of BMI through mediation and interaction analysis. In pubertal/postpubertal boys, 89% of whom were obese/overweight, earlier sexual maturity was associated with earlier onset of MS (P < 0.001).

Interpretation

Higher BMI in early adolescence is a risk factor for MS in girls and boys. Earlier age at sexual maturity contributes to earlier age at MS onset, particularly in association with obesity.

Pediatric-Onset Multiple Sclerosis Disease Progression in Kuwait: A Retrospective Analysis

BACKGROUND

Pediatric and adults patients share basic aspects of multiple sclerosis; however, pediatric patients may have distinctive clinical features and disease course.

OBJECTIVE

To compare the demographic and clinical characteristics between patients of pediatric-onset and adult-onset multiple sclerosis.

METHODS

Using the Kuwait National Multiple Sclerosis Registry , multiple sclerosis patients with disease onset at age ≤ 17 years (pediatric-onset multiple sclerosis) or >17 years (adult-adult multiple sclerosis) were identified. Several demographics and clinical characteristics were analyzed. Disability measures and time to reach secondary progressive multiple sclerosis were compared between the two cohorts using chi-square and Student t tests.

RESULTS

A total of 984 records of multiple sclerosis patients were assessed, of which 111 (11.3%) had disease onset at age ≤ 17 years. The female to male ratio did not differ between the two groups (P = 0.19). The mean age at onset of pediatric- and adult-onset multiple sclerosis was 14.9 and 27.68 years, respectively. Pediatric-onset multiple sclerosis patients were more likely to have brainstem/cerebellar (P < 0.03) and multifocal (P < 0.01) presentations at onset. The mean number of relapses did not differ between the two cohorts (3.4 ± 2.1 versus 3.05 ± 2.2; P = 0.14). The mean expanded disability status scale score at last visit was lower in the pediatric-onset cohort compared with the adult-onset cohort (2.38 ± 1.72 versus 3.02 ± 2.18; P = 0.003). The time to develop secondary progressive multiple sclerosis was longer in the pediatric-onset cohort (14.6 ± 4.6 years versus 11.0 ± 5.3 years; P < 0.04).

CONCLUSIONS

Pediatric-onset multiple sclerosis patients were more likely to have brainstem/cerebellar and multifocal symptoms at onset. Although the number of relapses was comparable to the adult-onset cohort, multiple sclerosis patients with pediatric-onset had lower expanded disability status scale scores and a longer time to reach secondary progressive course at last follow-up visits.

The US Network of Pediatric Multiple Sclerosis Centers: Development, Progress, and Next Steps

Multiple sclerosis and other demyelinating diseases in the pediatric population have received an increasing level of attention by clinicians and researchers. The low incidence of these diseases in children creates a need for the involvement of multiple clinical centers in research efforts. The Network of Pediatric Multiple Sclerosis Centers was created initially in 2006 to improve the diagnosis and care of children with demyelinating diseases. In 2010, the Network shifted its focus to multicenter research while continuing to advance the care of patients. The Network has obtained support from the National Multiple Sclerosis Society, the Guthy-Jackson Charitable Foundation, and the National Institutes of Health. The Network will continue to serve as a platform for conducting impactful research in pediatric demyelinating diseases of the central nervous system. This article provides a description of the history and development, organization, mission, research priorities, current studies, and future plans of the Network.

Reprogramming of HUVECs into induced pluripotent stem cells (HiPSCs), generation and characterization of HiPSC-derived neurons and astrocytes

Neurodegenerative diseases are characterized by chronic and progressive structural or functional loss of neurons. Limitations related to the animal models of these human diseases have impeded the development of effective drugs. This emphasizes the need to establish disease models using human-derived cells. The discovery of induced pluripotent stem cell (iPSC) technology has provided novel opportunities in disease modeling, drug development, screening, and the potential for “patient-matched” cellular therapies in neurodegenerative diseases. In this study, with the objective of establishing reliable tools to study neurodegenerative diseases, we reprogrammed human umbilical vein endothelial cells (HUVECs) into iPSCs (HiPSCs). Using a novel and direct approach, HiPSCs were differentiated into cells of central nervous system (CNS) lineage, including neuronal, astrocyte and glial cells, with high efficiency. HiPSCs expressed embryonic genes such as nanog, sox2 and Oct-3/4, and formed embryoid bodies that expressed markers of the 3 germ layers. Expression of endothelial-specific genes was not detected in HiPSCs at RNA or protein levels. HiPSC-derived neurons possess similar morphology but significantly longer neurites compared to primary human fetal neurons. These stem cell-derived neurons are susceptible to inflammatory cell-mediated neuronal injury. HiPSC-derived neurons express various amino acids that are important for normal function in the CNS. They have functional receptors for a variety of neurotransmitters such as glutamate and acetylcholine. HiPSC-derived astrocytes respond to ATP and acetylcholine by elevating cytosolic Ca²⁺ concentrations. In summary, this study presents a novel technique to generate differentiated and functional HiPSC-derived neurons and astrocytes. These cells are appropriate tools for studying the development of the nervous system, the pathophysiology of various neurodegenerative diseases and the development of potential drugs for their treatments.

Environmental factors in multiple sclerosis

Although multiple sclerosis (MS) is recognized as a disorder involving the immune system, the interplay of environmental factors and individual genetic susceptibility seems to influence MS onset and clinical expression, as well as therapeutic responsiveness. Multiple human epidemiological and animal model studies have evaluated the effect of different environmental factors, such as viral infections, vitamin intake, sun exposure, or still dietary and life habits on MS prevalence. Previous Epstein-Barr virus infection, especially if this infection occurs in late childhood, and lack of vitamin D (VitD) currently appear to be the most robust environmental factors for the risk of MS, at least from an epidemiological standpoint. Ultraviolet radiation (UVR) activates VitD production but there are also some elements supporting the fact that insufficient UVR exposure during childhood may represent a VitD-independent risk factor of MS development, as well as negative effect on the clinical and radiological course of MS. Recently, there has been a growing interest in the gut-brain axis, a bidirectional neuro-hormonal communication system between the intestinal microbiota and the central nervous system (CNS). Indeed, components of the intestinal microbiota may be pro-inflammatory, promote the migration of immune cells into the CNS, and thus be a key parameter for the development of autoimmune disorders such as MS. Interestingly most environmental factors seem to play a role during childhood. Thus, if childhood is the most fragile period to develop MS later in life, preventive measures should be applied early in life. For example, adopting a diet enriched in VitD, playing outdoor and avoiding passive smoking would be extremely simple measures of primary prevention for public health strategies. However, these hypotheses need to be confirmed by prospective evaluations, which are obviously difficult to conduct. In addition, it remains to be determined whether and how VitD supplementation in adult life would be useful in alleviating the course of MS, once this disease has already started. A better knowledge of the influence of various environmental stimuli on MS risk and course would certainly allow the development of add-on therapies or measures in parallel to the immunotherapies currently used in MS.

MRI-based diagnostic biomarkers for early onset pediatric multiple sclerosis

Currently, it is unclear whether pediatric multiple sclerosis (PMS) is a pathoetiologically homogeneous disease phenotype due to clinical and epidemiological differences between early and late onset PMS (EOPMS and LOPMS). Consequently, the question was raised whether diagnostic guidelines need to be complemented by specific EOPMS markers. To search for such markers, we analyzed cerebral MRI images acquired with standard protocols using computer-based classification techniques. Specifically, we applied classification algorithms to gray (GM) and white matter (WM) tissue probability parameters of small brain regions derived from T2-weighted MRI images of EOPMS patients (onset <12 years), LOPMS patients (onset ≥12 years), and healthy controls (HC). This was done for PMS subgroups matched for disease duration and participant age independently. As expected, maximal diagnostic information for distinguishing PMS patients and HC was found in a periventricular WM area containing lesions (87.1% accuracy, p < 2.2 × 10⁻⁵). MRI-based biomarkers specific for EOPMS were identified in prefrontal cortex. Specifically, a coordinate in middle frontal gyrus contained maximal diagnostic information (77.3%, p = 1.8 × 10⁻⁴). Taken together, we were able to identify biomarkers reflecting pathognomonic processes specific for MS patients with very early onset. Especially GM involvement in the separation between PMS subgroups suggests that conventional MRI contains a richer set of diagnostically informative features than previously assumed.

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EOPMS can be diagnosed accurately with computer-based classification and T2w-MRI.

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Separation of EOPMS and HC confirmed the pivotal role of WM lesions for diagnosis.

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Separation of EOPMS and LOPMS showed that GM variations are also informative.

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Thus, conventional MRI contains a richer set of biomarkers than assumed so far.

Balo concentric sclerosis in children: a case series

Baló concentric sclerosis is a unique and rare phenomenon in demyelinating disease. Typically thought of as a subtype of multiple sclerosis, Baló concentric sclerosis is characterized pathologically by striking rings of demyelination alternating with areas of preserved myelination. Its exact prevalence in adult and especially pediatric populations is unknown. Although traditionally considered to be an acute and fatal disease of adults, there are a handful of reports of Baló concentric sclerosis cases in pediatric patients. Here we report Baló concentric sclerosis-like demyelinating disease in 3 female pediatric patients, representing 2.2% of a cohort of 134 pediatric patients with demyelinating diseases who have been seen in our center since 2005. The relatively high prevalence of Baló concentric sclerosis-like cases in our pediatric demyelinating diseases center, none of which have been fatal, supports the premise that the developing immune and central nervous systems may manifest and respond to demyelinating disease differently from adults.

Astrocytes: the missing link in neurologic disease?

The central nervous system is comprised of numerous cell types that work in concert to facilitate proper function and homeostasis. Disruption of these carefully orchestrated networks results in neuronal dysfunction, manifesting itself in a variety of neurologic disorders. Although neuronal dysregulation is causative of symptoms that manifest in the clinic, the etiology of these disorders is often more complex than simply a loss of neurons or intrinsic dysregulation of their function. In the adult brain, astrocytes comprise the most abundant cell type and play key roles in central nervous system physiology; therefore, it stands to reason that dysregulation of normal astrocyte function contributes to the etiology and progression of varied neurologic disorders. We review here some neurologic disorders associated with an astrocyte factor and discuss how the related astrocyte dysfunction contributes to the etiology or progression of these disorders or both.

Increased Th17 response to myelin peptides in pediatric MS

Studies of the underlying immune mechanisms of multiple sclerosis (MS) in children may shed light on the initial events of MS pathogenesis. We studied T cell responses to myelin peptides in 10 pediatric MS patients (PMS), 10 pediatric healthy controls (PHC), 10 adult MS patients (AMS) and 10 adult healthy controls (AHC). A significantly higher proportion of divided CD4+ T cell responses in response to myelin peptides by the CFSE assay in PMS compared to PHC at both concentrations of myelin peptide tested (t test, 95% CI, p=0.0067 for MP1; p=0.0086 for MP10), and between PMS and AMS (p=0.0012 at 1 μg/mL of myelin peptides, p<0.0001 at 10 μg/mL) was found. In addition, T cells with a central memory phenotype producing IL-17 were increased in PMS compared to PHC (p<0.05). IL-7 levels in culture supernatants were elevated in PMS compared to PHC and AMS (t test<0.01).