Gender prevalence in childhood multiple sclerosis and myasthenia gravis

Paediatric myasthenia gravis: Prognostic factors for drug free remission

Our aim was to identify clinical outcomes, serological features and possible prognostic indicators of paediatric myasthenia gravis (MG). We collected 74 MG patients with disease onset before the age of 16 years (73% pre-pubertal onset defined as ≤10 years), seen regularly at two UK specialist centres, over a period of 11 years. The cohort was multi-ethnic, with a high number of non-Caucasians (52%). Ocular presentation was seen in 38 (51%) and only 8 (21%) of these generalised. Fifty-two (70%) patients had antibodies to the acetylcholine receptor (AChR) measured by radioimmunoprecipitation, 10 (14%) had antibodies only to clustered AChRs detected by a cell based assay, 3 (4%) had muscle-specific kinase and one (1%) low-density lipoprotein receptor-related protein 4 antibody. Only 8 (11%) had no detectable antibodies. Seventeen patients attained drug free remission (Kaplan Meyer survival curve estimates 25% by 7 years). Several factors were associated with a higher likelihood of free remission: onset age ≤10 years, Asian and Caucasian races, lack of AChR antibodies on RIA, and normal repetitive nerve stimulation at diagnosis. However, in a multifactorial regression analysis, the antibody status was the only significant predictor for drug free remission, with 60% of patients with antibodies only to clustered AChR achieving this outcome. Complete drug free remission is not uncommon in paediatric MG and several factors appear to influence this outcome with antibody status being the most important. These factors can be easily evaluated at diagnosis, and may help to determine whose patients are likely to require more intensive treatments.

Generalized Myasthenia Gravis: Classification, Clinical Presentation, Natural History, and Epidemiology

Myasthenia gravis (MG) is a rare disease, but the most common disorder of the neuromuscular junction. It is the prototypic autoimmune disease most commonly caused by antibodies to the acetylcholine receptor (AChR) leading to characteristic fatigable weakness of the ocular, bulbar, respiratory, axial, and limb muscles. The majority of patients with MG first present with ocular symptoms. Most patients with MG will experience at least 1 exacerbation of symptoms throughout the course of their illness. This article will cover the epidemiology, clinical presentation, classification, and natural history of MG.

Clinical Characteristics of Juvenile Myasthenia Gravis in Southern China

Objectives

To describe the clinical profile, clinical outcomes and factors that may affect the outcome of juvenile myasthenia gravis (JMG) patients in southern China.

Methods

We reviewed information relating to JMG patients treated and evaluated at the First Affiliated Hospital, Sun Yat-sen University, between 1998 and 2015. The study involved 327 JMG patients who had been followed up for ≥1 year.

Results

Overall, 77.4% patients showed initial symptoms in the prepubertal period (<12 years). 306 patients showed only ocular symptoms at onset. By the final follow-up, 61 ocular myasthenia gravis (OMG) patients (61/306, 19.9%) had developed generalized myasthenia gravis (GMG). Anti-acetylcholine receptor antibodies (AChR-Ab) titer was an independent risk factor for generalization. Eleven patients (3.4%) experienced spontaneous remission, but four relapsed. Low-dose oral prednisone (0.25 mg/kg) was administered when symptoms did not significantly improve after pyridostigmine treatment. Immunosuppressants were administered when prednisone was unsatisfactory. Optimal outcome was achieved in 59.6% of patients. Specifically, 60 patients (18.3%) attained complete stable remission (CSR), 12 (3.7%) attained pharmaceutical remission (PR), and 123 (37.6%) attained minimal manifestation (MM). In total, 53 OMG patients (21.5%) attained CSR, a significantly higher proportion than among the GMG patients (8.6%, P = 0.009). Moreover, 67.2% of patients with duration <2 years showed significant clinical improvement compared with 46.3% of those with duration >2 years (P < 0.001). Thymectomy did not exhibit definite efficacy for JMG patients.

Conclusion

There was a low frequency of cases positive for AChR-Ab in the Chinese population. AChR-Ab titer was revealed as an independent risk factor for generalization. Low doses of prednisone could treat JMG effectively with few side effects.

Long-term follow-up of pediatric MS patients starting treatment with injectable first-line agents: A multicentre, Italian, retrospective, observational study

Background:

Few data are available on very long-term follow-up of pediatric multiple sclerosis (MS) patients treated with disease modifying treatments (DMTs).

Objectives:

To present a long-term follow-up of a cohort of Pediatric-MS patients starting injectable first-line agents.

Methods:

Data regarding treatments, annualized relapse rate (ARR), Expanded Disability Status Scale (EDSS) score, and serious adverse event were collected. Baseline characteristics were tested in multivariate analysis to identify predictors of disease evolution.

Results:

In total, 97 patients were followed for 12.5 ± 3.3 years. They started therapy at 13.9 ± 2.1 years, 88 with interferons and 9 with copaxone. During the whole follow-up, 82 patients changed therapy, switching to immunosuppressors/second-line treatment in 58% of cases. Compared to pre-treatment phase, the ARR was significantly reduced during the first treatment (from 3.2 ± 2.6 to 0.7 ± 1.5, p < 0.001), and it remained low during the whole follow-up (0.3 ± 0.2, p < 0.001). At last observation, 40% had disability worsening, but EDSS score remained <4 in 89%. One patient died at age of 23 years due to MS. One case of natalizumab-related progressive multifocal encephalopathy (PML) was recorded. Starting therapy before 12 years of age resulted in a better course of disease in multivariate analysis.

Conclusion:

Pediatric-MS patients benefited from interferons/copaxone, but the majority had to switch to more powerful drugs. Starting therapy before 12 years of age could lead to a more favorable outcome.

Characteristics of pediatric multiple sclerosis: The Turkish pediatric multiple sclerosis database

OBJECTIVE

To document the clinical and paraclinical features of pediatric multiple sclerosis (MS) in Turkey.

METHODS

Data of MS patients with onset before age 18 years (n = 193) were collected from 27 pediatric neurology centers throughout Turkey. Earlier-onset (<12 years) and later-onset (≥12 years) groups were compared.

RESULTS

There were 123 (63.7%) girls and 70 (36.3%) boys aged 4-17 years, median 14 years at disease onset. Family history of MS was 6.5%. The first presentation was polysymptomatic in 55.4% of patients, with brainstem syndromes (50.3%), sensory disturbances (44%), motor symptoms (33.2%), and optic neuritis (26.4%) as common initial manifestations. Nineteen children had facial paralysis and 10 had epileptic seizures at first attack; 21 (11%) were initially diagnosed with acute disseminated encephalomyelitis (ADEM). Oligoclonal bands were identified in 68% of patients. Magnetic resonance imaging revealed periventricular (96%), cortical/juxtacortical (64.2%), brainstem (63%), cerebellum (51.4%), and spinal cord (67%) involvement. Visual evoked potentials (VEP) were abnormal in 52%; serum 25-hydroxyvitamin D levels were low in 68.5% of patients. The earlier-onset group had a higher rate of infection/vaccination preceding initial attack, initial diagnosis of ADEM, longer interval between first 2 attacks, and more disability accumulating in the first 3 years of the disease.

CONCLUSION

Brainstem and cerebellum are common sites of clinical and radiological involvement in pediatric-onset MS. VEP abnormalities are frequent even in patients without history of optic neuropathy. Vitamin D status does not appear to affect the course in early disease. MS beginning before 12 years of age has certain characteristics in history and course.

Clinical features and evolution of juvenile myasthenia gravis in a French cohort

INTRODUCTION

In this study we determined the clinical, paraclinical, and treatment-related features of juvenile myasthenia gravis (JMG) as well as the clinical course in a cohort of French children.

METHODS

We conducted a retrospective study of 40 patients with JMG at 2 French pediatric neurology departments from April 2004 to April 2014.

RESULTS

Among the patients, 70% had generalized JMG, 52% had positive acetylcholine receptor antibodies, 8% had muscle-specific kinase antibodies, and 40% were seronegative. Treatment with acetylcholinesterase inhibitors was effective and sufficient in 47% of patients. The 6 patients with generalized JMG treated with rituximab and/or immunoadsorption showed improvement. Thirty percent of the patients required hospitalization in an intensive care unit during follow-up (mean 4.7 years). Remission without treatment occurred in 18% of patients.

DISCUSSION

As with adults, JMG has high morbidity, particularly among children with generalized symptoms, and rituximab should be considered early in the course of the disease as a second-line treatment. Muscle Nerve 57: 603-609, 2018.

Juvenile myasthenia gravis in Norway: A nationwide epidemiological study

BACKGROUND

The aim of this study was to assess the incidence rate and prevalence of autoimmune myasthenia gravis (MG) among children in Norway.

METHODS

This retrospective population-based study was performed in Norway from January 2012 to December 2013. Cases of juvenile MG (JMG) with onset < 18 years were identified through searches in coding systems of electronic patient records at the 15 main hospitals in Norway from 1989 to 2013. In addition, the acetylcholine receptor antibody database at Haukeland University Hospital and the clinical nationwide MG database at Oslo University Hospital were searched for cases of JMG. Diagnosis and age at onset were verified through medical records. Incidence and prevalence rates were calculated using the Norwegian population as reference.

RESULTS

In total 63 unique JMG cases were identified. This corresponds to an average annual incidence rate of 1.6 per million. Incidence rate was stable over the study period. Prevalence of JMG was 3.6-13.8 per million. Females constituted the majority of JMG cases (55 vs 8 males). The risk of JMG was higher among females both in the postpubertal and prepubertal group (p < 0.001 and p = 0.02, respectively).

CONCLUSION

This study confirms the rarity of JMG in Norway, especially among males, and shows a stable incidence rate over the last 25 years.

Paediatric clinically isolated syndromes: report of seven cases, differential diagnosis and literature review

PURPOSE

Few paediatric cases of clinically isolated syndrome (CIS) have been described in literature, even though it has been increasingly recognized also in this age group. Our study retrospectively enrolled seven Italian patients (four males and three females) who met the International Paediatric Multiple Sclerosis Study Group (IPMSSG) 2012 criteria for clinically isolated syndrome over the period 2010-2014; their clinical, laboratory and imaging findings were compared with current literature and with those seen in five patients (three males and two females) with acute disseminated encephalomyelitis, who were followed in our department over the same years (mean follow-up time 2.84 ± 1.8 years).

RESULTS

In our CIS sample, male sex was prevalent, 42.8 % of patients had a multifocal presentation, MRI lesions mostly appeared confluent and with poorly defined margins, and CSF oligoclonal bands (OCBs) were identified in 28.6 %. All acute disseminated encephalomyelitis (ADEM) patients had polyfocal presentation and encephalopathy; large MRI subcortical lesions and polyclonal IgG distribution were identified. During the subsequent follow-up assessments, MRI scan revealed new lesions in three CIS patients, while in ADEM children it appeared normal.

CONCLUSIONS

Paediatric CIS patients often show peculiar epidemiological, clinical and radiological features, which significantly differ from adult ones. The presence of encephalopathy and of extended MRI lesions leads to a diagnosis of ADEM, instead. In CIS patients the presence of multiple asymptomatic MRI lesions and of OCBs revealed to be the most predictive risk factors for progression to clinically definite multiple sclerosis (CDMS), so a regular long-term follow-up is recommended; in ADEM, no suitable risk factors for a relapse could be identified.

An increase in circulating B cell-activating factor in childhood-onset ocular myasthenia gravis

BACKGROUND

Myasthenia gravis is a B cell-mediated autoimmune disorder. The pathophysiology of childhood-onset ocular myasthenia gravis remains unclear. We investigated serum B cell-activating factor levels and other immunological parameters in child patients with ocular myasthenia gravis.

METHODS

Blood samples were obtained from 9 children with ocular myasthenia gravis and 20 age-matched controls. We assayed serum concentrations of B cell-activating factor, anti-acetylcholine receptor antibody titers, 7 types of cytokines (interleukins-2, -4, -6, -10, and -17A; interferon-γ; tumor necrosis factor-α) as well as the percentages of peripheral blood CD4+, CD8+, and CD19+ cells.

RESULTS

Serum B cell-activating factor levels were significantly higher before immunosuppressive therapy in patients with childhood-onset ocular myasthenia gravis than in controls and decreased after immunosuppressive therapy. A significant positive correlation was observed between serum B cell-activating factor levels and anti-acetylcholine receptor antibody titers in patients with myasthenia gravis. Serum B cell-activating factor concentrations did not correlate with the percentages of CD4+, CD8+, and CD19+ cells or the CD4+/CD8+ ratio. No significant differences were observed in the levels of the 7 different types of cytokines examined, including interleukin-17A, between preimmunosuppressive therapy myasthenia gravis patients and controls.

CONCLUSIONS

Circulating B cell-activating factor may play a key role in the pathophysiology of childhood-onset ocular myasthenia gravis.

How common is childhood myasthenia? The UK incidence and prevalence of autoimmune and congenital myasthenia

OBJECTIVE

To ascertain the frequency of childhood myasthenia in the UK. Specifically, we aimed to identify the detected incidence of autoimmune myasthenia and the detected prevalence of genetically confirmed congenital myasthenic syndrome (CMS) in children.

METHODS

All children under 18 years of age on 31 December 2009 with a confirmed CMS genetic mutation were identified by the only UK laboratory undertaking CMS genetic testing. All cases with positive acetylcholine receptor (AChR) and muscle specific kinase (MuSK) receptor antibodies in the 5 years between 2003 and 2007 inclusive were identified by the testing laboratories. UK census data from 2001 were used as the denominator for analyses.

RESULTS

The UK detected prevalence of genetically confirmed CMS was 9.2 per million children under 18 years of age. CMS was equally prevalent in girls and boys. CHRNE, RAPSN and DOK7 were the most commonly identified mutations. Prevalence varied across geographical regions in England (between 2.8 and 14.8 per million children). The mean incidence of antibody-positive autoimmune myasthenia was 1.5 per million children per year over the period of the study. Girls were affected more frequently than boys; this difference persisted across the age range. Antibodies were identified during the neonatal period in 17 children.

CONCLUSIONS

This laboratory based study shows that childhood myasthenia is very rare. This condition is treatable, and these definitive detected incidence and prevalence data can be used to help plan diagnostic and supporting services for affected children and their families, and maximise research opportunities.

Multiple sclerosis in children

The onset of multiple sclerosis (MS) in childhood and adolescence is being increasingly recognized. Relative to MS in adults, little is known about the diagnostic evaluation, clinical course, outcome, and management of MS in children. To remedy some of these deficiencies, pediatric MS clinics have been created in several countries to provide specialized care to, and to study, affected children. Research is currently underway to investigate the pathobiologic features of childhood-onset MS, to study the mechanisms of myelin inflammation and repair, to evaluate patient outcomes collaboratively between the different clinics, and to increase knowledge of pediatric MS for children living with the disease. It is hoped that, through an understanding of the earliest aspects of the MS disease process, critical insights will be gained about the genesis of MS.

Juvenile myasthenia gravis: a twenty-year experience

OBJECTIVE

Juvenile myasthenia gravis (JMG) is an antibody-mediated autoimmune disorder of the neuromuscular junction, at the postsynaptic end plate. JMG presents with fluctuating skeletal muscle weakness and fatigue before the age of 18 years. Very frequently JMG presents with the involvement of the oculomotor muscles, with or without generalized involvement.

METHODS

We performed a retrospective chart review of patients diagnosed with myasthenia in the pediatric neuromuscular clinics at UT Southwestern, between 1990 and 2010. Osserman classification and the response to therapy scale of Millichap and Dodge were used to compare each patient's severity of myasthenia and responsiveness to drugs before the surgery as a baseline and at the last visit, after thymectomy.

RESULTS

Fifty-eight patients were included; 29 (50%) were African American, and 34 (58.6%) were female. Age of onset was 11 months to 17 years, and 38 patients (65%) presented as generalized myasthenia gravis. Forty-nine patients (84%) were acetylcholine receptor antibody (AchR-Ab) positive. Of the 32 to undergo thymectomy, 19 subjects (59%) experienced an improved response to B level on the Myasthenia Scale of Millichap and Dodge (good improvement, both objective and subjective, but continuation of drug therapy required in the same or lower dosage) and 75% experienced a drop in Osserman classification by at least 1. Of the 8 individuals who did not show improvement after thymectomy, 4 subjects (50%) underwent repeat thymectomy. They had initially less invasive fluoroscopic or thoracoscopic procedure. Thymic hyperplasia was found in 7 patients (21%) and thymoma in 2.

CONCLUSIONS

Thymectomy was well tolerated by this group of children. There was clinical improvement after thymectomy in two thirds of the AchR-Ab-positive generalized myasthenia gravis patients. Thymic pathology was seen in less than one third of the patients who underwent thymectomy, with thymic hyperplasia being common. Further studies are necessary to determine whether thymectomy is indicated for all children with generalized JMG. More information about the immunologic, genetic, and molecular differences between patients may determine the best treatment for individual patients.

Male gender bias in autism and pediatric autoimmunity

Male bias in both autism and pediatric autoimmune disease is thought to involve hormonal perturbations in pregnancy or early childhood in the context of genetic control. These early molecular events, at a time of rapid development, are intimately linked to concurrent development in the brain and immune system. It is suggested here that these early regulatory events may overlap between autism and autoimmunity in determining male sex bias and may provide evidence of an etiological link among autism, immune dysregulation, and autoimmune disease.

Juvenile myasthenia gravis: a paediatric perspective

Myasthenia gravis (MG) is an autoimmune disease in which antibodies are directed against the postsynaptic membrane of the neuromuscular junction, resulting in muscle weakness and fatigability. Juvenile myasthenia gravis (JMG) is a rare condition of childhood and has many clinical features that are distinct from adult MG. Prepubertal children in particular have a higher prevalence of isolated ocular symptoms, lower frequency of acetylcholine receptor antibodies, and a higher probability of achieving remission. Diagnosis in young children can be complicated by the need to differentiate from congenital myasthenic syndromes, which do not have an autoimmune basis. Treatment commonly includes anticholinesterases, corticosteroids with or without steroid-sparing agents, and newer immune modulating agents. Plasma exchange and intravenous immunoglobulin (IVIG) are effective in preparation for surgery and in treatment of myasthenic crisis. Thymectomy increases remission rates. Diagnosis and management of children with JMG should take account of their developmental needs, natural history of the condition, and side-effect profiles of treatment options.

Pediatric multiple sclerosis

BACKGROUND

Pediatric multiple sclerosis (MS), once considered a rare childhood illness, has been increasingly identified as an important childhood acquired neurologic disease requiring early recognition and intervention.

SUMMARY

We present a comprehensive review of the current terminology of acquired central nervous system demyelination in children, pertinent investigations, including magnetic resonance imaging and cerebrospinal fluid cerebrospinal fluid studies, and an approach to the differential diagnosis of pediatric onset MS. In addition, the recent studies exploring the epidemiology and pathobiology will be discussed. Finally, we present an algorithm for the treatment of episodes of demyelination along with chronic immunomodulatory therapeutic options in this patient population.

CONCLUSIONS

Although some similarities exist to adult onset MS, MS onset during childhood and adolescence presents unique diagnostic challenges and requires specialized multidisciplinary care for optimal management. National and international collaborative studies are underway to aid in the understanding of the early and ongoing pathogenesis of MS.

Magnetic resonance imaging at first episode in pediatric multiple sclerosis retrospective evaluation according to KIDMUS and lesion dissemination in space criteria

BACKGROUND

Several diagnostic imaging criteria are being described and examined in pediatric multiple sclerosis (MS). Compared to adults, children are more likely to experience acute or relapsing demyelinating episodes of various etiologies which show similar clinical and magnetic resonance imaging (MRI) findings.

AIM

To investigate the fulfillment of MRI diagnostic criteria at initial episode in pediatric MS.

METHODS

We reviewed our series of children and adolescents with the final diagnosis of clinically definite MS and applied the McDonald dissemination in space (DIS) and KIDMUS criteria to their initial MRI scans.

RESULTS

Thirty patients (17 girls, 13 boys), most with brainstem dysfunction and polysymptomatic presentation, were included in the study. Twenty-five (83.3%) patients fulfilled both McDonald and KIDMUS criteria. Patients who did not meet any McDonald DIS criteria did not meet KIDMUS criteria either. Only one patient met the McDonald criteria but not the KIDMUS criteria because of the absence of lesions perpendicular to corpus callosum.

CONCLUSIONS

Our results show 5/30 (16.6%) of MS patients may not present the diagnostic MRI features initially. The variable sensitivity observed for the current MRI criteria in different series can be due to referral biases, differences between populations and length of follow-up, and the definition of MS patients by two attacks only.

Autism, asthma, inflammation, and the hygiene hypothesis

Inflammation and the genes, molecules, and biological pathways that lead to inflammatory processes influence many important and disparate biological processes and disease states that are quite often not generally considered classical inflammatory or autoimmune disorders. These include development, reproduction, aging, tumor development and tumor rejection, cardiovascular pathologies, metabolic disorders, as well as neurological and psychiatric disorders. This paper compares parallel aspects of autism and inflammatory disorders with an emphasis on asthma. These comparisons include epidemiological, morphometric, molecular, and genetic aspects of both disease types, contributing to a hypothesis of autism in the context of the immune based hygiene hypothesis. This hypothesis is meant to address the apparent rise in the prevalence of autism in the population.