Daniela Pohl

International Pediatric Multiple Sclerosis Study Group criteria for pediatric multiple sclerosis and immune-mediated central nervous system demyelinating disorders: revisions to the 2007 definitions.

Background: There has been tremendous growth in research in pediatric multiple sclerosis (MS) and immune mediated central nervous system demyelinating disorders since operational definitions for these conditions were first proposed in 2007. Further, the International Pediatric Multiple Sclerosis Study Group (IPMSSG), which proposed the criteria, has expanded substantially in membership and in its international scope. Objective: The purpose of this review is to revise the 2007 definitions in order to incorporate advances in delineating the clinical and neuroradiologic features of these disorders. Methods: Through a consensus process, in which input was sought from the 150 members of the Study Group, criteria were drafted, revised and finalized. Final approval was sought through a web survey. Results: Revised criteria are proposed for pediatric acute disseminated encephalomyelitis, pediatric clinically isolated syndrome, pediatric neuromyelitis optica and pediatric MS. These criteria were approved by 93% or more of the 56 Study Group members who responded to the final survey. Conclusions: These definitions are proposed for clinical and research purposes. Their utility will depend on the outcomes of their application in prospective research.

Self-antigen tetramers discriminate between myelin autoantibodies to native or denatured protein

The role of autoantibodies in the pathogenesis of multiple sclerosis (MS) and other demyelinating diseases is controversial, in part because widely used western blotting and ELISA methods either do not permit the detection of conformation-sensitive antibodies or do not distinguish them from conformation-independent antibodies. We developed a sensitive assay based on self-assembling radiolabeled tetramers that allows discrimination of antibodies against folded or denatured myelin oligodendrocyte glycoprotein (MOG) by selective unfolding of the antigen domain. The tetramer radioimmunoassay (RIA) was more sensitive for MOG autoantibody detection than other methodologies, including monomer-based RIA, ELISA or fluorescent-activated cell sorting (FACS). Autoantibodies from individuals with acute disseminated encephalomyelitis (ADEM) selectively bound the folded MOG tetramer, whereas sera from mice with experimental autoimmune encephalomyelitis induced with MOG peptide immunoprecipitated only the unfolded tetramer. MOG-specific autoantibodies were identified in a subset of ADEM but only rarely in adult-onset MS cases, indicating that MOG is a more prominent target antigen in ADEM than MS.

Clinical, environmental, and genetic determinants of multiple sclerosis in children with acute demyelination: a prospective national cohort study

BACKGROUND HLA-DRB1*15 genotype, previous infection with Epstein-Barr virus, and vitamin D insufficiency are susceptibility factors for multiple sclerosis, but whether they act synergistically to increase risk is unknown. We aimed to assess the contributions of these risk factors and the effect of established precursors of multiple sclerosis, such as brain lesions on MRI and oligoclonal bands in CSF at the time of incident demyelination, on development of multiple sclerosis in children. METHODS In our prospective national cohort study, we assessed children who presented with incident CNS demyelination to any of the 16 paediatric health-care facilities or seven regional health-care facilities in Canada. We did univariate and multivariable analyses to assess contributions of HLA-DRB1*15, Epstein-Barr virus, vitamin D status, MRI evidence of brain lesions, and CSF oligoclonal bands as determinants of multiple sclerosis. We used classification and regression tree analyses to generate a risk stratification algorithm for clinical use. FINDINGS Between Sept 1, 2004, and June 30, 2010, we screened 332 children of whom 302 (91%) were eligible and followed-up for a median of 3·14 years (IQR 1·61-4·51). 63 (21%) children were diagnosed with multiple sclerosis after a median of 127 days (99-222). Although the risk of multiple sclerosis was increased with presence of one or more HLA-DRB1*15 alleles (hazard ratio [HR] 2·32, 95% CI 1·25-4·30), reduced serum 25-hydroxyvitamin D concentration (HR per 10 nmol/L decrease 1·11, 1·00-1·25), and previous Epstein-Barr-virus infection (HR 2·04, 0·99-4·20), no interactions between these variables were detected on multivariate analysis. Multiple sclerosis was strongly associated with baseline MRI evidence of one or more brain lesion (HR 37·9, 5·26-273·85) or CSF oligoclonal bands (6·33, 3·35-11·96), suggesting established disease. One patient diagnosed with multiple sclerosis had a normal MRI scan, and therefore sensitivity of an abnormal MRI scan for multiple sclerosis diagnosis was 98·4%. INTERPRETATION Risk of multiple sclerosis in children can be stratified by presence of HLA-DRB1*15 alleles, remote Epstein-Barr virus infection, and low serum 25-hydroxyvitamin D concentrations. Similar to previous studies in adults, brain lesions detected on MRI and CSF oligoclonal bands in children are probable precursors to the clinical onset of multiple sclerosis. Children with a normal MRI are very likely to have a monophasic illness. FUNDING Canadian Multiple Sclerosis Scientific Research Foundation.

Antibodies to MOG are transient in childhood acute disseminated encephalomyelitis

Objective: To study the longitudinal dynamics of anti–myelin oligodendrocyte glycoprotein (MOG) autoantibodies in childhood demyelinating diseases. Methods: We addressed the kinetics of anti-MOG immunoglobulins in a prospective study comprising 77 pediatric patients. This was supplemented by a cross-sectional study analyzing 126 pediatric patients with acute demyelination and 62 adult patients with multiple sclerosis (MS). MOG-transfected cells were used for detection of antibodies by flow cytometry. Results: Twenty-five children who were anti-MOG immunoglobulin (Ig) positive at disease onset were followed for up to 5 years. Anti-MOG antibodies rapidly and continuously declined in all 16 monophasic patients with acute disseminated encephalomyelitis and in one patient with clinically isolated syndrome. In contrast, in 6 of 8 patients (75%) eventually diagnosed with childhood MS, the antibodies to MOG persisted with fluctuations showing a second increase during an observation period of up to 5 years. Antibodies to MOG were mainly IgG 1 and their binding was largely blocked by pathogenic anti-MOG antibodies derived from a spontaneous animal model of autoimmune encephalitis. The cross-sectional part of our study elaborated that anti-MOG Ig was present in about 25% of children with acute demyelination, but in none of the pediatric or adult controls. Sera from 4/62 (6%) adult patients with MS had anti-MOG IgG at low levels. Conclusions: The persistence or disappearance of antibodies to MOG may have prognostic relevance for acute childhood demyelination.

High seroprevalence of Epstein–Barr virus in children with multiple sclerosis

We studied seroprevalence and concentrations of Epstein–Barr virus (EBV) antibodies in 147 pediatric patients with multiple sclerosis (MS) and paired controls. The children with MS showed a near-complete seropositivity for EBV antibody against virus capsid antigen (98.6% vs 72.1% in controls, p = 0.001) but did not display serologic evidence for a recent EBV infection. EBV antibody concentrations of pediatric patients with MS were significantly higher vs controls.

Age-Dependent B Cell Autoimmunity to a Myelin Surface Antigen in Pediatric Multiple Sclerosis

Multiple sclerosis (MS) typically manifests in early to mid adulthood, but there is increasing recognition of pediatric-onset MS, aided by improvements in imaging techniques. The immunological mechanisms of disease are largely unexplored in pediatric-onset MS, in part because studies have historically focused on adult-onset disease. We investigated autoantibodies to myelin surface Ags in a large cohort of pediatric MS cases by flow cytometric labeling of transfectants that expressed different myelin proteins. Although Abs to native myelin oligodendrocyte glycoprotein (MOG) were uncommon among adult-onset patients, a subset of pediatric patients had serum Abs that brightly labeled the MOG transfectant. Abs to two other myelin surface Ags were largely absent. Affinity purification of MOG Abs as well as competition of binding with soluble MOG documented their binding specificity. Such affinity purified Abs labeled myelin and glial cells in human CNS white matter as well as myelinated axons in gray matter. The prevalence of such autoantibodies was highest among patients with a very early onset of MS: 38.7% of patients less than 10 years of age at disease onset had MOG Abs, compared with 14.7% of patients in the 10- to 18-year age group. B cell autoimmunity to this myelin surface Ag is therefore most common in patients with a very early onset of MS.

Safety and tolerability of interferon beta-1b in pediatric multiple sclerosis.

Background: Immunomodulatory therapies are widely used in adults with multiple sclerosis (MS) and safety and tolerability is well-established. Although at least 5% of all patients with MS experience the clinical onset of their disease prior to age 18 years, the available literature on safety and tolerability of immunomodulatory therapies for pediatric-onset MS is limited. Methods: The authors retrospectively reviewed safety and tolerability of interferon beta-1b (IFNβ-1b) in a cohort of 43 children and adolescents treated for a mean of 29.2 months (SD 22.3 months). Results: Mean age at start of IFNβ-1b treatment was 13 years. Eight children were ≤10 years. Most common adverse events included flu-like syndrome (35%), abnormal liver function test (26%), and injection site reaction (21%). No serious or unexpected adverse events were reported. Conclusions: Although data on long-term effects on the maturing organ systems are lacking, the safety profile supports the safety and tolerability of interferon beta-1b (IFNβ-1b) in children with multiple sclerosis and related diseases. All patients treated with IFNβ-1b should undergo regular monitoring of liver function.

Consensus statement: evaluation of new and existing therapeutics for pediatric multiple sclerosis

New therapies are being evaluated by clinical trials and, if efficacious, introduced for the treatment of adult MS. The role of these new and existing agents in the management of pediatric MS has yet to be defined. Pediatric investigation plans are now required by the Food and Drug Administration and European Medicines Agency for approval of new biological agents, providing an important opportunity to gather much-needed data for clinicians caring for children and adolescents with MS. However, challenges include the small number of patients, and the need for efficient yet comprehensive study designs incorporating factors necessary to inform the clinical care of children with MS. The elected Steering committee of the International Pediatric MS Study Group (IPMSSG) conducted a structured review of existing data on the disease-modifying therapies in pediatric MS and developed a consensus statement, which was further modified by the IPMSSG general membership, using an online survey tool. Fifty-one IPMSSG members from 21 countries responded to the survey, and 50 approved the final statement. Consensus recommendations regarding use of existing first- and second-line therapies, as well as a proposed definition for inadequate treatment response, are presented. Recommendations for the use and evaluation of emerging therapies (currently in phase III clinical trials or recently approved for adult MS) are discussed. The IPMSSG endorses the inclusion of pediatric MS patients in trials evaluating appropriate new and emerging therapies. Mechanisms for conducting high-impact, multicenter studies, including long-term follow-up in pediatric MS, are required to ensure that all MS patients, irrespective of age, benefit from advances in MS therapeutics.

CSF characteristics in early-onset multiple sclerosis.

The authors studied CSF characteristics in 136 patients with multiple sclerosis (MS) with a disease onset before age 16. In the initial diagnostic lumbar puncture, CSF-pleocytosis was observed in 66%, blood–CSF barrier dysfunction in 13%, and oligoclonal IgG in 92% of the early-onset MS (EOMS) patients. CSF oligoclonal IgG supports the early diagnosis of MS in childhood with a sensitivity similar to adult-onset MS.

Treatment of early onset multiple sclerosis with subcutaneous interferon beta-1a

The authors studied the tolerability of subcutaneous interferon beta-1a (IFNβ-1a) in 51 patients with early-onset multiple sclerosis. The most frequent systemic adverse effects were flu-like symptoms in 65%. Laboratory abnormalities included asymptomatic leukopenia (27%) and elevated hepatic transaminases (35%). Treatment with IFNβ-1a was safe and well tolerated in the majority of children and adolescents.