Barbara Kornek

Multiple Sclerosis and Chronic Autoimmune Encephalomyelitis : A Comparative Quantitative Study of Axonal Injury in Active, Inactive, and Remyelinated Lesions

Recent magnetic resonance (MR) studies of multiple sclerosis lesions indicate that axonal injury is a major correlate of permanent clinical deficit. In the present study we systematically quantified acute axonal injury, defined by immunoreactivity for beta-amyloid-precursor-protein in dystrophic neurites, in the central nervous system of 22 multiple sclerosis patients and 18 rats with myelin-oligodendrocyte glycoprotein (MOG)-induced chronic autoimmune encephalomyelitis (EAE). The highest incidence of acute axonal injury was found during active demyelination, which was associated with axonal damage in periplaque and in the normal appearing white matter of actively demyelinating cases. In addition, low but significant axonal injury was also observed in inactive demyelinated plaques. In contrast, no significant axonal damage was found in remyelinated shadow plaques. The patterns of axonal pathology in chronic active EAE were qualitatively and quantitatively similar to those found in multiple sclerosis. Our studies confirm previous observations of axonal destruction in multiple sclerosis lesions during active demyelination, but also indicate that ongoing axonal damage in inactive lesions may significantly contribute to the clinical progression of the disease. The results further emphasize that MOG-induced EAE may serve as a suitable model for testing axon-protective therapies in inflammatory demyelinating conditions.

Axonal pathology in multiple sclerosis. A historical note.

Recently, the detection of axonal degeneration in the lesions of multiple sclerosis has attracted new and unexpected attention (24, 57). Magnetic resonance techniques such as MR-spectroscopy (3, 17, 20, 29, 42) and magnetization transfer imaging (25, 31, 37, 59) have provided insight into the pathophysiologic changes in multiple sclerosis, suggesting more pronounced damage to axons than had been previously assumed (6, 60-61). Moreover, the correlation found between axonal damage and clinical disability (6, 16, 36, 39) has stimulated a revival of axonal pathology research, which has found its preliminary climax in the description of “Axonal transections in the lesions of multiple sclerosis” by Trapp et al. (57). Review of early literature suggests that axonal damage, including axonal pathologic changes such as axonal swellings (2, 7-10, 15, 21-23, 28, 30, 35, 41, 50) and transections (2, 22, 28, 35, 46), had already been recognized and described in detail at the turn of the century (Figure 1). At the time of their publication, the first descriptions of axonal pathology in MS were an intensely discussed and controversial subject (9, 10, 13, 52, 55).

Neuropathology of multiple sclerosis—new concepts

Multiple sclerosis lesions are characterized by inflammation, demyelination and a variable degree of axonal loss. The patterns of inflammation in MS lesions are compatible with a T-lymphocyte mediated immune reaction. The formation of demyelinated plaques, however, seem to require additional immunological mechanisms. In this review evidence is discussed for a pathogenetic role of demyelinating antibodies, toxic macrophage products, cytotoxic T-cells as well as metabolic disturbances of oligodendrocytes. It is suggested that the pathological heterogeneity regarding the patterns and extent of demyelination, remyelination and axonal loss may be the outcome of variable dominant immunopathogenetic mechanisms in different multiple sclerosis patients.

The management of multiple sclerosis in children: a European view

About 3—5% of all patients with multiple sclerosis experience the onset of their disease under the age of 16. A significant proportion of paediatric multiple sclerosis patients develop significant cognitive disturbances and persistent physical disability. The high relapse rate and the morbidity in the paediatric multiple sclerosis population has triggered the use of disease-modifying therapies that have been shown to reduce relapse rate, disease progression and cognitive decline in adult patients with multiple sclerosis. Hard evidence for the right treatment and its appropriate timing is scarce in paediatric multiple sclerosis. Nevertheless, expertise in this field has grown thanks to recent open-label trials and experience generated in specialized centres. In spring 2009, a first meeting was held in Rotterdam with clinicians from 11 European countries (one from Canada) that are all active in the management of paediatric multiple sclerosis. One of the aims was to generate a common view on the management of paediatric multiple sclerosis patients. The result of this meeting is presented here to help standardize treatment and to support clinicians with less experience in this field.

New Loci Regulating Rat Myelin Oligodendrocyte Glycoprotein-Induced Experimental Autoimmune Encephalomyelitis

Myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis (EAE) is an inflammatory disease in rats that closely mimics many clinical and histopathological aspects of multiple sclerosis. Non-MHC quantitative trait loci regulating myelin oligodendrocyte glycoprotein-induced EAE have previously been identified in the EAE-permissive strain, DA, on rat chromosomes 4, 10, 15, and 18. To find any additional gene loci in another well-known EAE-permissive strain and thereby to assess any genetic heterogeneity in the regulation of the disease, we have performed a genome-wide linkage analysis in a reciprocal (LEW.1AV1 × PVG.1AV1) male/female F2 population (n = 185). We examined reciprocal crosses, but no parent-of-origin effect was detected. The parental rat strains share the RT1av1 MHC haplotype; thus, non-MHC genes control differences in EAE susceptibility. We identified Eae16 on chromosome 8 and Eae17 on chromosome 13, significantly linked to EAE phenotypes. Two loci, on chromosomes 1 and 17, respectively showed suggestive linkage to clinical and histopathological EAE phenotypes. Eae16 and Eae17 differ from those found in previously studied strain combinations, thus demonstrating genetic heterogeneity of EAE. Furthermore, we detected a locus-specific parent-of-origin effect with suggestive linkage in Eae17. Further genetic and functional dissection of these loci may disclose critical disease-regulating molecular mechanisms.

Children with multiphasic disseminated encephalomyelitis and antibodies to the myelin oligodendrocyte glycoprotein (MOG): Extending the spectrum of MOG antibody positive diseases

Background: Myelin oligodendrocyte glycoprotein (MOG) antibodies have been described in children with acute disseminated encephalomyelitis (ADEM), recurrent optic neuritis, neuromyelitis optica spectrum disorders and more recently in children with multiphasic disseminated encephalomyelitis (MDEM). Objective: To delineate the clinical, cerebrospinal fluid (CSF) and radiological features of paediatric MDEM with MOG antibodies. Methods: Clinical course, serum antibodies, CSF, magnetic resonance imaging (MRI) studies and outcome of paediatric MDEM patients were reviewed. Results: A total of 8 children with two or more episodes of ADEM were identified from a cohort of 295 children with acute demyelinating events. All children had persisting MOG antibodies (median titre: 1:1280). All ADEM episodes included encephalopathy, polyfocal neurological signs and a typical MRI. Apart from ADEM episodes, three children had further clinical attacks without encephalopathy. Median age at initial presentation was 3 years (range: 1–7 years) and median follow-up 4 years (range: 1–8 years). New ADEM episodes were associated with new neurological signs and new MRI lesions. Clinical outcome did range from normal (four of the eight) to mild or moderate impairment (four of the eight). A total of four children received monthly immunoglobulin treatment during the disease course. Conclusion: Children with MDEM and persisting MOG antibodies constitute a distinct entity of relapsing demyelinating events and extend the spectrum of MOG antibody–associated diseases.

Natalizumab Therapy for Highly Active Pediatric Multiple Sclerosis

IMPORTANCE Given the high frequency of failure of first-line therapies, there is an urgent need for second-line treatment strategies for pediatric patients with multiple sclerosis (MS). OBJECTIVE To report the use of natalizumab in pediatric MS. Natalizumab, a humanized monoclonal antibody targeting α4 integrin, is effective against active relapsing-remitting MS in adults. DESIGN Retrospective study. SETTING Eleven centers for neurology and pediatric neurology in Germany and Austria. PARTICIPANTS A total of 20 pediatric patients with MS who started treatment with natalizumab prior to 18 years of age. These patients underwent magnetic resonance imaging as clinically indicated, despite the fact that 19 of these 20 patients were undergoing first-line disease-modifying therapy. The mean (SD) age at initiation of natalizumab therapy was 16.7 (1.1) years, and the mean (SD) pretreatment period was 18 (10) months. INTERVENTION Natalizumab, 300 mg every 4 weeks. MAIN OUTCOME MEASURES Annualized relapse rates, Expanded Disability Status Scale scores, number of new T2/fluid-attenuated inversion recovery lesions and contrast-enhancing lesions on magnetic resonance imaging, number of adverse events, the prevalence of neutralizing antibodies against natalizumab, and serum JC virus-antibody status. RESULTS Treatment with natalizumab was associated with reductions in mean annualized relapse rates (3.7 without treatment vs 0.4 with treatment; P < .001), median Expanded Disability Status Scale scores (2 without treatment vs 1 with treatment; P < .02), and mean number of new T2/fluid-attenuated inversion recovery lesions per year (7.8 without treatment vs 0.5 with treatment; P < .001). Two patients developed high-titer neutralizing antibodies against natalizumab and had to stop therapy. Adverse events included headaches, asthenia, infections, and hypersensitivity. Abnormal laboratory results were found for 8 patients. JC virus antibodies were found in 5 of 13 patients. After the discontinuation of natalizumab therapy, relapse activity occurred in 6 of 8 patients within 6 months. CONCLUSIONS AND RELEVANCE Our data indicate that natalizumab may be safe and effective against MS in pediatric patients with breakthrough disease.

Evaluation of the 2010 McDonald multiple sclerosis criteria in children with a clinically isolated syndrome

Background: Magnetic resonance imaging diagnostic criteria for paediatric multiple sclerosis have been established on the basis of brain imaging findings alone. The 2010 McDonald criteria for the diagnosis of multiple sclerosis, however, include spinal cord imaging for detection of lesion dissemination in space. The new criteria have been recommended in paediatric multiple sclerosis. Objective: (1) To evaluate the 2010 McDonald multiple sclerosis criteria in children with a clinically isolated syndrome and to compare them with recently proposed magnetic resonance criteria for children; (2) to assess whether the inclusion of spinal cord imaging provided additional value to the 2010 McDonald criteria. Methods: We performed a retrospective analysis of brain and spinal cord magnetic resonance imaging scans from 52 children with a clinically isolated syndrome. Sensitivity, specificity and accuracy of the magnetic resonance criteria were assessed. Results and conclusion: The 2010 McDonald dissemination in space criteria were more sensitive (85% versus 74%) but less specific (80% versus 100%) compared to the 2005 McDonald criteria. The Callen criteria were more accurate (89%) compared to the 2010 McDonald (85%), the 2005 McDonald criteria for dissemination in space (81%), the KIDMUS criteria (46%) and the Canadian Pediatric Demyelinating Disease Network criteria (76%). The 2010 McDonald criteria for dissemination in time were more accurate (93%) than the dissemination in space criteria (85%). Inclusion of the spinal cord did not increase the accuracy of the McDonald criteria.

Oligoclonal bands predict multiple sclerosis in children with optic neuritis

We retrospectively evaluated predictors of conversion to multiple sclerosis (MS) in 357 children with isolated optic neuritis (ON) as a first demyelinating event who had a median follow‐up of 4.0 years. Multiple Cox proportional‐hazards regressions revealed abnormal cranial magnet resonance imaging (cMRI; hazard ratio [HR] = 5.94, 95% confidence interval [CI] = 3.39–10.39, p < 0.001), presence of cerebrospinal fluid immunoglobulin G oligoclonal bands (OCB; HR = 3.69, 95% CI = 2.32–5.86, p < 0.001), and age (HR = 1.08 per year of age, 95% CI = 1.02–1.13, p = 0.003) as independent predictors of conversion, whereas sex and laterality (unilateral vs bilateral) had no influence. Combined cMRI and OCB positivity indicated a 26.84‐fold higher HR for developing MS compared to double negativity (95% CI = 12.26−58.74, p < 0.001). Accordingly, cerebrospinal fluid analysis may supplement cMRI to determine the risk of MS in children with isolated ON. Ann Neurol 2015;77:1076–1082

Antibodies to MOG and AQP4 in children with neuromyelitis optica and limited forms of the disease.

Objective To determine the frequency and clinical-radiological associations of antibodies to myelin oligodendrocyte glycoprotein (MOG) and aquaporin-4 (AQP4) in children presenting with neuromyelitis optica (NMO) and limited forms. Methods Children with a first event of NMO, recurrent (RON), bilateral ON (BON), longitudinally extensive transverse myelitis (LETM) or brainstem syndrome (BS) with a clinical follow-up of more than 12 months were enrolled. Serum samples were tested for MOG- and AQP4-antibodies using live cell-based assays. Results 45 children with NMO (n=12), LETM (n=14), BON (n=6), RON (n=12) and BS (n=1) were included. 25/45 (56%) children had MOG-antibodies at initial presentation (7 NMO, 4 BON, 8 ON, 6 LETM). 5/45 (11%) children showed AQP4-antibodies (3 NMO, 1 LETM, 1 BS) and 15/45 (33%) were seronegative for both antibodies (2 NMO, 2 BON, 4 RON, 7 LETM). No differences were found in the age at presentation, sex ratio, frequency of oligoclonal bands or median EDSS at last follow-up between the three groups. Children with MOG-antibodies more frequently (1) had a monophasic course (p=0.018) after one year, (2) presented with simultaneous ON and LETM (p=0.004) and (3) were less likely to receive immunosuppressive therapies (p=0.0002). MRI in MOG-antibody positive patients (4) less frequently demonstrated periependymal lesions (p=0.001), (5) more often were unspecific (p=0.004) and (6) resolved more frequently (p=0.016). Conclusions 67% of all children presenting with NMO or limited forms tested positive for MOG- or AQP4-antibodies. MOG-antibody positivity was associated with distinct features. We therefore recommend to measure both antibodies in children with demyelinating syndromes.