Publications by authors named "Kathrin Schanda"

49 Publications

Differential Binding of Autoantibodies to MOG Isoforms in Inflammatory Demyelinating Diseases.

Neurol Neuroimmunol Neuroinflamm 2021 07 15;8(5). Epub 2021 Jun 15.

From the Clinical Department of Neurology (K.S., P.P., M.L., B.S., H.H., F.D.P., M.R.), Medical University of Innsbruck, Austria; Euroimmun Medizinische Labordiagnostika AG (S. Mindorf, N.R., C.P.), Lübeck, Germany; Institute for Quality Assurance (ifQ) affiliated to Euroimmun (M.P.), Lübeck, Germany; Department of Pediatrics (E.-M.W.), Olgahospital/Klinikum Stuttgart, Germany; Department of Pediatrics I (C.L., M.B.), Medical University of Innsbruck, Austria; Neurology Unit (S. Mariotto, S.F.), Department of Neuroscience, Biomedicine, and Movement Sciences, University of Verona, Italy; Neuroimmunology and Multiple Sclerosis Unit (A.S.), Service of Neurology, Hospital Clinic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Spain; Beaumont Hospital (M.F.), Dublin, Ireland; Oxford Autoimmune Neurology Group (M.I.S.L., S.R.I., J.P., P.W.), Nuffield Department of Clinical Neurosciences, University of Oxford, UK; Neuroimmunology and MS Research (A.L.), Department of Neurology, University Hospital Zurich & University of Zurich, Switzerland; Institute of Clinical Neuroimmunology (T.K.), Biomedical Center and University Hospital, Ludwig-Maximilians University, Munich, Germany; Department of Neurology (S.V., R.M.), Hospices civils de Lyon, Hôpital neurologique Pierre Wertheimer, France; Paediatric Neurology (K.R.), Witten/Herdecke University, Children's Hospital Datteln, Germany; Department of Neurology (T.B.), Medical University of Vienna, Austria; and Division of Neuropathology and Neurochemistry (R.H.), Department of Neurology, Medical University of Vienna, Austria.

Objective: To analyze serum immunoglobulin G (IgG) antibodies to major isoforms of myelin oligodendrocyte glycoprotein (MOG-alpha 1-3 and beta 1-3) in patients with inflammatory demyelinating diseases.

Methods: Retrospective case-control study using 378 serum samples from patients with multiple sclerosis (MS), patients with non-MS demyelinating disease, and healthy controls with MOG alpha-1-IgG positive (n = 202) or negative serostatus (n = 176). Samples were analyzed for their reactivity to human, mouse, and rat MOG isoforms with and without mutations in the extracellular MOG Ig domain (MOG-ecIgD), soluble MOG-ecIgD, and myelin from multiple species using live cell-based, tissue immunofluorescence assays and ELISA.

Results: The strongest IgG reactivities were directed against the longest MOG isoforms alpha-1 (the currently used standard test for MOG-IgG) and beta-1, whereas the other isoforms were less frequently recognized. Using principal component analysis, we identified 3 different binding patterns associated with non-MS disease: (1) isolated reactivity to MOG-alpha-1/beta-1 (n = 73), (2) binding to MOG-alpha-1/beta-1 and at least one other alpha, but no beta isoform (n = 64), and (3) reactivity to all 6 MOG isoforms (n = 65). The remaining samples were negative (n = 176) for MOG-IgG. These MOG isoform binding patterns were associated with a non-MS demyelinating disease, but there were no differences in clinical phenotypes or disease course. The 3 MOG isoform patterns had distinct immunologic characteristics such as differential binding to soluble MOG-ecIgD, sensitivity to MOG mutations, and binding to human MOG in ELISA.

Conclusions: The novel finding of differential MOG isoform binding patterns could inform future studies on the refinement of MOG-IgG assays and the pathophysiologic role of MOG-IgG.
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http://dx.doi.org/10.1212/NXI.0000000000001027DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8207634PMC
July 2021

Antibodies to MOG in CSF only: pathological findings support the diagnostic value.

Acta Neuropathol 2021 05 20;141(5):801-804. Epub 2021 Feb 20.

Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Policlinico GB Rossi, P.le LA Scuro 10, 37134, Verona, Italy.

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http://dx.doi.org/10.1007/s00401-021-02286-3DOI Listing
May 2021

NfL levels predominantly increase at disease onset in MOG-Abs-associated disorders.

Mult Scler Relat Disord 2021 May 11;50:102833. Epub 2021 Feb 11.

Section of Neurology, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy.

The unpredictable course and uncertain impact of relapses make treatment strategies of anti-myelin oligodendrocyte glycoprotein antibodies associated disorders (MOGAD) challenging. We analysed neurofilament light chain levels (NfL) in onset and follow-up sera of 18 patients with MOGAD to clarify the timing of axonal damage. In comparison with disease onset values (median 8.9 pg/mL, range 1.8-97), NfL levels remained stable or decreased in most follow-up measurements (n=52, median 6.7 pg/mL, range 0.2-207), including those measured on relapses. The predominant axonal damage occurs during onset, which could be the main driving factor of final disability, with subsequent relevant clinical and therapeutic implications.
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http://dx.doi.org/10.1016/j.msard.2021.102833DOI Listing
May 2021

6-month SARS-CoV-2 antibody persistency in a Tyrolian COVID-19 cohort.

Wien Klin Wochenschr 2021 Apr 9;133(7-8):351-358. Epub 2020 Dec 9.

Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.

Background: As coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 evolved only recently, the persistency of the anti-viral antibody response remains to be determined.

Methods: We prospectively followed 29 coronavirus disease 2019 cases, mean age 44 ± 13.2 years. Except for one participant with a pre-existing diagnosis of rheumatoid arthritis, all other participants were previously healthy. We determined anti-viral binding antibodies at 2-10 weeks, 3 months, and 6 months after disease onset as well as neutralizing antibodies at 6 months. Two binding antibody assays were used, targeting the S1 subunit of the spike protein, and the receptor binding domain.

Results: All participants fully recovered spontaneously except for one who had persisting hyposmia. Antibodies to the receptor binding domain persisted for 6 months in all cases with a slight increase of titers, whereas antibodies to S1 dropped below the cut-off point in 2 participants and showed a minimal decrease on average, mainly at month 3 of follow-up in males; however, neutralizing antibodies were detected in all samples at 6 months of follow-up.

Conclusion: There is a stable and persisting antibody response against acute respiratory syndrome coronavirus 2 at 6 months after infection. Neutralizing antibodies confirm virus specificity. As the number of coronavirus disease 2019 convalescent cases is increasing sharply, antibody testing should be implemented to identify immunized individuals. This information can be helpful in various settings of professional and private life.
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http://dx.doi.org/10.1007/s00508-020-01795-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7734454PMC
April 2021

Cerebrospinal fluid findings in patients with myelin oligodendrocyte glycoprotein (MOG) antibodies. Part 2: Results from 108 lumbar punctures in 80 pediatric patients.

J Neuroinflammation 2020 Sep 3;17(1):262. Epub 2020 Sep 3.

Department of Neurology, Medical Faculty, Heinrich Heine University Dusseldorf, Düsseldorf, Germany.

Background: New-generation, cell-based assays have demonstrated a robust association of serum autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis, and brainstem encephalitis, as well as with neuromyelitis optica (NMO)-like or acute-disseminated encephalomyelitis (ADEM)-like presentations. However, only limited data are yet available on cerebrospinal fluid (CSF) findings in MOG-IgG-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disease, MOGAD).

Objective: To describe systematically the CSF profile in children with MOG-EM.

Material And Methods: Cytological and biochemical findings (including white cell counts [WCC] and differentiation; frequency and patterns of oligoclonal bands; IgG/IgM/IgA and albumin concentrations and CSF/serum ratios; intrathecal IgG/IgM/IgA fractions; locally produced IgG/IgM/IgA concentrations; immunoglobulin class patterns; IgG/IgA/IgM reibergrams; Link index; measles/rubella/zoster [MRZ] reaction; other anti-viral and anti-bacterial antibody indices; CSF total protein; CSF L-lactate) from 108 lumbar punctures in 80 pediatric patients of mainly Caucasian descent with MOG-EM were analyzed retrospectively.

Results: Most strikingly, CSF-restricted oligoclonal IgG bands, a hallmark of multiple sclerosis (MS), were absent in 89% of samples (N = 96), and the MRZ reaction, the most specific laboratory marker of MS known so far, in 100% (N = 29). If present at all, intrathecal IgG synthesis was low, often transient and mostly restricted to acute attacks. Intrathecal IgM synthesis was present in 21% and exclusively detectable during acute attacks. CSF WCC were elevated in 54% of samples (median 40 cells/μl; range 6-256; mostly lymphocytes and monocytes; > 100/μl in 11%). Neutrophils were present in 71% of samples; eosinophils, activated lymphocytes, and plasma cells were seen only rarely (all < 7%). Blood-CSF barrier dysfunction (as indicated by an elevated albumin CSF/serum ratio) was present in 46% of all samples (N = 79) and at least once in 48% of all patients (N = 67) tested. CSF alterations were significantly more frequent and/or more pronounced in patients with acute spinal cord or brain disease than in patients with acute ON and varied strongly depending on attack severity. CSF L-lactate levels correlated significantly with the spinal cord lesions load (measured in vertebral segments) in patients with acute myelitis (p = 0.0099). An analysis of pooled data from the pediatric and the adult cohort showed a significant relationship of QAlb (p < 0.0005), CST TP (p < 0.0001), and CSF L-lactate (p < 0.0003) during acute attacks with age.

Conclusion: MOG-IgG-associated EM in children is characterized by CSF features that are distinct from those in MS. With regard to most parameters, no marked differences between the pediatric cohort and the adult cohort analyzed in Part 1 were noted. Our findings are important for the differential diagnosis of pediatric MS and MOG-EM and add to the understanding of the immunopathogenesis of this newly described autoimmune disease.
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http://dx.doi.org/10.1186/s12974-020-01825-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7470445PMC
September 2020

Cerebrospinal fluid findings in patients with myelin oligodendrocyte glycoprotein (MOG) antibodies. Part 1: Results from 163 lumbar punctures in 100 adult patients.

J Neuroinflammation 2020 Sep 3;17(1):261. Epub 2020 Sep 3.

Molecular Neuroimmunology Group, Department of Neurology, University of Heidelberg, Heidelberg, Germany.

Background: New-generation cell-based assays have demonstrated a robust association of serum autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis, and brainstem encephalitis, as well as with neuromyelitis optica (NMO)-like or acute-disseminated encephalomyelitis (ADEM)-like presentations. However, only limited data are yet available on cerebrospinal fluid (CSF) findings in MOG-IgG-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disease, MOGAD).

Objective: To describe systematically the CSF profile in MOG-EM.

Material And Methods: Cytological and biochemical findings (including white cell counts and differentiation; frequency and patterns of oligoclonal bands; IgG/IgM/IgA and albumin concentrations and CSF/serum ratios; intrathecal IgG/IgA/IgM fractions; locally produced IgG/IgM/IgA concentrations; immunoglobulin class patterns; IgG/IgA/IgM reibergrams; Link index; measles/rubella/zoster (MRZ) reaction; other anti-viral and anti-bacterial antibody indices; CSF total protein; CSF L-lactate) from 163 lumbar punctures in 100 adult patients of mainly Caucasian descent with MOG-EM were analyzed retrospectively.

Results: Most strikingly, CSF-restricted oligoclonal IgG bands, a hallmark of multiple sclerosis (MS), were absent in almost 90% of samples (N = 151), and the MRZ reaction, the most specific laboratory marker of MS known so far, in 100% (N = 62). If present, intrathecal IgG (and, more rarely, IgM) synthesis was low, often transient and mostly restricted to acute attacks. CSF WCC was elevated in > 50% of samples (median 31 cells/μl; mostly lymphocytes and monocytes; > 100/μl in 12%). Neutrophils were present in > 40% of samples; activated lymphocytes were found less frequently and eosinophils and/or plasma cells only very rarely (< 4%). Blood-CSF barrier dysfunction (as indicated by an elevated albumin CSF/serum ratio) was present in 48% of all samples and at least once in 55% of all patients (N = 88) tested. The frequency and degree of CSF alterations were significantly higher in patients with acute myelitis than in patients with acute ON and varied strongly depending on attack severity. CSF L-lactate levels correlated significantly with the spinal cord lesion load in patients with acute myelitis (p < 0.0001). Like pleocytosis, blood-CSF barrier dysfunction was present also during remission in a substantial number of patients.

Conclusion: MOG-IgG-positive EM is characterized by CSF features that are distinct from those in MS. Our findings are important for the differential diagnosis of MS and MOG-EM and add to the understanding of the immunopathogenesis of this newly described autoimmune disease.
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http://dx.doi.org/10.1186/s12974-020-01824-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7470615PMC
September 2020

Epidemiology of Pediatric NMOSD in Germany and Austria.

Front Neurol 2020 15;11:415. Epub 2020 May 15.

Department of Pediatric Neurology, Children's Hospital Datteln, University Witten/Herdecke, Datteln, Germany.

Neuromyelitis optica spectrum disorders (NMOSD) are severe inflammatory demyelinating disorders of the central nervous system mainly characterized by recurrent episodes of uni- or bilateral optic neuritis (ON), transverse myelitis (TM) and brainstem syndromes (BS). The majority of adult patients has serum antibodies directed against the water channel protein aquaporin 4 (AQP4-abs). In pediatric patients, AQP4-abs are less, while antibodies against myelin oligodendrocyte glycoprotein (MOG-abs) are more frequently detectable than in adults. Some children with NMOSD have neither AQP4- nor MOG-ab (double-seronegative). Evaluation of epidemiological data regarding incidence and prevalence of pediatric NMOSD in Germany and Austria. We recruited pediatric NMOSD patients between 1 March 2017 and 28 February 2019 with five different tools: (1) ESPED (Surveillance Unit for Rare Pediatric Disorders in Germany), (2) ESNEK (Surveillance for Rare Neurological Disorders during Childhood), (3) pediatric neurology working group within the Austrian Society of Pediatrics and Adolescent Medicine, (4) BIOMARKER Study and (5) NEMOS (Neuromyelitis optica Study Group). We requested data regarding clinical symptoms, antibody status, therapy regimen and response via a standardized questionnaire. During the 2-year recruitment period, 46 (both incidental and prevalent) patients with a suspected diagnosis of NMOSD were brought to our attention. Twenty-two of these patients did not fulfill the inclusion criteria. Of the remaining 24 children, 22 had a median age at onset of 11 (range 3-17) years and 16/22 were female (72.7%) (no data in two patients). Sixteen of 24 patients were AQP4-ab positive (67%), 4/24 MOG-ab positive (16.7%), three children were double-seronegative and in one patient no antibody testing was done. We calculated an incidence rate of 0.022 per 100,000 person-years for Germany, while there was no incidental case in Austria during the recruitment period. The prevalence rate was 0.147 and 0.267 per 100,000 persons in Germany and Austria, respectively. Pediatric NMOSD, with and without associated antibodies, are very rare even considering the different limitations of our study. An unexpected finding was that a considerable proportion of patients was tested neither for AQP4- nor MOG-abs during diagnostic work-up, which should prompt to establish and disseminate appropriate guidelines.
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http://dx.doi.org/10.3389/fneur.2020.00415DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7326092PMC
May 2020

High association of MOG-IgG antibodies in children with bilateral optic neuritis.

Eur J Paediatr Neurol 2020 Jul 15;27:86-93. Epub 2020 Apr 15.

Department of Pediatric Neurology, Children's Hospital Datteln, University Witten/Herdecke, Germany. Electronic address:

Background: Bilateral optic neuritis (bilON) is a rare clinical presentation often thought to be associated with relapsing disorders such as neuromyelitis optica spectrum disorders (NMOSD) or multiple sclerosis (MS).

Objective: To characterize the clinical, radiological phenotype and antibody status of children presenting with bilON.

Material And Methods: Retrospective multicenter study on children with bilON age <18 years with a first episode aquired demyelinating syndrome (ADS), cMRI, AQP4- and serum MOG-antibody status and follow-up data were collected.

Results: 30 patients (f:m = 15:15, median age 8.0y) with bilON met the inclusion criteria. 22/30 (73%) were MOG-positive (median: 1:1280, range: 1:160-1:1520). No patient showed AQP4-abs. 4/30 patients (13%), all with high MOG-abs titers, had recurrent episodes. No patient developed MS. Improvement after IVMP was observed in most patients (26/30; 87%). Outcome was favorable with no sequelae in 22/30 patients. Serial MOG-abs titers tested in 15/22 patients decreased to a median of 1:160 (range: 0-1:640) over a period of 31 months (range: 2-141 months) in 14/15 (93%) patients. MR imaging showed a predominantly anterior affection of the visual system in seropositive patients with bilateral intraorbital lesions in 68% (15/22), compared to 25% in MOG-negative patients (2/8).

Conclusion: Pediatric bilON is associated with high MOG-abs titers in combination with anterior involvement of the visual system. Despite severe loss of vision, the majority of patients shows distinct recovery after IVMP.
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http://dx.doi.org/10.1016/j.ejpn.2020.04.002DOI Listing
July 2020

Induction of aquaporin 4-reactive antibodies in Lewis rats immunized with aquaporin 4 mimotopes.

Acta Neuropathol Commun 2020 04 15;8(1):49. Epub 2020 Apr 15.

Department Neuroimmunology, Medical University Vienna, Center for Brain Research, Spitalgasse 4, A-1090, Vienna, Austria.

Most cases of neuromyelitis optica spectrum disorders (NMOSD) harbor pathogenic autoantibodies against the water channel aquaporin 4 (AQP4). Binding of these antibodies to AQP4 on astrocytes initiates damage to these cells, which culminates in the formation of large tissue destructive lesions in the central nervous system (CNS). Consequently, untreated patients may become permanently blind or paralyzed. Studies on the induction and breakage of tolerance to AQP4 could be of great benefit for NMOSD patients. So far, however, all attempts to create suitable animal models by active sensitization have failed. We addressed this challenge and identified peptides, which mimic the conformational AQP4 epitopes recognized by pathogenic antibodies of NMOSD patients. Here we show that these mimotopes can induce the production of AQP4-reactive antibodies in Lewis rats. Hence, our results provide a conceptual framework for the formation of such antibodies in NMOSD patients, and aid to improve immunization strategies for the creation of animal models suitable for tolerance studies in this devastating disease.
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http://dx.doi.org/10.1186/s40478-020-00920-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7160927PMC
April 2020

International multicenter examination of MOG antibody assays.

Neurol Neuroimmunol Neuroinflamm 2020 03 5;7(2). Epub 2020 Feb 5.

From the Clinical Department of Neurology (M. Reindl, K.S., M. Ramberger, H.H.), Medical University of Innsbruck, Innsbruck, Austria; Oxford Autoimmune Neurology Group (M.W., M. Ramberger, M.I.L., J.P., S.R.I., P.W.), Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom; Brain Autoimmunity Group (F.T., S.R., R.C.D., F.B.), Kids Neuroscience Centre at Kids Research at the Children's Hospital at Westmead, Brain and Mind Centre, University of Sydney, New South Wales, Australia; Department of Neurology (J.S., J.P.F., J.M., E.P.F., S.J.P.), Mayo Clinic, Rochester, MN; Euroimmun Medizinische Labordiagnostika AG (B.T., S.M., N.R., U.K., W.S., C.P.), Lübeck, Germany; Institute for Quality Assurance (ifQ) affiliated to Euroimmun (J.E., M.P.), Lübeck, Germany; Paediatric Neurology (K.R.), Witten/Herdecke University, Children's Hospital Datteln, Datteln, Germany; and Department of Neurology (T.B.), Medical University of Vienna, Austria.

Objective: To compare the reproducibility of 11 antibody assays for immunoglobulin (Ig) G and IgM myelin oligodendrocyte glycoprotein antibodies (MOG-IgG and MOG-IgM) from 5 international centers.

Methods: The following samples were analyzed: MOG-IgG clearly positive sera (n = 39), MOG-IgG low positive sera (n = 39), borderline negative sera (n = 13), clearly negative sera (n = 40), and healthy blood donors (n = 30). As technical controls, 18 replicates (9 MOG-IgG positive and 9 negative) were included. All samples and controls were recoded, aliquoted, and distributed to the 5 testing centers, which performed the following antibody assays: 5 live and 1 fixed immunofluorescence cell-based assays (CBA-IF, 5 MOG-IgG, and 1 MOG-IgM), 3 live flow cytometry cell-based assays (CBA-FACS, all MOG-IgG), and 2 ELISAs (both MOG-IgG).

Results: We found excellent agreement (96%) between the live CBAs for MOG-IgG for samples previously identified as clearly positive or negative from 4 different national testing centers. The agreement was lower with fixed CBA-IF (90%), and the ELISA showed no concordance with CBAs for detection of human MOG-IgG. All CBAs showed excellent interassay reproducibility. The agreement of MOG-IgG CBAs for borderline negative (77%) and particularly low positive (33%) samples was less good. Finally, most samples from healthy blood donors (97%) were negative for MOG-IgG in all CBAs.

Conclusions: Live MOG-IgG CBAs showed excellent agreement for high positive and negative samples at 3 international testing centers. Low positive samples were more frequently discordant than in a similar comparison of aquaporin-4 antibody assays. Further research is needed to improve international standardization for clinical care.
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http://dx.doi.org/10.1212/NXI.0000000000000674DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7051197PMC
March 2020

Relevance of antibodies to myelin oligodendrocyte glycoprotein in CSF of seronegative cases.

Neurology 2019 11 23;93(20):e1867-e1872. Epub 2019 Oct 23.

From the Section of Neurology (S.M., A.G., M.Z., D.A., S.M., S.F.), Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona; Neurology Unit (L.B., R.D., G.S., S.L., M.I.P.), Department of Medical, Surgical, and Experimental Sciences, University of Sassari; Neurology Unit (B.B.), AOUI Verona, Italy; and Clinical Department of Neurology (K.S., M.R.), Medical University of Innsbruck, Austria.

Objective: To determine the diagnostic relevance of myelin oligodendrocyte glycoprotein antibodies (MOG-Abs) in CSF of seronegative cases by retrospectively analyzing consecutive time-matched CSF of 80 MOG-Ab-seronegative patients with demyelinating disease.

Methods: The cohort included 44 patients with NMOSD and related disorders and 36 patients with multiple sclerosis (MS). Two independent neurologists blinded to diagnosis analyzed MOG-Abs by live cell-based immunofluorescence assay with goat anti-human immunoglobulin (Ig) G (whole molecule) antibody. Sera were tested at dilutions of 1:20 and 1:40, and a cutoff of 1:160 was considered for serum positivity. CSF specimens were tested undiluted and at 1:2 dilution with further titrations in case of positivity. Anti-IgG-Fc and anti-IgM-µ secondary antibodies were used to confirm the exclusive presence of MOG-IgG in positive cases. CSF of 13 MOG-Abs seropositive cases and 36 patients with neurodegenerative conditions was analyzed as controls.

Results: Three seronegative cases had CSF MOG-Abs (4% of the whole cohort or 7% of cases excluding patients with MS, in which MOG-Abs seem to lack diagnostic relevance). In particular, 2 patients with neuromyelitis optica spectrum disorder (NMOSD) and 1 with acute disseminated encephalomyelitis had MOG-Abs in CSF. Analysis with anti-IgG-Fc and anti-IgM confirmed the exclusive presence of MOG-IgG in the CSF of these patients. Among the control group, MOG-Abs were detectable in the CSF of 8 of 13 MOG-Ab-seropositive cases and in none of the patients with neurodegenerative disorders.

Conclusion: Although serum is the optimal specimen for MOG-Ab testing, analyzing CSF could improve diagnostic sensitivity in seronegative patients. This observation has relevant diagnostic impact and might provide novel insight into the biological mechanisms of MOG-Ab synthesis.
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http://dx.doi.org/10.1212/WNL.0000000000008479DOI Listing
November 2019

Circulating AQP4-specific auto-antibodies alone can induce neuromyelitis optica spectrum disorder in the rat.

Acta Neuropathol 2019 03 18;137(3):467-485. Epub 2018 Dec 18.

Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Spitalgasse 4, 1090, Vienna, Austria.

It is well established that the binding of pathogenic aquaporin-4 (AQP4)-specific autoantibodies to astrocytes may initiate a cascade of events culminating in the destruction of these cells and in the formation of large tissue-destructive lesions typical for patients with neuromyelitis optica spectrum disorders (NMOSD). To date, not a single experimental study has shown that the systemic presence of the antibody alone can induce any damage to the central nervous system (CNS), while pathological studies on brains of NMOSD patients suggested that there might be ways for antibody entry and subsequent tissue damage. Here, we systemically applied a highly pathogenic, monoclonal antibody with high affinity to AQP4 over prolonged period of time to rats, and show that AQP4-abs can enter the CNS on their own, via circumventricular organs and meningeal or parenchymal blood vessels, that these antibodies initiate the formation of radically different lesions with AQP4 loss, depending on their mode and site of entry, and that lesion formation is much more efficient in the presence of encephalitogenic T-cell responses. We further demonstrate that the established tissue-destructive lesions trigger the formation of additional lesions by short and far reaching effects on blood vessels and their branches, and that AQP4-abs have profound effects on the AQP4 expression in peripheral tissues which counter-act possible titer loss by antibody absorption outside the CNS. Cumulatively, these data indicate that directly induced pathological changes caused by AQP4-abs inside and outside the CNS are efficient drivers of disease evolution in seropositive organisms.
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http://dx.doi.org/10.1007/s00401-018-1950-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6514074PMC
March 2019

MRI of the first event in pediatric acquired demyelinating syndromes with antibodies to myelin oligodendrocyte glycoprotein.

J Neurol 2018 Apr 8;265(4):845-855. Epub 2018 Feb 8.

Department of Pediatric Neurology, Children's Hospital Datteln, Witten/Herdecke University, Datteln, Germany.

Antibodies against the myelin oligodendrocyte glycoprotein (MOG-Ab) can be detected in various pediatric acquired demyelinating syndromes (ADS). Here, we analyze the spectrum of neuroradiologic findings in children with MOG-Ab and a first demyelinating event. The cerebral and spinal MRI of 69 children with different ADS was assessed in regard to the distribution and characteristics of lesions. Children with acute disseminated encephalomyelitis (n = 36) or neuromyelitis optica spectrum disorder (n = 5) presented an imaging pattern characterized predominantly by poorly demarcated lesions with a wide supra- and infratentorial distribution. Younger children also tended to have poorly defined and widespread lesions. The majority of patients with an isolated optic neuritis (n = 16) only presented small non-specific brain lesions or none at all. A longitudinally extensive transverse myelitis mainly affecting the cervical, and less often so the thoracic, lumbar, and conus regions, was detected in 31 children. The three children of our cohort who were then finally diagnosed with multiple sclerosis had at onset already demarcated white matter lesions as well as transverse myelitis. In conclusion, children with MOG seropositive ADS present disparate, yet characteristic imaging patterns. These patterns have been seen to correlate to the disease entity as well as to age of symptom onset.
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http://dx.doi.org/10.1007/s00415-018-8781-3DOI Listing
April 2018

Human antibodies against the myelin oligodendrocyte glycoprotein can cause complement-dependent demyelination.

J Neuroinflammation 2017 Oct 25;14(1):208. Epub 2017 Oct 25.

Clinical Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.

Background: Antibodies to the myelin oligodendrocyte glycoprotein (MOG) are associated with a subset of inflammatory demyelinating diseases of the central nervous system such as acute disseminated encephalomyelitis and neuromyelitis optica spectrum disorders. However, whether human MOG antibodies are pathogenic or an epiphenomenon is still not completely clear. Although MOG is highly conserved within mammals, previous findings showed that not all human MOG antibodies bind to rodent MOG. We therefore hypothesized that human MOG antibody-mediated pathology in animal models may only be evident using species-specific MOG antibodies.

Methods: We screened 80 human MOG antibody-positive samples for their reactivity to mouse and rat MOG using either a live cell-based assay or immunohistochemistry on murine, rat, and human brain tissue. Selected samples reactive to either human MOG or rodent MOG were subsequently tested for their ability to induce complement-mediated damage in murine organotypic brain slices or enhance demyelination in an experimental autoimmune encephalitis (EAE) model in Lewis rats. The MOG monoclonal antibody 8-18-C5 was used as a positive control.

Results: Overall, we found that only a subset of human MOG antibodies are reactive to mouse (48/80, 60%) or rat (14/80, 18%) MOG. Purified serum antibodies from 10 human MOG antibody-positive patients (8/10 reactive to mouse MOG, 6/10 reactive to rat MOG), 3 human MOG-negative patients, and 3 healthy controls were tested on murine organotypic brain slices. Purified IgG from one patient with high titers of anti-human, mouse, and rat MOG antibodies and robust binding to myelin tissue produced significant, complement-mediated myelin loss in organotypic brain slices, but not in the EAE model. Monoclonal 8-18-C5 MOG antibody caused complement-mediated demyelination in both the organotypic brain slice model and in EAE.

Conclusion: This study shows that a subset of human MOG antibodies can induce complement-dependent pathogenic effects in a murine ex vivo animal model. Moreover, a high titer of species-specific MOG antibodies may be critical for demyelinating effects in mouse and rat animal models. Therefore, both the reactivity and titer of human MOG antibodies must be considered for future pathogenicity studies.
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http://dx.doi.org/10.1186/s12974-017-0984-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5657084PMC
October 2017

Clinical spectrum and IgG subclass analysis of anti-myelin oligodendrocyte glycoprotein antibody-associated syndromes: a multicenter study.

J Neurol 2017 Dec 23;264(12):2420-2430. Epub 2017 Oct 23.

Clinical Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.

Anti-myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) recently emerged as a potential biomarker in patients with inflammatory demyelinating diseases of the central nervous system. We here compare the clinical and laboratory findings observed in a cohort of MOG-Ab seropositive and seronegative cases and describe IgG subclass analysis results. Consecutive serum samples referred to Verona University Neuropathology Laboratory for aquaporin-4 (AQP4)-Ab and/or MOG-Ab testing were analysed between March 2014 and May 2017. The presence of AQP4-Ab was determined using a cell-based assay. A live cell immunofluorescence assay was used for the detection of MOG-IgG and IgG subclass analysis. Among 454 analysed samples, 29 were excluded due to AQP4-Ab positivity or to the final demonstration of a disorder not compatible with MOG-Ab. We obtained clinical data in 154 out of 425 cases. Of these, 22 subjects resulted MOG-Ab positive. MOG-Ab positive patients were mainly characterised by the involvement of the optic nerve and/or spinal cord. Half of the cases presented relapses and the recovery was usually partial. Brain MRI was heterogeneous while short lesions were the prevalent observation on spinal cord MRI. MOG-Ab titre usually decreased in non-relapsing cases. In all MOG-IgG positive cases, we observed IgG1 antibodies, which were predominant in most subjects. IgG2 (5/22), IgG3 (9/22) and IgG4 (3/22) antibodies were also detectable. We confirm that MOG-Ab-related syndromes have distinct features in the spectrum of demyelinating conditions, and we describe the possible role of the different IgG subclasses in this condition.
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http://dx.doi.org/10.1007/s00415-017-8635-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5688213PMC
December 2017

Prognostic relevance of MOG antibodies in children with an acquired demyelinating syndrome.

Neurology 2017 Aug 2;89(9):900-908. Epub 2017 Aug 2.

Author affiliations are provided at the end of the article.

Objective: To assess the prognostic value of MOG antibodies (abs) in the differential diagnosis of acquired demyelinating syndromes (ADS).

Methods: Clinical course, MRI, MOG-abs, AQP4-abs, and CSF cells and oligoclonal bands (OCB) in children with ADS and 24 months of follow-up were reviewed in this observational prospective multicenter hospital-based study.

Results: Two hundred ten children with ADS were included and diagnosed with acute disseminated encephalomyelitis (ADEM) (n = 60), neuromyelitis optica spectrum disorder (NMOSD) (n = 12), clinically isolated syndrome (CIS) (n = 101), and multiple sclerosis (MS) (n = 37) after the first episode. MOG-abs were predominantly found in ADEM (57%) and less frequently in NMOSD (25%), CIS (25%), or MS (8%). Increased MOG-ab titers were associated with younger age ( = 0.0001), diagnosis of ADEM ( = 0.005), increased CSF cell counts ( = 0.011), and negative OCB ( = 0.012). At 24-month follow-up, 96 children had no further relapses. Thirty-five children developed recurrent non-MS episodes (63% MOG-, 17% AQP4-abs at onset). Seventy-nine children developed MS (4% MOG-abs at onset). Recurrent non-MS episodes were associated with high MOG-ab titers ( = 0.0003) and older age at onset ( = 0.024). MS was predicted by MS-like MRI ( < 0.0001) and OCB ( = 0.007). An MOG-ab cutoff titer ≥1:1,280 predicted a non-MS course with a sensitivity of 47% and a specificity of 100% and a recurrent non-MS course with a sensitivity of 46% and a specificity of 86%.

Conclusions: Our results show that the presence of MOG-abs strongly depends on the age at disease onset and that high MOG-ab titers were associated with a recurrent non-MS disease course.
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http://dx.doi.org/10.1212/WNL.0000000000004312DOI Listing
August 2017

MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 3: Brainstem involvement - frequency, presentation and outcome.

J Neuroinflammation 2016 11 1;13(1):281. Epub 2016 Nov 1.

Molecular Neuroimmunology Group, Department of Neurology, University Hospital Heidelberg, Otto Meyerhof Center, Im Neuenheimer Feld 350, 69120, Heidelberg, Germany.

Background: Myelin oligodendrocyte glycoprotein antibodies (MOG-IgG) are present in a subset of aquaporin-4 (AQP4)-IgG-negative patients with optic neuritis (ON) and/or myelitis. Little is known so far about brainstem involvement in MOG-IgG-positive patients.

Objective: To investigate the frequency, clinical and paraclinical features, course, outcome, and prognostic implications of brainstem involvement in MOG-IgG-positive ON and/or myelitis.

Methods: Retrospective case study.

Results: Among 50 patients with MOG-IgG-positive ON and/or myelitis, 15 (30 %) with a history of brainstem encephalitis were identified. All were negative for AQP4-IgG. Symptoms included respiratory insufficiency, intractable nausea and vomiting (INV), dysarthria, dysphagia, impaired cough reflex, oculomotor nerve palsy and diplopia, nystagmus, internuclear ophthalmoplegia (INO), facial nerve paresis, trigeminal hypesthesia/dysesthesia, vertigo, hearing loss, balance difficulties, and gait and limb ataxia; brainstem involvement was asymptomatic in three cases. Brainstem inflammation was already present at or very shortly after disease onset in 7/15 (47 %) patients. 16/21 (76.2 %) brainstem attacks were accompanied by acute myelitis and/or ON. Lesions were located in the pons (11/13), medulla oblongata (8/14), mesencephalon (cerebral peduncles; 2/14), and cerebellar peduncles (5/14), were adjacent to the fourth ventricle in 2/12, and periaqueductal in 1/12; some had concomitant diencephalic (2/13) or cerebellar lesions (1/14). MRI or laboratory signs of blood-brain barrier damage were present in 5/12. Cerebrospinal fluid pleocytosis was found in 11/14 cases, with neutrophils in 7/11 (3-34 % of all CSF white blood cells), and oligoclonal bands in 4/14. Attacks were preceded by acute infection or vaccination in 5/15 (33.3 %). A history of teratoma was noted in one case. The disease followed a relapsing course in 13/15 (87 %); the brainstem was involved more than once in 6. Immunosuppression was not always effective in preventing relapses. Interferon-beta was followed by new attacks in two patients. While one patient died from central hypoventilation, partial or complete recovery was achieved in the remainder following treatment with high-dose steroids and/or plasma exchange. Brainstem involvement was associated with a more aggressive general disease course (higher relapse rate, more myelitis attacks, more frequently supratentorial brain lesions, worse EDSS at last follow-up).

Conclusions: Brainstem involvement is present in around one third of MOG-IgG-positive patients with ON and/or myelitis. Clinical manifestations are diverse and may include symptoms typically seen in AQP4-IgG-positive neuromyelitis optica, such as INV and respiratory insufficiency, or in multiple sclerosis, such as INO. As MOG-IgG-positive brainstem encephalitis may take a serious or even fatal course, particular attention should be paid to signs or symptoms of additional brainstem involvement in patients presenting with MOG-IgG-positive ON and/or myelitis.
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http://dx.doi.org/10.1186/s12974-016-0719-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5088671PMC
November 2016

MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 2: Epidemiology, clinical presentation, radiological and laboratory features, treatment responses, and long-term outcome.

J Neuroinflammation 2016 09 27;13(1):280. Epub 2016 Sep 27.

Molecular Neuroimmunology Group, Department of Neurology, University of Heidelberg, Heidelberg, Germany.

Background: A subset of patients with neuromyelitis optica spectrum disorders (NMOSD) has been shown to be seropositive for myelin oligodendrocyte glycoprotein antibodies (MOG-IgG).

Objective: To describe the epidemiological, clinical, radiological, cerebrospinal fluid (CSF), and electrophysiological features of a large cohort of MOG-IgG-positive patients with optic neuritis (ON) and/or myelitis (n = 50) as well as attack and long-term treatment outcomes.

Methods: Retrospective multicenter study.

Results: The sex ratio was 1:2.8 (m:f). Median age at onset was 31 years (range 6-70). The disease followed a multiphasic course in 80 % (median time-to-first-relapse 5 months; annualized relapse rate 0.92) and resulted in significant disability in 40 % (mean follow-up 75 ± 46.5 months), with severe visual impairment or functional blindness (36 %) and markedly impaired ambulation due to paresis or ataxia (25 %) as the most common long-term sequelae. Functional blindess in one or both eyes was noted during at least one ON attack in around 70 %. Perioptic enhancement was present in several patients. Besides acute tetra-/paraparesis, dysesthesia and pain were common in acute myelitis (70 %). Longitudinally extensive spinal cord lesions were frequent, but short lesions occurred at least once in 44 %. Fourty-one percent had a history of simultaneous ON and myelitis. Clinical or radiological involvement of the brain, brainstem, or cerebellum was present in 50 %; extra-opticospinal symptoms included intractable nausea and vomiting and respiratory insufficiency (fatal in one). CSF pleocytosis (partly neutrophilic) was present in 70 %, oligoclonal bands in only 13 %, and blood-CSF-barrier dysfunction in 32 %. Intravenous methylprednisolone (IVMP) and long-term immunosuppression were often effective; however, treatment failure leading to rapid accumulation of disability was noted in many patients as well as flare-ups after steroid withdrawal. Full recovery was achieved by plasma exchange in some cases, including after IVMP failure. Breakthrough attacks under azathioprine were linked to the drug-specific latency period and a lack of cotreatment with oral steroids. Methotrexate was effective in 5/6 patients. Interferon-beta was associated with ongoing or increasing disease activity. Rituximab and ofatumumab were effective in some patients. However, treatment with rituximab was followed by early relapses in several cases; end-of-dose relapses occurred 9-12 months after the first infusion. Coexisting autoimmunity was rare (9 %). Wingerchuk's 2006 and 2015 criteria for NMO(SD) and Barkhof and McDonald criteria for multiple sclerosis (MS) were met by 28 %, 32 %, 15 %, 33 %, respectively; MS had been suspected in 36 %. Disease onset or relapses were preceded by infection, vaccination, or pregnancy/delivery in several cases.

Conclusion: Our findings from a predominantly Caucasian cohort strongly argue against the concept of MOG-IgG denoting a mild and usually monophasic variant of NMOSD. The predominantly relapsing and often severe disease course and the short median time to second attack support the use of prophylactic long-term treatments in patients with MOG-IgG-positive ON and/or myelitis.
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http://dx.doi.org/10.1186/s12974-016-0718-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5086042PMC
September 2016

MOG-IgG in NMO and related disorders: a multicenter study of 50 patients. Part 1: Frequency, syndrome specificity, influence of disease activity, long-term course, association with AQP4-IgG, and origin.

J Neuroinflammation 2016 09 26;13(1):279. Epub 2016 Sep 26.

Clinical Department of Neurology, Medical University Innsbruck, Innsbruck, Austria.

Background: Antibodies to myelin oligodendrocyte glycoprotein (MOG-IgG) have been suggested to play a role in a subset of patients with neuromyelitis optica and related disorders.

Objective: To assess (i) the frequency of MOG-IgG in a large and predominantly Caucasian cohort of patients with optic neuritis (ON) and/or myelitis; (ii) the frequency of MOG-IgG among AQP4-IgG-positive patients and vice versa; (iii) the origin and frequency of MOG-IgG in the cerebrospinal fluid (CSF); (iv) the presence of MOG-IgG at disease onset; and (v) the influence of disease activity and treatment status on MOG-IgG titers.

Methods: 614 serum samples from patients with ON and/or myelitis and from controls, including 92 follow-up samples from 55 subjects, and 18 CSF samples were tested for MOG-IgG using a live cell-based assay (CBA) employing full-length human MOG-transfected HEK293A cells.

Results: MOG-IgG was detected in 95 sera from 50 patients with ON and/or myelitis, including 22/54 (40.7 %) patients with a history of both ON and myelitis, 22/103 (21.4 %) with a history of ON but no myelitis and 6/45 (13.3 %) with a history of longitudinally extensive transverse myelitis but no ON, and in 1 control patient with encephalitis and a connective tissue disorder, all of whom were negative for AQP4-IgG. MOG-IgG was absent in 221 further controls, including 83 patients with AQP4-IgG-seropositive neuromyelitis optica spectrum disorders and 85 with multiple sclerosis (MS). MOG-IgG was found in 12/18 (67 %) CSF samples from MOG-IgG-seropositive patients; the MOG-IgG-specific antibody index was negative in all cases, indicating a predominantly peripheral origin of CSF MOG-IgG. Serum and CSF MOG-IgG belonged to the complement-activating IgG1 subclass. MOG-IgG was present already at disease onset. The antibodies remained detectable in 40/45 (89 %) follow-up samples obtained over a median period of 16.5 months (range 0-123). Serum titers were higher during attacks than during remission (p < 0.0001), highest during attacks of simultaneous myelitis and ON, lowest during acute isolated ON, and declined following treatment.

Conclusions: To date, this is the largest cohort studied for IgG to human full-length MOG by means of an up-to-date CBA. MOG-IgG is present in a substantial subset of patients with ON and/or myelitis, but not in classical MS. Co-existence of MOG-IgG and AQP4-IgG is highly uncommon. CSF MOG-IgG is of extrathecal origin. Serum MOG-IgG is present already at disease onset and remains detectable in the long-term course. Serum titers depend on disease activity and treatment status.
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http://dx.doi.org/10.1186/s12974-016-0717-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5084340PMC
September 2016

Aquaporin 4-specific T cells and NMO-IgG cause primary retinal damage in experimental NMO/SD.

Acta Neuropathol Commun 2016 08 8;4(1):82. Epub 2016 Aug 8.

Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Spitalgasse 4, A-1090, Vienna, Austria.

Neuromyelitis optica/spectrum disorder (NMO/SD) is a severe, inflammatory disease of the central nervous system (CNS). In the majority of patients, it is associated with the presence of pathogenic serum autoantibodies (the so-called NMO-IgGs) directed against the water channel aquaporin 4 (AQP4), and with the formation of large, astrocyte-destructive lesions in spinal cord and optic nerves. A large number of recent studies using optical coherence tomography (OCT) demonstrated that damage to optic nerves in NMO/SD is also associated with retinal injury, as evidenced by retinal nerve fiber layer (RNFL) thinning and microcystic inner nuclear layer abnormalities. These studies concluded that retinal injury in NMO/SD patients results from secondary neurodegeneration triggered by optic neuritis.However, the eye also contains cells expressing AQP4, i.e., Müller cells and astrocytes in the retina, epithelial cells of the ciliary body, and epithelial cells of the iris, which raised the question whether the eye can also be a primary target in NMO/SD. Here, we addressed this point in experimental NMO/SD (ENMO) induced in Lewis rat by transfer of AQP4268-285-specific T cells and NMO-IgG.We show that these animals show retinitis and subsequent dysfunction/damage of retinal axons and neurons, and that this pathology occurs independently of the action of NMO-IgG. We further show that in the retinae of ENMO animals Müller cell side branches lose AQP4 reactivity, while retinal astrocytes and Müller cell processes in the RNFL/ganglionic cell layers are spared. These changes only occur in the presence of both AQP4268-285-specific T cells and NMO-IgG.Cumulatively, our data show that damage to retinal cells can be a primary event in NMO/SD.
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http://dx.doi.org/10.1186/s40478-016-0355-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4977668PMC
August 2016

Characterization of the binding pattern of human aquaporin-4 autoantibodies in patients with neuromyelitis optica spectrum disorders.

J Neuroinflammation 2016 07 1;13(1):176. Epub 2016 Jul 1.

Clinical Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.

Background: The discovery of a highly specific antibody against the aquaporin-4 (AQP4) water channel (AQP4-IgG) unified the spectrum of neuromyelitis optica spectrum disorders (NMOSD), which are considered to be antibody-mediated autoimmune diseases. The AQP4 water channel is located on astrocytic end-feet processes and consists of six transmembrane helical domains forming three extracellular loops A, C, and E in which defined amino acids were already proven to be critical for AQP4-IgG binding. However, the clinical relevance of these findings is unclear. Therefore, we have characterized the epitope specificity of AQP4-IgG-positive NMOSD patients.

Methods: We established a cell-based flow cytometry assay for the quantitative detection of AQP4-IgG-positive serum samples. Human embryonic kidney (HEK) cells were transiently transfected with an EmGFP-tagged AQP4-M23, AQP4-M1, or six AQP4-M23 extracellular loop mutants including two mutations in loop A (serial AA substitution, insertion of a myc-tag), two in loop C (N153Q, insertion of a myc-tag), and two in loop E (H230G, insertion of a myc-tag). Fourty-seven baseline and 49 follow-up serum samples and six paired cerebrospinal fluid (CSF) baseline samples of 47 AQP4-IgG-positive Austrian NMOSD patients were then tested for their binding capability to AQP4-M1 and AQP4-M23 isoforms and these six extracellular loop mutants.

Results: Overall, we could identify two broad patterns of antibody recognition based on differential sensitivity to mutations in extracellular loop A. Pattern A was characterized by reduced binding to the two mutations in loop A, whereas pattern B had only partial or no reduced binding to these mutations. These two patterns were not associated with significant differences in demographic and clinical parameters or serum titers in this retrospective study. Interestingly, we found a change of AQP4-IgG epitope recognition pattern in seven of 20 NMOSD patients with available follow-up samples. Moreover, we found different binding patterns in five of six paired CSF versus serum samples, with a predominance of pattern A in CSF.

Conclusions: Our study demonstrates that AQP4-IgG in sera of NMOSD patients show distinct patterns of antibody recognition. The clinical and diagnostic relevance of these findings have to be addressed in prospective studies.
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http://dx.doi.org/10.1186/s12974-016-0642-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4930584PMC
July 2016

Multicentre comparison of a diagnostic assay: aquaporin-4 antibodies in neuromyelitis optica.

J Neurol Neurosurg Psychiatry 2016 09 25;87(9):1005-15. Epub 2016 Apr 25.

Department of Immunology, Istanbul University, Institute of Experimental Medicine, Istanbul, Turkey.

Objective: Antibodies to cell surface central nervous system proteins help to diagnose conditions which often respond to immunotherapies. The assessment of antibody assays needs to reflect their clinical utility. We report the results of a multicentre study of aquaporin (AQP) 4 antibody (AQP4-Ab) assays in neuromyelitis optica spectrum disorders (NMOSD).

Methods: Coded samples from patients with neuromyelitis optica (NMO) or NMOSD (101) and controls (92) were tested at 15 European diagnostic centres using 21 assays including live (n=3) or fixed cell-based assays (n=10), flow cytometry (n=4), immunohistochemistry (n=3) and ELISA (n=1).

Results: Results of tests on 92 controls identified 12assays as highly specific (0-1 false-positive results). 32 samples from 50 (64%) NMO sera and 34 from 51 (67%) NMOSD sera were positive on at least two of the 12 highly specific assays, leaving 35 patients with seronegative NMO/spectrum disorder (SD). On the basis of a combination of clinical phenotype and the highly specific assays, 66 AQP4-Ab seropositive samples were used to establish the sensitivities (51.5-100%) of all 21 assays. The specificities (85.8-100%) were based on 92 control samples and 35 seronegative NMO/SD patient samples.

Conclusions: The cell-based assays were most sensitive and specific overall, but immunohistochemistry or flow cytometry could be equally accurate in specialist centres. Since patients with AQP4-Ab negative NMO/SD require different management, the use of both appropriate control samples and defined seronegative NMOSD samples is essential to evaluate these assays in a clinically meaningful way. The process described here can be applied to the evaluation of other antibody assays in the newly evolving field of autoimmune neurology.
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http://dx.doi.org/10.1136/jnnp-2015-312601DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5013123PMC
September 2016

Experimental Neuromyelitis Optica Induces a Type I Interferon Signature in the Spinal Cord.

PLoS One 2016 18;11(3):e0151244. Epub 2016 Mar 18.

Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Vienna, Austria.

Neuromyelitis optica (NMO) is an acute inflammatory disease of the central nervous system (CNS) which predominantly affects spinal cord and optic nerves. Most patients harbor pathogenic autoantibodies, the so-called NMO-IgGs, which are directed against the water channel aquaporin 4 (AQP4) on astrocytes. When these antibodies gain access to the CNS, they mediate astrocyte destruction by complement-dependent and by antibody-dependent cellular cytotoxicity. In contrast to multiple sclerosis (MS) patients who benefit from therapies involving type I interferons (I-IFN), NMO patients typically do not profit from such treatments. How is I-IFN involved in NMO pathogenesis? To address this question, we made gene expression profiles of spinal cords from Lewis rat models of experimental neuromyelitis optica (ENMO) and experimental autoimmune encephalomyelitis (EAE). We found an upregulation of I-IFN signature genes in EAE spinal cords, and a further upregulation of these genes in ENMO. To learn whether the local I-IFN signature is harmful or beneficial, we induced ENMO by transfer of CNS antigen-specific T cells and NMO-IgG, and treated the animals with I-IFN at the very onset of clinical symptoms, when the blood-brain barrier was open. With this treatment regimen, we could amplify possible effects of the I-IFN induced genes on the transmigration of infiltrating cells through the blood brain barrier, and on lesion formation and expansion, but could avoid effects of I-IFN on the differentiation of pathogenic T and B cells in the lymph nodes. We observed that I-IFN treated ENMO rats had spinal cord lesions with fewer T cells, macrophages/activated microglia and activated neutrophils, and less astrocyte damage than their vehicle treated counterparts, suggesting beneficial effects of I-IFN.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0151244PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4798752PMC
August 2016

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

Mult Scler 2016 12 11;22(14):1821-1829. Epub 2016 Feb 11.

Department of Paediatric Neurology, Children's Hospital Datteln, Witten/Herdecke University, Datteln, Germany

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.
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http://dx.doi.org/10.1177/1352458516631038DOI Listing
December 2016

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

J Neurol Neurosurg Psychiatry 2016 Aug 8;87(8):897-905. Epub 2015 Dec 8.

Department of Pediatric Neurology, Children's Hospital Datteln, University Witten/Herdecke, Datteln, Germany.

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.
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http://dx.doi.org/10.1136/jnnp-2015-311743DOI Listing
August 2016

Fulminant demyelinating encephalomyelitis: Insights from antibody studies and neuropathology.

Neurol Neuroimmunol Neuroinflamm 2015 Dec 4;2(6):e175. Epub 2015 Nov 4.

Clinical Department of Neurology (F.D.P., M.R., R.B., K.S., E.S., T.B.) and Department of Neuroradiology (P.R.), Medical University of Innsbruck; Institute of Neurology (R.H.) and Center for Brain Research (H.L.), Medical University of Vienna, Austria; and Departments of Neurology and Multiple Sclerosis Therapeutics (D.S., K.F.), Tohoku University Graduate School of Medicine, Sendai, Japan.

Objectives: Antibodies to myelin oligodendrocyte glycoprotein (MOG) are detectable in inflammatory demyelinating CNS diseases, and MOG antibody-associated diseases seem to have a better prognosis despite occasionally severe presentations.

Methods: We report the case of a 71-year-old patient with acute visual and gait disturbance that dramatically worsened to bilateral amaurosis, tetraplegia, and respiratory insufficiency within a few days.

Results: MRI showed multiple progressive cerebral and spinal lesions with diffusion restriction (including both optic nerves) and marginal contrast enhancement. Routine blood and CSF measures including oligoclonal bands were normal. At disease onset, MOG immunoglobulin G was detected (serum titer 1:1,280, corresponding CSF titer was 1:20) and remained positive in patient serum. Aquaporin-4 antibodies were absent at disease onset but seroconverted to positive at week 9. In addition, CSF glial fibrillary acid protein and myelin basic protein levels were very high at onset but decreased during disease course. After 4 months, the patient died despite immunomodulatory treatment. Postmortem neuropathologic examination revealed an acute multiple sclerosis (MS) defined by multiple demyelinating lesions with a pronounced destructive component and loss of astrocytes. Lesion pattern of optic chiasm met MS pattern II characterized by antibody and complement-mediated demyelination.

Conclusion: The case with the clinical presentation of an acute demyelinating encephalomyelitis with predominant optic and spinal involvement, absent oligoclonal bands, a histopathology of acute MS pattern II and development of aquaporin-4 antibodies extends the spectrum of MOG antibody-associated encephalomyelitis. Although, MOG antibodies are suspected to indicate a favorable prognosis, fulminant disease courses are possible and warrant an aggressive immunotherapy.
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http://dx.doi.org/10.1212/NXI.0000000000000175DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4635550PMC
December 2015

Highly encephalitogenic aquaporin 4-specific T cells and NMO-IgG jointly orchestrate lesion location and tissue damage in the CNS.

Acta Neuropathol 2015 Dec 3;130(6):783-98. Epub 2015 Nov 3.

Department for Neuroimmunology, Center for Brain Research, Medical University Vienna, Spitalgasse 4, 1090, Vienna, Austria.

In neuromyelitis optica (NMO), astrocytes become targets for pathogenic aquaporin 4 (AQP4)-specific antibodies which gain access to the central nervous system (CNS) in the course of inflammatory processes. Since these antibodies belong to a T cell-dependent subgroup of immunoglobulins, and since NMO lesions contain activated CD4(+) T cells, the question arose whether AQP4-specific T cells might not only provide T cell help for antibody production, but also play an important role in the induction of NMO lesions. We show here that highly pathogenic, AQP4-peptide-specific T cells exist in Lewis rats, which recognize AQP4268-285 as their specific antigen and cause severe panencephalitis. These T cells are re-activated behind the blood-brain barrier and deeply infiltrate the CNS parenchyma of the optic nerves, the brain, and the spinal cord, while T cells with other AQP4-peptide specificities are essentially confined to the meninges. Although AQP4268-285-specific T cells are found throughout the entire neuraxis, they have NMO-typical "hotspots" for infiltration, i.e. periventricular and periaqueductal regions, hypothalamus, medulla, the dorsal horns of spinal cord, and the optic nerves. Most remarkably, together with NMO-IgG, they initiate large astrocyte-destructive lesions which are located predominantly in spinal cord gray matter. We conclude that the processing of AQP4 by antigen presenting cells in Lewis rats produces a highly encephalitogenic AQP4 epitope (AQP4268-285), that T cells specific for this epitope are found in the immune repertoire of normal Lewis rats and can be readily expanded, and that AQP4268-285-specific T cells produce NMO-like lesions in the presence of NMO-IgG.
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http://dx.doi.org/10.1007/s00401-015-1501-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4654751PMC
December 2015

Antibodies to aquaporin-1 are not present in neuromyelitis optica.

Neurol Neuroimmunol Neuroinflamm 2015 Dec 1;2(6):e160. Epub 2015 Oct 1.

Clinical Department of Neurology (K.S., H.H., T.B., M.R.), Medical University of Innsbruck, Austria; Nuffield Department of Clinical Neurosciences (P.W., M.I.L.), University of Oxford, United Kingdom; Department of Neurology (F.A.-D.), Karl Landsteiner Institute for Neuroimmunological and Neurodegenerative Disorders, Sozialmedizinisches Zentrum Ost Donauspital, Vienna, Austria; Department of Neurology (J.P.), Oxford University Hospitals Trust, Oxford, United Kingdom; and Department of Neurology (S.V., R.M.), Lyon University Hospital and Lyon Neurosciences Research Centre, Lyon, France.

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http://dx.doi.org/10.1212/NXI.0000000000000160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592537PMC
December 2015

NMDA receptor antibodies: A rare association in inflammatory demyelinating diseases.

Neurol Neuroimmunol Neuroinflamm 2015 Oct 13;2(5):e141. Epub 2015 Aug 13.

Clinical Department of Neurology (M. Ramberger, G.B., K.S., A.L., F.D., T.B., M. Reindl) and Department of Pediatrics I (K.R., M.B.), Medical University of Innsbruck, Austria; Institute of Neurology (R.H.), Medical University of Vienna, Austria; Pediatric Neurology (K.R.), Witten/Herdecke University, Children's Hospital Datteln, Datteln, Germany; Department of Neurology (F.A.-D.), Karl Landsteiner Institute for Neuroimmunological and Neurodegenerative Disorders, Sozialmedizinisches Zentrum Ost Donauspital, Vienna, Austria; and Neuroimmunology and Multiple Sclerosis Research (A.L.), Department of Neurology, University Hospital Zurich and University of Zurich, Switzerland.

Objectives: To analyze the frequency of NMDA receptor (NMDAR) antibodies in patients with various inflammatory demyelinating diseases of the CNS and to determine their clinical correlates.

Methods: Retrospective case-control study from 2005 to 2014 with the detection of serum IgG antibodies to NMDAR, aquaporin-4, and myelin oligodendrocyte glycoprotein by recombinant live cell-based immunofluorescence assays. Fifty-one patients with acute disseminated encephalomyelitis, 41 with neuromyelitis optica spectrum disorders, 34 with clinically isolated syndrome, and 89 with multiple sclerosis (MS) were included. Due to a known association of NMDAR antibodies with seizures and behavioral symptoms, patients with those clinical manifestations were preferentially included and are therefore overrepresented in our cohort. Nine patients with NMDAR encephalitis, 94 patients with other neurologic diseases, and 48 healthy individuals were used as controls.

Results: NMDAR antibodies were found in all 9 patients with NMDAR encephalitis but in only 1 of 215 (0.5%) patients with inflammatory demyelination and in none of the controls. This patient had relapsing-remitting MS with NMDAR antibodies present at disease onset, with an increase in NMDAR antibody titer with the onset of psychiatric symptoms and cognitive deficits.

Conclusion: In demyelinating disorders, NMDAR antibodies are uncommon, even in those with symptoms seen in NMDAR encephalitis.
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http://dx.doi.org/10.1212/NXI.0000000000000141DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4537309PMC
October 2015
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