anti-MOG IgG Research Articles

Complement-dependent cytotoxicity of human autoantibodies against myelin oligodendrocyte glycoprotein.

The autoantibody to myelin oligodendrocyte glycoprotein (MOG), a component of the central nervous system myelin, has been identified in a subset of demyelinating diseases. However, there is no convincing evidence to support the direct pathogenic contribution of this autoantibody. To elucidate the role of anti-MOG autoantibodies in human demyelinating disorders, we assessed the effect of autoantibodies on MOG-expressing cells. Mammalian cells expressing the human MOG protein reacted with human anti-MOG autoantibodies in the presence or absence of complement. Sera from 86 patients and 11 healthy sera were used. We analyzed anti-MOG antibody titers, IgG subclass, and their cytotoxic ability in sera from patients with various neurological diseases. Membrane attack complex (MAC) formation was examined by detection of complement C9 or C9neo with western blot or flow cytometry. Among 86 patients, 40 were determined to be MOG-IgG-positive and 46 were negative. Anti-MOG-positive sera, but not -negative sera, caused cell death in MOG-expressing cells. This cytotoxic effect was disappeared after heat inactivation of sera. Importantly, anti-MOG IgG and externally added complement were necessary for sufficient cytotoxic effects. Anti-MOG autoantibodies were histologically colocalized with complement and formed a membrane attack complex consisting of anti-MOG IgG and complement factors. The human MOG antibody specifically killed MOG-expressing cells in vitro in the presence of externally added complement. Membrane attack complexes were formed on the cells, indicating that this autoantibody activated complement-mediated cytotoxicity. Further studies in larger numbers of patients are needed to characterize the role of complement in MOGAD.

Mielitis transversa aguda asociada con infección por SARS-CoV-2

In addition to causing respiratory problems, SARS-CoV-2 can cause a wide spectrum of neurological complications such as headaches, ageusia, anosmia, encephalopathy, cerebrovascular disease, Guillain-Barré syndrome and other polyneuropathies, meningoencephalitis, acute necrotizing hemorrhagic encephalopathy, and central nervous system syndromes associated with inflammation. In this review we present 39 cases of acute transverse myelitis (ATM) associated to SARS-CoV-2 infection. All cases had a positive polymerase chain reaction (PCR) nasopharyngeal swab and/or antigen test. Biochemical analyses confirmed the absence of other pathogens and autoantibody-mediated neuroinflammatory disease, except for two cases, one with autoantibodies against the oligodendrocyte myelin glycoprotein (anti-MOG IgG) and another with anti-MOG IgG and anti-glutamic acid decarboxylase (anti-GAD65). Magnetic Resonance Imaging (MRI) studies confirmed the diagnosis of ATM. Although causality cannot be inferred, it is likely that isolated cases of ATM are the consequence of a para or post-infectious process in SARS-CoV-2. In this work, the probable causes of ATM associated with SARS-CoV-2 are discussed. The understanding of the mechanisms behind these neurological disorders triggered by a viral infection will help to optimize the therapeutic strategies for patient management. Keywords: SARS-CoV-2; COVID-19; transverse myelitis; long COVID; demyelination; nervous system.

Anti-myelin Oligodendrocyte Glycoprotein Antibody-Associated Disorder (MOGAD) in a Pediatric Patient with Rare Presentation of a Cerebellar Tumefactive Lesion

Objective NA. Background Anti-myelin oligodendrocyte glycoprotein (MOG) antibodies have been commonly associated with optic neuritis, myelitis, and acute disseminated encephalomyelitis but rarely with tumefactive lesions, especially in children. We report a young child with MOGAD presenting with a tumefactive cerebellar demyelinating lesion. Design/Methods A retrospective chart review Results A 3-year-old developmentally appropriate boy with fever for five days prior presented for gait changes and a self-resolved seizure lasting less than 5 minutes. Neurologic examination showed abnormal finger to nose on the left side, weakness of the left lower extremity and an ataxic gait. The differential at the time was Todd's paralysis versus an intracranial process. MRI showed a non-enhancing, ill-defined T2 hyperintense tumefactive lesion with mass effect within the left cerebellum concerning for tumor, abscess, or demyelination. On EEG, a lack of a well sustained and modulated posterior dominant rhythm and lack of a well-developed anterior to posterior gradient, with moderate background slowing was seen. Cerebrospinal fluid showed 8 white blood cells, 0 red blood cells, 55 mg/dl glucose, 31 mg/dl protein, 0.61 IgG index, and 0 oligoclonal bands. The Mayo Clinic cell-based assay detected anti-MOG IgG antibody in the serum with titer of 1:100. Neurological symptoms gradually improved after steroid pulse therapy. Conclusions This report highlights the novel spectrum of radiologic manifestations associated with MOGAD in pediatric patients and MOGAD should always be considered in the differential diagnosis of tumefactive lesions.

Myelin oligodendrocyte glycoprotein antibodies in genetic leukodystrophies

Accumulation of intermediate metabolites due to enzyme deficiencies and demyelination can provoke inflammation in genetic leukodystrophies. Thirty patients with genetic leukodystrophy and 48 healthy control sera were tested for anti-myelin oligodendrocyte glycoprotein (MOG) antibodies by fixed and/or live cell-based assays. MOG-IgG was detected in two late infantile metachromatic leukodystrophy (MLD) cases, both of which were also weakly positive for IgG1, and one with IgG3 as the dominant anti-MOG IgG subclass. MOG-IgG was borderline positive in a vanishing white matter (VWM) disease patient. These results suggest that inherited metabolic or degenerative processes can have an autoimmune component, possibly as an epiphenomenon.

Investigating myelin oligodendrocyte glycoprotein antibodies in hereditary citrullinemia

Metabolites like lipids, amino acids or peptides can affect the immune system. Citrulline is an amino acid that activates several inflammatory pathways. Serum citrulline levels are markedly elevated in hereditary citrullinemia type 1 (CTLN1), and cases with CTLN1 have have been described with inflammatory lesions of the central nervous system (CNS). This suggests the presence of a relatively proinflammatory state in CTLN1. We therefore tested sera of CTLN1 patients for anti-myelin oligodendrocyte glycoprotein (MOG) antibodies which are a frequent cause of inflammatory CNS disorders in young patients. Patients with CTLN1 (n = 15) and control groups consisting of phenylketonuria (n = 22), juvenile idiopathic arthritis (n = 13), pediatric onset systemic lupus erythematosus (n = 17) and healthy controls (n = 48) were tested for serum anti-MOG IgG and anti-MOG IgG1 antibodies in a live-cell based assay. Serum citrulline levels were elevated in 14/15 CTLN1 patients at the time of the study. No clear anti-MOG IgG positivity was detected in any of the CTLN1 or control groups. One CTLN1 and one healthy control case with anti-MOG IgG titers close to borderline were also tested for MOG-specific IgG1, with similar results. These findings did not support the role of elevated serum citrulline levels in facilitating antibody response against MOG. Other pathways that can be investigated in CTLN1 include lymphocytic responses against neural antigens or any direct effects of citrulline on neural tissue.

TU22. SPATIOTEMPORAL MODULARITY OF GWAS GENES (STGWAS) IDENTIFIED DISTINCT EFFECT OF PRENATAL AND POSTNATAL BRAIN EXPRESSION ACROSS 20 BRAIN DISORDERS AND ANTHROPOMETRIC SOCIAL TRAITS

To report the clinical presentation of a relapse in a patient with MOG antibody disease who had been relapse free for over 20 years.The patient was evaluated in the Providence MS Center.The patient had history of two episodes of optic neuritis in the 1990s. Although clinically stable in 2019, her serum anti-MOG titer was positive, 1:1000. Treatment was not offered since she had remained clinically stable for over 20 years. However, in February 2021 she acutely developed diplopia, right upper extremity sensory disturbance, and ataxia. MR imaging revealed enhancing lesions in the brainstem and cervical spinal cord. Repeat testing for anti-MOG antibodies was positive, 1:10,000.A high anti-MOG antibody titer, at a time when the patient was clinically stable, may have been of prognostic significance. This raises the question of whether initiating treatment solely in response to an elevated titer may have prevented her recent relapse. This case raises the question of whether prospectively monitoring anti-MOG IgG levels in clinically and radiographically stable patients is needed, and if elevated titers are present should treatment be initiated. We believe these issues warrant further prospective investigation in a larger patient cohort.

Polydimethylsiloxane (PDMS) microfluidic modifications for cell-based immunofluorescence assay

Polydimethylsiloxane (PDMS) is a hydrophobic elastomer commonly used for microfluidic fabrication. PDMS has to be modified to improve its hydrophilicity and thus inhibits non-specific protein adsorption. This work evaluates the modification materials for the development of microfluidic cell-based immunofluorescence (IF) assay. In cell-based IF assay, PDMS is modified not just to inhibit the adsorption of non-specific florescent-conjugated protein that causes the elevation of background signal, but also to firmly support cell adhesion for subsequent immunostaining procedure. PDMS materials modified by three regular modification materials consisting of an extracellular matrix (poly-L-lysine; PLL), a hydrophilic polymer (polyvinyl alcohol; PVA) and a non- ionic surfactant (pluronic F127) were compared with each other based on hydrophilicity improvement, minimization of non-specific background signal, and enhancement of human embryonic kidney (HEK) cell adhesion. Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) analysis confirms that all modification materials are successfully immobilized on the PDMS surfaces. Due to its antifouling mechanism, pluronic modification greatly improves the hydrophilicity of the PDMS and inhibits non-specific protein adsorption. Even though the hydrophilicity and non-specific protein adsorption resistivity of the PDMS modified with PLL did not significantly differ from those of the unmodified PDMS, PLL modification obviously promotes HEK cell adhesion. Negative control and Myelin Oligodendrocyte Glycoprotein (MOG) expressing HEK cells were immobilized in microfluidics for IF assay evaluation. Results demonstrate that positive MOG expressing cells can be selectively stained by anti-MOG IgG antibody within 1 h at room temperature. Microfluidic platforms also enhance immobilized cell distribution, which compatibly supports single-cell analysis technique.

Deciphering anti-MOG IgG antibodies: Clinical and radiological spectrum, and comparison of antibody detection assays

IgG antibodies to myelin oligodendrocyte glycoprotein (MOG) detected by cell based assays (CBA) have been identified in a constantly expanding spectrum of CNS demyelinating disorders. However, a universally accepted CBA has not been adopted yet. We aimed to analyze the clinical and radiological features of patients with anti-MOG IgG1-antibodies detected with a live-cell CBA and to compare the three most popular MOG-CBAs. We screened sera from 1300 Greek patients (including 426 patients referred by our 8 clinics) suspected for anti-MOG syndrome, and 120 controls with the live-cell MOG-CBA for IgG1-antibodies. 41 patients, versus 0 controls were seropositive. Clinical, serological and radiological data were available and analyzed for the 21 seropositive patients out of the 426 patients of our clinics. Their phenotypes were: 8 optic neuritis, 3 myelitis, 3 neuromyelitis optica, 2 encephalomyelitis, 2 autoimmune encephalitis and 3 atypical MS. We then retested all sera of our 426 patients with the other two most popular MOG-CBAs for total IgG (a live-cell and a commercial fixed-cell CBAs). Seven IgG1-seropositive patients were seronegative for one or both IgG-CBAs. Yet, all 21 patients had clinical and radiological findings previously described in MOG-antibody associated demyelination disease supporting the high specificity of the IgG1-CBA. In addition, all IgG1-CBA-negative sera were also negative by the IgG-CBAs. Also, all controls were negative by all three assays, except one serum found positive by the live IgG-CBA. Overall, our findings support the wide spectrum of anti-MOG associated demyelinating disorders and the superiority of the MOG-IgG1 CBA over other MOG-CBAs.

Intradermal vaccination prevents anti-MOG autoimmune encephalomyelitis in macaques.

BackgroundAutoimmune demyelinating diseases (ADD) are a major cause of neurological disability due to autoreactive cellular and humoral immune responses against brain antigens. A cure for chronic ADD could be obtained by appropriate immunomodulation.MethodsWe implemented a preclinical scheme to foster immune tolerance to myelin oligodendrocyte glycoprotein (MOG), in a cynomolgus-macaque model of experimental autoimmune encephalomyelitis (EAE), in which administration of recombinant human MOG (rhMOG) elicits brain inflammation mediated by MOG-autoreactive CD4+ lymphocytes and anti-MOG IgG. For immunotherapy, we used a recombinant antibody (Ab) directed against the dendritic cell-asialoglycoprotein receptor (DC-ASGPR) fused either to MOG or a control antigen PSA (prostate-specific antigen).FindingsrhMOG and the anti-DC-ASGPR-MOG were respectively detected in CD1a+ DCs or CD163+ cells in the skin of macaques. Intradermal administration of anti-DC-ASGPR-MOG, but not control anti-DC-ASGPR-PSA, was protective against EAE. The treatment prevented the CD4+ T cell activation and proinflammatory cytokine production observed in controls. Moreover, the administration of anti-DC-ASGPR-MOG induced MOG-specific CD4+CD25+FOXP3+CD39+ regulatory lymphocytes and favoured an upsurge in systemic TGFβ and IL-8 upon rhMOG re-administration in vivo.InterpretationWe show that the delivery of an anti-DC-ASGPR-MOG allows antigen-specific adaptive immune modulation to prevent the breach of immune tolerance to MOG. Our findings pave the way for therapeutic vaccines for long-lasting remission to grave encephalomyelitis with identified autoantigens, such as ADD associated with anti-MOG autoantibodies.FundWork supported by the French ANR (ANR-11-INBS-0008 and ANR-10-EQPX-02-01), NIH (NIH 1 R01 AI 105066), the Baylor Scott and White Healthcare System funding and Roche Research Collaborative grants.

Should Spinal MRI Be Routinely Performed in Patients With Clinically Isolated Optic Neuritis?

Should Spinal MRI Be Routinely Performed in Patients With Clinically Isolated Optic Neuritis?

Retrospective analysis of children with myelin oligodendrocyte glycoprotein antibody-related disorders

BackgroundKnowledge has been expanding on myelin oligodendrocyte glycoprotein (MOG) antibody-associated central nervous system disorders. We delineate the clinical and paraclinical findings and outcome of our pediatric patients with MOG antibody seropositive disease. MethodsWe retrospectively analyzed the clinical presentation, cerebrospinal fluid findings, magnetic resonance imaging (MRI) studies, course and outcome of children seropositive for anti-MOG IgG. ResultsTotal 20 children with neurological symptoms and serum anti-MOG IgG were identified from six centers in Turkey. Median age at onset was 9 years (mean 8.8 ± 5.0 years, range: 1.5–16.5 years). Final diagnoses were acute disseminated encephalomyelitis (ADEM) (n = 5), ADEM + optic neuritis (n = 4), neuromyelitis optica spectrum disorder (NMOSD) (n = 3), myelitis (n = 2), relapsing optic neuritis (n = 2), multiphasic DEM (n = 3), and unclassified relapsing demyelinating disease (n = 1). Seven/20 (35%) children experienced a single episode while 13/20 (65%) had a least one relapse during follow-up. On MRI, subcortical white matter, brainstem, and corpus callosum were preferentially involved regions. Full recovery was observed in 15/20 (75%) children. ConclusionMOG autoimmunity in children has a wide clinical spectrum, tendency to relapse, and a favourable outcome compared with other relapsing demyelinating diseases.

Autoantibodies against myelin sheath and S100β are associated with cognitive dysfunction in patients with rheumatoid arthritis.

Rheumatoid arthritis (RA) has been associated with cognitive impairment and peripheral production of autoantibodies. Autoantibodies against central nervous system (CNS) proteins and S100 calcium-binding β (S100β) were found increased in diseases characterized by cognitive impairment like Alzheimer disease and Neuropsychiatric Systemic Lupus Erythematosus (NPSLE). The aim of this study was to investigate the plasma levels of autoantibodies against myelin basic protein (anti-MBP), myelin oligodendrocyte glycoprotein (anti-MOG) and S100β, and their relationships with cognitive performance in RA patients. Twenty patients with active rheumatoid arthritis and 19 age-, sex-, and schooling-matched healthy controls were recruited. Multiple dimensions of cognitive function were evaluated by structured clinical questionnaires. Autoantibodies and S100β levels were assessed by ELISAs. Patients had significantly higher levels of anti-MBP IgG (17.51±1.36 vs. 5.24±0.53ng/mL), anti-MOG IgG (5.68±1.34 vs. 0.51±0.49ng/mL), and S100β protein (2.24±0.50 vs. 0.47±0.06) than controls (all p<0.0001). After adjusting for potential confounders, RA group presented worse cognitive performance involving the working memory and executive functions such as inhibition, flexibility, and mental control in parallel to higher autoantibodies and S100β levels than healthy controls (all p<0.001). Levels of anti-MBP were negatively associated with delayed verbal recall (DVR; r=-0.42, p=0.005), Stroop Color-Word (r=-0.48, p=0.004), and N-Back Total scores (r=-0.59, p<0.0001) and positively with Trail Making Test B (TMB, r=0.53, p=0.001). Negative correlation was found between levels of anti-MOG and DVR (r=-0.64, p<0.0001), N-Back Total scores (r=-0.35, p=0.03), Stroop Color-Word (r=-0.51, p=0.001), and positively with TMB (r=0.50, p=0.003). S100β levels were associated with DVR (r=-0.51, p=0.002), TMB (r=0.46, p=0.008), Stroop Color-Word (r=-0.67, p<0.0001), and N-Back Total (r=-0.52, p=0.003). RA is associated with impaired cognitive performance associated with higher levels of CNS-related autoantibodies and S100β levels. Given the importance of myelin integrity to cognition, our data indicate that these autoantibodies may be harmful to proper cognitive function.

Change in autoantibody and cytokine responses during the evolution of neuromyelitis optica in patients with systemic lupus erythematosus: A preliminary study

Background: Neuromyelitis optica (NMO)–systemic lupus erythematosus (SLE) association is a rare condition characterized by multiple autoantibodies. Objective: To examine if, during the evolution of NMO, anti-AQP4 responses are part of polyclonal B cell activation, and if T cell responses contribute. Methods: In 19 samples of six patients who developed NMO during SLE, we examined the correlation of AQP4-IgG1 and IgM with (i) anti-MOG IgG and IgM, (ii) anti-nuclear, anti-nucleosome and anti-dsDNA IgG antibodies, (iii) cytokines and chemokines in the serum and (iv) longitudinal relation to NMO relapses/remission. Results: AQP4-IgG1 was present 1–2–5 years before the first NMO relapse. During relapse, AQP4-IgG1, ANA, anti-dsDNA and anti-nucleosome antibodies were elevated. Anti-MOG IgG/IgM and AQP4-IgM antibodies were not detected. AQP4-IgG1 antibodies correlated with concentration of anti-nucleosome, IFN-γ,interferon-gamma-induced CCL10/IP-10 and CCL17/TARC (p<0.05, respectively). CCL17/TARC correlated with levels of anti-nucleosome and anti-dsDNA (p<0.05, respectively). Compared to healthy subjects, concentration of IFN-γ and CCL17/TARC was higher in NMO/SLE (p<0.05). Conclusions: AQP4-IgG1 antibodies are present in the sera years before the first NMO attack in patients with SLE; elevation of anti-AQP4 is part of a polyclonal B cell response during NMO relapses; in spite of multiple autoantibodies in the serum, MOG antibodies were not present; Th1 responses accompany autoantibody responses in NMO/SLE.

Infectious Mononucleosis Triggers Generation of IgG Auto-Antibodies against Native Myelin Oligodendrocyte Glycoprotein.

A history of infectious mononucleosis (IM), symptomatic primary infection with the Epstein Barr virus, is associated with the development of autoimmune diseases and increases the risk to develop multiple sclerosis. Here, we hypothesized that immune activation during IM triggers autoreactive immune responses. Antibody responses towards cellular antigens using a HEp-2 based indirect immunofluorescence assay and native myelin oligodendrocyte glycoprotein (MOG) using a flow cytometry-based assay were determined in 35 patients with IM and in 23 control subjects. We detected frequent immunoglobulin M (IgM) reactivity to vimentin, a major constituent of the intermediate filament family of proteins, in IM patients (27/35; 77%) but rarely in control subjects (2/23; 9%). IgG autoantibodies binding to HEp-2 cells were absent in both groups. In contrast, IgG responses to native MOG, present in up to 40% of children with inflammatory demyelinating diseases of the central nervous system (CNS), were detectable in 7/35 (20%) patients with IM but not in control subjects. Normalization of anti-vimentin IgM levels to increased total IgM concentrations during IM resulted in loss of significant differences for anti-vimentin IgM titers. Anti-MOG specific IgG responses were still detectable in a subset of three out of 35 patients with IM (9%), even after normalization to increased total IgG levels. Vimentin-specific IgM and MOG-specific IgG responses decreased following clinical resolution of acute IM symptoms. We conclude from our data that MOG-specific memory B cells are activated in subset of patients with IM.

Distinction and Temporal Stability of Conformational Epitopes on Myelin Oligodendrocyte Glycoprotein Recognized by Patients with Different Inflammatory Central Nervous System Diseases

Autoantibodies targeting conformationally intact myelin oligodendrocyte glycoprotein (MOG) are found in different inflammatory diseases of the CNS, but their antigenic epitopes have not been mapped. We expressed mutants of MOG on human HeLa cells and analyzed sera from 111 patients (104 children, 7 adults) who recognized cell-bound human MOG, but had different diseases, including acute disseminated encephalomyelitis (ADEM), one episode of transverse myelitis or optic neuritis, multiple sclerosis (MS), anti-aquaporin-4 (AQP4)-negative neuromyelitis optica (NMO), and chronic relapsing inflammatory optic neuritis (CRION). We obtained insight into the recognition of epitopes in 98 patients. All epitopes identified were located at loops connecting the β strands of MOG. The most frequently recognized MOG epitope was revealed by the P42S mutation positioned in the CC'-loop. Overall, we distinguished seven epitope patterns, including the one mainly recognized by mouse mAbs. In half of the patients, the anti-MOG response was directed to a single epitope. The epitope specificity was not linked to certain disease entities. Longitudinal analysis of 11 patients for up to 5 y indicated constant epitope recognition without evidence for intramolecular epitope spreading. Patients who rapidly lost their anti-MOG IgG still generated a long-lasting IgG response to vaccines, indicating that their loss of anti-MOG reactivity did not reflect a general lack of capacity for long-standing IgG responses. The majority of human anti-MOG Abs did not recognize rodent MOG, which has implications for animal studies. Our findings might assist in future detection of potential mimotopes and pave the way to Ag-specific depletion.

Antibodies to MOG are transient in childhood acute disseminated encephalomyelitis

To study the longitudinal dynamics of anti-myelin oligodendrocyte glycoprotein (MOG) autoantibodies in childhood demyelinating diseases. 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. 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. The persistence or disappearance of antibodies to MOG may have prognostic relevance for acute childhood demyelination.

Conformational epitopes of myelin oligodendrocyte glycoprotein are targets of potentially pathogenic antibody responses in multiple sclerosis

BackgroundMyelin/oligodendrocyte glycoprotein (MOG) is a putative autoantigen in multiple sclerosis (MS). Establishing the pathological relevance and validity of anti-MOG antibodies as biomarkers has yielded conflicting reports mainly due to different MOG isoforms used in different studies. Because epitope specificity may be a key factor determining anti-MOG reactivity we aimed at identifying a priori immunodominant MOG epitopes by monoclonal antibodies (mAbs) and at assessing clinical relevance of these epitopes in MS.MethodsSera of 325 MS patients, 69 patients with clinically isolated syndrome and 164 healthy controls were assayed by quantitative, high-throughput ELISA for reactivity to 3 different MOG isoforms, and quantitative titers correlated with clinical characteristics. mAbs defined unique immunodominant epitopes distinct to each of the isoforms.ResultsIn the majority of human samples anti-MOG levels were skewed towards low titers. However, in 8.2% of samples high-titer anti-MOG antibodies were identified. In contrast to anti-MOG reactivity observed in a mouse model of MS, in patients with MS these never reacted with ubiquitously exposed epitopes. Moreover, in patients with relapsing-remitting MS high-titer anti-MOG IgG correlated with disability (EDSS; Spearman r = 0.574; p = 0.025).ConclusionsThus high-titer reactivity likely represents high-affinity antibodies against pathologically relevant MOG epitopes, that are only present in a small proportion of patients with MS. Our study provides valuable information about requirements of anti-MOG reactivity for being regarded as a prognostic biomarker in a subtype of MS.

Temporal dynamics of anti-MOG antibodies in CNS demyelinating diseases

Recent studies demonstrated the presence of autoantibodies to native myelin oligodendrocyte glycoprotein (MOG) in juvenile patients with acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS). However, so far no longitudinal studies on anti-MOG antibodies have been performed. Therefore, we determined serum and CSF antibodies against native human MOG in 266 pediatric and adult subjects with ADEM, clinically isolated syndrome (CIS), MS, other neurological diseases (OND) and healthy controls (HC) and longitudinal samples of 25 patients with ADEM, CIS, MS and OND using an immunofluorescence assay. We detected serum high-titer MOG IgG in 15/34 (44%) patients with ADEM, but only rarely in CIS (3/38, 8%), MS (2/89, 2%), OND (1/58, 2%) and HC (0/47). Longitudinal analysis of serum anti-MOG IgG showed different temporal dynamics of serum antibody responses in ADEM, CIS and MS and indicated an association of a favorable clinical outcome in ADEM with a decrease in antibody titers over time.

Late B Cell Depletion with a Human Anti-Human CD20 IgG1κ Monoclonal Antibody Halts the Development of Experimental Autoimmune Encephalomyelitis in Marmosets

Depletion of CD20(+) B cells has been related to reduced clinical activity in relapsing-remitting multiple sclerosis. The underlying mechanism is not understood, because serum IgG levels were unaltered by the treatment. We report the effect of late B cell depletion on cellular and humoral immune mechanisms in a preclinical multiple sclerosis model (i.e., experimental autoimmune encephalomyelitis [EAE] in the common marmoset). We used a novel human anti-human CD20 IgG1κ mAb (HuMab 7D8) that cross-reacts with marmoset CD20. EAE was induced in 14 marmosets by immunization with recombinant human myelin oligodendrocyte glycoprotein (MOG) in CFA. After 21 d, B cells were depleted in seven monkeys by HuMab 7D8, and seven control monkeys received PBS. The Ab induced profound and long-lasting B cell depletion from PBMCs and lymphoid organs throughout the observation period of 106 d. Whereas all of the control monkeys developed clinically evident EAE, overt neurologic deficits were reduced substantially in three HuMab 7D8-treated monkeys, and four HuMab 7D8-treated monkeys remained completely asymptomatic. The effect of HuMab 7D8 was confirmed on magnetic resonance images, detecting only small lesions in HuMab 7D8-treated monkeys. The infusion of HuMab 7D8 arrested the progressive increase of anti-MOG IgG Abs. Although CD3(+) T cell numbers in lymphoid organs were increased, their proliferation and cytokine production were impaired significantly. Most notable were the substantially reduced mRNA levels of IL-7 and proinflammatory cytokines (IL-6, IL-17A, IFN-γ, and TNF-α). In conclusion, B cell depletion prevents the development of clinical and pathological signs of EAE, which is associated with impaired activation of MOG-reactive T cells in lymphoid organs.

Antibodies to myelin oligodendrocyte glycoprotein are not involved in the severity of chronic non-remitting experimental autoimmune encephalomyelitis

To elucidate the role of antibodies in development of chronic non-remitting experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice, which is a well-established Th1-mediated autoimmune disease, and the involvement of activation-induced cytidine deaminase (AID) in Th1-mediated function, we have investigated the myelin oligodendrocyte glycoprotein (MOG)-induced EAE in mice deficient of AID, which is absolutely required for class switching and somatic hypermutation. Following immunization with MOG, AID −/− had completely same levels of clinical and pathological severity of EAE when compared with AID +/− and AID +/+, although AID −/− did not produce IgG and anti-MOG IgG. Similar levels of T cell proliferation and a modest increase of anti-MOG IgM synthesis were found in spleen cells of AID −/− stimulated with MOG. These results indicate that antibodies are not involved in development of EAE in C57BL/6 mice.