Elevated intrathecal myelin oligodendrocyte glycoprotein antibodies in multiple sclerosis

Myelin Oligodendrocyte Glycoprotein-Immunoglobulin G in the CSF: Clinical Implication of Testing and Association With Disability

Background and Objective

To investigate the clinical relevance of CSF myelin oligodendrocyte glycoprotein-immunoglobulin G (MOG-IgG) testing in a large multicenter cohort.

Methods

In this multicenter cohort study, paired serum-CSF samples from 474 patients with suspected inflammatory demyelinating disease (IDD) from 11 referral hospitals were included. After serum screening, patients were grouped into seropositive myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD, 31), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG + NMOSD, 60), other IDDs (217), multiple sclerosis (MS, 45), and non-IDDs (121). We then screened CSF for MOG-IgG and compared the clinical and serologic characteristics of patients uniquely positive for MOG-IgG in the CSF to seropositive patients with MOGAD.

Results

Nineteen patients with seropositive MOGAD (61.3%), 9 with other IDDs (CSF MOG + IDD, 4.1%), 4 with MS (8.9%), but none with AQP4-IgG + NMOSD nor with non-IDDs tested positive in the CSF for MOG-IgG. The clinical, pathologic, and prognostic features of patients uniquely positive for CSF MOG-IgG, with a non-MS phenotype, were comparable with those of seropositive MOGAD. Intrathecal MOG-IgG synthesis, observed from the onset of disease, was shown in 12 patients: 4 of 28 who were seropositive and 8 who were uniquely CSF positive, all of whom had involvement of either brain or spinal cord. Both CSF MOG-IgG titer and corrected CSF/serum MOG-IgG index, but not serum MOG-IgG titer, were associated with disability, CSF pleocytosis, and level of CSF proteins.

Discussion

CSF MOG-IgG is found in IDD other than MS and also in MS. In IDD other than MS, the CSF MOG-IgG positivity can support the diagnosis of MOGAD. The synthesis of MOG-IgG in the CNS of patients with MOGAD can be detected from the onset of the disease and is associated with the severity of the disease.

Classification of Evidence

This study provides Class II evidence that the presence of CSF MOG-IgG can improve the diagnosis of MOGAD in the absence of an MS phenotype, and intrathecal synthesis of MOG-IgG was associated with increased disability.

Fulminating Autoimmune Demyelination with Optic Neuropathy in a Case of Pediatric Cerebral Adrenoleukodystrophy: Case Report and Review of the Literature

X-linked adrenoleukodystrophy (ALD) is a leukodystrophy characterized not only by progressive loss of myelin in the central nervous system due to dysmyelination, but also by acute, subacute, or chronic inflammatory demyelination. This results in the phenotypic variability of cerebral ALD (cerALD), which is independent of the genotype. In this article, we reported a fulminant presentation with fluctuating encephalopathy and visual loss in a patient with childhood onset cerALD. Brain MRI showed symmetric confluent occipito-temporal demyelination with severe disruption of the blood–brain barrier and prechiasmal optic neuropathy. The patient's cerebral spinal fluid (CSF) demonstrated an elevated IgG index, myelin basic proteins, and oligoclonal bands. Within 48 hours of receiving immunomodulating therapy, the patient's symptoms of psychomotor slowing, visual impairment, and areflexia partially resolved. High plasma C26:0 levels and high ratios of C24/22 and C26/22 were diagnostic of ALD. It has been shown that environmental factors play an important role in the inflammatory demyelination responsible for the severe phenotypes of cerALD.

Difference in the Source of Anti-AQP4-IgG and Anti-MOG-IgG Antibodies in CSF in Patients With Neuromyelitis Optica Spectrum Disorder

Objective

To elucidate the differences in the source and in the level of intrathecal synthesis between anti–aquaporin-4 antibodies (AQP4-IgG) and anti-myelin oligodendrocyte glycoprotein antibodies (MOG-IgG).

Methods

Thirty-eight patients with MOG-IgG–associated disease and 36 with AQP4-IgG–positive neuromyelitis optica spectrum disorders (NMOSD) were studied for the antibody titers in the sera and CSF simultaneously collected in the acute attacks. The quotients between CSF and serum levels of albumin, total immunoglobulin G, and each disease-specific antibody were calculated. Intrathecal production level in each disease-specific antibody was evaluated by calculating the antibody index from these quotients.

Results

Eleven of the 38 patients with MOG-IgG were positive for the antibody only in the CSF, while no patient with AQP4-IgG showed CSF-restricted AQP4-IgG. Blood-brain barrier compromise as shown by raised albumin quotients was seen in 75.0% of MOG-IgG–positive cases and 43.8% of AQP4-IgG–positive cases. Moreover, MOG-IgG quotients were >10 times higher than AQP4-IgG quotients (effect size r = 0.659, p < 0.0001). Elevated antibody index (>4.0) was confirmed in 12 of 21 with MOG-IgG, whereas it was seen only in 1 of 16 with AQP4-IgG (φ = 0.528, p < 0.0001). The CSF MOG-IgG titers (ρ = 0.519, p = 0.001) and antibody indexes for MOG-IgG (ρ = 0.472, p = 0.036) correlated with the CSF cell counts but not with clinical disability.

Conclusions

Intrathecal production of MOG-IgG may occur more frequently than that of AQP4-IgG. This finding implies the different properties of B-cell trafficking and antibody production between MOG-IgG–associated disease and AQP4-IgG–positive NMOSD.

Diagnosis and Treatment of NMO Spectrum Disorder and MOG-Encephalomyelitis

Neuromyelitis optica spectrum disorders (NMOSD) are autoantibody mediated chronic inflammatory diseases. Serum antibodies (Abs) against the aquaporin-4 water channel lead to recurrent attacks of optic neuritis, myelitis and/or brainstem syndromes. In some patients with symptoms of NMOSD, no AQP4-Abs but Abs against myelin-oligodendrocyte-glycoprotein (MOG) are detectable. These clinical syndromes are now frequently referred to as "MOG-encephalomyelitis" (MOG-EM). Here we give an overview on current recommendations concerning diagnosis of NMOSD and MOG-EM. These include antibody and further laboratory testing, MR imaging and optical coherence tomography. We discuss therapeutic options of acute attacks as well as longterm immunosuppressive treatment, including azathioprine, rituximab, and immunoglobulins.

Anti-myelin oligodendrocyte glycoprotein antibodies: Magnetic resonance imaging findings in a case series and a literature review

Myelin oligodendrocyte glycoprotein is a protein exclusively expressed on the surface of oligodendrocytes and myelin in the central nervous system. Antibodies against myelin oligodendrocyte glycoprotein were initially detected in children with demyelinating syndromes, and more recently reported in a broad spectrum of central nervous system demyelinating diseases in adults, including neuromyelitis optica spectrum disorders and bilateral optic neuritis. Patients with myelin oligodendrocyte glycoprotein antibody-associated demyelination appear to have unique clinical and radiological features. To the best of our knowledge a series of Italian patients with optic neuritis and positivity to myelin oligodendrocyte glycoprotein antibodies has not yet been reported and the paper on myelin oligodendrocyte glycoprotein antibodies are more focused on clinical features, diagnosis and outcome than on the radiological appearance, so we want to retrospectively report magnetic resonance imaging features of a group of eight patients, who came to our Ophthalmologic Emergency Department for optic neuritis and were found seropositive for myelin oligodendrocyte glycoprotein antibodies, comparing our data with the findings described in the literature.

Diversity of immune cell types in multiple sclerosis and its animal model: Pathological and therapeutic implications

Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system with an autoimmune attack on the components of the myelin sheath and axons. The etiology of the disease remains largely unknown, but it is commonly acknowledged that the development of MS probably results from the interaction of environmental factors in conjunction with a genetic predisposition. Current therapeutic approaches can only ameliorate the clinical symptoms or reduce the frequency of relapse in MS. Most drugs used in this disease broadly suppress the functions of immune effector cells, which can result in serious side effects. Thus, new therapeutic methods resulting in greater efficacy and lower toxicity are needed. Toward this end, cell-based therapies are of increasing interest in the treatment of MS. Several immunoregulatory cell types, including regulatory T cells, regulatory B cells, M2 macrophages, tolerogenic dendritic cells, and stem cells, have been developed as novel therapeutic tools for the treatment of MS. In this Review, we summarize studies on the application of these cell populations for the treatment of MS and its animal model, experimental autoimmune encephalomyelitis, and call for further research on applications and mechanisms by which these cells act in the treatment of MS. © 2017 The Authors Journal of Neuroscience Research Published by Wiley Periodicals, Inc.

[Current concepts on intrathecal humoral immune response and diagnostic importance of oligoclonal immunoglobulins in multiple sclerosis]

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system of probable autoimmune origin. In this review of literature, the authors present a constantly broadening list of potential antigens, including myelin and non-myelin structures, that cause the autoimmune reaction. Determination of antibodies to any antigen has not sufficient specificity and sensitivity for the use in routine laboratory practice. Oligoclonal immunoglobulins determined with isoelectric focusing (IEF) technique are currently considered as the main immunological MS markers. The sensitivity and specificity of IEF are 90 and 86%, respectively. The authors have considered the additional markers such as oligoclonal IgM and MRZ-response.

Antigen Presentation, Autoantigens, and Immune Regulation in Multiple Sclerosis and Other Autoimmune Diseases

Antigen presentation is in the center of the immune system, both in host defense against pathogens, but also when the system is unbalanced and autoimmune diseases like multiple sclerosis (MS) develop. It is not just by chance that a major histocompatibility complex gene is the major genetic susceptibility locus in MS; a feature that MS shares with other autoimmune diseases. The exact etiology of the disease, however, has not been fully understood yet. T cells are regarded as the major players in the disease, but most probably a complex interplay of altered central and peripheral tolerance mechanisms, T-cell and B-cell functions, characteristics of putative autoantigens, and a possible interference of environmental factors like microorganisms are at work. In this review, new data on all these different aspects of antigen presentation and their role in MS will be discussed, probable autoantigens will be summarized, and comparisons to other autoimmune diseases will be drawn.

The role of immune cells, glia and neurons in white and gray matter pathology in multiple sclerosis

Multiple sclerosis is one of the most common causes of chronic neurological disability beginning in early to middle adult life. Multiple sclerosis is idiopathic in nature, yet increasing correlative evidence supports a strong association between one's genetic predisposition, the environment and the immune system. Symptoms of multiple sclerosis have primarily been shown to result from a disruption in the integrity of myelinated tracts within the white matter of the central nervous system. However, recent research has also highlighted the hitherto underappreciated involvement of gray matter in multiple sclerosis disease pathophysiology, which may be especially relevant when considering the accumulation of irreversible damage and progressive disability. This review aims at providing a comprehensive overview of the interplay between inflammation, glial/neuronal damage and regeneration throughout the course of multiple sclerosis via the analysis of both white and gray matter lesional pathology. Further, we describe the common pathological mechanisms underlying both relapsing and progressive forms of multiple sclerosis, and analyze how current (as well as future) treatments may interact and/or interfere with its pathology. Understanding the putative mechanisms that drive disease pathogenesis will be key in helping to develop effective therapeutic strategies to prevent, mitigate, and treat the diverse morbidities associated with multiple sclerosis.

MOG cell-based assay detects non-MS patients with inflammatory neurologic disease

Objective:

To optimize sensitivity and disease specificity of a myelin oligodendrocyte glycoprotein (MOG) antibody assay.

Methods:

Consecutive sera (n = 1,109) sent for aquaporin-4 (AQP4) antibody testing were screened for MOG antibodies (Abs) by cell-based assays using either full-length human MOG (FL-MOG) or the short-length form (SL-MOG). The Abs were initially detected by Alexa Fluor goat anti-human IgG (H + L) and subsequently by Alexa Fluor mouse antibodies to human IgG1.

Results:

When tested at 1:20 dilution, 40/1,109 sera were positive for AQP4-Abs, 21 for SL-MOG, and 180 for FL-MOG. Only one of the 40 AQP4-Ab–positive sera was positive for SL-MOG-Abs, but 10 (25%) were positive for FL-MOG-Abs (p = 0.0069). Of equal concern, 48% (42/88) of sera from controls (patients with epilepsy) were positive by FL-MOG assay. However, using an IgG1-specific secondary antibody, only 65/1,109 (5.8%) sera were positive on FL-MOG, and AQP4-Ab– positive and control sera were negative. IgM reactivity accounted for the remaining anti-human IgG (H + L) positivity toward FL-MOG. The clinical diagnoses were obtained in 33 FL-MOG–positive patients, blinded to the antibody data. IgG1-Abs to FL-MOG were associated with optic neuritis (n = 11), AQP4-seronegative neuromyelitis optica spectrum disorder (n = 4), and acute disseminated encephalomyelitis (n = 1). All 7 patients with probable multiple sclerosis (MS) were MOG-IgG1 negative.

Conclusions:

The limited disease specificity of FL-MOG-Abs identified using Alexa Fluor goat anti-human IgG (H + L) is due in part to detection of IgM-Abs. Use of the FL-MOG and restricting to IgG1-Abs substantially improves specificity for non-MS demyelinating diseases.

Classification of evidence:

This study provides Class II evidence that the presence of serum IgG1- MOG-Abs in AQP4-Ab–negative patients distinguishes non-MS CNS demyelinating disorders from MS (sensitivity 24%, 95% confidence interval [CI] 9%–45%; specificity 100%, 95% CI 88%–100%).

Evaluation of the humoral response against mycobacterial peptides, homologous to MOG₃₅₋₅₅, in multiple sclerosis patients

Bacillus Calmette-Guérin (BCG) and Mycobacterium avium subspecies paratuberculosis (MAP) have been associated with multiple sclerosis (MS). Clinical data indicates that BCG vaccination exerts anti-inflammatory effects in MS; conversely, MAP is thought to be one of the possible infectious factors responsible of MS through a molecular mimicry mechanism. A peptide-based indirect ELISA was used to detect antibodies against the encephalitogenic myelin oligodendrocyte glycoprotein (MOG)35-55 epitope, and two mycobacterial peptides sharing sequence homology with the latter: MAP_2619c352-361/BCG_1224355-364 and BCG_3329c64-74. Among 40 MS patients and 39 healthy volunteers included in the study, only MOG35-55 was capable of inducing a significantly higher humoral response in MS subjects compared to controls. Indeed, 11 out of 40 MS subjects (27.5%) and only 2 out of 39 controls (5%) were antibody-positive for MOG35-55 (p=0.01, AUC=0.65). These findings strengthen the importance of MOG35-55 in MS pathogenesis. The MAP and BCG MOG-homologues epitopes investigated were not recognized in MS patients. Overall, the results allow us concluding that sharing homology of linear epitopes is necessary but not sufficient to induce antibody-mediated cross-reactivity.

Antimyelin antibodies as predictors of disability after clinically isolated syndrome

There is controversy whether determination of antibodies against myelin, myelin oligodendrocyte glycoprotein, and myelin basic protein in serum from patients with a first episode suggestive of multiple sclerosis is of prognostic value. We evaluated whether detection of antimyelin antibodies in serum indicates a worse course with earlier time to a second relapse and increased progression of disability. We conducted a prospective study at the Department of Neurology, Inselspital Bern, Switzerland from 2004 to 2008 in patients presenting with a clinically isolated syndrome (CIS) and a follow-up of at least 4 months. Antimyelin antibodies were assessed by Western blot. Results were correlated with clinical course and sex. Among 93 consecutive patients with a CIS, 74 (80%) were positive for either one or both antimyelin antibodies. A relapse occurred in 49 (53%) and the median EDSS was 2 (range 1-3.5) after a mean observation period of 20 months. Presence of antimyelin antibodies at CIS neither increased the risk for a second relapse nor for progression of disability. Stratification for gender did not reveal differences for any of the clinical surrogates. The sole determination of antimyelin antibodies in serum is of limited prognostic value for the identification of patients with different short-term course.

Protein array-based profiling of CSF identifies RBPJ as an autoantigen in multiple sclerosis

OBJECTIVE

To profile the reactivity of CSF-derived immunoglobulin from patients with multiple sclerosis (MS) against a large panel of antigens, to identify disease-specific reactivities.

METHODS

CSF from subjects with MS with elevated immunoglobulin G and CSF from control subjects presenting with other inflammatory neurologic disease were screened against a protein array consisting of 9,393 proteins. Reactivity to a candidate protein identified using these arrays was confirmed with ELISA and immunocytochemistry.

RESULTS

Autoantibodies against one protein on the array, recombination signal binding protein for immunoglobulin kappa J region (RBPJ), discriminated between patients with MS and controls (p = 0.0052). Using a large validation cohort, we found a higher prevalence of autoantibodies against RBPJ in the CSF of patients with MS (12.5%) compared with the CSF of patients with other neurologic diseases (1.6%; p = 0.02) by ELISA. This difference in reactivity was restricted to the CSF as serum reactivity against RBPJ did not differ between patients and controls. The presence of CSF autoantibodies against RBPJ was further confirmed by immunocytochemistry.

CONCLUSIONS

These data indicate that RBPJ, a ubiquitous protein of the Notch signaling pathway that plays an important role in Epstein-Barr virus infection, is a novel MS autoantigen candidate that is recognized by CSF-derived immunoglobulin G in a subset of patients with MS.

Intrathecal oligoclonal IgG synthesis in multiple sclerosis

The diagnosis of multiple sclerosis is based on dissemination in time and space. Before 2010 lack of evidence for dissemination in space could be substituted by a paraclinical test, cerebrospinal fluid (CSF) oligoclonal bands (OCBs). The present meta-analysis (13,467 patients) shows that the diagnostic specificity of OCB drops from 94% to 61% if inflammatory etiologies are considered. Importantly, this was not caused by poor laboratory practice. This review on CSF OCB further illustrates the conceptional problem of substituting dissemination in space with a biomarker. The potential prognostic value of intrathecal OCB will need to be tested prospectively.

Serum autoantibodies to myelin peptides distinguish acute disseminated encephalomyelitis from relapsing-remitting multiple sclerosis

BACKGROUND AND OBJECTIVE

Acute disseminated encephalomyelitis (ADEM) and relapsing-remitting multiple sclerosis (RRMS) share overlapping clinical, radiologic and laboratory features at onset. Because autoantibodies may contribute to the pathogenesis of both diseases, we sought to identify autoantibody biomarkers that are capable of distinguishing them.

METHODS

We used custom antigen arrays to profile anti-myelin-peptide autoantibodies in sera derived from individuals with pediatric ADEM (n = 15), pediatric multiple sclerosis (Ped MS; n = 11) and adult MS (n = 15). Using isotype-specific secondary antibodies, we profiled both IgG and IgM reactivities. We used Statistical Analysis of Microarrays software to confirm the differences in autoantibody reactivity profiles between ADEM and MS samples. We used Prediction Analysis of Microarrays software to generate and validate prediction algorithms, based on the autoantibody reactivity profiles.

RESULTS

ADEM was characterized by IgG autoantibodies targeting epitopes derived from myelin basic protein, proteolipid protein, myelin-associated oligodendrocyte basic glycoprotein, and alpha-B-crystallin. In contrast, MS was characterized by IgM autoantibodies targeting myelin basic protein, proteolipid protein, myelin-associated oligodendrocyte basic glycoprotein and oligodendrocyte-specific protein. We generated and validated prediction algorithms that distinguish ADEM serum (sensitivity 62-86%; specificity 56-79%) from MS serum (sensitivity 40-87%; specificity 62-86%) on the basis of combined IgG and IgM anti-myelin autoantibody reactivity to a small number of myelin peptides.

CONCLUSIONS

Combined profiles of serum IgG and IgM autoantibodies identified myelin antigens that may be useful for distinguishing MS from ADEM. Further studies are required to establish clinical utility. Further biological assays are required to delineate the pathogenic potential of these antibodies.

Biomarkers in Multiple Sclerosis: An Up-to-Date Overview

During the last decades, the effort of establishing satisfactory biomarkers for multiple sclerosis has been proven to be very difficult, due to the clinical and pathophysiological complexities of the disease. Recent knowledge acquired in the domains of genomics-immunogenetics and neuroimmunology, as well as the evolution in neuroimaging, has provided a whole new list of biomarkers. This variety, though, leads inevitably to confusion in the effort of decision making concerning strategic and individualized therapeutics. In this paper, our primary goal is to provide the reader with a list of the most important characteristics that a biomarker must possess in order to be considered as reliable. Additionally, up-to-date biomarkers are further divided into three subgroups, genetic-immunogenetic, laboratorial, and imaging. The most important representatives of each category are presented in the text and for the first time in a summarizing workable table, in a critical way, estimating their diagnostic potential and their efficacy to correlate with phenotypical expression, neuroinflammation, neurodegeneration, disability, and therapeutical response. Special attention is given to the "gold standards" of each category, like HLA-DRB1∗ polymorphisms, oligoclonal bands, vitamin D, and conventional and nonconventional imaging techniques. Moreover, not adequately established but quite promising, recently characterized biomarkers, like TOB-1 polymorphisms, are further discussed.

Glycoproteins as targets of autoantibodies in CNS inflammation: MOG and more

B cells and antibodies constitute an important element in different inflammatory diseases of the central nervous system (CNS). Autoantibodies can serve as a biomarker to identify disease subgroups and may in addition contribute to the pathogenic process. One candidate autoantigen for multiple sclerosis (MS) is myelin oligodendrocyte glycoprotein (MOG). MOG is localized at the outermost surface of myelin in the CNS and has been the focus of extensive research for more than 30 years. Its role as an important autoantigen for T cells and as a target of demyelinating autoantibodies has been established in several variants of experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The literature regarding antibodies to MOG in MS patients is confusing and contradictory. Recent studies, however, have described high levels of antibodies to conformationally correct MOG in pediatric acquired demyelination, both acute disseminated encephalomyelitis (ADEM) and MS. In adult MS, such antibodies are rarely found and then only at low levels. In this review, we summarize key findings from animal models and patient studies, discuss challenges in detecting anti-MOG antibodies in patients and present recent approaches to identifying new autoantigens in MS.

Antigen microarrays identify CNS-produced autoantibodies in RRMS

OBJECTIVE

Multiple sclerosis (MS) is characterized by the local production of antibodies in the CNS and the presence of oligoclonal bands in the CSF. Antigen arrays allow the study of antibody reactivity against a large number of antigens using small volumes of fluid with greater sensitivity than ELISA. We investigated whether there were unique autoantibodies in the CSF of patients with MS as measured by antigen arrays and whether these antibodies differed from those in serum.

METHODS

We used antigen arrays to analyze the reactivity of antibodies in matched serum and CSF samples of 20 patients with untreated relapsing-remitting MS (RRMS), 26 methylprednisolone-treated patients with RRMS, and 20 control patients with other noninflammatory neurologic conditions (ONDs) against 334 different antigens including heat shock proteins, lipids, and myelin antigens.

RESULTS

We found different antibody signatures in matched CSF and serum samples The targets of these antibodies included epitopes of the myelin antigens CNP, MBP, MOBP, MOG, and PLP (59%), HSP60 and HSP70 (38%), and the 68-kD neurofilament (3%). The antibody response in patients with MS was heterogeneous; CSF antibodies in individual patients reacted with different autoantigens. These autoantibodies were locally synthesized in the CNS and were of the immunoglobulin G class. Finally, we found that treatment with steroids decreased autoantibody reactivity, epitope spreading, and intrathecal autoantibody synthesis.

CONCLUSIONS

These studies provide a new avenue to investigate the local antibody response in the CNS, which may serve as a biomarker to monitor both disease progression and response to therapy in MS.