Autoantibodies In Multiple Sclerosis Research Articles

Antibodies against the flotillin-1/2 complex in patients with multiple sclerosis.

Multiple sclerosis is a tissue-specific autoimmune disease of the central nervous system in which the antigen(s) remains elusive. Antibodies targeting the flotillin-1/2 complex have been described in 1-2% of the patients in a recent study. Other candidate antigens as anoctamin-2 or neurofascin-155 have been previously described in multiple sclerosis patients, although their clinical relevance remains uncertain. Our study aims to analyse the frequency and clinical relevance of antibodies against neurofascin-155, anoctamin-2 and flotillin-1/2 complex in multiple sclerosis. Serum (n = 252) and CSF (n = 50) samples from 282 multiple sclerosis patients were included in the study. The control group was composed of 260 serum samples (71 healthy donors and 189 with other neuroinflammatory disorders). Anti-flotillin-1/2, anti-anoctamin-2 and anti-neurofascin-155 antibodies were tested by cell-based assays using transfected cells. We identified six multiple sclerosis patients with antibodies against the flotillin-1/2 complex (2.1%) and one multiple sclerosis patient with antibodies against anoctamin-2 (0.35%). All multiple sclerosis patients were negative for anti-neurofascin-155 antibodies. Three of the anti-flotillin-1/2 positive patients showed anti-flotillin-1/2 positivity in other serum samples extracted at different moments of their disease. Immunoglobulin G subclasses of anti-flotillin-1/2 antibodies were predominantly one and three. We confirm that antibodies targeting the flotillin-1/2 complex are present in a subgroup of patients with multiple sclerosis. Further studies are needed to understand the clinical and pathological relevance of anti-flotillin-1/2 autoantibodies in multiple sclerosis.

Editorial introductions.

Current Opinion in Neurology was launched in 1988. It is one of a successful series of review journals whose unique format is designed to provide a systematic and critical assessment of the literature as presented in the many primary journals. The field of neurology is divided into 14 sections that are reviewed once a year. Each section is assigned a Section Editor, a leading authority in the area, who identifies the most important topics at that time. Here we are pleased to introduce the Journal's Section Editors for this issue. SECTION EDITORS Luis QuerolLuis QuerolLuis Querol (Valencia, 1980) graduated in Medicine at the University of Oviedo, Spain, and completed his residency in Neurology at the Santa Creu i Sant Pau Hospital in Barcelona. In 2009, he joined the group of Prof. Isabel Illa where he developed his doctoral thesis on the role of autoantibodies in immune-mediated neuropathies. In 2012, he worked as an associate researcher in the group of Dr Kevin O’Connor, Department of Neurology, Yale University (USA), where he developed projects related to autoantibodies in multiple sclerosis and myasthenia gravis. He completed his PhD in Medicine at the Universidad Autónoma de Barcelona, Spain, in 2013 thanks to studies that identified anti-contactin antibodies in a specific subgroup of patients with CIDP, in what is the first clinically useful marker detected in CIDP. Since then, he has led the auoimmune neurology clinics at Hospital Sant Pau in Barcelona and has continued a fruitful scientific production in the field of autoantibodies and biomarkers in autoimmune neurological disorders. Ichizo NishinoIchizo NishinoDr Ichizo Nishino, FAAN, FANA, is Director of Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP). He obtained his M.D. in 1989 and Ph.D. in 1998 from Kyoto University, Japan. After five years of training in clinical neurology and six years of research fellowship, including two years at Columbia University, he was appointed to his current position in 2001. By now, he has published more than 600 PubMed-listed papers in the field, including the reports of gene discoveries for MNGIE and Danon disease, and the report of a new muscle disease – megaconial congenital muscular dystrophy (OMIM: 602541) whose causative was also later identified by his own group. His laboratory functions as a nationwide referral center for muscle disease, providing diagnostic analyses for muscle pathology and genetic diagnosis. His lab receives around 80% of muscle biopsies performed in Japan (1103 cases in 2021) and he signs out all cases. As a result, more than 22,000 frozen muscle biopsy samples have been accumulated in his muscle repository, which is one of the largest collections of the patient's muscles. Currently, Dr Nishino is a Visiting Professor at six universities: University of Yamanashi (Japan), Shinshu University (Japan), Kaohsiung Medical University (Taiwan), Fu Jen Catholic University (Taiwan), Peking University First Hospital (China), and Siriraj Hospital Mahidol University (Thailand). He is also serving as President of Asian-Oceanian Myology Center and Executive Board member in several societies including World Muscle Society. Albert LudolphAlbert LudolphAlbert Ludolph is currently Professor of Neurology, Chair and Director of the Department of Neurology, University of Ulm, Ulm, Germany and Speaker of the Site Ulm of the German Center for Neurodegenerative diseses (DZNE, Helmholtz Society). He obtained his M.D. from the University of Mainz, Germany, in 1981 and is a boarded neurologist and psychiatrist (education from University of Münster, Germany). His research focusses on translational work in neurodegenerative diseases; his work is mirrored by more than 600 PubMed-listed papers. His specific focus of interests are motor neuron diseases, Huntington's disease and frontotemporal dementias. The Department of Neurology in Ulm is an international referral center in particular for patients with ALS/MND. In the past his research focused on neurotoxicological and neuropharmacological research in humans, but also non-human primates. He was involved and initiated studies of neurogenetics of ALS, of the epidemiology of the disease (established registers in Southern Germany, Egypt and Mongolia), of the definition of the neuroanatomical sequence of events describing ALS and FTD, the development of biomarkers in ALS and FTD and beyond, and several drug trials, including investigator-initiated interventions. In recent years he tried to define the preclinical period of ALS including the role of the hypothalamus and its metabolic consequences.

Pathogenic autoantibodies in multiple sclerosis - from a simple idea to a complex concept.

The role of autoantibodies in multiple sclerosis (MS) has been enigmatic since the first description, many decades ago, of intrathecal immunoglobulin production in people with this condition. Some studies have indicated that MS pathology is heterogeneous, with an antibody-associated subtype - characterized by B cells (in varying quantities), antibodies and complement - existing alongside other subtypes with different pathologies. However, subsequent evidence suggested that some cases originally diagnosed as MS with autoantibody-mediated demyelination were more likely to be neuromyelitis optica spectrum disorder or myelin oligodendrocyte glycoprotein antibody-associated disease. These findings raise the important question of whether an autoantibody-mediated MS subtype exists and whether pathogenic MS-associated autoantibodies remain to be identified. Potential roles of autoantibodies in MS could range from specific antibodies defining the disease to a non-disease-specific amplification of cellular immune responses and other pathophysiological processes. In this Perspective, we review studies that have attempted to identify MS-associated autoantibodies and provide our opinions on their possible roles in the pathophysiology of MS.

Multiple Sclerosis and Autoreactive Antibodies

Background: The prevalence of auto antibodies in multiple sclerosis (MS) patients and their implications differ between various studies. Our aims were to determine the frequency and type of auto reactive antibodies (ARABS) in a hospital cohort of patients followed for MS and to study the clinical, radiological and progressive features associated with this group.

Identification of the flotillin-1/2 heterocomplex as a target of autoantibodies in multiple sclerosis (P1.393)

Identification of the flotillin-1/2 heterocomplex as a target of autoantibodies in multiple sclerosis (P1.393)

Use of the VH6-1 gene segment to code for anti-interleukin-18 autoantibodies in multiple sclerosis.

We investigated whether levels and repertoires of anti-interleukin-18 (IL-18) autoantibodies (auto-Abs) differ in multiple sclerosis (MS) patients and healthy donors (HDs). IL-18 concentration in MS patients' sera was higher than in HD, but the level of anti-IL-18 auto-Abs was lower in MS patients. Correlation patterns of IL-18/anti-IL-18 auto-Abs system differed in HD and MS patients, so we have compared segment composition of the anti-IL-18 single-chain variable fragments (scFvs) selected from MS and naïve phage display libraries. Considerable differences between anti-IL-18 auto-Abs of these libraries were found. MS panel contained auto-Abs displaying both signs of "fetal" and somatically hypermutated repertoires. Naïve panel mainly contained the naïve antibodies. These variations from the norm are possible results of abnormal regulation of the repertoire perhaps determined by remodeling of the molecular mechanisms involved in the V(D)J recombination and/or abnormal selection by antigen in MS pathogenesis.

Quantified CSF antibody reactivity against myelin in multiple sclerosis.

Synthesis of clonal IgG is a consistent feature of patients with multiple sclerosis (MS). Whether oligoclonal bands (OCBs) represent unspecific disease bystanders or active components in MS pathology is an open question. The aim of this study was to develop a method to quantify and compare the reactivity of cerebrospinal fluid (CSF) antibodies from patients with and without MS. We collected CSF from 262 patients from two different cohorts, which included 148 patients with MS and 114 with other neurological diseases (OND). We established a highly sensitive electrochemiluminescence (ECL)-based assay to measure CSF antibody reactivity against purified myelin particles and biotin anchored liposomes. The diagnostic value of the ECL score against myelin particles was assessed with receiver operating characteristic curves. CSF from patients with MS have higher reactivity toward purified myelin particles as compared to those with OND with OCBs. Using liposomes with defined lipid compositions and myelin particles from ceramide synthase 2 (CerS2) knockout mice, we find that some of the CSF antibody reactivity is directed against cerebrosides. The ECL-based assay system expands the currently available toolbox for the detection of autoantibodies in MS and related diseases.

Changes in different parameters, lymphocyte proliferation and hematopoietic progenitor colony formation in EAE mice treated with myelin oligodendrocyte glycoprotein.

Myelin oligodendrocyte glycoprotein (MOG) is an antigen of the myelin sheath, which may trigger immune cell responses and the production of auto-antibodies in multiple sclerosis (MS). In this study, we used MOG(35-55) -induced experimental autoimmune encephalomyelitis (EAE), a model of human MS, to assess the production of catalytically active immunoglobulin G (IgG) antibodies or abzymes which have been shown to be present in sera of patients with several autoimmune diseases. Here, we show that IgGs from the sera of control C57BL/6 mice are catalytically inactive. During development of EAE, a specific reorganization of the immune system of mice occurred leading to a condition which was associated with the generation of catalytically active IgGs hydrolysing DNA, myelin basic protein (MBP) and MOG which was associated with increased proteinuria, changes in differentiation of mice bone marrow hematopoietic stem cells (HSCs) and an increase in proliferation of lymphocytes in bone marrow, spleen and thymus as well as a significant suppression of cell apoptosis in these organs. The strongest alterations were found in the early disease phase (18-24 days after immunization) and were less pronounced in later EAE stages (40 days after EAE induction). We conclude that a significant increase in DNase and proteolytic activities of antibodies may be considered the earliest statistically significant marker of MOG-induced EAE in mice. The possible differences in immune system reorganizations during preclinical phases of the disease, acute and late EAE, leading to production of different auto-antibodies and abzymes as well other changes are discussed.

B Cells and Autoantibodies in Multiple Sclerosis.

While over the past decades T cells have been considered key players in the pathogenesis of multiple sclerosis (MS), it has only recently become evident that B cells have a major contributing role. Our understanding of the role of B cells has evolved substantially following the clinical success of B cell-targeting therapies and increasing experimental evidence for significant B cell involvement. Rather than mere antibody-producing cells, it is becoming clear that they are team players with the capacity to prime and regulate T cells, and function both as pro- and anti-inflammatory mediators. However, despite tremendous efforts, the target antigen(s) of B cells in MS have yet to be identified. The first part of this review summarizes the clinical evidence and results from animal studies pointing to the relevance of B cells in the pathogenesis of MS. The second part gives an overview of the currently known potential autoantigen targets. The third part recapitulates and critically appraises the currently available B cell-directed therapies.

Differential glycosylation of KIR4.1 in glial cells affects binding of autoantibodies in multiple sclerosis

Background: Inward rectifier potassium channel 4.1 (KIR4.1) specific serum antibodies were reported in a sub-population of multiple sclerosis (MS) patients. KIR4.1 is a glycosylated channel protein expressed in oligodendrocytes and a subset of astrocytes.

To look for a needle in a haystack: the search for autoantibodies in multiple sclerosis

The search for autoantibodies in multiple sclerosis (MS) has been challenging for the last 3 decades. With the development of new proteomic methods and advances in expression and assay technologies, progress in the identification of MS autoantibodies has been made. A number of MS-specific autoantibodies have been proposed, most of them targeting proteins expressed in oligodendrocytes and along the myelin sheath. In this review, we summarize the status of antibody research in MS and then discuss recent developments and future strategies in defining and characterizing the potential antigenic targets of autoantibodies in MS.

Polyreactive Monoclonal Autoantibodies in Multiple Sclerosis: Functional Selection from Phage Display Library and Characterization by Deep Sequencing Analysis

Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system that primarily affects young and middle-aged people. It is widely accepted that B lymphocyte activation is required for MS progression. Despite the fact that the exact triggering mechanisms of MS remain enigmatic, one may suggest that MS can be induced by viral or bacterial infection in combination with specific genetic and environmental factors. Using deep sequencing and functional selection methodologies we characterized clones of poly- and cross-reactive antibodies that are capable of simultaneous recognition of viral proteins and autoantigens. The latter, in turn, possibly may trigger MS progression through molecular mimicry. It was identified that two cross-reactive antigens are probably recognized by light or heavy chains individually. According to the high structural homology between selected autoantibodies and a number of various antiviral IgGs, we suggest that a wide range of pathogens, instead of a single virus, be regarded as possible triggers of MS.

Polyreactive Monoclonal Autoantibodies in Multiple Sclerosis: Functional Selection from Phage Display Library and Characterization by Deep Sequencing Analysis

Polyreactive Monoclonal Autoantibodies in Multiple Sclerosis: Functional Selection from Phage Display Library and Characterization by Deep Sequencing Analysis

Presence of aberrant VH6 domains in anti-interferon-γ autoantibodies in multiple sclerosis

Anti-cytokine autoantibodies (auto-Abs) are ubiquitous both in patients suffering from infectious, inflammatory and autoimmune diseases and in healthy individuals. Particularly anti-IFN-γ auto-Abs are shown to be elevated in blood of multiple sclerosis (MS) patients. The aim of present study was to investigate whether repertoires of anti-IFN-γ auto-Abs differ in MS patients and healthy donors. Using phage display technique we have compared repertoires of the genes encoding anti-IFN-γ single-chain variable fragments selected from MS and naïve phage display libraries. The panel of anti-IFN-γ auto-Abs selected from MS library includes (i) 'fetal' auto-Abs, encoded by the VH6-1 gene segment and the combination proximal D segments with distal JH segments; (ii) naïve auto-Abs; (iii) affinity maturated antibodies; and (iv) abnormal single-domain antibodies. Meanwhile, the panel of anti-IFN-γ auto-Abs selected from naïve library mainly contains the naïve antibodies. Moreover, the overall antibody repertoire of MS library is skewed compared to the overall repertoire of naïve library and also contained the antibodies carrying a 'fetal' VH6 domain and the ratio of κ and λ chains was reversed. These results suggest existence of a special mechanism or trigger that provides for reconstitution of the immune system in MS.

Hunting for autoantibodies in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the CNS. Many findings support the assumption that the immune system plays a key role in the pathogenesis of MS, at least during the relapsing-remitting phase of disease.(1,2) Both arms of the adapted immune response seem to be crucial for the induction and maintenance of the autoimmune response as suggested by the success of therapies targeting T cells, B cells, or both. While genes and pathways involved in the pathogenesis of MS have emerged from recent studies, the molecular targets of the autoimmune response in MS are still largely uncertain. The identification of these targets, to better understand the pathogenesis and develop specific immune therapies, has been the focus of MS research during the last decades.

Alpha Actinin is Specifically Recognized by Multiple Sclerosis Autoantibodies Isolated Using an N-Glucosylated Peptide Epitope

Sophisticated approaches have recently led to the identification of novel autoantigens associated with Multiple Sclerosis (MuS), e.g. neurofascin, contactin, CNPase, and other T-cell receptor membrane anchored proteins. These putative antigens, although differing from the conventional myelin derivatives, are conceptually based on an animal model of experimental autoimmune encephalomyelitis. In this report we describe the identification of putative antigens based on their recognition by autoantibodies isolated from MuS patient serum. In a previous work from this laboratory we have shown that a peptide probe, named CSF114(Glc), specifically identifies serum autoantibodies in a subset of MuS patients, representing ∼30% of the patient population. The autoantibodies, purified from MuS patients' sera (six), through CSF114(Glc) affinity chromatography, detected three immunoreactive protein bands present in the rat brain. Proteomic analysis of the immunoreactive bands, involving MALDI and MS/MS techniques, revealed the presence of four proteins distinguishable by their mass: alpha fodrin, alpha actinin 1, creatine kinase, and CNPase. The immunoreactive profile of these rat brain proteins was compared with that of commercially available standard proteins by challenging against either CSF114(Glc) purified MuS autoantibodies, or monoclonal antibodies. Further discrimination among the rat brain proteins was provided by the following procedure: whereas monoclonal antibodies recognized all rat brain proteins, isolated MuS specific antibodies recognize only alpha actinin 1 as a putative antigen. In fact, alpha actinin 1 displayed a robust immunoreactive response against all MuS patients' sera examined, whereas the other three bands were not consistently detectable. Thus, alpha actinin 1, a cytoskeleton protein implicated in inflammatory/degenerative autoimmune diseases (lupus nephritis and autoimmune hepatitis) might be regarded as a novel MuS autoantigen, perhaps a prototypic biomarker for the inflammatory/degenerative process typical of the disease.

Neurofascin antibodies in inflammatory neuropathy

Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) punch above their epidemiologic weight because they need early diagnosis and treatment, can be severely disabling or fatal, and incur very high health care costs. Despite accrual of substantial information about their clinical and pathophysiologic features, the precise cause and immune targets of the commoner demyelinating form of Guillain-Barré syndrome, acute inflammatory demyelinating polyneuropathy (AIDP), and of CIDP, remain largely undiscovered. In this issue of Neurology ® , Ng et al.1 focus on autoantibody responses to a key protein in the nodal complex, neurofascin. Interest in this protein in inflammatory neuropathy extends earlier studies identifying neurofascin as a key target for pathogenic autoantibodies in multiple sclerosis.2

Conformational Landscape of N-Glycosylated Peptides Detecting Autoantibodies in Multiple Sclerosis, Revealed by Hamiltonian Replica Exchange

Synthetic N-glycosylated CSF114(Glc) and related peptides were proved to be able to recognize specific and high-affinity autoantibodies circulating in blood of relapsing-remitting multiple sclerosis (MS) patients and correlating with disease activity. The effect of these peptides has been linked to the β-turn structure around the minimal epitope Asn(Glc). In this work we performed Hamiltonian replica exchange molecular dynamics simulations on the central heptapeptide fragment of a CSF114(Glc)-derived peptide in water and in a water/hexafluoroacetone mixture, confirming a significant incidence of β-turn structures in both solvents. The structural similarity of the glycosylated and unglycosylated forms in all environments proves that the conformation of the heptapeptide is only marginally affected by the presence of the sugar. Moreover, the presence of a significant amount of bioactive hairpin-like conformations in the water environment suggests a possible use not only in the diagnosis but also in the treatment of MS.

Analysis of antibodies to surface epitopes of contactin-2 in multiple sclerosis

Contactin-2 was recently identified as an autoantigen targeted by T-cells and autoantibodies in multiple sclerosis (MS). Here we analyzed the frequency of antibodies to contactin-2 (contactin-2-ab) by a cell-based assay in the serum from 105 MS patients and at least 5years of follow-up (19 clinically isolated syndromes, 51 relapsing–remitting, 20 secondary-progressive, and 15 primary-progressive). Contactin-2-ab were detected in 4 (7.8%) relapsing–remitting patients. Clinical and magnetic resonance imaging characteristics were not significantly different from the rest of relapsing–remitting patients. In conclusion, contactin-2-ab are identified in a minority of MS patients but their presence is not associated with a particular clinical-radiological profile.

Antinuclear and antiphospholipid antibodies in patients with multiple sclerosis

The prevalence of autoantibodies in multiple sclerosis (MS) patients and their clinical associations differ between various studies. This study investigated antiphospholipid and antinuclear antibodies in 85 patients with multiple sclerosis (MS) and clinically isolated syndrome (CIS) with regard to their association with demographic features, MS specific clinical features and symptoms of connective tissue diseases. Autoantibodies tested included antinuclear antibodies (ANA) with their specificities and anticardiolipin (aCL) and anti-beta-2-glycoprotein I (anti-β2GPI) antibodies. Antinuclear antibodies were more prevalent in MS patients than in controls (63.5% vs. 3.3%; p < 0.01) and in 19% of patients specific antinuclear antibodies were detected. Anti-β2GPI IgM antibodies were more frequent in MS patients than in the control group (20% vs. 3.3%; p < 0.05). The frequency of anticardiolipin antibodies did not differ between MS patients and controls. MS patients seropositive for ANA and extractable nuclear antigens (ENA) had significantly shorter disease duration than seronegative patients (p < 0.05) and a lower disability score (Expanded Disability Status Score; EDSS) (p < 0.05). Anti-β2GPI antibodies were more frequent in patients with secondary progressive MS (SP-MS) and specific ANA antibodies were more frequent in patients with clinically isolated syndrome (CIS) (p < 0.05). The presence of autoantibodies was not associated with the predominant site of neurological involvement or the clinical features of connective tissue diseases.