Early nodal changes in the acute motor axonal neuropathy pattern of the Guillain-Barré syndrome

Guillian Barré syndrome--recent advances

Guillian Barré Syndrome (GBS) is an acquired disease of the peripheral nerves that is characterized clinically by rapidly progressing paralysis, areflexia, and albumino-cytological dissociation. It affects both genders, involves people of all ages, is reported worldwide, and in the post-polio era, it is the most common cause of an acute generalized paralysis. The clinical features are distinct and a history and an examination generally lead to a high suspicion of the diagnosis that can then be confirmed by supportive laboratory tests and electrodiagnostic studies. This review discusses the recent advances in understanding of the different variants of GBS such as acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), acute motor sensory axonal neuropathy (AMSAN), and the Fisher syndrome. The clinical, electrodiagnostic criteria, immunopathogenesis, and management of GBS and its variants are discussed.

An oligodendrocyte cell adhesion molecule at the site of assembly of the paranodal axo-glial junction

Two major isoforms of the cell adhesion molecule neurofascin NF186 and NF155 are expressed in the central nervous system (CNS). We have investigated their roles in the assembly of the node of Ranvier and show that they are targeted to distinct domains at the node. At the onset of myelination, NF186 is restricted to neurons, whereas NF155 localizes to oligodendrocytes, the myelin-forming glia of the CNS. Coincident with axon ensheathment, NF155 clusters at the paranodal regions of the myelin sheath where it localizes in apposition to the axonal adhesion molecule paranodin/contactin-associated protein (Caspr1), which is a constituent of the septate junction-like axo-glial adhesion zone. Immunoelectron microscopy confirmed that neurofascin is a glial component of the paranodal axo-glial junction. Concentration of NF155 with Caspr1 at the paranodal junctions of peripheral nerves is also a feature of Schwann cells. In Shiverer mutant mice, which assemble neither compact CNS myelin nor normal paranodes, NF155 (though largely retained at the cell body) is also distributed at ectopic sites along axons, where it colocalizes with Caspr1. Hence, NF155 is the first glial cell adhesion molecule to be identified in the paranodal axo-glial junction, where it likely interacts with axonal proteins in close association with Caspr1.

New concepts of Guillain-Barré syndrome

Guillain-Barré syndrome is an acute autoimmune polyradiculoneuropathy with a clinical presentation of flaccid paralysis with areflexia, variable sensory disturbance, and elevated cerebrospinal fluid protein without pleocytosis. Although Guillain-Barré syndrome previously had been viewed as a unitary disorder with variations, it currently is viewed as a group of syndromes with several distinctive subtypes. These include the principal subtype prevalent in the Western world (acute inflammatory demyelinating polyradiculoneuropathy, and others, each with distinctive electrodiagnostic and pathologic features, including acute motor axonal neuropathy), acute motor-sensory axonal neuropathy, Miller Fisher syndrome, and perhaps others. The clinical and pathologic features of these Guillain-Barré syndrome subtypes are reviewed, and the role of antecedent infections, particularly Campylobacter jejuni gastroenteritis, and the role of antiganglioside antibody responses are reviewed with respect to pathogenesis. Treatment of Guillain-Barré syndrome includes both important supportive measures and immunotherapies, specifically high-dose intravenous immunoglobulin and plasma exchange.

Pathogenesis of Guillain-Barré syndrome

Recent neurophysiological and pathological studies have led to a reclassification of the diseases that underlie Guillain-Barré syndrome (GBS) into acute inflammatory demyelinating polyradiculoneuropathy (AIDP), acute motor and sensory axonal neuropathy (AMSAN) and acute motor axonal neuropathy (AMAN). The Fisher syndrome of ophthalmoplegia, ataxia and areflexia is the most striking of several related conditions. Significant antecedent events include Campylobacter jejuni (4-66%), cytomegalovirus (5-15%), Epstein-Barr virus (2-10%), and Mycoplasma pneumoniae (1-5%) infections. These infections are not uniquely associated with any clinical subtype but severe axonal degeneration is more common following C. jejuni and severe sensory impairment following cytomegalovirus. Strong evidence supports an important role for antibodies to gangliosides in pathogenesis. In particular antibodies to ganglioside GM1 are present in 14-50% of patients with GBS, and are more common in cases with severe axonal degeneration associated with any subtype. Antibodies to ganglioside GQ1b are very closely associated with Fisher syndrome, its formes frustes and related syndromes. Ganglioside-like epitopes exist in the bacterial wall of C. jejuni. Infection by this and other organisms triggers an antibody response in patients with GBS but not in those with uncomplicated enteritis. The development of GBS is likely to be a consequence of special properties of the infecting organism, since some strains such as Penner 0:19 and 0:41 are particularly associated with GBS but not with enteritis. It is also likely to be a consequence of the immunogenetic background of the patient since few patients develop GBS after infection even with one of these strains. Attempts to match the subtypes of GBS to the fine specificity of anti-ganglioside antibodies and to functional effects in experimental models continue but have not yet fully explained the pathogenesis. T cells are also involved in the pathogenesis of most or perhaps all forms of GBS. T cell responses to any of three myelin proteins, P2, PO and PMP22, are sufficient to induce experimental autoimmune neuritis. Activated T cells are present in the circulation in the acute stage, up-regulate matrix metalloproteinases, cross the blood-nerve barrier and encounter their cognate antigens. Identification of the specificity of these T cell responses is still at a preliminary stage. The invasion of intact myelin sheaths by activated macrophages is difficult to explain according to a purely T cell mediated mechanism. The different patterns of GBS are probably due to the diverse interplay between antibodies and T cells of differing specificities.

Morphometric and ultrastructural changes with ageing in mouse peripheral nerve

Qualitative and quantitative information is reported on the morphological changes that occur in nerve fibres and nonneuronal cells of peripheral nerve during the lifetime of the mouse. Tibial nerves of mice aged 6-33 mo were studied. With ageing, collagen accumulates in the perineurium and lipid droplets in the perineurial cells. Macrophages and mast cells increase in number, and onion bulbs and collagen pockets are frequently present. Schwann cells associated with myelinated fibres (MF) slightly decrease in number in parallel with an increase of the internodal length from 6 to 12 mo, but increase in older nerves when demyelination and remyelination are common. The unmyelinated axon to myelinated fibre (UA/MF) ratio was about 2 until 12 mo, decreasing to 1.6 by 27 mo. In older mice, the loss of nerve fibres involves UA (50% loss of 27-33 mo cf. 6 mo) more markedly than MF (35%). In aged nerves wide incisures and infolded or outfolded myelin loops are frequent, resulting in an increased irregularity in the morphology of fibres along the internodes. In the mouse there is an adult time period, 12-20 mo, during which several features of degeneration progressively appear, and an ageing period from 20 mo upwards when the nerve suffers a general disorganisation and marked fibre loss.

Epidemiological, clinical, and electrodiagnostic findings in childhood Guillain-Barré syndrome: a reappraisal

We evaluated 61 children with Guillain-Barré syndrome, 14 months to 14 years of age, admitted to the Hospital Nacional de Pediatria in Buenos Aires. According to the electrodiagnostic findings, they fit into two groups, those with acute motor axonal neuropathy (AMAN) (18 patients) and those with acute inflammatory demyelinating polyradiculoneuropathy (AIDP) (43 patients). Ninety percent of the children with AMAN resided in suburban or rural areas without running water, whereas half of the AIDP patients lived in a metropolitan district. Summer and winter months showed a higher incidence of both variants. Children with AMAN were younger, evolved more acutely, reached a higher maximum disability score, required assisted ventilation more often, had lower mean level of cerebrospinal fluid protein, improved more slowly, and had a poorer outcome 6 months and 12 months after onset. Electrophysiological findings in those with AIDP revealed a pattern of severe diffuse slowing in children 5 years old or younger and a multifocal pattern in children 6 years old or older. This difference was not reflected in the clinical picture. In contrast, AMAN showed a uniform pattern with normal sensory conduction, severely reduced compound muscle action potential amplitude, near normal conduction velocity, and early denervation. Epidemiological, clinical, electrodiagnostic, cerebrospinal fluid, and prognostic data indicate that these variants of Guillain-Barré syndrome should be regarded as different entities.

Guillain-Barré syndrome

The concepts of Guillain-Barré syndrome have changed substantially over the last 10 years, and the last 2 years have been no exception. Guillain-Barré syndrome is now recognized as a heterogeneous disorder with many clinical manifestations. Most current investigations are centered on the hypothesis of molecular mimicry. The major challenge now is to identify the precise mechanisms of nerve fiber injury and to determine how to prevent immune injury.

The distribution of ganglioside-like moieties in peripheral nerves

GM1 ganglioside has been implicated as a target of immune attack in some diseases of the peripheral nervous system. Anti-GM1 ganglioside antibodies are associated with certain acquired immune-mediated neuropathies. It is not clear how anti-GM1 antibodies cause nerve dysfunction and injury; however, sodium and/or potassium ion channel dysfunction at the node of Ranvier has been implicated. To gain insight into the pathogenesis of these neuropathies, we examined the distribution of GM1 ganglioside and Gal(beta1-3)GalNAc moieties in nerve fibres and their relationship to voltage-gated sodium and potassium (Kv1.1, 1.5) channels at the nodes of Ranvier in peripheral nerves from human, rat and dystrophic mice. Gal(beta1-3)GalNAc moieties were localized via the binding of cholera toxin and peanut agglutinin. As a control for the specificity of these findings, we compared the distribution of GM1 moieties to that of the ganglioside GT1b. Our study provides definitive evidence for the presence of Gal(beta1-3)GalNAc bearing moieties on the axolemmal surface of mature myelinated fibres and on Schwann cells. Gal(beta1-3)GalNAc binding sites did not have an obligatory co-localization with voltage-gated sodium channels or the potassium ion channels Kv1.1 and Kv1.5 and are thus not likely carried by these ion channels. In contrast with Gal(beta1-3)GalNAc, GT1b-like moieties are restricted to the axolemma.

Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is viewed as a reactive, self-limited, autoimmune disease triggered by a preceding bacterial or viral infection. Campylobacter jejuni, a major cause of bacterial gastroenteritis worldwide, is the most frequent antecedent pathogen. It is likely that immune responses directed towards the infecting organisms are involved in the pathogenesis of GBS by cross-reaction with neural tissues. The infecting organism induces humoral and cellular immune responses that, because of the sharing of homologous epitopes (molecular mimicry), cross-react with ganglioside surface components of peripheral nerves. Immune reactions against target epitopes in Schwann-cell surface membrane or myelin result in acute inflammatory demyelinating neuropathy (85% of cases); reactions against epitopes contained in the axonal membrane cause the acute axonal forms of GBS (15% of cases). Care for such patients may be challenging, yet the prognosis overall is favourable. Optimal supportive care and anticipation and prevention of complications are the mainstay of therapy. Admission to the intensive-care unit is necessary in 33% of patients who require intubation and assisted ventilation. Immunomodulation with infusions of IgG or plasma exchange treatments foreshorten the disease course.

IgG anti-GM1 antibody is associated with reversible conduction failure and axonal degeneration in Guillain-Barré syndrome

To investigate the pathophysiological role of anti-GM1 antibody in Guillain-Barré syndrome (GBS), we reviewed sequential nerve conduction studies of 345 nerves in 34 GBS patients. Statistically significant correlation between IgG anti-GM1 antibodies and electrodiagnoses was found. Sixteen IgG anti-GM1-positive patients were classified as having acute motor or acute motor sensory axonal neuropathy (AMAN or AMSAN) (12 patients), as having acute inflammatory demyelinating polyneuropathy (AIDP) (3 patients), or as undetermined (1 patient) by electrodiagnostic criteria. Besides axonal features, there was rapid resolution of conduction slowing and block. In 3 patients initially diagnosed as having AIDP, conduction slowing was resolved within days, and 1 of them and 3 AMAN patients showed markedly rapid increases in amplitudes of distal compound muscle action potentials that were not accompanied by prolonged duration and polyphasia. The time courses of conduction abnormalities were distinct from those in IgG anti-GM1-negative AIDP patients. Rapid resolution of conduction slowing and block, and the absence of remyelinating slow components, suggest that conduction failure may be caused by impaired physiological conduction at the nodes of Ranvier. Reversible conduction failure as well as axonal degeneration constitutes the pathophysiological mechanisms in IgG anti-GM1-positive GBS. In both cases, immune-mediated attack probably occurs on the axolemma of motor fibers.

Small-fiber sensory neuropathies: clinical course and neuropathology of idiopathic cases

We describe the clinical features, natural history, and neuropathology of 32 patients presenting with "burning feet," for whom no specific cause was identified. All had neuropathic pain in the feet and morphological abnormalities of cutaneous innervation in skin obtained using punch biopsy. Most (29) had an abnormal sensory examination. All had normal strength, proprioception, tendon reflexes, and nerve conductions. Two clinical patterns were apparent, based on natural history and spatial distribution of cutaneous denervation. Most (28) patients presented with neuropathic pain initially restricted to the feet and toes but extending more proximally to involve the legs and hands with time. Intraepidermal nerve fiber (IENF) density was most severely reduced distally, with more normal IENF densities in skin from proximal sites. In contrast, a minority (4) presented with the abrupt onset of generalized cutaneous burning pain and hyperesthesia. In these patients, IENF densities were reduced in skin from both proximal and distal sites. Absolute IENF densities in calf skin were reduced below the lower limit of normal (5th percentile) in 26 (81%). Of the 6 who underwent sural nerve biopsy, 4 had selective loss of small myelinated and/or unmyelinated axons and 2 had normal histology and fiber densities despite reduced IENF densities in skin biopsy specimens. Punch skin biopsy from proximal and distal sites is a useful means of assessing these distinctive patients and may provide further insight into pathophysiology.

Campylobacter species and Guillain-Barré syndrome

Since the eradication of polio in most parts of the world, Guillain-Barré syndrome (GBS) has become the most common cause of acute flaccid paralysis. GBS is an autoimmune disorder of the peripheral nervous system characterized by weakness, usually symmetrical, evolving over a period of several days or more. Since laboratories began to isolate Campylobacter species from stool specimens some 20 years ago, there have been many reports of GBS following Campylobacter infection. Only during the past few years has strong evidence supporting this association developed. Campylobacter infection is now known as the single most identifiable antecedent infection associated with the development of GBS. Campylobacter is thought to cause this autoimmune disease through a mechanism called molecular mimicry, whereby Campylobacter contains ganglioside-like epitopes in the lipopolysaccharide moiety that elicit autoantibodies reacting with peripheral nerve targets. Campylobacter is associated with several pathologic forms of GBS, including the demyelinating (acute inflammatory demyelinating polyneuropathy) and axonal (acute motor axonal neuropathy) forms. Different strains of Campylobacter as well as host factors likely play an important role in determining who develops GBS as well as the nerve targets for the host immune attack of peripheral nerves. The purpose of this review is to summarize our current knowledge about the clinical, epidemiological, pathogenetic, and laboratory aspects of campylobacter-associated GBS.

Molecular mimicry in Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is the commonest cause of acute flaccid paralysis worldwide. Recent pathological and electrodiagnostic studies indicated that there are different patterns within this syndrome. The demyelinating pattern predominates in North America and Europe, whereas axonal variants of GBS occur more frequently in Northern China. Infection with Campylobacter jejuni is one of the most frequently recognized antecedent events in all variants of GBS. The lipopolysaccharides of these organisms share ganglioside-like epitopes with peripheral nerves, and patients with GBS have antiganglioside antibodies. These observations have given rise to the hypothesis that "molecular mimicry" is the immunopathogenic mechanism of injury to peripheral nerve fibers. With this hypothesis in view, we summarize our experience of GBS as it occurs in Northern China. To explore the role of molecular mimicry in this cohort we sought evidence of preceding Campylobacter infection and correlated this with clinical characteristics and antiganglioside serology. Based on our results we propose a sequence of pathogenic events leading to peripheral nerve injury in GBS.

The role of antiglycolipid antibodies in neurological disorders

Glycolipids have been shown to be antigens for circulating antibodies in autoimmune processes affecting the nervous system like neuropathy associated with IgM paraproteinemia, Guillain Barré syndrome (GBS), multifocal neuropathy, and variants thereof. The antibody titers, the Ig-classes, and the antibody specificity vary between studies and disease groups. The immunogens are in general unknown. However, GBS is often associated with an infection with Campylobacter jejuni, which expresses a lipopolysaccharide structure similar to the carbohydrate epitopes in sialic acid containing glycolipids and gangliosides and thus a potential primary antigen for antiganglioside antibodies. The antiglycolipid specificity will most likely reflect the primary antigen carbohydrate epitopes, which also determine the target cell or tissue structure and the pathology. These factors might add to the inconsistent results obtained and that have led to the question: Are antiglycolipid antibodies of any clinical significance?

Guillain-Barré syndrome and Fisher's syndrome following Campylobacter jejuni infection

The patients with Guillain-Barré Syndrome (GBS) subsequent to Campylobacter jejuni enteritis showed axonal degeneration and had IgG anti-GM1 antibody. The most frequently isolated C. jejuni from the patients was specific serotype of Penner's 19 in Japan. In the lipopolysaccharide (LPS) in C. jejuni of this serotype, the same oligosaccharide structure as GM1 ganglioside existed, suggesting the molecular mimicry between GM1 in nervous tissue and C. jejuni LPS. IgG anti-GM1 antibody may bind the nodes of Ranvier and axon terminals and causes degeneration of the motor axon. Some patients develop Fisher's syndrome following C. jejuni infection. C. jejuni strains from the patients who had IgG anti-GQ1b antibody in the acute phase had GQ1b epitope in their LPS, and the molecular mimicry between GQ1b in nervous tissue and an antecedent infectious agent was clarified.

Human autoimmune neuropathies

Peripheral nerve diseases are among the most prevalent disorders of the nervous system. Because of the accessibility of the peripheral nervous system (PNS) to direct physiological and pathological study, neuropathies have traditionally played a unique role in developing our understanding of basic mechanism of nervous system injury and repair. At present they are providing new insight into the mechanisms of immune injury to the nervous system. A rapidly growing catalogue of PNS disorders are now suspected to be immune-mediated, and in the best understood of these disorders, the molecular and cellular targets of immune attack are known, and the pathophysiology follows directly from the specific immune injury. This review summarizes the immunologically relevant features of the PNS, then considers selected immune-mediated neuropathies, focusing on pathogenetic mechanisms. Finally, the PNS is providing a testing ground for new immunotherapies and approaches to protection and regeneration, including the use of trophic factors. The current status of treatment and implications for future approaches is reviewed.

Paranodin, a glycoprotein of neuronal paranodal membranes

Ranvier nodes are flanked by paranodal regions, at the level of which oligodendrocytes or Schwann cells interact closely with axons. Paranodes play a critical role in the physiological properties of myelinated nerve fibers. Paranodin, a prominent 180 kDa transmembrane neuronal glycoprotein, was purified and cloned from adult rat brain, and found to be highly concentrated in axonal membranes at their junction with myelinating glial cells, in paranodes of central and peripheral nerve fibers. The large extracellular domain of paranodin is related to neurexins, and its short intracellular tail binds protein 4.1, a cytoskeleton-anchoring protein. Paranodin may be a critical component of the macromolecular complex involved in the tight interactions between axons and myelinating glial cells characteristic of the paranodal region.

Fulminant Guillain-Barré syndrome with universal inexcitability of peripheral nerves: a clinicopathological study

The pathological basis of nerve inexcitability in Guillain-Barré syndrome has not been established with certainty. We report the clinicopathological findings in a 67-year-old patient with fulminant Guillain-Barré syndrome who died 18 days after onset. Three serial electrophysiological studies revealed nerve inexcitability. Antibodies to Campylobacter jejuni were present but there was no antiganglioside reactivity. Spinal root sections revealed extensive and almost pure macrophage-associated demyelination with occasional presence of T lymphocytes and neutrophil leukocytes. Conversely, in femoral, median, and sural nerves the outstanding lesion was axonal degeneration, with some denuded axons remaining. Unmyelinated fibers, posterior root ganglia, and dorsal columns were preserved. Endoneurial postcapillary venules showed plump endothelial cells with loss of their tight junctions. We conclude that both primary demyelination and axonal degeneration secondary to inflammation account for nerve inexcitability. Our findings lend support to the hypothesis of increased endoneurial pressure as the cause of wallerian degeneration in nerve trunks.

Molecular composition of the node of Ranvier: identification of ankyrin-binding cell adhesion molecules neurofascin (mucin+/third FNIII domain-) and NrCAM at nodal axon segments

Neurofascin, NrCAM, L1, and NgCAM are a family of Ig/FNIII cell adhesion molecules that share ankyrin-binding activity in their cytoplasmic domains, and are candidates to form membrane-spanning complexes with members of the ankyrin family of spectrin-binding proteins in a variety of cellular contexts in the nervous system. Specialized forms of ankyrin, 270 kD and/or 480 kD ankyrinG are components of the membrane undercoat of axons at the node of Ranvier. This paper focuses on definition of the isoforms of ankyrin-binding cell adhesion molecules localized with ankyrinG at the nodal axon segment. The exon usage of two major forms of neurofascin was determined by isolation of full-length cDNAs and used to prepare isoform-specific antibodies. An isoform of neurofascin containing a mucin-like domain and lacking the third FNIII domain was concentrated at axon initial segments and colocalized at nodes of Ranvier with ankyrinG and the voltage-dependent sodium channel. An alternative form of neurofascin lacking the mucin-like domain and containing the third FNIII domain was present in unmyelinated axons. The antibody initially raised against neurofascin was used to screen a rat brain cDNA expression library. In addition to neurofascin, this screen yielded a clone with 80% sequence identity to NrCAM from chicken. The sequences of two full-length cDNAs are presented. NrCAM is most closely related to neurofascin among the other members of the L1/neurofascin/NgCAM family, with over 70% identity between cytoplasmic domains. NrCAM, visualized with antibodies specific for the ecto-domain, also was found to be coexpressed with neurofascin at nodes of Ranvier and at axon initial segments. This is the first characterization of defined neuronal cell adhesion molecules localized to axonal membranes at the node of Ranvier of myelinated axons.

Acute motor axonal neuropathy: an antibody-mediated attack on axolemma

The acute motor axonal neuropathy (AMAN) form of the Guillain-Barre syndrome is a paralytic disorder of abrupt onset characterized pathologically by motor nerve fiber degeneration of variable severity and by sparing of sensory fibers. There is little demyelination or lymphocytic inflammation. Most cases have antecedent infection with Campylobacter jejuni and many have antibodies directed toward GM1 ganglioside-like epitopes, but the mechanism of nerve-fiber injury has not been defined. In 7 fatal cases of AMAN, immunocytochemistry demonstrated the presence of IgG and the complement activation product C3d bound to the axolemma of motor fibers. The most frequently involved site was the nodal axolemma, but in more severe cases IgG and C3d were found within the periaxonal space of the myelinated internodes, bound to the outer surface of the motor axon. These results suggest that AMAN is a novel disorder caused by an antibody- and complement-mediated attack on the axolemma of motor fibers.

Experimental Campylobacter jejuni infection in the chicken: an animal model of axonal Guillain-Barré syndrome

OBJECTIVE

To develop and characterise an animal model of paralytic neuropathy after Campylobacter jejuni infection. Campylobacter infection precedes development of many cases of Guillain-Barré syndrome and is particularly associated with cases having prominent axonal degeneration. Understanding the pathogenesis of Guillain-Barré syndrome after C jejuni infection has been slowed by the lack of animal models.

METHODS

A spontaneous paralytic neuropathy is described that developed in chickens from the farms of four patients with Guillain-Barré syndrome. The production of paralytic neuropathy in chickens experimentally fed Campylobacter jejuni isolated from one of these patients is reported. The sciatic nerves of the spontaneously paralysed chickens were examined pathologically in teased fibres, in plastic embedded sections, and by electron microscopy. Two large groups of chickens were then fed cultures of a C jejuni (Penner type O:19) isolated from one of these patients.

RESULTS

The chickens with spontaneous paralysis had pathologically noninflammatory neuropathy. Pathology in the sciatic nerves ranged from no detectable changes to severe Wallerian-like degeneration. In the experimentally inoculated groups, an average of 33% of the chickens became paralysed. The median time after inoculation to paralysis was 12 days. The lesions found in the first few days of paralysis included nodal lengthening and paranodal demyelination. In those animals that survived for several days after onset of weakness, the pathology was dominated by extensive Wallerian-like degeneration. Animals that survived for weeks with no clinically apparent neuropathy had paranodal remyelination in some teased nerve fibres, reflecting earlier paranodal demyelination.

CONCLUSION

Experimental inoculation with C jejuni may provide a new model for understanding some forms of Guillain-Barré syndrome.

Antibodies to GM1 and Gal(beta 1-3)GalNAc at the nodes of Ranvier in human and experimental autoimmune neuropathy

Autoantibodies to Gal(beta 1-3)GalNAc epitopes on glycolipids and glycoproteins are associated with motor neuron disease and motor or sensorimotor neuropathy. These epitopes are ubiquitously distributed on cell surfaces. In the nervous system they are present on axons and myelin, specifically also at the nodes of Ranvier. Binding of GM1 antibodies to the nodal area may contribute to disease development in some of these conditions.