Association of antibodies to ganglioside complexes and conduction blocks in axonal Guillain‐Barré syndrome presenting as acute motor conduction block neuropathy

A close relationship between acute motor conduction block neuropathy and antibodies against the complex of GM1 and GalNAc‐GD1a has been reported. This study investigates the hypothesis that conduction block at the early phase of axonal Guillain‐Barré syndrome (GBS) is also associated with such ganglioside complexes. Sera were obtained from seven French patients with initial evidence of isolated conduction blocks that resolved or progressed to acute motor axonal neuropathy. Serum IgG to asialo‐GM1 and gangliosides of LM1, GM1, GM1b, GD1a, GalNAc‐GD1a, GD1b, GT1a, GT1b, and GQ1b as well as their complexes were measured. Five of seven patients progressed within the first month of disease to AMAN. One patient had IgG antibodies against the complex of asialo‐GM1 and each of the other ganglioside antigens. Another patient carried IgG antibodies against GM1 complex with GM1b, GD1a, and GT1a as well as asialo‐GM1 complex with GD1a and GT1a. None had IgG antibodies against GM1/GalNAc‐GD1a complex. Six patients had IgG against single antigens GM1, GD1a, GalNAc‐GD1a, GD1b, and asialo‐GM1. In three patients, a reduced reaction against GM1/GalNAc‐GD1a complex was observed. The presence of conduction block in axonal GBS is not always associated with anti‐GM1/GalNAc‐GD1a complex antibodies.     

Dysfunction of nodes of Ranvier: a mechanism for anti-ganglioside antibody-mediated neuropathies

Autoantibodies against gangliosides GM1 or GD1a are associated with acute motor axonal neuropathy (AMAN) and acute motor-sensory axonal neuropathy (AMSAN), whereas antibodies to GD1b ganglioside are detected in acute sensory ataxic neuropathy (ASAN). These neuropathies have been proposed to be closely related and comprise a continuous spectrum, although the underlying mechanisms, especially for sensory nerve involvement, are still unclear. Antibodies to GM1 and GD1a have been proposed to disrupt the nodes of Ranvier in motor nerves via complement pathway. We hypothesized that the disruption of nodes of Ranvier is a common mechanism whereby various anti-ganglioside antibodies found in these neuropathies lead to nervous system dysfunction. Here, we show that the IgG monoclonal anti-GD1a/GT1b antibody injected into rat sciatic nerves caused deposition of IgG and complement products on the nodal axolemma and disrupted clusters of nodal and paranodal molecules predominantly in motor nerves, and induced early reversible motor nerve conduction block. Injection of IgG monoclonal anti-GD1b antibody induced nodal disruption predominantly in sensory nerves. In an ASAN rabbit model associated with IgG anti-GD1b antibodies, complement-mediated nodal disruption was observed predominantly in sensory nerves. In an AMAN rabbit model associated with IgG anti-GM1 antibodies, complement attack of nodes was found primarily in motor nerves, but occasionally in sensory nerves as well. Periaxonal macrophages and axonal degeneration were observed in dorsal roots from ASAN rabbits and AMAN rabbits. Thus, nodal disruption may be a common mechanism in immune-mediated neuropathies associated with autoantibodies to gangliosides GM1, GD1a, or GD1b, providing an explanation for the continuous spectrum of AMAN, AMSAN, and ASAN.     

Fine specificities of anti-LM1 IgG antibodies in Guillain-Barré syndrome

We investigated the prevalence of anti-LM1 IgG antibody and its fine specificity in Guillain-Barré syndrome (GBS). Anti-LM1 IgG and IgM antibodies from sera of 47 patients with GBS--19 with acute inflammatory demyelinating polyneuropathy (AIDP), 27 with acute motor axonal neuropathy (AMAN), and 1 with acute motor-sensory axonal neuropathy (AMSAN)--were tested. Anti-LM1 IgG antibody was detected in only one patient with AIDP, whereas it was present in seven with AMAN and in one with AMSAN. Sera from the eight IgG anti-LM1-positive patients with AMAN/AMSAN also had IgG activity against the gangliosides GM1, GM1b, GD1a, GalNAc-GD1a, GD1b, or GQ1b. Anti-LM1 IgG antibodies from the AMAN/AMSAN patients cross-reacted with other gangliosides, whereas IgG antibody from the AIDP patient was monospecific against LM1. Anti-LM1 IgG antibody therefore, cannot be a marker of AIDP. In addition, whether monospecific anti-LM1 IgG antibody is associated with AIDP remains to be concluded. Larger studies are needed to verify whether monospecific anti-LM1 IgG antibody could be a marker of AIDP.     

Axonal Guillain-Barré syndrome: carbohydrate mimicry and pathophysiology

Abstract   Acute motor axonal neuropathy (AMAN), an axonal subtype of Guillain-Barré syndrome (GBS), is characterized by pure motor involvement, frequent antecedent infection by Campylobacter jejuni , association with anti-GM1 or anti-GD1a immunoglobulin G (IgG) antibodies, and the electrophysiological features of axonal degeneration and reversible conduction block. Molecular mimicry exists between GM1 and GD1a gangliosides and lipooligosaccharides (LOSs) of C. jejuni isolates from AMAN. Sensitization of rabbits with GM1 or C. jejuni LOS induces anti-GM1 IgG antibodies and subsequent flaccid paralysis. Pathological changes seen in rabbit model peripheral nerves are identical to those in human AMAN. Immunohistochemistry of AMAN rabbits shows disruption of nodal sodium channel clusters and detachment of paranodal myelin terminal loops, similar to paranodal demyelination, which would significantly reduce the safety factor for impulse transmission and might be responsible for the rapidly reversible conduction block frequently present in human AMAN. C. jejuni sialyltransferase (Cst-II), which functions in the biosynthesis of ganglioside-like LOSs, determines the transferase activity. Strains with cst-II (Thr51) express GM1 and GD1a epitopes, whereas GBS patients infected with cst-II (Thr51) strains have anti-GM1 or anti-GD1a IgG antibodies. The cst-II gene is responsible for the development of GBS. Immunological, pathological, electrophysiological, and bacteriological studies have provided strong evidence of carbohydrate mimicry being a cause of AMAN and clarified the mechanisms of nerve conduction failure in AMAN.     

Detection of anti-ganglioside antibodies in Guillain-Barré syndrome and its variants by the agglutination assay

Sera from 40 patients with Guillain-Barré syndrome (GBS), including the subtypes acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), acute motor and sensory axonal neuropathy (AMSAN), and Miller Fisher syndrome (MFS) were examined for the presence of anti-ganglioside antibodies using the ganglioside agglutination assay, and the enzyme-linked immunosorbent assay (ELISA). In the ELISA system, sera were tested for IgM and IgG antibodies to GM1, GM2, GD1a, GD1b, GT1b, and GQ1b gangliosides. Antibodies to gangliosides were detected in 21 (53%) of the GBS patients by agglutination assay and in 17 (43%) of the patients by ELISA. Some of the sera reacted with more than one ganglioside. Antibodies were not found in the control sera that were studied. The agglutination assay may be useful for rapid screening of GBS sera for antibodies to multiple gangliosides.     

Early discrimination of sensorimotor Guillain‐Barré syndrome into demyelinating or axonal subtype by automated nerve excitability testing

In the early stage of disease, differentiating acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor sensory axonal neuropathy (AMSAN) using only a conventional nerve conduction studies (NCS) may be difficult. We evaluated the differences in the motor axonal excitability properties of 16 cases of sensorimotor Guillain‐Barré syndrome by nerve excitability testing (NET). The antiganglioside antibody assay and follow‐up NCS resulted in 12 patients diagnosed as AIDP and 4 patients as AMSAN. Clinical and excitability parameters in each group were compared with those in 30 normal controls. Automated NET with threshold tracking techniques was used to calculate the strength–duration time constant (SDTC), threshold electrotonus (TE), current–threshold relationship (CTR), and recovery cycle (RC) of excitability. Except for subtle changes in excitability parameters, AIDP showed no definitive difference relative to normal controls. Comparison between AMSAN and normal controls also revealed no significant differences in the SDTC, TE, and CTR parameters. However, there were clear differences in some of the RC parameters: the relative refractory period was significantly longer in the AMSAN group than in the AIDP group (4.40 ± 1.11 vs. 3.09 ± 1.01 ms, mean ± SEM; p < 0.001), while superexcitability was significantly less prominent in the AMSAN group (?6.80 ± 10.30 vs. ?26.48 ± 1.17%, mean ± SEM; p < 0.001). Our study identified that both AIDP and AMSAN were associated with subtle changes in excitability properties. Nonetheless, the prominent increase in refractoriness in AMSAN suggests the presence of a nodal conduction block.     

Axonal conduction block at intermediate nerve segments in pure motor Guillain-Barré syndrome

The pathophysiology of axonal Guillain-Barré syndrome (GBS) is not simple axonal degeneration, but includes reversible conduction failure. Acute motor axonal neuropathy (AMAN) and acute motor conduction block (CB) neuropathy are the two subtypes of pure motor axonal GBS, but their nosologic boundary is still in debate. We investigated clinical and electrophysiological features of 21 consecutive patients with GBS in Korea. Analysis was focused on the presence of CB at intermediate nerve segments (iCB) in pure motor GBS, and its serial changes during the acute phase of disease. Pure motor GBS was common (81%), and iCB was observed in 12 patients with pure motor GBS. Clinical features of pure motor GBS with iCB were distinct from sensorimotor GBS, but similar to pure motor GBS without iCB, characterized by frequent preceding diarrhea, uncommon cranial nerve palsy, and fast recovery. The iCB was not restricted to common entrapment sites, and the distal segments were also commonly involved in the nerves with iCB. The temporal course of iCB was marked by a rapid and often disproportionate increase of proximal and distal amplitudes without remyelinating slow components. Clinical and electrophysiological features of pure motor GBS in patients with iCB suggest that acute motor CB neuropathy may constitute a spectrum of axonal GBS, sharing a common pathomechanism with AMAN.     

Guillain‐Barré syndrome: subtypes and predictors of outcome from India

There is a paucity of large studies evaluating the subtypes of Guillain‐Barré syndrome (GBS) and their outcome from Southeast Asia. We report cliniconeurophysiological subtypes of GBS and their correlation with triggering events and 3‐month outcome from northern India. Three hundred and twenty eight consecutive patients with GBS were clinically evaluated, including their triggers, severity, autonomic involvement, cranial nerve palsy, and respiratory paralysis. Nerve conduction study (NCS) was repeated at 3 weeks if the initial study was normal. They were categorized into acute inflammatory demyelinating polyradiculoneuropathy (AIDP), acute motor axonal neuropathy (AMAN), acute motor sensory axonal neuropathy (AMSAN), inexcitable motor nerve, and equivocal. Clinically, 204 (62.2%) patients had pure motor, 106 (32.3%) motor sensory, 16 (4.9%) Miller Fisher syndrome, and 2 (0.6%) pure sensory GBS. Based on NCS, 242 (73.8%) had AIDP, 44 (13.4%) AMAN, 15 (4.6%) AMSAN, 8 (2.4%) inexcitable motor nerves, and 27 (8.2%) equivocal GBS. AIDP patients were older, more common in summer, had lesser peak disability, and better outcome compared to those with AMAN. Eleven (3.4%) patients died and 48 (14.6%) had poor outcome at 3 months. The poor outcome was related to severity, dysautonomia, and inexcitable motor nerves. AIDP is the commonest variant of GBS in our study and has better outcome compared to AMAN.     

Axonal Guillain-Barré syndrome: relation to anti-ganglioside antibodies and Campylobacter jejuni infection in Japan

To clarify the relations of the axonal form of Guillain-Barré syndrome (GBS) to anti-ganglioside antibodies and Campylobacter jejuni infection, 86 consecutive Japanese GBS patients were studied. Electrodiagnostic criteria showed acute inflammatory demyelinating polyneuropathy in 36% of the patients and acute motor axonal neuropathy (AMAN) in 38%. Frequent anti-ganglioside antibodies were of the IgG class and against GM1 (40%), GD1a (30%), GalNAc-GD1a (17%), and GD1b (21%). Identified infections were C. jejuni (23%), cytomegalovirus (10%), Mycoplasma pneumoniae (6%), and Epstein-Barr virus (3%). There was a strong association between AMAN and IgG antibodies against GM1, GD1a, GalNAc-GD1a, or GD1b. Almost all the patients with at least one of these antibodies had the AMAN pattern or rapid resolution of conduction slowing/block possibly because of early-reversible changes on the axolemma. C. jejuni infection was frequently associated with AMAN or anti-ganglioside antibodies, but more than half of the patients with AMAN or anti-ganglioside antibodies were C. jejuni-negative. These findings suggest that the three phenomena "axonal dysfunctions (AMAN or early-reversible conduction failure)," "IgG antibodies against GM1, GD1a, GalNAc-GD1a, or GD1b," and "C. jejuni infection" are closely associated but that microorganisms other than C. jejuni frequently trigger an anti-ganglioside response and elicit axonal GBS.     

Case of acute motor conduction block neuropathy (AMCBN)

We describe a 21 year‐old man with an acute development of weakness whose clinical and serial electrophysiological findings were atypical for Guillain–Barré syndrome. Electrophysiological data suggested a diagnosis of “acute motor conduction block neuropathy” (AMCBN). The 6 months of disease duration and the electrophysiological follow‐up, which never showed axonal degeneration until complete clinical recovery, raise the issue of the relationship between AMCBN and acute motor axonal neuropathy (AMAN). Muscle Nerve 39: 224–226, 2009     

Electrophysiological subtypes and associated prognosis factors of Mexican adults diagnosed with Guillain-Barré syndrome,a single center experience

BackgroundThe clinical characteristics of electrophysiological subtypes and prognostic factors of Mexican adults diagnosed with Guillain-Barré Syndrome (GBS) have not been described.Materials and methodsA single center, ambispective, cohort study was performed (2015–2019). GBS was defined following the Asbury and Cornblath criteria. Electrodiagnosis was made according to Hadden criteria. Clinical, biochemical and electrodiagnostic parameters were described, compared and analyzed using a multivariate model. Only patients who completed a 3-month follow-up were included.Results137 GBS patients (92 males; mean age 46.6 ± 16.6). 132 (96.3%) underwent an electrodiagnostic assessment. 68 (51.5%) were classified as axonal GBS, with further classified into two groups: acute motor axonal neuropathy (AMAN) 45.4%, and acute motor and sensory axonal neuropathy (AMSAN) 8,6%. The following characteristics were lower in the AMAN group: Medical Research Counsel sumscore (MRC) 30.1 ± 16.3 vs 36.4 ± 14.4, unilateral facial palsy 10% vs 25.9% and albuminocytologic dissociation 41.3% vs. 71.7%. Multivariate analysis found AMAN as an independent predictor of an unfavorable outcome OR: 3.34 (p = 0.03)ConclusionsAMAN subtype is the most frequent presentation of GBS in Mexican adult patients and an independent predictor of inability to walk independently at 3 months after discharge.     

Time course of axonal regeneration in acute motor axonal neuropathy

Patients with acute motor axonal neuropathy (AMAN) generally recover well. We reviewed clinical and electrophysiologic recovery in 13 patients for up to 5 years. Twelve patients showed rapid recovery over 12 months, whereas in the remaining one the recovery was slow and incomplete at 5 years. In AMAN, axonal degeneration appears to develop predominantly in the motor nerve terminals, and only occasionally more proximally in the nerve roots. Nerve terminal degeneration-regeneration presumably provides a mechanism for good recovery.     

Evolving pattern of Guillain-Barre syndrome in a community hospital in Israel

Objectives –  To investigate the frequency of axonal Guillain–Barre syndrome (GBS) in our ward over 6 years (1999–2005).
Materials and methods –  Clinical and electrophysiological findings of 40 patients admitted to neurology with abnormalities compatible with acute motor axonal neuropathy (AMAN), acute motor sensory axonal neuropathy (AMSAN) and acute inflammatory demyelinating polyneuropathy (AIDP) were reviewed.
Results –  Electrophysiological findings showed that 25 (63%) patients had AIDP, nine (22%) AMAN and six (15%) AMSAN. There were significant differences in disease severity. Most axonal patients (87%) were hospitalized with moderate or severe symptoms (3–4 Hughes grade score) and progressed to severe grade (4–6) in comparison with AIDP patients (64% admitted with mild forms) (1–2 Hughes grade score) and progressed to severe in 44% of cases. Cranial nerve involvement was more frequent in AIDP (56%) in comparison with the axonal type (13%). Raised cerebrospinal fluid protein at the time of hospitalization was observed in 76% of demyelinating and 33% of axonal patients.
Conclusions –  Axonal GBS occurred more frequently in Israel compared with other Western countries.     

Increased incidence of axonal Guillain‐Barré syndrome in La Spezia area of Italy: A 13‐year follow‐up study

Guillain‐Barré syndrome (GBS) is an acute immune‐mediated polyradiculoneuropathy with a worldwide incidence of 0.81‐1.89 per 100 000 person‐years. In Europe and North America only 5% of patients with GBS have axonal subtypes, which in South America and Asia account for 30%‐47% of cases. The aim of our study is to assess the annual incidence and clinical features of GBS in La Spezia area in Italy. A retrospective (from 1 January 2003 to 31 December 2011) followed by a prospective (from 1 January 2012 to 31 December 2015) analysis was carried out on patients admitted to La Spezia hospital who fulfilled the GBS diagnostic criteria. A total of 86 patients (58 men), mean age of 62.7 years (range 21‐90), were included. The mean annual incidence rate was 3/100 000 (range: 0.9/100 000‐5.37/100 000) significantly higher than the European incidence (P < 0.001). Forty‐seven percent were classified as acute inflammatory demyelinating polyradiculoneuropathy (AIDP), 35% as acute motor and motor‐sensory axonal neuropathy (AMAN‐AMSAN), 13% as variant forms, and 5% were not defined. AIDP was most common in “Golfo dei Poeti” (50%) and “Val di Magra” (63.2%), whereas AMAN/AMSAN prevailed in “Val di Vara” (63.6%) and “Riviera Spezzina” (62.5%) (P = 0.024). In La Spezia area GBS incidence (especially the AMAN subtype) is significantly higher than the incidence reported in Europe. AIDP predominates in the eastern area whereas AMAN/AMSAN in the western, with a significantly different incidence rate (P = 0.003). Prospective studies to assess possible predisposing environmental factors are needed.     

Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is currently divided into the two major subtypes: acute inflammatory demyelinating polyneuropathy (AIDP) and acute motor axonal neuropathy (AMAN). This review highlights relevant recent publications, particularly on the pathophysiology of AMAN. Molecular mimicry of the bacterial lipo-oligosaccharide by the human gangliosides is now considered an important cause of AMAN. Gangliosides GM1, GM1b, GD1a, and GalNAc-GD1a expressed on the motor axolemma are likely to be the epitopes for antibodies in AMAN. At the nodes or paranodes, deposition of antiganglioside antibodies initially cause reversible conduction block followed by axonal degeneration. Electrodiagnostic findings support this process. Disruption of glycolipids, which are important to maintain ion channel clustering at the nodes and paranode, may impair nerve conduction. Genetic polymorphisms of Campylobacter jejuni determine the expression of the gangliosides on the bacterial wall. In contrast, target molecules in AIDP have not yet been identified. Meta-analyses show efficacy of plasmapheresis and immunoglobulin therapy, but not corticosteroids, in hastening recovery.     

Inflammatory infiltrates in the spinal cord of patients with Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is defined as an acute inflammatory demyelinating polyradiculoneuropathy (AIDP) of the peripheral nervous system. Reports on central nervous system involvement in patients with GBS are rare and the histopathological analysis was usually restricted to conventional staining techniques. We were able to investigate four cases with GBS at autopsy in respect to the inflammatory infiltrates and histopathological changes in the spinal cord by immunohistochemistry using a panel of antibodies recognizing lymphocytes and different macrophage-activation antigens. There were increased inflammatory cell infiltrates comprising lymphocytes and macrophages in the spinal cord of two cases. In one of these two cases, GBS predominantly affecting the motor system similar to acute motor axonal neuropathy (AMAN) developed following hepatitis B vaccination; in the second one, GBS developed rapidly 4 days after onset of intravenous purified GM1-ganglioside application affecting the motor as well as the sensory system, resembling acute motor sensory axonal neuropathy (AMSAN). Impairment of the spinal anterior horn cells with their axons was suggested to be responsible for prolonged motor symptoms and the predominantly axonal type of neuropathy at least as a late-stage feature in these two cases with fatal outcome. Insignificant cellular infiltrates in the spinal cord were noted in the other two GBS cases. Focal cellular infiltration of spinal nerve roots and meninges was similar in all cases.     

Anti‐ganglioside antibodies in Guillain–Barré syndrome and chronic inflammatory demyelinating polyneuropathy in Chinese patients

Introduction: In this study we investigated the relationships between anti‐ganglioside antibodies and Guillain–Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP). Methods: Samples from 48 Chinese patients diagnosed with GBS and 18 patients diagnosed with CIDP were retrospectively reviewed. Results: In the GBS patients, 62.5% were classified as having acute inflammatory demyelinating polyneuropathy (AIDP), 27.1% were found to have acute motor axonal neuropathy (AMAN), and 10.4% were unclassified. Serum IgG anti‐ganglioside antibodies were detected in 46.2% of the AMAN patients and in 6.7% of the AIDP patients (P < 0.05); 5.6% of the 18 CIDP patients were IgG antibody positive, and 27.8% were IgM antibody positive. Facial palsy and sensory impairment were significantly associated with IgM antibodies. Conclusions: These results suggest that IgG anti‐GM1 antibodies are associated with AMAN, but not with AIDP, and that IgM antibodies against GM1, GM2, and GM3 are associated with facial nerve palsy. Muscle Nerve 55 : 470–475, 2017     

Guillain-Barré syndrome: An update

Guillain-Barré syndrome (GBS) is an acute polyneuropathy consisting of different subtypes. Acute inflammatory demyelinating polyradiculoneuropathy, the classic demyelinating form of GBS, accounts for 90% of all GBS cases in the Western world. Acute motor axonal neuropathy (AMAN) and acute motor and sensory axonal neuropathy (AMSAN) are axonal forms of GBS that are more prevalent in Asia, South and Central America, often preceded by infection by Campylobacter jejuni. AMAN and AMSAN may be mediated by specific anti-ganglioside antibodies that inhibit transient sodium ion (Na⁺) channels. The efficacy of plasmapheresis and intravenous immunoglobulin has been established in large international randomised trials, with corticosteroids proven ineffective. Although axonal demyelination is an established pathophysiological process in GBS, the rapid improvement of clinical deficits with treatment is consistent with Na⁺ channel blockade by antibodies or other circulating factors, such as cytokines. This review provides an update on the epidemiology, clinical features, diagnosis, pathogenesis and treatment of GBS.     

Anti-GD1a antibodies from an acute motor axonal neuropathy patient selectively bind to motor nerve fiber nodes of Ranvier.

Acute motor axonal neuropathy (AMAN) is associated with high titer anti-GD1a antibodies. We have found that very high titer IgG anti-GD1a antibodies (Ab) from one AMAN patient selectively bind to motor, but not sensory, nerve nodes of Ranvier. Binding is abolished by preadsorption with GD1a. Sera negative for Ab do not immunostain motor and sensory nerve roots. We have also found that botulinum toxin A (BTA), which binds to GD1a, stains both motor and sensory nerve nodes of Ranvier. Our results strongly support the pathogenetic role of anti-GD1a antibodies in AMAN. Why BTA also binds to sensory fibers still remains to be elucidated, although the different size of BTA and its specificity to other gangliosides present in sensory axons might represent important factors.     

Anti-GM1b IgG antibody is associated with acute motor axonal neuropathy and Campylobacter jejuni infection

Anti-GM1 and anti-GM1b antibodies are frequently present in patients with Guillain-Barré syndrome (GBS) and accordingly, the two antibodies often coexist in the same patient. In order to study clinical and laboratory features of anti-GM1b-positive GBS, we analyzed the data of patients with anti-GM1b IgG antibody but no anti-GM1 IgG antibody. Of 86 consecutive patients, 10 had anti-GM1b antibody alone and frequently had acute motor axonal neuropathy (AMAN, 80%) and Campylobacter jejuni infection (60%). Of 10 patients with anti-GM1 antibody alone, four had AMAN, and two had C. jejuni infection. These results showed that GM1b could be a target molecule of autoantibody in the AMAN form of GBS subsequent to C. jejuni infection.