IgM anti-GM2 antibodies in patients with multifocal motor neuropathy target Schwann cells and are associated with early onset

BACKGROUND

Multifocal motor neuropathy (MMN) is a rare, chronic immune-mediated polyneuropathy characterized by asymmetric distal limb weakness. An important feature of MMN is the presence of IgM antibodies against gangliosides, in particular GM1 and less often GM2. Antibodies against GM1 bind to motor neurons (MNs) and cause damage through complement activation. The involvement of Schwann cells (SCs), expressing GM1 and GM2, in the pathogenesis of MMN is unknown.

METHODS

Combining the data of our 2007 and 2015 combined cross-sectional and follow-up studies in Dutch patients with MMN, we evaluated the presence of IgM antibodies against GM1 and GM2 in serum from 124 patients with MMN and investigated their binding to SCs and complement-activating properties. We also assessed the relation of IgM binding and complement deposition with clinical characteristics.

RESULTS

Thirteen out of 124 patients (10%) had a positive ELISA titer for IgM anti-GM2. Age at onset of symptoms was significantly lower in MMN patients with anti-GM2 IgM. IgM binding to SCs correlated with IgM anti-GM2 titers. We found no correlation between IgM anti-GM2 titers and MN binding or with IgM anti-GM1 titers. IgM binding to SCs decreased upon pre-incubation of serum with soluble GM2, but not with soluble GM1. IgM anti-GM2 binding to SCs correlated with complement activation, as reflected by increased C3 fixation on SCs and C5a formation in the supernatant.

CONCLUSION

Circulating IgM anti-GM2 antibodies define a subgroup of patients with MMN that has an earlier onset of disease. These antibodies probably target SCs specifically and activate complement, similarly as IgM anti-GM1 on MNs. Our data indicate that complement activation by IgM antibodies bound to SCs and MNs underlies MMN pathology.

Cell density-dependent membrane distribution of ganglioside GM3 in melanoma cells

Monosialoganglioside GM3 is the simplest ganglioside involved in various cellular signaling. Cell surface distribution of GM3 is thought to be crucial for the function of GM3, but little is known about the cell surface GM3 distribution. It was shown that anti-GM3 monoclonal antibody binds to GM3 in sparse but not in confluent melanoma cells. Our model membrane study evidenced that monoclonal anti-GM3 antibodies showed stronger binding when GM3 was in less fluid membrane environment. Studies using fluorescent GM3 analogs suggested that GM3 was clustered in less fluid membrane. Moreover, fluorescent lifetime measurement showed that cell surface of high density melanoma cells is more fluid than that of low density cells. Lipidomics and fatty acid supplementation experiment suggested that monounsaturated fatty acid-containing phosphatidylcholine contributed to the cell density-dependent membrane fluidity. Our results indicate that anti-GM3 antibody senses GM3 clustering and the number and/or size of GM3 cluster differ between sparse and confluent melanoma cells.

Co-occurrence of polyneuritis crainials and visual impairment: a case report and literature review

BACKGROUND

Polyneuritis cranialis (PNC) with the disease characteristics of Guillain-Barré syndrome (GBS) in addition to both ocular and bulbar weakness in the absence of limb paralysis or ataxia is defined as an unusual variant of GBS. As evidence of central nervous system (CNS) involvement, visual impairment is an unusual finding complicating with GBS spectrum disorders and has never been reported in patients with PNC.

METHODS

We describe a very rare case who clinically presented with progressive multiple cranial nerve palsy and visual impairment. Furthermore, a literature search of concurrent GBS and optic neuritis (ON) as well as PNC attributed to GBS was conducted.

RESULTS

A diagnosis of PNC was considered due to the typical clinical characteristics as well as the presence of cerebrospinal fluid cytoalbumin dissociation and serum antibodies against gangliosides. The clinical manifestations and the bilateral optic nerve involvement in brain magnetic resonance imaging further suggested possible optic neuritis (ON). The patient received treatment with intravenous immunoglobulin followed by short-term use of corticosteroids and finally achieved a full recovery. Thirty-two previously reported cases (17 women, mean age 40) of concurrent GBS and ON and 20 cases of PNC (5 women, mean age 40) were analyzed. We further provided a comprehensive discussion on the potential etiologies, clinical features, therapeutic strategies, and prognosis.

CONCLUSIONS

This rare case with the co-occurrence of PNC and visual impairment and the related literature review may help clinicians advance the understanding of GBS spectrum disorders and make appropriate diagnoses and treatment decisions for the rare variants and CNS complications of GBS.

Guillain-Barré Syndrome in Mexico: An Updated Review Amid the Coronavirus Disease 2019 ERA

Guillain-Barré syndrome (GBS) is the most frequent cause of acute flaccid paralysis and if not diagnosed and treated timely, a significant cause of long-term disability. Incidence in Latin America ranges from 0.71 to 7.63 cases/100,000 person-years. Historically, GBS has been linked to infections (mainly gastrointestinal by Campylobacter jejuni) and vaccines (including those against severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]); however, a trigger cannot be detected in most cases. Regarding SARS-CoV-2, epidemiological studies have found no association with its development. Acute motor axonal neuropathy is the most common electrophysiological variant in Mexico and Asian countries. Intravenous immunoglobulin or plasma exchanges are still the treatment cornerstones. Mortality in Mexico can be as high as 12%. Avances in understanding the drivers of nerve injury in GBS that may provide the basis for developing targeted therapies have been made during the past decade; despite them, accurate criteria for selecting patients requiring acute treatment, prognostic biomarkers, and novel therapies are still needed. The newly-developed vaccines against SARS-CoV-2 have raised concerns regarding the potential risk for developing GBS. In the midst of coronavirus disease 2019 and vaccination campaigns against SARS-CoV-2, this review discusses the epidemiology, clinical presentation, management, and outcomes of GBS in Mexico.

Clinical and antibodies analysis of anti-GQ1b antibody syndrome: a case series of 15 patients

Objectives

To investigate the clinical manifestations, immunity, laboratory test, treatment and prognosis of patients with anti-GQ1b antibody syndrome in Chongqing, China.

Methods

We reviewed 15 patients with positive anti-ganglioside antibodies in the First Affiliated Hospital of Chongqing Medical University from 2016 to 2019.

Results

Fifteen patients were included in the study (mean age, 54.4 years; age range, 27 to 80 years; 9 men (60%)). Ten patients presented with a history of preinfection, including flu-like syndrome (n = 6, 60%), upper respiratory tract infection (URTI) (n = 3, 30%), and digestive tract infection (GI) (n = 1, 10%). The most common manifestation was ophthalmoplegia (n = 13, 86.67%), followed by weakness (n = 12, 80%), ataxia (n = 11, 73.3%), paresthesia (n = 8, 53.33%) and hypersomnolence (n = 5, 33.33%). All 15 patients underwent antibody testing. Eight patients (53.33%, 7 men (87.5%)) of whom only have positive immunoglobulin G (IgG) against anti-GQ1b antibody while seven (46.67%, 2 men (28.57%)) were positive for multiple anti-ganglioside antibodies apart from anti-GQ1b antibodies. Nine patients (60%) received intravenous immunoglobulin (IVIG) therapy, four (26.67%) received plasma exchange (PE) and two (13.33%) received steroid therapy. Three patients were lost to follow-up at 6 months, 1 patient (6.67%) had persistent back numbness, and the other 11 patients (73.33%) had fully recovered.

Conclusion

The clinical subtype of anti-GQ1b antibody syndrome correlates with the type of anti-ganglioside antibody. Patients who test positive for only anti-GQ1b antibody are more likely to be men. Most patients exhibit a unidirectional course with a good prognosis, but anti-GQ1b antibody syndrome is also associated with a risk of recurrence.

Campylobacter coli infection causes spinal epidural abscess with Guillain-Barré syndrome: a case report

Background

Guillain–Barré syndrome (GBS) and spinal epidural abscess (SEA) are known as mimics of each other because they present with flaccid paralysis following an infection; however, they differ in the main causative bacteria. Nevertheless, the two diseases can occur simultaneously if there is a preceding Campylobacter infection. Here, we report the first case of SEA with GBS following Campylobacter coli infection.

Case presentation

A 71-year-old Japanese man presented with progressive back pain and paralysis of the lower limbs following enteritis. Magnetic resonance imaging showed a lumbar epidural abscess that required surgical decompression; therefore, surgical drainage was performed. Blood cultures revealed the presence of C. coli. Despite surgery, the paralysis progressed to the extremities. Nerve conduction studies led to the diagnosis of GBS. Anti-ganglioside antibodies in the patient suggested that GBS was preceded by Campylobacter infection. Intravascular immunoglobulin therapy attenuated the progression of the paralysis.

Conclusions

We report a case of SEA and GBS following Campylobacter infection. A combination of the two diseases is rare; however, it could occur if the preceding infection is caused by Campylobacter spp. If a cause is known but the patient does not respond to the corresponding treatment, it is important to reconsider the diagnosis based on the medical history.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02537-6.

Immune mechanisms, the role of complement, and related therapies in autoimmune neuropathies

INTRODUCTION

Autoimmune neuropathies have diverse presentations and underlying immune mechanisms. Demonstration of efficacy of therapeutic agents that inhibit the complement cascade would confirm the role of complement activation.

AREAS COVERED

A review of the pathophysiology of the autoimmune neuropathies, to identify those that are likely to be complement mediated.

EXPERT OPINION

Complement mediated mechanisms are implicated in the acute and chronic neuropathies associated with IgG or IgM antibodies that target the Myelin Associated Glycoprotein (MAG) or gangliosides in the peripheral nerves. Antibody and complement mechanisms are also suspected in the Guillain-Barré syndrome and chronic inflammatory demyelinating neuropathy, given the therapeutic response to plasmapheresis or intravenous immunoglobulins, even in the absence of an identifiable target antigen. Complement is unlikely to play a role in paraneoplastic sensory neuropathy associated with antibodies to HU/ANNA-1 given its intracellular localization. In chronic demyelinating neuropathy with anti-nodal/paranodal CNTN1, NFS-155, and CASPR1 antibodies, myotonia with anti-VGKC LGI1 or CASPR2 antibodies, or autoimmune autonomic neuropathy with anti-gAChR antibodies, the response to complement inhibitory agents would depend on the extent to which the antibodies exert their effects through complement dependent or independent mechanisms. Complement is also likely to play a role in Sjogren's, vasculitic, and cryoglobulinemic neuropathies.

A Hypopituitarism Patient with Bickerstaff's Brainstem Encephalitis Overlapped by Guillain-Barré Syndrome: A Case Report

We present a rare case of Bickerstaff's brainstem encephalitis (BBE) overlapped with Guillain-Barré syndrome (GBS), which might be triggered by the patient's hypopituitarism condition. A 36-year-old woman with a history of hypopituitarism presented with a headache on the first day. Gradually, diplopia, ataxia, dysarthria, dysphagia, hypoesthesia, limb weakness, hypersomnolence, and respiratory muscle paralysis were developed in less than ten days. Based on brain computed tomography scan, magnetic resonance imaging scan, nerve conduction studies, cerebrospinal fluids analysis, anti-ganglioside antibodies and hormones tests, and clinical investigations, we diagnosed the patient with BBE overlapped with GBS. Treatment with corticosteroids and immunoglobulin resulted in clinical improvement. To our knowledge, this is the first case report of a hypopituitarism patient with BBE overlapped by GBS in English literature. Hypopituitarism patients have immune dysfunction. Based on previously reported autoimmune diseases associated with triggering GBS and its subtypes, hypopituitarism could be considered a noninfectious trigger.

Recurrent Miller-Fisher syndrome overlapping Guillain-Barrè syndrome and Bickerstaff brainstem encephalitis: A case report

Miller-Fisher syndrome (MFS) together with Guillan-Barré syndrome (GBS) and Bickerstaff brainstem encephalitis (BBE) are considered to form a continuous clinical spectrum of the same disease, possibly affecting the peripheral and/or central nervous systems, with monophasic symptoms. The frequency of overlapping clinical signs and the risk of recurrence are independent and very low, but no cases of GQ1b-seropositive recurrent MFS overlapping with GBS and BBE have been described so far. Here, we describe for the first time an atypical case of recurrent GQ1b-seropositive MFS overlapping GBS and BBE, 12 years after a previous GQ1b-seronegative typical MFS episode. Our case expands the clinical spectrum of recurrent MFS, and it should prompt clinicians to investigate the presence of anti-ganglioside antibodies in recurrent MFS even when these were negative in the previous episode, especially in those presenting with overlapping spectrum symptoms and a critically ill picture during the second episode.

High-resolution mapping identifies HLA class II associations with multifocal motor neuropathy

OBJECTIVE

To gain further insight in the immunopathology underlying multifocal motor neuropathy (MMN) by exploring the association between MMN and the human leukocyte antigen (HLA) class II DRB1, DQB1, and DQA loci in depth and by correlating associated haplotypes to detailed clinical and anti-ganglioside antibody data.

METHODS

We performed high-resolution HLA-class II typing for the DRB1, DQB1, and DQA1 loci in 126 well-characterized MMN patients and assessed disease associations with haplotypes. We used a cohort of 1305 random individuals as a reference for haplotype distribution in the Dutch population.

RESULTS

The DRB1*15:01-DQB1*06:02 haplotype (OR 1.6 [95% CI 1.1-2.2], p < 0.05) and the DRB1*12:01-DQB1*03:01 haplotype (OR 2.7 [95% CI 1.2-5.5], p < 0.05) were more frequent in patients with MMN than in controls. These haplotypes were not associated with disease course, response to treatment or anti-ganglioside antibodies.

CONCLUSIONS

MMN is associated with the DRB1*15:01-DQB1*06:02 and DRB1*12:01-DQB1*03:01 haplotypes. These HLA molecules or gene variants in their immediate vicinity may promote the specific inflammatory processes underlying MMN.

Antibodies to Zika virus, Campylobacter jejuni and gangliosides in Guillain-Barre syndrome: A prospective single-center study from southern India

Background

The objective of this article was to study the presence of antibodies against Zika virus (ZIKV), Campylobacter jejuni, and gangliosides in patients with Guillain-Barre syndrome (GBS).

Materials and Methods

Ninety consecutive patients (age more than 12 years) with GBS admitted to a tertiary care center in southern India were included in this study. Data on clinical manifestations, nerve conduction studies, and response to therapy were collected. The following tests were done in stored serum samples - anti-ZIKV (IgM) antibodies, anti-C. jejuni (IgG) antibodies, and anti-ganglioside antibodies (IgG). Those samples which were positive to anti-Zika antibodies were tested for conventional polymerase chain reaction for ZIKV and IgM antibodies against dengue, and Japanese encephalitis virus.

Results

Of the 90 patients, 3 died and 8 had persistent weakness. Acute inflammatory demyelinating polyradiculoneuropathy was the most common type of GBS (56.7%). Anti-ganglioside antibodies were present in 62.2% patients with GT1b being the most common. Anti-C. jejuni antibodies were present in 46.6%. Anti-Zika antibodies (IgM) were present in 14 patients (15.5%). Four of these patients also had anti-dengue antibody (IgM) positivity.

Conclusion

This is one of the largest studies on GBS from India and the first one to report on the presence of Zika virus antibodies from this geographical area. Our study had a high prevalence of anti-C. jejuni and anti-ganglioside antibodies. Evidence of recent ZIKV infection, as evidenced by anti-IgM antibodies, was present in 14 patients, with 4 of them being tested positive for anti-dengue IgM antibody. Whether this represents cross-reaction with dengue or prior/co-infection with dengue virus could not be addressed in this study.

Changes of Serum IgG Dimer Levels after Treatment with IVIg in Guillain-Barré Syndrome

Intravenous immunoglobulins (IVIg) are standard treatment for Guillain-Barré syndrome (GBS). Their exact mechanisms of action are versatile and not fully understood. One possible mechanism is neutralization of circulating autoantibodies via binding to anti- idiotypic antibodies forming idiotype-anti-idiotype dimeric IgG immune complexes. To examine the role of immune complex formation as mechanism of action for IVIg in GBS, 34 C57Bl/6 mice were either treated with anti-ganglioside antibodies and IVIg or IVIg and PBS alone, whereas eight additional mice were treated either with anti-ganglioside autoantibodies and IVIg or anti-ganglioside autoantibodies alone. Subsequently IgG dimer formation was assessed by high performance liquid chromatography (HPLC) and enzyme- linked immunosorbent assay (ELISA). In addition, IgG dimer formation was measured in sera of eight GBS patients who were treated with IVIg. In mice, a significant increase of dimeric IgG after administration of anti-ganglioside antibodies and IVIg could be observed. Re-monomerized IgG dimers showed immunoreactivity against gangliosides and serum immunoreactivity was significantly reduced after IVIg infusion. Likewise also in GBS patients, IgG dimer formation could be detected after IVIg treatment. Our data indicate that dimeric IgG immune complexes contain anti-idiotypic antibodies and provide proof of concept that IVIg treatment in GBS results in measurable amounts of IgG dimers. Larger patient cohorts are needed to evaluate serum IgG dimer increase as a possible marker for treatment response in GBS. Graphical Abstract Mechanism of action: Intravenous immunoglobulins (IVIg) and anti-ganglioside antibodies form dimeric IgG immune complexes, preventing axonal damage in Guillain-Barré Syndrome.

Sialic acid and anti-ganglioside antibody levels in children with autism spectrum disorders

BACKGROUND

Autism spectrum disorders (ASD) may result from a combination of genetic and environmental factors, and impact neurological functions and behaviors. Sialic acid (SA) is an indispensable nutrient for early brain development, and its polymer polySia (PSA) can modify neural cell adhesion molecules (NCAM), thereby indirectly mediating neuronal outgrowth, synaptic connectivity and memory formation. To investigate the association between SA and ASD, we conducted a case-control study.

METHODS

The study sample included 82 autistic children and 60 healthy children. We measured the levels of plasma SA and serum anti-gangliosides M1 antibodies (anti-GM1 antibodies) in the ASD and control groups. We also examined the severity of autistic children.

RESULTS

The level of plasma SA in the control group was significantly higher than that in the ASD group (p < .01). Autistic children had higher positive rates of anti-GM1 antibodies (37.8%) than controls (21.67%, P = .04). However, there was no correlation between autistic severity and the levels of SA. SA may be as a biomarker for diagnosis of ASD with a positive predictive value of 84.42%, a negative predictive value of 73.85% and an area under the ROC curve value of 0.858.

CONCLUSIONS

These results indicate that SA and anti-GM1 antibodies are associated with ASD. Our data suggested that future studies to explore the function of SA in the etiology of ASD may be needed.

The Role of Botulinum Toxin in the Management of Ophthalmoplegia Secondary to Miller Fisher Syndrome

Miller Fisher syndrome is an acute demyelinating polyneuropathy classically presenting with ataxia, areflexia, and ophthalmoplegia. The authors report the case of a 27-year-old female, who presented with limb weakness and double vision following a prodromal pharyngitis. Ophthalmic examination revealed fluctuant ophthalmoplegia eventually consistent with bilateral sixth cranial nerve palsies, prompting investigation for anti-ganglioside antibodies, which returned positive. Due to disabling diplopia, the patient was treated with botulinum toxin, with a resulting favourable reduction in the size of strabismus. Four months following her presentation, the patient was orthophoric and resumed normal activities.

Experimental Guillain-Barre syndrome induced by immunization with gangliosides: Keyhole limpet hemocyanin is required for disease triggering

An experimental model of Guillain-Barré Syndrome has been established in recent years. Rabbits develop disease upon immunization with a single dose of an emulsion containing bovine brain gangliosides, KLH and complete Freund's adjuvant. Within a period of four to ten weeks after immunization, they began to produce anti-ganglioside IgG-antibodies first, and to show clinical signs of neuropathy afterwards. In addition to gangliosides, KLH is a requirement for antibody production and disease triggering. Although KLH is commonly used as an immunological carrier protein, an anti-KLH-specific immune response was necessary for induction of both events. KLH is a glycoprotein carrying most of the immunogenicity in its glycan moiety. Between 20% to 80% of anti-ganglioside IgG-antibodies present in sick rabbit sera cross-reacted with KLH, indicating that both immune responses are related. The terminal Gal-ß(1,3)-GalNAc glycan (present in gangliosides and KLH) is proposed as "key" antigenic determinant involved in inducing the anti-ganglioside immune response. These results are discussed in the context of the "binding site drift" hypothesis.

Autoantibodies against ganglioside GM3 are associated with narcolepsy-cataplexy developing after Pandemrix vaccination against 2009 pandemic H1N1 type influenza virus

Following the mass vaccinations against pandemic influenza A/H1N1 virus in 2009, a sudden increase in juvenile onset narcolepsy with cataplexy (NC) was detected in several European countries where AS03-adjuvanted Pandemrix vaccine had been used. NC is a chronic neurological disorder characterized by excessive daytime sleepiness and cataplexy. In human NC, the hypocretin-producing neurons in the hypothalamus or the hypocretin signaling pathway are destroyed by an autoimmune reaction. Both genetic (e.g. HLA-DQB1*0602) and environmental risk factors (e.g. Pandemrix) contribute to the disease development, but the underlying and the mediating immunological mechanisms are largely unknown. Influenza virus hemagglutinin is known to bind gangliosides, which serve as host cell virus receptors. Anti-ganglioside antibodies have previously been linked to various neurological disorders, like the Guillain-Barré syndrome which may develop after infection or vaccination. Because of these links we screened sera of NC patients and controls for IgG anti-ganglioside antibodies against 11 human brain gangliosides (GM1, GM2, GM3, GM4, GD1a, GD1b, GD2, GD3, GT1a, GT1b, GQ1b) and a sulfatide by using a line blot assay. Samples from 173 children and adolescents were analyzed: 48 with Pandemrix-associated NC, 20 with NC without Pandemrix association, 57 Pandemrix-vaccinated and 48 unvaccinated healthy children. We found that patients with Pandemrix-associated NC had more frequently (14.6%) anti-GM3 antibodies than vaccinated healthy controls (3.5%) (P = 0.047). Anti-GM3 antibodies were significantly associated with HLA-DQB1*0602 (P = 0.016) both in vaccinated NC patients and controls. In general, anti-ganglioside antibodies were more frequent in vaccinated (18.1%) than in unvaccinated (7.3%) individuals (P = 0.035). Our data suggest that autoimmunity against GM3 is a feature of Pandemrix-associated NC and that autoantibodies against gangliosides were induced by Pandemrix vaccination.

A case of paraneoplastic demyelinating motor polyneuropathy

Peripheral neuropathy is commonly accompanied by cancer but demyelinating ones are not commonly reported. We report the clinical, neurophysiological, and biological characteristics of an 82-year-old patient who presented with a demyelinating motor neuropathy and high titre of anti-ganglioside antibodies associated with oesophageal cancer. The neurological course worsened rapidly despite immunotherapy, leading to a bedridden status. We propose to suspect a paraneoplastic origin in older patients or when the clinical course progresses rapidly within a few weeks or months.