Antiglycolipid antibodies in Guillain-Barré and Fisher syndromes: discovery, current status and future perspective

Only anti-GM4 antibody positivity in a Chinese girl with overlapping MFS/GBS: a case report

BACKGROUND

Guillain-Barré syndrome (GBS), as the most common cause of acute flaccid paralysis worldwide, is considered a part of a clinical spectrum in which discrete, complete, or incomplete forms of GBS and overlapping syndromes lie on the basis of their clinical features. The term overlapping Miller Fisher syndrome (MFS)/GBS is used when patients with MFS also suffer from progressive motor weakness of the limbs. Anti-ganglioside GQ1b has been specifically associated with MFS and ophthalmoplegia.

CASE DESCRIPTION

Here, we report a Chinese girl who was diagnosed with overlapping MFS/GBS showing acute flaccid paralysis of all four limbs, sensory symptoms, cranial nerve dysfunction, autonomic involvement, ophthalmoplegia, and ataxia. She had high serum and cerebrospinal fluid titres of monospecific anti-GM4 IgG antibody instead of anti-GQ1b antibody in the acute phase.

CONCLUSION

Anti-GM4 antibodies usually coexist with other antiganglioside antibodies, leading to missed diagnoses. The findings of the present study show that antibodies to ganglioside GM4 may in overlapping MFS/GBS as the lone immunological factors.

Takotsubo cardiomyopathy in Guillain-Barré syndrome

BACKGROUND AND PURPOSE

Takotsubo cardiomyopathy (TCM) is a serious autonomic complication of Guillain-Barré syndrome (GBS). However, the association between TCM and GBS has not been investigated in detail. We investigated the characteristics of GBS patients with TCM (GBS-TCM).

METHODS

Clinical features and anti-ganglioside antibody between the GBS-TCM patients and 62 classical GBS patients without TCM as control patients were compared.

RESULTS

Eight GBS-TCM patients were identified, in whom TCM was diagnosed at a mean of 6.5 [range 3-42] days after the onset of GBS. The age at onset of GBS was elder in the GBS-TCM patients than in the control GBS patients (76.5 [56-87] vs. 52 [20-88] years, p < 0.01). Notably, cranial nerve deficits, particularly in the lower cranial nerves, were observed in all GBS-TCM patients (100% vs. 41.9%, p < 0.01). Additionally, the GBS-TCM patients showed a higher GBS disability score at nadir (5 [4-5] vs. 4 [1-5], p < 0.01), and lower Medical Research Council sum scores at admission and nadir (37 [30-44] vs. 48 [12-60] at admission, p < 0.05, and 20 [12-44] vs. 40 [0-60] at nadir, p < 0.05, respectively). Mechanical ventilation was more frequently required in the GBS-TCM patients (62.5% vs. 11.3%, p < 0.01). Three GBS-TCM patients were positive for anti-ganglioside antibodies.

CONCLUSIONS

TCM occurred at a relatively early phase of GBS. The characteristics of GBS-TCM were the elder, lower cranial nerve involvements, severe limb weakness, and respiratory failure.

Multifocal motor neuropathy is not associated with altered innate immune responses to endotoxin

OBJECTIVE

Antibody- and complement-mediated peripheral nerve inflammation are central in the pathogenesis of MMN. Here, we studied innate immune responses to endotoxin in patients with MMN and controls to further our understanding of MMN risk factors and disease modifiers.

METHODS

We stimulated whole blood of 52 patients with MMN and 24 controls with endotoxin and collected plasma. With a multiplex assay, we determined levels of the immunoregulating proteins IL-1RA, IL-1β, IL-6, IL-10, IL-21, TNF-α, IL-8 and CD40L in unstimulated and LPS-stimulated plasma. We compared baseline and stimulated protein levels between patients and controls and correlated concentrations to clinical parameters.

RESULTS

Protein level changes after stimulation were comparable between groups (p > 0.05). IL-1RA, IL-1β, IL-6 and IL-21 baseline concentrations showed a positive correlation with monthly IVIg dosage (all corrected p-values < 0.016). Patients with anti-GM1 IgM antibodies showed a more pronounced IL-21 increase after stimulation (p 0.048).

CONCLUSIONS

Altered endotoxin-induced innate immune responses are unlikely to be a susceptibility factor for MMN.

Characteristics of Guillain-Barré syndrome in super-elderly individuals

BACKGROUND

Japan has the world's largest super-aging population, and the number of elderly patients with various diseases is increasing. Herein, we reported the characteristics of super-elderly patients, aged over 80 years, with Guillain-Barré syndrome (GBS), a typical neuroimmune disease.

METHODS

During the period 2019-2021, 74 patients over the age of 80 years diagnosed with GBS at Kindai university were analyzed as the super-elderly group patients. The control group comprised 74 consecutive patients aged < 79 years, under the same conditions. GBS was diagnosed using Brighton diagnostic criteria. Electrophysiology was assessed using the Ho criteria.

RESULTS

The mean age was 83.5 years in the super-elderly group and 51.7 years in the control group. Prior infection was recognized in 50% of cases in the super-elderly group and 77% of cases in the control group with fewer cases in the super-elderly group. The mean number of days until peak symptom presentation was longer in the super-elderly group. The percentage who required a ventilator was significantly higher among the super-elderly group than among the control group. Hughes functional grading scale was more severe in the super-elderly group. Electrophysiological examination revealed the demyelinating form was particularly common in the super-elderly group. Intravenous immunoglobulin was the most common treatment in both the groups, with no difference in efficacy.

CONCLUSIONS

Super-elderly onset GBS tends to be severe, therefore it is important to diagnose and treat appropriately, even in the absence of prior episodes of infection.

Serum anti-GM2 and anti-GalNAc-GD1a ganglioside IgG antibodies are biomarkers for immune-mediated polyneuropathies in cats

Recent work identified anti-GM2 and anti-GalNAc-GD1a IgG ganglioside antibodies as biomarkers in dogs clinically diagnosed with acute canine polyradiculoneuritis, in turn considered a canine equivalent of Guillain-Barré syndrome. This study aims to investigate the serum prevalence of similar antibodies in cats clinically diagnosed with immune-mediated polyneuropathies. The sera from 41 cats clinically diagnosed with immune-mediated polyneuropathies (IPN), 9 cats with other neurological or neuromuscular disorders (ONM) and 46 neurologically normal cats (CTRL) were examined for the presence of IgG antibodies against glycolipids GM1, GM2, GD1a, GD1b, GalNAc-GD1a, GA1, SGPG, LM1, galactocerebroside and sulphatide. A total of 29/41 IPN-cats had either anti-GM2 or anti-GalNAc-GD1a IgG antibodies, with 24/29 cats having both. Direct comparison of anti-GM2 (sensitivity: 70.7%; specificity: 78.2%) and anti-GalNAc-GD1a (sensitivity: 70.7%; specificity: 70.9%) antibodies narrowly showed anti-GM2 IgG antibodies to be the better marker for identifying IPN-cats when compared to the combined ONM and CTRL groups (P = .049). Anti-GA1 and/or anti-sulphatide IgG antibodies were ubiquitously present across all sample groups, whereas antibodies against GM1, GD1a, GD1b, SGPG, LM1 and galactocerebroside were overall only rarely observed. Anti-GM2 and anti-GalNAc-GD1a IgG antibodies may serve as serum biomarkers for immune-mediated polyneuropathies in cats, as previously observed in dogs and humans.

Complement biomarkers reflect the pathological status of neuromyelitis optica spectrum disorders

Complement is involved in the pathogenesis of neuroimmune disease, but the detailed pathological roles of the complement pathway remain incompletely understood. Recently, eculizumab, a humanized anti-C5 monoclonal antibody, has been clinically applied against neuroimmune diseases such as myasthenia gravis and neuromyelitis optica spectrum disorders (NMOSD). Clinical application of eculizumab is also being investigated for another neuroimmune disease, Guillain-Barré syndrome (GBS). However, while the effectiveness of eculizumab for NMOSD is extremely high in many cases, there are some cases of myasthenia gravis and GBS in which eculizumab has little or no efficacy. Development of effective biomarkers that reflect complement activation in these diseases is therefore important. To identify biomarkers that could predict disease status, we retrospectively analyzed serum levels of complement factors in 21 patients with NMOSD and 25 patients with GBS. Ba, an activation marker of the alternative complement pathway, was elevated in the acute phases of both NMOSD and GBS. Meanwhile, sC5b-9, an activation marker generated by the terminal complement pathway, was elevated in NMOSD but not in GBS. Complement factor H (CFH), a complement regulatory factor, was decreased in the acute phase as well as in the remission phase of NMOSD, but not in any phases of GBS. Together, these findings suggest that complement biomarkers, such as Ba, sC5b-9 and CFH in peripheral blood, have potential utility in understanding the pathological status of NMOSD.

Sex differences in Guillain Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy and experimental autoimmune neuritis

Guillain Barré syndrome (GBS) and its variants, and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP and its variants, are regarded as immune mediated neuropathies. Unlike in many autoimmune disorders, GBS and CIDP are more common in males than females. Sex is not a clear predictor of outcome. Experimental autoimmune neuritis (EAN) is an animal model of these diseases, but there are no studies of the effects of sex in EAN. The pathogenesis of GBS and CIDP involves immune response to non-protein antigens, antigen presentation through non-conventional T cells and, in CIDP with nodopathy, IgG4 antibody responses to antigens. There are some reported sex differences in some of these elements of the immune system and we speculate that these sex differences could contribute to the male predominance of these diseases, and suggest that sex differences in peripheral nerves is a topic worthy of further study.

Guillain-Barré syndrome in children - High occurrence of Miller Fisher syndrome in East Asian region

BACKGROUND

Guillain-Barré syndrome (GBS) is a rare acquired immune-mediated polyneuropathy. Updated population-based data concerning paediatric GBS is needed.

METHODS

Paediatric patients aged below 18 years diagnosed with GBS between 2009 and 2018 in all 11 paediatric departments in Hong Kong were identified from the Hong Kong Hospital Authority Clinical Data Analysis and Reporting System. The collected data from medical health records were reviewed by paediatric neurologist from each department. Estimated incidence of paediatric GBS was calculated. We also compared our findings with other paediatric GBS studies in Asia.

RESULTS

63 subjects of paediatric GBS were identified, giving an estimated annual incidence of 0.62 per 100,000 population. Half of the subjects had acute inflammatory demyelinating polyneuropathy (AIDP) (n = 31; 49.2%), one quarter had Miller Fisher Syndrome (MFS) (n = 16; 25.4%), one-fifth had axonal types of GBS (n = 12; 19.0%), and four were unclassified. Paediatric subjects with axonal subtypes of GBS compared to the other 2 subtypes, had significantly higher intensive care unit (ICU) admission rates (p = 0.001) and longest length of stay (p = 0.009). With immunomodulating therapy, complete recovery was highest in those with MFS (100%), followed by AIDP (87.1%) and axonal GBS (75%). Our study also confirms a higher MFS rate for paediatric GBS in East Asia region and our study has the highest MFS rate (25.4%).

CONCLUSION

Our population-based 10-year paediatric GBS study provides updated evidence on estimated incidence, healthcare burden and motor outcome of each subtype of paediatric GBS and confirmed a higher occurrence of paediatric MFS in East Asia.

Downregulation of LKB1/AMPK Signaling in Blood Mononuclear Cells Is Associated with the Severity of Guillain-Barre Syndrome

AMP-activated protein kinase (AMPK) is an intracellular energy sensor that regulates metabolic and immune functions mainly through the inhibition of the mechanistic target of rapamycin (mTOR)-dependent anabolic pathways and the activation of catabolic processes such as autophagy. The AMPK/mTOR signaling pathway and autophagy markers were analyzed by immunoblotting in blood mononuclear cells of 20 healthy control subjects and 23 patients with an acute demyelinating form of Guillain–Barré syndrome (GBS). The activation of the liver kinase B1 (LKB1)/AMPK/Raptor signaling axis was significantly reduced in GBS compared to control subjects. In contrast, the phosphorylated forms of mTOR activator AKT and mTOR substrate 4EBP1, as well as the levels of autophagy markers LC3-II, beclin-1, ATG5, p62/sequestosome 1, and NBR1 were similar between the two groups. The downregulation of LKB1/AMPK signaling, but not the activation status of the AKT/mTOR/4EBP1 pathway or the levels of autophagy markers, correlated with higher clinical activity and worse outcomes of GBS. A retrospective study in a diabetic cohort of GBS patients demonstrated that treatment with AMPK activator metformin was associated with milder GBS compared to insulin/sulphonylurea therapy. In conclusion, the impairment of the LKB1/AMPK pathway might contribute to the development/progression of GBS, thus representing a potential therapeutic target in this immune-mediated peripheral polyneuropathy.

Experimental and computational characterization of dynamic biomolecular interaction systems involving glycolipid glycans

On cell surfaces, carbohydrate chains that modify proteins and lipids mediate various biological functions, which are exerted not only through carbohydrate-protein interactions but also through carbohydrate-carbohydrate interactions. These glycans exhibit considerable degrees of conformational variability and often form clusters providing multiple binding sites. The integration of nuclear magnetic resonance spectroscopy and molecular dynamics simulation has made it possible to delineate the dynamical structures of carbohydrate chains. This approach has facilitated the remodeling of oligosaccharide conformational space in the prebound state to improve protein-binding affinity and has been applied to visualize dynamic carbohydrate-carbohydrate interactions that control glycoprotein-glycoprotein complex formation. Functional glycoclusters have been characterized by experimental and computational approaches applied to various model membranes and artificial self-assembling systems. This line of investigation has provided dynamic views of molecular assembling on glycoclusters, giving mechanistic insights into physiological and pathological molecular events on cell surfaces as well as clues for the design and creation of molecular systems exerting improved glycofunctions. Further development and accumulation of such studies will allow detailed understanding and artificial control of the "glycosynapse" foreseen by Dr. Sen-itiroh Hakomori.

Serum anti-GM2 and anti-GalNAc-GD1a IgG antibodies are biomarkers for acute canine polyradiculoneuritis

OBJECTIVES

A previous single-country pilot study indicated serum anti-GM2 and anti-GA1 anti-glycolipid antibodies as potential biomarkers for acute canine polyradiculoneuritis. This study aims to validate these findings in a large geographically heterogenous cohort.

MATERIALS AND METHODS

Sera from 175 dogs clinically diagnosed with acute canine polyradiculoneuritis, 112 dogs with other peripheral nerve, cranial nerve or neuromuscular disorders and 226 neurologically normal dogs were screened for anti-glycolipid antibodies against 11 common glycolipid targets to determine the immunoglobulin G anti-glycolipid antibodies with the highest combined sensitivity and specificity for acute canine polyradiculoneuritis.

RESULTS

Anti-GM2 anti-glycolipid antibodies reached the highest combined sensitivity and specificity (sensitivity: 65.1%, 95% confidence interval 57.6 to 72.2%; specificity: 90.2%, 95% confidence interval 83.1 to 95.0%), followed by anti-GalNAc-GD1a anti-glycolipid antibodies (sensitivity: 61.7%, 95% confidence interval 54.1 to 68.9%; specificity: 89.3%, 95% confidence interval 82.0 to 94.3%) and these anti-glycolipid antibodies were frequently present concomitantly. Anti-GA1 anti-glycolipid antibodies were detected in both acute canine polyradiculoneuritis and control animals. Both for anti-GM2 and anti-GalNAc-GD1a anti-glycolipid antibodies, sex was found a significantly associated factor with a female to male odds ratio of 2.55 (1.27 to 5.31) and 3.00 (1.22 to 7.89), respectively. Anti-GalNAc-GD1a anti-glycolipid antibodies were more commonly observed in dogs unable to walk (OR 4.56, 1.56 to 14.87).

CLINICAL SIGNIFICANCE

Anti-GM2 and anti-GalNAc-GD1a immunoglobulin G anti-glycolipid antibodies represent serum biomarkers for acute canine polyradiculoneuritis.

Anti-ganglioside Antibodies in Guillain-Barre Syndrome: A Novel Immunoblotting-Panel Assay

Objective: This study aimed to determine the diagnostic efficiency of a novel immunoblotting detection assay for anti-ganglioside antibodies (AGAs) in the Guillain–Barre syndrome (GBS).

Method: Serum immunoglobulin (IgG and IgM) of AGAs were measured in 121 participants from a registered cohort study of immune-mediated neuropathies and 29 healthy controls by immunoblotting panel assay. Sensitivity, specificity, and positive predictive value (PPV) of the assay were compared to calculate the diagnostic accuracy.

Result: In our cohort, any of the AGAs were positive in 42.4% of the GBS patients. The sensitivity and specificity of AGAs (both IgG and IgM) in the diagnosis of GSB were 42 and 76% while for IgG-AGAs were 35 and 87%. AGAs positivity had a significant association with the AMAN subtype (P = 0.0004), and the sensitivity, specificity of AGAs in AMAN were 86, 69%, respectively with high (AUC = 0.78, p = 0.002) discriminative powers. GM1-IgG AGA was more common and specific to AMAN patients than other GBS forms (p = 0.008).

Conclusion: Our novel immunoblotting detection assay could complement GBS diagnosis. IgG-AGAs were more likely to be detected in GBS, and GM1-IgG AGA could assist AMAN diagnosis.