Binding of immunoglobulin G antibodies in Guillain-Barré syndrome sera to a mixture of GM1 and a phospholipid: possible clinical implications

Cholesterol-added antigens can enhance antiglycolipid antibody activity: Application to antibody testing

We analysed the effect of adding cholesterol to glycolipid antigens on antibody activity with enzyme-linked immunosorbent assay in 123 subjects consisting of 96 patients with Guillain-Barré syndrome, 25 Miller Fisher syndrome, and two Bickerstaff brainstem encephalitis. The use of cholesterol-added GM1 antigens increased anti-GM1 activity in 11 out of 23 anti-GM1-positive patients and resulted in six out of 100 anti-GM1-negative patients becoming anti-GM1-positive. Enhancement of anti-GM1 activity by cholesterol addition was significantly associated with antecedent gastrointestinal infection. The use of cholesterol-added glycolipid antigens can increase the detection rate of anti-glycolipid antibodies and accurately evaluate the anti-glycolipid antibody activity in vivo.

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

Guillain-Barré syndrome (GBS) and Fisher syndrome (FS) are acute autoimmune neuropathies, often preceded by an infection. Antiglycolipid antibody titres are frequently elevated in sera from the acute-phase patients. Particularly, IgG anti-GQ1b antibodies are positive in as high as 90% of FS cases and thus useful for diagnosis. The development of animal models of antiglycolipid antibody-mediated neuropathies proved that some of these antibodies are directly involved in the pathogenetic mechanisms by binding to the regions where the respective target glycolipid is specifically localised. Discovery of the presence of the antibodies that specifically recognise a new conformational epitope formed by two different gangliosides (ganglioside complex) in the acute-phase sera of some patients with GBS suggested the carbohydrate-carbohydrate interaction between glycolipids. This finding indicated the need for further research in basic glycobiological science. Antiglycolipid antibodies, in particular antigangliosides antibodies, are mostly detected in acute motor axonal neuropathy type of GBS and in FS, and less frequently in the acute inflammatory demyelinating polyneuropathy (AIDP) type of GBS or in central nervous system (CNS) diseases. In the future, the search for the putative antibodies in AIDP and those that might be present in CNS diseases should continue. In addition, more efficient standardisation of antiglycolipid antibody detection methods and use as biomarkers in daily clinical practice in neurology is needed.

Finger drop sign as a new variant of acute motor axonal neuropathy

We propose the finger drop sign as a new clinical variant of acute motor axonal neuropathy (AMAN) defined by immunological and radiological evidence. We identified eight consecutive patients who had AMAN. All of them developed prominent involvement of the finger extensors. We performed magnetic resonance imaging (MRI) of the extremity muscles and serological assays for antiganglioside antibodies and Campylobacter jejuni. Patients with AMAN showed characteristic and a markedly sustained weakness of the finger extensors with a distinctive pattern of the finger drop sign. Limb MRI revealed unevenly distributed abnormal signals in the muscles mainly innervated by the posterior interosseous nerve. All tested patients showed positivity for immunoglobulin G antibody against ganglioside complex of GM1 and phosphatidic acid. A pathophysiological understanding of this unique syndrome can provide further insight into antiganglioside-antibody-mediated axonal injury in Guillain-Barré syndrome.

Neurological Disorders Identified during Treatment of a SARS-CoV-2 Infection

A 69-year-old man was admitted to our hospital under diagnosis of pneumonia due to severe acute respiratory syndrome-corona virus 2 (SARS-CoV-2) (Day 0). He underwent endotracheal intubation from Day 3. Although his respiratory condition improved and anesthetic drugs were discontinued, no cough reflex was observed despite intubation having been performed until Day 17. His tendon reflexes were also diminished. We suspected that he had developed Guillain-Barré syndrome (GBS), and administered intravenous immunoglobulin from Day 18. The absence of cough reflex improved and extubation was successfully performed on Day 23. Neurological disorders including GBS should be considered when intubated SARS-CoV-2 patients present with a loss of cough reflex during the treatment period.

Clinical and neurophysiological characteristics of patients with Guillain-Barré syndrome at Hospital Universitario San Ignacio, Bogotá, Colombia between 2009 and 2017

Guillain-Barré syndrome (GBS) is the most common acute peripheral polyneuropathy in the world. The estimated incidence in Colombia is 1.2-1.7 cases per 100 000 inhabitants, although during 2016 an increase in the incidence of the disease was documented, apparently associated with an epidemiological peak of the Zika virus. We conducted to describe the clinical and neurophysiological characteristics of adult patients with GBS treated at Hospital Universitario San Ignacio, Bogota, Colombia, between 2009 and 2017. An observational, descriptive, cross-sectional study was designed.

Miller Fisher Syndrome Mimicking Tolosa-Hunt Syndrome

We herein report a patient with Miller Fisher syndrome mimicking Tolosa-Hunt syndrome. A 47-year-old man presented with right orbital pain and diplopia. On a neurological examination, he had right oculomotor nerve palsy and diminished deep tendon reflexes. Brain magnetic resonance imaging failed to show any parenchymal lesions; however, the bilateral oculomotor nerves were gadolinium-enhanced. The presence of a triad of orbital pain, ipsilateral oculomotor nerve palsy, and a rapid response to steroid therapy met the diagnostic criteria for Tolosa-Hunt syndrome. After discharge, antibodies against GQ1b and GT1a were reported to be positive only with phosphatidic acid. The present case was ultimately diagnosed as an incomplete phenotype of Miller Fisher syndrome.

Clinical Features of Acute Flaccid Myelitis Temporally Associated With an Enterovirus D68 Outbreak: Results of a Nationwide Survey of Acute Flaccid Paralysis in Japan, August-December 2015

Background

Acute flaccid myelitis (AFM) is an acute flaccid paralysis syndrome with spinal motor neuron involvement of unknown etiology. We investigated the characteristics and prognostic factors of AFM clusters coincident with an enterovirus D68 (EV-D68) outbreak in Japan during autumn 2015.

Methods

An AFM case series study was conducted following a nationwide survey from August to December 2015. Radiographic and neurophysiologic data were subjected to centralized review, and virology studies were conducted for available specimens.

Results

Fifty-nine AFM cases (58 definite, 1 probable) were identified, including 55 children and 4 adults (median age, 4.4 years). The AFM epidemic curve showed strong temporal correlation with EV-D68 detection from pathogen surveillance, but not with other pathogens. EV-D68 was detected in 9 patients: 5 in nasopharyngeal, 2 in stool, 1 in cerebrospinal fluid (adult case), and 1 in tracheal aspiration, nasopharyngeal, and serum samples (a pediatric case with preceding steroid usage). Cases exhibited heterogeneous paralysis patterns from 1- to 4-limb involvement, but all definite cases had longitudinal spinal gray matter lesions on magnetic resonance imaging (median, 20 spinal segments). Cerebrospinal fluid pleocytosis was observed in 50 of 59 cases (85%), and 8 of 29 (28%) were positive for antiganglioside antibodies, as frequently observed in Guillain-Barré syndrome. Fifty-two patients showed variable residual weakness at follow-up. Good prognostic factors included a pretreatment manual muscle strength test unit score >3, normal F-wave persistence, and EV-D68-negative status.

Conclusions

EV-D68 may be one of the causative agents for AFM, while host susceptibility factors such as immune response could contribute to AFM development.

Guillain-Barré Syndrome: A Variant Consisting of Facial Diplegia and Paresthesia with Left Facial Hemiplegia Associated with Antibodies to Galactocerebroside and Phosphatidic Acid

BACKGROUND A rare variant of Guillain-Barré syndrome (GBS) consists of facial diplegia and paresthesia, but an even more rare association is with facial hemiplegia, similar to Bell's palsy. This case report is of this rare variant of GBS that was associated with IgG antibodies to galactocerebroside and phosphatidic acid. CASE REPORT A 54-year-old man presented with lower left facial palsy and paresthesia of his extremities, following an upper respiratory tract infection. Physical examination confirmed lower left facial palsy and paresthesia of his extremities with hyporeflexia of his lower limbs and sensory loss of all four extremities. The differential diagnosis was between a variant of GBS and Bell's palsy. Following initial treatment with glucocorticoids followed by intravenous immunoglobulin (IVIG), his sensory abnormalities resolved. Serum IgG antibodies to galactocerebroside and phosphatidic acid were positive in this patient, but not other antibodies to glycolipids or phospholipids were found. Five months following discharge from hospital, his left facial palsy had improved. CONCLUSIONS A case of a rare variant of GBS is presented with facial diplegia and paresthesia and with unilateral facial palsy. This rare variant of GBS may which may mimic Bell's palsy. In this case, IgG antibodies to galactocerebroside and phosphatidic acid were detected.

A case of acute autonomic and sensory neuropathy (AASN) with antibody against a mixture of galactocerebroside and phospholipids

A 62-year-old woman presented with paresthesia of limbs, gait disturbance, urinary retention and constipation following upper respiratory infection. Neurological examination revealed gait disturbance due to loss of position sense in her extremities with intact muscle power, and autonomic failure represented by orthostatic hypotension, constipation and autonomic bladder. Cerebrospinal fluid analysis showed normal cell counts with elevated protein levels. Nerve conduction study showed sensory nerve impairment with almost normal motor nerve conduction in her upper and lower extremities. Sympathetic skin response of both hands was unresponsive, indicating autonomic nervous dysfunction. We diagnosed her as having acute autonomic and sensory neuropathy (AASN) and treated her with intravenous immunoglobulin, which ameliorated her symptoms enabling her to walk without any assistance at the time of discharge. Screening tests of serum autoantibodies revealed positivity of antibody against a mixture of galactocerebroside (Gal-Cer) and phospholipids. According to previous literature, no specific antibodies have been identified in AASN. This case, therefore, suggests a possible role of anti-Gal-Cer antibody in the pathogenesis of AASN.

Ca(2+)-dependent anti-GQ1b antibody in GQ1b-seronegative Fisher syndrome and related disorders

Although serum IgG anti-ganglioside GQ1b antibody is the most specific biomarker for Fisher syndrome and its related disorders (FS-RD), 10%-30% of the patients are still negative in conventional assays ("GQ1b-seronegative") and the relationship between GQ1b-seropositive and -seronegative patients has been unclear. Some molecules require Ca(2+) cations to interact with their ligands (Ca(2+)-dependency). Here we have investigated whether Ca(2+)-dependency is also present in anti-GQ1b antibodies in FS-RD, especially in the GQ1b-seronegative patients and show that IgG antibodies against GQ1b-related antigens (isolated GQ1b and GQ1b-containing complexes) are detected Ca(2+)-dependently in the majority of GQ1b-seronegative patients with FS-RD. The Ca(2+)-dependent antibodies might react specifically with GQ1b-Ca(2+) conformation. This is the first demonstration of disease-related Ca(2+)-dependent antibodies in neurological field. GQ1b-related pathology would be involved in FS-RD more extensively than previously revealed.

Sonographic evaluation of peripheral nerves in subtypes of Guillain-Barré syndrome

BACKGROUND

Sonography of peripheral nerves can depict alteration of nerve sizes that could reflect inflammation and edema in inflammatory and demyelinating neuropathies. Guillain-Barré syndrome (GBS). Information on sonographic comparison of an axonal subtype (acute motor [and sensory] axonal neuropathy [AMAN and AMSAN]) and a demyelinating subtype (acute inflammatory demyelinating polyneuropathy [AIDP]) has been sparse.

MATERIAL AND METHODS

Sonography of peripheral nerves and cervical nerve roots were prospectively recorded in patients with GBS who were within three weeks of disease onset.

RESULTS

Five patients with AIDP and nine with AMAN (n=6)/AMSAN (n=3) were enrolled. The patients with AIDP showed evidence of greater degrees of demyelination (e.g., slower conduction velocities and increased distal latencies) than those with AMAN/AMSAN. The patients with AIDP tended to show enlarged nerves in the proximal segments and in the cervical roots, whereas the patients with AMAN/AMSAN had greater enlargement in the distal neve segment, especially in the median nerve (P = 0.03; Wrist-axilla cross-sectional ratio).

CONCLUSION

In this small study, two subtypes of GBS showed different patterns of involvement that might reflect different pathomechanisms.

Acute pan-dysautonomia as well as central nervous system involvement and peripheral neuropathies in a patient with systemic lupus erythematosus

A 32-year-old woman was diagnosed with leucopenia in 2002, being antinuclear antibody, anti-DNA antibody, and antiphospholipid antibody positive, and she was administered low-dose aspirin. In July 2006, she was admitted to our hospital because of pyrexia and abdominal pain. Examination revealed paralytic ileus, absence of the pupillary light reflex, dyshidrosis and anuresis. In addition, with high-level interleukin-6 in cerebrospinal fluid, the sensory nerve conduction velocity was derivation impotence. She was subsequently diagnosed with systemic lupus erythematosus (SLE) with central nervous system involvement, peripheral neuropathy as well as acute pan-dysautonomia. After pulse corticosteroid therapy, paralytic ileus was improved, however, the urination disorder persisted, and syncope due to orthostatic hypotension became marked. Plasma exchange and a second course of pulse corticosteroid therapy were performed, and were ineffective, whereas intravenous cyclophosphamide was effective. This patient is a rare case of central nervous system, peripheral neuropathy as well as acute pan-dysautonomia with SLE.

Anti-ganglioside complex antibodies associated with severe disability in GBS

Ganglioside complexes (GSCs) are known as target antigens in Guillain-Barré syndrome (GBS). To elucidate the clinical importance of the anti-GSC antibodies in GBS, we investigated serum antibodies to GSCs containing two of the gangliosides, GM1, GD1a, GD1b and GT1b, and analyzed clinical features of anti-GSC-positive GBS patients. Thirty-nine (17%) of 234 GBS patients had IgG anti-GSC antibodies. Anti-GSC-positive GBS had antecedent gastrointestinal infection and lower cranial nerve deficits more frequently than control GBS. The presence of antibody specificity to GD1a/GD1b and/or GD1b/GT1b was significantly associated with severe disability and a requirement for mechanical ventilation.

Guillain-Barré syndrome

Guillain-Barré syndrome consists of at least four subtypes of acute peripheral neuropathy. Major advances have been made in understanding the mechanisms of some of the subtypes. The histological appearance of the acute inflammatory demyelinating polyradiculoneuropathy (AIDP) subtype resembles experimental autoimmune neuritis, which is predominantly caused by T cells directed against peptides from the myelin proteins P0, P2, and PMP22. The role of T-cell-mediated immunity in AIDP remains unclear and there is evidence for the involvement of antibodies and complement. Strong evidence now exists that axonal subtypes of Guillain-Barré syndrome, acute motor axonal neuropathy (AMAN), and acute motor and sensory axonal neuropathy (AMSAN), are caused by antibodies to gangliosides on the axolemma that target macrophages to invade the axon at the node of Ranvier. About a quarter of patients with Guillain-Barré syndrome have had a recent Campylobacter jejuni infection, and axonal forms of the disease are especially common in these people. The lipo-oligosaccharide from the C jejuni bacterial wall contains ganglioside-like structures and its injection into rabbits induces a neuropathy that resembles acute motor axonal neuropathy. Antibodies to GM1, GM1b, GD1a, and GalNac-GD1a are in particular implicated in acute motor axonal neuropathy and, with the exception of GalNacGD1a, in acute motor and sensory axonal neuropathy. The Fisher's syndrome subtype is especially associated with antibodies to GQ1b, and similar cross-reactivity with ganglioside structures in the wall of C jejuni has been discovered. Anti-GQ1b antibodies have been shown to damage the motor nerve terminal in vitro by a complement-mediated mechanism. Results of international randomised trials have shown equivalent efficacy of both plasma exchange and intravenous immunoglobulin, but not corticosteroids, in hastening recovery from Guillain-Barré syndrome. Further research is needed to discover treatments to prevent 20% of patients from being left with persistent and significant disability.

Antibodies induced by ganglioside-mimicking Campylobacter jejuni lipooligosaccharides recognise epitopes at the nodes of Ranvier

Molecular mimicry of gangliosides by Campylobacter jejuni lipooligosaccharides (LOSs) in the induction of anti-ganglioside antibodies has been hypothesised to contribute to GBS development. Rabbits were immunised with ganglioside-mimicking C. jejuni LOSs and anti-LOS responses were analysed using passive haemagglutination, and anti-ganglioside responses by enzyme-linked immunosorbent assay and thin-layer chromatography with immunostaining. High titres of anti-LOS antibodies were demonstrated in rabbit antisera that were cross-reactive with a panel of gangliosides. Non-ganglioside-mimicking C. jejuni HS:3 LOS induced a strong anti-LOS response, but no anti-ganglioside antibodies. Control rabbit antisera had no anti-LOS or -ganglioside responses. Moreover, IgG from a patient treated with parenteral gangliosides, who exhibited Guillain-Barré syndrome, had antibodies reactive with C. jejuni LOS. Biotinylated IgG fractions from the rabbit and the patient sera recognised epitopes at the nodes of Ranvier in sectioned human nerves, whereas fractions from controls did not. This study demonstrates that immunisation with ganglioside-mimicking C. jejuni LOS triggers the production of cross-reactive anti-ganglioside antibodies that recognise epitopes at the nodes of Ranvier.

Effects of phospholipids on antiganglioside antibody reactivity in GBS

Serum antibody activities to mixtures of a ganglioside and various phospholipids were compared with those to a ganglioside alone in 30 anti-GM1 IgG-positive GBS patients and 30 anti-GQ1b IgG-positive Miller Fisher syndrome (MFS) patients. Anti-GM1-positive sera had higher antibody reactivities against a mixture of GM1 and several phospholipids including PA, PI and PS, than against GM1 alone. In contrast, in case of anti-GQ1b antibody, no phospholipid provided significant enhancement. Sphingomyelin provided decrease of the activity for both anti-GM1 and anti-GQ1b IgG. The effects of phospholipids must be considered to determine the pathogenetic role of antiganglioside antibodies in GBS and MFS.