Guillain-Barré syndrome with IgM antibody to the ganglioside GalNAc-GD1a

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.

[A case of neuralgic amyotrophy with extension disturbance of fingers after Cushing's syndrome remission]

We describe a 57-year-old female patient who experienced hypercortisolemia caused by adrenal Cushing's syndrome. Two months post-adrenalectomy, she developed acute severe bilateral pain starting in her fingers and spreading up her arms. In the subsequent two weeks, the patient presented upper extremity patchy paralysis with extension disturbance of fingers. In the following two months, she experienced atrophy of the muscles in the hands and joint contracture. Consequently, we diagnosed her with neuralgic amyotrophy. Nerve conduction studies showed low compound muscle action potential of all the peripheral nerves in the forearms, suggesting motor neuron axonopathy. Gadolinium-enhanced MRI and ultrasound studies did not reveal any abnormalities in the brachial plexus and peripheral nerves of the forearms. The patient tested positive for anti-GalNAc-GD1a-IgM antibodies and received intravenous immunoglobulin 6 months after the onset of symptoms, which resulted in reduction of pain, muscle weakness, and contractures. This rare case of potentially immune-mediated bilateral patchy paralysis may have important implications in the understanding of clinical and pathological heterogenicity of neuralgic amyotrophy.

[A case suspected Sensory Guillain-Barré syndrome subsequent to Campylobacter jejuni enteritis]

A 9-year-old girl was admitted to our hospital with severe plantar pain, 7 days after the onset of Campylobacter jejuni enteritis. On admission, extremity strength and the deep tendon reflex were normal; however, there was difficulty in walking owing to plantar pain. Motor nerve conduction test showed no abnormalities. No spinal cord protein cell dissociation. Lumbar spine-enhanced MRI showed a 4th and 5th lumbar vertebrae nerve root contrast-enhanced effect. Gabapentin was effective in minimizing her pain, eventually enabling the patient to walk. Antiganglioside antibody tests on admission showed multiple positive results. Six months after the initial onset of symptoms, she had recovered completely. She was suspected with sensory Guillain-Barré syndrome (GBS). GBS subsequent to Campylobacter jejuni enteritis has been recognized as an acute motor axonal neuropathy; hence, this report is considered to be valuable.

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.

Childhood-onset multifocal motor neuropathy with IgM antibodies to GM2 and GalNac-GD1a

BACKGROUND

Multifocal motor neuropathy (MMN) is an acquired immune-mediated form of neuropathy characterized by upper and asymmetric limb weakness without sensory loss. The mean age of onset is 40 years (range, 20-70 years), and childhood-onset MMN is extremely rare. In the present report, we discuss a case of childhood-onset MMN in a patient who tested positive for anti-GM2 and anti-GalNac-GD1a immunoglobulin M (IgM) antibodies.

CASE REPORT

A 12-year-old girl presented with progressive weakness of the upper extremities without sensory loss. Electrophysiological assessments revealed definite conduction blocks in the left median and bilateral radial nerves. She was diagnosed with MMN in accordance with the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) criteria. Serological studies revealed that she tested positive for IgM antibodies to GM2 and GalNac-GD1a. Partial improvements in both muscle weakness and electrophysiological assessments were achieved after 8 months of high-dose intravenous immunoglobulin (IVIg) treatment.

CONCLUSION

Although childhood-onset MMN is rare, most patients respond to IVIg treatment. This is the first case of childhood-onset MMN in a patient who tested positive for anti-GM2 and anti-GalNac-GD1a IgM antibodies. Although half of the adult patients with MMN test positive for anti-GM1 IgM antibodies, they were not detected in our patient. Comprehensive testing for serum anti-glycolipid antibodies in addition to GM1 may aid in the diagnosis of childhood-onset MMN.

[Guillain-Barré syndrome following cytomegalovirus infection with increased level of antibody against moesin-a case report]

A 28-year-old man noticed sensory disturbance in the distal parts of his four extremities and muscle weakness of his hands two weeks after cytomegalovirus (CMV) infection. He had splenomegaly, impairment of hepatic function and peripheral neuropathy with decreased tendon reflexes. Protein-cell dissociation was observed in the cerebrospinal fluid, and the nerve conduction study (NCS) showed the changes due to demyelination. Intravenous immunoglobulin therapy was performed for 5 days after the diagnosis of Guillain-Barré syndrome. He did not show any severe symptoms such as bulbar palsy and was discharged on day 16. Anti-GM2 and anti-GalNAc-GD1a IgM antibodies were detected and acute inflammatory demyelinating polyneuropathy following the CMV infection was confirmed. NCS showed the abnormal changes were normalized after 4 months. The levels of antibodies against moesin, which is a protein existing in trace amounts in node of Ranvier, were increased. However, the antibodies were not detected 4 months after therapy. These changes were well correlated to his clinical course.

Guillain-Barré syndrome, transverse myelitis and infectious diseases

Guillain-Barré syndrome (GBS) and transverse myelitis (TM) both represent immunologically mediated polyneuropathies of major clinical importance. Both are thought to have a genetic predisposition, but as of yet no specific genetic risk loci have been clearly defined. Both are considered autoimmune, but again the etiologies remain enigmatic. Both may be induced via molecular mimicry, particularly from infectious agents and vaccines, but clearly host factor and co-founding host responses will modulate disease susceptibility and natural history. GBS is an acute inflammatory immune-mediated polyradiculoneuropathy characterized by tingling, progressive weakness, autonomic dysfunction, and pain. Immune injury specifically takes place at the myelin sheath and related Schwann-cell components in acute inflammatory demyelinating polyneuropathy, whereas in acute motor axonal neuropathy membranes on the nerve axon (the axolemma) are the primary target for immune-related injury. Outbreaks of GBS have been reported, most frequently related to Campylobacter jejuni infection, however, other agents such as Zika Virus have been strongly associated. Patients with GBS related to infections frequently produce antibodies against human peripheral nerve gangliosides. In contrast, TM is an inflammatory disorder characterized by acute or subacute motor, sensory, and autonomic spinal cord dysfunction. There is interruption of ascending and descending neuroanatomical pathways on the transverse plane of the spinal cord similar to GBS. It has been suggested to be triggered by infectious agents and molecular mimicry. In this review, we will focus on the putative role of infectious agents as triggering factors of GBS and TM.

Ambiguous value of anti-ganglioside IgM autoantibodies in Guillain-Barré syndrome and its variants

Anti-ganglioside autoantibodies of the IgG type are detected in a half of patients with Guillain-Barré syndrome (GBS), and their detection strongly supports the diagnosis of GBS. In contrast, anti-ganglioside IgM antibodies are also often detected in GBS patients, but it remains unclear whether IgM antibodies indicate a diagnosis of GBS. We identified four GBS patients (3.3%) who tested positive for IgM antibodies but negative for IgG antibodies among 122 patients with GBS and its variants. These four patients were all adolescents or young adults (age 13-22 years), experienced preceding gastrointestinal symptoms, and had serological and/or bacterial evidence of recent Campylobacter jejuni enteritis. Serum IgG reacted strongly with the lipo-oligosaccharide (LOS) of the C. jejuni isolates from these patients' stool specimens. Thin-layer chromatography with immunostaining showed that their serum IgG reacted with resorcinol-positive portion of LOS, suggesting that these patients had IgG autoantibodies against sialic acid-containing epitopes, probably unrecognized ganglioside-like structures on the bacterial LOS. We also examined anti-ganglioside autoantibodies in 22 patients with C. jejuni enteritis without subsequent neurological disorders and detected IgM antibodies in seven (32%) patients. Our data indicate that anti-ganglioside IgM antibodies can be detected in C. jejuni enteritis without complication of GBS, and that the detection of anti-ganglioside IgM antibodies does not always support a diagnosis of GBS. IgG autoantibodies against unrecognized gangliosides might play a role in the development of disease in patients with GBS in whom only anti-ganglioside IgM antibodies are detected by routine clinical testing.

Guillain-Barré syndrome variant with facial diplegia and paresthesias associated with IgM anti-GalNAc-GD1a antibodies

We herein report the case of a 19-year-old woman with facial diplegia and paresthesias (FDP) preceded by flu-like symptoms. We diagnosed the patient with a regional variant of Guillain-Barré syndrome due to decreased tendon reflexes, albuminocytological dissociation in the cerebrospinal fluid and demyelinating features on nerve conduction studies. The patient also had IgM anti-GalNAc-GD1a antibodies, and treatment with glucocorticoids was effective for treating the facial diplegia, but not paresthesia. Therefore, facial palsy may have a different pathophysiology from paresthesia or other symptoms of FDP, which responds to glucocorticoid therapy.

Bilateral optic neuropathy with bilateral putaminal lesions: a case report

Bilateral optic neuropathy with bilateral putaminal lesions may be caused by methanol or cyanide poisoning or mitochondrial disorders including Leber hereditary optic neuropathy and Leigh syndrome. We report the case of a 34-year-old Japanese man who developed bilateral visual loss 5 days after the development of gastrointestinal symptoms. Magnetic resonance imaging of the brain on admission revealed high-intensity signal areas in the bilateral putamina on diffusion-weighted and T2-weighted images as well as a high-intensity signal area in the left middle cerebellar peduncle that had been identified 3 years previously. We diagnosed bilateral optic neuropathy with bilateral putaminal lesions caused by preceding infection-triggered demyelination. We administered methylprednisolone, but his vision did not recover.

Tolosa-hunt syndrome associated with cytomegalovirus infection

We herein present the case of a 38-year-old woman with left-sided oculomotor paralysis with ocular pain that developed after a respiratory infection. Her serum was positive for IgM against GM2 and GalNAc-GD1a gangliosides and cytomegalovirus. Thin-slice magnetic resonance imaging revealed enhanced abnormal tissue located primarily in the superolateral part of the left-sided cavernous sinus, which corticosteroids subsequently obscured with immediate resolution of the patient's ocular symptoms. These clinical features were consistent with those of Tolosa-Hunt syndrome (THS). Our findings in the present patient suggest that cytomegalovirus may provoke granuloma formation in the cavernous sinus, as reported in other various organs, thereby leading to the development of THS.

Four cases of anti-ganglioside antibody-positive neuralgic amyotrophy with good response to intravenous immunoglobulin infusion therapy

Neuralgic amyotrophy (NA), which is an idiopathic disorder in the peripheral nerves, is characterized by an acute onset of unilateral pain in the proximal limbs followed by muscular weakness and wasting. Some cases of NA are thought to be related to immune pathogenic disorders such as Guillain-Barré syndrome (GBS). We report the case of four patients with NA who were positive for anti-N-acetylgalactosaminyl GD1a (anti-GalNAc-GD1a) antibodies, had a preceding infection, and showed a good response to intravenous immunoglobulin infusion therapy. Anti-ganglioside antibodies, especially the anti-GalNAc-GD1a antibody, may be a useful marker for predicting response to immune therapy.

Antibodies to gangliosides and ganglioside complexes in Guillain-Barré syndrome and Fisher syndrome: mini-review

Antiganglioside antibodies play a pathogenic role in the pathophysiology of Guillain-Barré syndrome (GBS) and Fisher syndrome (FS). Antiganglioside antibody-mediated nerve injury is likely to result from nerve damage through complement activation or dysfunction of molecules such as voltage-gated sodium and calcium channels. Clustered epitopes of complexes of two gangliosides in the cell membrane can be targeted by serum antibodies in GBS and FS and may regulate the accessibility and avidity of antiganglioside antibodies. The glycolipid environment or the specific distribution of target gangliosides in the peripheral nervous system may also influence the pathogenic effect of antiganglioside antibodies in GBS and FS. Structural and functional analyses of glycoepitopes of ganglioside complexes in membranes will provide new vistas on antibody-antigen interaction in GBS and shed light on microdomain function mediated by carbohydrate-carbohydrate interactions, which may lead to novel treatments for GBS and FS.

Antiganglioside antibodies and their pathophysiological effects on Guillain-Barré syndrome and related disorders--a review

Guillain-Barré syndrome (GBS) is an acute immune-mediated polyradiculoneuropathy which can cause acute quadriplegia. Infection with micro-organisms, including Campylobacter jejuni (C. jejuni), Haemophilus influenzae, and Cytomegalovirus (CMV), is recognized as a main triggering event for the disease. Lipooligosaccharide (LOS) genes are responsible for the formation of human ganglioside-like LOS structures in infectious micro-organisms that can induce GBS. Molecular mimicry of LOSs on the surface of infectious agents and of ganglioside antigens on neural cells is thought to induce cross-reactive humoral and cellular immune responses. Patients with GBS develop antibodies against those gangliosides, resulting in autoimmune targeting of peripheral nerve sites, leading to neural damage. Heterogeneity of ganglioside expression in the peripheral nervous system (PNS) may underlie the differential clinical manifestation of the GBS variants. Recent studies demonstrate that some GBS sera react with ganglioside complexes consisting of two different gangliosides, such as GD1a and GD1b, or GM1 and GD1a, but not with each constituent ganglioside alone. The discovery of antiganglioside complex antibodies not only improves the detection rate of autoantibodies in GBS, but also provides a new concept in the antibody-antigen interaction through clustered carbohydrate epitopes. Although ganglioside mimicry is one of the possible etiological causes of GBS, unidentified factors may also contribute to the pathogenesis of GBS. While GBS is not considered a genetic disease, host factors, particularly human lymphocyte antigen type, appear to have a role in the pathogenesis of GBS following C. jejuni infection.

[A case of Bickerstaff brainstem encephalitis concomitant with axonal Guillain-Barre syndrome and ballism successfully treated with intravenous immunoglobulin treatment]

A 39-year-old man acutely developed diplopia, vertigo, unsteady gait, and disturbance of consciousness following an upper respiratory infection. Neurological examination showed ophthalmoplegia, facial paralysis, tetraplegia and loss of deep tendon reflexes. Babinski reflex was positive on the left and there were bilateral flexor withdrawal reflexes. He also developed ballism-like involuntary movements in all extremities, loss of proprioception predominantly on the left, and severe truncal ataxia. Anti-GQ1b IgG antibody was selectively elevated in serum, and CSF protein was elevated to 53 mg/dl with cell count of 12/mm3. Nerve conduction study showed decreased amplitude of compound motor action potentials in all extremities, and no response in facial muscles. Cranial MRI showed no abnormalities whereas EEG was severely abnormal with lack of posterior dominant rhythm and the presence of continuous diffuse theta-waves. This case presented clinical characteristics of three syndromes concurrently-Fisher syndrome, Bickerstaff brainstem encephalitis, and Guillain-Barré syndrome-that may be collectively called 'anti-GQ1b IgG antibody syndrome'. The unique feature of the present case was development of deep coma and ballism-like movements, associated with selective increase of serum anti-GQ1b IgG antibody. It is thus conceivable that anti-GQ1b IgG antibody might underlie the pathogenesis of all three conditions.

IgG anti-GalNAc-GD1a antibody inhibits the voltage-dependent calcium channel currents in PC12 pheochromocytoma cells

We investigated the effects of IgG anti-GalNAc-GD1a antibodies, produced by immunizing rabbits with GalNAc-GD1a, on the voltage-dependent calcium channel (VDCCs) currents in nerve growth factor (NGF)-differentiated PC12 pheochromocytoma cells. VDCCs currents in NGF-differentiated PC12 cells were recorded using the whole-cell patch-clamp technique. Immunized rabbit serum that had a high titer of anti-GalNAc-GD1a antibodies inhibited the VDCCs currents in the NGF-differentiated PC12 cells (36.0+/-9.6% reduction). The inhibitory effect of this serum was reversed to some degree within 3-4 min by washing with bath solution. Similarly, application of purified IgG from rabbit serum immunized with GalNAc-GD1a significantly inhibited the VDCCs currents in PC12 cells (30.6+/-2.5% reduction), and this inhibition was recovered by washing with bath solution. Furthermore, the inhibitory effect was also observed in the GalNAc-GD1a affinity column binding fraction (reduction of 31.1+/-9.85%), while the GalNAc-GD1a affinity column pass-through fraction attenuated the inhibitory effect on VDCCs currents. Normal rabbit serum and normal rabbit IgG did not affect the VDCCs currents in the PC12 cells. In an immunocytochemical study using fluorescence staining, the PC12 cells were stained using GalNAc-GD1a binding fraction. These results indicate that anti-GalNAc-GD1a antibodies inhibit the VDCCs currents in NGF-differentiated PC12 cells.

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.

Anti-ganglioside complex antibodies in Miller Fisher syndrome

BACKGROUND

Some ganglioside complexes (GSCs) are target antigens for serum antibodies in patients with Guillain-Barré syndrome (GBS). Anti-GSC antibodies may be associated with particular clinical features of GBS.

OBJECTIVE

To investigate antibodies to GSCs in the sera of patients with Miller Fisher syndrome (MFS) characterised by elevation of the IgG anti-GQ1b antibody.

RESULTS

In all, 7 of 12 (58%) consecutive patients with MFS were found to have IgG antibodies to GSCs containing GQ1b, of whom 5 had IgG antibodies to GQ1b-GM1 complex (GQ1b/GM1) and 2 had antibodies to GQ1b/GD1a; 4 of 5 patients without sensory symptoms had anti-GQ1b/GM1 antibodies.

CONCLUSIONS

At least three different specificities in MFS-associated antibodies, GQ1b-specific, anti-GQ1b/GM1-positive and anti-GQ1b/GD1a-positive, were observed. In patients with MFS not only GQ1b itself but also clustered epitopes of GSCs, including GQ1b, may be considered to be prime target antigens for serum antibodies. A tendency to escape sensory disturbances is shown by anti-GQ1b/GM1-positive MFS.

Spectrum of neurological diseases associated with antibodies to minor gangliosides GM1b and GalNAc-GD1a

The authors reported the neurological disease spectrum associated with autoantibodies against minor gangliosides GM1b and GalNAc-GD1a. IgG and IgM antibody reactivity against gangliosides GM1, GM2, GM1b, GD1a, GalNAc-GD1a and GQ1b was investigated in sera from 7000 consecutive patients who had various neurological conditions. The clinical diagnoses for 456 anti-GM1b-positive patients were Guillain-Barré syndrome (GBS, 71%), atypical GBS with preserved deep tendon reflexes (12%), Fisher syndrome (10%), Bickerstaff's brainstem encephalitis (2%), ataxic GBS (2%) and acute ophthalmoparesis (1%). For 193 anti-GalNAc-GD1a-positive patients, the diagnoses were GBS (70%), atypical GBS (16%), Fisher syndrome (10%) and Bickerstaff's brainstem encephalitis (3%). Of the patients with GBS or atypical GBS, 28% of 381 anti-GM1b-positive and 31% of 166 anti-GalNAc-GD1a-positive patients had neither anti-GM1 nor anti-GD1a antibodies. Of those patients with Fisher syndrome, Bickerstaff's brainstem encephalitis, ataxic GBS or acute ophthalmoparesis, 33% of 67 anti-GM1b-positive, and 52% of 25 anti-GalNAc-GD1a-positive patients had no anti-GQ1b antibodies. Autoantibodies against GM1b and GalNAc-GD1a are associated with GBS, Fisher syndrome and related conditions. These antibodies should provide useful serological markers for identifying patients who have atypical GBS with preserved deep tendon reflexes, ataxic GBS, Bickerstaff's brainstem encephalitis or acute ophthalmoparesis, especially for those who have no antibodies to GM1, GD1a or GQ1b. A method to prepare GM1b was developed.

IgM antibodies to N-acetylgalactosaminyl GD1a in benign monomelic amyotrophy of the lower limb

A male Caucasian patient is presented with a greater than 10-year history of painless weakness of the right leg, stable over the last 7 years. His examination demonstrated severe wasting and moderate weakness of his right calf muscle. Electrodiagnostic study revealed acute denervation of the right calf and chronic partial denervation of multiple right leg muscles. MRI demonstrated atrophy and fatty infiltration of the right calf muscles. Based on previous clinical, electrophysiologic, and radiologic descriptions of this disorder, a diagnosis was made of benign monomelic amyotrophy of the lower limb. Serologic examination for anti-glycoconjugate antibodies revealed high titers of IgM antibodies with selective binding to the disialoganglioside N-acetylgalactosaminyl GD1a (GalNAcGD1a). Testing for antibodies to GalNAcGD1a should be considered in patients with this phenotype. Their presence could suggest a role for immunomodulatory therapy.

Harmful effects of anti-GalNAc-GD1a antibodies and TNF-alpha on rat dorsal root ganglia

The clinical characteristics of five (22%) of 23 patients with Guillain-Barré syndrome (GBS), whose serum contained immunoglobulin G (IgG) antibodies to the ganglioside N-acetylgalactosaminyl GD1a (GalNAc-GD1a), included pure motor weakness of the axonal type. These patients had a relatively good prognosis, but displayed higher serum tumor necrosis factor-alpha (TNF-alpha) titers than the other GBS patients. We examined the effect of serum from these patients with IgG anti-GalNAc-GD1a antibodies on neurites from cultured rat dorsal root ganglia (DRG) and found it to damage the myelin in well-elongated DRG neurites and monolayer cultures of Schwann cells and neurons. In the regeneration model, serum from these patients delayed neurite extension and inhibited Schwann cell proliferation. Neurons in cultured monolayers showed vacuolation and decreased rapidly in number. Schwann cells were also vacuolated and readily detached from the substratum. The effects of IgG anti-GalNAc-GD1a antibodies purified from one of the patients, rabbit serum after immunization with GalNAc-GD1a, and recombinant TNF-alpha were also examined. IgG anti-GalNAc-GD1a antibodies mainly inhibited the regeneration and preservation of neurons, while TNF-alpha mainly induced morphological changes in well-proliferated Schwann cells and myelin.

Increased circulating T cell reactivity to GM1 ganglioside in patients with Guillain–Barré syndrome

This study was performed to determine whether increased ganglioside-specific T cell reactivity can be detected in the peripheral blood of patients with Guillain-Barre syndrome (GBS) and chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). T cell responsiveness to the gangliosides GM1, GM3, GD1a, GD1b, GD3, GT1b, GQ1b and sulphatide was assessed in peripheral blood mononuclear cells from untreated GBS patients (57), CIDP patients (43), patients with other peripheral neuropathies (55) and healthy control subjects (74) in a standard 6-day proliferation assay. Increased T cell reactivity to GM1 occurred in GBS patients compared to healthy controls and patients with other neuropathies. There was increased reactivity to GM3 in GBS patients compared to patients with other neuropathies but not compared to healthy controls. The frequencies of increased T cell reactivity to GM1 and GM3 in CIDP patients were intermediate between those of GBS patients and controls. We suggest that T cell reactivity to gangliosides might play a contributory role in the pathogenesis of GBS and perhaps CIDP.

Antiglycolipid antibodies in Guillain-Barré syndrome and related diseases: Review of clinical features and antibody specificities

Guillain-Barré syndrome (GBS) is an acute inflammatory polyradiculoneuropathy that usually develops following a respiratory or intestinal infection. Although the pathogenic mechanisms of GBS have not been fully established, both humoral and cell-mediated immune factors have been shown to contribute to the disease process. Several antiglycosphingolipid (anti-GSL) antibodies have been found in the sera of patients with GBS or related diseases. Measurements of these antibody titers are very important in the diagnosis of GBS and in evaluating the effectiveness of treatments in clinical trials. The most common treatment strategies for these disorders involve plasmapheresis and the use of steroids for reducing anti-GSL antibody titers to ameliorate patients' clinical symptoms. Administration of intravenous immunoglobulin may also be beneficial in the treatment of neuropathies by suppressing the immune-mediated processes that are directed against antigenic targets in myelin and axons. In certain demyelinating neuropathies, the destruction or malfunctioning of the blood-nerve barrier, which results in the leakage of circulating antibodies into the peripheral nerve parenchyma, has been considered to be an initial step in development of the disease process. In addition, anti-GSL antibodies, such as anti-GM1, may cause nerve dysfunction and injury by interfering with the ion channel function at the nodes of Ranvier, where carbohydrate epitopes of glycoconjugates are located. These malfunctions thus contribute to the pathogenic mechanisms of certain demyelinating neuropathies.

Neurophysiological and immunohistochemical studies on Guillain-Barré syndrome with IgG anti-GalNAc-GD1a antibodies—effects on neuromuscular transmission

We investigated the epitopes and functional role of IgG anti-GalNAc-GD1a antibodies appearing in serum from a patient with Guillain-Barre syndrome (GBS) and IgG anti-GalNAc-GD1a antibody that was produced by immunization of a rabbit with GalNAc-GD1a. Both sera blocked neuromuscular transmission in muscle-spinal cord co-culture cells. The acetylcholine-induced potential did not reduce by adding sera, suggesting that the blockade is presynaptic. The effect was complement-independent and purified IgG from serum of the patient or the rabbit had the same effects. The epitope with both anti-GalNAc-GD1a antibodies was observed in the soma of large neurons in the anterior horns of the adult rat spinal cord and their motor axons of rat ventral roots. Both anti-GalNAc GD1a antibodies reacted strongly with the motor nerve terminals in rats. The anti-GalNAc-GD1a antibodies may block neuromuscular transmission by attacking on presynaptic motor axon, probably affecting the ion channels in the presynaptic motor axon.

Severe sensory ataxia and demyelinating polyneuropathy with IgM anti-GM2 and GalNAc-GD1A antibodies

Several polyneuropathy syndromes have been described with polyclonal serum immunoglobulin G (IgG) or immunoglobulin M (IgM) binding to gangliosides GM2 and GalNAc-GD1a that contain the terminal trisaccharide moiety GalNAc(beta1-4)Gal(alpha2-3)NeuAc. We describe the clinical and electrodiagnostic features in two patients with serum IgM monoclonal anti-GM2 and anti-GalNAc-GD1a antibodies. These patients had slowly progressive, panmodal sensory loss with severe sensory ataxia. Electrodiagnostic testing showed demyelinating features. Prominent improvement in gait ataxia occurred after treatment with human immune globulin but not after other immunomodulating therapies. Enzyme-linked immunoabsorbent assay and thin-layer chromatography demonstrate that the patient's serum monoclonal IgM bound to gangliosides GM2 and GalNac-GD1a but not to gangliosides without the GalNAc(beta1-4)Gal(alpha2-3)NeuAc moiety. This neuropathy differs from previously reported neuropathy syndromes associated with polyclonal GM2 and GalNAc-GD1a antibodies and from other chronic demyelinating polyneuropathies. We conclude that a distinct syndrome of chronic demyelinating neuropathy with sensory ataxia, unresponsive to corticosteroids, is associated with monoclonal IgM binding to gangliosides with a terminal GalNAc(beta1-4)Gal(alpha2-3)NeuAc trisaccharide moiety. Diagnosis of this syndrome is important to direct appropriate treatment.

The relationship of Campylobacter jejuni infection and the development of Guillain-Barré syndrome

Campylobacter jejuni is recognized as the most common infectious agent associated with the development of Guillain-Barré syndrome. Available information on the complete genome sequence of C. jejuni NCTC 11168 has helped researchers to identify polysaccharide capsules as well as genetic mechanisms in the synthesis of ganglioside-like cell surface molecules in this bacteria. Toxins may contribute to the host's inflammatory response seen in Guillain-Barré syndrome.

Progress in Guillain-Barré syndrome

This editorial review summarizes and critically analyses reports published in the preceding 18 months on the pathogenesis of Guillain-Barré syndrome, with particular emphasis on the role of ganglioside antibodies, antecedent infections, and the concept of molecular mimicry. It concludes with an appraisal of currently available and proposed therapies.