Multiple sclerosis is associated with enhanced B cell responses to the ganglioside GD1a

The occurrence and role of autoantibodies to gangliosides and other lipid-containing components of the central nervous system in Multiple Sclerosis (MS) are unsettled. Using sensitive ELISAs, we measured IgG and IgM antibody titers and absorbances to the three major gangliosides GD1a, GD1b and GM1, and to sulfatides, cardiolipin and myelin proteins in paired serum and cerebrospinal fluid (CSF) from patients with untreated MS, optic neuritis (ON), acute aseptic meningo-encephalitis (AM) and other neurological diseases (OND). Twenty-three per cent of 30 MS (P<0.04) and 18% of 32 ON patients (P<0.05) presented elevated IgG antibody titers to GD1a in serum compared to 9% of patients with OND. Six (40%) of the patients with malignant MS had elevated serum IgG antibody titers to GD1a compared to one (6%) of the patients with benign MS (P<0.04). In CSF, elevated IgG antibody titers to GD1a were measured in 13% of MS and 20% of ON patients compared to 4% of patients with OND (P<0. 03 and P<0.02, respectively). The augmented IgG response to GD1a in serum also separated MS from Guillain-Barré syndrome. Compared to OND increased IgM absorbances to sulfatides and cardiolipin were observed in CSF of patients with MS, but also in AM. Elevated IgG antibody titers to myelin proteins were found more often in MS patients' serum and MS, ON and AM patients' CSF compared to OND. The data implicate that among the multitude of enhanced B-cell responses occurring in MS and ON, that directed to GD1a is common and more discriminative, and should be evaluated in future MS treatment studies.     

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.     

Expression of gangliosides on glial and neuronal cells in normal and pathological adult human brain

Few studies have assessed the glycolipid phenotype of glial cells in the human central nervous system (CNS) in situ. We investigated by immunohistochemistry the expression and cellular distribution of a panel of gangliosides (GM1, GM2, acetyl-GM3, GD1a, GD1b, GD2, GD3, GT1b, GQ1b and the A2B5 antibody) in adult, human normal and pathological brain, namely multiple sclerosis (MS) and other neurological diseases (OND). In normal conditions, we found diffuse expression in the white matter of most gangliosides tested, with the exception of acetyl-GM3, GT1b and GQ1b. By double immunofluorescence with phenotypic markers, GM1 and GD1b were preferentially expressed on GFAP+ astrocytes, GD1a on NG2+ oligodendrocyte precursors, A2B5 immunostained both populations, while GD2 was selectively present on mature oligodendrocytes. In the gray matter, only GM1, GD2 and A2B5 were present on neuronal cells. Interestingly, those gangliosides present on astrocytes in normal conditions were preferentially expressed on NG2+ cells in chronic MS lesions and in OND. Selective expression of GT1b upon astrocytes and NG2+ cells was instead observed in MS lesions, but not in OND. The definition of the glycolipid phenotype of CNS glial cells may be useful to identify distinct biological glial subsets and provide insights on the potential autoantigenic role of gangliosides in CNS autoimmune diseases.     

Antibodies to GD1alpha and to GQ1beta in Guillain-Barré syndrome and the related disorders.

Certain species of anti-ganglioside antibodies are associated with specific clinical features in various neurologic diseases. Serum autoantibodies to these minor gangliosides were investigated in a number of neurological diseases in order to examine the biological functions of GD1alpha and GQ1beta. Eleven patients with Guillain-Barré syndrome had remarkably high IgG anti-GD1alpha antibody titers, but no GD1alpha was detected in human peripheral nerve. An absorption study showed that IgG anti-GD1alpha antibodies from eight of the 11 patients were significantly absorbed by GD1a and GM1b, indicative that the IgG anti-GD1alpha antibodies cross-react with GD1a and GM1b. Both GD1a and GM1b have been reported to be target molecules for serum antibodies in certain patients with Guillain-Barré syndrome. GD1alpha may induce the production of IgG anti-GD1alpha antibody which cross-reacts with GD1a or GM1b, and subsequently functions in the development of Guillain-Barré syndrome. The IgGs from six patients with Fisher's syndrome who had the anti-GQ1beta antibody had anti-GQ1b activity as well. All the patients had external ophthalmoplegia, but no GQ1beta was detected in the human oculomotor nerve, further evidence that GQ1b, not GQ1beta, is the molecule targeted by the autoantibody in Fisher's syndrome.     

Microheterogeneity of anti-myelin-associated glycoprotein antibodies

Antibodies to the myelin-associated glycoprotein (MAG) are implicated in the pathogenesis of an acquired demyelinating polyneuropathy. We studied IgM affinity to MAG in 18 patients with anti-MAG antibodies. Binding of sera was tested for anti-MAG immunoreactivity in central nervous system (CNS) by ELISA and in CNS and peripheral nervous system (PNS) by Western blot analysis. Furthermore, immunohistochemical characterization of IgM binding on sural nerve tissue was investigated using the indirect peroxidase method. Western blot analysis revealed that all sera detected MAG in central myelin, but only eight in peripheral myelin. Anti-MAG-IgM-ELISA-titers correlated significantly (p<0.0001) with PNS-Western blot results. By indirect immunoperoxidase immunohistochemistry, 12 sera stained myelin sheaths, while 6 sera showed no staining. These results demonstrate considerable variations in antibody binding strength to MAG between PNS myelin and CNS myelin. The relevance of these differences for the pathogenesis of the neuropathy and clinical impairment remains to be demonstrated.     

Antiganglioside antibodies in Guillain-Barré syndrome after a recent cytomegalovirus infection

OBJECTIVE: To study the association between anti-ganglioside antibody responses and Guillan-Barré syndrome (GBS) after a recent cytomegalovirus (CMV) infection. METHODS: Enzyme linked immunosorbant assay (ELISA) was undertaken on serum samples from 14 patients with GBS with recent cytomegalovirus (CMV) infection (CMV+GBS) and 12 without (CMV-GBS), 17 patients with other neurological diseases (OND), 11 patients with a recent CMV infection but without neurological involvement, 11 patients with recent Epstein-Barr virus (EBV) infection but without neurological involvement, and 20 normal control (NC) subjects. RESULTS: IgM antibodies were found at 1:100 serum dilution to gangliosides GM2 (six of 14 patients), GM1 (four of 14), GD1a (three of 14) and GD1b (two of 14) in the serum samples of the CMV+GBS patients, but not in those of any of the CMV-GBS patients. IgM antibodies were also found to gangliosides GM1, GD1a, and GD1b in one of 11 OND patients, to ganglioside GM1 in one of 11 non- neurological CMV patients, and to ganglioside GD1b in one of 20 NC subjects. Some patients with EBV infection had IgM antibodies to gangliosides GM1 (five of 11), GM2 (three of 11), and GD1a (two of 11). However, the antibodies to ganglioside GM2 had a low titre, none being positive at 1:200 dilution, whereas five of the CMV+GBS serum samples remained positive at this dilution. CONCLUSION: Antibodies to ganglioside GM2 are often associated with GBS after CMV infection, but their relevance is not known. It is unlikely that CMV infection and anti-ganglioside GM2 antibodies are solely responsible and an additional factor is required to elicit GBS.     

Monoclonal IgM in a patient with paraproteinemic polyneuropathy binds to gangliosides containing disialosyl groups

Monoclonal IgM kappa from a patient with polyneuropathy associated with paraproteinemia was found to bind to several polysialogangliosides. Binding of IgM to gangliosides was shown by enzyme-linked immunosorbent assay (ELISA) and by overlaying thin-layer chromatograms of human brain and peripheral nerve gangliosides with the patient's serum followed by radioiodinated goat antihuman IgM. The latter technique showed that the IgM paraprotein reacted with a number of gangliosides. In an ELISA the IgM paraprotein reacted strongly with GD2, GD3, GD1b, and GT1b, but not with GM1, GM3, and GD1a. Thus, the epitope for the patient's IgM paraprotein appears to involve the disialosyl configurations.     

Intrathecal immune response in patients with neuroborreliosis: specificity of antibodies for neuronal proteins

Cerebrospinal fluid (CSF) and serum samples of 47 patients with serologically proven neuroborreliosis were examined by Western blotting for antibodies to a crude extract of human cortex (CNS) comprising a multitude (> 40) of protein bands. Intrathecal synthesis of total immunoglobulins was determined by the Reiber formula and of autoantibodies to CNS proteins by enzyme-linked immunoassay (ELISA) and by Western blotting. Employing ELISA, intrathecal synthesis of autoantibodies (IgG, IgM and/or IgA) was demonstrated in 40 of 47 patients with neuroborreliosis (85%), in 5 of 40 with multiple sclerosis (12%), and in 22 of 40 with viral meningoencephalitis (55%). Of 40, 35 and 15 patients with neuroborreliosis and an intrathecal synthesis of total IgG, IgM or IgA, 20 revealed an intrathecal production of IgG antibodies (50%), 24 of IgM antibodies (68%) and 6 of IgA autoantibodies (40%) in the CSF. The specificity of autoantibodies differed greatly between most patients. Of 24 different CNS proteins which elicited an immune response in various patients, identities could be determined only for the myelin basic protein (5 of 40) and for the three neurofilament proteins (NF-68, NF-150, NF-200) (13 of 40 patients). In this limited number of patients no significant correlation between individual clinical symptoms and certain autoantibodies could be detected. The higher frequency of intrathecally produced autoantibodies in patients with neuroborreliosis is assumed to result from mitogenic rather than specific activation of autoreactive B-cell clones byBorrelia burgdorferi. The pathogenic relevance of these autoantibodies remains to be determined.     

Cellular hypersensitivity to gangliosides and myelin basic protein in multiple sclerosis

Peripheral blood lymphocytes from patients with multiple sclerosis (MS), other neurological diseases and healthy controls were investigated for the presence of cell-mediated hypersensitivity to brain gangliosides and myelin basic protein using an active E-rosette assay. Sensitivity to myelin basic protein and gangliosides was found in MS patients in acute relapse and with progressive disease, whereas no sensitivity was found in MS patients in remission. Patients with other neurological diseases showed no response to gangliosides, but sensitization to myelin basic protein was found in a patient with leucoencephalopathy and in 4 of 6 stroke patients. Healthy controls did not respond to either antigen. In MS patients a positive correlation was seen between lymphocyte responses to myelin basic protein and to gangliosides. The data suggest that in comparison to gangliosides, myelin basic protein is a weaker stimulator of active rosette-forming cells. Moreover, cellular hypersensitivity to myelin basic protein is not MS-specific and may be present as a consequence of brain damage. However, cellular hypersensitivity to gangliosides appears to be more specific to MS and may be important in the pathogenesis of the disease.     

Antibodies to the ganglioside GD1b in a patient with motor neuron disease and thyroid adenoma

Patients with motor neuron disease with thyroid disorders have been described, although the relationship between the two conditions is unclear. We treated a patient with amyotrophic lateral sclerosis who also had a follicular adenoma of the thyroid gland. Because thyroid gland plasma membranes contain high concentrations of complex gangliosides, such as GD1b, and some patients with motor neuron disease have IgM antibodies to GD1b, we decided to assay serum from this patient for the presence of antiganglioside antibodies. IgM antibodies to GD1b were detectable at serum dilutions of 1:500 and 1:1000 by enzyme-linked immunosorbent assay. While these titers are less than those usually described in patients with plasma cell dyscrasia, they are well in excess of normal values. Antibody to GM1 was also detectable at a lower (1:100) dilution. We do not know the importance of the anti-GD1b antibodies in this patient, but it is possible that antibodies to GD1b are involved in this and other cases of motor neuron disease associated with thyroid disease.     

Characterization of the neurological diseases associated with <Emphasis Type="Italic">Mycoplasma pneumoniae</Emphasis> infection and anti-glycolipid antibodies

Mycoplasma pneumoniae infection often causes various neurological complications of both the central nervous system (CNS) and the peripheral nervous system. We retrospectively investigated the IgM and IgG antibodies to nine glycolipids [GM1, GM2, GM3, GD1a, GD1b, GD3, GT1b, GQ1b, and Gal-C (galactocerebroside)] and clinical features in neurological diseases associated with M. pneumoniae infection diagnosed in multiple hospitals throughout Japan between September 2010 and March 2012. Of the 46 patients with neurological diseases associated with M. pneumoniae infection, 27 were diagnosed with Guillain–Barré syndrome (GBS), 2 with Fisher syndrome (FS), 16 with CNS diseases, and 1 with both GBS and CNS disease. Anti-Gal-C IgM and IgG antibodies were most frequently detected (23/46, 50%). Patients with CNS diseases were younger than patients with GBS or FS, and IgM antibodies to Gal-C were more frequently detected in the patients with CNS diseases (41%) than in those with GBS or FS (13%). Of the nine patients who were positive for anti-Gal-C IgM antibody but lacked IgG antibody, we found the class-switch of anti-Gal-C antibody from IgM to IgG in two patients. The IgG antibodies appeared during their recovery phase, and the IgG belonged to the IgG1 subclass. Anti-Gal-C antibodies are closely associated with neurological diseases after M. pneumoniae infection. Particularly, anti-Gal-C IgM antibody is more frequently detected in younger patients affected with CNS involvement. The class-switch from IgM to IgG sometimes occurs in anti-Gal-C antibodies.     

Clinical presentation and outcome of Guillain-Barré and related syndromes in relation to anti-ganglioside antibodies.

We correlated the clinical features of 78 patients with Guillain-Barré syndrome (GBS) or related variants, with the presence of serum antibodies to the gangliosides GM1, GM2, GD1a, GD1b and GQ1b in order to determine whether these antibodies may influence the clinical presentation or outcome of GBS. Sixty-three patients had typical GBS (81%), nine a pure motor form (11%), three a paraparetic form (4%), and three had Miller Fisher syndrome (MFS). IgG or IgM (or both) anti-ganglioside antibodies were found by ELISA in 37% of patients, including 36% with typical, 33% with pure motor and 100% with MFS. Beside the constant occurrence of anti-GQ1b antibodies in patients with MFS (P<0.00001), the other clinical forms were not associated with a specific anti-ganglioside reactivity. Anti-GM1 and anti-GD1a antibodies tended to be associated with a worse disability at 6 month than other or no reactivity and, similarly to anti-GM2 antibodies, with a more frequent respiratory impairment. Anti-GM2 and anti-GD1b antibodies were always associated with typical GBS and, in all but one patient, with a complete recovery; still they were found in only 13 and 3%, respectively, of the patients with this presentation. Anti-GQ1b antibodies, though always associated with ophthalmoplegia and ataxia in both MFS and GBS, were found in only 36 and 26%, respectively, of patients with these symptoms. Even if different anti-ganglioside antibodies tend to be associated with some clinical features possibly suggesting that they may influence the clinical presentation or outcome, with the exception of anti-GQ1b antibodies for ophthalmoplegia and ataxia, they do not permit to predict the clinical presentation or outcome in individual patients.     

Antibody to glycolipid in a patient with IgM paraproteinemia and polyradiculoneuropathy

Serum from a patient with IgM paraproteinemia and polyradiculoneuropathy, diagnosed as malignant lymphoma reacted specifically with a lipid component in a crude ganglioside fraction isolated from human peripheral nerve, but did not react with myelin proteins including myelin-associated glycoprotein (MAG). The reactive glycolipid migrated between GM1 and GD1a gangliosides on TLC, and there was no distinct band corresponding to this glycolipid on examination with resorcinol reagent. Antibody to glycolipid in this case may play a role in the pathogenesis of neuropathy.     

Ganglioside GD3 of cerebral neurons and Purkinje cells in aged human brains

Immunocytochemical staining for ganglioside GD3 (II^3α (NeuAcα2–8NeuAc)-LacCer, GD3) in neuronal cells of the cerebral cortices (cerebral neurons), and cerebellar dentate nucleus (dentate neurons) and Purkinje cells, in human autopsy cases of progressive supranuclear palsy, senile dementia of the Alzheimer type, Pick's disease, amyotrophic lateral sclerosis and olivopontocerebellar atrophy (OPCA) was undertaken using mouse IgM anti-GD3 monoclonal antibody. Cerebral neurons and dentate neurons were constantly GD3-immunoreactive and immunoreactivity was observed in the cytoplasm. The peroxidase reaction product for GD3 (RP) in cerebral and dentate neurons was granular in appearance. It appeared that RP was associated with lipofuscin granules. However, immunoreactivity of Purkinje cells varied among cases, and the RP was slightly granular even when they were positive. This study suggests that lipofuscin granules contributed to the neuronal immunoreactivity of GD3 in aged human brains.     

Ataxic neuropathy associated with disialosylated antibodies: description of new clinical and biochemical forms

INTRODUCTION: Polyneuropathies associated with IgM monoclonal gammopathy were recently recognized. Antibodies can react with glycoproteins such as myelin associated glycoprotein (MAG), or gangliosides containing one sialosyl epitope such as GM1 or several sialosyl epitopes (polysialyted gangliosides) including GD2, GD3, GT1b, GT1a, GQ1b. METHODS: We report on three patients presenting oculomotor dysfunction, chronic sensitive ataxic polyneuropathy, high sedimentation rate, IgM monoclonal paraprotein of unknown signification and antidisialosyl IgM antibodies and for two of them cold agglutinins. Such features have been previously described under the acronym "CANOMAD" (chronic ataxic neuropathy with ophthalmoplegia, M protein, agglutination and disialosyl antibodies). RESULTS: One of the patients presents extramembranous glomerulopathy and severe motor disability associated with this syndrome. The pathophysiology of the glomerulopathy seems to be linked with the polyneuropathy. Patients were treated either by intravenous immunoglobulin, corticosteroids or cyclophosphamid. Response to treatment differs in the three cases and there is currently no consensus. CONCLUSION: Our study demonstrates that spectrum of polyneuropathy associated with monoclonal polyneuropathy may be larger than originally described.     

Demonstration of ganglioside GD3 in human reactive astrocytes

Astrocytes are the cells that actively participate in the process of lesion repair in the central nervous system (CNS), and reactive astrocytosis of varying degrees becomes apparent with time in any pathological condition occurring in the normally developed postnatal CNS. Ganglioside GD3 (II3a(NeuAca2-8NeuAc)-LacCer, GD3) in reactive astrocytes from autopsied patients with Creutzfeldt-Jakob disease (CJD) and old cerebral infarction was investigated immunocytochemically, using mouse IgM anti-GD3 monoclonal antibody (DSG-1). Reactive astrocytes in CJD and cerebral infarction demonstrated GD3-immunoreactivity within the cytoplasm. Normal astrocytes were negative. The present data raise the possibility that GD3 in reactive astrocytes has biological implications for the properties of the cells, such as cellular motility.     

Increased circulating T cell reactivity to GM3 and GQ1b gangliosides in primary progressive multiple sclerosis.

We have previously shown that patients with primary progressive multiple sclerosis (MS) have significantly elevated plasma levels of antibody to GM3 ganglioside compared to patients with relapsing-remitting MS, healthy subjects and patients with other neurological diseases. Anti-GM3 antibody levels were elevated also in patients with secondary progressive MS but to a lesser extent than in primary progressive MS. As gangliosides are particularly enriched in the axonal membrane, these findings suggested that antiganglioside immune responses might contribute to the axonal damage in progressive forms of MS. The present study was performed to determine whether peripheral blood T cell responses to GM3 are also increased in progressive MS. Blood was collected from 98 untreated patients with MS (40 with relapsing-remitting, 27 with secondary progressive and 31 with primary progressive MS), 50 healthy subjects and 24 patients with other disorders of the CNS, and reactivity to GM1, GM3, GD1a, GD1b, GD3, GT1b, GQ1b and sulphatide was assessed by 6-day T cell proliferation assays. Increased T cell reactivity to GM3 and GQ1b occurred significantly more often in patients with primary progressive MS than in healthy subjects and patients with other CNS diseases. These findings suggest that ganglioside-specific T cells may contribute to the axonal damage in primary progressive MS.     

Serum antibodies to gangliosides in Guillain-Barré syndrome

To determine whether antibodies to acidic glycolipids of nervous tissue are present in patients with Guillain-Barré syndrome (GBS), sera from patients with GBS and appropriate control subjects were tested by a thin-layer chromatogram overlay technique. Chromatograms on which the whole ganglioside fractions from peripheral nerve and brain had been separated were overlaid with appropriate dilutions of the patients' sera (1:100 or greater), and antibody binding was revealed with a radiolabeled or peroxidase-labeled second antibody. Antibodies to ganglioside antigens were detected in 5 of 26 patients with GBS. IgG antibodies in 1 patient reacted strongly with LM1 (sialosyl paragloboside), the major ganglioside of human peripheral nervous system myelin, and its hexaose analog (sialosyl lactosaminyl paragloboside), a minor ganglioside of human peripheral nervous system myelin. The antibody titer in this patient fell 8-fold over 6 weeks coincident with clinical improvement. IgG from 2 other patients with GBS reacted with GD1b ganglioside, and the antibody titers in these patients also decreased substantially with clinical improvement. IgM antibodies in the sera from 2 other patients reacted with GD1a and GT1b gangliosides, which have a shared terminal carbohydrate sequence. Antibodies to gangliosides were not detected in the sera from 19 patients with other neurological diseases or from 10 normal subjects, and the frequency with which antiganglioside antibodies occurred in the patients with GBS was significantly greater than that in the combined control subjects (p less than 0.01). The results demonstrate relatively high levels of antibodies to gangliosides in some GBS patients.     

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

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

Temporal profile of anti-ganglioside antibodies and their relation to clinical parameters and treatment in Guillain-Barré syndrome

Elevated anti-ganglioside antibody levels mainly of anti-GM1 and anti-GD1a specificities have been reported in THE serum of patients with Guillain–Barré syndrome (GBS). The relevance of anti-ganglioside antibodies other than anti-GM1 and anti-GD1a IgG antibodies and the temporal profile of anti-ganglioside antibodies in GBS is less clear. We studied serum antibodies to GM1, GD1a, GD1b, GQ1b, sulfatide and cardiolipin of the IgM, IgG and IgA classes over the course of GBS in patients who were untreated or treated with highdose intravenous immunoglobulin (IvIg). Antibodies to GD1b, GQ1b, sulfatide and cardiolipin were not detected in the sera of the GBS patients examined in this study. Anti-GM1 IgG titers peaked around 40 days and anti-GD1a IgM around 90 days after GBS onset. Titers of anti-GM1 IgG antibodies decreased following IvIg treatment. Patients with antibody peaks, defined as fivefold or higher increase in antibody titer compared to the lowest antibody titer over the course of GBS, had higher disability scores during the first two weeks of GBS and a worse clinical outcome (anti-GM1 IgG and anti-GD1a IgM antibody peaks) and axonal damage (anti-GD1a IgM antibody peaks), compared to patients without peak antibody titers. Anti-GM1 IgG and anti-GD1a IgM antibodies are thus strongly associated with more severe- and predominantly axonal cases of GBS. The appearance of anti-GM1 IgG and anti-GD1a antibody peaks in the serum after the termination of the acute phase of GBS suggests that these antibodies are produced secondary to nerve damage in GBS. The data does not exclude the possibility that secondarily secreted anti-GM1 IgG and anti-GD1a IgM antibodies may themselves be biologically active and play a role in disease propagation and/or recovery from disease in some patients with GBS.