Patterns of serum IgM antibodies to GM1 and GD1a gangliosides in amyotrophic lateral sclerosis

Reactivity of neuroborreliosis patients (Lyme disease) to cardiolipin and gangliosides

A subset of patients (50%) with neuroborreliosis (Lyme disease) showed IgG reactivity to cardiolipin in solid phase ELISA. In addition, a subset of patients with neuroborreliosis (29%) and syphilis (59%) had IgM reactivity to gangliosides with a Gal(beta 1-3) GalNac terminal sequence (GM1, GD1b, and asialo GM1). Anti-ganglioside IgM antibodies were significantly more frequent in these two groups of patients compared to patients with cutaneous and articular Lyme disease, primary antiphospholipid syndrome, systemic lupus erythematosus and normal controls. Correlative evidence and adsorption experiments indicated that antibodies to cardiolipin had separate specificities from those directed against the gangliosides. IgM antibodies to Gal(beta 1-3) GalNac gangliosides appeared to have similar specificities since these were positively correlated and inhibitable by cross adsorption assays. Given the clinical associations of patients with neuroborreliosis and syphilis with IgM reactivity to gangliosides sharing the Gal(beta 1-3) GalNac terminus, we suggest that these antibodies could represent a response to injury in neurological disease or a cross reactive event caused by spirochetes.

Amyotrophic lateral sclerosis in a patient with systemic lupus erythematosus

We report the case of a 48-year-old woman diagnosed as having systemic lupus erythematosus who developed a neurological disorder that finally resulted in amyotrophic lateral sclerosis. Although neurological disturbances caused by systemic lupus erythematosus are protean, there are no reported cases of amyotrophic lateral sclerosis associating with lupus disease. This association and the suspected autoimmune mechanism of pathogenesis in amyotrophic lateral sclerosis suggest that this might not be a simple coincidence but perhaps a causal relationship.

Antiglycolipid antibodies, immunoglobulins and paraproteins in motor neuron disease: a population based case-control study

The role of humoral autoimmune factors in the pathogenesis of motor neuron disease (MND) is currently under considerable scrutiny. In particular, there have been many reports of abnormal serum immunoglobulin patterns and elevated titres of anti-ganglioside antibodies in patients with MND. However, many of these studies may be biased by the selection criteria for patients and controls. In order to carefully address this issue we obtained 82 blood samples from consecutive MND patients identified through a national MND register in combination with 82 community controls matched for age, sex and geographical area. We used these samples to determine the frequency of monoclonal immunoglobulins (mIgs) and measure the levels of serum immunoglobulins and anti-GM1 ganglioside antibodies in sporadic cases of MND in comparison with normal controls. Serum mIgs detected using high resolution and immunofixation agarose electrophoresis were present in 1.2% of MND patients and 2.4% of controls. Using a highly sensitive isoelectric focusing and immunoblotting method, monoclonal or oligoclonal immunoglobulins were found in 28% of MND patients and 27% of controls. Anti-GM1 antibodies were present in 26% of MND patients and 18% of controls (odds ratio = 1.5, 95%, CI 0.7-3.6) with no significant differences in titres between the 2 groups. Mean immunoglobulin G, A and M levels were equal in 2 groups. Thus, although alterations in these parameters were identified, we were unable to demonstrate any significant difference between MND patients and controls. We conclude that the majority of sporadic cases of MND are unlikely to have an autoimmune basis as judged by the lack of abnormalities in these parameters.

Experimental immune-mediated motor neuron diseases: models for human ALS

Amyotrophic lateral sclerosis is an idiopathic, ultimately fatal disease, clinically manifest as progressive weakness and spasticity, associated with the loss of motoneurons. Circumstantial evidence supports a role for autoimmune processes in the progression of this human disorder. Two immune-mediated animal models have been developed in our laboratory for motor neuron loss. Experimental autoimmune motor neuron disease is a lower motor syndrome induced in guinea pigs by the repeated injection of a purified bovine spinal motor neuron antigen. Affected animals demonstrate extremity weakness, associated with electromyographic and morphologic evidence of denervation, a loss of spinal cord motor neurons, high antibody titers against motor neurons, and localization of IgG immunoreactivity to the neuromuscular junction and motor neuron cytoplasm. Experimental autoimmune grey matter disease is a more acute and severe disorder involving both upper and lower motor neurons, induced in guinea pigs by inoculation of a bovine ventral spinal cord homogenate, in which scattered foci of denervation are observed in the motor cortex and ventral spinal cord. Similarities between these diseases and human ALS are reviewed.

Serum antibodies to L-type calcium channels in patients with amyotrophic lateral sclerosis

BACKGROUND AND METHODS

Sporadic amyotrophic lateral sclerosis is a chronic, progressive degenerative disease of the motor neurons of the spinal cord and motor cortex. The cause is unknown. Recent electrophysiologic studies in animals indicate that immunoglobulins from patients with this disease alter presynaptic voltage-dependent calcium currents and calcium-dependent release of neurotransmitters. To determine whether similar interactions might be identified biochemically, we used an enzyme-linked immunosorbent assay (ELISA) to detect the reaction of serum IgG with purified complexes of L-type voltage-gated calcium channels from rabbit skeletal muscle. The results from patients with amyotrophic lateral sclerosis were compared with those obtained from patients with other types of motor neuron disease, patients with autoimmune and non-autoimmune neurologic diseases, and normal subjects.

RESULTS

Serum samples from 36 of 48 patients with sporadic amyotrophic lateral sclerosis (75 percent) contained IgG that reacted with L-type calcium-channel protein, and serum reactivity on ELISA correlated with the rate of disease progression (Spearman rank-correlation coefficient, 0.62). Reactive serum was present in only 1 of 25 normal subjects and 1 of 35 control patients with no motor neuron disease. Antibodies to L-type voltage-gated calcium channels were identified in 6 of 9 patients with Lambert-Eaton syndrome, and in 3 of 15 patients with Guillain-Barré syndrome.

CONCLUSIONS

Antibodies to L-type voltage-gated calcium channels are present in the serum of patients with amyotrophic lateral sclerosis, and antibody titers correlate with the rate of disease progression. Together with previous data, these results suggest a role for autoimmune mechanisms in the pathogenesis of sporadic amyotrophic lateral sclerosis.

Ganglioside antibodies: a lack of diagnostic specificity and clinical utility?

Serum IgG and IgM antibodies to gangliosides GM1, GM2, GM3, AGM1, GD1a, GD1b and GT1b were determined in 210 patients with different degenerative and inflammatory disorders including motor neuron diseases, peripheral radiculopathies and neuropathies, multiple sclerosis and neuroborreliosis. No single disorder was associated specifically with ganglioside antibodies. No characteristic patterns of ganglioside antibodies were observed in any disease category. However, 32% of all patients had pathological antibody titres to at least one ganglioside. Four patients had pathological IgG and IgM titres for all gangliosides evaluated. They suffered from systemic lupus erythematosus [2], neuroborreliosis and schizophrenia, respectively. The results of this study indicate that the introduction of ganglioside antibody determination as a differential diagnostic test in clinical neurology is only helpful in a few patients with typical lower motor neuron syndromes.

Effects of exogenous GM1 ganglioside on LTP in rat hippocampal slices perfused with different concentrations of calcium

Combined actions of GM1 ganglioside molecules and Ca2+ ions on long-term potentiation (LTP) of the hippocampal CA1 synapses were examined in slice preparations. Application of exogenous GM1 ganglioside significantly enhanced LTP. Antigenic blocking of endogenous GM1 ganglioside by applying anti-GM1 antiserum appeared to attenuate LTP. Exogenous GM1 treatment not only antagonized LTP suppression caused by low Ca2+ (1.0 microM) in the perfusion medium, but also amplified LTP at high Ca2+ (5.0 microM) condition. Thus, GM1 may stabilize intracellular calcium levels to enhance synaptic potentiation.

Antiganglioside antibodies in motor-neuron diseases and peripheral neuropathies: study by ELISA technique and immunodetection on thin-layer chromatography

We report here our studies on IgM reactivity towards peripheral nervous system gangliosides, in motor-neuron diseases (MND) without IgM gammopathies, and in peripheral neuropathies with IgM gammopathies. We showed by enzyme linked immunosorbent assay technique, that anti-GM1 IgM antibodies were often present at a low level in normal controls in contrast to anti-GD1b antibodies, which were never detected in control sera. We evidenced that several steps of the ELISA technique were critical such as the nonaddition of detergent in buffer solutions used for dilutions and for washing and the choice of the ELISA plates. We studied 50 cases of motor-neuron diseases, among which 40 typical cases of Amyotrophic Lateral Sclerosis, only a few had high anti-GM1 antibodies levels, which were always confirmed by immunodetection on thin-layer chromatography. These antibodies were generally directed against the oligosaccharide epitope present also in asialoGM1. No correlation has been as yet established in relation to the clinical state of the patients. In a few cases of polyneuropathies associated with IgM gammopathies, antiganglioside antibodies have been reported. We have found anti-GD1b antibodies to be present in a sensory-motor axonal neuropathy; axonal involvement was evidenced by electrophysiological study.

Clinical status of motoneuron disease does not correlate with serum neurotoxicity on cultured neurons

To test the hypothesis that a serum factor may be toxic to motoneurons in Motoneuron disease (MND), we evaluated neuronal survival in dissociated cultures from chick ciliary ganglia neurons in which MND or control sera were applied. No neurotoxic activity was found when comparing neuronal survival at 1 and 3 days in MND and control group. To examine the influence of the clinical MND status on neuronal survival, we used the following parameters: age at onset, sex, months from onset of disease to sera sampling, MND form, rhythm of progression, and scoring with Appel scale. No effect was noted for any of these factors. Sera from the same patient obtained at different clinical stages did not allow any conclusion of a fixed behavior for the same patient. Our findings argue against the existence of a cytotoxic factor in sera from MND patients.

IgG anti-ganglioside antibodies and their subclass distribution in two patients with acute and chronic motor neuropathy

IgG anti-ganglioside antibodies were found in two patients with motor neuropathy. The first patient had a chronic axonal neuropathy with persistently elevated anti-GM1 antibodies. The second patient had an acute axonal neuropathy with anti-GM1, GD1b and asialoGM1 antibodies. In both, the IgG subclass study showed that the antibodies belonged to the IgG1 subclass. An enzyme-linked immunosorbent assay (ELISA) for light chains revealed anti-ganglioside antibodies of the lambda type.

Different patterns of glycolipid antibody reactivity: lower motor neuron syndromes vs. immunization

High titers of serum antibodies against GM1 ganglioside occur frequently in patients with lower motor neuron (LMN) syndromes. We compared the specificities of the antiganglioside antibody reactivities in LMN patients with those arising after immunization of Lewis rats with several ganglioside containing preparations including purified GM1, human central nervous system (CNS) grey matter and white matter. Serums with high titers of anti-GM1 antibodies from patients with LMN syndrome usually showed limited cross-reactivity to other glycolipids but often bound to a Gal(beta 1-3)GalNAc-containing neoglycoprotein. In contrast, serums with anti-GM1 antibody arising after immunization showed broad cross-reactivity with other glycolipids but did not bind to the neoglycoprotein. We conclude that the serum patterns of antiganglioside antibody reactivity secondary to immunization with gangliosides and CNS components are different from the natural autoantibodies found in LMN patients. The antiganglioside antibodies seen in LMN patients are unlikely to be a result of autoreactivity to gangliosides after nervous tissue damage.

Effect of parenteral administration of GM1 on cytokines and anti-ganglioside antibody patterns. Preliminary report in normal human individuals

To assess the effects of monosialoganglioside GM1 on some immunological parameters, 12 healthy men were treated with 100 mg GM1 i.m. daily for 15 days. Before and after treatment, the following were studied: (1) serum levels of antibodies against GM1, asialo-GM1 (aGM1), GM2 and GD1b; (2) serum levels of interleukin (IL)-1 beta, IL-2, soluble IL-2 receptor (sIL-2R), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma); (3) IL-1 beta and TNF-alpha production by peripheral blood monocytes (PBMO). Anti-ganglioside antibody and cytokine serum levels were not affected by exogenous GM1 administration with the exception of a transient increase in anti-GM1 antibody titer observed in one subject. In addition, no inhibition of IL-1 beta and TNF-alpha production by PBMO was observed. These preliminary data do not support a potential immunogenic or immunomodulatory function for in vivo administered GM1.

Clinical correlations of anti-GM1 antibodies in amyotrophic lateral sclerosis and neuropathies

Clinical correlations of antiganglioside GM1 antibodies are important because high titers of these antibodies may have therapeutic significance. To further evaluate this significance, we reviewed our experience with 78 patients who had the following diagnoses: amyotrophic lateral sclerosis (ALS), ALS syndromes in patients with gammopathy or thyroid abnormalities, cervical spondylosis simulating ALS, motor neuropathies, and chronic inflammatory demyelinating polyneuropathies (CIDP). Antiganglioside antibody titers were measured "blind" by ELISA assay at the neuromuscular clinical laboratory, Johns Hopkins School of Medicine. We conclude that anti-GM1 antibodies are found in a wide variety of neuromuscular conditions. Patients with classical ALS had a mean anti-GM1 antibody titer significantly lower than patients with CIDP or motor neuropathy. Patients with ALS associated with gammopathy or thyroid disorders had higher anti-GM1 titers than seen in classical ALS. The highest mean titer occurred in patients with CIDP, a treatable neuropathy.

Invited review: motor neuropathies, motor neuron disorders, and antiglycolipid antibodies

High titers of IgM anti-GM1 antibodies are commonly found in the serum of patients with some lower motor neuron disorders and peripheral neuropathies. Enzyme-linked immunosorbent assays (ELISA) are useful for the detection and quantitation of anti-GM1 antibodies. Testing for serum anti-GM1 activity is indicated in the diagnostic evaluation of lower motor neuron syndromes. The presence of high titers of anti-GM1 antibodies mandates careful electrophysiologic testing for the motor conduction block that is found in multifocal motor neuropathy, a treatable disorder. Quantitation of anti-GM1 antibodies may also be a useful guide in the treatment of multifocal motor neuropathy. Further study of antiglycolipid antibodies in motor neuron disorders and peripheral neuropathies may provide clues to the events that stimulate these antibodies and to the pathogenesis of such syndromes.

Autoantibodies to GM1 ganglioside: different reactivity to GM1-liposomes in amyotrophic lateral sclerosis and lower motor neuron disorders

We studied the ability of anti-GM1 ganglioside antibodies to bind to GM1 in a lipid, "membrane-like" environment. Liposomes containing GM1 were synthesized to simulate this environment. We then compared the binding of anti-GM1 a autoantibodies to GM-1-liposomes and to purified GM1. Antibody binding was quantitated using enzyme-linked immunosorbent assay methodology. Our results showed a 250-fold variation in the ability of anti-GM1 antibodies to bind to GM1-liposomes. There was no correlation between GM-1-liposome binding and the carbohydrate specificities of the anti-GM1 antibodies. However, anti-GM1 antibodies from patients with amyotrophic lateral sclerosis (ALS) showed a 4 fold greater binding to GM1-liposomes than antibodies from patients with lower motor neuron (LMN) syndromes. We conclude that a lipid, presumably "membrane-like", environment may greatly influence the degree of anti-GM1 antibody binding to GM1. The low levels of anti-GM1 antibody binding to GM1-liposomes in patients with LMN syndromes may provide a diagnostic means for distinguishing these patients from those with ALS. Anti-GM1 antibodies from patients with ALS may bind especially well to neuronal membranes containing GM1 in vivo.

Chronic acquired demyelinating motor neuropathy

A patient with chronic, acquired, demyelinating, pure or predominantly motor asymmetric neuropathy is described. Electrophysiological tests showed multifocal conduction block in motor nerves. The sensory system was intact and the first signs of slight trival involvement appeared after 4 years of disease duration. The antiganglioside antibodies were present in serum and the patient responded to immunosuppressive therapy (azathioprine). Distinction of such cases from motor neuron disease is critical since motor demyelinating neuropathy is treatable in most cases.

Motor neuron disease (amyotrophic lateral sclerosis)

Amyotrophic lateral sclerosis is an insidiously developing, adult-onset, progressive anterior horn cell degeneration with associated degeneration of descending motor pathways. It has been recognized as an important clinical syndrome since the middle of the 19th century. Despite increasing clinical and research interest in this condition, its cause remains obscure, even in the broadest terms. Epidemiologic characteristics of the disease have been interpreted as evidence of both genetic and environmental causes. A major change in the view of this disease is the widely developing perception that it is a disease of elderly persons more than of middle-aged adults as was previously taught. Etiologic hypotheses encompass a broad range of postulated pathophysiologic mechanisms, and we review these in detail. The clinical limits of the disease can now be better defined by using modern diagnostic techniques. Although interest in supportive symptomatic therapy is growing, no intervention has yet been shown to modify the biologically determined motor system degeneration.

Human monoclonal IgM with autoantibody activity against two gangliosides (GM1 and GD1b) in a patient with motor neuron syndrome

Small amounts of oligoclonal immunoglobulins were detected by Western blotting in the serum from a patient with motor neuron syndrome. The prominent one, a monoclonal IgM lambda, reacted strongly with the gangliosides GM1 and GD1b and more weakly with asialo GM1, as shown by immunoenzymatic staining of thin-layer chromatograms of gangliosides, ELISA on purified glycolipid coats and immunoadsorption with purified GM1. Affinity-chromatography with purified GM1 resulted in the purification of monoclonal IgM lambda. This purified IgM and its Fab fragments showed the same pattern of reactivity with gangliosides as that observed with whole serum. Such monoclonal IgM could be responsible for motor neuron diseases in some patients with overt or barely detectable monoclonal gammopathies.

Polyclonal IgM anti-GM1 ganglioside antibody in patients with motor neuron disease and variants

Recent studies reported the presence of anti-ganglioside antibodies in occasional patients with motor neuron disease. We found polyclonal serum IgM anti-GM1 antibodies by an anti-GM1 enzyme-linked immunosorbent assay (ELISA) in 9 (19%) of 48 patients with motor neuron disease. A comparable frequency of IgM anti-GM1 antibodies was found in 4 (10%) of 40 sera from patients with other neurological disease. Three (17%) of 18 sera from the patients with motor neuron disease and 2 (17%) of 12 sera from patients with other neurological diseases had anti-GM1 immunostaining as shown by thin layer chromatography immunoblot. One patient with a lower motor neuron variant of motor neuron disease or motor axonopathy without multifocal conduction block had a markedly elevated polyclonal IgM anti-GM1 ELISA titer (greater than 1:64,000) with prominent immunostaining of GM1, moderate immunostaining of GM2, and weak and inconsistent immunostaining of GD1b by thin layer chromatography immunoblot. Treatment with prednisone resulted in clinical improvement despite increasing anti-GM1 antibody titers. These data indicate that patients with motor neuron disease have measurable levels of anti-ganglioside antibodies as frequently as patients with other neurological diseases. This contrasts with a small subgroup of patients with a lower motor neuron variant of motor neuron disease or motor axonopathy who have markedly elevated levels of serum anti-ganglioside antibodies and a clinical syndrome that is treatable with immunosuppression.

Lower motor neuron syndromes defined by patterns of weakness, nerve conduction abnormalities, and high titers of antiglycolipid antibodies

We studied 74 patients with progressive, asymmetrical lower motor neuron syndromes. Clinical features of these patients, including age, sex, disease duration, patterns of weakness, and reflex changes, were evaluated by review of records. In each patient the clinical features were compared to the type of nerve conduction abnormalities and to the specificities of high-titer serum antiglycolipid antibodies. Antibody specificities were determined by an enzyme-linked immunosorbent assay using purified glycolipids and carbohydrates as substrates. Our results show that high titers of antibodies to glycolipids are common in sera of patients with lower motor neuron syndromes. Selective patterns of reactivity indicate that specific carbohydrate epitopes on the glycolipids are the targets of the high-titer antibodies in individual patients with lower motor neuron syndromes. Several distinct lower motor neuron syndromes can be identified based on clinical, physiological, and antiglycolipid antibody characteristics. These syndromes include multifocal motor neuropathy with evidence of multifocal conduction block on motor, but not sensory, axons and frequent (84%) high titers of anti-GM1 ganglioside antibodies; a lower motor neuron syndrome with predominantly distal weakness early in the disease course, no conduction block, and a high incidence (64%) of anti-GM1 antibodies; and a lower motor neuron syndrome with predominant early weakness in proximal muscles and serum antibodies to asialo-GM1 that do not cross-react with GM1 ganglioside.

Anti-GM1 ganglioside antibodies with differing fine specificities in patients with multifocal motor neuropathy

Antibodies to gangliosides were detected in sera from three of 19 patients with chronic inflammatory polyneuropathy (CIP) by a thin-layer chromatogram overlay technique. All three of the patients fell into a clinical subset of the group that had multifocal motor neuropathy, and in all three patients the antibodies reacted with GM1 ganglioside. However, the fine specificities of the antibodies differed as demonstrated by cross-reactivity with different gangliosides in each of the three patients. The antibodies in patient 1 reacted with GM1, GD1b, and asialo-GM1 suggesting that the terminal Gal(beta 1-3)GalNAc moiety that is common to these three glycolipids is an important part of the epitope(s). This was confirmed by showing reactivity of the antibodies with Gal(beta 1-3)GalNAc conjugated to bovine serum albumin. Patient 2 had antibodies that did not react with GD1b, but cross-reacted with GM2 ganglioside suggesting that the epitope(s) involved the inner portion of the oligosaccharide moiety that is shared between GM1 and GM2. Patient 3 had antibodies that reacted with GM1 and asialo-GM1, but they did not cross-react with either GD1b or GM2. These results provide further evidence for a relationship between motor nerve syndromes and anti-GM1 antibodies and also suggest that GM1 could be a principal target antigen since other reactive gangliosides differed among the patients. However, the possible pathogenic effects of anti-GM1 antibodies on motor nerves remain to be established.

Motor neuropathy with activity of monoclonal IgM antibody to GD1a ganglioside

A patient with motor neuropathy associated with monoclonal IgM protein is reported. Using enzyme-linked immunosorbent assays, the antibody activity of the monoclonal IgM was shown to be directed against GD1a ganglioside, a new and so far unreported specificity.

Amyotrophic lateral sclerosis: an unconventional autoimmune disease?

The possibility of an autoimmune mechanism of pathogenesis in amyotrophic lateral sclerosis has long been considered, but the evidence to support a conventional autoimmune process, reviewed here, is inconclusive. However, antibodies that react in vitro with gangliosides have recently been found in sera of a large majority of patients with classical amyotrophic lateral sclerosis and other motor neuron syndromes. A working hypothesis is proposed, suggesting how antibodies might be related to the disease process. The hypothesis attempts to account for (1) a pathogenic role of antibodies directed against the carbohydrate components of glycolipids, (2) the selectivity of the process for motor neurons, (3) an antibody-mediated mechanism that could result in apparently degenerative neuropathological changes without signs of inflammation, and (4) a type of autoimmune response that is extremely difficult to suppress by conventional means. Although the evidence for this hypothesis is by no means complete, its critical features are all testable.